GIS-based gully erosion susceptibility modeling, adapting bivariate statistical method and AHP approach in Gombe town and environs Northeast Nigeria

Abstract

Gully erosion is a major environmental problem in Gombe town, a large area of land is becoming unsuitable for human settlement, hence the need for a gully erosion susceptibility map of the study area. To generate a gully inventory map, a detailed field exercise was carried out, during this investigation one hundred gullies were identified and studied extensively within the study area of about 550 km2. In addition to the mapped gullies, Google EarthPro with high-resolution imagery was used to locate the spatial extents of fifty (50) more gullies. Ten gully erosion predisposing factors were carefully selected considering the information obtained from literature, and multiple field survey of the study area, the factors include elevation, slope angle, curvature, aspect, topographic wetness index (TWI), soil texture, geology, drainage buffer, road buffer and landuse. In this study, a GIS-based Frequency Ratio (FR) and Analytical Hierarchy Process (AHP) models were employed to predict areas prone to gully erosion in Gombe town and environs. The result obtained from FR shows that drainage, soil texture, and slope have the highest correlation with gully occurrence, while the AHP model revealed that drainage buffer, soil texture, geology have a high correlation with the formation of a gully. Gully erosion susceptibility maps (GESM) were produced and reclassified into very high, high, moderate, and low zones. The overall accuracies of both models were tested utilizing area under the curve (AUC) values and gully density distribution.FR and AHP model have AUC values of 0.73 and 0.72 respectively, the outcome indicates that both models have high prediction accuracy. The gully erosion density distribution values revealed that gullies are concentrated in the very high susceptibility class and it decreases towards the low class, therefore the GESM produced using these models in this study area is reliable and can be used for land management and future planning.

Evolution and Trend of Research on the Hydrogeomorphological Processes on Roads in the Last Decades: a Review

“…As technology advanced, several models were created and used to analyze both quantitatively and qualitatively the rate of soil erosion on roads. However, in recent years researchers have used geostatistical methods to collect information about environmental processes on roads (Ezekwesili & Agunwamba 2021;Igwe et al 2020) (see keywords in Figure 5).…”

Integration of Geospatial Technology and AHP knowledge Based Technique in Preparation of Susceptibility Modelling to Gully Erosion: A Study from Cratonic Part of Eastern India

“…Soil texture is a function of sub-surface ow and piping, and the formation of gullies starts when the top of the pipes falls down (Igwe et al 2020). The study of interest mainly forms four consecutively four distinct soil group from west to east (Fig.…”

“…The occurrence of gully signi cantly depends on lithological properties. The geological map gives impression of underlying lithology (Igwe et al 2020). The river basin owns different types of rocks of different geological formations from Proterozoic to Quaternary (Karmakar et al 2021).…”

Scrutinizing gully erosion hotspots using hybridized deep‐learning analysis to avoid land degradation

“…Knowledge‐based models consider multi‐criteria analysis based on experts' expertise and questionnaires. The analytical hierarchy process (AHP) is one of the commonly used knowledge‐based models for analyzing gully susceptibility (Dandapat et al, 2020; Igwe et al, 2020). As the main drawbacks of the knowledge‐based models, they do not work based on a real gully erosion inventory and are characterized by subjectivity bias (Al‐Bawi et al, 2021).…”