Abstract:
Mechanism of drought disaster in karst areas is complex, and the technical specification method of drought disaster risk census does not consider the drought disaster mechanism comprehensively, resulting in insufficient coordination between the drought disaster risk zoning results with the county-level administrative regions as the assessment unit and the historical drought disaster results, which has become a difficult problem in the drought disaster risk census in Guizhou Province. As the basic theory of drought disaster risk zoning, the natural disaster risk theory constructs a drought disaster risk zoning index system with karst characteristics based on the natural disaster risk theory to conduct drought disaster risk research, which can provide a basis for drought disaster risk zoning. Taking Zunyi City as an example and based on risk theory of natural disasters, the representative indicators of drought disaster risk in karst area are analyzed and selected, a drought risk zoning model is established, the weight of drought disaster index system is determined by coupled weighting method of expert scoring method and entropy weight, and quantile classification using ArcGIS, and drought disaster risk zoning research is carried out.(1)The results show that surface water drought hazard index, terrain composite index, cultivated area and proportion of drylands, rural centralized water supply rate and effective farmland irrigation ratio are the main influencing factors of the drought hazard, environmental vulnerability, exposure of the values at risk, and capacity to prevent or mitigate drought disaster, respectively.(2)The drought disaster risk level of all counties and districts in Zunyi City is mainly medium risk or below, accounting for 64.3%, and the cumulative proportion of medium-high risk areas and high-risk areas are 35.7%.(3)The overall drought disaster risk shows a pattern of high distribution in the northeast and low in the southwest and regional distribution characteristics. High-risk areas are distributed in the northeast, medium-high risk areas are distributed in the north, medium-risk areas are distributed in the east, medium-low risk areas are distributed in the south, and low-risk areas are mainly distributed in the middle. Through a comparative analysis with the national drought relief program and other related data, the rationality of the zoning results is verified, which can provide a scientific basis for the local drought disaster prevention work.