Flood Disasters and Impacts in Yuanlin City Before the Construction of Detention Basins

 

In recent years, global climate change has become increasingly serious, and extreme weather events have occurred more frequently. Taiwan is located in a subtropical region and is often affected by the plum rain season, southwestern monsoon flows, and typhoons during the summer. These weather systems can bring heavy rainfall within a short period of time. When rainfall is too intense, urban drainage systems may not be able to handle the large volume of water, resulting in urban flooding. In the past, Yuanlin City in Changhua County experienced frequent flooding due to geographical conditions, drainage limitations, and extreme rainfall events.

 

From a geographical perspective, Yuanlin City is located on the Changhua Plain, where the terrain is relatively flat. Because the land slope is gentle, rainwater flows slowly and can easily accumulate in low-lying areas. In addition, several drainage systems run through and around the city, such as Guogou Drainage and Donggou Drainage. When heavy rain occurs in a short period of time, these drainage systems may exceed their capacity, causing water to accumulate and flood nearby areas. Furthermore, rapid urban development has increased the number of roads, buildings, and paved surfaces. These impermeable surfaces reduce the amount of land that can naturally absorb rainwater, increasing surface runoff and making flooding more likely.

 

Under the influence of climate change, extreme rainfall events have become more frequent and intense. When strong convective storms or typhoons bring large amounts of rain within a short time, urban drainage systems often cannot discharge the water quickly enough. For example, during one heavy rainfall event in Yuanlin, the accumulated rainfall reached 119 millimeters within three hours, with a peak hourly rainfall of 76 millimeters. This far exceeded the design capacity of the local stormwater drainage system, causing serious flooding in several parts of the city.

 

Before detention basins were constructed, many areas in Yuanlin City were prone to flooding during heavy rainstorms. Roads such as Juguang Road and areas near Yuanlin Christian Hospital were known to experience frequent water accumulation. Some low-lying areas recorded flood depths of up to 50 centimeters during severe rainfall events. These floods not only disrupted transportation but also threatened the safety and daily lives of local residents.

 

Flooding can have many negative impacts on a city. One major impact is on transportation. When roads are flooded, vehicles may not be able to pass safely, and traffic congestion can occur. Another impact is on daily life and local businesses. When homes or shops are flooded, furniture, equipment, and goods may be damaged, causing economic losses for residents and shop owners. In addition, flooding can create public safety risks, especially for pedestrians and motorcyclists traveling through flooded streets. Long periods of standing water may also lead to environmental sanitation problems, such as mosquito breeding and water pollution.

 

Beyond these direct impacts, urban flooding also highlights the vulnerability of cities facing climate change. As extreme rainfall becomes more common, traditional drainage systems alone are often insufficient to handle sudden surges of rainwater. Therefore, new flood control strategies are needed, such as detention basins, stormwater storage facilities, and green infrastructure systems. These solutions can temporarily store rainwater during heavy storms and gradually release it afterward, reducing pressure on urban drainage systems.

 

Because of the long-term flooding problems and the increasing threat of extreme rainfall, the government began planning and constructing detention basin projects in Yuanlin. These facilities were designed to temporarily store excess rainwater during storms, reduce the burden on drainage systems, and lower the risk of urban flooding. The construction of such flood control infrastructure represents an important step toward improving urban resilience and sustainable environmental planning in response to climate change.

 

Overall, before detention basins were built, Yuanlin City frequently faced flooding problems due to its flat terrain, rapid urbanization, and increasing extreme rainfall caused by climate change. These challenges highlighted the urgent need for improved flood control measures and played a key role in promoting the development of detention basin projects in the city.

References

 

1.Central News Agency

https://www.cna.com.tw/news/afe/201807020308.aspx

 

2.People Media Report

https://www.peoplemedia.tw/news/874e93fe-b482-4732-9a5f-e2eb5799cdba

 

3.United Daily News Video Report

https://video.udn.com/news/1239370