我国以植树造林为核心的生态环境建设取得了很大成绩,到1997年全国已累计造林4627万hm²,其中“三北地区”3024万hm²。但也存在着很大问题,主要表现在平均造林成活率仅25%,保存率仅13%。经分析,西北地区少雨干旱,缺土壤水是“年年造林不见林”的主要原因。分析表明,水是西北地区生态系统重建的根本,而跨流域调水、加强水资源管理、雨水资源化、发展节水农业、普及节水意识等,是解决西北地区水资源短缺的根本途径。

Up to now,great progresses in the construction of eco-environment have been made,especially afforestation in the"Three Norths"of North,Northeast and Northwest China.Accord-ing to statistics,up to1997,afforested area of the whole country had reached46.27million ha,among of them30.24million ha were located in the"Three Norths".However,in the process,some problems still exist which need to be solved as soon as possible,in particular,the relative low survival rate and preservation rate which are only25%and13%respectively.The analyses show that scarce rainfall,drought and the shortage of soil moisture are the main reasons for this phenomenon.Therefore,water resources are the cores of the reconstruction of ecosystem in Northwest China.The effective approaches to overcome the shortage of water resources there in-clude interbasin water transfer,effective water management ,resourcelization of rain water,de-veloping water-saving agricultural techniques,popularizing water-saving awareness,etc.