# Influence of Earthquakes on Landslide Susceptibility in a Seismic Prone Catchment in Central Asia
## 1 Introduction
Applications, such as CLARA [30], 3D-SLOPE [31], the script from [PERSON] et al. [18], r.rotstab [32], Scoops3D [33], and OpenLISEM [34], were developed for this purpose. In this study, Scoops3D was selected because this model is designed to simulate the LSI and VOL resulting from a series of plausible scenarios, such as the effects of different intensities of earthquakes [33]. The development of land sliding is one of the most complex geomorphological processes, and has potential relationships with the topographic variables (e.g., elevation, slope, and aspect), land cover, soil type, precipitation pattern, and possibly also proximity variables (e.g., distance to faults, roads, and streams) [19; 35; 36; 37]. Topography is one of the critical variables in the landslide phenomenon: elevation determines the temperature gradient and the distribution of vegetation [38; 39]; slope and aspect are related to the exposure to sunlight and drying wind, and they can influence the soil moisture and the distribution of vegetation [13]. Slope stability is also strongly influenced by land cover; for instance, due to a strong rooting system, forest trees can enhance the slope stability [40; 41]. Soil characteristics are another crucial controlling variable for the occurrence of landslides, because each soil type has its own susceptibility rate [42]. Intensive rainfall events can also increase the probability of landslides in mountainous areas [35; 43; 44]. Moreover, the proximity variables are related to lineament, anthropogenic activities, and erosion processes [36; 37; 45]. However, the relative importance of these environmental variables is different and varies from catchment to catchment. The determination of the most important variables can allow the limited human power and budget to be investigated in terms of maintenance and improvement of the most important variables and their conditions, and it can also assist the engineering plan by avoiding unstable areas (e.g., in the proximity of faults or specific topographic areas). As a result of landslides, developing countries are facing more devastating consequences due to poor infrastructure and the lack of hazard management systems [13], for example, Kyrgyzstan and the surrounding neighbours within the Tien Shan Mountains [46; 47]. The Tien Shan Mountains are frequently affected by seismic activities (e.g., earthquakes) [48], and several strong earthquakes struck this area and its surroundings during the last century, such as the Kemin earthquake in 1911 with a magnitude of 7.7 (or M 7.7), the Chatkal earthquake in 1946 (M 7.6), the Khait earthquake in 1949 (M 7.4) and the Suusamy earthquake in 1992 (M 7.3) [49]. One hotspot of earthquakes and landslides in the Tien Shan area is the Ferghana Valley, where the studied Mailuu-Suu catchment (Figure 1c) is located [50; 51]. In the Kyrgyz part of the Ferghana Valley, the first recorded massive activation of landslides occurred in 1954 and was followed by other events in 1958, 1969, 1979, 1988, 1993-1994, 1998, 2003-2005, and 2017 [50; 52]. The studied Mailuu-Suu catchment (Figure 1) and its neighbouring areas are also frequently affected by earthquakes [48; 50]. For example, the recorded strongest earthquake (M 6.6 with a depth of 49.5 km) struck the Jalal-Abad region (30 km far from the Mailuu-Suu catchment) on 19 August 1992, and it cost the lives of 54 people, directly affected 86,800 people, and resulted in an economic loss of approximately USD 130 million [53]. Besides the effects of earthquakes and landslides, the Mailuu-Suu catchment and the nearby regions (e.g., Min-Kush and Shekaftar in the Kyrgyz Republic, Charkesar and Yangiabad in the Republic of Uzbekistan, as well as Degmas and Istikl in the Republic of Tajikistan) are exposed to another important environmental problem, namely a high risk of radioactive contamination resulting from a large portion of radioactive wastes (e.g., tailings ponds and dumps with radionuclides like Ra-226, Pb-210, Po-210, and U-238) [50; 54]. After 1995, the conventional mines were closed [55].