Core Points - The National Marine Forecast Center has upgraded the wave warning to orange and issued a storm surge yellow warning due to the combined effects of strong cold air and Typhoon "Fengshen" [1][2] - Significant wave heights of 3 to 5.5 meters are expected in the East China Sea, Taiwan Strait, and northern South China Sea from the afternoon of October 19 to the afternoon of October 20 [1] - Coastal areas in Fujian will experience waves of 3 to 4.5 meters, while Shanghai, Zhejiang, and eastern Guangdong will see waves of 2.5 to 3.5 meters [1] - Storm surge levels of 50 to 120 centimeters are anticipated along the coast from Nantong, Jiangsu to Zhangzhou, Fujian, and 30 to 70 centimeters from Chaozhou to Huizhou, Guangdong [2] - Yellow and blue storm surge warning levels have been issued for various cities in Zhejiang and Fujian provinces, as well as parts of Guangdong [2] Group 1 - The wave warning has been upgraded to orange, indicating severe conditions in specific coastal areas [1] - The expected wave heights pose significant risks for maritime operations, necessitating safety precautions [1] - The storm surge warnings highlight the potential for flooding and require emergency preparedness from local governments [2] Group 2 - The forecasted storm surge levels indicate a serious threat to coastal infrastructure and necessitate protective measures [2] - Local authorities are advised to organize vessels to return to port and reinforce aquaculture facilities [2] - Continuous monitoring and reinforcement of coastal defenses are essential to mitigate risks from the storm surge [2]

Core Viewpoint - The National Marine Forecast Center has issued a blue alert for storm surges due to strong cold air, predicting significant water level increases in specific coastal areas on October 8 [1] Group 1: Storm Surge Predictions - The Bohai Bay is expected to experience storm surge increases of 50 to 140 centimeters [1] - Laizhou Bay is forecasted to see storm surge increases of 40 to 100 centimeters [1] Group 2: Affected Areas and Preparedness - Tianjin, Tangshan in Hebei Province, Cangzhou, and Binzhou in Shandong Province are under a blue alert for storm surges [1] - Coastal units are advised to prepare for emergency responses to the storm surge [1] - Relevant marine production units are instructed to organize fishing boats, aquaculture rafts, and farms to strengthen defenses and prepare for potential flooding [1]

Core Points - Storm surge is a major marine disaster affecting China, causing 99% of direct economic losses from various marine disasters in recent years [1] - The National Marine Forecasting Center has raised the storm surge warning level to the highest red level due to Typhoon "Maidum" [1] Group 1: Storm Surge Overview - Storm surge is caused by tropical cyclones, temperate cyclones, and other storm systems, leading to abnormal sea level rise or fall [2] - The disaster can result in ship collisions, grounding, or sinking, and damage to coastal aquaculture and salt production [3] Group 2: Warning Levels and Recommendations - Storm surge warning levels are categorized into four: blue, yellow, orange, and red [5] - During the red warning period, it is advised to evacuate nearshore personnel, close dangerous coastal areas, and inspect coastal defenses [7] Group 3: Impact of Combined Storm Surge and Astronomical Tide - The current period coincides with astronomical tides along the coasts of Guangdong and Hainan, potentially leading to over three meters of storm surge [8] - If a storm surge coincides with a high astronomical tide and strong winds, it can lead to significantly higher tide levels and more severe impacts [11]

Core Viewpoint - The article discusses the severe impact of Typhoon "Haikashan" on coastal areas such as Zhuhai, Hong Kong, and Macau, leading to significant seawater inundation due to storm surges combined with astronomical tides [1][3][4]. Group 1: Causes of Seawater Inundation - Seawater inundation occurs when seawater enters land through surface or underground pathways, often exacerbated by geological structures, tides, and typhoons [1]. - The phenomenon is driven by two types of tides: astronomical tides caused by lunar and solar gravitational forces, and storm surges resulting from strong winds and low atmospheric pressure during typhoons [1][5]. - During the impact of Typhoon "Haikashan," the coastal areas were experiencing astronomical high tides, which contributed to the abnormal rise in water levels [3]. Group 2: Impact of Typhoon "Haikashan" - The maximum storm surge recorded in Guangdong's coastal areas reached 278 centimeters, with the most affected region being the Pearl River Estuary [3]. - In Zhuhai, the storm surge combined with astronomical high tide resulted in a peak water level of 328 centimeters, exceeding the red alert level by 43 centimeters [3]. - The coastal areas experienced significant wave heights, with effective wave heights recorded at 6.5 meters, leading to damage to coastal defenses and further exacerbating seawater inundation [3]. Group 3: Historical Context - Similar seawater inundation events occurred in Guangdong last November due to Typhoon "Wangyi," which, despite being weaker, still caused tidal levels to exceed warning thresholds when combined with astronomical tides [5]. - It is noted that typhoons are not the sole cause of seawater inundation; astronomical tides also play a critical role in these events [5]. Group 4: Prevention and Mitigation Strategies - Effective storm surge warnings are crucial for coastal areas to prepare and mitigate the impacts of seawater inundation [6]. - Recommendations include preemptive measures such as installing flood barriers, sealing underground drainage systems, and preparing emergency response plans [6]. - In areas already affected by seawater inundation, immediate evacuation and drainage efforts are essential to minimize damage [6].

