| Abstrak/Abstract |
In order to ensure the safety of the visitors, the development planning of tourism areas requires a comprehensive study on the physical condition and disaster risk management, so that it can be applied effectively, efficiently, and in line with the sustainability requirements. In this case, the study on the physical condition focuses on the potential of natural disasters, especially landslide. This research was conducted in Terunyan Village, Kintamani Distric, Bangli Regency, Bali. Landslide often occurs in this village, especially during the rainy season, as it is surrounded by hills with low vegetation and bordered by a lake. Samples were collected from two hand bore points at slopes which have the highest risk to the public facilities and residences. GeoStudio 2012 program was used to analyze the rainfall infiltration, then it was linked to Slope/W to obtain the safety factor. The average rainfall intensity applied in this study was 125 mm/day, and the optimal duration of rain was 5 hours (based on the data provided by BMKG on 9 February, 2017). The results show that the impact of rainfall to the infiltration with the safety factor lower than 1.0 happened in the 2nd hours. The critical safety factor decreased from 0.963 to 0.623. The safety factor decreased drastically in the 4th to 5th hours of rain due to the drastic drop of the resisting force from 167 kPa to 124 kPa and the increase of driving force from 152 kPa to 200 kPa. The high and constant rain volume caused
high seepage to the ground. Rain water filled the soil void and increased the pore pressure, then the soil became saturated and the internal friction angle decreased. This problem can be solved by controlling the seepage into the ground, which can be done by closing the open cracks and designing the upperground and underground drainage system. |
