基于GEE的天山野果林分布区土地利用变化分析

Land use change analysis of Tianshan wild fruit forest distribution area based on GEE

基于谷歌地球引擎(Google earth engine,GEE)遥感大数据云平台,通过Landsat系列影像,运用随机森林算法,结合光谱指数、地形特征进行土地利用分类,通过地学信息图谱、土地利用动态度分析天山野果林分布区1997—2021年土地利用时空变化特征。结果表明,通过GEE平台,利用随机森林算法,可以快速实现土地利用分类,总体分类精度均大于90.00%,Kappa系数均高于0.85;1997—2021年天山野果林分布区主要为耕地、林地和草地,三者占总面积的90%以上;土地利用变化以草地向耕地的转变以及林地向草地的转变为主;建设用地、耕地、水域面积持续增加,变化呈聚集分布,林地先减后增,总体占地面积减少严重;建设用地增长速度最大,变化最为剧烈,未利用地、林地总体减少速度较大,变化较为剧烈。

Based on Google earth engine(GEE)remote sensing big data cloud platform,through Landsat series images,using random forest algorithm,combined with spectral index,topographic features for land use classification,through the geographic information mapping,and the spatial and temporal changes of land use of Tianshan wild fruit forest distribution area from 1997 to 2021 were analyzed through geographic information mapping and land use dynamics.The results showed that through GEE platform and random forest algorithm,land use classification could be realized quickly,and the overall classification accuracy was greater than 90.00%,and the Kappa coefficient was higher than 0.85;from 1997 to 2021,the Tianshan wild fruit forest distribution area was mainly arable land,forest land and grassland,and the three accounted for more than 90%of the total area;land use changes were dominated by the transformation of grassland to arable land and the transformation of forest land to grassland;construction land,arable land and water area continued to increase,the change showed the aggregative distribution,forest land decreased first and then increased,and the overall land area decreased seriously;the growth rate of construction land was the largest and the change was the most drastic,the overall reduction rate of unused land and forest land was large and the change was more drastic.