A method for determining the threshold value of hydrodynamic regulation for improving the water environment of plain urban river network

Abstract

The invention relates to a method for determining the threshold value of hydrodynamic control for the improvement of the river network water environment in plain cities. Based on the mechanism of the bottom flow velocity and shear stress at the mud-water interface, the relationship between the disturbance intensity and the actual river surface velocity is established, and it is proposed to suppress the flow in plain cities. The upper threshold range of hydrodynamic regulation based on the rapid release of river sediment; the minimum water environment capacity theory is adopted for the first time, considering point source pollution, non-point source pollution along the river, dust pollution directly entering the river, release of sediment pollutants, and river water quality. Various factors affecting river water quality, such as self-purification and aquatic plant absorption, were used to derive the formula for calculating the lower threshold of hydrodynamic regulation to improve the urban water environment by using the overall standard method. According to the proposed method for determining the threshold value of hydrodynamic regulation in plain cities, the reasonable flow rate range of actual hydrodynamic regulation in plain cities can be determined, which provides a basis for the reasonable selection of flow velocity in hydrodynamic regulation to improve the water environment, improves the efficiency of water resource utilization, and improves the improvement of the water environment. Effect.

Description

technical field [0001] The invention relates to a theory of hydrodynamic control in the field of water conservancy engineering, in particular to a method for determining a threshold value of hydrodynamic control for improving the water environment of river networks in plain cities. Background technique [0002] Plain cities have developed economy, dense population, high urbanization rate, low terrain, dense river network, and weak hydrodynamic conditions. In recent years, my country is in a period of rapid social and economic development, and the pollution load of rivers continues to increase. Urban rivers are crowded, river networks are divided, water systems are poor, source control and interception are not in place, and water environmental protection measures are lagging behind, resulting in plain cities. The pollution of river network water environment is becoming more and more serious. According to the "Water Environment Quality Bulletin" in recent years, most of the ri...

AI Technical Summary

Problems solved by technology

[0004] In recent years, hydrodynamic control projects have been implemented in the river network areas of plain cities, especially in the Taihu Lake Basin, which has greatly improved the fluidity of regional river water bodies and improved the water environment of some cities. However, due to the current improvement in hydrodynamic control The basic theory of the water environment is not perfect, and there is a lack of hydrodynamic control thresholds to guide the improvement of the water environment. At present, when most plain cities adopt the hydrodynamic control method to improve the water environment, they often adopt the method to adjust the river flow velocity to a reasonable level and how to control the river flow velocity. Trial methods, or judgment based on experience, often lead to fluctuating river flow velocity, repeated changes in flow direction, low utilization rate of water resources, and poor water environment improvement effect

Images