Water Budget Estimation Using In-situ and Remote Sensing Products in the Chesapeake Bay Watershed

Track 2A: Understanding the Water Budget
Thursday, October 12, 2017, 2:00 pm – 3:10 pm

Venkat Sridhar
Department of Biological Systems Engineering
Virginia Tech

Gridded observation, in-situ, and remote sensing products that provide information regarding water budget components are used to estimate seasonal and annual variations of water storage at Chesapeake Bay watershed for the period of 2001-2016. The gridded observation (Parameter-elevation Regressions on Independent Slopes Model, PRISM) and Variable Infiltration Capacity (VIC) model-based evapotranspiration and soil moisture estimates are compared with remotely sensed components (Global Precipitation Measurement, GPM and Soil Moisture Active Passive, SMAP). The spatial distribution of the VIC model-based change in terrestrial water storage estimates agree with the Gravity Recovery and Climate Experiment (GRACE)-based distribution. The distribution shows increased water storage in the southeastern region and decreased water storage in the northwestern sections of the watershed. The magnitude, however, varies seasonally due to the overestimation of streamflow in the summer months. Despite the seasonal differences, the annual mean of the change in water storage by the VIC model (-0.11 mm) is close to GRACE estimates (-0.34 mm). Contributing authors: Mirza Billah – Post-doctoral Researcher, Biological Systems Engineering at Virginia Tech. Bin Fang- Post-doctoral Research, Columbia University. Venkat Lakshmi – Carolina Trustee Professor, School of Earth Ocean and the Environment, University of South Carolina.