Research On Multi-source Water Supplement To Ensure Ecological Water Quantity In The Lower Reaches Of Daqing River

Daqing River is a transit river in Wen’an and Bazhou City.It is located in the lower reaches of the Haihe River system.It is an important river ecological corridor in the core area of BeijingTianjin-Hebei and the lower reaches of Xiongan New District,mainly undertake the flood control function of the downstream of Xiongan New District.The water volume of the Daqing River has changed significantly.During the high water period,the water volume is affected by the flood discharge of the upper reaches of Baiyang Lake.The water volume is extremely scarce during the low water period,and some river sections have exposed riverbeds in individual months.At present,the shortage of water resources,the obstruction and exhaustion of the ecological process of the corridor,and the compaction of functions in the Daqing River Ecological Corridor are extremely incompatible with the requirements of regional economic and social development.Therefore,it is urgent to carry out the replenishment of the ecological water volume of the Daqing River.Affected by the flood discharge of the upstream Baiyang Lake,the Daqing River,as a typical artificial river channel,has no obvious hydrological rhythm.During non-flood seasons and part of the flood season,there is no water to flow upstream and downstream of the river,making the determination and realization of the ecological water volume of the Daqing River Basin very difficult.Problems such as water shortage and excessive water quality have seriously affected the function of the Daqing River’s ecological corridor.In order to ensure the water ecological safety in the lower reaches of the Xiongan New District and the ecological water volume of the Daqing River,the paper selects the lower reaches of the Daqing River as the object to find the optimal replenishment path and the coordinated relationship among multiple water sources in different sections of the water sources in the basin.Supplementing the ecological water problem of the Daqing River through reclaimed water,rainwater resources and the amount of water discharged from Baiyang Lake,At the same time,the riverside wetland was constructed to solve the water quality problems under the condition of heterogeneous water source replenishment,and to simulate the hydraulic elements and water quality changes of the Daqing River under different discharge flows of Baiyang Lake,combined with the function of the Daqing River ecological corridor,dynamically optimize the ecological water replenishment process and optimize The reasonable allocation of water resources in the basin provides reference and reference,and then promotes the improvement of the water environment of the Haihe River Basin and its related rivers.The main research contents of the paper are as follows:Study the use of regional reclaimed water and rainwater resources in Wen’an County and Bazhou City to replenish the Daqing River.According to the reclaimed water discharge node of the sewage treatment plant and the relationship between the production and sink of rainfall,on the basis of the MIKE11 model,the hydrodynamic(HD)and water quality modules(AD)are simultaneously coupled to predict and analyze the hydrological and water quality changes of the Daqing River in the supplementary water of heterogeneous water sources.The results show that: in terms of water quantity,the Daqing River can only ensure the river connection in the middle section under the condition of heterogeneous water sources,but there is still the possibility of interruption in the upstream and downstream sections of the river;in terms of water quality,COD and TP are at some points Exceeded standards in part of the month,however,the concentration of ammonia nitrogen from the middle section of the Daqing River to the Taitou section showed a trend of increasing along the way.The ammonia nitrogen concentration in multiple months and at multiple points exceeded 2.0mg/L.The ammonia nitrogen is the water quality of the Daqing River under the condition of heterogeneous water supply.The main overstandard indicators.Multi-source water replenishment research mainly relies on reclaimed water and rainwater from sewage treatment plants as water sources.However,even if the reclaimed water reaches the Class A discharge standard,the content of nitrogen,phosphorus,COD and organic matter in the tail water is still higher than the surface water quality indicators of Class V,especially The ammonia nitrogen content is far from the Grade V water quality standard,and it is difficult to meet the water quality requirements of the Taitou section.In this paper,by arranging the riverside wetlands on both sides of the main channel of the Daqing River,according to the treatment capacity of different aquatic plants for different pollutants,coupling the requirements of the flood control roughness of the Daqing River section,constructing and optimizing the algorithm to be able to deal with the pollution load,and at the same time coupling Riverside wetland with flood control function of Daqing River,that is,on the premise of ensuring that the water quality of the ecological water meets the standard,it can also meet the flood control function of the Daqing River.The research results show that under the conditions of the construction of the riverside wetland,the riverside wetland with three kinds of plants is required to be 1.18km2,and the pollution load brought by the heterogeneous water supply source can be reduced.However,combining the riverside wetland and the evaporation water consumption of the river course,the Daqing River has a complete river course.The annual water shortage is about 10.1914 million tons.It is difficult to ensure the connectivity of the Daqing River and restore the self-purification capacity of the river.It is necessary to rely on the ecological water discharged from Baiyang Lake to replenish the Daqing River,so as to ensure the connectivity of the river and support the construction of the Daqing River ecological corridor.Aiming at the problem that the ecological water volume of the Daqing River is still seriously insufficient under the condition of replenishing water from two heterogeneous sources of reclaimed water and rainwater resources,coupled with the water consumption of the proposed riverside wetland,it is necessary to rely on the ecological water discharged from Baiyang Lake to replenish the Daqing River.At present,in the Daqing River Basin planning,Baiyang Lake’s ecological water supply to the Daqing River is relatively limited.In this study,by simulating the hydrological process of the Daqing River under different ecological water discharges from Baiyang Lake,it predicts and analyzes the hydraulic elements of the Daqing River under different discharge volumes to demonstrate the Daqing River Basin.While planning the rationality of the water discharge volume,according to the ecological water volume,water quality and ecological goals of moderate restoration,seek the most suitable water discharge volume of Baiyang Lake,which meets the water supply of the Daqing River with multiple water sources,and according to the water shortage and water demand of each typical river section Develop a water replenishment plan for the Daqing River under the condition of multiple water sources.