基于EFDC模型的小浪底水库水温研究

摘要

In order to reduce negative effects on the downstream agricultural production and aquatic lives due to low-temperature water discharging from Xiaolangdi Reservoir,it is important to accurately predict the stratified water temperature distributions before the high dam.In this paper,the water temperature model of Xiaolangdi Reservoir was established by using the EFDC model and simulated in three typical hydrological years.The simulation results showed that the water temperature stratification in the reservoir area under the three conditions was not obvious in November,December,January,February and March,and the difference between the upper and lower water temperatures was within 1 ℃.From April to October the water temperature in the reservoir was obviously stratified,and the variation of the water temperature in the lower layer was smaller than that of the upper layer.Especially in July,the difference between the upper and lower layers was almost 12 ℃.Xiaolangdi Reservoir has a good water temperature stratification after completion,and the water temperature gradually decreases with the increase of water depth.The results showed that the EFDC model is ideal for simulating the water temperature stratification in front of the dam.%准确预测小浪底水库的坝前水温分布对减免水库下泄低温水对下游灌区农作物和水生生态环境造成不利影响有重要意义.利用EFDC模型建立了小浪底水库水温模型,分3种工况(丰水年、平水年、枯水年)对小浪底水库水温进行模拟.模拟结果表明,3种工况下库区坝前水温在11月、12月、1月、2月、3月无明显分层现象,上下层水温相差在1℃之内;4月至10月水库水温出现分层现象,上层年内变幅大,下层年内变幅小;尤其7月份,上下层水温相差可达到l2℃左右;小浪底水库建成后垂向有较好的水温分层,水温随着水深的增加逐渐降低.将模拟计算的水温结果与实测水温值进行对比分析,结果表明,EFDC模型用来模拟库区坝前水体的水温分层情况比较理想.