Note from Lethal Minds:
This is the first of several articles feeding into our upcoming war game and crisis simulation Flashpoint Taiwan. The purpose of this simulation is to simulate a diplomatic crisis in the Taiwan Strait which triggers an invasion of Taiwan by the PLA. This simulation will feature both military practitioners and foreign affairs students and professionals.
As part of this article series, one of our writers Quantico Warfighting Society will be hosting Zoom classes to provide additional context and learning opportunities. The link to these calls will be available on our social media account.
Participants will be assigned to factions in the simulation at random, although preference to leadership positions will be given to those who interact with these articles and with the Zoom classes we will be hosting.
At the end of this article will be a thought exercise. We encourage you to write a brief response to that question and send it in to our email at lethalmindsjournal@gmail.com
Be informed, be prepared, be Lethal.
Dedicated to those who serve, those who have served, and those who paid the final price for their country.
The Sino Taiwanese Conflict Part Two: Terrain and Weather
When discussing a potential invasion of Taiwan by China, the weather and terrain seldom given the attention that is garnered by aspects related to troop composition, equipment disposition, and tactics. While not garnering the same amount of appeal as People’s Liberation Army (PLA) troop or equipment movements in Fujian or surrounding regions; the topic is very important because of how both will play a significant role in shaping the operation. This article will discuss the impact that weather and terrain in shaping a potential Chinese invasion of Taiwan.
Taiwan Strait
The Taiwan Strait is on average, approximately 111 miles wide (180 km) and separates mainland China from the island of Taiwan. The narrowest part of the strait measures approximately 81 miles (130 km) when measured from Pingtandao Island to the northern area of Taiwan. The strait’s depth averages 490 ft (150 m), with a minimum depth measuring at least 82 ft (25 m) located near the middle part of the strait, near the Penghu Islands. The island group is the only land feature found in the strait, along the Median Line. Weather in the strait varies depending on the time of year and season, with the summer monsoon season having the most impact on the strait. During this time, the sea conditions will be range from 5 to 7 on the Beaufort Scale, with waves measuring between 9 to 20 ft (3 to 6 m) high. The wind speed will also range from 17 knots to 33 knots, averaging about 24 knots during the season. While the strait is usually not directly affected by the region’s typhoon season, it will usually affect the weather and sea states at the opening of either end of the strait. The typhoons will also affect the cities located near the strait’s entrances such as the cities of Kaohsiung and Taipei/Keelung. Heavy fog will usually occur throughout the strait during the winter season as well the early spring and late fall.
China
Southeastern China’s Weather
Southeastern China’s climate has a sub-tropical climate with temperatures ranging from the low fifties to the mid-nineties. The region has two long seasons – winter and summer – with two short seasons – autumn and spring – between them. Winter runs from January to March and is typically cold compared to other seasons with highs getting to the mid-sixties. The region experiences a short but intense spring season from April to May, where it sees an increase in precipitation. The region will experience heavy fog usually from February to April and May. The region’s rainy season also coincides with the summer season, which lasts from June to August or September. Humidity and precipitation for the region will gradually increase from the start of summer and peaks around the end of July. Southeastern China will average around 80 inches (2000 mm) of precipitation annually, with the region receiving the most during the rainy season. The region’s typhoon season will also overlap with its rainy season, usually occurring from July to September. Autumn will usually occur from October to December and is largely considered to be the region’s dry season.
Southeastern China’s Terrain
The terrain of southeastern China consists of mountainous terrain with steep valleys found throughout the region. The Wuyishan range dominates the region and acts as a natural barrier between the region and China’s interior and is 6,000 feet (1,800 meters) high. Several other mountains also exist within the region and create a few passes that are high and extremely tough to navigate. However, the region is also home to several rivers such as the Min, Long, and Luoyang Rivers that drain into Quanzhou Bay and other areas along the coast. These rivers created alluvial plains where relatively low sea levels can be found and where cities such Xiamen, Quanzhou, and Ningde were founded. Narrow coastal plains also exist along some of the region’s coastline, with sea level in these areas ranging from 0 to 115 ft (0 to 35 m). The coastal areas have relatively small cities located throughout the region because of the region’s geography and lack of arable land. The region’s coastline measures 2,332 miles (3,752 km) long and is largely uniform in characteristics. The coastline is dominated by submerged rocky shorelines or cliffs that prevent most of the coast from being used for commercial or other purposes. There are also several dozen small islands or islets scattered throughout the coast that also limits the coastline’s use for several purposes as well. However, the alluvial or coastal plains created relatively flat, sandy beaches that are at a lower sea level than the surrounding region. The coastline also has several naturally occurring capes, bays, and other features that could be used to shelter vessels from typhoons or other adverse weather conditions.
Taiwan
Taiwan’s Weather
Taiwan can be described as having two distinct climate types divided by the northern and the southern halves of the island. Northern Taiwan’s climate is described as sub-tropical – like southeastern China – with temperatures ranging from an average high of 95 to an average low of 55 degrees Fahrenheit (35 to 12 degrees Celsius). Seasons will vary depending on the part of the island, with Northern Taiwan experiencing two long seasons – summer and winter – with two short seasons – spring and fall – between them. The summer season usually occurs from June to either the end of August or September and brings increased rainfall. The winter season will usually occur in either November or December and last until April. Heavy fog will usually occur during the winter season as well the early spring and late fall due to the region sharing a similar climate with the Taiwan Strait and southeastern China. The northern part of Taiwan will receive an average of 93.3 inches (2370 mm) of rain per year, which means there are more rainy days than the south. However, precipitation levels are more evenly distributed in the northern region throughout the year. For example, there will be a constant drizzle during most days during the winter season due to the northeastern monsoon winds while the southern region would be in its dry season. Rainfall would also occur during the southern region’s rainy season but to a lesser degree.
