Development of satellite-based Surface water stress index considering surface water balance

The IPCC presented accelerated climate change and an increase in abnormal climate phenomena in the 21st century. This abnormal climate increases the frequency and intensity of extreme precipitation, resulting in changes in the water balance, such as precipitation and evaporation. Droughts are caused by prolonged water shortages, and it usually occurs in areas with subaverage rainfall. Drought is difficult to point precisely at the start and end, so its monitoring and forecasting are important to prepare for damage and mitigate impact. And although various satellite-based drought indices are being developed and used, it is still difficult to define drought quantitatively and to select a drought index suitable for the local situation. Currently, the drought indices used in Republic of Korea include SPI, which deals only with the water supply, and SPEI using the simple difference between precipitation and evapotranspiration. However, no standardized system of drought monitoring suitable for agricultural drought situations, such as the supply, consumption and impact of vegetation, has been established. However, it does not have a standardized system for monitoring drought agricultural drought suitable for situations such as the supply and demand of water and the impact on vegetation. this study tried to shows a new drought index that best expresses the drought in Korean cropland using long-term satellite data.