Typhoons And Storm Tides Risks In Guangdong

By Dr. Xiaohong Chen, Huiwen Bai 20 October, 2020

Already vulnerable Guangdong has to now deal with increasingly unpredictable storm tides. SYSU's Chen & Bai expand

Located on the west coast of the Pacific Ocean, Guangdong Province borders the South China Sea with a  4,300km coastline that accounts for about one-fifth of the total coastline of China. It is also one of the main areas where typhoons land frequently, mostly in summer and autumn. The Pearl River Delta and the coastal areas of east and west Guangdong Province has suffered from mammoth annual disaster losses caused by tropical storms as they are more densely populated and economically developed.

34.5% of typhoons landing on China are in Guangdong…

…= RMB15bn annual economic loss

Typhoons can also induce secondary disasters such as heavy rains, floods, collapses of infrastructure, landslides, mudslides, soil erosion, etc., thereby multiplying the damage caused by typhoons. According to statistics, typhoons that landed and/or severely impacted Guangdong amount to 5.3 per year. Of which 3.7 of them landed in Guangdong Province, accounting for 34.5% of typhoons that landed on China. The average annual economic losses caused by typhoons in Guangdong in the past decade was RMB15.13 billion.

Damages from past significant typhoons

1. Severe Typhoon Hagupit (No. 14) – In 2008 landed in Maoming City, Guangdong on September 24 with a wind force of 15 and the lowest central air pressure of 940hPa. It affected 7.37 million people and cost 22 lives. It also affected 409,750 hectares of agricultural lands and destroyed 29,211 houses. The direct economic losses amounted to RMB11.4 billion.
2. Super Typhoon Rammasun (No. 9) – In 2014 landed in Xuwen, Guangdong on July 18 with a wind force of over 17 and the lowest central air pressure of 899hPa. It caused 62 deaths and 18 injuries in China, plus affecting ~2.5 million people spanning across 205 villages in 22 cities. It also affected 201,009 hectares of agricultural lands and destroyed 11,045 houses. The direct economic losses amounted to RMB13.1 billion.
3. Typhoon Mujigae (No. 22) – In 2015 landed in Zhanjiang, Guangdong on October 4 with a wind force of 15 and the lowest central air pressure of 975hPa. It caused 18 deaths and 223 injuries in Zhanjiang and affected 4.98 million people in the province. It also impacted 330,100 hectares of agricultural lands and destroyed 8,324 houses. The direct economic losses amounted over RMB23.2 billion.
4. Typhoon Hato (No. 13) – In 2017 landed in Zhuhai, Guangdong on August 23 with a wind force of 14 and the lowest central air pressure of 950hPa. It caused 16 deaths, affected 50,467 hectares of agricultural lands, destroyed 6,425 houses, and led to power and water outages in most areas. The direct economic losses amounted to RMB11.85 billion.
5. Super Typhoon Mangkhut (No.22) – In 2018 landed on the coast of Jiangmen, Taishan and Haiyan Town, Guangdong on September 16 with a wind force of 14 and the lowest central air pressure of 955hPa. It cost 5 lives and forced the government to evacuate 951,000 people in 14 cities. It also affected 193,333 hectares of agricultural lands and destroyed 1200 houses. The direct economic losses in the agricultural sector amounted to roughly RMB5.2 billion.

Characteristics and patterns of typhoons’ damages

The origin and intensity of a typhoon

Typhoons affecting Guangdong originate either from the Pacific Ocean or South China Sea – the Northwest Pacific Ocean generates 28 typhoon per year while the South China Sea generates less (on average 5 per year) and weaker typhoons.

64% of typhoons affecting Guangdong are from the Pacific Ocean

64% of typhoons affecting Guangdong are from the Pacific Ocean (most of which are typhoons and tropical storms) and their landing time are mainly in July. Another 36% of typhoons are from the South China Sea (most of which are tropical storms and tropical depression) and their landing time are mainly in August. However, in recent the two years, the number of typhoons landing in Guangdong has decreased sharply with only 3 tropical storms landing this year.

Characteristics of typhoon activity path

The number of landing typhoons from west to east is decreasing. Landing typhoons usually move with certain paths and patterns:

• Land on the western coast of Guangdong and move westward to Guangxi
• Land on the proximity of Peal River Estuary and move to the north
• Land on the eastern coast of Guangdong and move to the north-west or the west
• Land on the eastern coast of Guangdong and move to the north

Changes of disaster characteristics

In recent years, the characteristics of storm tides along the Guangdong Province have changed and become more unpredictable in terms of frequency, magnitude, and landing locations & time. Moreover, climate change and human activities such as rapid socio-economic development of coastal areas have increased the vulnerability of coastal areas to storm tides.

Vulnerability of disaster-bearing regions

Several regions in Guangdong Province are highly vulnerable to storm tides and coastal threats as they have higher population density, GDP, roads network density, and land utilisation rate.

Many regions in Guangdong are highly vulnerable to storm tides & coastal threats

They are Zhuhai, Zhongshan, Dongguan, Shenzhen, Zhanjiang, central and eastern Foshan, southwestern Guangzhou, southern Maoming, southern Yangjiang, central and southern Jiangmen, southern Shanwei and southern Shantou.

More typhoon-related research needed in the future

The coastal area of ​​Guangdong is one of the regions where typhoons landed the most and inflicted the most local damages in China. These damages are escalating due to increasing population density and economic development.

With escalating damage, it is paramount to strengthen research

Therefore, it is paramount to strengthen research on typhoons forecasting and early-warning and pay special attention to storm tides’ new characteristics, their causes as well as potential impacts. More attention should also be paid on raising awareness towards risks and disaster mitigation and compliment them by strengthening research on disaster prevention and management.

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• China Can Water Down Impact Of Floods – China has long suffered from floods; 7/10 worst floods were in China. Global water gurus Asit Biswas & Cecilia Tortajada look at the great advancements China has made to mitigate flood impacts
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