BANGKOK – A comprehensive study, led by a prominent World Bank economist, has sounded a stark warning on the burgeoning human settlements encroaching into perilous flood-prone regions. The research underscores that China’s rapid urban expansion into vulnerable areas is a significant contributor to this concerning trend.
The findings, authored by Jun Rentschler, highlight an alarming reality where the proliferation of settlements in flood-prone zones has far surpassed the growth in safer locales since 1985. Rentschler states, “At a time when human communities should be adapting to the challenges posed by climate change, many countries are, in fact, accelerating their exposure to the ever-increasing threat of floods.”
The study meticulously analyzed 30 years of satellite imagery, meticulously tracking the global expansion of human settlements while overlaying flood risk maps. Unlike previous studies that often focused on specific regions or flood types, this research cast a wide net, encompassing coastal, rainfall, and river flood risks on a global scale.
The results reveal that by 2015, a staggering 20 percent of all settlement areas found themselves within zones classified as having medium to high flood risks. This marked a substantial increase from the 17.9 percent reported three decades earlier. While the percentage increase might appear modest, it translates into a vast expanse due to the rapid expansion of human habitation worldwide since 1985.
Approximately 76,400 square kilometers of human settlements, equivalent to nearly 48 times the size of Greater London, now confront flood risks exceeding half a meter, according to Rentschler.
The paper, published in the esteemed journal Nature, raises a red flag, cautioning, “These expanding settlements in high-hazard areas solidify flood exposure, guarantee future losses, and necessitate significant investments in flood protection.”
The East Asia and Pacific region emerges as one of the most exposed areas, with China, Vietnam, and Bangladesh at the forefront of urban expansion into flood-prone regions. The authors emphasize, “In Vietnam, where nearly one-third of the coastline has succumbed to urban development, the safest and most productive zones are increasingly occupied. Consequently, new developments are disproportionately compelled into hazardous terrain, including riverbeds and floodplains.”
It’s essential to note that the analysis does not account for potential increases in flood risks attributed to climate change, deforestation, or alterations in riverbeds. Nonetheless, Rentschler underscores that there is little evidence to suggest that flood zones are expanding at a rate commensurate with human settlement growth in these known risk areas, underscoring the urgency for policymakers to address settlement patterns as a pivotal factor.
The study refrains from distinguishing between flood-prone zones in nations with robust protective measures, such as the Netherlands, and those without comparable safeguards. Rentschler acknowledges, “Significant disparities exist in flood protection systems, especially when comparing high- and low-income countries. However, our study scrutinizes relatively rare and intense flood scenarios, scenarios against which even most high-income countries cannot provide full protection.”
Climate change compounds the risk of catastrophic flooding, as a warmer atmosphere holds more moisture, potentially intensifying rainfall events. This transformation means that flood occurrences once deemed to transpire once in a century are now becoming increasingly frequent.
Rentschler argues that comprehending the prevailing settlement trend should serve as the initial step in reshaping urbanization policies in the face of mounting flood threats.
By AFP
