西北地区生态环境建设应量水量土而行

Ecological Environment Construction in Northwestern China Should Be Done in Accordance with Local Soil and Water Resources

西北地区水资源缺乏 ,土壤资源同样有限 ,生态环境建设应量水量土而行。年降水量少于 2 0 0mm且无水源可引可抽的地区 ,不仅不宜人类居住 ,而且高等动植物也难以生存 ,可采取机械或化学方式固结地表物质 ,并采取移民措施 ;年降水量 2 0 0～ 40 0mm的地区 ,应以栽植耐旱灌草为主 ,并采取拦蓄措施充分利用降水 ;年降水量 40 0～ 60 0mm的地区 ,可建设确保口粮的基本农田 ,并建好集雨节灌设施 ;缺雨干旱地区植树种草 ,拦蓄工程措施必须先行 ,当地乡土树种的选择应以 3～

Ecological environment construction in northwestern China should be alone accordance with local soil and water resources because both water and soil are scarce there.Mechanical and chemical methods may be applied to solid land surface materials and resettlement measures can be used in areas of annual precipitation of less than 200 mm and without underground water available because the area is not suitable to human beings and even difficult for advanced plants. In the areas with precipitation of 200 to 400 mm, the main plantation should be drought resistant shrubs and grass and water retaining measures should be adopted to make full use of rainfall. Basic farmland for ensuring grain ration may be constructed in the areas of annual rainfall of 400 to 600 mm, and projects of water collection engineering and water saving irrigation should be applied. Water retaining projects and plantation of grass and trees should be employed beforehand in dry areas, and selection of local varieties of trees must be based on the growing condition of 3 to 5 years seedlings.