Annual Report 2006
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Water resources |
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The effect of climate change
on the water cycle
In 2006, GEUS calculated the impact of climate change on the freshwater cycle in Denmark for the Danish Environmental Protection Agency. These calculations were carried out for two climate scenarios from the Danish Meteorological Institute using the so-called DK model developed by GEUS. It is the first time that the signals from the climate models have been integrated with the national hydrological model, which is able to describe in detail how climate change affects the entire water cycle - geographically, at different depths, and in relation to time. The calculations reveal a significant impact on the water cycle in Denmark, with large regional and seasonal variations. For example, the model shows that available water resources will increase in west Jutland, and that there should be no problem covering future water requirements if they remain the same as today. However, the calculations also suggest that river valleys and lowlying areas will suffer from lack of water for large parts of the year, with a resulting detrimental effect on agriculture. In Zealand, the most severe effect of climate change will be a marked prolongation of the period with low run-off in the water courses. The purpose of the study has been to quantify the future groundwater recharge, the determination of the groundwater level, the groundwater pressure in the deeper-lying reservoirs, as well as watercourse run-off. All are important parameters for good, future management of water resources and the aquatic environment, and interest in the work with the model has consequently been substantial. Toward the end of the year, GEUS commenced a similar survey which incorporated landuse and sea-level rise for the Danish Water and Waste Water Association (DANVA) and the Copenhagen-based utilities company, Københavns Energi. |
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Sustainable water abstraction of
deep groundwater in the limestone
Due to the percolation of polluting substances, we can anticipate increasing problems with the water quality in many water wells in north-east Zealand, where water abstraction is from the uppermost jointed limestone strata. In recent years, there have thus been attempts at finding deeper and better protected groundwater resources in the limestone. In some places, the search has been successful, but in others, problems with saltwater in the wells have been a stumbling block. In 2006, GEUS completed a project stretching over several years, which has provided knowl - edge about the possibilities for water abstraction from the deep - er strata of the limestone without influencing the stability of the interface between freshwater and the underlying salt water. The project mapped the depth and characteristics of the saltwater/ freshwater interface and examined the processes that de - fine the location of the interface. The results identify areas in northeast Zealand with particularly favourable conditions for ab stracting the deep groundwater in a sustainable manner. The results also outlined the processes that influence the assessment of the temporal development of the salt loading of wells. Further - more, the project has contributed new knowledge about the suit - ability of different methods for mapping the saltwater/freshwater interface and provides recommendations on how best to organise drilling surveys to map the interface. The project was carried out with Environment & Resources at the Technical University of Denmark and was funded by Københavns Energi, Copenhagen, Roskilde and Frederiksborg counties. |
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Oestrogen run-offs from
liquid manure into
the aquatic environment
For many years, we have known that the application of liquid manure to fields can lead to the negative addition of nutrients to the aquatic environment; however, no survey has been made to clarify wheth - er hormone substances in livestock manure may also have a negative impact. Sows and hogs naturally produce the sex hormone oestrogen, which is se - cre ted through manure. In the past, the belief was that oestrogens were either bound to the soil or degraded. In 2006, GEUS presented new results which show that oestrogens from manure can run off into the aquatic environment. In two trial fields with moraine clay in Jutland, liquid manure was applied as part of normal farming operations. In both fields, measurements later showed that oestrogens run off into the aquatic environment in concentrations that may lead to hermaphroditism in fish. Up to three or seven months after application of the manure, oestrogens were still found in high concentrations in the drainage water from the fields. This is the first time, under actual field conditions, that it has been demonstrated that application of liquid manure could be a possible source of pollution of the aquatic environment with hormone substances. The work was carried out in collaboration with the Faculty of Agricultural Sciences at the University of Aarhus and the Faculty of Life Sciences at the University of Copenhagen. |
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New tools for
managing water resources
The EU Water Framework Directive sets out requirements for overall management of water resources that caters for groundwater, surface water and e.g. socio-economic aspects. Hydrological models linking groundwater and surface water are used in resource management, and there is increasing demand for quality assurance of the use of these models. In 2006, the GEUS-run EU project HarmoniRiB was completed. This project has developed methods to assess the uncertainty of water data and models. The results are available at the website of the project: www.harmonirib.com. Here you can find e.g. the software tool DUE, which helps users describe and assess the uncertainty of data. Furthermore, a number of guidelines have been prepared on how to assess uncertainties and incorporate them in decision-making processes in connection with water management. Finally, the project has gathered data containing information on uncertainties in a database from eight representative catchment areas in Europe. The database can be used freely for research purposes, and the project researchers are currently in dialogue with the European Environ - ment Agency on takeover of the database. In September 2006 at a workshop in Brussels, the project results were presented to key persons working with water management in Europe. |
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A map of
pesticide-sensitive sandy soil
The general sensitivity of sandy soil to pesticide leaching can be explained by the soil's content of humus, clay and silt. This is one of the main conclusions of the KUPA project, which GEUS and the Faculty of Agricultural Sciences at the University of Aarhus completed in 2004. The project shows how to calculate sensitivity on the basis of knowledge about the few, simple soil parameters. Since then, the parties involved in the project have carried out a number of de - monstration projects on sandy soil at different locations throughout Denmark. In collaboration with the Jutland counties of Ribe, Aarhus and Northern Jutland, tests were made to ascertain whether it is practicable to identify especially sensitive sandy soil at farm level. Since the data coverage at national level consists of point data, it was necessary to use statistical methods in order to describe the geographical distribution of the soil properties. The tests were successful, and during 2006, GEUS and the Faculty of Agricultural Sciences presented a map of all Danish sites with sandy soil sensitive to pesticide leaching. The map is based on information from different maps of soil-types and soil-conditions and information in the texture database. The basis for the map can be improved e.g. by adding new soil data and interpreting texture conditions relative to topography. |
