1980—2020年克鲁伦河流域草地的时空变化

Temporal and Spatial Changes of Grassland in Kherlen River Basin from 1980 to 2020

[目的]分析克鲁伦河流域草地时空变化特征,对比分析中蒙两国草地变化规律,以期推动地方生态环境保护与建设,为跨境草原的可持续发展提供科学参考。[方法]以克鲁伦河流域为研究对象,基于面向对象的随机森林分类方法对Landsat系列影像进行信息提取,获得1980—2020年克鲁伦河流域5期土地覆被数据,并通过草地动态度模型、草地变化转移矩阵、质心模型及相关性分析的方法对比分析中蒙两侧草地变化及其驱动因素。[结果](1)1980—2020年克鲁伦河流域草地整体呈减少趋势,共减少486 km^(2),其中中国一侧草地增加130 km^(2)(0.88%),裸土地的转入是草地面积增加的主要原因;蒙古国一侧减少616 km^(2)(0.61%),主要转化为裸土地和耕地;(2)克鲁伦河流域草地质心向东北方向移动1.6 km。[结论]克鲁伦河流域草地退化的是自然因素和人为因素协同作用的结果,但从其面积转移来看,人类活动是导致其退化的直接原因。

[Objective] The temporal and spatial variation characteristics of grassland in the Kherlen River basin were analyzed,and the change laws of grassland in China and Mongolia were compared in order to promote the protection and construction of the local ecological environment and to provide a scientific reference for the sustainable development of cross-border grassland.[Methods] Information was extracted from a series of Landsat images based on object-oriented and random forest classification methods to obtain five-phase land cover data for the Kherlen River basin form 1980 to 2020.Grassland changes and the driving factors of grassland change on both sides of the China-Mongolia border were compared and analyzed by means of a grassland dynamic attitude model,a grassland change transfer matrix and a centroid model.[Results](1) Grassland in the Kherlen River basin declined from 1980 to 2020.A total reduction of 486 km^(2) was found,where grassland on the Chinese side increased by 130 km^(2)(0.88%).The transfer of bare land was the main reason for the increase in the grassland area.The Mongolia side decreased by 616 km^(2)(0.61%),as grassland was mainly converted into bare land and cultivated land.(2) The grassland centroid in the Kherlen River basin moved 1.6 km northeast due to the loss of grassland in the middle and lower reaches of the Kherlen River.[Conclusion] The loss of grassland in the Kherlen River basin was the result of the combination of natural and human factors.From the perspective of grassland area transfer,human activity was the direct cause of its grassland loss.