When the 'Guardian Mountain Range' Becomes a Double-Edged Sword: Taiwan's Geographic Fate with Typhoons

30-second overview: Taiwan is hit by an average of 3.5 typhoons per year. These tropical cyclones contribute nearly 50% of the island's total rainfall, yet they are also the source of the most extreme compound disasters. People commonly call the Central Mountain Range the "Guardian Mountain Range," but meteorology experts warn that this concept of a barrier protecting the west ignores the devastating destruction wrought by orographic rainfall. From Japanese colonial-era meteorological observation to modern high-tech early warning systems, this article explores this long-running struggle with nature from both scientific and human perspectives.

"This disaster let me live my life over again — I don't know whether that's fortunate or not." On August 8, 2009, Typhoon Morakot devastated Xiaolin Village in Kaohsiung. Fifty-six-year-old Weng Jui-Chi had gone up the mountain early that morning to check a worksite and survived by luck — only to witness in an instant as a mudslide swallowed the entire village, losing 11 family members including his wife and children.¹

Weng Jui-Chi's story is the most painful emblem of Taiwan's confrontations with typhoons. Taiwan sits at the strategic intersection of Western Pacific typhoon paths, and the island's history has been substantially carved by these rotating low-pressure systems. Every year, an average of 3 to 4 typhoons strike Taiwan; while bringing abundant water resources, they come paired with compound disasters of strong winds, torrential rain, and storm surge, leaving deep impacts on Taiwan's landscape and social structure.²

The Historical Beginning: From Qing Dynasty Flags to Japan's Observation Network

Taiwan's typhoon observation history can be traced back to the Tongzhi era of the Qing dynasty, when the British hung colored wind-and-rain flags on the roof of Takow (today's Kaohsiung) Mu Te Hospital as the earliest storm warning system.³ In the Japanese colonial period, Japan expanded meteorological observation into a "climate observation network," establishing the "Civil Administration Bureau Observatory of the Taiwan Governor-General's Office" in Taipei in 1896 and progressively setting up storm warning signal stations at ports including Anping, Takow, Touwei, and Su'ao. By 1902 all 15 port government offices across Taiwan had meteorological observation facilities, laying the foundation for modern weather forecasting.⁴ These early efforts were not only for maritime route safety and ocean trade — they also provided invaluable data for subsequent typhoon disaster relief.

The Scientific Truth About the Guardian Mountain Range: Shield or Amplifier?

Whenever a typhoon approaches from east to west, Taiwanese instinctively look toward the Central Mountain Range with its average height exceeding 3,000 meters. The public affectionately calls it the "Guardian Mountain Range," grateful that it disrupts typhoon structures and protects the western half from direct strong winds. However, in meteorologists' eyes this title carries strong "parochialism."

📝 Curator's note
"Guardian Mountain Range" is a placebo. It really does weaken the wind — but it squeezes out the water. For mountain areas on the windward side, this range is not a god but an amplifier of disaster.

Former Central Weather Bureau Forecast Center director Wu Te-Jung has publicly refuted the Guardian Mountain Range narrative on multiple occasions. He noted that if Taiwan were flat, Typhoon Morakot's rainfall would be "worlds different." It is precisely because of the towering terrain forcing warm moist air upward that extreme rainfall falls on the windward side.⁵ This orographic effect causes mountainous areas to receive extreme rainfall far exceeding the plains, triggering serious flooding and mudslides. Meanwhile, when the typhoon circulation descends over the mountain range on the leeward side, it commonly causes a hot, dry foehn wind on the lee side (such as in Taitung and Taichung regions), causing serious damage to crops.⁶

Compound Disasters and Economic Impact: When Storm Surge Meets Land Subsidence

A typhoon's threat is never singular. In the southwestern coastal areas of Yunlin, Chiayi, and Pingtung, the low pressure of a typhoon causes storm surge — an abnormal rise in sea level. When this water surges toward areas with long-term land subsidence from excessive groundwater extraction, seawater intrusion becomes an unavoidable nightmare.⁷

