The Effect of Changes in Rainfall Patterns due to Climatic Change on the Cutting Slope Stability of Landslides Case in East Java, Indonesia

Abstract

This study was conducted to determine the causes of landslides that often occur on the cutting slope on the side of the Gempol-Pandaan toll road in East Java. Furthermore, this study aims to ascertain the relationship between alterations in rainfall intensity due to climatic change on slope stability. Observation of conditions in the field, topographic contour measurements, field soil testing, real-time data processing of rain intensity, and numerical simulation for parametric study were carried out to determine the effect of changes in daily rainfall on slope stability. Also, numerical analysis using limit equilibrium as well as finite element methods with SEEP/W and SLOPE/W was carried out. The results of field observations showed there was no rainwater collection channel in the slope area, causing the water to infiltrate into the cutting slope body. The fluctuating and increasing rainfall intensity during 90 days of observation can reduce the safety factor of slope by up to 25%. This decrease in safety factors is believed to increase when the duration and intensity of the rain increase as a result of climatic change. Therefore, the integration between the impact of climate change on alterations in rain intensity in an area needs to be considered as an effort to mitigate landslides.