Abstract proceedings dwrp10 - final.doc
4th Annual Meeting of
DANISH WATER RESEARCH PLATFORM
DWRP ER IDENTISK MED FORSKNINGSPLATFORMEN VAND
Abstracts proceedings of the 4th Annual Meeting of The
Danish Water Research Platform (DWRP) –
Forskningsplatformen Vand
Date: 28 – 29 January, 2010 Venue: The geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K. Contents
Session 2: Water and climate
Session 3: Water resources
Session 5: Detection and sensor systems
Session 6: Water and agriculture
Session 7: Public-private RTD cooperation
Session 1: Groundwater
Optimisation of groundwater well field management
Henrik Madsen1
Abstract
Groundwater management at well fields includes a number of operation objectives, such as system
reliability, operation and maintenance costs, energy consumption, environmental impacts, and water quality.
Numerical modelling of well-fields can be used to analyse different operation strategies to provide more
cost-effective water withdrawal and pump scheduling schemes while at the same time minimising the
adverse impacts.
An integrated, dynamically coupled hydrological and hydraulic well-field modelling system has been
developed for modelling the flow of water in the groundwater aquifer, through the wells and pipe system to
the waterworks. The model combines a groundwater model (MIKE SHE), a well model (based on the multi-
node well model in MODFLOW) and a pipe network model (EPANET). The integrated modelling approach
allows a detailed simulation of the abstraction from the different wells in the well field, which depends on
the hydraulic properties in the aquifer, wells, pumps and pipe network.
For optimization and control of well field operation the numerical model is coupled with an optimization
algorithm. The integrated simulation-optimization system can be used as a planning tool to optimize well
field designs and pump configurations. In addition, optimization can be used on-line for real-time control to
provide optimal pump scheduling according to given demands. The real-time control system allows the
simulation-optimization system to continuously adapt to both short-term and long-term dynamic changes in
the well field.
Acknowledgements
This work is partly funded by the Danish Strategic Research Council, Sustainable Energy and Environment
Programme and the Danish Water and Waste Water Association, Research Programme on Energy Savings.
For more information visit http://wellfield.dhigroup.com/.
1([email protected]), DHI, Agern Allé 5, DK-2970 Hørsholm, Denmark
The impacts of microbial processes and hydrogeological parameters on chemical gradients in
porous groundwater systems
Florian Einsiedl1
Abstract
Groundwater resources are of global significance for drinking water. In many countries groundwater delivers
more than 50% of current potable water and is indispensable for both agriculture and industries. However,
groundwater is threatened by local point or diffuse pollution through leaching of pesticides and nitrate. In
this study we coupled groundwater age dating, stable isotopes in groundwater nitrate (δ15N, δ18O), sulphate
(δ34S, δ18O) and water chemistry data obtained from a high resolution multi-level well to interpret chemical
gradients in a heterogeneous porous groundwater system.
Generally, chemical gradients are indicators of redox boundaries caused by active microbial degradation
processes. Via modelling results using a dispersion model coupled to a long tritium record and stable
isotopes in nitrate we demonstrate that biogeochemical gradients observed in the upper part of the aquifer are
formed by mixing of old and young groundwater, with the latter affected by high anthropogenic N input.
Furthermore we found some evidence by the application of environmental tracers that the long mean transit times in the groundwater system are regulated by the thickness of the unsaturated zone and not by local aquifer heterogeneity. On the other hand, our approach also provides multiple lines of evidence that chemical gradients in the deeper part of the groundwater system are regulated by microbial processes. Furthermore, the multiple isotope approach shows that anoxic pyrite oxidation may represent the electron donor for denitrification in a carbonate buffered groundwater system. This study demonstrates the importance of incorporating both hydrogeological and biogeochemical analyses in a complex porous groundwater system to understand groundwater ecosystem functioning. 1([email protected]), DTU, Department of Environmental Engineering, Technical University of Denmark Miljøvej Bygning 113, DK-2800 Kgs Lyngby, Denmark
Groundwater Salinity in Greve, Denmark – Modelling and Management of the Municipality's
Groundwater Resource
Paul Thorn1
Abstract
Elevated salinity (chloride levels greater than 250mg/l) in groundwater wells near the Municipality of
Greve's coastline has been observed since the 1970's. Due to the proximity of the wells to the coast, it was
traditionally thought that the salinity observed in the wells resulted from seawater intruding into the aquifer
from the Baltic Sea. However, a recently released study by GEUS has indicated that the observed salinity
could be via diffusion of saline connate pore waters in the chalk aquifer. This has a significant impact for the
management of the groundwater, as if the source is from connate formational waters, the slow rate of the
diffusion of the salts will not allow the salinity to rise. In contrast, if the salinity is from seawater intrusion,
levels could significantly increase, polluting the wells. This study uses historical groundwater quality data
(from 1970-2008) from bulk-water samples, combined with a geological model of the municipality in order
to produce a conceptual model for the source of salinity observed in Greve.
The geochemical data from the wells suggest that there are two distinct groundwater types within four
kilometres from the coastline. Thus the groundwater can be divided up into two separate districts, a northern
and southern district. In the northern district, the geochemical data show bicarbonate and sodium rich
groundwater. In addition, the sodium to chloride ratio is close to or over one. This suggests that the waters
are undergoing freshening. The southern district has relatively chloride and calcium rich groundwater, as
well as sodium to chloride ratios at or below 0.7. This suggests that seawater is intruding into the aquifer.
The observed temporal changes in salinity also illustrate. The wells from the northern district show no
temporal trend in salinity – the salinity remains at the same level from when the well was drilled to the
present. In addition, the wells closer to the shoreline do not show a higher salinity level. In the southern
district, the wells show a tendency for increased salinity over time, with the wells closest to the coast
showing increasing salinity first, and have the highest levels (with one well increasing from 50mg/l Cl to
2200mg/l Cl over a 5-year period). Thus, it is apparent that the groundwater in the southern district is
experiencing seawater intrusion, where as the salinity from the northern district is from the connate
formational water.
The geology of the area provides an explanation as to why there is a difference between the two groundwater
districts. In Greve, the primary groundwater aquifer is fractured Maastrictian chalk overlain by 5m-25m of
glacial deposits. In the northern district, the glacial deposits are primarily clayey tills, with thicknesses of
over 20m along the coastline. The clayey till acts as an aquiclude, preventing seawater from intruding into
the aquifer. In the southern district, there is a thick lens of glacial outwash sands and gravels extending to the
coast. This lens provides a conduit for saltwater to intrude into the aquifer.
The results have significant impact for the management of the groundwater in the municipality. As the elevated salinity in the northern district is from connate formational waters, these levels will not increase with the continuation or even increase in groundwater abstraction. However, in the southern district, there is a significant threat for saltwater intrusion into the aquifer. Thus, abstraction wells need to be monitored, and abstraction rates need to be reduced if seawater intrusion intensifies or moves further inland. In addition, new wells should not be located in this area. 1([email protected]), Roskilde University, Department of Environmental, Social and Spatial Change, Hus 02, Universitetsvej 1, 4000, Denmark.
3D regional scale hydrostratigraphic modeling based on sequence stratigraphic methods: a
case study of the Miocene succession in Denmark
Peter Scharling1
Abstract
A sound hydrogeological model is the heart of every well performing groundwater model. A sequence
tratigraphic approach has been tested, which has been widely used in the petroleum industry since the
1980s for the construction of three-dimensional (3D) hydrogeological models for sedimentary basins. The sequence stratigraphical interpretation has been established for the Miocene succession in western Denmark based on seismic profiles, gamma-ray logs, sediment descriptions and palynological analysis of borehole samples. The up to 400 m thick Miocene succession consists of deposits originating from deep marine to terrestrial depositional environments. The succession is subdivided into six sequences, corresponding system tracts and distinct lithofacies covering the period from late Oligocene to latest late Miocene. The final model is converted into a binary 3D model that shows the location, geometry and thicknesses of potential deep aquifers, and is prepared for groundwater flow modeling. The model provides a qualified geological description of the connectivity between deep sand formations and the ground surface. By comparison to a traditional lithofacies model based on sediment descriptions of borehole samples, it is shown that the new method gives a more sound geological understanding, which is essential when flow paths and the vulnerability of deep aquifers are evaluated. 1 Geological Survey of Denmark and Greenland (GEUS), Department of Hydrology, Øster Voldgade 10, 1350 Copenhagen K, Denmark
Session 2: Water and Climate
Design practice for urban drainage including climate change impacts
Qianqian Zhou1, Karsten Arnbjerg-Nielsen1, Peter Steen Mikkelsen1, Susanne Balslev Nielsen2, Kirsten Halsnæs3
Abstract
An increase in precipitation intensities has been observed in Northern Europe, most likely due to the climate
change. Incorporating the anticipated climate change impacts into design of urban drainage has been a big
challenge for engineers and will have substantial impact on the overall cost of urban drainage in terms of
investments and/or damage.
The presentation will focus on preliminary work on the increased risk of flooding, i.e. exceeding the design
criteria. Analyses of flood risk are performed by a combination of hazard and vulnerability assessment of the
physical impacts and economic losses. A simplified conceptual catchment is carried out in Mike Urban to
model flooding impacts with linkage to hazard indicators, such as water extent, depth and velocity. The
generation of flooding on a regular catchment due to extreme rainfall events is described in relation to
catchment parameters, such as size, slope, roughness, drainage capacity, local pressures, etc. The
vulnerability assessment is mainly with respect to the quantification of the monetary losses and intangible
effects induced by flooding. The methodologies of quantifying environmental service flows and intangible
goods are studied and incorporated in the cost function. The objective is to derive flood damage cost function
that links to the catchment characteristics to provide economic background for further evaluation and
adaptation tools.
