Detection of Land Subsidence in Kathmandu Valley, Nepal, Using DInSAR Technique

A study applying Differential Synthetic Aperture Radar Interferometry (DInSAR) to ALOS PALSAR data detected significant land subsidence in Kathmandu Valley, Nepal, between 2007 and 2010. Subsidence areas, ranging from 1 km² to 9.9 km², exhibited velocities of up to 4.8 cm/year, with depths reaching 17 cm. The phenomenon was predominantly observed in old settlement zones with mixed land use, correlating with high concentrations of groundwater extraction wells. Geological formations, primarily unconsolidated fine-grained sediments, were identified as the primary factor contributing to subsidence due to groundwater extraction. This research highlights the vulnerability of urban areas built on such geological substrates to subsidence risks.

Bhattarai, R., Alifu, H., Maitiniyazi, A., & Kondoh, A. (2017). Detection of Land Subsidence in Kathmandu Valley, Nepal, Using DInSAR Technique. Land, 6(2), 39. https://doi.org/10.3390/land6020039