本文選題：EFDC模型 + 水動(dòng)力�。� 參考：《浙江大學(xué)》2017年碩士論文

【摘要】：滇池是我國(guó)西南地區(qū)的第一大淡水湖,其發(fā)展?fàn)顩r與昆明市的發(fā)展息息相關(guān)。湖泊的水動(dòng)力過(guò)程是水環(huán)境研究的基礎(chǔ)。本文以2014年的數(shù)據(jù)為基礎(chǔ),利用EFDC建立滇池外海水動(dòng)力模型,對(duì)滇池外海的流場(chǎng)、水溫、水位、污染物的遷移擴(kuò)散等進(jìn)行模擬,結(jié)果如下:1)對(duì)比二維水動(dòng)力模型和三維水動(dòng)力模型的風(fēng)生流模擬結(jié)果,發(fā)現(xiàn)三維水動(dòng)力模型模擬四層以上結(jié)果趨于收斂,其模擬結(jié)果更合理。2)滇池外海的流場(chǎng)在絕大部分區(qū)域內(nèi)受風(fēng)的驅(qū)動(dòng)影響,在河口位置受河流的驅(qū)動(dòng)影響。受常年西南風(fēng)的作用,滇池外海流場(chǎng)以逆時(shí)針?lè)较虻沫h(huán)流為主。滇池外海相對(duì)水位(滇池實(shí)際水位=相對(duì)水位+1871.5m)常年保持在14.9m左右。春季水位較高,可達(dá)15.1m。在夏季和秋季水位較低,最低可達(dá)14.7m。影響滇池水位變化的因素主要是出入湖流量。風(fēng)對(duì)湖泊的流場(chǎng)和水位影響較大,風(fēng)向的變化會(huì)引起湖水流向和湖體水位分布的變化。風(fēng)速的變化則會(huì)引起湖體流場(chǎng)的流速和最大水位差的變化。3)滇池常年平均水溫在16℃左右,最高水溫在25℃左右。影響湖體溫度變化的敏感參數(shù)主要是對(duì)流熱傳遞相關(guān)系數(shù)RCHC和蒸發(fā)熱傳遞相關(guān)系數(shù)REVC。滇池表層水溫和底層水溫之間存在分層現(xiàn)象,且最大溫度梯度可達(dá)1.1℃/m,分層現(xiàn)象在夏秋兩季較為明顯。4)在滇池外海,污染物的遷移擴(kuò)散路徑主要與湖體流場(chǎng)有關(guān),同時(shí)存在橫向擴(kuò)散。在設(shè)置三種降解速率的降解系數(shù)后,污染物的遷移擴(kuò)散范圍基本一致,但污染物的衰減和降解系數(shù)關(guān)系較大。通過(guò)對(duì)滇池外海進(jìn)行水動(dòng)力模擬發(fā)現(xiàn):水位和流場(chǎng)是湖體的水動(dòng)力過(guò)程中最重要的兩個(gè)因素。外界的風(fēng)對(duì)水位和流場(chǎng)的變化影響較大。通過(guò)全面了解滇池外海的水動(dòng)力過(guò)程、溫度變化、物質(zhì)的遷移轉(zhuǎn)化規(guī)律等,為今后的泥沙和水質(zhì)研究提供理論支持。
[Abstract]:Dianchi Lake is the largest freshwater lake in southwest China, and its development is closely related to the development of Kunming City. The hydrodynamic process of lakes is the basis of the study of water environment. Based on the data of 2014, the hydrodynamic model of Dianchi Lake is established by using EFDC, and the flow field, water temperature, water level, pollutant migration and diffusion are simulated. The results are as follows: (1) comparing the results of wind induced flow simulation between two dimensional hydrodynamic model and three dimensional hydrodynamic model, it is found that the simulation results of three dimensional hydrodynamic model tend to converge over four layers. The simulation results are more reasonable. 2) the current field outside Dianchi Lake is driven by wind in most areas and by rivers in estuaries. Due to the effect of the annual southwest wind, the current field of the Dianchi Lake is dominated by the counter-clockwise circulation. The relative water level of Dianchi Lake (actual water level = relative water level of Dianchi Lake 1871. 5m) is kept at about 14. 9m all year round. The spring water level is relatively high, reaching 15.1m. The water level is lower in summer and autumn, and the lowest level is 14.7 m. The main factor influencing the water level of Dianchi Lake is the discharge of the lake. The wind has a great influence on the flow field and water level of the lake, and the change of wind direction will cause the change of the water flow direction and the water level distribution of the lake body. The variation of wind speed will cause the change of flow velocity and maximum water level difference of lake body. 3) the annual average water temperature of Dianchi Lake is about 16 鈩，

本文編號(hào)：1957798