Characterizing hydrological hazards and trends with the NASA South Asia Land Data Assimilation System

Friday, 18 December 2015
Poster Hall (Moscone South)
Debjani Ghatak1, Benjamin F Zaitchik2, Ashutosh S Limaye3, Nancy D Searby4, Bradley Doorn5, John D Bolten6, David L Toll6, Sylvia Lee7, Bessma Mourad7, Kapil Narula8, Shilpa Nischal8, Charles Iceland9, Birendra Bajracharya10, Sujay Kumar6, Basanta Raj Shrestha10, MSR Murthy11, Christopher Hain12 and Martha C. Anderson13, (1)Johns Hopkins University, Applied Physics, Baltimore, MD, United States, (2)Johns Hopkins University, Baltimore, MD, United States, (3)NASA Marshall Space Flight Center, Huntsville, AL, United States, (4)NASA Headquarters, Washington, DC, United States, (5)NASA Headquarters, Earth Science Directorate, Washington, DC, United States, (6)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (7)Skoll Global Threats Fund, San Francisco, CA, United States, (8)Confederation of Indian Industry, New Delhi, India, (9)World Resources Institute, Washington, DC, United States, (10)ICIMOD, Kathmandu, Nepal, (11)International Centre for Integrated Mountain Development (ICIMOD), Kathmandu, Nepal, (12)Earth System Science Interdisciplinary Center, COLLEGE PARK, MD, United States, (13)USDA ARS, Pendleton, OR, United States
South Asia faces severe challenges to meet the need of water for agricultural, domestic and industrial purposes while coping with the threats posed by climate and land use/cover changes on regional hydrology. South Asia is also characterized by extreme climate contrasts, remote and poorly-monitored headwaters regions, and large uncertainties in estimates of consumptive water withdrawals. Here, we present results from the South Asia Land Data Assimilation System (South Asia LDAS) that apply multiple simulations involving different combination of forcing datasets, land surface models, and satellite-derived parameter datasets to characterize the distributed water balance of the subcontinent. The South Asia LDAS ensemble of simulations provides a range of uncertainty associated with model products. The system includes customized irrigation schemes to capture water use and HYMAP streamflow routing for application to floods. This presentation focuses on two key application areas for South Asia LDAS: the representation of extreme floods in transboundary rivers, and the estimate of water use in irrigated agriculture. We show that South Asia LDAS captures important features of both phenomena, address opportunities and barriers for the use of South Asia LDAS in decision support, and review uncertainties and limitations.This work is being performed by an interdisciplinary team of scientists and decision makers, to ensure that the modeling system meets the needs of decision makers at national and regional levels.