基于Google Earth Engine的云南省典型岩溶地区30年石漠化演变与驱动因子分析

Evolution of rock desertification and driving factors in typical karst areas of Yunnan province

为揭示云南省近30年石漠化治理工程下石漠化演变趋势与驱动因子。以典型岩溶大省云南省境内的52个典型石漠化县作为研究区,基于Google Earth Engine(GEE)和地理探测器(GeoDetector),分析其1990-2020年石漠化时空演变及驱动因子。结果如下:1990-2020年间,石漠化总体是动态改善趋势,截止2020年云南省无石漠化土地面积共计增加28776.03km^(2),主要转移方向为潜在向无石漠化转变面积12126.54km^(2),轻度向潜在石漠化转变面积11260.97km^(2),其次转变幅度较大的为轻度转变为无石漠化、中度转变为轻度石漠化,转化面积分别为8461.99km^(2)和8416.43km^(2),在空间上石漠敏感度等级总体呈现好转趋势,好转面积为56044.90km^(2),恶化面积23231.40km^(2)。出现恶化的区域主要集中在维西傈僳族自治县、德钦县、香格里拉县、罗平县、开远市和蒙自县等县。人口密度(q=0.29)、GDP(q=0.19)和年均降水(q=0.11)是研究区石漠化形成的主要驱动因子,多因子交互下年均降水和人口密度(q=0.37)、GDP和人口密度(q=0.35)与坡度与人口密度(q=0.32)这三对组合贡献最大。结果表明人活动和气候变化是驱动石漠化演变的主要原因,后续应加大封山育林与植树造林等石漠化综合治理工程力度,扩大石漠化治理成果。

In order to reveal the evolution trend and driving factors of rocky desertification control project in Yunnan province in the past 30 years,based on Google Earth Engine(GEE)and GeoDetector,the spatial-temporal evolution of rock desertification and driving factors in 52 typical rocky desertification counties in Yunnan province,a typical karst province,from 1990 to 2020,were analyzed.The results are as follows:From 1990 to 2020,rocky desertification showed a dynamic improvement trend on the whole.By 2020,the land area without rocky desertification in Yunnan province increased by 28776.03 km^(2),and the area with potential rocky desertification conversion was 12126.54 km^(2),and the area with slight potential rocky desertification conversion was 11260.97 km^(2).Secondly,the areas of slight rocky desertification transformation and moderate rocky desertification transformation were 8461.99 km^(2) and 8416.43 km^(2),respectively.In terms of space,the sensitivity grade of rock desert showed an overall improvement trend,with an improved area of 56044.90 km^(2) and a deteriorated area of 23231.40 km^(2).The areas showing deterioration were mainly in Lisu ethnic autonomous county,Deqin,Shangri-La,Luoping,Kaiyuan and Mengzi counties.Population density(q=0.29),GDP(q=0.19)and annual average precipitation(q=0.11)were the main driving factors for the formation of rocky desertification in the study area,and annual average precipitation and population density(q=0.37),GDP and population density(q=0.35)and slope and population density(q=0.32)contributed the most to the combination under multi-factor interaction.The results show that human activities and climate change are the main reasons driving the evolution of rocky desertification,and the project of comprehensive control of rocky desertification,such as mountain closure and afforestation,should be strengthened to expand the achievements of rocky desertification control.