국내 가뭄관리 기관별 PDSI 산정방법의 표준화 및 평가

Abstract

The objective of this study is to standardize the calculation method of PalmerDrought Severity Index (PDSI) for the three Drought Management Agencies (DMA) in southKorea, and to evaluate the PDSI applicability. For comparison and review of the method, thecode and input data of PDSI are collected from each DMA. The calculation method is thesame, but the used input data (number of meteorological stations, normal year period, AvailableWater Capacity (AWC) of the soil) are different. Through discussions with drought expertsand literature review, the standardized method is determined. 61 stations which have the dataperiod more than 30 years are selected. Also the normal year is fixed for 30 years and updatedevery 10 years. The observed AWC is utilized using GIS data. Empirical equation of PDSI isre-estimated according to domestic climate characteristics. For evaluating the standardizedPDSI, past drought events are investigated and drought indices including the existing SPI andPDSI are used for comparative analysis. As results, although the accuracy of standardizedPDSI through ROC analysis is lower than SPI, the newly standardized PDSI is better thanexisting PDSI from DMA, Also it reasonably explain the spatial drought situation through thespatial analysis.