Mass balance analysis of the distribution between runoff in sewage and overland flow depending on time
1([email protected]), DTU Environment, Department of Environmental Engineering, Technical University of Denmark
Miljøvej Bygning 113, DK-2800 Kgs Lyngby, Denmark, 2 DTU Management, 3 DTU Risø
Impact of alternative bias corrections on climate projections and predicted pesticide leaching
Torben O. Sonnenborg1 and Peter van der Keur1
Global climate models are often downscaled using regional climate models to obtain a better description of the physical parameters and processes. The results from the regional climate models are, however, not accurate enough to be used as direct input to hydrological impact models. Therefore, bias correction of the climate model results is needed. In this study four different bias correction methods have been tested on results from regional climate model. In two methods the scenario climate is based on the historical climate whereas for the other two methods the results from the climate model is used as baseline for the scenarios data. The methods are based on data from 1961-1990 and validated on data from the period 1991-2006. The difference between the four methods for the scenario period 2071-2100 is quantified by statistical means. The impact of bias correction method is tested with respect to simulated pesticide leaching from the root zone for two different locations, one dominated by sandy soils and the other by clayey soils. Especially for the clayey soil dominated by macro-pore transport the choice of bias-correction is found to be important.
1 Geological Survey of Denmark and Greenland (GEUS), Department of Hydrology, Øster Voldgade 10. 1350 Copenhagen K, Denmark
Three Points Approach for urban flood risk management: adapting to climate change
through transdisciplinarity and multi-functionality
C. Fratini1+4, G.D. Geldof2+4, J. Kluck3 and P.S. Mikkelsen4
Abstract
Urban flood risk is increasing as a consequence of climate change and growing impervious surfaces.
Increasing complexity of the urban context, gradual loss of tacit knowledge and decreasing social awareness
are leading to inadequate maintenance of urban infrastructures. The European Flood Directive sets clear
requirements and emphasises the need for a paradigm change in favour of non-structural measures aimed at
urban resilience and social preparedness. The Three Points Approach (3PA) provides a structure that
facilitates the organization of the decision making process dealing with urban flood risk management
(UFRM) by enhancing the use of transdisciplinarity and accepting the complexity of the urban context. The
3PA introduces three domains where the decision makers may act (1) technical optimization, dealing with
standards and guidelines; (2) spatial planning, to make the urban area more resilient to future changing
conditions; (3) day to day values, to enhance support and awareness among the stakeholders. This study
demonstrates the validity of the 3PA and describes how it can be used in practical UFRM. A multilevel
approach to knowledge was employed to understand the mechanisms driving complex adaptive systems, like
nature and society, characterizing the urban area and thus apply the 3PA in practice. Two case studies were
analysed in the Netherlands and in Denmark with the 3PA. This analysis demonstrates the validity of the
3PA for UFRM and highlights the differences between the two countries in approaching the decision making
process, drawing attention to the importance of culture in projects. We conclude that the 3PA offers decision
makers an innovative perspective on UFRM and is ready to be used to organize strategy plans for urban
adaptation to climate change.
Figure 1. The Three Points Approach scheme. Both the axes are on a logarithmic scale. The horizontal axis
represents the return period and the vertical axis represents the size of the flooding in terms of the cost of the
nuisance/damage/-danger caused to the urban area and its inhabitants.
1 Corresponding author, ([email protected])1 Department of Management Engineering, Technical University of
Denmark, Lyngby, Denmark.
2 Geldof c.s., Tzum, the Netherlands
3 Tauw bv, Water Department, Deventer, the Netherlands
4 Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
Session 3: Water resources
How to assess groundwater abstraction impact on in-stream physical habitat conditions in
small lowland streams
M. Olsen1, E. Boegh1, J.C. Conallin1, H.J. Henriksen2, J.C. Refsgaard2, L. Troldborg2
Abstract
After inventory of the sustainable Danish groundwater resource in 2003 one of the conclusions was that
consideration of minimum flow requirements in streams was most limiting for the size of the groundwater
resource. This revealed special challenges in regard to impact assessment from hydrological conditions e.g.
groundwater abstraction on in-stream ecological conditions. Groundwater abstraction affects low flows
critical to in-stream ecological conditions in particular and it is well known that large scale water resources
models often are developed with a focus on simulation of annual water balance and hydrograph shape rather
than low flow.
The objective of this study was to assess if it was feasible to combine in-stream environmental flow criteria
with an integrated surface-groundwater model (in this case the Danish national water resources model, DK-
model) to quantify groundwater abstraction impacts on in-stream physical habitat conditions.
The island of Zealand, Denmark, was used as case area and brown trout (Salmo trutta) as indicator of in-
stream habitat conditions. The brown trout was chosen since it is often used as environmental indicator in
streams and recently there has been a huge advance in the knowledge on brown trout in-stream habitat
requirements in Danish streams. A calendar of "Ecological Critical Flows" (ECF) was established for
streams on Zealand using local expert knowledge. For each month the ECF-calendar indicates if high or low
flow is critical for brown trout habitat conditions. Simulated and observed stream flow from 49 flow gauging
stations included in the DK-model was used to assess flow simulation error and in-stream flow criteria;
critical low flow criteria (Qlow), optimal flow criteria (Qopt) and critical high flow criteria (Qhigh). One Qlow
and one Qopt was assessed by combining general hydraulic geometry functions for water depth (D) and water
velocity (V) in streams on Zealand with brown trout D and V requirements.
The ECF-calendar divides the year into 3 periods; April-June where high flow is critical for brown trout,
July-October where low flow is critical and November-March where flow most often is not critical. Flow
simulation error and bias is relatively largest for the lowest flows and is most pronounced in the July-October
period where low flow is critical for in-stream habitat conditions. Simulation of Qlow is associated with large
uncertainty and bias since all estimated Qlow is in the flow range where the DK-model overestimates flow by
more than 100%. The DK-model is better at simulating Qopt than Qlow since estimated Qopt-values are in the
flow range where overestimation is less than 100%.
The study revealed that low flow criteria and the DK-model at present are not suited for each other due to
different focus. The finding emphasises that stream ecologists and hydrologist typically focus on different
aspects of the hydrological regime. In-stream environmental flow criteria for use in water management
should be ecologically relevant and easily understandable for both stream ecologists and hydrologists in
order to bridge the gap between the two disciplines and achieve true integrated water management. In our
opinion a tool like the ECF-calendar is a useful base for positive interaction between stream ecologists,
hydrologists and modellers to establish and improve integrated water resource managements tools.
Furthermore different approaches are needed at different spatial scales, i.e. flow criteria that are used at large
scale should be adapted to large scale water resources model, while flow criteria and hydrological models
should be improved and validated for local scale investigations in order to better simulate ecologically
relevant flows. When targeting flows from the ECF-calender in hydrological model calibration high quality
observation data representing low flow from flow gauging stations collected at the local scale and improved
water balance input data are required.
This study was part of the research project "Groundwater abstraction and climate change impacts on ecological conditions in streams" (www.ecohydrology.ruc.dk) which is financed by the Danish Research Council for Technology and Production, 2007-2009. 1 ([email protected]), Roskilde University, ENSPAC, Bygning 02, Universitetsvej 1, DK-4000 Roskilde, Denmark 2 Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
A new DK-model concept for nutrient loading calculations (DK-NP)
Jørgen Windolf1, Søren E. Larsen, Hans Thodsen, Jens Bøgestrand, Niels B. Ovesen og Brian Kronvang
Abstract
A new model concept has been developed that enables a harmonised calculation of monthly total nitrogen
(N) and total phosphorus (P) loadings of surface waters (lakes and coastal waters). The model concept
utilises data from a network of downstream monitoring stations in Danish streams established back in 1989
(coastal loading network). Today it consists of 113 monitoring stations covering 49% of the Danish land
area. The remaining of the land area is unmonitored and hitherto different methods have been utilised to
estimate N and P loadings. A NOVANA project running from 2006-2009 where also runoff from ungauged
areas were modelled (DKQ model), has made it possible to develop a new model concept that can be utilised
all over the country. We have recently finished the recalculation of monthly N and P loadings to coastal
waters around Denmark for the period 1990-2008 utilising the new DK-NP model concept.
The core of the model concept is two statistical models predicting discharge weighted concentrations of N
and P from diffuse sources (mainly agriculture) being developed based on ongoing monitoring results from
80 catchments for N and 24 catchments for P, the latter having water sampling done continuously with
automatic samplers for a 8-year period. The statistical models has been utilised to estimate the diffuse
loadings to freshwater from a series of 25 km2 catchments in the unmonitored parts of Denmark by
multiplying the modelled concentrations with DKQ modelled runoff values. For validation reasons the N
model has been applied to the monitored areas as well and deviations between monitored and model
estimated N loadings has been evaluated in different Georegions and for specific monitored catchments. The
model concept also includes new procedures for estimating retention of N and P in streams, rivers, wetlands
and lakes. In the case of 611 larger lakes the lake specific N retentions have been modelled chaining all lakes
and catchments within a watershed and modelling incoming water and N for use in a N-retention model.
Stream, river and wetland retention is modelled utilising simple reduction rates for the different types after
having depicted and assessed the individual water bodies with algorithms embedded in GIS.
The newly recalculated nutrient loadings can be compared with loadings calculated with methods formerly
used. Methods used in earlier calculations of nutrient loading were not strictly standardised but partly based
on varying assumptions and methods used and reported by the former counties. For the period 1990-2005
recalculated mean nitrogen loading is 6.6% less than previously reported with annual deviations ranging
from 0 to -15%. Contrary for phosphorus recalculated mean loading (1990-2005) is 6% higher than
previously reported with annual deviations ranging from -10% to 15%. On a regional and local scale these
deviations obviously can be marked higher than the ones for the national loadings.
We intend in the future to further develop and validate the new model concept improving the different
retention models and create tighter linkages to the model calculated Nitrate leaching from the root zone on
agricultural and non-agricultural land.
1 ([email protected]), Department of Freshwater Ecology, National Environmental Research Institute, Aarhus University.
Valuation of water quality improvements in the Water Framework Directive: valuation
results, benefit transfers and the practical use in WFD implementation
Berit Hasler1, Marianne Källstrøm, Sisse Liv Brodersen
Abstract
The aim of this study is to test benefit transfer related to the implementation of the Water Framework
Directive in Denmark. By benefit transfer we mean transfers of benefit results from one study site to policy
sites, and hereby make use of the often costly results in policy assessments in other sites. The notion benefits
are used for the environmental improvements of the WFD, by valuation studies these benefits are expressed
in monetary terms. Because valuation studies are so expensive to conduct benefit transfer can be a cost-
effective alternative as compared to primary valuation studies of the aquatic environment, but this only hold
if the benefit transfers can be done without to large transfer errors.
