Validation of the Hypothesis on Water Environmental Capacity of Yinghe River under Different Design Hydrological Conditions

Abstract

The water environmental capacity (WEC) in northern rivers has obvious temporal dynamic characteristics because of the seasonal change, so the calculated WEC under a single hydrological designed condition cannot reflect these changes. In this paper, one-dimensional WEC model is used to calculate the pollutant carrying capacity under three different design hydrological conditions of the Yinghe River, which belongs to Yellow River Basin. The results show that: The COD and NH3-N capacity under the staging design condition are increased 7.15% and 9.75% compared with the conventional method; the COD and NH3-N capacity of average monthly flow condition are increased 4.89% and 6.35% compared with the conventional methods; the calculation of the stage design condition is closed to the average monthly flow condition, the COD and NH3-N capacity are increased only 2.14% and 3.20% respectively. Comparing the calculation results under different design hydrological conditions, it is found that the results under the conditions of considering the dynamic characteristics can reflect the actual change law of WEC more accurately and effectively. This research has a guiding significance for realizing the total distribution and seasonal utilization of WEC in the Yinghe River.