Impact Of Future Condition Variation On Storm Surge In Qiongzhou Strait And Adjacent Waters

Sea level rise,typhoon intensity enhancement,and reclamation are main factors for sea circumstance change in the future,which may impact on storm surge,reducing prevention ability of seawall and revetment,threatening the safety of life and property along the coast.Sea level rise,typhoon intensity caused by climate warming has strong effect on large area,while reclamation only impact on the area around it.Qiongzhou strait locates between Guangdong and Hainan province,which is vulnerable to storm surges,due to its unique geographical location.Under the background of global warming and reclamation,it is urgent to assess the impact of sea level rise,typhoon intensity on the storm surge in Qiongzhou Strait and its adjacent waters in the future,at the same time judging the mutual effect of global warming and reclamation,hoping to provide basis for disaster prevention and mitigation of the storm surge in the study area.In this paper,a coupled numerical model of tide and storm surge was established in study area,based on the strong typhoon“haiou”,studying the effect of sea level rise,typhoon intensity and their mutual effect on the storm surge under different typhoon paths in the future.The main work and conclusions are as follows:1.The maximum storm elevation variation caused by sea level rise 0.5m and 1.0m were simulated,comparing to the present condition.The results show that a larger sea level rise will lead to a greater change in the storm surge.Different paths of typhoons in the same sea area will cause different changes in maximum storm elevation,and in overall the biggest increase was within 5%.2.The maximum storm elevation variation in the shallow water area of the nearshore were analyzed by simulating the typhoons of different paths and enhancement typhoon intensity of 5% and 10%.The results show that the maximum storm elevation will increase with the intensity of typhoon,the stronger the typhoon is,the larger the increasment is.And the closer the typhoon is to the study area,the greater the impact of intensification on the maximum storm surge is.When the intensity of typhoons in each path is increased by 5% and 10%,the increase water growth rate of the near shore of the study area is up to 14% and 25%.The intensity of typhoons in each path not only increases the maximum storm surge but also increases the time of maintaining high water level near the shorelines.3.With the combined effects of sea level rise and intensification of different path typhoons,the change of the maximum storm surge in shallow water area near shore were simulated and analyzed.The results show that the maximum change is 25.66%,which is slightly less than the linear addition of sea level rise and typhoon intensity,26.51%.By the end of 2100,considering the change of storm surge caused by climate warming,the maximum storm surge in the west part of north bank in the Qiongzhou Strait will increase by 26%,the maximum storm surge in the west part of south bank and the east part of north bank will increase by 18%,the maximum storm surge in Leizhou bay will increase by 15%,and the other part of the Leizhou Bay will increase by 8%.It is suggested that the height of bank should be raised.4.The impact of climate change and reclamation on the maximum storm surge in haikou bay were simulated and analyzed.The results show that by the end of 2100,maximum storm surge along the haikou bay with the plan of 1200 meter from the bay will increased by 19%,while with the plan of 200 meter from the bay will increased by 28%.A reasonable reclamation will reduce the storm surge.