A New Agricultural Drought Disaster Risk Assessment Framework: Coupled a Copula Function to Select Return Periods and the Jensen Model to Calculate Yield Loss

China is one of the regions with most frequent drought disasters and serious social economic losses. Agricultural natural disaster. Due to climate change, regional agricultural risk assessment has always been focus academic circle. This study takes Zunyi City as an example, which typical city karst landform development. The monthly precipitation data set ground meteorological observation stations in from 1956 2020 was selected, characteristic variables were extracted by coupled use anomaly percentage (Pa) index theory runs. A copula function applied establish joint distribution model variables, obtaining frequency return periods. Combined Jensen model, loss rate under different periods target year (2020) calculated evaluated. results showed that Gumbel-Hougaard suitable for City. From 2020, fewer droughts occurred Zhengan Wuchuan, took place Fenggang, Meitan, Yuqing. average duration each county about 1.5 months, severity 0.35 spatial distribution. Crop caused increased affected area expanded increase (5, 10, 20, 50, 100 years) temporal Meanwhile, disaster drastic eastern region, followed south, north, west, central area. highly consistent historical City, verified validity model. could provide scientific knowledge resistance reasonable mitigation programing security production sustainability