**2. Materials and methods**

#### **2.1 Study area**

The current study area is in the Birbir Mariam district of Ethiopia's Gamo highlands, in the rift valley escarpments. It is approximately 450 km from Addis Ababa's capital city and 47 km from the Zonal capital of Arba Minch town. It has a total area of 110 km2 and is geographically bounded (UTM Zone 37 N) by latitudes ranging from 692,000 to 702,000 m N and longitudes ranging from 342,000 to 360,000 m E. The area can be reached from Arba Minch town via the Chencha-Ezo main road and the Birbir Mariam gravel road (**Figure 1**).

The study area's geological setting has a significant impact on the occurrence of landslides. Since the Oligocene, volcanoes have been active in the southern part of the *Landslide Assessment and Hazard Zonation in the Birbir Mariam District, Gamo Highlands… DOI: http://dx.doi.org/10.5772/intechopen.108122*

**Figure 1.** *Location map of Birbir Mariam district.*

Main Ethiopian Rift (MER), which includes the Ganjuli graben (Lake Abaya), and the western side of Lake Abaya, which includes the plateau and the Chencha escarpment [37–39]. The geology of the study area is dominated by pre-rift and post-rift deposits. Thereby, the stratigraphy [38, 40] has the following significant units in the Galena basin and north Abaya basin. These are ignimbrite, unwelded tuff units, early flood basalts, alkaline basalt intermediate flows, pyroclastic rocks, Pleistocene basalt, trachyte, and rhyolites.

The geology of the research area can be mapped using field investigations. Basalt, tuff, and Ignimbrite are among the geologic units found in the study area (rock units). The measurement's rock units can be present along rivers, road cuts, and natural hillsides. Overall, the dominance of destructive materials, basalt, and ignimbrite is a crucial feature of the lithologies of this region (**Figure 2**).
