Onderzoeksproject SR/00/100 (Onderzoeksactie SR)
Context and objectives
The rationale of this project is the increasing need for improved tools supporting water management at the catchment level as required by different national and international legislations. In 2000, the Water Framework Directive has been introduced in Europe which set the political frame for implementing Integrated Water Management (IWM) at the catchment level. The European Commission is currently also preparing a directive on the assessment and management of floods. This new directive will aim at the reduction and the management of the risks that floods pose on human health, the environment, and the infrastructure. As it is foreseen that in the coming decades the risk for flooding will be higher, and the economic damage will increase appropriate measures are needed that can reduce its likelihood, or limit its impacts. These measures should be based on a thorough understanding of the impact of management measures on the hydrologic and hydraulic functioning of catchments.
The overall goals of this project are 1) to explore new strategies to integrate radar remote sensing, hydrologic, and hydraulic modelling for water management purposes through data assimilation, and 2) to demonstrate the applicability of advanced data assimilation schemes for a set of water management problems. The major outcome will be fundamental knowledge about radar data assimilation in hydrology. The major deliverables will be a set of data and operational procedures supporting water management.
Methodology
• A combination of advanced hydro-geophysical techniques, focusing on Ground Penetrating Radar (GPR), which will be optimised, and integrated for fast and high resolution soil moisture measurements;
• Retrieval of soil moisture changes and mapping of flooded areas based on time series of radar imagery;
• A new approach, based on possibility theory, for the retrieval of soil moisture from Synthetic Aperture Radar (SAR) data, will be developed;
• In order to better understand the relationship between ground- and satellite-based radar data, scaling properties of soil moisture will be studied using GPR and SAR derived soil moisture maps;
• A hydrologic and a hydraulic model will be coupled;
• Several data assimilation schemes will be implemented and further developed in order to allow an improved modelling of the rainfall-runoff relationship and the prediction of flood extents.
Results expected
The results expected include:
• an improved methodology for determining soil moisture at the microscale, based on the GPR-technique;
• algorithms for retrieving soil moisture and flooded areas from time series of multipolarized data;
• soil moisture retrieval accounting for uncertainty in roughness parameters;
• an improved understanding of the spatial scaling behaviour of soil moisture;
• development of a coupled hydrologic/hydraulic model with implementation of several data assimiliation schemes;
• demonstrations to different applications of the model.
