基于DEM的靖边县土地利用变化分析

发布时间：2019-07-10 11:04

【摘要】：地形因素与土地利用行为有着密切的联系，不同地形、地貌特征下的土地利用格局不仅反映了人类的干扰程度与土地利用变化结果，同时也是社会经济条件与自然条件相互作用的直接响应表现。地处黄土高原与毛乌素沙地过渡地带的陕西省靖边县，区域内地形条件复杂，土地利用类型多样，受“退耕还林（草）”和建设“21世纪能源基地”等国家政策的影响，土地利用变化剧烈。通过分析土地利用变化可以反映区域内不同地形地貌区域土地利用变化对政策的响应过程，对于区域土地合理利用与开发提供理论依据。以30m分辨率的DEM和四期TM遥感影像为数据源，利用遥感和GIS手段，得出地形因子分类依据，依据DEM提取研究区的高程、坡度、地形梯度、地形起伏度和地表粗糙度信息并进行分级，采取决策树分类方法对1995、2000、2005、2010年四期TM影像进行土地利用分类，获取土地利用数据，借助GIS空间分析功能分析地形要素与土地利用变化之间的关系。得到以下结论：（1）研究区耕地、水域、草地、其它土地持续下降；林地和建设用地持续增长。在2010年，林地和草地是靖边县的优势地类；（2）研究区内，地貌主要为微起伏的草滩区和高起伏的丘陵区；高程分布范围在1300-1600m，坡度以平地和缓平地为主；不同地貌区域、高程分级、坡度分级和地形梯度下，林地分布均匀，并且一直保持优势地类状态；耕地和建设用地在低海拔、坡度平缓区域分布集中，对区域具有选择性；（3）景观指数分析表明，不同地形区域内，斑块密度减少，，聚集度增加，多样性指数增加，破碎度程度降低；在山地和丘陵区域、高程大、坡度大的区域图斑形状复杂，人为干扰较小；（4）生态风险程度降低，主要风险程度由三级降为二级，说明退耕还林（草）工程取得了显著成果，研究区植被覆盖度增加，生态环境明显改善。
[Abstract]:The terrain factor is closely related to the land use behavior, and the land-use pattern under the characteristics of different terrain and physiognomy not only reflects the human's disturbance degree and the land-use change result, but also the direct response of the interaction between the social and economic conditions and the natural conditions. It is located in Jingbian County of Shaanxi Province, which is a transitional zone between the Loess Plateau and the Mu Us Sandy Land. The terrain condition in the region is complex, the land use type is diverse, the "Cropland to Forest (Grass)" and the construction "Energy Base of the 21 ~ (st) Century" are affected by the national policies, and the land use change is violent. The analysis of the change of land use can reflect the response process of land-use change to the policy in different terrain and landforms in the region, and provide the theoretical basis for the rational utilization and development of the regional land. Using the DEM and the four-phase TM remote sensing image with the resolution of 30 m as the data source, using the remote sensing and GIS means, the classification of the terrain factors is obtained, and the elevation, the slope, the terrain gradient, the topographic relief and the surface roughness information of the study area are extracted according to the DEM. The classification of land use in 1995,2000,2005 and 2010 is carried out by the decision tree classification method. The data of land use is obtained, and the correlation between the terrain elements and the land use change is analyzed by means of the spatial analysis of GIS. The following knot is obtained. Comment: (1) The area of cultivated land, water area, grassland and other land in the study area is continuously reduced; and the forest land and the construction land are held. Continued growth. In 2010, forest land and grassland were excellent in Jingbian county. Potential land; (2) The landform is mainly in the area of the micro-fluctuation and the hilly region with high fluctuation; the elevation distribution is in the range of 1300-1600 m, and the slope is dominated by the ground and the gentle ground; and the different physiognomy areas and the cultivated land and the construction land are centralized in a low-altitude, gradient-flat region distribution set, has the selectivity; (3) the landscape index analysis shows that, In different terrain areas, the density of the patch is reduced, the aggregation degree is increased, the diversity index is increased, and the degree of fragmentation is reduced; in the mountainous and hilly areas, the area with large elevation and large slope is complex in shape and shape and (4) the ecological risk degree is reduced, and the main risk The degree of vegetation coverage in the study area is increased from the third to the second level, indicating that the project has achieved remarkable results.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P208;F301.2

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