基于模糊隶属度的白洋淀生态干旱评价函数研究

Ecological drought evaluation function of Baiyangdian based on fuzzy membership degree

针对白洋淀生态环境日趋恶化、生态系统安全受到威胁的现实,通过构建关于渔业产量和芦苇面积2个指标的生态系统健康评价指标体系,计算生态系统健康相对隶属度,进而对生态系统健康相对隶属度与年均水位进行回归分析,结果表明两者呈指数函数关系,函数形式为f(x)=e1.251x-11.712;以此为基础,确定生态干旱评价函数,结合白洋淀历年水位观测资料,分析白洋淀生态干旱演变趋势及主要成因.分析结果表明:白洋淀生态系统呈持续干旱趋势;入淀水量锐减是造成白洋淀干旱的主要原因,虽然多次实施应急生态补水,但并没有从根本上缓解白洋淀生态系统干旱状态.

With regard to the reality of the increasingly deteriorating eco-environment and threatened ecosystem security of the Baiyangdian wetland,an ecosystem health evaluation index system for fishery production and reed areas was established. The relative membership degree of ecosystem health was calculated. The regression analysis for the relative membership degree of ecosystem health and the average annual water level was performed,and they exhibited an exponential function in the form of f（x）=e1.251x-11.712. On this basis,the ecological drought evaluation function was determined. The ecological drought evolution trend and the main causes of deterioration of the Baiyangdian wetland were analyzed according to observed water levels in past years. The results show that the ecosystem of the Baiyangdian wetland has a trend of continuous drought. The main reason lies in the sharp decrease in the quantity of water flowing into Baiyangdian. The drought of the Baiyangdian ecosystem has not been fundamentally relieved despite much supplementation of ecological water.