扎龙湿地生态环境需水量安全阈值的研究

Safety threshold of eco-environmental water requirement in wetland

在湿地生态环境需水量概念内涵剖析的基础上,将生态环境需水量分为存量(蓄水量)与通量(耗水量)两个部分。提出了基于生态水面法的湿地生态环境需水量计算模型。应用该方法对扎龙湿地长序列水面面积数据进行了频率分析,再与湿地生态系统健康状况对照分析,确定生态水面系数,得出湿地生态环境需水量安全阈值。安全阈值分为:最小、中等、理想三个级别,分别计算全年月均最小存量、中等存量和理想存量;全年最小通量、中等通量和理想通量,并分别给出了逐月需水过程。分析计算结果表明,扎龙湿地生态环境需水量变化过程符合当地的自然水文变化规律。

According to the connotation, the eco-environmental water requirement can be divided into two parts： water storage and water consumption. A model for determining the eco-environmental water requirement based on water area method is suggested and applied to analyze the situation in Zhalong Wetland. The ecological water area coefficient is determined according to the analysis on the amount of water area in a long time series and comparison with the health situation of the eco-system. On this basis the safety threshold of eco-environmental water requirement can be obtained in terms of three grades： minimum, medium and ideal. The monthly average minimum water storage, medium water storage and ideal water storage as well as the minimum water consumption, medium water consumption and ideal water consumption are calculated. The processes of monthly water requirements are obtained accordingly. The result shows that the variation of eco-environmental water requirement accords with the natural hydrology condition in this wetland.