The results from a stated preference study in Odense Fjord and Roskilde Fjord is used for the test of unit
benefit values as well as benefit functions between these two Danish fjords. In both areas a similar
questionnaire has been submitted to a representative number of households at Funen/Southern Denmark and
Zealand, respectively. The questionnaire contains questions on the use of the fjords as recreational area -
where they go most frequently, the frequency and what they most often do-, the households' address (both
home address and second home address), socio economic variables such as age, gender, income and
educational level in addition to valuation questions. Both studies contain two types of valuation questions (a
contingent valuation question and a so-called choice experiment) but in this benefit transfer we only present
the contingent valuation results. The improvements of the ecological conditions in the fjords from bad and
moderate conditions to good ecological conditions are presented using a generic water quality ladder,
developed for use in the EU-project AQUAMONEY (Bateman et al, 2009; Hasler et al 2009).
For both fjords benefit functions are estimated, and the parameters in the benefit functions are compared.
Comparison of the parameters, i.e. the preferences for the two areas, are done by testing the hypothesis H0: b1
= b2 and H1: b1 ≠ b2 , where b1 and b2 are the estimated model parameters for the two fjords. If Ho is accepted
and H1 is rejected this is an indication of that the results/benefit functions are suitable for benefit transfer to
other areas in e.g. Denmark.
The results indicate that the benefit transfers between the two fjords results in very low transfer errors, and
this result is promising for use in the WFD implementation.
References:
Bateman I. et al (2009) Testing water quality benefit transfer. Paper presented at the EARE conference, Amsterdam,
June 2009.
Hasler B. et al: Case study report Denmark. Aquamoney: valuation of water quality changes. In press.
1([email protected]), Aarhus University, National Environmental Research Institute, Department of Policy Analysis,
Frederiksborgvej 399, Postbox 358, DK 4000 Roskilde
Nitrate reduction in geologically heterogeneous catchments (NICA)
Jens Christian Refsgaard1 and Britt SB Christensen2
Abstract
The nitrate load from agricultural land to lakes and coastal water in Denmark has during the past 20 years
been reduced by about 50% by government regulations imposed on agricultural practice. The EU Water
Framework Directive (WFD) requires that good ecological status be achieved for all water bodies by 2015
and prescribes that surface water and groundwater resources are managed in an integrated context. This will
require an additional reduction of nitrate load by 50%, which economically will be very painful for the
agricultural sector. The regulations imposed until now have been general, i.e. the same restrictions for all
areas independent on the subsurface conditions. Studies have shown that on a national basis about 2/3 of the
nitrate leaching from the root zone is reduced naturally in the subsurface before reaching the streams. This implies that if a general agricultural regulation reduces nitrate leaching by 100 kg N, the nitrate load to surface water will only be reduced by 33 kg N. Therefore it is much more cost-effective to identify robust areas, where nitrate leaching through the root zone is reduced in the saturated zone before reaching the streams, and vulnerable areas, where no subsurface reduction takes place, and then only impose restrictions on the vulnerable areas. Distributed hydrological models can make predictions at grid scale, i.e. at much smaller scale than the full catchment. Hence these models have a potential for being able to differentiate between robust and vulnerable areas. However, in all previous studies we have seen, distributed models do not have predictive capability at scales much smaller than catchment scale. A constraint in this respect is that distributed models often do not include local scale hydrogeological heterogeneities that are known to be important for reactive transport. NICA (Nitrate reduction in geologically heterogeneous catchments) is a new research project that will develop tools for assessing nitrate reduction in the subsurface between the root zone and the streams and methodologies for assessing at which spatial scales such tools have predictive capabilities (see the enclosed figure). A new instrument will be developed for airborne geophysical measurements, MiniSkyTEM, dedicated for identifying geological structures and heterogeneities in the upper 30 m. State-of-the-art hydrological models (DAISY, MIKE SHE/MIKE11, HydroGeoSphere, RWHET) will be applied and the effect of geological heterogeneity will be analysed by use of stochastic geological realisations such as TProGS. A new concept, Representative Elementary Scale (RES), will be developed for assessing the minimum scale at which models, with a given data input, potentially have predictive capabilities. The studies will be conducted in a 10 km2, densely instrumented catchment and tested in a 101 km2 catchment, where farmers and authorities will be actively involved in evaluating possible measures for reducing the nitrate load to surface water in a cost-effective manner. The economic gain from a cost efficient location of the measures will be evaluated. The talk will present the project idea. 1 ([email protected]), Geological Survey of Denmark and Greenland (GEUS), Department of Hydrology, Øster Voldgade 10. 1350 Copenhagen K, Denmark 2 ([email protected]), Geological Survey of Denmark and Greenland (GEUS)
Session 4: Urban water
The hydrological possibilities and consequences of using sustainable urban drainage systems
in Copenhagen
Jan Jeppesen1,2 and Steen Christensen2
Research project: Black, Blue & Green – Integrated infrastructure planning as key to sustainable urban water
systems (www.2BG.dk).
Abstract
The research project Black, Blue & Green – Integrated infrastructure planning as key to sustainable urban
water systems (2BG) explores the possibility for a paradigm shift within urban water systems towards local
storm water management.
In order to significantly reduce the contribution of storm water to existing sewer systems, massive storm
water infiltration to the groundwater system might be a key solution. Whether or not this is possible depends
on the levels and dynamics of groundwater. A product of the 2BG project is therefore an urban hydrological
model capable of quantifying the total urban water cycle with emphasis on interactions regarding the
groundwater system on catchment scale. The urban water cycle is described in terms of root zone water
balance, water supply, waste water, storm water, groundwater flow between geological layers, sustainable
urban drainage systems (SUDS), and the interactions between these systems. Application of the model
(without SUDS) is demonstrated for the Copenhagen area for the period 1850-2003, whereby the complete
history of groundwater abstraction and major city development in the region is covered. Observations of
historical hydraulic head data, stream discharge, and inflow to sewage works are used to calibrate and
validate the model.
Furthermore the urban hydrological model, including the SUDS utilities, is demonstrated thoroughly for the
2BG joint-case area (16 km2 of the Harrestrup Å catchment in Copenhagen). For this area it is estimated that
60 % of the storm runoff must be disconnected the sewers in order to fulfill the objective of reducing the
number of combined sewer overflows to Harrestrup Å to less than one each year. This 60 % disconnection
forms the basis for a SUDS-drainage scenario which is simulated for the period 1991-2003. In the scenario
the disconnected storm runoff is directed to infiltration areas (36 %), swale-trench systems (26 %), soak-
aways (8 %), rain tanks (6 %), green roofs (10 %), and to streams (14 %), respectively.
Although it is attempted to direct the majority of the disconnected storm runoff to "green" SUDS (which
include evapotranspiration) more than 50 % of the total input to the SUDS infiltrates to the groundwater
system. As a result the groundwater recharge increases with 56 % compared to the reference situation
without SUDS. The consequence is a dramatic rise in the groundwater table and a need for significant near-
surface groundwater drainage. The main reason for this is the presence of a low-permeable capping layer of
till and the close proximity to the sea.
Based on the model scenario it is recommended to only apply controlled storm water infiltration through
green SUDS in the case area. Controlled storm water infiltration can be achieved by: (1) minimizing the
storm water input to infiltration-based SUDS or (2) applying drains to the underground SUDS-structures
whereby the position of the groundwater table is controlled. The latter may be a promising solution to both
reduce / delay storm water and to drain ground water (which may rise anyway due to climate changes). In
selecting the optimum SUDS drainage strategy the model has proven to provide excellent decision support.
1 ( [email protected]) Alectia A/S, Skanderborgvej 190, DK-8260 Viby J, Denmark.
2 ([email protected]) Department of Earth Sciences, University of Aarhus, Ny Munkegade, Bld. 1520, DK-8000 Aarhus C,
Denmark.
Monitoring of gas bubbles in rapid sand filters
Laure Lopato1, Philip Binning, Erik Arvin
Abstract
Air bubble formation in rapid sand filters can decrease drinking water treatment efficiency. Recently there
has been increased interest in formation of air bubbles during rapid sand filtration due to dissolved gas
supersaturation in the inlet water. Air bubbles reduce water saturation in the filter bed, contribute to head
loss, decrease residence time, and increase turbidity measured at the outlet. To address this problem,
waterworks rely on backwashing to periodically remove built up gases.
This study aims to develop a new diagnostic tool to be used in waterworks to characterize and quantify the
amount of air bubbles trapped in rapid sand filters. This new method employs reactive sodium sulfite tracer
that can be injected and monitored in the filter. It is developed and tested in laboratory column experiments.
The experimental set up was designed to reproduce the formation of bubbles in the porous media during
rapid sand filtration. In this set of experiments, particle and soluble contaminant filtration was neglected and
distilled water was used as inlet water. To simplify the analysis of bubble formation, inlet water was
saturated with oxygen and the concentration of other gases was negligible. Experiments were conducted in a
63x63x313 mm3 transparent column packed with 1 mm diameter glass beads. The water flowed downward
in the column. The decrease in water content in the column was monitored by weighing the column
continuously using an electronic balance. The column was periodically backwashed to remove built up gas
bubbles. Tracer tests were performed during the experiment. A volume of 2 ml of a solution of 60g/l of
sodium sulphite was injected into the column. Because sodium sulfite is a salt, an oxygen scavenger and a
base, three breakthrough curves could be obtained after each pulse injection of the tracer: conductivity,
dissolved oxygen and pH. The column was digitally photographed every 30 min for the duration of the
experiment using a digital camera.
As the experiment proceeded and the amount of trapped gas increased, the breakthrough curves evolved. The
value of longitudinal dispersivity of the conductivity curves increased with filtration time suggesting that
bubble formation produced changes in the flow structure. The changes in the breakthrough curves could be
related qualitatively to the increasing amount of oxygen present in the column using column mass and
photographic data.
The new tracer method developed in this paper is useful to monitor the development of oxygen bubbles in
the column. It could therefore be an innovative and valuable tool for investigating the presence of air bubbles
in the filter bed of rapid sand filters at waterworks.
1 ([email protected]), Department of Environmental Engineering, Technical University of Denmark Miljøvej Bygning 113,
DK-2800 Kgs Lyngby, Denmark.
