Climatological Drought Analyses and Projection Using SPI and PDSI: Case Study of the Arkansas Red River Basin

Abstract

This paper examines past drought and assesses future drought scenarios for the Arkansas Red River Basin using two common drought indexes, the Standardized Precipitation Index (SPI) and Palmer Drought Severity Index (PDSI). Historical climate data within the 1900–2009 time frame were used to derive the past drought index estimates. The projected climate data under two greenhouse gas emission scenarios from 16 global climate models (GCMs) after bias correction and statistical downscaling were applied in drought occurrence frequency and affected area projection. The results derived from the SPI and PDSI show that widespread droughts mainly took place in the 1910s, 1930s, 1950s, and 1960s in the Arkansas Red River Basin, which agrees well with the historical climate record. Both the SPI and PDSI project that more frequent and severe droughts will appear in the second part of the 21st century under both of the emissions scenarios. Future PDSI projects that more severe droughts will occur in the western parts of this basin under one scenario.