Study On Flow Field And Water Temperature Distribution In Dahuofang Reservoir

Dahuofang Reservoir is located in the east of Fushun, Liaoning Province. It is one of the key water-control projects which are mainly for flood control, irrigation, power generation, fish and so on. It is important to study hydraulic characteristics of Dahuofang reservoir as well as the analysis of flow and temperature field in each period, which is also the main objective of this paper.This paper had developed a three-dimensional hydrodynamic model of Dahuofang reservoir based on the unstructured grid of MIKE3, considering wind, the surface heat flux and various factors such as river discharge. The model was calibrated through comparison of simulated and observed surface elevation and temperature.After the validation of the hydrodynamic model, we firstly analyzed the effects of wind field and river discharge on reservoir flow field structure.Results showed that wind is the main factor affecting the flow field structure of Dahuofang reservoir, and its effect on surface water flow velocity is larger than bottom layer. Furthermore, it will result in a compensation flow at the middle and bottom layer of reservoir, and throughput flow resulted from river discharge has unconspicuous influence on the flow structure within the reservoir area.The temperature field analysis of the results showed that Dahuofang reservoir is one of the water temperature stratification reservoirs. During the summer, the water temperature of Dahuofang reservoir is in a state of stable stratification. After entering autumn, the surface and bottom temperature are basically the same. From horizontal distribution of temperature, water temperature in spring from upstream to the area in the front of the dam shows degressive trend. During the period of autumn, the water temperature of reservoir increases from the upstream to the area in the front of the dam. Analysis results of the water temperature numerical experiment showed that the wind will strengthen the water exchange between surface water layer and the lower, resulting in a decrease in suface water temperature and rise in bottom water temperature. The increase of river discharge can make the reservoir surface and bottom water temperature rise at the same time, weakening the temperature stratification to a certain extent.