Southern Taiwan’s climate is characterized as a tropical monsoon climate with minor temperatures occurring throughout the year. The seasons in the region consist of dry and rainy seasons, with the dry season occur during the winter season or between November and February. During this time, there will be a significant reduction in rainfall compared to the rainy season. The rainy season usually occurs from the late spring to summer or from April to August or September. The precipitation levels throughout the southern part will average approximately 67 inches per year. However, the rain will be mostly concentrated along the southern coast, from the cities of Kaohsiung and Tainan to south of Taichung. The rainy season also means that there would be significantly less rainy days compared to the northern region. The concentrated rainfall is why there are less days with precipitation but more concentrated within the rainy season. The region has strong winds during the monsoon’s rainy season that will on occasion become strong enough to cause damage along the western coast. The monsoon winds will then move either west towards China or north towards Japan and the Korean Peninsula.
The variations in weather patterns found throughout Taiwan measures creates opportunity windows for an invasion to occur. For example, if an invasion were to occur in Taiwan, the PLA would choose either the March to April or September to October timeframes since that would provide the most opportune conditions. Any landing in northern Taiwan would have to consider the constant rainfall and heavy fog that occurs during the winter season, which would hamper any landing or breakout operations. Similar issues will also occur during any beach landing site in southern Taiwan; the PLA would have to pick between March and April or September to October to avoid the rainy season.
Taiwan’s Terrain
Taiwan’s terrain is dominated by mountains that cover approximately 2/3 of the eastern side of the island with rolling plains making up the remaining 1/3 on the western side. The Central Mountain Range dominates this region with the highest peak is the Yushan mountain which is around 13,000 ft (3,952 m) high. There are several smaller mountains and foothills also scattered throughout the range that create steep, narrow valleys. The rolling plains are located within a narrow strip of land that is generally flat with a few exceptions, such as when the area where the plains meet the foothill zone. The foothill zone located in the northern section of Taiwan will extend to most of the region’s coastline. However, there is a strip of alluvial plains located between the cities of Taoyuan and Hsinchu that measures significantly lower than the surrounding area. On average, the plains’ sea level averages between 0 to 32 ft (0 to 10 m) in height depending on the region. The plains located on the island’s southwestern portion have consistently lower sea levels than the northern part with a few exceptions, such as around the city of Taoyuan. The eastern side of the island consists of mainly of foothills and mountains that butt up against the coastline in most places. However, there are some plains – such as the areas surrounding the cities of Zhuangwei, Hualien/Xincheng, and Taitung – located along the eastern coastline. The average sea level for these zones is higher than the sea levels found on the western coastline, with 0 to 91 ft (0 to 28 m) in height.
The island has approximately 974 miles (1,567 km) of coastline that changes significantly depending on location. The island’s northern and eastern coastlines will be made up of rocky coastlines with relatively few beaches. The eastern coastline also has cliffs, most notably the area between the cities of Hualien and Yilan located along the central part of the coast. The cliffs will continue until it reaches the southern tip of the coast, only being broken by a coastal basin located near southeastern city of Taitung. The southern coastline will consist of rocky coastlines located on the island’s southern tip that will give way to relatively flat, sandy beaches interspersed with lagoons, mudflats, and wetlands. The coastline will begin near the cities of Donggan and Kaohsiung and extend northward from the Kaohsiung until the city of Taichung located along the central coastline. There are several coral reefs located off the island’s southern coastline, mostly south of Kaohsiung along the island’s southern tip.
Limitations on PLA’s Planning
Taiwan’s weather and terrain will undoubtedly be an important topic during the discussion during the PLA’s planning for an invasion of Taiwan. The reason why is because both severely limits China’s choices regarding when and where they could potentially land. While the PLA could invade at any time throughout the year, they will likely pick times when it presents the least amount of risk to them as possible. They would likely pick the timeframe of March to April and September to October as the best time to invade given the weather factors. However, the short timeframes available for any invasion means that the PLA would need to quickly prepare an invasion force before the two time periods. Alternatively, the PLA could begin mobilizing the amphibious forces, naval and commercial Roll-On-Roll-Off vessels any invasion requires months before an invasion. The United States and Taiwan would inevitably locate these amphibious loading and staging areas and destroy them to prevent China from massing enough troops to invade. They would also need to change the location of the landing sites, depending on the season, sea states, and rainfall during the leadup to invasion. The terrain surrounding Taiwan’s coasts will also play a key role in shaping the PLA’s invasion plan since the terrain significantly favors Taiwan. There are relatively few sites that China could conduct amphibious landings on due to terrain limiting features such as rocky coastlines, coastal reefs, and mudflats. These features limit the PLA to only 12 to 14 sites viable for an amphibious landing by PLA forces.
Conclusion
Any invasion of Taiwan by China would need to consider how the weather and terrain would affect the beach landings more so than arguably any other factor. The reason why is because of the variety of weather and terrain found not only in Taiwan. The planners would also need to consider the weather and terrain found along China’s southeastern coast and the Taiwan Strait since they would play a significant role in any invasion and amphibious landing. Without considering these factors, any landing would likely fail since it would also be at the mercy of weather such as monsoon winds and heavy fog in addition to defending Taiwanese troops1.
Thought Exercise
A) If you were planning on attacking Taiwan, what terrain or weather condition gives you the greatest concern?
B) If you were planning on defending Taiwan, what terrain or weather condition gives you the greatest concern?