Study on ecological water demand of the Yellow River estuary | 黄河河口生态需水量研究

Chinese. 针对黄河入海口流量减少导致的河口生态环境破坏、生物多样性降低和生态系统退化问题，研究确定黄河口的生态需水量，为黄河口的生态系统平衡和环境改善、生物多样性维护及生态稳定提供参考。在分析历史文献和调查资料的基础上，进行关键物种的识别，确定食物网中优先保护的序列；分析河口生态系统的限制因子，建立入海径流量与近岸海洋站盐度之间的相关关系；根据优先保护物种的关键生命阶段，用相关分析方法计算黄河河口近海海域不同时期的入海流量和径流量。在近海生态系统中，鱼类是关键物种，和黄鲫为优先保护物种。盐度为河口及附近海域生态系统的限制因子，和黄鲫的优先保护生命阶段为4月、5-6月和7-10月3个阶段，盐度分别为27~31，28~32和27~31。根据黄河入海径流量与盐度的相关关系，确定黄河河口生态需水量约为124亿m3。关键种和关键性指数能够用于生态系统结构比较复杂的河口及附近海域优先保护生物类别的选择，根据关键种占优势的种类以及限制因子盐度，可以计算渤海河口及附近海域的盐度阈值，进而可以确定黄河入海径流量。

English. The decrease of ocean inflow of the Yellow River damages estuary eco-environment, which leads to decrease of biodiversity and degradation of ecosystem. Research on the estuary ecological water demand is very important to the balance of ecosystem, environmental improvement, biodiversity protection and ecological stabilization. In this paper, key species were identified based on historical documents and investigations. At the same time, priority protection sequence in food network was determined. Salinity was determined as limiting factor of estuary ecosystem. Correlation between ocean runoff and salinity of offshore stations was set up. On the basis of key stage of life of priority protection’s species, flow into the sea and runoff were calculated with related calculation method. In offshore ecosystem, fishes are key species, anchovies and carps are priority protection species. Salinity is restriction factor of ecosystem in estuary and adjacent waters, the period of priority protection is April, May-June, July-October, salinity is 27-31, 28-32 and 27-31. On the basis of correlativity between runoff into sea and salinity, the ecological water demand of the Yellow River estuary is 1.24×1010 m3. Key species and key index are used to estuary with complex ecosystem and surrounding waters to select priority protection’s species, on the basis of species whose key species are in the ascendant and restriction factor salinity, salinity threshold is confirmed in Bo sea estuary and surrounding waters, the runoff into sea of the Yellow River is confirmed.