GIS-Based Risk Assessment and Mitigation of Road Slope Instability in Morotai Island Regency

Abstract

Road slope inventory is one part of the integrated activities in a road slope management system, together with inspection, risk assessment, risk level mitigation, road slope database and maintenance. The road slope management system is equipped with a series of inseparable guidelines. Road slope inventory is carried out by collecting road slope data which includes slope geometry and dimensions, slope engineering construction and slopes with failures on a road section. The aim of this research is to identify and analyze the risk level assessment and mitigation of potential slope failures that impact the function of National roads in Morotai Island Regency. This research method includes an inventory of road slopes starting with determining the location, collecting and reviewing secondary data, and identifying the condition of each road slope based on the inventory form. The risk level assessment indicators used in this research include: general site, road slope geometric, slope geology, road slope, road slope engineering construction, condition slope site collapses, road body and shoulder, drainage, instrumentation. This identification was carried out at 10 points that had a slope height greater than 5 m. Based on the research results, it was found that the slope risk level on the national road section in Morotai Island Regency was with the highest risk found on the Daeo/Sangowo – Bere Bere road section (61-021-001-A) with the type of collapse being rock falls and a risk value of 84.9, then the road section with the lowest risk is the Sopi – Wayabula 1 road section (61-0231-001-A) with the type of collapse in the form of rock falls with a risk value of 39.1. The results of the inventory of potential road slope collapses in this research were then visualized through mapping using a Geographic Information System-based application. This will make it easier for stakeholders to make policies in road slope management.