洱海流域上游2005-2019年土地利用时空动态特征分析

土地利用对湖泊水质具有重要影响，研究其在重要时间节点的转化对保护洱海水质具有重要意义。基于人机交互解译遥感影像，得到2005年和2019年两期洱海流域上游的土地利用数据，运用地理信息系统（geographic information system，GIS）空间分析、转移矩阵等多种研究方法，分析洱海流域上游近14a来各种土地利用类型在时间、空间及数量上的动态变化情况。结果表明：耕地、林地和草地是洱海流域上游主要地类，耕地分布在中、南部平缓地带，林地和草地呈环状分布在盆地边缘，城镇用地零散分布在耕地中，且靠湖泊区域更为集中；14a间，转换主要在耕地、林地、建设用地和草地四种土地利用类型之间进行。建设用地和草地是总面积增加和减少最多的地类，分别为47.240 km2和97.398 km2；土地利用动态度呈现两极分化态势，园地是动态度最大，为1 549.895%，林地动态度最低，为0.198%。研究结果可为洱海流域上游的土地利用规划、生态保护提供理论支撑。

Analysis on the Spatio-temporal Dynamic Characteristics of Land Use in the Upper Erhai Lake Basin from 2005 to 2019

Land use has an significant impact on the water quality of the lake, and research on its transformation at key time points is of great significance for the protection of the water quality of the Erhai Sea. The two periods of land use data in the upper reaches of the Erhai Basin in 2005 and 2019 were obtained utilizing human-computer interaction to interpret remote sensing images. The dynamic changes of various land use types in time, space and quantity in the upper reaches of the Erhai Basin in the past 14a were analysed using various research methods such as geographic information system (GIS) spatial analysis and transfer matrix. The results show that cultivated land, forestland and grassland are the main land use types in the upper part of the Erhai Basin. Cultivated land is scattered in the central and southern gently sloping areas, forestland and grassland are distributed in a circular pattern around the basin edges, and urban land is dispersed among cultivated land, which is more concentrated around the lake.During the 14a period, the conversion mainly takes place between four land use types: cultivated land, forestland, construction land and grassland. The land types with the greatest growth and decline area are construction land and grassland, with 47.240 km2 and 97.398 km2 respectively.The land use dynamics?show a polarisation, with grassland being the most dynamic (1,549.895%) and forestland being the least dynamic (0.198%).The results of the study can provide theoretical support for land-use planning and ecological protection in the upper reaches of the Erhai Basin.