陕北农牧交错带土地利用变化环境效应

Evaluation of Land Use Change and its Impact on the Environment in the Farming-pastoral Ecotone in North Shaanxi Province

利用1986,1993,2003年3期Landsat TM遥感影像,在构建环境评价指标体系的基础上,借助地理信息系统技术,对陕北农牧交错带1986-2003年土地利用变化环境效应进行了分析。结果表明:陕北农牧交错带耕地、未利用土地和沙地面积不断减少,主要转化为林地和草地;居民及建设用地大幅增加,水体面积不断缩减。与此相应,生态系统功能严重退化,但环境逐渐好转,主要是人文因素逐渐增强了对环境的影响程度。土地利用格局中,耕地、林地、草地和沙地是影响环境的主要土地利用类型,其中林地、草地面积的增加是改善环境的主要原因,而沙地面积大、降水稀少成为城市化快速发展和社会经济发展以及环境保护的瓶颈,是限制环境改善或导致生态恶化的重要因素。

In this study,an index system for assessing changes in the environment in response to land use changes in the farming-pastoral ecotone of north Shaanxi Province during the period from 1986 to 2003 was developed based on analysis of Landsat TM images of the region taken in 1986,1993 and 2003 and application of GIG.The results demonstrated that the areas of cultivated land,unused land and sandy land were continuously reduced in the past 17 years.Specifically,these lands were converted to woodlands and grassla...