Evaluation of Hydrologic Estimates and Extremes from the NASA South Asia Land Data Assimilation System

Two consecutive heat waves during 2015-16 and associated drought in India made international news headlines in recent times. These hydro-climatic extremes aggravate underlying water and land resource issues that are having severe societal consequences, as seen in sharpened class conflicts and, in extreme cases, farmers' suicides.  The South Asia Land Data Assimilation System (South Asia LDAS) has been developed to achieve better estimates of land-surface state and flux variables for the South Asian countries and to enhance information-based decision making in the face of tightening water resources and extreme events. Evaluation of South Asia LDAS, however, is a challenge due to limited data collection and public sharing of available data. Here, we present (1) the results of novel satellite-based model evaluation, including streamflow and latent heat flux, (2) the results of South Asia LDAS applications to the 2015-16 temperature extremes and droughts and (3)  the use of satellite altimetry as an alternate for gauging network for ungauged rivers and for remote areas.