【摘要】：為研究三峽水庫運行以來鹽水入侵對長江河口的影響,采用自行編譯完成的Delft3D 4.01.01版本源代碼,建立了大通到長江口外的二維水流鹽度數(shù)學模型,綜合分析入海徑流量與鹽水入侵的響應機制。研究表明Ddlft3D 4.01.01源代碼能很好地模擬計算長江口水動力鹽度分布,驗證誤差僅有10%~15%。從計算結(jié)果可以看出,鹽水入侵情況與徑流量關系明顯,當大通站徑流量為5 000 m~3/s時,長江口南支與北支均發(fā)生鹽水入侵。隨著徑流量增大,淡水區(qū)域面積由南支右岸向下游進一步擴大。當徑流量超過30 000 m~3/s時,南支基本不存在鹽水入侵情況,可以保證水庫正常取水安全。當存在風力作用時,鹽水入侵明顯,鹽水濃度達到3.5 ppt以上,而無風情況下,鹽水入侵趨勢減弱,長江口南支河段區(qū)域的鹽度一般滿足灌溉水的標準(2.2‰)。
[Abstract]:In order to study the influence of saltwater intrusion on the Yangtze River estuary since the three Gorges Reservoir came into operation, a two-dimensional mathematical model of the salinity of water flow from Datong to the Changjiang Estuary was established by using the self-compiled source code of Delft3D version 4.01.01. The response mechanism of runoff into the sea and salt water intrusion is analyzed synthetically. The results show that the source code of Ddlft3D 4.01.01 can well simulate and calculate the distribution of hydrodynamic salinity in the Changjiang Estuary, and the verification error is only 10 / 15. From the calculation results, it can be seen that the salt water intrusion is obviously related to the runoff. When the runoff of Datong station is 5 000 mm3 / s, both the south branch and the north branch of the Changjiang Estuary have saline intrusion. With the increase of runoff, the area of fresh water is further expanded from the right bank of the southern branch to the downstream. When the runoff exceeds 30 000 mm3 / s, there is no salt water intrusion in the southern branch, which can ensure the normal water intake safety of the reservoir. When there is wind force, the salt water intrusion is obvious, the salt water concentration is over 3.5 ppt, but the saltwater intrusion trend is weakened under the condition of no wind, the salinity of the south branch reach of the Yangtze River Estuary generally meets the irrigation water standard (2.2 鈥，

本文編號：2211119