Small and medium-sized river reach assimilative capacity accounting method considering sewage draining exit position influence

Abstract

The invention discloses a small and medium-sized river reach assimilative capacity accounting method considering the influence of the position of a sewage draining exit. The method comprises the following steps: carrying out generalized mapping on calculated small and medium-sized river reaches; according to the generalization graph and pollutant discharge data, determining and calculating the length of the river reach, the distance from a drain outlet to the tail end of the river reach, the sewage discharge flow and the pollutant load capacity of the drain outlet; determining the flow and the average flow velocity of the initial section; according to the empirical pollutant degradation coefficient or empirical formula of the river, determining the attenuation coefficient of the pollutant; determining the pollutant concentration and the water quality target concentration of the initial section; selecting a river reach residual pollutant capacity calculation formula according to the actual condition, and calculating the residual pollutant capacity; and calculating the assimilative capacity of the river reach. According to the method, a traditional assimilative capacity calculation model which neglects the sewage discharge flow and does not consider the influence of the sewage discharge outlet position is improved, and the obtained calculation result of the ecological flow and the assimilative capacity for maintaining the river reach water environment quality has higher precision.

Description

technical field [0001] The invention relates to a method for calculating the pollution-holding capacity of water areas, in particular to a method for calculating the pollution-holding capacity of small and medium-sized river sections considering the influence of the position of the sewage outlet. Background technique [0002] Quantitative accounting of the pollution-carrying capacity of water areas is an important prerequisite for formulating and implementing water pollution control plans, and is also the fundamental basis for the total amount of water pollutants control. Traditionally, the pollution-holding capacity of small and medium-sized rivers is calculated using the one-dimensional model of the river's pollution-holding capacity given in Article A.1.2 of Appendix A of the "Calculation Regulations for the Pollution-Holding Capacity of Water Areas" (GB / T 25173-2010). The model ignores the influence of wastewater discharge flow when calculating the pollutant concentratio...

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Problems solved by technology

The model ignores the influence of wastewater discharge flow when calculating the pollutant concentration of the section at the end of the river. When the discharge flow of wastewater and the initial cross-section flow are greatly different, ignoring the discharge flow of wastewater will reduce the pollution-holding capacity of the river section. If the calculation result is too small, the calculation result of the ecological flow to maintain the water environment quality of the river section will also be too large

Moreover, in the actual calculation, the sewage outlets are usually irregularly distributed on different sections in the river section, and the model does not consider the influence of different sewage outlet locations on the calculation results of the sewage holding capacity of the river section

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