Model based prediction of micropollutants fluxes in stormwater treatment systems
L.Vezzaro, E. Eriksson, A. Ledin, P.S. Mikkelsen1
Abstract
Stormwater treatment facilities are becoming essential elements in the strategies for reducing water pollution
from urban areas. When elaborating pollution control strategies, urban water managers should be able to
assess, compare and select the most appropriate treatment option (also called Best Management Practice -
BMP) according to the specific condition of their system. However, when dealing with micropollutants
(MPs), this assessment is affected by a general lack of information regarding BMPs performances.
The dynamic Stormwater Treatment Unit model for MPs (STUMP) was developed to simulate MP fluxes in
stormwater BMPs based on the substance's inherent properties. An existing stormwater retention pond in
Stockholm (Sweden) was simulated. The STUMP results (e.g. Figure 1, left) were compared with other commonly applied multimedia models, which can be applied to estimate MP fluxes in BMPs. Two metals (Cu and Zn), and four intrinsically different organic micropollutants were selected and simulated: iodopropynyl butylcarbamate (IPBC, CAS number 85045-09-6) as "average" substance, benzene (CAS no. 71-73-2) as volatile substance, glyphosate (CAS no. 1071-83-6) as biodegradable substance and pyrene (CAS no. 129-00-0) as strongly sorbing. The STUMP can be easily adapted to simulate the investigated system and provides dynamic results that are useful to evaluate the behaviour of the BMP during rain events. The results of global sensitivity analysis suggested that the processes driving the removal of total suspended solids (TSS) were the most sensitive for the estimation of MP fluxes in the analyzed system. Therefore the calibration of TSS parameters can reduce the uncertainty of estimated MP fluxes when no MP measurements are available. The uncertainty of the STUMP simulated fluxes for copper and zinc were estimated by applying the Generalized Likelihood Uncertainty Estimation method for the available measurements. The pond removal rate calculated by the parameter sets covering 50% of the measured concentration (Figure 1 – right) showed good agreement with the measured removal. The STUMP model provides reliable prediction of the MP fluxes in stormwater treatment systems, enabling the quantification of the potential MP removal. As data often represent an obstacle in the simulation of MPs, the STUMP model requires a limited amount of information that is usually available (TSS measurements) or can be retrieved from literature (MP inherent properties). The STUMP model can thus be an important tool for urban water managers in the assessment of strategies for the reduction of stormwater pollutant emissions.
Figure 1. Estimated MP fluxes for benzene (on the left) and prediction bounds for copper concentration in the pond outlet (on the right) 1([email protected]), DTU Environment, Building 113, Miljoevej, 2800 Kgs. Lyngby, Denmark
Confronting the problem of implementing sustainable urban drainage systems
- An interdisciplinary case study project in Copenhagen
Ole Fryd and Antje Backhaus1
Abstract
Climate change will lead to more intensive rain events in Northern Europe (IPCC 2007) and conventional
sewer based solutions are reaching their technical and economical limits. Complementing strategies are
necessary.
The purpose of this paper is to present a multi-level and trans-disciplinary approach to the planning and
implementation of sustainable urban drainage system (SUDS) retrofits in existing urban areas. Applicability
and implications of the approach were discussed based on a case study that was carried out in 2009 in an area
covering approximately 1/6 of Copenhagen municipality. A team of 8 PhD students in landscape
architecture, hydrology, environmental chemistry, economy and urban planning collaborated on the design research project with end-users from the City of Copenhagen and the water utility Copenhagen Energy Ltd. Data screening and the analysis of existing municipal planning goals in combination with a first groundwater simulation resulted in an initial catchment level strategy. Based on this strategy a number of representative focus areas were identified for further detailing at site and neighbourhood level. At the single sites additional landscape architectural and hydraulic investigations showed chances and challenges for the work with SUDS. These evaluations at site level led back to a qualification and adaptation of the overall catchment strategy. Parallel to this iterative working process, aspects of environmental chemistry, economy and stakeholder involvement were examined.
This interdisciplinary working process finally led to a number of recommendations for Copenhagen municipality and to a possible SUDS implementation strategy of "combined disconnections" for the city. Core of the catchment strategy are three different area types where different measures for SUDS implementation are recommended (see map). In the most northern part of the area (area type 1), on-site infiltration and an intensive collaboration with the single house owners for the promotion of rain gardens, infiltration trenches etc. are recommended. The single point measures on private ground should be combined by public linear overflow structures. In the areas where the municipality aims to develop green links between existing green areas (area type 2), green "park-ways" that also handle stormwater run-off are recommended. In areas that slope towards green areas and open water ways (area type 3) a strategy that focuses on delay and transport is recommended. Existing streets should be transformed to transport the water to the recipients e.g. by the implementation of open gutters or rain beds.
Map of the catchment strategy
This differentiated strategy could help to release the existing sewer
system, reduce the risk of soil saturation and at the same time improve the overall green appearance of the city. 1([email protected]), Danish Centre for Forest Landscape and Planning, University of Copenhagen Rolighedsvej 23, DK-1958 Frb, Denmark
Session 5: Detection and Sensor Systems
Characterization of a cantilever based detection system for a BAM pesticide assay
Michael Bache1
Abstract
A BAM (2,6 dichlorbenzamide) pesticide residue assay has been performed using a cantilever based
detection system. The stress induced by the bonding of Anti-BAM antibody to BAM molecules immobilized
on a cantilever surface is measured using a built in piezo element in the cantilever that changes its resistance
under deformation. A series of successful experiments have been conducted successfully and the assay is
currently being improved and characterized.
During the last 10 years an increasing number of water wells in Denmark has been polluted by pesticides or
its break down products. Pesticide analysis of drinking water is currently being done by manual sampling
and laboratory analysis. This means weeks in between sampling and the analysis result. An in-line sensor
will therefore be beneficial for water quality monitoring. The project is a part of the SENSOWAQ (sensors
for monitoring and The project is a part of the SENSOWAQ (sensors for monitoring and control of water
quality) and is done in collaboration with GEUS (The Geological Survey of Denmark and Greenland) DHI
and other private and government collaborators.
The detection of BAM is done by a competitive immunological reaction. The BAM molecules from the
water sample compete with BAM attached to the surface of a cantilever for the binding to a BAM antibody.
Binding of a BAM antibody to the surface of the cantilever will change the surface stress, causing the
cantilever to bend, the bending is then detected by a change in resistance in the piezoelectric layer of the
cantilever. The detection mechanism is in principle label free, but the antibodies have been marked to
subsequently verify the bonding on the cantilever surface. The Schematic drawing and actual pictures of the
cantilever sensor can be seen in the left pictures.
The BAM assay has given repeated positive measurements on a cantilever system. Fluorescent labelling of
the antibodies has verified the attachment of antibodies on the cantilever surface. The picture on the bottom
left shows a change in signal from the attachment of BAM antibodies to a cantilever coated with BAM
molecules.
1 DTU Nanotech, Ørsted Plads, Building No. 345 Ø, 2800 Kgs Lyngby.
Immunoassay based electrochemical sensor for quantitative detection of BAM in ground
Basil Uthuppu1 and Mogens Havsteen Jakobsen2
Abstract
2,6-Dichlorobenzamide (BAM) is a degradation product of the herbicide, Dichlobenil that has been used
extensively in Denmark in the past. BAM is not degradable anymore and is soluble in water. Studies show
that this potential ground water pollutant exceeds its allowed maximum limit of 0,1 µg/L in 7,9 % samples
collected in Denmark.
This project aims to develop a biosensor that works on a competitive immunoassay between immobilized
BAM and BAM present in the sample with anti-BAM monoclonal antibody. Here the pre-incubated mixture
of sample and HRP-labelled anti-BAM monoclonal antibody is passed through the BAM-OA-AQ coated
surface and the bound antibody-HRP conjugate is detected by passing TMB substrate into the system
through redox reactions with the help of a screen printed electrode array. Conventional Spectrophotometric method also is used as a bench mark. This interdisciplinary project involves the following main tasks.
• Optimization and regeneration of the polymeric surface that develops a hapten library in a three
stage organic synthesis
• Designing a flow system in which the biosensor is incorporated and that can be used for online
monitoring of BAM in wells
• Designing an electrochemical detection system with high signal to noise ratio
This project is co supervised by Jens Aamand, Senior Research Microbiologist, Dept. of Geochemistry, GEUS and Claus Jørgensen, Senior Biologist, Dept. of Environmental Risk Assessment, DHI 1 ([email protected]) , DTU - Nanotech, Ørsted Plads, Building No. 345 Ø, 2800 Kgs Lyngby. 2 ([email protected]) , DTU - Nanotech, Ørsted Plads, Building No. 345 Ø, 2800 Kgs Lyngby.
Application of X-band and C-band weather radar technology for forecasting precipitation
over urban areas.
Michael R. Rasmussen1 and Søren Thorndahl2
Abstract
As a part of the Storm- and Wastewater Informatics (SWI) project funded by the strategic research council,
an integrated forecast system is developed to predict precipitation over urban areas. The overall aims of the
SWI project are to close the knowledge gaps within prediction and control of current and future conditions in
integrated urban wastewater systems. The major outputs of the project are components of an intelligent real-
time decision support system, following a drop of water from the cloud, throughout the sewer–wastewater
treatment system and into the receiving waters. A precise estimate of precipitation is necessary in order to
model runoff in storm drainage systems. Knowing the precipitation intensity and distribution with a certain
lead time, is also a key prerequisite for real-time control. The research presented here is focused on the radar
based prediction of precipitation using long range C-bands radars combined with short range – high
resolution X-band radars.
Example of COTREC prediction algorithm based on C-band radar
The objective is to analyse the movement and dynamics of precipitation and use that to do a forecast with a lead time of up to 2 hours. However, before this is possible, an adjustment of the radars is necessary. Experience from operational use of the system indicates that a dynamic adjustment strategy is required in order to achieve accurate results. An online system is now available and under test. Information on weather radar research will be available from January 2010 on: www.vejrradar.dk 1 ([email protected] ), Aalborg University, Department of Civil Engineering, Sohngaardsholmsvej 57, 9000 Aalborg, Denmark. 2 ([email protected] ), Aalborg University, Department of Civil Engineering, Sohngaardsholmsvej 57, 9000 Aalborg, Denmark.
Taste of drinking water as a function of aquifer geochemistry and land use.
