| Penulis/Author |
Dr. Eng. Guruh Samodra, S.Si., M.Sc. (1) ; Muhammad Fauzan Ramadhan (2); Prof. Dr. rer. nat. Junun Sartohadi, M.Sc. (3); Dr.rer.nat Muhammad Anggri Setiawan, M.Si (4); Dr. Nugroho Christanto, S.Si., M.Si. (5) |
| Abstrak/Abstract |
Preliminary knowledge of the surface movement and
internal structure of a landslide is essential to improve the understanding of landslide behavior as an initial step to develop suitable
mitigation measures. This paper characterizes displacement and
internal structure of landslides using multitemporal unmanned
aerial vehicles (UAV) and electrical resistivity tomography (ERT)
imaging. Multitemporal orthophotos, digital elevation model
(DEM) profile lines, DEMs of difference (DoD), and ERT images
allowed us to measure the landslide morphometry and areal
changes, detect the trend of surface displacement, calculate the
surface movement rate and direction, characterize the spatial
variability in surface movement rates, and relate spatial variation
in displacement to the internal structure of the landslide. The
Kalisari Landslide experienced retrogressive movement where
the scarp of landslide moved backward 38 m from 2015 to 2019.
The surface movement ranged from 0.7 to 8.1 m with the direction
mostly to the northeast. The depletion and accumulation ranged
from 0.1 to 5 m, with the most active change located northwest of
the landslide. The variability in movement was influenced by the
spatial variability in the subsurface material inferred from the ERT
images, i.e., surface material, clay, weathered breccias (possibly
altered), and breccias. The interpretation from multitemporal
UAV and ERT images indicates that the Kalisari Landslide has a
nonhomogeneous multiple retrogressive behavior with a curved
slip surface located at the clay layer. |
