太湖典型风场作用下的水位特征研究

Relation between typical wind and water level distribution in Taihu lake

水位是关系太湖流域水安全问题的核心水动力参数.风场是太湖水位的决定性因素,但是两者间的相互关系尚不明确.本文基于原型观测试验采集的风场和水位数据,分析了SE和NE两种典型风场持续作用24h情况下,太湖6处水位站点的水位分布特征,总结了太湖水位对不同风速的响应关系.研究结果表明:地理位置决定了太湖水位站点的相关性,湖区北部犊山闸站和大浦口站间和南部洞庭西山站、小梅口站和吴溇站间的相关关系均较为显著;SE风向作用下,太湖水位分布特征与风速有关.9m/s风速作用下,太湖水位随风程增加而增加.5m/s左右风速作用下,太湖水位分布特征并不严格符合这一规律;NE风向作用下,太湖水位基本符合随风程增加而增加的规律,水深相同情况下,风速与环湖水位差正相关,风速相同情况下,水深与环湖水位差负相关.

Water level is critical to the flood control,water supply as well as environmental characteristics and ecological attributes of shallow lakes.Wind is the key factor on the determination of water level and yet the relationship between them is not fully illustrated.Therefore,a field observation was conducted in Taihu lake to obtain the typical wind period lasting for 24 hours with directions of SE and NE as well as the synchronous water level data at 6 level stations around the lakes.Based on this the relation between typical wind and water level was estimated.Results indicate that the relevance of water level stations mainly depends on their location.The Maximal information coefficient(MIC)between two stations in the north and three stations in the south are all higher than 0.80.The water level distribution governed by SE wind direction was related with wind speed.When the wind speed equals 9m/s,the water level increases with the increment of fetch,while the trend was opposite with wind speed of 5m/s.The water level distribution governed by NE wind direction rises along with the increment of fetch regardless of wind speed.A positive relation between disparity in water level around the lake is observed with same static water level,while the relation between water depth and disparity in water level becomes negative if the wind speeds are the same.