Use of satellite remote sensing to evaluate an integrated global land surface hydrology - routing - water resources management model

An integrated model has been developed to advance our understanding of the interactions between human activities, terrestrial system and water cycle, and to evaluate how system interactions will be affected by a changing climate at the regional and global scales. The integrated model consists of a land surface hydrology model (LSM) with crop and irrigation modules, a routing model and a water resources management model (WM). The modeling system has shown reasonable performance at the regional and subregional scales over the Columbia River Basin and Upper Midwest in the USA. The overall and individual components of integrated system were validated by evaluating both regulated and natural flows, reservoir storage and water supply with respect to observations. In this presentation, the first application of this system at the global scale is discussed. The overall system is evaluated with respect to GRDC observed regulated flow. The terrestrial hydrologic simulations are evaluated against GRACE and MODIS products, and data-model or observed naturalized flow where available. In addition, the reservoir model is evaluated with respect to satellite altimetry data from the US Department of Agriculture and French Space Agency (Centre National D'Etudes Spatial CNES). Although the reservoir model is not tuned specifically for each observed regulated flow, we investigate potential bias and discuss on the cascade of errors from the atmospheric model forcing, into the LSM down to WM over major reservoirs throughout the world for different hydro-climatic conditions and reservoir characteristics.