喀斯特山区地表水时空变化分析——以贵阳市为例

Analysis of Temporal and Spatial Variations of Surface Water in Karst Mountainous Areas——Taking Gui yang city as an example

本研究选择贵阳市2000年、2010年、2020年3期landsat7ETM数据,通过归一化水体指数(NDWI)、改进归一化水体指数(MNDWI)和支持向量机(SVM)提取贵阳市地表水面积,通过数字高程模型(DEM)获得贵阳市河网信息,利用混淆矩阵对NDWI、MNDWI、SVM法进行精度评价,分析地表水时空变化特征及其驱动因素。结果表明:2000-2020年贵阳市地表水面积缩减42.46 km^(2),面积变化百分比为28%;2010-2020年地表水缩减面积最大,缩减面积达到23.96 km^(2),面积变化百分比为17.99%,近20 a贵阳市地表水呈缩减趋势。采用Pearson相关性分析,降雨量、蒸发量、径流量、是影响地表水面积变化的次要因素,气温、人口密度、生产总值是影响面积变化的主要因素。本研究可为喀斯特山区水资源的保护和利用提供参考。

In this study,the landsat7etm data of Guiyang City in 2000,2010 and 2020 are selected.The surface water area of Guiyang city is extracted through normalized water index(NDWI),improved normal⁃ized water index(MNDWI)and support vector machine(SVM).The river network information of Guiyang city is obtained through digital elevation model(DEM).The accuracy of NDWI,MNDWI and SVM meth⁃ods is evaluated by using confusion matrix,and the spatial-temporal variation characteristics and driving factors of surface water are analyzed.The results show that from 2000 to 2020,the surface water area of Guiyang city decreased by 42.46 km^(2),and the area change percentage was 28%;From 2010 to 2020,the area of surface water decreased the most,reaching 23.96 km^(2),with an area change percentage of 17.99%.In the past 20 years,the surface water in Guiyang has shown a decreasing trend.According to Pearson correlation analysis,rainfall,evaporation and runoff are the secondary factors affecting the change of surface water area,while temperature,population density and GDP are the main factors affect⁃ing the change of surface water area.This study can provide reference for the protection and utilization of water resources in karst mountain areas.