基于GlobeLand 30的哈密市2000-2020年土地利用格局变化研究

A Study on Change of Land Use Pattern in Hami City During 2000-2020 Based on GlobeLand 30

[目的]研究新疆维吾尔自治区哈密市近20 a的土地利用变化,为该地区土地利用规划及生态环境保护提供有力支撑。[方法]基于2000,2010,2020年的GlobeLand 30数据集,通过利用转移矩阵、坡度分布指数、标准差椭圆以及土地利用重心迁移,分析哈密市2000-2020年土地利用的时空变化特征。[结果]①哈密市2000-2020年土地利用变化比较明显。2020年各土地利用类型面积比例为:未利用地>草地>耕地>林地>建设用地>水域。哈密市虽然面积大但能利用的绿洲面积较小。2020年草地面积为10226.39 km^(2),水域面积为295.17 km^(2)。2000-2020年土地利用类型变化量中,草地的减少量最大,流失面积为671.48 km^(2),主要转换成未利用地、林地和少量耕地;建设用地增量最大,面积高达405.60 km^(2)。2000-2020年其他土地利用类型中林地和耕地面积呈增长趋势;未利用地和水域呈减少趋势,其中水域面积的减少量很小,基本保持稳定。②2000-2020年草地在5个坡度梯度上分布比较均匀;而耕地和建设用地基本分布在Ⅰ级和Ⅱ级坡度梯度,耕地在Ⅰ级坡度梯度上显优势分布;林地在Ⅰ级坡度梯度上面积最大;未利用地分布面积随着坡度梯度的增加而减少。③2010-2020年土地利用变化与2000-2010时段的变化相比方向性较明显,范围更广,重心向西北方向迁移。[结论]2000-2020年哈密市的土地利用变化有着明显的时空特征,坡度对各地类分布的影响较为明显。

[Objective]The land use change in Hami City,Xinjiang Uygur Autonomous Region,over the past 20 years was studied to provide strong support for land use planning and ecological environment protection.[Methods]Based on the GlobeLand 30 datasets in 2000,2010,and 2020,the spatial-temporal change characteristics of land use in Hami City from 2000 to 2020 were analyzed using a transfer matrix,a slope distribution index,a standard deviation ellipse,and the land use and use center-of-gravity migration.[Results]①The land use change was obvious in Hami City from 2000 to 2020.The proportion of land use types in 2020 was in the order of unused land>grassland>cultivated land>forest>construction land>water area.Although Hami occupied a large area,the usable oasis area was small.In 2020,the grassland area was 10226.39 km^(2),and the water area had the smallest proportion,with an area of 295.17 km^(2).In terms of land use type change from 2000 to 2020,grassland had the largest reduction,and the loss area was 671.48 km^(2).It was mainly converted into unused land,forest,and a small amount of cultivated land.The increase in construction land was the largest,with an area of 405.60 km^(2).From 2000 to 2020,the area of forest and cultivated land showed an increasing trend,while the unused land and water areas showed a decreasing trend.The reduction of water area was very small,and the area remained stable.②From 2000 to 2020,grassland was evenly distributed on the five slope gradients.The cultivated and construction land were distributed in gradeⅠand gradeⅡslope gradients,and cultivated land was dominant in gradeⅠslope gradient.The area of forest was the largest on gradeⅠgradient.The distribution area of unused land decreased with the increase in the slope gradient.③Compared with 2000-2010,the land use change in 2010-2020 had a more obvious directionality and wider range,and the center of gravity shifted to the northwest.[Conclusion]From 2000 to 2020,the land use change of Hami City had obvious space-time characteristics,and the influence of the slope on the distribution of various types is significant.