民勤荒漠区生态变化初探

在民勤荒漠区，荒漠植被的演替是经过历史的环境变迁，渐变的过程。由于人类活动的干扰增加，石羊河水系生态平衡失调，中上游用水量增加，流入民勤的径流量减少，造成过量开采地下水，导致地下水位的迅速下降。再加乱垦滥挖，造成植被演替的速度加快，总的趋势为植被覆盖度降低、植物种类减少、生长势减弱、生态环境恶化。

A Preliminary Analysis on Ecological Changes in Minqin Desert Area

The desert vegetation evolution in Minqin desert area is an activating balance processing gradually under the history and environment change.The natural vegetation evolution is now faster than that of the past because of the fast declining of underground water and blind land reclamation.Especially,the increased man disturbance to natural fragile environment,the eco balance broken in Shiyang basin,the surface runoff reduced year by year in Minqin area,over use of underground water etc.The tendency of Minqin environment is decilned all in all with the reduced plant coverage,species and growth.