Distinguished Lecture - HS

Venkataraman LAKSHMI
University of Virginia

Tue- 30 Jul, 12:00-12:30pm
Nicoll 3, Level 3

"Observing the Terrestrial Water Cycle from Space"

Abstract
Land surface hydrology is a collection of complex processes. Precipitation is partitioned into infiltration and runoff depending on antecedent soil moisture conditions, the properties of the soil, the slope of the land surface and the atmospheric demand for evapotranspiration. The spatial variability both the land surface properties (soil and vegetation) as well as the meteorological inputs (precipitation and radiation) play an important role in hydrology. Land surface hydrology is heterogeneous in space and time - making observation and modeling activities very difficult. Satellite remote sensing has a broad spatial view of the land surface and is able to provide data for use in hydrology such as soil moisture, surface temperature and vegetation density. Satellite sensors include - microwave observations for soil moisture and precipitation; visible/near infrared for vegetation and evapotranspiration, gravity for groundwater/total water and thermal observations for surface temperature. Soil moisture is a key variable in hydrology. However, the spatial resolution of soil moisture observations is on the order of 10km and this is very coarse for catchment hydrological applications. In this talk I will discuss an innovative method for downscaling soil moisture to 1km and its validation with ground and aircraft observations at a regional scale and high spatial resolution soil moisture for the continental United States. I will show how the satellite observations and model outputs can be used to close the water budget for continental river basins. From a societal context, satellite observations are instrumental in determining the available water resources in regions of the world where observations are lacking and local economy is tied closely to water.

Biography
Professor Venkataraman Lakshmi graduated from University of Roorkee in 1987 with a Bachelor degree in Civil Engineering and a Doctorate in Civil and Environmental Engineering in 1996 from Princeton. He worked at NASA Goddard Space Flight Center 1996-1999 as a research scientist in the Laboratory for the Atmospheres. His areas of interest are catchment hydrology, satellite data validation and assimilation, field experiments, land-atmosphere interactions, satellite data downscaling, vadose zone and water resources. He served as the Carolina Trustee Professor and former Chair of the Department of Earth and Ocean Sciences at the University of South Carolina (1999-2018) and is currently Professor in the Department of Engineering Systems and the Environment at the University of Virginia. Venkat has over 80 peer-reviewed articles and 300 presentations and thesis supervisor for 25 graduate students. He is currently is serving as Associate Editor of Journal of Hydrology and editor for Vadose Zone Journal and former chairman of the Chapman Conference committee for AGU and the founding editor-in-chief of Remote Sensing in Earth System Science (Springer Journals). He has served as Cox Visiting Professor at Stanford University 2006-2007 and 2015-2016 and Program Director for Hydrologic Sciences at the National Science Foundation (2017-2018). He has served on the National Academies Panel for the Decadal Survey of Earth Observations from Space (NASA) and as chair of the planning committee for Groundwater Recharge and Flow: Approaches and Challenges for Monitoring and Modeling Using Remotely Sensed Data (NGA).