新疆玛纳斯河流域的土地利用与退化问题

玛纳斯河流域山地、平原、沙漠、湖泊俱全，土地利用类型有8个一级类型及40个二级类。20世纪50年代以来，在山前水、土、光热组合优良地区开展大规模水土开发建设，使区内的土地资源得以充分利用，土地开发利用率达40％以上。然而，不合理的土地利用已经导致土地退化，其主要类型有土地荒漠化、耕地土壤贫瘠化、土壤次生盐渍化、土地沙漠化、水土流失、土地污染等6种。据区域土地利用特点与退化类型及原因，提出了合理利用土地与防止土地退化的5条措施，以确保玛河流域土地永续利用与持续发展。

Some Problems on the Land Use and Degradation in Manas River Watershed,Xinjiang

Composed of the mountainous regions?plains?sand deserts and a lake,Manas River watershed in Xinjiang has 8 classified and 40 sub-classified types in land use.Since recent 50years,the large-scale exploitation of water and land resources and construction have been undertaken in the perimontane areas with the fine combination of water,land and sunshine resources,the land resources in these areas has been fully utilized,and the exploitation and utilization ratio of the land has been over 40%.However,the irrational land use has resulted in land degradation that mainly includes land desertification,infertilization of farmlands,secondary salinization of soils,soil erosion,and land contamination.According to the regional characteristics of the land use and the types and causes of land degradation,five measures are put forward for the rational land use and land degradation control so as to ensure the continuous land use and sustainable development in Manas River watershed.