Research On Forecasting Of Water Environmental Pollution Accidents In Drinking Water Source Areas Of Three Gorges Rescrvoir Area

With the rapid development of economy,water environmental accidents occur occasionally,resulting in regional water shortage and huge economic losses.In this context,the issue of water environmental safety has attracted great attention of the whole society,and scientific research institutions as well as relevant scholars have carried out research on water pollution accident forecasting.This study chooses Chongqing section of the Yangtze River in the Three Gorges Reservoir Area as the research area.Through combing the related water environmental accidents and combining the whole process of the accidents,the accident forecasting model of water source areas in the Three Gorges Reservoir Area is constructed,and is embedded into the decision support system for joint operation of Three Gorges and its upstream cascade reservoirs.The model can forecast the water velocity and spatial-temporal distribution of pollutant concentration in water environment,and provide support for decision support system for joint operation of Three Gorges and its upstream cascade reservoirs.It has important practical significance for emergency response of water pollution accidents.The main research contents of which are as follows:(1)Through combing the relevant references on simulation of water pollution accidents at domestic and foreign.After the Chongqing section of the Yangtze River was established as a research area,a database containing hydrological,geological data and water pollution data of river network at all relevant stations in the study area was constructed.The risk source identification and risk analysis were also carried out in the study area.(2)According to the two-dimensional water quantity and water quality model,a model which is suitable for the accident forecasting of water source areas in the Three Gorges Reservoir Area was constructed by using DEM as the computational grid.The results of model verification show that the relative error between the prediction and the measured value is not more than 15%,which is within a reasonable range.Based on the accident forecasting model of drinking water source areas,and the model was embedded into the water source protection module of decision support system for joint operation of Three Gorges and its upstream cascade reservoirs,so as to realize the visual simulation of water pollution accidents in Three Gorges Reservoir Area.(3)The water pollution accident of Chongqing section of the Yangtze River in the Three Gorges Reservoir Area was forecasted by using the decision support system for joint operation of Three Gorges and its upstream cascade reservoirs.Under the same hydrological conditions,the model predicts the spatial-temporal distribution of TP concentration with time in four water periods in the study area under water pollution accidents,The forecast results show that the speed of transport and transformation is flood season>storage period>low water season>dry season.Under different dispatching schemes,the change process of TP concentration at the intake of Huangjuedu drinking water source area in Chongqing section of the Yangtze River was analyzed.It was concluded that increasing the discharge flow from the upstream of the study area could accelerate the migration and diffusion of pollutant mass.The emergency measures of water pollution accidents were studied,and the corresponding emergency measures were put forward.