Effect Of Water Environment In The Sanjiang Plain Based On Different Agricultural Water Resources Structure

The agricultural irrigation water in the hinterland of Sanjiang plain is still dominated by groundwater,and the water consumption is great,and agricultural irrigation and urban water supply are facing water shortage.In order to solve the water problem in the hinterland of sanjiang plain,It is necessary to plan and construct the water diversion and resources allocation project.After the completion of the project,the time and space distribution of water change and the change of agricultural water structure will have an impact on the regional water environment.This paper focuses on the influence of the water environment before and after the implementation of the water diversion and resources allocation project in Sanjiang plain.Firstly,the relationship between distribution of agricultural water resources and water environment effect is analyzed.Secondly,after collecting and organizing the information of the current water environment,the hydrology regime model and the surface water environmental quality model were constructed based on the experiment of farmland community.Then,the changes of the hydrological situation and the pollution load of the Sanjiang plain were analyzed and predicted,and the water quality forecast was carried out in the downstream of Songhua river and the Naoli river basin.Prediction of the hydrological situation before and after the allocation of water,results show that: The water diversion project has a slight influence on the hydrology regime of the main stream of Songhua river.However,due to the period of may ~ August are in the wet water,it can alleviate the adverse effect of water diversion on the decrease of water volume in the downstream reaches of the Songhua river.Through the diversion of Songhua river’s rich transit water resources,the project implementation has little effect on the ecological water consumption of the Naoli river.The prediction results of surface water environment are indicated: With the progress of sludge wastewater treatment process,industrial and urban sewage ammonia nitrogen emissions were significantly reduced in the trend of rural non-point source pollution emissions into the river and also with less population change.Due to the increase in the area of paddy field after the allocation of water diversion,the amount of runoff pollutant and the amount of river inflow in the planned horizontal annual water field will be increased by the year 2030.Section on the lower reaches of Songhua river water quality 5 ~ 8 month almost no change,can satisfy Ⅲ class quality goals.Flexure river each section 5 ~ 8 month the concentration of ammonia nitrogen,total phosphorus and total nitrogen were increased,the overall did not change the status quo of surface water Ⅲ class water quality.Finally,it summarizes the influence of agricultural water resource allocation on water environment effect,and puts forward water environment protection measures to provide scientific basis for sustainable development of agricultural water in Sanjiang plain.