Flash flood led to high levels of water in the urban areas, causing many problems such as bridge collapse, building damage and the victim died. It is impossible to avoid risks of floods or prevent their occurrence, however, it is plausible to work on the reduction of their effects and to reduce the losses which they may cause. The objective of this paper is to generate a flash flood map in Suoh region, using satellite images, UAVs images and GIS tools. Analytical Hierarchical Process is used to determine the relative impact weight of flood causative factors to get a composite Flood Hazard Index (FHI). The causative factors in this study are flow accumulation (F), rainfall intensity (I), geology (G), land use (U), slope (S), and elevation (E). The presented methodology has been applied to an area in Suoh region, where recurring flood events have appeared. Initially, FIGUSE method resulted in an FHI and a corresponding flood map. A sensitivity analysis on the parameter’s values revealed some interesting information on the relative importance of each criterion, presented and commented in the discussion section.

Gravity research in the Rajabasa geothermal prospect area was conducted to determine geothermalreservoirs and faults as reservoir boundaries. The research includes spectrum analysis and separation of the Bouguer anomaly to obtain a residual Bouguer anomaly, gradient analysis using the second vertical derivative (SVD) technique to identify fault structures or lithological contact, and 3D inversion modeling of the residual Bouguer anomaly to obtain a 3D density distribution subsurface model. Analysis was performed based on all results with supplementary data from geology, geochemistry, micro-earthquake (MEQ) epicenter distribution map, and magnetotelluric (MT) inversion profiles. The study found 3 (three) geothermal reservoirs in Mount Balirang, west of Mount Rajabasa, and south of Pangkul Hot Spring, with a depth of around 1,000-1,500 m from the ground level. Fault structures and lithologies separate the three reservoirs. The location of the reservoir in the Balirang mountain area corresponds to the model data from MEQ, temperature, and magnetotelluric resistivity data. The heat source of the geothermal system is under Mount Rajabasa, which is indicated by the presence of high-density values (might be frozen residual magma), high-temperature values, and the high number of micro-earthquakes epicenters below the peak of Mount Rajabasa.

Shear Wave Splitting is an application of seismic wave to analyse the anisotropy level of a certain medium. Generally, shear wave propagation through a rock formation will be polarized (φ) into two parts especially when the medium structures are different, such as fracture. The polarized shear wave which is perpendicular to fracture will propagate slower than the wave that propagates parallel to the fracture. The delay time (δt) of both wave is proportional with the fracture intensity along the wave propagation from the source to the station. The description regarding fracture orientation can be obtained by analysing both Shear Wave Splitting parameters (φ and δt), and this information is adequately important in geothermal exploration or exploitation phase at Mt. Amiata. Based on the result of this research, the micro earthquake source is focused on the east to the south area and spread along 3 earthquake stations. The existence of micro earthquake source is mainly focused at the depth of 1 to 4 km. In addition, the polarization direction of each earthquake station at the geological map shows a dominant fracture orientation consistently at NW-SE. All of the three stations also show that the polarization direction is integrated to the local fault existence in the subsurface. Furthermore, the research shows that the high intensity fracture distribution occurred at MCIV station area in the southern part of research location. Meanwhile, the low intensity fracture distribution occurred at ARCI and SACS station area in the western and the eastern part of research location. The high value of fracture intensity accompanied by the high amount of structure intensity, strengthen the prediction of the high anisotropy existence which potentially tends to the high permeability presence at the area.Keywords: shear wave splitting, anisotropy, fracture, geothermal, polarization direction, fracture intensity.

Desa wisata Pagar Jaya memiliki beberapa obyek geowisata yang sangat menarik untuk dikunjungi seperti: Dinding Dasit, Pantai T. Indah, Pantai T. Hantu, dan Batu Wayang. Semua obyek geowisata tersebut berada di area pesisir dan sangat rentan terhadap ancaman bencana tsunami. Nilai penting dari proses partisipatif dalam kajian risiko bencana adalah  mewadahi masyarakat dalam mengambil keputusan dan merumuskan tindakan prioritas pengurangan risiko bencana. Tujuan dari pengabdian ini adalah: memetakan kondisi eksisting obyek geowisata Dinding Dasit, Teluk Indah, Teluk Hantu, dan Batu Wayang berbasis geospasial, mengedukasi masyarakat akan prinsip-prinsip mitigasi bencana tsunami, dan mengintegrasikan data geospasial dan nonspasial dari kelompok masyarakat dalam pembuatan jalur evakuasi bencana tsunami di Desa Wisata Pagar Jaya. Kelompok masyarakat yang tergabung dalam Kelompok Sadar Wisata (Pokdarwis) Desa Wisata Pagar Jaya merupakan subjek utama dalam proses pemetaan partisipatif. Proses pemetaan melalui tahap Focus Group Discussion dan in-depth interview berkaitan dengan risiko bencana dan jalur evakuasi. Sistem Informasi Geografis kemudian mentransformasikan hasil pemetaan partsipatif dalam bentuk digital. Hasil dari penelitian ini adalah peta partisipatif jalur evakuasi untuk bencana tsunami di Desa Pagar Jaya yang secara geografis berada di pesisir selatan Pulau Sumatera.

Suoh merupakan daerah tektonik aktif yang mengakibatkan terbentuknya struktur geologi yang tersebar di Daerah Suoh. Struktur geologi yang berkembang di Daerah Suoh telah dianalisis menggunakan data gaya berat dan data DEM ALOS PALSAR untuk menentukan dan menganalisis struktur geologi serta arah dominannya. Analisis struktur bawah permukaan menggunakan metode gaya berat dengan analisis Second Vertical Derivative (SVD) dan analisis kelurusan menggunakan metode Fault Fracture Density (FFD). Kontur SVD residual bernilai 0 dan area dengan nilai FFD tinggi (2 sampai 2,6 km/km²) mengindikasikan adanya struktur sesar dangkal. Berdasarkan analisis kelurusan data DEM telah didapatkan informasi tentang kelurusan berarah barat laut-tenggara yang sangat jelas, selaras dengan struktur geologi regional daerah Suoh.