SHANG Wenxiu, PENG Shaoming, WANG Yu, ZHENG Xiaokang, WU Jian, LIU Baijun

Abstract: Providing appropriate environmental flow regime is important to maintain river health and support the development of human society. Despite the clear physical mechanism and wide application of the habitat simulation method, the accuracy of which is often questioned due to insufficient indicator species and ignorance of life rhythm signals. In order to maintain the native ecological integrity of the riverine ecosystem, the natural flow regime is taken as the hydrological reference system to develop an ecological integrity-oriented environmental flow regime assessment method by coupling habitat simulation with characteristic values of hydrological reference system. This method can ensure the survival and reproduction and indicator species and the survival of native biocommunity. The assessment results of Lijin in the Lowe Yellow River show that the minimum annual environmental flow requirement in Lijin is 11.9×109 m3; the suitable environmental flow requirement in Lijin is 13.0×109 m3~13.7×109 m3; 1~2 high flow pules which last more than 7d and more than 1220 m3/s need to be provided in the rising water season. By comparing the historical measured flow data and the environmental flow demand results in this paper, the total water volume is sufficient but the flow process could not satisfy the environmental flow regime requirement in Lijin. Therefore, it is necessary to enhance the reservoir group intra-annual and inter-annual regulation to provide appropriate environmental flow regime and create high flow pulses in suitable time.

Keywords: ecological integrity; environmental flow regime; habitat simulation; ecological habit; hydrological reference system