1992年以来科尔沁沙地土地利用变化分析——以科尔沁左翼后旗为例

Analyze of the land use change in Horqin Sandy Land since 1992:A case study of Horqin Zuoyihou

为了解科尔沁沙地20世纪90年代以来的土地利用变化及人类活动程度情况,以科尔沁左翼后旗为例,选取1992、2001和2014年的土地利用数据,从网格尺度下的综合土地利用动态度、土地利用变化重要性指数、土地利用程度、作物生育期降水量等方面来分析。结果表明:土地利用呈现出"西草东耕、中部交错"的基本格局,耕地、林地、建设用地、沙地有所增加,草地、水域、盐碱地减少。土地利用动态度为19%~29%的地区主要集中于中部,此地区受人类浩动干扰影响较大。土地利用变化面积比重由41.7%增加到45%,土地利用变化剧烈,草地、耕地、林地、沙地间的相互转化是主要的变化类型,当地仍处于土地利用的发展期。作物生育期降水量在391~432mm的地区耕地增幅达44.7%,降水量为293~340mm的地区增幅为10.5%,新增耕地优先选择降水较多的地区。对于该地区今后发展来讲,一方面要继续加强土地利用管理,限制耕地的开垦,另一方面退耕也要因水而宜,西部可优先考虑退耕,东部可作为种植业的优先发展区。

In order to understand the land use changes and the degree of human activities in Horqin sandy land since 1990 s,the land use data in 1992,2001 and 2014 is analyzed by taking Horqin Zuoyihou Banner as a study case.Several aspects including the land use dynamic degree at the grid scale,land use change significance index,land use degree and the rainfall during crop growth are analyzed for the area during different periods.The results show that.1）Grass land is distributed in the west while cultivated land mainly in the east,and different land types including grass land,cultivated land,forest are distributed in the central area.Cultivated land、forestland、construction land and sand land increased while grass,water area and salt alkali land decreased.2）Places that land use dynamic degree between 19%and 29% are most distributed in the central area,as the human activities are stronger.3）The percent of land use changes area increased from 41.7% to 45%.Therefore,land use changes were dramatic.The transformations among grass land,cultivated land,forest land,sandy land were dominated in the area.The land use in this area is also developing at the stage.4）The increase of cultivated land in area where rainfall during crop growth was between 391 and 432 mm was 44.7%.Meanwhile,the increase between 293 and 340 mm was 10.5%.Newly cultivated land ispreferred to areas with more rainfall.For the future development of this area on the one hand,it is worthwhile to strengthen land use management and control reclamation for cultivated land.On the other hand,returning cultivated land should consider rainfall conditions.The west should be given priority to return cultivated land,and the east is more suitable for planting.