海平面上升背景下辐射沙脊风暴潮增水研究

海平面上升将对沿海环境构成严重威胁,风暴潮灾害频发和加剧是其中的重要表现。相关研究揭示水深和潮波变化是引起风暴潮增水与海平面上升之间非线性关系的两大主要因素。在地形和潮波系统较为复杂的苏北辐射沙脊海域这种非线性关系尤为明显。总结了该海域潮波、风暴潮特征和海平面变化趋势,利用WRF模式和Delft 3D风暴潮模式相结合,建立了东中国海和南黄海二维天文潮-风暴潮耦合数学模型。分析研究了海平面上升以后,相同路径和强度的两种典型台风作用下,辐射沙脊海域风暴增水极值和高潮位变化。分析结果表明:海平面上升后,辐射沙脊海域增水作用普遍减弱,近岸较外海明显;而在辐射沙脊中、南部,海平面上升对天文潮高潮位的增强作用要强于对风暴增水的减弱作用。

A study of storm surge in radial sand ridges under sea level rising

Sea level rise would result in a serious threat to the coastal environment， and an important factor is the intensifying and increasing frequency of the storm surge. The relationship between storm surge and sea level rise is not linear according to related studies. The variations of tidal waves and water depth are found to be the two main causes. Radial sand ridges off the north Jiangsu are a particularly interesting area for studying this nonlinear interaction， as there exist a complex large geomorphic system and an astronomic tidal system. The paper summarizes the tide and storm surge characteristics in radial sand ridges， as well as the trend of sea level change. Then a two-dimensional coupled model of astronomic tide and storm surge is established for the East China Sea and the South Yellow Sea， by use of WRF model and Delft 3D storm surge model. The distributions of the maximum water level set-up and the high level change when sea level rises are analyzed， under the effects of two typical typhoons which have the same path and intensity. The analysis results show that the water level set-up decreases universally in the radial sand ridges when the sea level rises， and it is more significant at near shore than the open sea. While in the middle and south radial sand ridges， the enhancement of the astronomical high tide level caused by the sea level rising is stronger than the attenuation of sea level rising by the storm surge.