Study On The Driving Mechanism Of Hydrologic Drought In Karst Basin Based On Landform Index: A Case Study of Guizhou, China

Abstract. In recent years, hydrological droughts in the Karst Basins have become more frequent and have caused serious ecological and environmental problems. This paper took the karst drainage basin of Guizhou, China as the study area to analyze the geomorphologic distribution and the temporal-spatial variations of hydrological droughts. The results indicated that (1) the rainfall and its variation during drought periods had very limited impacts on the hydrological droughts in karst drainage basins; (2) During 2000–2010, the hydrological droughts in Guizhou Province increased year by year, and the inter-annual variation of hydrological droughts in Guizhou had obvious stage characteristics. The overall regional distribution of hydrological drought severity in Guizhou is severe in the south and light in the north, severe in the west and light in the east. (3) From the overall distribution of the landform types, the mountains, hills and basins have a certain impact on hydrologic droughts, but the impacts are insignificant. From the distribution of single landform types, the influences on hydrological droughts are particularly significant in high-medium mountains, deep-high hills and high basins, and where are also relatively light areas for hydrologic drought severity, While the relatively serious areas of that in the low mountains, shallow-low hills and low basins.