More threatening is the "secondary damage" after a typhoon leaves. When the typhoon center moves to the Taiwan Strait, its circulation commonly draws in strong southwesterly airflow. This warm moist air from the South China Sea, forced upward by topography, frequently produces rainfall in the southern mountains that exceeds even what fell during the typhoon itself. Typhoon Morakot in 2009 is the classic case — the extreme rainfall it triggered resulted in 462 deaths in Xiaolin Village.¹

The economic impact of typhoons on Taiwan should not be underestimated. Taking agriculture as an example: in 2025, the combined effects of Typhoon Danas and heavy rainfall caused agricultural losses of NT$2.07 billion, with bananas and pomelos suffering the most severe damage.⁸ Even high-tech industries are not immune — while the 2024 Typhoon Gaemi saw no disaster reports from major science parks, the strong rainfall it brought still put pressure on surrounding infrastructure, highlighting the importance of industrial resilience under extreme climate.⁹

The Social-Cultural Phenomenon: Typhoon Holidays and the Dilemma of Decisions

In Taiwan, typhoons are not only natural disasters — they have also generated a distinctive "typhoon holiday" culture. When a typhoon strikes, county and city chiefs face enormous decision-making pressure: calling a holiday could cause hundreds of billions of NT dollars in economic losses (some experts estimate a single typhoon holiday costs NT$31.5 billion),¹⁰ while not calling one could trigger public anger and safety concerns. This phenomenon of "same holiday, different situations" reflects the tension in Taiwanese society between protecting lives and economic development. Typhoon holidays have evolved from their original purpose of protecting public safety into a complex social phenomenon and even a test of county and city chiefs' popular support.¹¹

The Technology Frontier: From Formosat-7 to Precision Forecasting by Drone

Facing increasingly complex typhoon patterns, Taiwan's investment in meteorological technology has continued to advance. Formosat-7 (Formosat-7) improves typhoon track and intensity forecast accuracy by receiving GNSS (Global Navigation Satellite System) signals and providing approximately 4,000 sets of atmospheric data daily.¹² Additionally, drone technology applications have brought new breakthroughs in typhoon observation — capable of penetrating into typhoon eyes to obtain first-hand data, compensating for the limitations of traditional observation. These technological advances have made Taiwan more resilient in typhoon early warning and disaster response.

Historical Scars: Learning Resilience from Disasters

Taiwan's disaster prevention system has been built upon lessons learned through repeated tragedy:

1. 1996 Typhoon Herb — Triggered large-scale mudslides, leading to the establishment of a mudslide early warning system.⁶
2. 2001 Typhoon Nari — Severe flooding in the Taipei metropolitan area, MRT system paralyzed; strengthened urban flood control and underground facility waterproofing standards.²
3. 2009 Typhoon Morakot — Extreme rainfall in southern and central Taiwan triggered the "8/8 Disaster," prompting a comprehensive review of land planning and disaster prevention systems.¹
4. 2024 Typhoon Gaemi — Strong circulation combined with southwesterly airflow caused flooding in multiple southern locations, again challenging cities' flood absorption resilience under extreme climate.⁹

✦ "If it weren't for the Central Mountain Range, Typhoon Herb wouldn't have dumped 2,000 millimeters of rain on Alishan." (Paraphrase of meteorological expert Wu Te-Jung)⁵

Conclusion: Coexisting with Uncertainty

Against the backdrop of climate change, typhoons are becoming stronger, their tracks more erratic, and their rainfall more extreme. Taiwanese society is shifting from the early "passive disaster avoidance" toward "active adaptation."

In 2019, on the tenth anniversary of Typhoon Morakot, Weng Jui-Chi reorganized his family with neighbor Yang Mei-Lu, who also lost family members, in the permanent housing at Wulipu. He said: "Life has to go on."¹ This sentence perhaps also represents the spirit of this island: through the baptism of wind and rain, continually seeking paths toward rebirth and sustainable coexistence.

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