MODIS 위성영상 기반 ESI와 ROC 분석을 이용한 가뭄위험평가

초록

Drought events are not clear when those start and end compared with other natural disasters. Because drought events have different timing and severityof damage depending on the region, various studies are being conducted using satellite images to identify regional drought occurrence differences. Inthis study, we investigated the applicability of drought assessment using the Evaporative Stress Index (ESI) based on Moderate Resolution ImagingSpectroradiometer (MODIS) satellite images. The ESI is an indicator of agricultural drought that describes anomalies in actual and referenceevapotranspiration (ET) ratios that are retrieved using remotely sensed inputs of Land Surface Temperature (LST) and Leaf Area Index (LAI). However,these approaches have a limited spatial resolution when mapping detailed vegetation stress caused by drought, and drought hazard in the actual cropcultivation areas due to the small crop cultivation in South Korea. For these reasons, the development of a drought index that provides detailed higherresolution ESI, a 500 m resolution image is essential to improve the country’s drought monitoring capabilities. The newly calculated ESI was verifiedthrough the existing 5 km resolution ESI and historical records for drought impacts. This study evaluates the performance of the recently developed500 m resolution ESI for severe and extreme drought events that occurred in South Korea in 2001, 2009, 2014, and 2017. As a result, t he two E S Isshowed high correlation and tendency using Receiver Operating Characteristics (ROC) analysis. In addition, it will provide the necessary informationon the spatial resolution to evaluate regional drought hazard assessment and and the small-scale cultivation area across South Korea.

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