Nepal's steep topography significantly contributes to the severity and rapid onset of its catastrophic flooding events, according to hydrologists. The country's dramatic elevation changes mean that floodwaters can travel downhill with immense speed, leaving victims with very little time to react and evacuate.
Raha Hakimdavar, a hydrologist and visiting professor at Georgetown University in Qatar, highlighted how this geographical characteristic intensifies the danger. The rapid descent of water down Nepal's mountainous terrain accelerates the flow, making it difficult for communities to prepare for or escape the inundating waters. This phenomenon is a critical factor in the high impact of flooding in the region, where swift-moving water can cause widespread destruction in a short period.
The unique geological makeup of Nepal, characterized by the Himalayas, creates a natural landscape prone to flash floods and landslides, especially during monsoon seasons. The steep slopes channel rainfall directly into river systems, causing them to swell rapidly and overflow their banks. This creates a dynamic where natural processes are amplified, leading to devastating consequences for those living in the valleys and downstream areas.