Bangkok: The current massive flooding crisis in Nan province and other northern regions is not unexpected, but rather a predictable disaster. Dr. Thongchai Rojanakanan, an expert in urban planning, water management, and climate change adaptation, and a specialist at the Thailand Environment Institute (TEI), states that it resulted from neglecting academic warning signs and misguided management practices for over four decades. As urban planners and disaster experts, we must acknowledge the reality that the central government's failure to respond is a key factor that has transformed natural risks into recurring tragedies.
According to Thai News Agency, Dr. Thongchai began surveying the Nan province area from 1984-1985 and officially warned between 2000-2002 that the entire province was a "highest-risk area" for both flash floods and landslides. Nan's topography, being a "mountain basin," has physical characteristics that make it susceptible to severe disasters similar to the Nam Kon-Nam Chun event in Phetchabun province-water that comes quickly, forcefully, and with high destructive power. The latest data from GISTDA indicates that Nan has lost over 29,000 rai of forest land. While this figure may seem less than 1% of the total forest area, strategically speaking, the lost land represents "vulnerable points in the high mountains," the last line of defense. When rainfall exceeds 300 millimeters-beyond the ecosystem's capacity to absorb it-combined with flawed urban planning, it leads to irreparable damage.
The real problem isn't just the amount of rainfall, but urban development that "blocks natural water flow" (floodways). Uncontrolled infrastructure expansion has transformed cities into permanent obstacles to water masses, as is evident in key areas. In Chiang Mai, the construction of the 3rd and 4th eastern ring roads is building over low-lying areas that were originally waterways, causing water that would normally drain towards Lamphun to be retained and instead flood the city. Similarly, in Rayong and Pattaya, historical aerial photographs clearly show that canals and ponds were once abundant in the area, but these have now been filled in to build commercial buildings and roads, resulting in "the entire city blocking the waterways."
Human greed is a hindrance to water management, with soaring land values in economic hubs like Bangkok or Rayong making land ownership so strong that people are unwilling to sacrifice even a few centimeters for drainage. There is also encroachment on wetlands, with the issuance of land titles in public wetlands and expansion of structures close to the edges of canals, narrowing the waterways. Furthermore, there is an oversight of the natural dimension, focusing on commercial development without regard for "the right to water."
Dr. Thongchai revealed that one must look for clues before a disaster occurs. He employed a strategy of surveying during the "dry season" to find subterranean anomalies, leading to a startling discovery in 2009-2010. He found that earthquake energy from Sumatra resonated through the Yom River basin in Phichit province, affecting a distance of over 1,000 kilometers. Evidence included the discovery of hot springs with temperatures of 45-50 degrees Celsius rising to the surface of the Yom River near Si Satchanalai, indicating a fault in the earth's crust from which heat energy is leaking. Furthermore, he noted the presence of significant active fault lines such as the Si Sawat Fault and the Chedi Sam Ong Fault.
Aware of the risk of earthquakes measuring 7.0-7.5 on the Richter scale, Dr. Thongchai decided to relocate from Bangkok to Ban Pong District to build an "alternative home" to demonstrate its survival innovation. He used a pyramid-shaped house model, a 10x10x10 meter building, with a 1-meter thick concrete raft foundation designed without piles. This allows the house to move with earthquake waves without collapsing, serving as a prototype of urban restructuring at the household level, ready to cope with the crisis of living in an underground tunnel.
Dr. Thongchai explained that sustainable survival is not about conquering, but about coexisting. Using massive budgets to build concrete walls or giant dams, as in the case of Hat Yai, has proven incapable of withstanding natural forces if the situation is not appropriate for the local context. We must turn to Nature-Based Solutions, as exemplified by successful examples internationally. In Rotterdam, Netherlands, the use of a "strategic trade-off" by sacrificing land along the river to widen the waterway recognizes that water needs space in the city. Similarly, Chengdu in China utilizes the ancient "Dujiangyan" water management system, over 2,000 years old, which uses the principle of "water separation and reduction" instead of damming.
One of the best examples of political will in Thailand is the "Thung Song Model" in Nakhon Si Thammarat province. Dr. Thongchai implemented an urban restructuring strategy that transformed the city's capacity to handle rainfall, increasing its capacity from a previous flood level of 50 millimeters to 200 millimeters, through a 10-year strategic plan. The approach involved strict law enforcement, using judicial processes to sue and demolish all illegal structures encroaching on waterways, and a psychological strategy of employing prisoners as labor in dredging encroached canals to prevent obstruction.
Sacrificing 5% of land to save 95% was communicated until local people accepted the "suffering to end it" approach, agreeing to demolish houses or roads blocking waterways so that the majority of the city would be spared from flooding. The result is that while flooding used to reach waist level for 5-7 days, Thung Song now only has knee-deep water that recedes completely within 1-2 hours, creating long-term stability for the city's residents.
However, recurring floods are not just an engineering challenge, but also an ethical one. The biggest enemy is not the storms themselves, but "human greed" that refuses to allow nature space. A sustainable solution, therefore, requires an "integrated policy" that combines three key pillars: public administration, ecological urban planning, and natural science. Dr. Thongchai concluded, "It's time we stopped using painkillers to alleviate symptoms and embraced a major urban planning overhaul for the stability of Thai society in an era of extreme climate change."