全球变暖引发的极端气候事件及其对人类社会的影响一直备受瞩目。以纬向地带性较明显的陕西省为研究对象,利用水文、气象、人口（POP）、国民生产总值（GDP）空间分布数据以及基础地理信息数据,采用统计分析法、三参数幂函数法、K-S检验及空间分析等方法,结合《陕西省暴雨洪涝灾害风险分析系统》探究了该地区五级流域的降水致洪的空间分异及承载体暴露特征,并研究分析不同降水情景下各五级流域致洪重现期分布情况。结果表明：（1） 陕西省在大雨情景时,洪水的分布特征呈现出南少北多的状态;在暴雨情景下洪水的分布呈现出中部与西南部较轻。（2） 重现期临界面雨量的等值区域分布趋近于等高线分布,且等值线极值呈现上升趋势。（3） 不同重现期承载体暴露度在中低风险区呈下降趋势,在高风险和极高风险区呈上升趋势,10 a一遇重现期暴露量呈现先快后慢的上升特征,100 a一遇重现期呈现先慢后快的上升趋势。本文基于陕西省五级流域,依据地理空间分析并结合灾害系统的结构体系,为分析降水致洪的空间分异规律提供了新的探索,对陕西省防灾减灾及流域治理工作提供决策支撑。

Extreme climate events caused by global warming and their impact on human lives have been comprehensively explored. One of these events is flooding, which has a very complex occurrence mechanism. Rainfall and underlying surface factors, including vegetation, landform, and soil, are closely related with the occurrence of flood. Among them, rainfall is the consequential external force factor that causes floods. In the fifth-grade river basins in Shaanxi Province in the hinterland of mainland China, numerous short-duration, strong-intensity local rainstorms are observed in summer. Therefore, the main flooding type in this province is induced by rainstorms. In this study, Shaanxi Province, which has obvious zonality, was considered as the research object. The spatial differentiation of rainfall-induced flooding and carrier exposure characteristics of the five-level basins in the region was explored through hydrology, meteorology, POP, GDP, basic geographic information data analysis, statistical analysis, three-parameter power function method, K-S test, spatial analysis, and other methods combined with “Shaanxi Province Rainstorm and Flood Disaster Risk Analysis System”. The distribution of flood-induced return periods was analyzed in each five-level basin under different precipitation scenarios. ArcGIS spatial analysis method was used to examine the spatial differentiation patterns of flooding caused by a decrease in water levels under different scenarios in the fifth-grade watersheds of Shaanxi Province. Based on this, the spatial and temporal characteristics of flooding induced by precipitation in this region were evaluated, and the exposure of the disaster-bearing body in the study area was discussed. The prediction and early warning and disaster prediction assessment of precipitation-induced flooding were conducted in the study area to create a layout of human social, economic, and agricultural activities and provide scientific basis for disaster prevention and mitigation. The results show that (1) the distribution of floods in Shaanxi Province under heavy rain scenarios is low in the south and high in the north. The distribution of floods in central and southwestern regions is lower. (2) The regional distribution of the critical surface rainfall during the return period is close to contour distribution, and the extreme value of the contour increases. (3) Upward and downward trends of carrier exposures in different return periods are observed in low- and medium-risk areas and high-risk and extremely high-risk areas, respectively. The once-in-a-ten-year return period exposure first increases rapidly and subsequently increases gradually. The upward trend ten during the once-in-a-hundred-year return period occurs slowly at first and rapidly thereafter.