民勤盆地生态功能类型区划分与生态用水分析

Study on the Ecological Functional Divisions and Ecological Water Consumption in the Minqin Basin

民勤生态十分脆弱,主要是生态用水严重不足,导致防风阻沙植被衰败。将民勤划分为4个生态功能类型区,即:Ⅰ绿洲生态功能类型区、Ⅱ绿洲边缘生态功能类型区、Ⅲ固定-半固定沙丘生态功能类型区、Ⅳ流动沙丘生态功能类型区。对每个生态功能类型区的生态功能和植被状况进行了调查分析,根据民勤的水资源现状和各个生态功能类型区所发挥的不同生态功能,提出只在绿洲边缘生态功能类型区进行人工补充水分,建立人工植被。并对该区域所需的人工补水量进行了计算,结果表明,这一生态功能类型区每年需要人工补充植被生态用水量为1.2×108m3。

The Minqin Basin （38°05′ -39°06′N, 103°02′ - 104°02′E） is located in the lower reaches of the Shiyang River, its western, northern and eastern sides are surrounded by the Badain Juran Desert and the Tengger Desert, and the oasis along both riversides of the Shiyang River in its south connects with Liangzhou District. The oasis area occupies bout 15% of the Minqin Basin, and it belongs to the typical continental desert climate and characterized by aridity, infrequent occurrence of precipitation, violent evaporation, frequent occurrence of strong wind, etc. Entironment in the Minqin Basin is extremely frangible, and the natural vegetation is seriously degenerated due to the serious shortage of water resources. In this study, the Minqni Basin is divided into 4 ecological functional divisions, i.e. the oasis ecological functional division, oasis-marginal ecological functional division, fixed/ semi-fixed dune ecological division and moving-dune ecological functional division. The ecological functions and the actuality of the natural vegetation in all the ecological functional divisions are investigated and analyzed. According to the actuality of water resources and the ecological functions in all the ecological functional divisions in the Minqin Basin, it is suggested to artificially supply water and plant the artificial vegetation in the oasis-marginal ecological functional division. It is estimated that the annual artificially-supplied water volume for regenerating the vegetation in the ecological functional division is 1.2 × 10^8 m^3.