ESA space sensor boosts extreme weather forecasting
The European Space Agency (ESA) has made public the first soil moisture maps of the southern African subcontinent. The maps have a spatial resolution of one kilometre. Based on information from ESA's Envisat satellite, the maps are expected to help scientists better predict extreme weather conditions such as floods and droughts. 'Predicting when and where floods are likely to happen is becoming more and more important,' says researcher Geoff Pegram from the University of KwaZulu-Natal in South Africa. 'Although we cannot prevent floods, we can anticipate them and hopefully get people out of the way. This brings hydrology into the 21st Century and makes life better for people,' he added. Water stored in soil is important for both agricultural planning and weather forecasting. When there is too little soil moisture, crops and vegetation wilt. When there is too much, the risk of extreme weather, such as flash floods and erosion, increases. Despite the importance of this type of information, there has been a lack of soil moisture information in Africa because of the high costs of taking measurements on location. In addition, unlike satellite observations, point-based measurements are often not sufficient to provide an overall picture of large areas that may be effectively used in models. The ESA-backed project, SHARE (Soil Moisture for Hydrometeorological Applications in the Southern African Development Community Region), is the first to demonstrate that space sensor instruments can deliver soil moisture data, which are accurate to one kilometre and less than a week old. Researchers have already used the technology to predict extreme weather conditions in Asia. 'Chinese scientists have used our data to initialise weather forecasts and demonstrated they could better predict the location and intensity of a precipitation event, which resulted in a flood,' said Wolfgang Wagner from the Vienna University of Technology. 'Soil moisture is such an important variable that it influences vegetation, soil, run-off and weather, affecting the lives of us all.' Dr Wagner added.