在西北干旱地区,土地利用结构的合理与否对区域生态环境和经济建设具有直接制约作用。本文以安西县为例,对疏勒河流域主要土地利用类型耕地、林地、草地、荒漠化土地变化驱动力以及与土地沙漠化之间的关系进行了分析研究,指出自然因素是制约土地利用水平和结构的基本要素,而人为因素对现代土地利用变化的驱动作用更为显著。耕地面积的增加主要与水资源开发利用率提高有直接关系,人口增长对耕地面积增加有间接促进作用。耕地面积减少则主要与人为不合理利用引起的土地荒漠化有关。在林地变化中,自然条件限制着该县森林发展,人为因素对林地变化的驱动作用大于自然因素的影响;草地面积减少主要是人为超载过牧和破坏的结果。此外,本文还根据数据分析并应用灰色关联度方法对导致当地土地荒漠化的最大驱动力进行判别。结果表明:引起该区荒漠化的最主要因素是超载过牧,其次是人口压力和农业开垦,区域气候变化对荒漠化的驱动作用要小于人为因素的驱动作用。分析指出,在尊重自然的基础上,进行科学管理,人为力量将成为优化干旱地区土地利用结构和提高生产力的重要驱动力。同时,提出了疏勒河流域土地利用结构合理化调整的原则建议。

In north west arid areas in China, regional eco environment and economic const ruction are controlled and limited by the rationality of land use structure Ta king Anxi county in Gansu Province as an example, this paper analyzes the change s in main land use types including cultivated land, woodland, grassland, lands in desertification and their driving forces The results show that the land use change is controll ed basically by physical conditions, and significantly affected by human activit iesThe increase in cultivated land is directly related to rising in utilizati on ratio of water resources, and the increase in population is also one of the m ain causes for cultivated land augment The cultivated land decrease is mainly related to land des ertification caused by irrational human activities Although woodland change i s also limited by physical condition, the function of human factor is more impor tant than physical influences The cause of grassland decrease is ove rgrazing and the irrational human activities Based on data analysis, the metho d of grey incidence analysis is used to identify the most important driving fact ors influencing land desertification The results show that the most important influencing factor is overgrazing, then the population pressure and land reclama tion, while regional climate change is less important than factors of human acti vities.