Helle Marcussen1, Wender L.P. Bredie2, Sandra S. Nielsen2, Walter Brüsch3, Peter E. Holm and Hans Chr. B. Hansen1
Abstract
Water with a high sensory quality has been considered as water free from off-flavours. Much of the research
in the area of water quality has therefore mainly been concerned with understanding and solving problems
related to off-flavours. The relationships between chemical composition and sensory properties, however,
have been difficult to establish. Non-scientific tasting guides suggest mouthfeel as the most important factor
when selecting a bottled water and taste which is related to the content of minerals as the second most
important (Mascha, 2006). Previous studies have mainly focussed on the profiling of the chemical
composition of water and to a much lesser degree the sensory characterisation. The taste of water has been
found to decrease with increasing total dissolved solids (TDS) with 450 mg/l as the limit for good tasting
water (Bruvold and Daniels, 1990).
To investigate the taste of drinking water as a function of aquifer geochemistry and land use, drinking water samples were collected at 20 waterworks distributed over Denmark (Figure 1). The samples represented water extracted from acid to calcitic reservoirs, from sandy reservoirs, to reservoirs under thick clay deposits in costal or inland areas with land use ranging from heather, bog, forest or agriculture. A trained 11-membered sensory panel performed a descriptive analysis of the water samples including descriptors for tastes, odours and oral tactile sensations. The sensory analysis was carried out in sensory booths and included four replicate assessments for each sample using a balanced presentation design. The chemical analysis included pH, conductivity, total hardness, total dissolved solids and non-volatile organic carbon. The total content of Na, Mg, Al, P, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Cs, Ba and Pb was determined by inductively coupled plasma mass spectroscopy (ICP-MS). The content of Cl-, F-, NO -
3 , NO2 and SO4 were determined
by ion chromatography. The total content of solutes was negatively correlated to the perceived freshness, bitter and sour tastes, and positively correlated to salty taste. Salty taste was related to the Na+ and Cl- content possibly due to marine leakage into the costal reservoirs. The sensory differentiation between the inland reservoirs was shown to be relatively small, however, many of them provided water with a high freshness and relatively low intensity of tastes.
Figure 1. Map over Denmark with sampling sites.
References:
Bruvold WH, Daniels JI 1990. American Water Works Association Journal. 82(2): 59-65.
Mascha M 2006. Fine Waters. A connoisseur's guide to the world's most distinctive bottled waters. Quirk Books,
Philadelphia, 190 pp.
1 Department of Basic Sciences and Environment, University of Copenhagen.
2 Department of Food Science, University of Copenhagen.
3 Geological Survey of Denmark and Greenland.
Session 6: Water and Agriculture
Leaching of pathogens from manure to drainage water – assayed using classic and
DNA/mRNA based methods
L. Fredslund1, T.B. Bech1, A. Forslund2, R. Garcia1,4 M. Amin3, J. Baelum1, J. Kjaer1, O. Popovic2, T. X. Bui5, D.D.
Bang5, S. Pedersen3, L.S. Jensen2, M. Laegdsmand3, P. Santorum4, & A. Dalsgaard2 & C.S. Jacobsen1&2
Abstract
The usual practice of addition of animal manure to soil can provide opportunity for contamination of soil
and drainage waters. In a large multidisciplinary project involving many institutions the spread of different
pathogens in agricultural soils has been assayed. In this study, we examined different pathogens using
different techniques to evaluate the survival of the organism in soils: Plate/plaque counting, direct
quantification of mRNA and DNA-based qPCR.
In one experiment of the survival of Salmonella spp., three different factors were tested: temperature, soil type and manure treatment. A tetracycline-resistant Salmonella typhimurium culture was inoculated to yield 107 cfu/g into agricultural topsoil (with or without applied manure) or soil from the B horizon (below plough layer). Soils were stored at 5, 15 and 25ºC simulating seasonal temperature exposure. The survival of Salmonella spp. assayed by plating techniques showed a superior survival at low temperatures, but a general decay was found in all samples. A high number of protozoa was found in the manure amended soil corresponding to a fast decay of inoculated Salmonella spp. Quantification of mRNA and DNA directly in the soil and manure samples showed that mRNA was degraded fast in soils at high temperature while mRNA was more stable at 5°C.
In a field experiment strings of manure were added into agricultural soil. During a period of two months, the sections of soils with different distance to the manure string were assayed to obtain information on survival and spread of virus (bacteriophage), faecal indicators (Enterococci, Bacterioides, E. coli) and tetracycline-resistant bacteria. The die-off of the different organisms was quantified showing an extended survival close to the manure-string. Genomic DNA from 400 tetracycline-resistant bacteria was isolated and their phylogenetic relationship was established using 16SrRNA gene sequencing showing that the main tetracycline-resistant bacterial species is E. coli.
Drainage water from the field was collected weekly from spring 2008. During the samplings in 2008, no tetracycline-resistant bacteria were found, but after manure applications in the autumn 2009 tetracycline-resistant bacteria were recovered. Again, a suite of different organisms were quantified, and in the first drainage water sample after manure application we found approximately 100 tetracycline-resistant cfu ml-1. The total number of tetracycline-resistant bacteria in the manure was 1x104 cfu ml-1.
In conclusion, the survival and environmental spread of pathogens and indicator organisms shows that not only the upper soil are impacted by the microorganisms originating from non-processed manure, but also drainage water can contain quite high numbers of the organisms. The results also show that DNA-based quantification of Salmonella spp. yields higher numbers than quantification based on mRNA indicating that mRNA will form a very conservative choice for pathogen quantification in environmental samples.
1 ([email protected]), Geological Survey of Denmark and Greenland, Denmark. 2 University of Copenhagen, Faculty of Life Sciences, Denmark. 3 University of Aarhus, Faculty of Agricultural Sciences, Denmark 4 Centro de Investigacion y Formacion Agrarias. Consejeria de Ganaderia, Agricultura y Pesca de Cantabria. Spain. 5 Technical University of Denmark
New water saving deficit irrigation guidelines for potatoes and tomatoes based on root
signalling.
Christian R. Jensen1, Fulai Liu1, Yaosheng Wang1, Sven-Erik Jacobsen1,
Finn Plauborg2, Mathias N. Andersen2
Abstract
Agriculture is a big spender of fresh water in competition with other sectors of the society. Within the EU-
project SAFIR (www.safir4eu.org) new water saving irrigation strategies was developed based on pot, semi-
field and field experiments with potatoes, fresh tomatoes and processing tomatoes as model plants. The field
irrigation guidelines was developed under temperate, Mediterranean (Greece, Italy) and Continental (Serbia,
China) climatic conditions during summer. The field investigations on processing tomatoes were undertaken
only in the Po valley (North Italy) on fine textured soil. The guidelines are developed under the assumption
that drought adaptation mechanisms of crop plants can be utilised for optimizing water saving irrigation
scheduling. The investigations showed that gradual and partial soil drying implemented by deficit irrigation
(DI) or partial root zone drying (PRD) induced hydraulic and chemical signals from the root system resulting
in partial stomatal closure, increase in photosynthetic water use efficiency, slight reduction in top vegetative
growth. Further PRD irrigation increased N-mineralization causing a stay green effect late in the growing
season. In potatoes and tomatoes the water saving irrigation strategies DI and PRD were able to save about
20-30% of the water used in fully irrigated plants. PRD irrigation increased marketable yield in potatoes
significantly by 15% due to improved size distribution. PRD increased antioxidant content significantly c.
10% in both potatoes and fresh tomatoes. Under high temperature regime fully irrigation should be
undertaken as clear from field observations in tomatoes. For tomatoes fully irrigation for cooling effects
should be undertaken when night/day average temperature >26.5 0C or when air temperature > 40 oC to avoid
flower dropping. The temperature threshold for potatoes is not clear. From three year field experiments drip
irrigation experiments we found that under the phase of establishment both potatoes and tomatoes should be
fully irrigated; however, during the later phases without causing significant yield reduction deficit irrigation
might be applied for:
o From after end of tuber initiation DI or PRD irrigation is applied as 70% of FI. During the
last 14 days of the growth period DI or PRD is applied at 50% of FI.
• Fresh tomatoes
o From 1st truce is developed for two weeks DI is applied as 85-80 % of FI. In the middle
period DI or PRD is applied at 70 % of FI. During the last 14 days of growth period DI or PRD is applied at 50% of FI.
• Processing tomatoes
o From transplanting to fruit setting at 4-5th cluster PRD and DI irrigation threshold for re-
irrigation is when available soil water content, ASWC=0.7 (soil water potential, Ψsoil =-90 kPa). During the late fruit development/ripening stage, from 10% of red fruits, threshold for re-irrigation is for DI when ASWC= 0.5 ( Ψsoil = -185 kPa) and for PRD irrigation when ASWC (dry side) = 0.4 (Ψsoil, dry side = -270 kPa).
Conclusion: From glass house, semi-field and field experiments using sub-surface drip irrigation the following conclusions were drawn: Water saving irrigation treatments can be undertaken without yield decrease in the range from 20-50% of FI during the growing season. Guidelines for potatoes, fresh tomatoes and processing tomatoes are given for the initial, middle and late growth phases. The findings during the SAFIR project might be used for implementing water saving deficit irrigation guidelines for further adaptation to local soil and climatic conditions.
