基于GIS的土地利用动态监测——以民勤试验区为例

Remote Sensing with GISBased for Landuse Dynamic Detection——A Case Study of Minqin, Gansu Province, China

以甘肃省民勤县城关镇毗邻的４个乡镇为典型试验区，利用遥感与ＧＩＳ相结合的技术方法，重点监测了近１０年来该地区土地利用的具体变化状况．并在地物光谱研究的基础上，提出了适合试验区实际情况的遥感波段组合（ＴＭＲ１Ｂ４Ｇ６）和分类方法（贝叶斯方法）．对该实验区而言，这种波段组合效果最佳，贝叶斯分类的总精度也达到８８．５１％．对经制图综合而获得的土地利用专题信息，通过数据转换、软件接口与不同时期的土地利用现状图件结合，建立了一种遥感影像与ＧＩＳ一体化的研究方法，从而对该地区的土地利用与环境效应作了动态监测．研究结果表明，自１９８２～１９９５年该地区耕地面积增加了２．５％，次生盐碱化土地面积扩大了１２．４％，以及流沙面积缩小，灌丛沙堆发育，人工林衰败等多方面的变化．

The ecological environment in the wide drought area of North West China is very fragile. The contradiction between human and nature is becoming sharper and sharper and landuse changes frequently. It is necessary to monitor the dynamic change of landuse with remote sensing, especially with the combination method of RS and GIS. By selecting four neigbboring villages and towns around the city of Minqin in Gansu Province as typical study area, our research was chiefly concerned with the moitoring of the concrete changes of landuse in the latest decade. A wave band combination of Remote Sensing (TM R1B4G6) and method of classification(Bayes) was put forward on the basis of studies on groundmatter spectrum. The combination is suitable for this area and best results can be got from it. The general precision of the classifying method is 88.51%. After data transformation, software interface and combination with the map of landuse of different periods, a method of integrating RS images with GIS has been established from the thematic information of landuse obtained from mapping synthesis. The study indicates that from 1981 to 1995,the cultivated land has increased 2.5%, the area of secondary salinealkali soil has increased 12.4% and the area of quicksand has shrunk in the region.