Rivers in the Liaohe River Estuary area have been seriously polluted by discharges of wastewater containing petroleum pol- lutants and nutrients. In this paper, The Enhanced Stream Water Quality Model （QUAL2K） and i...Rivers in the Liaohe River Estuary area have been seriously polluted by discharges of wastewater containing petroleum pol- lutants and nutrients. In this paper, The Enhanced Stream Water Quality Model （QUAL2K） and its revised model as well as One-dimensional Tide Mean Model （1D model） were applied to predict and assess the water quality of the tidal fiver reach of the Liaohe River Estuary. Dissolved oxygen （DO）, biochemical oxygen demand （BODs）, ammonia nitrogen （NH3-N） and total phosphorus （TP） were chosen as water quality indices in the two model simulations. The modelled results show that the major reasons for degraded rivers remain petroleum and non-point source pollution. Tidal water also has a critical effect on the variation of water quality. The sensitivity analysis identifies that flow rate, point load and diffuse load are the most sensitive parameters for the four water quality indices in the revised QUAL2K simulation. Uncertainty analysis based on a Monte Carlo simulation gives the probability distribution of the four wa- ter quality indices at two locations （6.50 km and 44.84 km from the river mouth）. The statistical outcomes indicate that the observed data fall within the 90% confidence intervals at all sites measured, and show that the revised QUAL2K gives better results in simulating the water quality of a tidal fiver.展开更多
This paper describes the development and application of a new mathematical technique to include stochasticity in environmental models. The techniques are studied to develop stochastic analysis model of the CBOD NBOD D...This paper describes the development and application of a new mathematical technique to include stochasticity in environmental models. The techniques are studied to develop stochastic analysis model of the CBOD NBOD DO equations for predicting the river water quality. The CBOD NBOD DO equations are expanded to include stochastic terms. Stochastic terms are separated from non fluctuating terms, and the resulting set of equations is solved simultaneously. Solutions are used to calculating the integral solutions and the distribution moments of the state variables. The moments are used in conjunction with the Fokker Planck equation to produce an analytical solution for the probability density functions of the dependent variables. Because the approach produces analytical solutions, it offers greater flexibility than a Monte Carlo approach in treating complex environmental situations. The model is used to calculate water quality for the Qingao river. The calculated results are in good agreement with the Monte Carlo model and field data.展开更多
基金Under the auspices of Water Pollution Control and Management Key Project of Science and Technology of China(No.2013ZX07202-007)Liaoning Hundred-Thousand-Ten Thousand Talents Program
文摘Rivers in the Liaohe River Estuary area have been seriously polluted by discharges of wastewater containing petroleum pol- lutants and nutrients. In this paper, The Enhanced Stream Water Quality Model （QUAL2K） and its revised model as well as One-dimensional Tide Mean Model （1D model） were applied to predict and assess the water quality of the tidal fiver reach of the Liaohe River Estuary. Dissolved oxygen （DO）, biochemical oxygen demand （BODs）, ammonia nitrogen （NH3-N） and total phosphorus （TP） were chosen as water quality indices in the two model simulations. The modelled results show that the major reasons for degraded rivers remain petroleum and non-point source pollution. Tidal water also has a critical effect on the variation of water quality. The sensitivity analysis identifies that flow rate, point load and diffuse load are the most sensitive parameters for the four water quality indices in the revised QUAL2K simulation. Uncertainty analysis based on a Monte Carlo simulation gives the probability distribution of the four wa- ter quality indices at two locations （6.50 km and 44.84 km from the river mouth）. The statistical outcomes indicate that the observed data fall within the 90% confidence intervals at all sites measured, and show that the revised QUAL2K gives better results in simulating the water quality of a tidal fiver.
文摘This paper describes the development and application of a new mathematical technique to include stochasticity in environmental models. The techniques are studied to develop stochastic analysis model of the CBOD NBOD DO equations for predicting the river water quality. The CBOD NBOD DO equations are expanded to include stochastic terms. Stochastic terms are separated from non fluctuating terms, and the resulting set of equations is solved simultaneously. Solutions are used to calculating the integral solutions and the distribution moments of the state variables. The moments are used in conjunction with the Fokker Planck equation to produce an analytical solution for the probability density functions of the dependent variables. Because the approach produces analytical solutions, it offers greater flexibility than a Monte Carlo approach in treating complex environmental situations. The model is used to calculate water quality for the Qingao river. The calculated results are in good agreement with the Monte Carlo model and field data.
