基于RS+GIS的粤港澳大湾区水土流失时空演变分析

Spatial and Temporal Evolution of Soil and Water Loss in the Guangdong-Hong Kong-Macao Greater Bay Area Based on RS+GIS

利用RS+GIS技术,以土地利用类型图、数字高程图、MODIS遥感影像作为数据源,利用多因子综合判别法分析2000—2018年粤港澳大湾区的水土流失变化,并对影响水土流失的主要因子进行时空演变分析。结果表明:近20年来粤港澳大湾区各市水土流失均得到明显改善,各程度土壤侵蚀面积均呈减少趋势;各市植被覆盖度均呈增加趋势,其中肇庆、惠州、江门的植被覆盖度相对较高,佛山、中山、东莞的植被覆盖度相对较低,深圳市的植被覆盖度增长最快;造成粤港澳大湾区水土流失的主要原因可归结为自然因素和人为因素,进一步分析认为,水土流失得到改善的主要原因是由于植被覆盖度的增加,而土地利用类型的改变并非主要原因。

Taking land use type map,digital elevation map and MODIS remote sensing images as data source and using RS and GIS technology and multi-factor comprehensive discrimination method,the paper analyzed the variation of soil and water loss in the Guangdong-Hong Kong-Macao Greater Bay Area during the period of 20002018 and analyzed the temporal and spatial evolution of the main factors affecting soil and water loss.The outcomes show that a)in recent 20 years,soil and water loss in the Guangdong-Hong Kong-Macao Greater Bay Area all has been significantly improved and the soil and water loss area of each degree shows a decreasing trend;b)the vegetation coverage in all cities shows an increasing trend.Among them,the vegetation coverage of Zhaoqing,Huizhou and Jiangmen is relatively higher,Foshan,Zhongshan and Dongguan is relatively lower and the vegetation coverage in Shenzhen is growing fastest and;c)The main causes of soil and water loss in the Guangdong-Hong Kong-Macao Greater Bay Area can be attributed to natural factors and human factors.Further analysis shows that the improvement of soil and water loss is mainly due to the increase of vegetation coverage and the change of land use type is not the main reason.