SRES B2情景下西南地区干旱致灾危险性时空格局预估

Projecting Spatio-temporal Patterns of Drought Hazard in Southwest China under SRES B2 Scenario

气候变化和自然灾害已经、正在、未来也将继续深刻地影响人类社会。预估未来极端天气事件致灾危险性对于评估气候变化对人类社会和自然系统的潜在风险具有极其重要的意义。本研究采用PRECIS模式模拟的气候情景数据,综合考虑降水和蒸发两个因素,选取地表湿润指数为指标,对SRES B2情景下未来(2011-2100)西南地区县域尺度干旱致灾危险性时空格局进行预估。结果表明:相对于现阶段(1981-2010),未来西南地区年均潜在蒸散量呈现逐渐增加的趋势,而地表湿润指数则总体上呈减小之势;未来各时段西南地区旱灾危险性明显增大,其中近期(2011-2040)是最严重的时段;在近期时段,西南地区干旱致灾危险性处于5级的县域个数和面积百分比分别为236个和50.3%,是现阶段的4.82倍和6.24倍。

Climate change and natural disasters have a continuous impact on human society profoundly. Projection of hazard changes in climate extremes is critical to assess the potential impacts of climate change on human society and natural systems. Using simulations of ＇Providing Regional Climates for Impacts Studies＇ , surface humid index （precipitation/potential evapotranspiration） was selected to project the spatial patterns of drought hazard in Southwest China at county scale for the present （1981 -2010） and future （2011 - 2100） under SRES B2 scenario. The results showed that compared with the present period, the mean annual potential evapotranspiration in Southwest China would increase in the future, while the mean annual surface humid index would decrease. The drought hazard in the future would be more serious, especially in the near-term （2011 -2040）. The number of counties in grade five of drought hazard would be 236 and the area percentage would be 50.3% in the near-term, 3.82 and 5.24 times more than present period respectively. The results can provide scientific basis for drought risk management under climate change in this area.