Method for determining ecological flow threshold of urban river channel

Abstract

The invention discloses a method for determining the maximum ecological flow threshold of a river channel. The method includes the steps that long-sequence day runoff data of a representative station in the to-be-determined river channel is selected to extract a mutation point, and a demarcation point of a selected time period in a long sequence is determined; ecological environment flow component index analysis is conducted by utilizing the EFCs method, the change degrees of each flow component in different periods are determined, and influence flow components of the river ecosystem are identified; the tolerance flow rate of characteristic fishes in the to-be-determined river channel and the section parameters of the river channel in different periods are selected, river channel section parameters in good historical ecological periods and the influence flow components under different flow grades serve as constraint conditions for controlling the river ecosystem, the constraint conditions are introduced into a current river channel section, and the ecological flow threshold under the current river channel section is calculated. Calculation results are accurate.

Description

technical field [0001] The invention relates to a method for determining the ecological flow threshold of an urban river. Background technique [0002] As an important part of urban ecological civilization, rivers have attracted more and more attention to their ecological conditions. However, due to the rapid development of urbanization, human activities have had a greater impact on the physical structure, hydrological regime and ecological environment of urban rivers. The hydrological regime of a river is the core of river ecology research, which determines and affects the material cycle, energy process, physical habitat condition and biological interaction of the river ecosystem. At the same time, in the process of urbanization, in order to meet the needs of urban development, urban rivers are different from natural rivers in terms of shape, function and space. Urban rivers are less meandering and have a single cross-section; channelization and lining are serious. The ma...

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Problems solved by technology

[0003] At present, many studies have been carried out on the hydrological situation of the river. Zhang Hongbo et al. applied the range of variability method to study the influence of Baoji Gorge water diversion on the hydrological law and ecological system of the Weihe River. , which seriously hindered the realization of the ecological function of the river; taking the Niqu River as an example, Shu Chang et al. proposed a method to calculate the ecological flow value using the difference between the mean value and the variability hydrological regime threshold value, which provides support for maintaining a healthy river ecosystem; Dai Xiang According to the ecological significance of different flow forms, Qian et al. divided the ecological flow spectrum in the Chaobai River area into five levels, analyzed the flow spectrum in the two periods, and proposed corresponding ecological protection measures

[0004] However, the above-mentioned studies all focus on the hydrological regime of natural rivers and calculate the minimum ecological flow of rivers. However, there are few studies on the evolution of hydrological regimes and ecological flow thresholds of urban rivers affected by water replenishment and external transfer, which is not conducive to urban river hydrology. Situation Restoration and Ecological Governance

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