**2. Study Area**

The surrounding area of the Pinios artificial lake was selected for investigation in this study. It is located in the western part of Greece and the northwestern part of geographical area of Peloponnese (Figure 1), covering a total extent of approximately 239 km2. It belongs administratively to the Prefecture of Ilia and hydrologically to the drainage basin of Pinios River. The boundaries of the study area are defined in the north and south by the basin's boundaries, and in the west and east by altitude contours of 100 and 200 m, respectively. The Pinios artificial lake was created in 1960, after the construction of a dam on the homonym river, and is the largest in Peloponnese (with a total extent of approximately 20 km2). Its water is used for the irrigation of the plain of Ilia, and hence it is considered one of the most important land improvement projects in the entire prefecture. The total quantity of water withdrawn from the lake annual for irrigation and water supply purposes amountsto126millionm3.

**Figure 1.** The study area and the locations of events from the landslide inventory.

Following the typical landscape of Ilia Prefecture, the study area can be characterized as an agricultural region at a low altitude (mean altitude at 154 m above sea level). Heterogeneous croplands or fields mixed with natural vegetation represent the predominant agricultural lands. More than 30 settlements are situated within its boundaries, containing 5400 inhabitants according to the official 2011 census [39].

The climate is Mediterranean mild with a mean temperature ranging from 20 to 25 ◦C in the summer months, and from 4 to 10 ◦C in the winter months [40]. Long-term rainfall records including the period of the last two decades show a mean annual value reaching approximately 500 mm. From a geological perspective, the study area is mainly covered by Neogene and Quaternary loose deposits varying in thickness and consistency. Confined granular aquifer systems have been formed inside alluvial deposits, and unconfined aquifers have been developed in Quaternary deposits where groundwater flows to the direction of the sea [41].

#### **3. Data and Methods**

In this study, a hybrid model was developed for LS assessment based on the integration of two different individual models, the GeoDetector and IV. A spatial database was created in GIS to be used in hybrid modeling, including: (a) the landslide inventory dataset and (b) the conditioning factor datasets.
