Multi-Sensor Multi-Satellite Remote Sensing of Drought Analysis with Multi-Sectoral Impacts and Multi-Scale Vulnerability in Thailand

Drought monitoring and assessment is critical considering the immense costs and impacts Thailand has been experiencing these days.  Deficit in precipitation is typically referred to as meteorological drought.  While deficit in soil moisture (i.e., below average moisture in the soil) is known as agricultural drought.  Hydrological drought corresponds to a deficit in runoff or groundwater resources. Socio-economic drought (also known as anthropogenic drought) refers to water stress intensified by human activities and increase water demands.  Our long-term research in ground observation drought monitoring and assessment has been integrated with remotely sensed precipitation and soil moisture information necessary for the computation of extensively used drought indicators, such as Standardized Precipitation Index (SPI) using widely available satellite-based precipitation products including PERSIANN, TRMM, GSMaP, and IMERG to demonstrate the multidimensional and multi-sectoral impacts of change in rainfall patterns which is directly linked to drought assessment.  Long-term satellite-based soil moisture time series obtained from NASA’s Soil Moisture Active Passive (SMAP) mission have been employed for drought detection from provided near real-time top soil moisture estimates in accordance with The Gravity Recover and Climate Experiment (GRACE) mission.  Preliminary results indicate that multi-sensor multi-satellite remotely sensing data can enhance soil moisture mapping and its long-term spatial and temporal trends match well with change in terrestrial water storage and groundwater storage of the country.   This approach can provide more robust and integrated measure of drought based on wider range of satellite observations such as precipitation, soil moisture, total water storage anomalies, groundwater storage change, offering the opportunities to investigate droughts from different viewpoints. Drought monitoring scheme developed in this work can serve as a supporting tool for water resources and climate change policy making.  It can contribute to improve understanding on potential impacts of climate change, multi-sectoral linkages, multi-scale vulnerability, and adaptation programs.