近28年金昌市土地利用动态变化及模拟预测

Land-use dynamic change of Jinchang City in the last 28 years and simulation prediction

基于1987、1999、2006和2014年的4期Landsat TM/ETM+和Landsat-8 TIRS遥感影像,综合运用RS与GIS技术手段,在Workstation平台下选择Arc Tools和Arc模块,获取土地利用矢量数据,再利用IDRISI Selva 17.0软件平台下的CA-Markov模型对金昌市土地利用空间格局和发展趋势进行模拟。结果表明:近28年来,金昌市建设用地、林地和耕地增加,其中建设用地增加最突出,增加了96.98%,且增加主要集中于人类活动强烈地带——城镇和工矿业所在地及交通线附近;而未利用地、草地和水域减少,并以未利用地和草地减少较突出,分别减少5.13%和4.32%;在土地利用类型相互转化中,未利用地向建设用地、草地向未利用地和水域向未利用地的转变规模最显著;未来16年,金昌市土地利用变化大致保持原有的变化趋势,但变化幅度增大,即建设用地、林地、耕地和水域将处于增加趋势,而未利用地将减少并处于被高度开发阶段,草地将减少且还会有明显退化趋势;因此,保护草地对金昌市生态环境及防风固沙显得尤为重要。

Based on the four-period remote sensing images of Landsat TM / ETM＋and Landsat-8TIRS in 1987,1999,2006 and 2014,combined with RS and GIS technology,the land-use vector data were obtained. Additionally,the CA-Markov model was employed to simulate the spatial pattern and development tendency of the land use in Jinchang City with IDRISI Selva 17.0 software. The results showed that the built-up land,forest land and cropland presented an increasing trend over the past 28 years in the study area. The built-up land was increased prominently by96.98%,and mainly located in towns,industry-mining sites and the areas neighboring traffic lines,which were influenced intensively by human activities. However,the unused land,grassland and water-body showed a decreasing trend,and the unused land and grassland decreased by5. 13% and 4. 32%,respectively. The most significant conversions were found from the unused land to built-up land,grassland to unused land,and water-body to unused land. In the next 16 years,the land-use change in Jinchang would roughly keep its previous trends,but the change amplitude would increase. The area of built-up land,forest land,cropland and water-body would increase,while that of the unused land would decrease and would be highly developed. The area of grassland would decrease and the degradation would be obvious. Therefore,it is particularly important to protect the grassland for ecological environment and windbreak and sand fixation.