Core Points - The article discusses the impact of Typhoon "Haikashan" on coastal areas in Guangdong Province, particularly the risk of seawater backflow in low-lying regions [1][2] - The typhoon is expected to make landfall between Taishan and Zhanjiang in Guangdong on the afternoon to evening of September 24, with maximum wind speeds of 55 m/s (approximately 198 km/h) [1] - A red alert for storm surges has been issued for several cities in Guangdong, indicating a significant risk of flooding [2] Group 1 - Coastal low-lying areas in Shenzhen, Dongguan, Guangzhou, Zhongshan, and Zhuhai are at high risk of seawater backflow due to Typhoon "Haikashan" [1][2] - The storm surge is expected to reach 60 to 120 cm in certain areas, with the highest levels of 120 to 280 cm forecasted for the coastline from Huizhou to Yangjiang [2] - Emergency response measures are in place, including the evacuation of residents in vulnerable areas and the closure of coastal recreational facilities [2] Group 2 - Citizens are advised to monitor storm surge warnings and prepare for potential urban flooding, including avoiding contact with metal objects during storms [3] - Recommendations for navigating urban flooding include using sturdy objects to probe for deep water and avoiding low-lying areas [3] - Precautionary measures for homes in low-lying areas include creating barriers to prevent water ingress and using waterproof materials for storage [3]

Group 1 - Typhoon "Hagupit" is expected to be the strongest typhoon to make landfall in China this year, with significant impacts anticipated [1] - The typhoon has a diameter exceeding 1000 kilometers, indicating its large energy and abundant moisture, necessitating high attention to its subsequent effects [1] - The cold air moving southward is influencing the typhoon's path, which will primarily move westward along the coasts of Guangdong and Guangxi [1] Group 2 - The typhoon's wind radius is 150 kilometers, and vessels in the affected sea areas are advised to return to port and secure port facilities [1] - The combination of the astronomical tide during the lunar calendar's third day and the storm surge from "Hagupit" may lead to seawater backflow in the Pearl River Estuary [2] - Residents are urged to prepare emergency supplies, secure windows and doors, avoid going outside, and closely monitor relevant warnings and forecasts [2]

Core Viewpoint - The super typhoon "Haikui" is the strongest typhoon affecting China this year, with significant impacts expected on coastal areas, particularly in Guangdong and Fujian provinces [1][2]. Group 1: Typhoon Characteristics - Typhoon "Haikui" has reached a strength of 17 on the scale, making it the "global wind king" of the year [1]. - The typhoon is expected to move at a speed of approximately 20 kilometers per hour and will weaken slightly after crossing the Bashi Channel [2]. Group 2: Storm Surge and Tidal Effects - There is a high likelihood of seawater backflow in the Pearl River Estuary and nearby coastal areas due to the combination of storm surge and astronomical tides [2][3]. - The storm surge is expected to exceed 300 centimeters in the Pearl River Estuary, coinciding with high astronomical tides on September 23 and 24 [2][3]. Group 3: Wave Conditions - The coastal waters of Guangdong and Fujian are forecasted to experience large to giant waves, with wave heights reaching up to 13 meters near the typhoon's center [4][5]. - The National Marine Forecast Center has issued warnings for wave heights of 8 to 13 meters in the Bashi Channel and northeastern South China Sea [5]. Group 4: Emergency Preparedness - Various cities in Guangdong have announced measures such as school closures and halting public transport in anticipation of the typhoon's impact [6]. - The National Flood Control and Drought Relief Headquarters has initiated a Level 4 emergency response for flood and typhoon prevention in Guangdong, Hainan, and Fujian [6].

Core Points - Typhoon "Zhu Jie Cao" made landfall in Shanghai on July 30, 2023, as a tropical storm with maximum wind speeds of 9 levels (23 m/s) and a minimum central pressure of 978 hPa [1] - Significant wave heights of 3 to 4.5 meters were reported in the coastal waters of Shanghai and northern Zhejiang, with storm surges of 70 to 150 cm observed from Nantong, Jiangsu to Ningbo, Zhejiang [1] Wave Alerts - The National Marine Forecast Center issued an orange wave alert due to Typhoon "Zhu Jie Cao," predicting wave heights of 3 to 5.5 meters in the southern Yellow Sea and northern East China Sea from the night of July 30 to the daytime of July 31 [3] - Coastal waters near Shanghai are expected to experience wave heights of 3 to 5 meters, while southern Jiangsu and northern Zhejiang will see waves of 3 to 4.4 meters, with respective alert levels of orange and yellow [3] Storm Surge Alerts - A blue storm surge alert was issued, forecasting storm surges of 60 to 140 cm along the coast from Lianyungang, Jiangsu to Hangzhou Bay from the evening of July 30 to the daytime of July 31 [5] - Authorities are advised to prepare for storm surge defenses, including securing fishing vessels and reinforcing aquaculture facilities [5]

Core Points - The Zhejiang Provincial Marine Monitoring and Forecasting Center issued a yellow alert for storm surge due to Typhoon No. 8 "Zhu Jie Cao" (tropical storm level) [1] - The storm surge is expected to cause water levels to rise by 60 to 120 centimeters along the coast of Jiaxing, and by 50 to 100 centimeters along the coasts of Zhoushan and Ningbo [1] - The storm surge warning level for Jiaxing, Zhoushan, and Ningbo is categorized as yellow, with the possibility of lifting the alert on July 31 depending on the situation [1]