The level of slope influenced by the condition of the rocks beneath the surface. On high level of slopes, amount of surface runoff and water transport energy is also enlarged. This caused by greater gravity, in line with the surface tilt from the horizontal plane. In other words, topsoil eroded more and more. When the slope becomes twice as steep, then the amount of erosion per unit area be 2.0 - 2.5 times more. Kuok and surrounding area is the road access between the West Sumatra and Riau which plays an important role economies of both provinces. The purpose of this study is to map the locations that have fairly steep slopes and potential mode of landslides. Based on SRTM data obtained, the roads in Kuok area has a minimum elevation of + 33 m and a maximum + 217.329 m. Rugged road conditions with slope ranging from 24.08 ° to 44.68 ° causing this area having frequent landslides. The result of slope stability analysis in a slope near the Water Power Plant Koto Panjang, indicated that mode of active failure is toppling failure or rock fall and the potential zone of failure is in the center part of the slope.

Kampar rivers has a length of 413 km with average depth of 7.7 m and width of 143 m. Sixty percent of this rivers are meandering fluvial system which transport and deposit a mixture of suspended and bed-load (mixed load) along low energy. River channel that moving sideways by erosion is undergoing lateral migration and the top of the point bar becomes the edge of the floodplain and the fining-upward succession of the point bar will be capped by overbank deposits of Kampar River. Along the Kampar Rivers, there are more than 60% of floodplain sediments and almost all of the floodplain formed by bend migration on the suspended-load channels of Kampar watershed. This formation consist of succession of fine to medium sand and silt/mud, with root traces, that form as drapes on the prograding bank. These beds dip mostly channel wards and quickly wedge out as they grade up and onto the floodplain. The depositional model is presented showing how lateral accretion can make a significant contribution to the preservation of fine-grained within channel deposits in contemporary floodplains. The examples presented here demonstrate that analogues to ancient point-bar deposits containing alternating sandstone and shale sequences are common in the low-energy fluvial environments of Riau rivers especially Kampar rivers.

This study aimed to observe the characteristics of sea surface temperature (SST) and wind velocity and its relation with the Indian Ocean Dipole (IOD) in the waters of Batam. The data used in this study were the SST datasets and the wind speed of 2016 in the waters of Batam. The method used in this research were the visual analysis using the data ocean view (ODV) to observe at the spatial and temporal distribution of the SST and the wind speed in Batam waters at different seasons. The next method is a fast Fourier transform (FFT). The earlier monsoon season that occurred in April has the highest wind speed with the value of 3.9 MS ** ^{- 1} for components U. As for the V, the component has the highest value of -3.6 MS ** ^{- 1}. The SST Batam observed high in April occurred on 19-04-2016 with a value of 304.2 ° K (31.05 ° C). West monsoon winds that occurred in January has the highest wind speed with a value of 4.5 MS ** ^{- 1} for components U. As for the V, the component has the highest value of 5.2 MS ** ^{- 1} in the waters of Batam. The highest SST in Batam was occurred in January on 19-01-2016 with a value of 302.8 ° K (29.65 ° C). Based on the results of the FFT, wind speed and SST in the waters of the Island has a dominant 6-month period (semiannual).

The geological disaster of landslide has occurred in Merangin Village, Kuok Subdistrict, Kampar Regency, Riau Province which located exactly in the national road of Riau - West Sumatra at Km 91. Based on the occurrence of landslide, this research was conducted to study geological structure and engineering geology to determine the main factors causing landslides. Based on measurement of the structural geology found on research area, there were fractures, faults and fold rocks which having trend of stress N 2380 E, plunge 60, trending NE-SW direction. Several faults that found was normal faults directing N 2000 E with dip 200 trending from northeast-southwest and reverse fault impinging N 550 E with dip 550, pitch 200 trending to the northeast. Fold structures showing azimuth N 2010 E trending southeast-northwest. From geological engineering analysis, the results of scan line at 6 sites that have RQD value ranges 9.4% - 78.7 % with discontinuity spacing 4 - 20 cm. So, It can be concluded that the formed structure was influenced by the extensive northeast-southwest tectonic phase, then continued through north-south tectonic phase, and ended by a tectonic period with directing from northeast-southwest. Rock Mass Rating classification showing value 62 – 76, Which also resulted that rocks in the study area have weathered on the outside but still in good condition (good rock). However, This condition of structure has caused the formation rocks producing weak zone that became one cause of the occurrence of landslides.

Rockwall retreat by rockfalls in high alpine mountains has received increasing attention due to the increased rock failure activities and the corresponding damage under global warming in the past 20 years. However, the face retreat by rockfalls of subalpine rock cliffs is not sufficiently monitored and analyzed. In the present work, the nearly vertical sandstone-marls Molasse cliff formed by the La Cornalle-Les Luges landslide was monitored by a three-year monthly drone-based SfM photogrammetry and TLS scanning to establish the rockfalls inventories. The cumulative monthly detachment volumes from the sandstone and marls layers were analyzed using the frequency-magnitude relationships fitted by a negative power law, respectively, which help to calculate the retreat rate and reveal the spatiotemporal evolution of rockfalls between these two layers. Meanwhile, the cliff retreat volume in different months was correlated to the environmental factors (e.g., air temperature, precipitation, and rock surface temperature) using linear regression. A weather station and thermal couples in the rock collected the data of these factors. As a result, this work will contribute to a better understanding of the retreat pattern and rate of freshwater Molasse walls under global warming and provide a rock detachment model on a cliff with interbedded hard and soft rock layers in the subalpine regions.

The bathymetry mapping using underwater acoustic technology very important in Indonesia waters. Bathymetry is the result of measuring the height of the seabed so that the bathymetric map provides information about the seabed, where this information can provide benefits to several fields related to the seabed. In bathymetry mapping uses underwater acoustic technology where among them is using Single beam echosounder and MBES (Multibeam Echosounder System), and multibeam echosounder (MBES) is acoustic equipment that is intensively used frequently in basic waters mapping. The advantage of using underwater acoustic technology is the acquisition and processing of data in real time, high accuracy and precision (correction of the bathymetry data was carried out with reference to the 2008 International Hydrographic Organization (IHO), and cannot be a threat or damage to objects. Retrieval of bathymetry data must use parallel patterns, namely: patterns with perpendicular sounding directions and tend to be parallel to longitudinal lines or in accordance with parallel sounding patterns.