Slope Stability Assessment Using Trigger Parameters and SINMAP Methods on Tamblingan-Buyan Ancient Mountain Area in Buleleng Regency, Bali

I Sinarta,Teuku Faisal Fathani,Wahyu Wilopo,Ahmad Rifa’I

doi:10.3390/geosciences7040110

Abstract

The mapping of soil movement was examined by comparing an extension of the deterministic Soil Stability Index Mapping (SINMAP) method, and an overlay method with trigger parameters of soil movement. The SINMAP model used soil parameters in the form of the cohesion value (c), internal friction angle (φ), and hydraulic conductivity (ks) for the prediction of soil movement based on the factor of safety (FS), while the indirect method used a literature review and field observations. The weightings of soil movement trigger parameters in assessments were based on natural physical aspects: (1) slope inclination = 30%; (2) rock weathering = 15%; (3) geological structure = 20%; (4) rainfall = 15%; (5) groundwater potential = 7%; (6) seismicity = 3%; and (7) vegetation = 10%. The research area was located in the Buleleng district, in particular in the ancient mountain area of Buyan-Tamblingan, in the Sukasada sub-district. The hazard mapping gave a high and very high hazard scale. The SINMAP model gave a validation accuracy of 14.29%, while the overlay method with seven trigger parameters produced an accuracy of 71.43%. Based on the analysis of the very high and high hazard class and the validation of the landslide occurrence points, the deterministic method using soil parameters and water absorption gave a much lower accuracy than the overlay method with a study of soil motion trigger parameters.

Highlights

There is a high demand for public information related to spatial planning and environmental protection against landslide hazards, and as such landslide-related hazard assessment has become the main tool in risk management and an integral part of land-use planning in disaster-prone areas [1,2].Zoning of landslide hazards is associated with the environmental conditions involved in homogeneous land sharing
The primary purpose of this paper is to present a landslide hazard assessment by comparing the deterministic and semi-quantitative methods around the ancient mountainous area of Tamblingan-Buyan in Buleleng, so that the most relevant methods in the area can be identified and applied under the same location conditions
The impairments draw attention to those conditions which must be considered in the case of previously unbuilt ground [20]

Summary

Introduction

There is a high demand for public information related to spatial planning and environmental protection against landslide hazards, and as such landslide-related hazard assessment has become the main tool in risk management and an integral part of land-use planning in disaster-prone areas [1,2]. Zoning of landslide hazards is associated with the environmental conditions involved in homogeneous land sharing. Hazard assessments are usually indicated on a map which displays spatial distributions or hazard class zones [3,4]. The probability of landslide events is still difficult to clarify in most of the hazard maps due to different environmental conditions and the scarcity of previous landslide events or historical events [4,5]. Most of the published hazard maps present only spatial information of landslide hazards and do not provide an estimate of when a landslide may occur

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Conclusion