1 Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen,ViVa-Life 2 Department of Agroecology and Environment, Faculty of Agricultural Sciences, University of Aarhus
Alternate partial root-zone drying irrigation – a novel irrigation strategy improves resources
use efficiency and product quality
Fulai Liu1,*, Yaosheng Wang1, Sven-Erik Jacobsen1, Christian R. Jensen1, Mathias N. Andersen2, Finn Plauborg2
Abstract
Worldwide shortage of freshwater resources has stimulated research into water-saving irrigation strategies in
order to increase crop water use efficiency (WUE). At the same time, global energy crisis and environmental
degradation call for more efficient use of nitrogen (N) fertilizers in crop production due to its high energy
consumption and potential risk to environmental pollution. Alternate partial root-zone drying irrigation
(PRD) is a novel water-saving irrigation strategy being intensively researched in many courtiers. The
principle behind PRD is to alternately let one part of the root system be exposed to soil drying, while the
other part is irrigated, in order to keep the leaves hydrated. The drying roots trigger hormonal signals mainly
abscisic acid (ABA) that induces partially closing of stomata and modifying growth and thereby improving
WUE. PRD irrigation has shown great potential in saving irrigation water in several crop species. Our own
studies at Danish conditions found that, compared with the fully irrigated controls (FI), PRD could save 30%
water without yield reduction in potatoes. Most interestingly, the irrigation technique could enhance crop
nitrogen uptake and improve tuber quality in terms of increased yield of marketable tubers (15%) and
antioxidants content (10%) in the tubers. In tomatoes, we also observed that, compared to FI and common
deficit irrigation (DI) treatments, PRD irrigation could increase WUE (20%), nitrogen uptake (15%), and
fruit quality (e.g. higher antioxidants contents (7%), soluble solids content (10%), and total reducing sugars
content (12%)). By using 15N isotope labelling technique, we have recently demonstrated that the improved
nitrogen uptake under PRD irrigation was due mainly to an enhanced soil mineralisation rate leading to
greater nitrogen availability to the plants. Conclusively, PRD is a promising irrigation strategy that may
simultaneously improve water and N use efficiency as well as product quality in crop plants.
1 ([email protected]), Hoejbakkegaard Alle' 13,DK-2630 Taastrup, Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen 2 Department of Agroecology and Environment, Faculty of Agricultural Sciences, University of Aarhus
Session 7: Public-private RTD cooperation
The Innovation Consortium "Danish Membrane Bioreactor Technology - MEMBIO"
P.E. Jørgensen1 and G.H. Kristensen
Abstract
Within the Innovation Consortium MEMBIO, work has been done since the beginning of 2008 on the
development of innovative solutions to some of the challenges that still limit the use of so-called MBR
technology for wastewater treatment. The consortium has participation from suppliers and users of waste-
water technology as well as from research and GTS environments. Financing of the consortium comes in part
from The Danish Agency for Science, Technology and Innovation and in part from the participating
industrial partners and the GTS institutes.
Membrane Bio-Reactor (MBR) technology represents a technological leap over traditional biological water
treatment technologies. The technology combines microbiological processes with a separation of dissolved
and suspended components through a membrane barrier. MBR technology results in extremely compact
design compared to traditional technology, combined with a markedly improved effluent quality – both with
respect to pollutants of environmental and potential health concern, and with respect to hygienic quality.
The treated water thus represents a potential resource for water reuse for a wide variety of applications in
both urban an industrial contexts. The market for MBR technology solutions to urban and industrial
wastewater treatment is increasing rapidly, and in light of the many advantages when applying the
technology, it is expected that the technology in the not distant future becomes dominant regarding
microbiological-based environmental technology solutions.
Internationally, there has in recent years been invested massively in the development of MBR technology,
and a number of MBR installations are established both for the treatment of municipal and industrial
wastewater. There are however a number of process technical barriers to be dealt with before the MBR
technology is likely to really take hold as the dominant technology for wastewater treatment. Among the
most significant is the tendency of the membrane to clog ("foule"), as well as increased energy consumption
and higher investment costs as compared to conventional wastewater treatment plants. Despite the fact that
Denmark is traditionally strong in the individual disciplines that needs to be integrated to develop
technological solutions based on the MBR concept, activities in the MBR area has so far been modest.
In this context the overall purpose of the consortium is to support, that the traditionally strong position that
Denmark has had within wastewater technology is continued within the MBR field, so that the MBR
technology is established and anchored at Danish suppliers and users of wastewater technology as well as in
research and GTS environments. The above objectives are ensured by conducting relevant themed tech-
nology projects, where the partners in cooperation, and together with the planned research, build up skills
and develop products for the research, GTS and industrial levels.
The different approaches to the current topic represented by the participating universities, GTS institutes and
commercial enterprises, is a great strength for the consortium's work. As the knowledge and skills of the
partners complement each other, the consortium can manage the entire development process from
identification of basic mechanisms to application of technical solutions. The fact that the consortium is
working across different cultures and with background in various incentives, can also be challenging, for
example in relation to intellectual property rights and confidentiality. Innovation Consortia, however, con-
stitutes a flexible and non-bureaucratic cooperation framework, in which the parties themselves to a very
large extent determine the agreements on cooperation, including the confidentiality of information
exchanged between the parties.
1([email protected]), Agern Allé 5, DK-2970 Hørsholm, Denmark
([email protected]), Agern Allé 5, DK-2970 Hørsholm, Denmark
DNA-baserede værktøjer til problemløsning i vandbranchen
Aaron Saunders1
DNA-baserede værktøjer åbner nye muligheder for at løse problemer og optimere biologiske processer. Disse teknologier er indtil for nylig kun blevet brugt på universiteterne, men Teknologisk Instituts Center for Kemi- og Bioteknik samarbejder nu med industrien om at få dem anvendt i praksis. To cases skal præ-senteres: "Forbedret sporing af kilder til fækal forurening" og "Forbedret diagnostik af problemer med jordsmag i dambrugsfisk". DNA-baseret kildesporing af fækal forurening måler på bakterier, der er specifikke for afføring fra bestemte dyregrupper – fx. mennesker, kvæg og fugle – som ellers ikke kan måles med traditionelle metoder. Dette gør det muligt at hurtigt indkredse mulige kilder til forureningen og metoden er blevet brugt i en række sager i Danmark. DNA-baserede analyser bruges også til at identi-ficere kilden til jordsmag i dambrugsfisk. Resultaterne viser at jordsmag bliver dannet i biofilteret af hidtil ukendte bakterier, som ikke kunne måles med traditionelle metoder. 1 ([email protected]), Center for Kemi of Bioteknik, Teknologisk Institut Kongsvang Alle 29, 8000 Århus C, Danmark
Opgradering af våde regnvandsbassiner for videregående rensning
J. Vollertsen 1og M.C. Juul 2
Abstract
Regnvandet fra by og vej indeholder almindeligvis højere koncentrationer af tungmetal end spildevand og er
ligeledes en væsentlig kilde til bl.a. PAH'er og visse miljøfremmede stoffer. Endvidere udgør fosfor fra
separat regnvand ofte et væsentligt bidrag til eutrofiering af søer og kystnære vande. Tilsammen betyder
dette, at udledning af separat regnvand er en betydelig kilde for belastning af vandmiljøet. Gennem de
seneste år har denne problemstilling ført til, at kommuner og vejmyndigheder har etableret anlæg, der renser
regnvandet før udledning til recipient. Den gængse teknologi herfor er våde regnvandsbassiner – det vil sige
små søer eller damme, hvor naturlige processer nedbringer regnvandets forureningsindhold før udledning.
Rundt omkring i byerne og ved motorvejene ligger der i dag i Danmark hundredvis af sådanne rensebassiner.
Korrekt designet er disse systemer effektive overfor partikler og den forurening der er bundet hertil, mens det
har vist sig at effektiviteten overfor forurening på opløst form er ringe. Dette betyder for eksempel at 20-50%
af tungmetallerne fra by- og vejoverflader slipper ud i recipienten, mens effektiviteten overfor vand-
opløselige stoffer, som fx en række biocider, er endnu ringere. Hertil kommer at opløst stof generelt er mere
mobilt i vandmiljøet, hvor vandlevende organismer eksponeres og risikerer at optage stoffet. Afhængig af det
konkrete stofs egenskaber kan der være tale om akut toksisk påvirkning, eller stoffet kan optages i
organismen og slutteligt ophobes i fødekæden. Alt andet lige er opløst forurening derfor – gram for gram –
mere problematisk end partikelbundet forurening. For at sikre en god økologisk kvalitet i vandmiljøet er der
derfor behov for ikke kun at nedbringe den partikelbundne forurening, men også regnvandets indhold af
opløst forurening.
Projektet har til formål at udvikle metalsaltbaseret fældningsteknologi til opgradering af eksisterende
regnvandsbassiner med henblik på at forbedre fjernelsen af opløst og kolloid forurening. Teknologien gør
brug af metalsaltes evne til at binde, kompleksdanne og udfælde opløste og kolloide stoffer, efter principper
der er velkendte fra såvel behandling af drikkevand som spildevandsrensning.
Projektet strækker sig over 3 år og er i sin første fase. Her etableres forsøgsudstyr og gennemføres ind-
ledende undersøgelser i felten og i laboratoriet. Projektets koncept og resultater af indledende undersøgelser
vil bliver fremlagt.
1([email protected]), Aalborg Universitet, Sohngaardsholmsvej 57, 9000 Aalborg
2 ([email protected]), Silkeborg Forsyning, Tietgensvej 3, 8600 Silkeborg
Detecting organic contamination in water by fluorescense technology
E. Arvin, B. Seredyńska-Sobecka, C.K. Waul1, C. Stedmon2,
R. Boe-Hansen3
Abstract
Even in industrialized countries, contamination of fresh water and marine water by sewage is widespread and
microbial contamination of drinking water and swimming pool water also happens quite often. Generally,
there is a need for early warning of wastewater/faecal pollution. Today's methods are slow (within several
hours or days) whereas response times of seconds or minutes may be required. The Aqua Fingerprint project
aims at developing the knowledge base for future development of fluorescent based sensors that can detect
faecal contamination in "clean" water within seconds. The water types investigated are: drinking water,
swimming pool water, surface water and rain water. Through the use of PARAFAC – parallel factor analysis
– fluorescence spectra (see below) are decomposed into a number of fluorescent components, typically 3-5.
This technology has allowed us to detect levels of raw wastewater in "clean" water of 0.1-0.2 %,
corresponding to 25-50 µg wastewater C/l. The project has shown that there is a potential of detecting faecal
contamination within characteristic times of seconds.
Figure. Fluorescense spectrum of a wastewater sample. 1 ([email protected]; [email protected]; [email protected]), DTU, Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, 2800 Kgs. Lyngby, DK. 2 NERI, Department of Marine Ecology, National Environmental Research Institute, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, DK (E-mail: [email protected]) 3( [email protected]), Krüger A/S, Gladsaxevej 363, 2860 Søborg, DK Acknowledgement: Partly financing of the project is provided by: By- og Landskabsstyrelsen/Miljøministeriet.
