Coupled Modeling And Application Of Hydrological,Hydrodynamic And Water Quality Models For Typical Coastal Basins

Yongjiang is the mother river of Ningbo.It is one of the eight major river basins in Zhejiang province,located on the eastern coast of Zhejiang and the south of Hangzhou Bay.With the rapid development of Ningbo's economy and population,the problem of water quality and water ecological environment deterioration in Yongjiang River Basin is more prominent,especially in the middle and lower reaches of the river.For the comprehensive management and sustainable development of water environment.The relationship between pollution discharge and water quality response in Yongjiang River Basin requires a scientific understanding of the hydrological cycle and the characteristics of water transfer and transformation in Yongjiang River Basin.The river system of Yongjiang River Basin is composed of mountain rivers,plain rivers and tidal rivers.For such a complex river system,it is urgent to analyze the hydrologic,hydrodynamic and water quality relationship model.The modeling of hydrologica,hydrodynamic and water quality in Yongjiang River Basin requires a combined distributed hydrological model,1-D river hydrodynamic-water quality model and a multi-dimensional hydrodynamic-water quality model to realize the analysis and simulation of the hydrologic process and the water environment in this complex basin.The advantage of multi model coupling is that it can give full play to the advantages of each model,and the key of coupling is information transmission and interaction between computation results of each model.Determination of parameters is a basic work for establishing the water quality model,and the quality control of the continuous measured data is the prerequisite and guarantee for improving the accuracy of the model.The detection of abnormal data in the sequence is realized by using the sliding window technique,the Dixon detection criterion and the unified count lookup table.In order to reconstruct the abnormal data,the weighted interpolation results of normal data sets in the window are used instead of the abnormal values.The experimental results show that the method can effectively detect and reconstruct the abnormal data and fully retain the results of the normal data.On the basis of the existing distributed hydrological model,one dimension hydrodynamic water model and three dimensional hydrodynamic water quality model,this thesis transfers the water and water concentration information of different models through the top-down characteristics of hydrologic process,and realizes the coupling between different models.Under the support of multi-dimensional and multi angle data in Yongjiang River Basin,the quality control of continuous observed hydrological data is realized by using the difference analysis and Dixon detection criterion,and the L-THIA model is used to measure the water yield and surface source load of the river basin,and the hydrodynamics water of the mountain rivers and the plain rivers is realized by QUAL2K.Qualitative analysis,for more complex Yongjiang river water,the EFDC model is adopted for modeling and analysis.Through the calibration and validation of the model,the coupling effect among the models is good.At last,according to the characteristics of the rainfall in Yongjiang River Basin,90%hydrological scenarios of dry year,75%drought year and 50%year are designed.The simulation of water concentration is realized by using the parameter information of the model rate,and the corresponding water environment capacity and pollution capacity are calculated,so as to guide the water environment management,total amount control and pollution in the flow field.It provides a scientific basis for the formulation of dyed cuts.