RCPs情景下贵州省干旱趋势分析

Drought trend analysis under RCPs scenariosin Guizhou Province

为探究贵州省未来干旱变化趋势,基于CMIP5全球气候模式预估的降水月值数据,利用标准化降水指数(SPI)分析了2016—2050年RCPs情景下贵州省干旱趋势。结果表明:2016—2050年间RCP2. 6、RCP4. 5和RCP8. 5情景下贵州省SPI指数均呈现增加趋势。除特旱外,RCP8. 5情景下轻旱、中旱、重旱发生频次高于RCP2. 6和RCP4. 5情景。2016—2030年各情景下各干旱等级发生频次较高。不同情景下各干旱等级的干旱频率空间异质性突出。各情景下贵州省干旱站次比和干旱强度均呈现下降趋势,发生全域性干旱年份较多,发生区域性干旱和局域性干旱年份较少。发生轻度干旱强度年份较多,发生中度干旱强度和重度干旱强度年份较少。RCPs情景下贵州省降水增加导致干旱风险降低。研究结果可为干旱监测和农业生产提供参考依据。

In order to explore the drought change trend in the future,the drought trend in Guizhou Province from 2016 to 2050 under RCPs scenarios is analyzed by the method of standardized precipitation index(SPI)based on forecast data of monthly precipitation of CMIP5 global climate model.The result shows that the SPI index of RCP2.6,RCP4.5 and RCP8.5 scenarios from 2016 to 2050 is increased.The frequency of light drought,moderate drought and heavy drought under RCP8.5 scenario are higher than RCP2.6 and RCP4.5 scenarios except for the excessive drought year.The frequency of each drought level under RCPs scenarios from 2016 to 2030 is relative higher.The spatial heterogeneity of drought frequency for each drought level under different scenarios is significant.Under the different RCPs scenarios,the drought station ratio and drought intensity shows a decreasing trend.The year of large-scale drought is more than the regional-scale and local-scale drought,and the year of light drought intensity is more than the moderate and heavy drought intensity.The increasing of precipitation under RCPs scenarios in Guizhou Province results in a decreasing trend of drought risk.The results can provide a reference for the drought monitoring and agricultural production work.