Climate, land cover and land use are changing, thereby imposing changes to the hydrological cycle which are affecting the access to water resources and increasing the frequency of extreme hydrological events, such as floods and droughts. In order to predict future freshwater availability and the vulnerability of ecosystems and society to floods and droughts, hydrological model tools are needed that are capable of accurately representing climate, land use and land cover at different spatial scales.
The purpose of the current project is to develop model tools capable of quantifying the relative effects of site-specific land use change and climate variability at different scales.
Evaluating impacts of site-specific changes in land use and land cover on catchment processes is significantly complicated by spatial heterogeneity and the long and variable time lags between precipitation and the responses of soil, streams and groundwater. To address the research objectives, new data- and model- based technologies will be combined. This includes the use of a Distributed Temperature System (DTS) for measuring spatial variations in stream temperature. The DTS system uses a long (1-2 km) fiber-optic cable to provide temperature measurements with 1 meter resolution. The system will be used to identify and model lateral inflows to the stream in relation to the spatial characteristics of the upland contributing land areas which are represented as multiple (cumulative) sub-catchments. At the larger scales (all Sjælland), Earth observations will be used for land surface hydrology modeling, and effective land surface representation schemes will be developed. Impact of effective spatial land surface hydrology representation will be analyzed and verified using new satellite based atmospheric sounders (AIRS, IASI) which are providing high vertical resolution information of atmospheric properties (ie. air temperature, air humidity and CO2). For this purpose the land surface scheme will be used in a next-generation regional climate model. The impact of land surface hydrology and heterogeneity on the atmospheric boundary layer development will then be analyzed and verified using the (3-D) observed variations in atmospheric condition from AIRS and IASI.