Identification and evolution characteristics of drought field in the Pearl River Basin based on REOF-ESMD

Abstract The traditional drought field studies are inadequate to study characteristics from the perspective of trend and periodicity at same time, especially compare interannual interdecadal variations different types in reveal their similarity difference patterns. Pearl River Basin (PRB) was determined this paper using standardized precipitation evapotranspiration index (SPEI) empirical orthogonal function (EOF)/rotated (REOF). Periodic features were recognized by extreme-point symmetric mode decomposition (ESMD) other methods. results showed that regional five spatial modes may be used categorize PRB; there cycles associated with southwest-type northwest-type drought. central-south-, north-central- eastern-type droughts had both cycles; during period, PRB's revealed a changing tendency as opposed straightforward linear trend; variation, consistent prior 2000, north-central-type before 2010.