The European Space Agency (ESA) and the World Meteorological Organization conclude the second Space for Hydrology workshop today in Geneva. A group of scientists from 27 countries agree that while great progress has been made on space-based hydrological observations, more innovations are needed.
Over the past 20 years, remote sensing techniques have gained great capacity to observe and assess the world’s water resources and forecast water-related disasters such as floods and droughts. Satellite sensors can now locate water bodies and delineate river networks, and can quantify water-related variables such as precipitation, soil wetness, water levels and water storage. They can also monitor the water balance of large river basins on time scales ranging from weeks to years, quantifying spatial parameters relevant for hydrological models and providing real-time information for flood forecasting.
However, the information is insufficient for developing countries and many areas of the world aren’t currently monitored. Crucial information about the world’s water resources are missing, and these observations are needed in order to adequately measure freshwater resources, which are crucial for human life.
ESAâ€™s ERS and Envisat satellites and the NASA-CNES Topex-Poseidon and Jason satellites, provide surface water levels (oceans, lakes, reservoirs, rivers, wetlands and floodplains) and space gravity missions, like ESAâ€™s GOCE and NASAâ€™s GRACE, provide estimates of the variations of terrestrial water storage (in soils, lakes, reservoirs and groundwater) in space and time. These observations from space have the potential to improve significantly our understanding of hydrological processes affecting large river basins in response to climate variability and change.