Rapid urbanisation and climate change: key drivers of dramatic flood impacts in Nepal

The study finds that human-induced climate change has increased the intensity of heavy 3-day rainfall events in Nepal by approximately 10% and their likelihood by about 70% compared to a 1.3°C cooler climate. These climate drivers combined with rapid urbanisation in the Kathmandu Valley—which saw a 386% increase in built-up areas between 1990 and 2020—and a 28% reduction in forest cover from 1989 to 2019, significantly increased flood exposure and disrupted natural drainage. The analysis notes that the 2015 Gorhka earthquake and the COVID-19 pandemic acted as compounding factors that increased vulnerability. While the Department of Hydrology and Meteorology provided forecasts, the Kathmandu Valley has historically not been the focus of flood risk management, which typically prioritises the Terai region.

• Rapid urban growth and deforestation in the Kathmandu Valley have severely impaired natural water management and increased human exposure to floods. Built-up areas increased by 386% from 1990 to 2020, and forest cover decreased by 28% between 1989 and 2019.
• Climate models indicate that human-induced climate change has increased the intensity of heavy 3-day rainfall events by 10% and the likelihood by approximately 70% relative to a climate that was 1.3°C cooler.
• Future warming of 2°C above pre-industrial levels is predicted to further increase the intensity of 3-day rainfall events by approximately 3%, though this is considered a conservative estimate.
• The vulnerability of the region was exacerbated by long-term compounding factors, including the 2015 Gorhka earthquake, which weakened infrastructure and destabilised hillsides, and the COVID-19 pandemic, which impacted incomes for the middle and low classes.
• Flood risk management in Nepal has historically prioritised the Terai region, leaving the Kathmandu Valley without a specific focus in risk management efforts despite its high exposure.

APA

World Weather Attribution (2024). Rapid urbanisation and climate change: key drivers of dramatic flood impacts in Nepal. https://www.worldweatherattribution.org/rapid-urbanisation-and-climate-change-key-drivers-of-dramatic-flood-impacts-in-nepal/

Chicago

World Weather Attribution. Rapid urbanisation and climate change: key drivers of dramatic flood impacts in Nepal. 2024. https://www.worldweatherattribution.org/rapid-urbanisation-and-climate-change-key-drivers-of-dramatic-flood-impacts-in-nepal/.

Wikipedia

{{cite report |author=World Weather Attribution |title=Rapid urbanisation and climate change: key drivers of dramatic flood impacts in Nepal |date=16 October 2024 |url=https://www.worldweatherattribution.org/rapid-urbanisation-and-climate-change-key-drivers-of-dramatic-flood-impacts-in-nepal/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldweatherattribution2024rapid, author = {{World Weather Attribution}}, title = {{Rapid urbanisation and climate change: key drivers of dramatic flood impacts in Nepal}}, institution = {World Weather Attribution}, year = {2024}, month = oct, url = {https://www.worldweatherattribution.org/rapid-urbanisation-and-climate-change-key-drivers-of-dramatic-flood-impacts-in-nepal/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }