Study On Overall Control Goal Of Total Nitrogen Of Agricultural Non-point Pollution Dominant River Basin Based On BMPs

To determine the overall control goal of water contaminant of agriculturalnon-point pollution dominant river basin during the 12thFive Years Development,taking water catchment of Stone Kou Men reservoir as an example, this thesis is tobuild ReNuMa pollution load model, carry out the analysis of the total nitrogenfeature of in divided period, area and source; according to the predict of populationscale, point source discharge of basin's planned year (2020), this thesis is to buildReNuMa model in this year; based on the model's parameter sensitivity and basin'swater quality goal in 2020, the thesis is to select 6 BMPs(Best Management Practice)to be implemented during the planned period (2010-2020);aiming at achieving themaximum between economic benefits, environment and social returns and usingmulti-goals optimized methods, this thesis is to optimize and integrate above 6 BMPsto obtain the implemented ratio of each BMP in the basin; this thesis is to build thebasin's overall control goal model based on water control and pollution sourcemanagement, put the reduced quantity of total nitrogen after implementing integratedBMPs into overall control goal determination and advance overall control goal of totalnitrogen (point source and non-point source) in 2020 and then assign the goal tovarious areas and towns. The achievements of this thesis is advanced as belows.(1) Based on successive monthly monitoring data of longlasting supervised waterquality in hydrology of Stone Kou Men reservoir, both surface runoff Ensandsimulation accuracy of total nitrogen R2are above 0.6. The simulation accuracysatisfies the management demand of water environment of large and middle sizedbasin; according to the predict of population scale, point source discharge of basin'splanned year (2020), this thesis is to build ReNuMa model which becomes a majortool of overall control goal of basin's BMPs optimized integration and basin's totalnitrogen.(2) According to ReNuMa model's sensitivity parameters and basin's waterquality goal in planned year, the thesis is to select 6 BMPs to be implemented duringthe planned period (2010-2020); the thesis is to formulate program of each BMPdirecting at the key source areas of cultivated land, lawn and rural residential area, i.e.to control the pollution arising from the cultivated lands by implementing 4 BMPs, i.e."carrying out returning cultivated lands to forests","building equal-heighted plantsfence","promoting the method of little cultivation"and"controlling application levels of nitrogen fertilizer", to control the pollution arising from grass land by"carrying out returning grass to forest", to control the pollution arising from ruralresidential area by"promoting rural biogas plants".(3) Aiming at achieving the maximum between economic benefits, environmentand social returns, this thesis is to build BMPs optimized and integrated model in thebasin and solve the model by genetic algorithm under Matlab software environment,and thus obtaining the implemented ratio of 6 BMPs in the basin, i.e. 99.97%,13.82%,99.98%,99.99% ,0.05%,99.99%.(4) Aming at the combination of basin's water quality management and pollutionsource management, the thesis is to build basin's overall control goal model anddetermine 24.8 thousand tons as overall control goal of the total nitrogen (includingpoint source and non-point source) of the basin after implementing integrated BMPsin the planned year; this thesis is to build the decision model of regional overalldistribution layers and determine the overall control goal of total nitrogen in theplanned year in places, i.e. 9.7 thousand tons to Shuangyang District, 5.9 thousandtons to Yongji County and 9.2 thousand tons to Panshi City.