Coupled Modeling Of Surface Water And Groundwater In Shayinghe River Basin

Exchange between surface water bodies like rivers and groundwater is animportant part of the water cycle, which is a key foundation for study onregional water resources and water environment.According to the hydrological characteristics of the major river of the studyarea, study on the interact between the Shayinghe River and Ci River withgroundwater systems was ensured as core study of the interaction of ShayingheRiver of Anhui Province with groundwater system (the Shayinghe main streamfrom Jieshou to Fuyang, and Ci River basin),on the basis of this, build the riversand groundwater hydraulics coupled numerical simulation model was establishedwith Visual MODFLOW calculation software, the simulation model was identifiedand verified with the series of observational data from five diving dynamicobservation wells in the study area, then, exchange between groundwater and riverwater was evaluated with Zone Budget subroutine package.Base on the above research, the effect of groundwater discharge on river waterquality in the dry season was valued by the mixing diluted diffusion model, apossible negative impact of Shayinghe River on surrounding underground waterquality was briefly analyzed.Riverbed hydraulic conductivity is an important factor in the exchangebetween surface water and groundwater and the most critical issue is thedetermination of the riverbed sediment permeability coefficient. In view of generalphenomenon of river sedimentation because of gate control, the riverbed sedimentwas considered in the study of exchange between rivers and groundwater. Field insitu testing, the riverbed sediment distribution and hydrogeology parameters wereobtained, and were reflected as a relatively independent formation in thehydrogeological model.The results show:1. The relationship between rivers in the study area (Jieshou to Fuyang sectionof Shayinghe River main stream, as well as the Ci River) with groundwater mainlyexpressed as groundwater excretion to rivers, intensity are bigger especially in thedry season. 2. Deposition law is complex in riverbed sediment of Shayinghe River, there isa large variation in sediment permeability coefficient in the different sections of thesame river, which is generally between0.006m/d to0.08m/d.3. The intensity of groundwater discharge to river flow is influenced by theriverbed sediment permeability coefficient, without regard to the riverbed sediment,the strength of groundwater discharge to Shayinghe River is two times as thestrength with regard to the riverbed sediment.4. The strength of groundwater discharge to rivers is large in the dry season atthe study area, accounting for39%of the low flow, there were significantimprovements to water quality of rivers of groundwater discharge rivers in the dryseason, while the river has little impact on the surrounding groundwater quality.