极端气候事件对我国旱灾适应性的影响机制研究

Based on the disaster system theory, taking the extreme weather events as the hazard-inducing factors, aiming at the spatial-temporal characteristics of drought disasters in China, the five typical drought areas were choosen that were progressive drought areas in the Southwest China, the arid areas in the Northwest China, higher temperature and summer drought area in the middle and lower reaches of the Yangtze River Basin, environmental fragile area between Agriculture and Pasture in North China, drought-flood abrupt alternation area of Hunan Province, Hubei Province and Jiangxi Province. With the historical major drought disaster cases data, based on "regional differences of disaster pregnant environment", effect of extreme weather events in different regions on household adaptation was studied. Based on "household losses at different stages", effect of extreme weather events in different stages on household adaptation was exploered. Based on "different household income", the effect of extreme weather events on household of different income was studied. Field investigation was developed aiming at validate different results, effect mechemics of the extreme weather events on drought disaster risk and adaptation was studied. Drought adaptation model of "Different regions-different stages- different types" was pur forward. It may provide a scientific base and decision support for early warning of drought disaster risk and adatpation countermeasures in China.

本研究基于灾害系统理论，引入极端气候事件作为致灾因子的突变因素，针对我国旱灾发生的时空特征，选取西南山地连年干旱区、西北内陆常年干旱区、长江中下游高温伏旱区、农牧交错带干旱生态脆弱区、湘鄂赣旱涝急转频发区等五个旱灾发生典型区，结合历史重大旱灾案例的灾情数据，在"分区孕灾环境差异"的基础上，以极端气候事件作为突变致灾因子，探讨不同区域极端气候事件对农户适应性的影响机制；在"分时农户损失差异"的基础上，揭示农户受极端气候事件不同影响阶段适应性的变化规律；在"分类农户收入差异"的基础上，研究不同收入水平农户对极端气候事件的适应性差异；针对不同结果开展野外实证分析，依据极端气候事件对旱灾风险评估及适应性机制研究，提出"分区-分时-分类"的旱灾适应模式，为我国旱灾风险防范和制定适应对策提供了重要的科学依据和决策支持。

本研究基于灾害系统理论，引入极端气候事件作为致灾因子的突变因素，针对我国旱灾发生的时空特征，选取西南山地连年干旱区、西北内陆常年干旱区、长江中下游高温伏旱区、农牧交错带干旱生态脆弱区、湘鄂赣旱涝急转频发区等五个旱灾发生典型区，结合历史重大旱灾案例的灾情数据，在“分区孕灾环境差异”的基础上，以极端气候事件作为突变致灾因子，探讨不同区域极端气候事件对农户适应性的影响机制；结果显示，中国西南喀斯特地区玉米受旱减产的风险呈现从西北到东南增加的趋势，在4 种风险水平（2、5、10、20 年一遇）下，面积占比最大的产量损失率主要集中分布在0.4～0.5 区间内，这主要由地形地势、降水差异和承灾体的脆弱性所共同决定的；受石漠化影响，土层厚度为40 cm 时，4 种风险水平对应的减产率分别为5.8%、6.1%、7.8%、8.2%；针对不同结果开展野外实证分析，依据极端气候事件对旱灾风险评估及适应性机制研究，提出了“分区-分时-分类”的旱灾适应模式，为我国旱灾风险防范和制定适应对策提供了重要的科学依据和决策支持。