江西省山洪灾害时空分布及其驱动因子研究

Temporal-spatial Distribution and Driving Factors of Mountain Torrent Disasters in Jiangxi Province

为研究江西省历史山洪灾害的时空分布特征及其驱动因子,本研究采用标准差椭圆、空间自相关、聚类和异常值分析等空间分析方法以及地理探测器,对江西省山洪灾害调查评价成果中1951-2015年历史山洪灾害数据进行分析;以十年为研究期,选取江西省1996-2005年以及2006-2015年两个近期时段,利用地理探测器分析驱动因子变化格局。结果表明:(1)1951-2015年各年代的山洪灾害重心主要分布在江西中部地区,呈西南-东北格局,历史山洪灾害总体分布随年代向南北方向收缩。(2)江西省东部、中部和东北部形成了过程降雨量高值聚类,县域内山洪灾害数量及平均降雨量呈空间正自相关。(3)降雨是对江西省历史山洪灾害解释力最强的驱动因子类型,其中解释力最高的是最大6 h暴雨均值,降雨因子两两之间呈双线性增强关系;在其他类型的驱动因子中,高程、坡度、地貌类型和土地利用有较高的解释力。(4)最大6 h暴雨均值与其他驱动因子交互后,解释力均大幅提高,与年降雨量因子交互解释力最强。(5)在分时段的驱动因子探测中,降雨和土地利用因子的解释力随时间有所提升,自然地理因子的解释力较为稳定。研究结果为查清江西省山洪灾害时空分布特征及山洪灾害监测预警、风险评价、防治区划等提供坚实的理论基础和科技支撑。

In order to study the spatial and temporal distribution characteristics and driving factors of historical mountain flood disasters in Jiangxi Province,this paper analyses the data of historical mountain flood disasters from 1951 to 2015 in Jiangxi Province by using the methods of standard deviation elliptic,Global Moran’s analysis,Anselin Local Moran’s analysis and geographic detector.Taking ten-year as a period,this paper selects two recent periods(1996-2005 and 2006-2015)to analyze the change pattern of driving factors in Jiangxi Province by using geographic detectors.The main findings are the following:(1)The centers of mountain flood disasters in different decades are mainly distributed in the central part of Jiangxi Province,showing a southwest-northeast pattern,the overall distribution of mountain flood disasters shrinks in the north-south direction with time.(2) The spatial autocorrelation analysis indicates a positive spatial correlation between the amount of mountain-flood disaster and ARD(average rainfall during historical mountain-flood disaster)in rural areas.The cluster of high ARD is formed in the central,east and northeast areas of Jiangxi Province.(3) Of all the driving factors,rainfall has the strongest explanatory power for historical mountain flood disasters in Jiangxi Province,among which the highest explanatory power is the maximum 6-hour average rainstorm,and there is a bilinear enhancement relationship between rainfall factors.Among other driving factors,elevation,slope,landform type and land use have higher explanatory power.(4) After the interaction between the maximum 6-hour average rainstorm and other driving factors,the explanatory power is greatly improved,and the interactive explanatory power with the annual rainfall factor is the highest.(5) In the driving factor detection at different time periods,the explanatory power of rainfall and landuse increase with time,while the explanatory power of natural geographical factors are relatively stable.The results provide a theoretical basis,scientific and technological support for the investigation of the temporal-spatial distribution characteristics of mountain-flood disaster in the Jiangxi Province,which can also benefit the monitoring and early warning,the risk assessment,the prevention and control of mountain-flood disaster.