Ground surface deformation monitoring using Interferometric synthetic aperture radar. (case study Rwenzori sub region, Kasese district)

Abstract

Due to the recent occurrence of landslides and ground movements in Kasese district. It is one of the areas at a risk of experiencing ground deformation. This report presents the findings of a comprehensive study conducted to investigate the spatial surface deformation in Kasese district from 2015 to 2022. The objective of the study was to analyze and understand the causes and patterns of ground deformation in the region using Differential Interferometric Synthetic Aperture Radar (InSAR) technique. The study area, located in the East African Rift system, is characterized by high tectonic activity and is prone to landslides, earthquakes, and volcanic eruptions. The research utilized Sentinel-1 SAR data for the period from 2015 to 2022 to generate interferograms and extract deformation information. The data analysis included steps such as image registration, debursting, topographic phase removal, Goldstein phase filtering, and phase unwrapping. The resulting displacement maps provided insights into the magnitude and direction of ground deformation. The findings revealed notable variations in deformation patterns across the years. In 2015, the region experienced significant subsidence, with an average deformation of -0.5729 meters. Subsequent years showed varying trends, including uplift and subsidence. Factors such as volcanic activity, tectonic movement, and hydrological changes were identified as potential causes for the observed deformation. The comparison between field observations and INSAR results indicated a high level of agreement, validating the accuracy and reliability of the obtained deformation information. The study highlights the significance of INSAR as a valuable tool for monitoring and understanding ground deformation in mountainous regions. It provides crucial information to stakeholders, including government agencies and local communities, to make informed decisions regarding land use planning, infrastructure development, and disaster mitigation strategies.