Evaluation of Near-Real Time Drought Forecasting Using VIC and SWAT Models in the Contiguous U.S.

Track 3A: Forecasting Droughts and Floods
Thursday, October 12, 2017, 3:40 pm – 5:10 pm

Hyunwoo Kang and Venkat Sridhar
Department of Biological Systems Engineering
Virginia Tech

Short-term drought forecasting is an essential component to establish drought mitigation plans and risk managements of water resource systems. In this study, Soil and Water Assessment Tool (SWAT) and Variable Infiltration Capacity (VIC) models are used for short-term drought forecasting (weekly) in the Contiguous U.S. Weekly to seasonal meteorological inputs are provided by Climate Forecasting System version 2 (CFS v2), and they are used to estimate the hydrological, agricultural, and groundwater drought conditions. The daily streamflow is calibrated by using SWAT calibration and uncertainty program for SWAT and Shuffled Complex Evolution (SCE-UA) Method for VIC at multiple locations in the Contiguous U.S. for the historic period between 1970-Present. For drought assessment, various drought indices which include Standardized Soil Moisture index (SSI), Multivariate Standardized Drought Index (MSDI), and Palmer Drought Severity Index (PDSI) will be analyzed. Additionally, probabilistic distributions and Bayesian averaging techniques will be explored to assess the uncertainty.