Falls Lake水库内溶解物输运模拟

Numerical study on dissolved matter transport in Falls Lake Reservoir

溶解物在水库内的输运过程受人为因素影响较大。为研究水库内物质输运的过程和机制,以美国北卡罗来纳州的Falls Lake水库为研究对象,运用EFDC三维数值模型对物质在水库内的输运过程进行模拟研究,分析示踪物平均年龄和滞留时间的分布以及变化。结果显示:理想状态下,流量决定溶解物的输运过程;实际情况中,除流量外,水库的即时蓄水量是影响输运过程的另一个重要因素;水库结构和径流分布是导致示踪物在各区域局地滞留时间存在差异的主要因素。

As a consequence of the dam,the physical transport of dissolved matter is profoundly affected by human activities in reservoirs.A three-dimensional numerical model,Environmental Fluid Dynamics Computer Code（EFDC）,is used to study the physical mechanisms of mass transport in the Falls Lake Reservoir in North Carolina,USA.The spatial and temporal variations of the mean age and the residence time of a tracer are analyzed.Under steady-state conditions with constant in-/out-flows,the dissolved matter transport is dominated by river discharges.Under dynamic conditions,the phase of the water storage is also an important factor.The geometric feature and the function of the reservoir and the distribution of the tributary runoffs are the major factors that contribute to the differences of the local residence times.