1987—2019年吉林省梨树县土地利用动态研究

Dynamic analysis of land use in Lishu county of Jilin province from 1987 to 2019

【目的】定量分析梨树县土地利用状况,为梨树县土地利用结构调整、农业布局优化提供科学参考。【方法】文章以梨树县为研究区,在1987年、2003年和2019年Landsat 5/TM、Landsat 8 OLI影像的基础上,进行支持向量机分类(SVM)。同时,以转移矩阵、土地利用动态度、土地利用程度、信息熵等为主要方法实现对梨树县30余年土地利用动态的定量表达。【结果】(1)耕地、林地、草地和建筑用地的变化最为显著,其中耕地面积增加态势明显,1987年、2003年、2019年面积占比均保持在75%以上。(2)林地形态较为集中,面积持续减少,以分布在东南部为主;水域、草地主要接受来自耕地的转入,呈现出“先减后增”的态势,表明这一时期人类干预对土地利用起到积极作用。(3)建筑用地不同程度地接受来自耕地、林地、其他用地的转入。(4)从信息熵原理来看,梨树县土地利用类型分布不均匀,均衡度较低,均质性较弱。【结论】经济发展在一定程度上伴随着建筑用地的扩张和耕地面积的减少,从而改变土地利用格局。同时,气候变化对土地利用也造成了影响。该结果及结论可为研究区农业转型升级、乡村振兴、农业风险防范提供支持。

[Purpose]To quantitatively analyze the land use status of Lishu County,and provide scientific reference for the adjustment of land use structure and the optimization of agricultural layout.[Method]With Lishu County as the research area,support vector machine classification(SVM)was performed on the basis of Landsat 5/TM and Landsat 8 OLI images in 1987,2003 and 2019.At the same time,the main methods of transfer matrix,land use dynamics,land use degree,information entropy,etc.are used to achieve quantitative expression of land use dynamics in Lishu County for more than 30 years.[Result](1)The changes in arable land,woodland,grassland and construction land were the most significant.Among them,the area of arable land increased significantly,and the area accounted for more than 75%in 1987,2003,and 2019.(2)The form of forest land is relatively concentrated,and the area continues to decrease,mainly distributed in the southeast;waters and grasslands mainly receive transfers from cultivated land,showing a trend of“decreasing first and increasing later”,indicating that human intervention has affected the land use during this period.(3)Construction land accepts transfers from cultivated land,woodland and other land to varying degrees.(4)Information entropy shows,the distribution of land use types in Lishu County is uneven,with a low degree of balance and weak homogeneity.[Conclusion]To some extent,economic development is accompanied by the expansion of building land and the reduction of arable land,which changes the pattern of land use.At the same time,climate change also has an impact on land use.The conclusion can provide support for agricultural transformation and upgrading,rural revitalization and agricultural risk prevention for the study area.