Future urban water supply when the groundwater resource is under pressure
H.-J. Albrechtsen1, M. Rygaard and P.J. Binning,
Abstract
Growing populations and urbanization challenge the limits of our conventional water resources in the
developed world. Other more political drivers such as the EU water Framework Directive has with the recent
publication of the ‘Vandplaner' put a tremendous pressure on the water supplies, especially in the Copenhagen area. At this background alternative water resources are considered to be exploited, and an outlook to solutions in other parts of the world shows a wide array of solutions with several options for increasing self-sufficiency. This includes use of unconventional water resources such as centralized wastewater reuse, desalination and local and central rainwater collection. The scientific literature and the internet were searched for projects with increased self-sufficiency of an urban area, and a screening list of 113 cases was compiled including examples from around the world. The collection was intentionally restricted to represent possible solutions, and not every single project encountered, and e.g. many desalination projects were omitted, since they all represented variations of reverse osmosis membrane set-up. Many solutions are already in use around in the world. However, introduction of alternative water resources raises several challenges: Energy requirements vary with more than an order of magnitude among the alternative techniques, wastewater reuse allows trace contaminants to reach the drinking water. Finally changes to the drinking water system can meet tough resistance from the public. This work is based on a Public-Private-Partnership between KE and DTU Environment. Rygaard, M., Binning, P.J. & H.-J. Albrechtsen. (2009) Alternative water management and self-sufficient water supplies, IWA
1 ( [email protected]), Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Bygning 113, DK-2800 Kgs. Lyngby, Denmark
Collaboration between Infarm and Danish universities and knowledge institutions
Jesper Lorenzen 1
Abstract
Infarm is a vendor of environmental technology for intensive animal production. As such, the company
operates in a strictly regulated market, where claims constantly need documentation to have credibility. This
is led the company to collaborate with Danish universities and other knowledge institutions throughout it
R&D history.
From the very early proof-of-concept to the latest complex studies of lifecycle assessment, Infarm has
opened its books for researchers to question, investigate and comment. Ultimately, the result is unequalled
documentation level of the technology's performance and environmental effect as well as excellent
relationships with Danish experts.
All in all, close RTD collaboration requires precise project formulation as well as strict internal and external
project management to create valuable knowledge. When carried out successfully, research collaboration is a
fantastic fruitful experience; when not, it is utterly frustrating.
1([email protected]), Infarm A/S and Grundfos New Business, Poul Due Jensens Vej 7, DK-8850 Bjerringbro
The ScorePP approach to predict releases of priority pollutants from urban sources
H.-C. Holten Lützhøft1, E. Eriksson1, E. Donner2, T. Wickman3, P. Banovec4, P.S. Mikkelsen1, A. Ledin1
Abstract
The priority substances included in the EU Water Framework Directive shall in the course of 20 years obey
environmental quality standards set for EU watercourses. The substances classified as hazardous substances
shall furthermore be phased out of discharges. The aim of this study was to compile knowledge about the
releases from point, diffuse and accidental sources to urban pollution of these priority pollutants (PPs) to be
able to reduce or cease the emissions of said PPs. The Emission String (ES) concept was developed, which
identifies an emission source by the particular pollutant being emitted (CAS #), the (economic) activity
resulting in the emission (NACE), and the specific emission process (NOSE) during which the pollutant
release takes place, all of which are connected to an Urban Structure descriptor, a Release Pattern descriptor
and a Release Factor.
This classification approach was tested on a range of PPs listed in the WFD. Not a wealth of release factors
connected to these sources could be found in the open literature, thus data like emission loads were also
compiled. Of the 902 ESs established only 154 ESs were associated with release factors. No data were found
for 578 ESs. Data on loads were established for 118 ESs, leaving 54 ESs assigned various information. In
relation to the urban structure descriptor the majority of the ESs are related to manufacturing or production
facilities, but other large source categories are households, waste disposal activities, transport, construction
and agriculture, of which many can be classified as diffuse sources. Analysing the data on road transport it is
seen that seven PPs are released due to vehicular combustion and wear and tear processes. Dependent on the
substance and the activity or process, the releases account for between the low kg range for nickel and up to
hundreds of tonnes for benzene.
1 ([email protected]), DTU Environment, Miljøvej 113, DK-2800 Kgs. Lyngby, Denmark
1 ([email protected]), DTU Environment, Miljøvej 113, DK-2800 Kgs. Lyngby, Denmark
2 ([email protected]), University of South Australia, Mawson Lakes Campus, Adelaide, Australia
3 ([email protected]), Stockholm Stad. Fleminggatan 4, 10420 Stockholm, Sweden
4 ([email protected]), University of Ljubljana, Jamova 2, 1000 Ljubljana, Slovenia
1 ([email protected]), DTU Environment, Miljøvej 113, DK-2800 Kgs. Lyngby, Denmark
1 ([email protected]), DTU Environment Miljøvej 113, DK-2800 Kgs. Lyngby, Denmark
Coupling of numeric water quality models to quantitative microbial risk assessment - the
future for assessment of the burden of disease caused by human contact with water.
Frank Leck Fotel1, Mads Joakim Birkeland, Gerald Heinicke, Anders Erichsen, and Claus Jørgensen
Abstract
One of the most prevalent causes to human illness remains the exposure to faecal contamination via water. In
developing countries, poor sanitation still causes a high mortality, especially among children. In developed
countries, good sanitary conditions have been achieved through sewerage, but the population is still exposed
to faecal contamination through drinking water, recreational water and through other contacts to
contaminated surface water.
With climate change, a more frequent contact with contaminated water is expected because of more frequent
flooding events. During a flooding event, the sewage system may not be able to hold the large volumes of
water - the water will flood streets and basements. Additionally untreated water will enter recreational water
bodies. Therefore, new routes of exposure to treated or untreated sewage appear and may cause severe
illness. In this project we will model the risk of primary infection during flooding events by linking the
hydraulic models that predict the extent of the flooding to Quantitative Microbial Risk Assessment (QMRA). It is the intention that the QMRA shall be compatible with the Mike models in general in order to extend the applicability of the model.
1 DHI, Agern Allé 5, DK-2970 Hørsholm, Denmark
Spatial Externalities – The Implications for Optimal Design of Pollution Reduction Targets
Maria Theresia Hedegaard Konrad1, Sisse Liv Brodersen, Kris Munch and Berit Hasler
Abstract
The discharge of nitrogen and phosphorous from several countries to the Baltic Sea causes serious water
quality problems with respect to eutrophication and oxygen deficits. The Baltic Sea Action Plan (BSAP)
proposed by HELCOM (2007) is an attempt to address this. It is common practice in environmental policies
to set targets for reduction of emissions (Hart and Brady, 2002) often with a predefined allocation of
reduction targets between relevant agents, such as countries. However, the environmental effects depend on
the location of emissions and are not necessarily restricted to the area in which they are emitted. This paper
addresses the implications for policy target-setting when such spatial externalities exist. Pollution reductions
in the Baltic Sea are used as a case study.
Two different approaches to pollution reduction targets for the Baltic Sea are evaluated, i) targets set on the environmental quality in the individual sea-regions of the Baltic Sea, ii) targets set on nutrient load reduction targets for individual countries emitting pollutants into the Baltic Sea. The approaches are evaluated in terms of the total costs and environmental quality taking into account the spatial transfer of pollutants between sea regions.
A non-linear cost-minimization model for the Baltic Sea is set up, embracing all sea regions and countries around the sea. Data from all the riparian countries are used. The model is used to prescribe abatement activities to obtain the different reduction targets. Not only the nutrient discharges to the sea from land, but also the effect on environmental quality due to transportation of nutrients via sea flow between the sea-regions is accounted for. The results show that obtaining a good ecological quality in all sea-regions is much harder than immediately recognized, since some sea-regions are very exposed due to transportation of nutrients.
The research illustrates the importance of accounting for both economic and environmental heterogeneity in policy evaluations as the seemingly harmless difference between the two sets of targets has important implications for the spatial distribution of externalities. The results are compared and contrasted to the extensive literature on spatial externalities from airborne emissions, such as the literature on sulphur dioxide in the U.S. The case study suggests that this type of research has important implications for policy evaluations related to the Water Framework Directive and the Marine Strategy Directive.
References. Gren, I.-M., 2000. Cost-effective nutrient reductions to the Baltic Sea. In: Gren, I.-M., Turner, K., Gren, I.-M., Wulff, F., 2004. Cost-effective nutrient reductions to coupled heterogeneous marine water basins: An application to the Baltic Sea. Reg Environ Change (2004) 4:159–168. Gren, I.-M. et al, 2008. Costs of nutrient reductions to the Baltic Sea - technical report. Swedish University of Agricultural Sciences, Working Paper Series 2008:1. Hart, R. and Brady, M. 2002, Nitrogen in the Baltic Sea- Policy Implications of Stock Effects. Journal of Environmental Management (2002) 66:91-103. HELCOM 2007. HELCOM Baltic Sea Action Plan. HELCOM Ministerial Meeting, Poland 2007 Wulff, F. (Eds.), Managing a Sea—The Ecological Economics of the Baltic. Earthscan Publications Ltd., London Schou, J.S., Neye, S.T., Lundhede, T., Martinsen, L., Hasler, B. 2006, Modelling Cost-Efficient Reductions of Nutrient Loads to the Baltic Sea, National Environmental Research Institute. Stavins, R. N. Experience with Market-Based Environmental Policy Instruments, Chapter 9 in: Handbook of Environmental Economics, vol.1 (2003). Tietenberg, T. Tradable Permits for Pollution Control when Emission Location Matters: What have We Learned?
Environmental and Resource Economics (1995) 5:95-113. 1 ([email protected]), Aarhus University, National Environmental Research Institute, Department of Policy Analysis, Frederiksborgvej 399, Postbox 358, DK 4000 Roskilde
Freshwater discharge, 1990-2008.
- Assessment of freshwater discharge to coastal waters round Denmark using a meta DKQ-
model combining measured and DK-model estimated discharge.
Jørgen Windolf 1, Brian Kronvang1, Lars Troldborg 2, Hans Jørgen Henriksen 2
Abstract
A new harmonised modelling tool (DKQ) has been developed for the estimation of monthly freshwater
runoff to coastal waters around Denmark for the period 1990-2008.
