塔里木盆地水资源利用与生态平衡及土地沙漠化

在气候极端干旱的塔里木盆地 ,人类开发利用水资源 ,使水资源消耗由以自然生态为主转向以人工绿洲生态为主 ,从而使生态环境发生相应变化 ,这种变化的基本规律是 :沙漠化与绿洲化并存 ,互有消长 ,“人进沙退”和“沙进人退”皆有 ,但以沙进人退为主。上游灌区引水增加 ,人工绿洲由原先多分布在河流下游三角洲向山前平原推进 ,面积不断扩大 ,使这里生态环境改善。河流中、下游由于水量减少 ,古代绿洲衰亡 ,天然植被退化 ,沙漠化扩大 ,使生态环境不断恶化。而处于沙漠和绿洲之间由林地、草地和自然水域构成的过渡带不断缩小 ,防护功能不断减弱 ,形成了沙漠危逼绿洲的严峻态势。

Utilization of Water Resources,Ecological Balance And Land Desertification in the Tarim Basin Xinjiang

Because of the human exploitation and utilization of the water resources in the Tarim Basin, the water resources consumption has changed from mainly by natural ecosystem to by artificial oasis ecosystem, and the environment has changed correspondingly. The basic changes are:desertification and oasis development coexist, both "the human being advance and the desert retreat" coexist, but the latter is the dominant. In the upper reaches, water volume drawing to irrigated agricultural area has increased,artificial oases had been enlarging and moving from the deltas in the lower reaches of many rivers to the piedmont plains. In the middle and lower reaches of the Tarim River, the flow has decreased, old oases have declined, natural vegetations have been degenerating, desertification has been enlarging, and the environment deteriorated. The transition regions, which are consisted of forestland, grassland and waters between the desert and the oases have been decreasing continuously, their shelter function to oases has been weakened, the desert is threatening the oases seriously.