密云水库水温分布特征

为了分析密云水库近10年来水温分布规律,尤其是1999年以来入流减少对于水温结构的影响,该文在CE-QUAL-R1模型的基础上建立了适用于密云水库的垂向一维水温模型。利用1991和2006年的实测数据对模型进行参数率定和验证,进而模拟1998—2007年水库水温的时空分布。结果表明:在来流减少、水位大幅下降的情况下,密云水库的水温分层现象仍然存在,分层从春夏之交持续到秋季,最大温差超过10℃;当有较大的流量入库时,水库将出现双斜分层的水温结构;随着水位的下降,表层水温变化很小、中层水温上升幅度较大、底层水温上升幅度较小;取水口出流水温随着水位的下降而升高,高水位时最大值出现在秋季,低水位时最大值出现在夏季。

Water temperature distribution in the Miyun Reservoir

A one-dimensional vertical thermal model was developed for the water temperature profiles in the Miyun Reservoir based on the CE-QUAL-R1 model to simulate the temporal and spatial distributions of the water temperatures from 1999 to 2007 during which the inflow into the reservoir decreased and the water level declined significantly.The parameters were calibrated using 1991 data with the simulation results then compared with 2006 data for model verification.The results show that thermal stratification still occurs from the late spring and early summer to the fall.The maximum vertical temperature difference exceeded 10℃.A double-Metalimnion occurred during floods in the summer of 1998.The water level decline has little influence on the temperature distribution for Epilimnion while there is a significant rise for Metalimnion.The water level decline results in a small temperature rise in the bottom layer.The intake water temperature increases as the water level drops.The highest outlet water temperature of the year appears in the fall for high water levels,but in the summer for low water levels.