DKQ is based on results from 179 gauging stations covering 57% of the ca. 43,100 km Danish land area in a
combination with modelled runoff for ungauged coastal areas utilising the DK-model. For 99 of the gauging
stations unbroken time series of measurements are available for the period 1990-2008. However, for 80 of
the gauging stations there's no unbroken time series of daily discharge measurements. Hence, at technique
for both interpolation and extrapolation has been developed to generate estimated station specific monthly
runoff in periods with no measurements. This technique use a combination of measured monthly runoff from
reference gauging stations in coastal catchments and modelled monthly runoff for specific catchments
lacking an unbroken time series of measurements. The modelled runoff is derived from the MIKE SHE
model (DK-model), where results from 1 km×1 km grid's has been available at the time of meta model
development. The modelled runoff was shown to have general station specific bias as well as seasonal bias
when comparing model estimates with measurements. Station specific model corrections for these bias's
have been made and the adjusted modelled runoff has then been used for periods with no measurements from
the 80 stations. For periods with no modelled runoff available (2006-2008), results from a set of reference
gauging stations holding full time series of measurement have been used in the inter- and extrapolation
procedures.
For land areas being ungauged areas in the period 1990-2008 (43% of the Danish land area) the DKQ meta-
model utilises monthly empirical relationships developed between a set of reference gauging stations and the
DK-modelled monthly runoff for 320 smaller ungauged coastal watersheds. Hence, within each of nine
major Georegions bias correction factors have been calculated as the average ratio between observed
monthly runoff at the gauging stations and the monthly runoff simulated with the DK-model for the same
gauging stations. These bias correction factors have been applied for the ungauged coastal watersheds lying
within each Georegion. For periods with no modelled runoff (period 2006-2008) results from a set of
reference gauging stations holding full time series of measurement have been used for extrapolation. Hence,
each coastal watershed is linked to one or several reference gauging stations and empirical monthly
relationships between simulated and bias corrected monthly runoff as calculated with the DK-model for the
ungauged area within the coastal watershed and the reference station(s) have been developed. These monthly
relationships are then utilised to calculate the runoff from the ungauged part of the coastal watershed after
having accessed to the monthly runoff data from the reference station.
The DKQ meta model described above has been developed in a NOVANA project collaboration between the
National Geological Survey of Denmark (GEUS) and the National Environmental Research Institute (NERI),
Århus University. Experiences gained will be used in the ongoing updating of the hydrological DK-model
(www.vandmodel.dk). The discharges estimated by the procedure described have been used in the reporting
of results from the national environmental monitoring programme including calculations of nutrient loadings
to coastal waters.
1 ( [email protected]), Department of Freshwater Ecology, National Environmental Research Institute (NERI), University of
Aarhus
2 Geological Survey of Denmark and Greenland (GEUS)
Nitrogen retention
- Assessment of nitrogen retention of nitrogen leached from soil towards the coastal waters,
1990-2008. National end regional figures and trends.
Jørgen Windolf1, Gitte Blicher-Mathiesen & Brian Kronvang
Abstract
Although landbased Nitrogen loadings to the coastal waters have been markedly reduced since the 1990'ies
these loadings still impacts the environmental quality of the Danish fjords and near coastal waters. The main
source of this loading is nitrate leaching from the root-zone below the grown fields. Other minor sources are
nitrate leaching from unfarmed areas and nitrogen outlets of sewage to freshwaters or directly to the coastal
waters.
However, during the hydrological cycle a substantial part of these nitrogen outlets are retained. Thus, mean
annual Nitrogen leaching from the rootzone can be estimated to 212.000 t N (1990-2008). However, mean
diffuse Nitrogen loading to coastal waters was only 67.300 t N during the same period. Hence, Nitrogen
retention – by difference – was 145.000 t N or 68% of the estimated leaching. 121.000 t N of this retention is
estimated to be due to nitrate reduction in ground waters - the remaining 24.000 t N being retained in
surface waters. The major sinks for nitrogen in surface waters are assumed to be lakes (8.400 t N) and the
streams themselves (15.100 t N).
The geographical variation in Nitrogen retention is substantial and proper assessment of these varying
retentions in different catchments is important when estimating the effect of measures applied to reduce the
nitrate leaching.
On a national scale a GIS based map of the varying retention is available for estimating the local/regional
effects of changes in nitrogen leaching. For catchment with measured figures for Nitrogen load in streams
the retention is calculated by difference between Nitrogen leaching and measured Nitrogen loading in the
stream. However for catchment with no measured N load in streams, estimation of Nitrogen retention is
performed using a retention model. This model is regionally validated on results from 19 streams on the
island of Fyn by comparing the simulated and measured nitrogen load in the stream. For these streams
regional empirical models has previously been developed linking the annual nitrogen leaching from the root
zone and the nitrogen loading in the streams by a simple nitrogen reduction model. Furthermore, a new
model for estimating nitrogen concentrations in streams has recently been developed (DK_NP). One of the
driving forces (variables) in this model is the annual surplus of nitrogen in Danish agriculture and the
development in this surplus. For the national figures there are a strong relationship between this surplus and
the Nitrogen leaching from the agricultural land. The goodness of fit of these 3 models will be evaluated and
the implications discussed.
1( [email protected]), Department of Freshwater Ecology, National Environmental Research Institute, University of Århus.
Comparison of statistical downscaling procedures for assessing climate change impacts on
water resources at catchment scale
Henrik Madsen1, Keiko Yamagata, Maria A. Sunyer, Torsten V. Jacobsen
Abstract
It is well known that climate projections from global circulation models (GCM) are biased and cannot
adequately reproduce the variability in climate variables that are present at the local scale. Thus, there is a
need for downscaling climate projections from GCMs in order to make reliable impact assessments at the
local scale. Regional climate models (RCM) that are set up for a particular region and nested within a GCM
are able to resolve the atmospheric processes on a finer scale and better account for complex topographical
features and land cover heterogeneities. However, RCM inherits the biases and other deficiencies of the
GCM, and hence further downscaling is often needed for RCM projections.
Statistical downscaling has been introduced to relate the climate projections at larger scale (from GCMs or RCMs) to climate variables at the local scale. In this paper downscaling of RCM projections is considered for water resources impact assessment at catchment scale. Different downscaling procedures based on a general change factor methodology are applied and compared. The basic concept in change factor methods is that climate model simulations are used to extract changes in different statistical characteristics of climate variables from the present to the future climate (denoted change factors). These changes are then superimposed on the statistical characteristics of the climate variable representing the local scale, which are subsequently used for the impact assessment. The paper considers climate change impacts on the water resources in the North-Eastern part of Sealand, Denmark. Climate simulations from the HIRHAM RCM for the period 1950-2100 based on the IPCC SRES scenario A1B are used in the analysis. Three different downscaling procedures are applied to downscale precipitation, temperature and potential evapotranspiration. These include: (i) mean correction (often referred to as the delta change method), (ii) mean and variance correction, and (iii) a stochastic weather generator based on the Neyman-Scott rectangular pulse model. The downscaled climate data are used as forcing to a MIKE SHE integrated hydrological model of the region for analysing the impacts of climate change in relation to (i) regional and sub-catchment water balance components, (ii) droughts and low flow conditions, and (iii) high flows and flooding. 1([email protected]), DHI, Agern Allé 5, DK-2970 Hørsholm, Denmark
Source: http://www.danishwaterforum.dk/research/Proceedings/Proceedings%20DWRP_2010.pdf
Boron Compounds in the Breast Cancer Cells Chemoprevention and Chemotherapy Ion Romulus Scorei Biochemistry Department, University of Craiova, Craiova, Dolj, 1. Introduction Various biological functions of Boron (B) compounds are known (Blevins & Lukaszewski, 1994; Tariq & Mott, 2007; Nielsen, 2008). Boron is found in nuts, vegetables, dried/fresh fruits and red wine (Brown & Shelp, 1997). Boron is also present in bacterial antibiotics, such as tartrolon, borophycin, boromycin and aplasmomycin (Rezanka & Sigler, 2008); in the bacterial quorum sensing molecule auto-inducer AI-2 (Bemd et al., 2002); and in vibrioferrin, a B-containing siderophore produced by particular marine bacteria (Shady et al., 2007). In plants, the rigidity of the cell wall depends on the rhamnogalacturonan II complex (RG-II) formation, a pectic polysaccharide covalently linked by cis-diol bonds to apiosil residues of borate-esters (Ishii & Matsunaga, 1996, 2001). Several articles have provided information about transporters responsible for efficient B uptake by roots, xylem loading and B distribution among leaves. The transporters are required under B limitation for efficient acquisition and utilisation of B. Two types of transporters are involved in these processes: NIPs (nodulin-26-like intrinsic proteins) for boric acid channels and boron exporters encoded by BOR1 (Miwa & Fujiwara, 2010). The expression of the genes encoding these transporters has been shown to be finely regulated in the B availability response to ensure tissue B homeostasis. Furthermore, the tolerance of plants to the stress produced by low B or high B in the environment can be generated by altering the expression of these transporters (Tanaka & Fujiwara, 2007). All of these transporters are involved in boron transport regulation in plants. B is an essential element not only for vascular plants but also for diatoms, cyanobacteria and a number of marine algal flagellate species (Rezanka & Sigler, 2008). Recently, ATR1 has been found to be responsible for the high B tolerance in S. Cerevisiae. ATR1 encodes a multidrug resistance transporter and it is widely distributed in bacteria, archaea and lower eukaryotes (Miwa & Fujiwara, 2010). Animals such as zebra, fish, trout and frogs also require boron (Rowe & Eckert, 1999; Fort et al., 1999). Borate ions activate the mitogen-activated protein kinases pathway and stimulate the growth and the proliferation of human embryonic kidney 293 cells (Park et al., 2005). The B-transporter, NaBCl, controls plasma borate levels in human kidney cells (Park at al., 2004). The fact that B has such a broad range of physiological functions is not surprising. The electron structure of B and its position in the periodic table (adjacent to carbon) make B-containing molecules electrophilic with the trigonal
Clinical and Laboratory StudiesFreeStyle™ Blood GlucoseTest Strip Performance Executive Summary 2.0 FreeStyle Overview . . . . . . . . . 2 Objective:To evaluate the performance of the Abbott FreeStyle blood glucose test strip for accuracy, precision, 2.1 Coulometry Technology . . . . . . . . 2 linearity, interference, hematocrit effect, and ease of use.