Impact Of Sea Level Rise On Storm Surge And Wave In The Pearl River Estuary

Sea level rise (SLR) has been a serious environmental problem worldwide principally due to the climate change and human activity. The sea level has risen 10cm to 25cm in the past 100 years because of melting glaciers and ocean expansion with rising temperature. According to the studies, the sea level rise is accelerating.The Pearl River Estuary (PRE) is a subtropical estuary located in the south of the Tropic of Cancer. It has eight inlets, which discharge into the South China Sea. The Pearl River Delta has become one of the richest parts of China with rapid population and economic development and it is one of the most fragile regions with storm surge. Considering the importance of PRE, the research on variations of water levels under the influence of SLR will be meaningful and necessary. Hence, the ADCIRC+SWAN coupled model forced by tides and river discharges is used in simulating the variations of storm surge and wind wave under the influence of SLR. The main contents and results are as follows:1. A high-resolution ADCIRC model is employed to simulate the tidal level in the Pearl River Estuary. The ADCIRC model is validated by comparing simulated values with field data and the results reach an agreement in terms of tidal range and phase. Coupled with Jelesnianski circle wind model, the ADCIRC+SWAN model is applied to simulate storm surge and wind wave during the process of typhoon. The validation results show that the storm surge and wave height match well with the observed data. It indicates the model simulates the hydrodynamic processes well and the model can be used in further study to predict the water levels and wind wave under the influence of sea level rise.2. In order to analyze the potential impacts of SLR on the water levels and wind wave, the basic scenario is compared with other two future scenarios with 0.5-m and 1.0-m of SLR. It can be seen, the sea level rise has more effects on the shallow water areas than deep water regions. The increasing amplitude of water levels respond to the sea level rise is spatially non-uniform. The wave heights in the shallow water areas are more sensitive to SLR and the variations are consistent with SLR.3. The potential impact of hurricane intensity on typhoon surge and waves in the Pearl River Estuary are investigated using the ADCIRC+SWAN coupled model. The results show that the water levels are sensitive to hurricane intensity in the shallow areas and wave heights generally increase with different hurricane intensity cases.4. The study implements the impacts of SLR and hurricane intensity increase in terms of intensified surge heights. With SLR and intensified surge conditions, the wave heights will be higher and this is alarming to people in the Pearl River Estuary. The outcomes of the present research would set a firm basis for policy and decision makers for future shelter planning and designing safe shelter heights.