Development of an experimental near-real time drought monitor for India

Abstract

Persistent and wide spread drought hampers water resources management and crop production. India has been facing droughts frequently since the last few decades. Despite detrimental impacts of droughts in India, a real-time monitoring system at appropriate spatial and temporal resolution has been lacking. Here we develop an experimental drought monitor for India, which operates daily at spatial resolution of 0.25 degree and provides near-real time information on drought. The real-time daily precipitation data are obtained from the Tropical Rainfall Measurement Mission (TRMM), while daily temperatures are obtained from the Global Ensemble Forecast System Analysis (GEFS) reforecast version 2. Near-real time precipitation and temperatures are bias corrected using the historic precipitation and temperature data from the Indian Meteorology Department (IMD). We reconstructed data extending from past to near present by combining IMD (1969-2010) with real-time bias-corrected TRMM and GEFS datasets (2010 onwards). The experimental drought monitor provides information on meteorological, hydrological, and agricultural droughts using Standardized Precipitation Index (SPI), Standardized Runoff Index (SRI), and Standardized Soil Moisture Index (SSI), respectively. Soil moisture and runoff are simulated using the Variable Infiltration Capacity (VIC) model in near-real time to estimate severity and areal extent of agricultural and hydrological droughts. Areal extent and severity of droughts from the Experimental Drought Monitor are successfully evaluated against satellite based drought severity index. The experimental drought monitor provides high resolution drought information (district level) which can be valuable for natural resources management and policy making.