What triggered Nepal's catastrophic 2021 flood -- and could it happen again?

Heavy monsoon rainfall, excessive snowmelt and unstable terrain combined to cause the 2021 Melamchi Valley flood disaster in Nepal, according to new research. The findings highlight how a mix of climate and geological factors intensify disaster risks. The study also shows the value of using high-resolution satellite imagery and digital models of Earth's surface to map landscape changes, create early-warning systems and improve flood preparedness, especially in remote areas.