Evaluating Land Information System (LIS) capabilities in simulating the water budget and surface water dynamics over data-scarce areas in the Middle East

Despite recent advances in land surface modeling and remote sensing, estimates of the global water budget are still fairly uncertain. Uncertainties are particularly high in areas where data for model calibration and evaluation are scarce or unavailable. This study presents recent developments in the hydrological modeling over the Tigris-Euphrates River basin. An intercomparison effort is performed in order to determine how models and meteorological forcings represent physical processes. In this sense, multiple experiments are performed using state-of-the-art capabilities implemented in the NASA Land Information System (LIS). The NASA Modern Era Retrospective Reanalysis for Applications (MERRA) and Global Data Assimilation System (GDAS) meteorological datasets are used as main forcings. Additional experiments are performed replacing their precipitation with the Climate Hazards Group Infra-Red Precipitation with Stations (CHIRPS) dataset. Both Catchment and Noah land surface models coupled with the Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme are considered to simulate the water budget and surface water dynamics. Due to the scarce ground-based data availability, satellite-based estimates of the terrestrial water storage, evapotranspiration, water level and floodplain extent are used as complimentary information to evaluate the hydrological behavior in the basin. In particular, the water shortage observed in 2015 in that region is analyzed based on model outputs. Finally, we discuss prospects and challenges in considering anthropogenic impacts (irrigation and dams) on the hydrological modeling of the basin.