Use of GPS in Landslide Monitoring in Bududa District.
Abstract
Landslides are one of prominent geo-hazards that frequently affects Bududa District in Uganda, especially in the rainy season. It destroys not only environment and property, but usually also causes deaths. Landslide monitoring is therefore very crucial and should be continuously done. One of the methods that can have a contribution in studying landslide phenomena is repeated GPS survey method. This research work presents and discusses the operational performances, constraints and results of GPS surveys conducted in well-known landslide prone areas in Bududa. Five GPS surveys involving 11 GPS points have been conducted, namely on June 2018, September 2018, November 2018, February 2019 and April 2019, respectively. The estimated landslide displacements in the area are relatively quite large in the level of a few cm. Displacements vary both spatially and temporally. This study also suggested that in order to conclude the existence of real and significant displacements of GPS points, the GPS estimated displacements should be subjected to a type of test called the congruency test on spatial displacements. The observed stations failed the congruency test at epoch level while some showed to be stable over the observation period tending towards a year. The research asserted movement of Bududa District and advised for installation of CORS stations for a more comprehensive modelling of the deformation in Bududa District.