蒲河流域生态环境需水研究

AN ASSESSMENT ON THE ENVIRONMENTAL WATER FLOW REQUIREMENT OF THE PU RIVER

以蒲河流域为例,以改善水环境为出发点,提出了一种以生态分区为前提,同时满足人类正常生产活动的生态环境需水估算模型。该模型从生态系统角度分析了蒲河流域现阶段存在的问题,比简单的水文模型更为符合蒲河流域的实际特点。在此基础上对蒲河流域进行生态分区,针对各生态分区对生态需水的需求不同,分别估算需水值。其中包括河道基本生态需水、河道蒸发需水,河道渗漏需水等。在考虑生态需求的同时,针对蒲河季节性河流且人工干扰严重的特点,对蒲河流域生态需水量值进行估算。计算结果表明,蒲河流域生态需水总量为4 538.46万m3,并具有年内变化显著、受人类活动(污水排放量、人口密度等)影响各分区差距显著等特点,研究成果为今后季节性河流需水量的研究提供了依据。

The environmental impact of flow alterations has emerged as an important aspect of river management.However it is often difficult to find a single indicator linking the flow regime to the sustainability of the riverine ecosystem.So,this paper proposes an integrated method for the instream flow assessment,which includes basic flow requirement,evaporation requirement and seepage requirement. There are three innovative features in this study.(a)The propose of ecological partition solves the previous problem without different ecological requirement in the riverine.(b)Comparing with the traditional approach,this model involves the influence of the human being by including the emissions of sewage, population density to the river.(c)Aiming at more accurate assessment,the method extends to a larger spatial scale,being helpful for river managers in decision making.As the society development affecting more and more the instream flow,people have to solve the connection between environment and river management.So this paper synthesize ecological demand and activities of human being,with the normal production ecological environment water demand estimation model.The model is based on river flow, rainfall and other hydrological data,combined with the soil conditions of the district environmental water demand estimates.To appropriately take environmental flow requirements into consideration in water resources planning and management,it is required that models used in water resources planning can accommodate the specific characteristics of the environmental flow requirements.Actually activities of human being is the most important factor in the river management,so the indicator includes ecological demand and activities.Then according to the ecological and social life demand,different algorithm can be used in different partition.After introducing the main algorithm,this new algorithm is applied to the Pu River.The results showed that,ecological water requirement amount in the Pu river is 4662.584m3,and the results changed significantly from season to season,being affected by human activities(the emissions of sewage,population density etc.).The results allow for assessment,which includes the high flow pulses and small and large floods that are part of an environmental flow requirement,providing a basis for the study of seasonal rivers.