风场和吞吐流对洪泽湖流场的影响分析

Effects of wind field and throughput flow on the flow field of Hongze Lake

采用MIKE21建立洪泽湖二维水动力数学模型,通过对模型参数的率定,使得模型的计算结果能较好地与实测值相符合,进而研究了不同风场和吞吐流条件下的洪泽湖水动力特性,比较了2013年洪泽湖在5、10 m/s风速和无风条件下的流场。结果表明:风速会改变流场强度的大小而不会改变流场结构;同时,风场的作用会影响洪泽湖的出流能力,湖区流速随风速的增加呈减小的趋势。吞吐流是影响洪泽湖流场的主要因素,采用2007洪水年进行模拟时,进出口湖区流场会发生明显改变。洪泽湖的溧河洼区和成子湖区流场结构主要由风场决定,而南部湖区和东部湖区流场结构由风场和吞吐流共同决定,且以吞吐流为主。研究结果可以为洪泽湖物质输移规律研究提供理论基础。

MIKE21 was used to establish a two-dimensional hydrodynamic mathematical model of Hongze Lake.By calibrating the model parameters,the calculated results of the model agreed well with the measured values,and then the hydrodynamic characteristics of Hongze Lake under different wind fields and throughput flow conditions were studied.We compared the flow field of Hongze Lake in 2013 under the wind speed of 0 m/s,5 m/s and 10 m/s,respectively.The results showed that the wind speed would change the intensity of the flow field but not the structure of the flow field.In addition,the effect of wind field would affect the outflow capacity of Hongze Lake,and the flow velocity of the lake area decreased with the increase of the wind speed.The throughput flow was the main factor affecting the flow field of Hongze Lake.The flow field of the inlet and outlet lakes changed significantly when the 2007 flood was used for simulation.The flow field structures in the Li River Basin and Chengzi Lake area of Hongze Lake were mainly determined by the wind field,whereas the flow field structures in the southern and eastern lakes were determined by both the wind field and the throughput flow,with the latter as the dominant factor.The results can provide a theoretical basis for the study of the material transport law in Hongze Lake.