Budhigandaki Flood: How Did the Bhotekoshi Events Help Avert Major Damage?
Preliminary studies by the Water Resources and Hydrology Research Center indicate that the flood in Gorakh’s Budhigandaki River was caused by a landslide similar to the devastating Bhotekoshi-Trishuli flood on September 10. Senior hydrology expert Vinod Parajuli of the center stated that additional satellite imagery is being analyzed to prepare a detailed report on the causes of the landslide and flood. “It appears a large area of permafrost (frozen ground) collapsed from an altitude of approximately 5,000 meters. As it descended, it triggered further landslides,” Parajuli explained. “Therefore, the Budhigandaki flood bears many similarities to the Rasuwa-Bhotekoshi flood.”
Given this similarity, how was a large-scale human and material loss like that seen in the Bhotekoshi-Trishuli flood avoided in the Budhigandaki event? Experts have highlighted several possibilities. While over 1,400 deaths have been confirmed and more than 5,000 remain missing due to the Bhotekoshi-Trishuli flood, authorities reported only five people uncontactable following the Budhigandaki flood.
Experts have noted that the speed of the Budhigandaki flood was significantly lower compared to the Bhotekoshi-Trishuli event. Vasant Raj Parajuli, Executive Director of the Disaster Studies Center at the Engineering Institute Pulchowk, explained that landslides temporarily dammed the river in Budhigandaki, reducing the flood’s velocity and thereby mitigating damage to some extent. “Since the flood contained more sediment than water, it flowed more slowly, which limited its destructive impact on the lower Budhigandaki areas,” he said.
Additionally, experts pointed out that the quantity of sediment like silt, stones, sand, and rock particles accompanying the flood was less in Budhigandaki compared to Bhotekoshi. Hydrology expert Parajuli also noted the presence of abundant black soil in the Budhigandaki flood area. Earlier studies estimated the average speed of the Bhotekoshi-Trishuli flood at around 100 kilometers per hour. Preliminary findings indicate that the Budhigandaki flood moved at a speed between 40 to 50 kilometers per hour. However, as the exact initiation time of the flood remains uncertain, the research center continues efforts to determine its actual speed accurately.