Analysis of topographic parameters underpinning landslide occurrence in Kigezi highlands of southwestern Uganda

Abstract

An assessment of the influence of topography on landslide occurrence in the Kigezi highlands of southwestern Uganda was conducted. Whereas the frequency and magnitude of landslides in these highlands are on the increase, the topographic attributes underpinning landslide occurrence are not well understood. Sixty-five landslide scars were surveyed and mapped to produce landslide distribution maps. Specific topographic parameters, namely slope gradient, profile curvature, topographic wetness index (TWI), stream power index (SPI), and topographic position index (TPI), were assessed on landslide slope sites. The attributes were parameterized in the field and GIS environment using a 10-m DEM. Landslides were noted to concentrate along narrow topographic hollows, as opposed to broad concave slopes in the landscape. The occurrence is dominant in slope zones where slope gradient, profile curvature, TWI, TPI, and SPI are 25°-35°, 0.1-5, 8-18, − 1-1, and > 10, respectively. It was established that profile curvature and slope gradient are the most and least significant topographic parameters in landslide occurrence (R 2 = 0.802, p value = 0.088 and R 2 = 0.5665, p value = 0.057), respectively. An understanding of these topographic underpinnings would serve to identify and predict potential landslide zones within the landscape and enhance landslide hazard mitigation.

Assessing Landslide Susceptibility by Coupling Spatial Data Analysis and Logistic Model

“…For example, T_TPI showed an elevated ability to predict the landslide, particularly the SEF. This finding is consistent with other studies [55,56], showing how the TPI is essential for slope stability analysis aiming at classifying priority zones in landslide occurrence [57]. However, the configuration of such a set of predictors is quite different among the four landslide types.…”

Topographic influence on landslides characteristics and implication for risk management in upper Manafwa catchment, Mt Elgon Uganda

“…Based on the literature of the studies in Uganda (e.g. Bagoora, 1993;Knapen et al 2006;Bamutaze 2019;Nseka et al, 2019) limited focus has been on quantitative analysis of topographic influence on the dynamics of the landslides over space and time. The selected catchment for this study, the upper Manafwa, has experienced a number of landslides but few studies undertaken (Kitutu 2010;Mugagga et al, 2012;Knapen et al, 2006;Claessens et al 2007;Ngecu et al, 2004) have concentrated on the impacts, causes such as rain fall as a triggering factor and soils.…”

Mapping the susceptibility of persons with disabilities to landslides in a highland landscape of Bushika Sub County, Mount Elgon, Eastern Uganda

“…The mid altitudes of 1500 m – 1800 m are classified to be more susceptible to landslides. Besides, sites with higher stream power indices (SPI) tend to be more erosive, and therefore have higher risks of gulley formation and consequently detonating downslope debris movements (Nseka, Kakembo & Mugagga 2019 ). Also, landslide risk increases with slope gradient and then reduces at steeper slopes (Bamutaze 2019 ).…”