Soil Micromorphology of Land Cover in Landslide Susceptibility Area in Kelara Subwatershed, Jeneponto, Indonesia

Abstract

Background and Objective: External factors such as lithology, climate, slopes, land cover and soil have been carried out to provide solutions in anticipating and responding to land degradation, but disasters still occur. So it is imperative to see the impact of internal soil factors on some potential land use land cover in this area to answer and anticipate the effects of climate change in predicting the susceptibility of the soil to disasters. This study aims to study the soil micromorphology of some land cover in the landslide susceptibility area of the Kelara Subwatershed in Rumbia District, Jeneponto Regency of South Sulawesi. Materials and Methods: The study is descriptive exploratory through field surveys and supported by data from laboratory analysis. Laboratory analyses include soil texture analysis, particle density, bulk density, porosity, permeability and thin section analysis for micromorphological observations in soil. Results: The clay fraction content increased >25% in all land cover due to increased rainfall since 2010, which triggered an increase in soil mineral weathering activity. Land use for mixed plants showed a significant increase in clay >30% and plane voids. Permeability in the mixed plant reached 0.42 cm hrG 1 with category very slow has significantly different from another land cover and induced landslide. Conclusion: Increasing clay and decreasing soil permeability trigger the formation of plane voids which cause the soil to undergo a micro shrinking and slipping process and internal micro-shifts. It is the key to improving soil susceptibility to landslides in mixed plant land use in the sloping area.

Soil micromorphology for modeling spatial on landslide susceptibility mapping: a case study in Kelara Subwatershed, Jeneponto Regency of South Sulawesi, Indonesia

“…1). The average annual rainfall for 20 years (2000-2020) is 2552.45 mm/year (Ahmad et al 2022a). Land cover in the study area consisted of shrubs at 0.27%, forest at 1.82%, settlement at 1.73%, dryland farming at 9.80%, mixed dryland farming at 77.66%, rice elds at 7.96%, and bareland at 0.72%.…”

“…The micromorphological characteristics of the soil that can trigger landslides are the formation of plane voids (micro cracks), striated b-fabric, and a high percentage of clay fractions which have reduced soil resistance (Yurong et al 2006;Ahmad et al 2018). The formation of plane voids due to soil swell activity can be used as one of the parameters in assessing the potential for landslides (Ahmad et al 2022a).…”

“…Soil parameters have been used by several researchers in assessing landslide susceptibility, especially soil texture, macro-micro porosity, and erodibility (Fonseca et al 2017b;Conforti and Ietto 2021). The addition of soil micromorphology data in the form of plane voids has signi cantly affected the physical occurrence of landslides at the study site (Ahmad et al 2022a). The spatially adding soil organic carbon, soil texture, soil erodibility, and soil micromorphology data (Fig.…”

“…Increasing soil clay fraction has also been shown to increase soil's erodibility against landslides in the Kelara Sub-watershed (Ahmad et al 2022b). Previous studies have proven the formation of planar planes and microstructures in landslide-prone areas (Yurong et al 2005;Ahmad et al 2022a), and it is not formed in locations categorized as high class of landslide susceptibility with the AHP method (Amin et al 2021). So it is necessary to add soil micromorphological parameters in mapping the level of susceptibility of the soil that triggers landslides using the spatial regression model so that the resulting susceptibility map data can be accurate in determining the susceptibility class.…”