西藏林芝市土地利用程度变化及其空间异质性分析

Study of Land Use Intensity Change and Its Spatial Heterogeneity of Nyingchi City in Tibet

【目的】揭示青藏高原高山峡谷地区土地利用程度空间分异特性,为当地国土空间规划提供理论依据。【方法】基于2010年和2020年2期Landsat卫星遥感数据获取30 m网格土地利用数据,采用空间自相关分析法分析林芝市土地利用程度综合指数及其变化的空间分异特征。【结果】林芝市较强和强土地利用程度网格单元主要分布在低海拔区域和雅鲁藏布江、尼洋河宽河谷流域,弱和较弱土地利用程度网格单元主要分布在高海拔区域。2010—2020年,林芝市土地利用程度呈现出由中等和较强等级向强等级转变的态势。林芝市土地利用程度具有较显著的全域空间正相关性,有明显的集聚特征,且集聚的趋势平稳。局域空间自相关特征为市域东北部和西北部为低—低集聚区,市域低海拔和雅鲁藏布江、尼洋河宽河谷地区为高—高集聚区。土地利用程度变化(增加)空间上整体集聚,局域特征以尼洋河宽河谷流域、其他人口活动密集地区和低海拔区为高—高集聚,而低—高集聚区分布在高—高集聚区外围。【结论】林芝市土地利用程度逐渐增强,土地利用程度及其变化都不是随机分布的,土地利用程度变化高的区域彼此相邻,土地利用程度变化低的区域彼此相邻。

[Purpose]To reveal the spatial heterogeneity characteristics of land use intensity of alpine gorge in Tibetan Plateau,providing a theoretical basis for local territorial spatial planning.[Method]Based on the Landsat satellite images in 2010 and 2020,the data of land use in 30 meters grid were obtained,and the spatial heterogeneity characteristics of land use intensity and its change in Nyingchi were analyzed by spatial autocorrelation analysis method.[Results]The grid units of stronger and strongest level of land use intensity were mainly distributed in the low altitude areas and the wide valleys of the Yarlung Tsangpo River and the Nyang River,the grid units of weakest and weaker level of land use intensity were mainly distributed in the high altitude area.From 2010 to 2020,the increased area of strongest level came from the reduced area of middle and stronger level of land use intensity.The land use intensity in Nyingchi had relatively strong positive global spatial auto-correlation with Moran’sⅠ,had obvious spatial aggregation law.The graph of local autocorrelation analysis showed that land use intensity low-low typology was in the northeast and northwest in Ny-ingchi,high-high typology was in the low altitude areas and the wide valleys of the Yarlung Tsangpo River and the Nyang River.The land use intensity change also had positive global spatial autocorrela-tion in Nyingchi from 2010 to 2020,high-high typology was in the wide valleys of the Nyang River,other densely inhabited districts and low altitude areas,but the low-high typology distributed around the high-high typology areas.[Conclusion]The land use intensity gradually strengthens,the land use intensity and its changes in Nyingchi is not disorderly,the regions with high land use change are adjacent to each other,and the regions with low land use change are adjacent to each other.