台兰河流域土地利用变化及其景观格局特征研究

Study on the Characteristics of Land Use Changes and Landscape Pattern in Tailan River Watershed

在遥感和GIS技术支持下,获取了自1990年以来台兰河流域3期土地利用数据,在GIS空间分析模块下对台兰河流域土地利用及其景观格局特征进行了研究。结果表明:1990-2005年,土地利用变化表现出耕地和沙地明显增加,分别增加35 027.11 hm2和10 443.46 hm2,而草地和天然林地面积锐减,其中草地净减少59 965.95hm2,反映出流域有大面积拓荒的趋势。随着耕地面积的不断增大,引发农业用水和生态用水之间的矛盾,天然植被受到破环,生物多样性减少。老绿洲土壤盐渍化面积总体呈减小趋势,新绿洲及绿洲外围局部地区土壤盐渍化呈恶化趋势。

The three-stage spatial data of land use change was established based on ArcGIS by using TM remote images and DEM as data sources. GIS spatial analysis tool was applied to trace the land use change and to characterize the landscape pattern in the Tailan River watershed since 1990. The results indicated that cropland and sandy land increased by 35 027.11 hm^2 and 10 443.46 hm^2 respectively, while grassland area decreased by 59 965.95 hm^2 from 1990 to 2005. This suggests that large-scale reclamation occurred in this area. The remarkable increase of cropland resulted in the damage of natural vegetation, reduction of biodiversity and conflict between agricultural and ecological water demands. The area suffering from salin ization in the old oasis trend to decrease, while the area of salinization in parts of the new oasis periphery presented an aggravating tendency.