不同栅格分辨率下赣州市石城县崩岗易发性评价研究

Evaluation of the Susceptibility to Benggang in Shicheng County,Ganzhou City Under Different Raster Cell Resolutions

探究不同栅格分辨率下崩岗易发性评价对崩岗防控具有重要意义.为开展相关研究,以赣州市石城县为例,利用地理探测器选取降雨侵蚀力、可蚀性、岩石种类、植被高度、叶面积指数、高程、坡度、归一化植被指数指标作为评价指标,划分出15、30、60、90、120 m 5种分辨率的栅格单元,以频率比(FR)为联接方法,构建频率比-随机森林(FR-RF)模型开展崩岗易发性评价.结果显示:栅格单元空间分辨率对崩岗易发性评价有一定影响,5种不同栅格分辨率下易发性结果的AUC值依次为0.840、0.830、0.830、0.820、0.810,基于随机森林模型下15 m分辨率栅格单元更适用于研究区的崩岗易发性评价(AUC值为0.840);研究区较高易发区以及高易发区主要分布在北部区域.研究结果可以为赣南地区的崩岗易发性评价提供重要参考.

It is of great significance to explore the susceptibility evaluation of Benggang under different grid unit resolutions for the prevention and control of Benggang.In order to carry out relevant research,Shicheng County of Ganzhou City was taken as an example.Rainfall erosivity,erodibility,rock type,vegetation height,leaf area index,elevation,slope,normalized difference vegetation index were selected as evaluation indexes by using geographical detector.The grid units with five resolutions of 15 m,30 m,60 m,90 m and 120 m were divided.The Random Forest model(FR-RF)was constructed to evaluation of the susceptibility to Benggang by using the frequency ratio(FR)as the linking method.The results show that:the spatial resolution of the grid unit had a certain influence on the susceptibility evaluation of the collapse.The AUC values of the susceptibility results under five different resolutions were 0.840,0.830,0.830,0.820,and 0.810,respectively.The 15 m resolution grid unit based on the random forest model is more suitable for the susceptibility evaluation of the collapse in the study area(with the AUC value of 0.840).The moderate and high susceptible area in the study area are mainly located in the northern region.The results of the study can provide an important reference for the evaluation of the susceptibility to Benggang in Gannan region.