## 2 Materials and Methods
### Data Preparation and Analysis
#### 2.3.2 Landslide Causal Factors
When the ranges of the distance to rivers were [0,150) and [150,300), the information values were the largest, being 1.910 and 1.333, respectively (Table 1). 14. Distance to guil  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Causal Factor** & **Category** & **Pixels in Landslide** & **Pixels in TD** & **Proportion of LTL** & **Proportion of DTD** & **IV** & **NC** \\ \hline \multirow{4}{*}{Altitude (m)} & \(<\)300 & 17,324 & 81,071 & 68  
Figure 2: _Cont._  
The gully can erode the foot of the slope on the two banks. The distance to the gully was used to characterize its action intensity, which was divided into five grades (Figure 2m): [0,150], [150,350], [350,500], [500,900], and [900,3000]. The gully can promote the development of a landslide. When the ranges of the distance to the gully were [0,150] and [150,350], the information values were 0.285 and 0.182, respectively (Table 1). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Category** & **Main Lithology** & **Geologic Group** \\ \hline A & Silstone, silty mudstone & T\({}_{2}\)b\({}^{2}\) \\ B & Silstone, muddy limestone, dolostone with mudstone & T\({}_{2}\)b\({}^{3}\), T\({}_{2}\)b\({}^{4}\) \\ C & Mudstone, muddy limestone & T\({}_{2}\)b\({}^{1}\) \\ D & Sandstone, silty shale & T\({}_{3}\)d\({}^{1}\), T\({}_{3}\)e \\ E & Muddy limestone with limestone & T\({}_{1}\)d\({}^{1}\), T\({}_{1}\)d\({}^{2}\), T\({}_{1}\)d\({}^{3}\), T\({}_{1}\)d\({}^{4}\) \\ F & Limestone with dolostone, muddy limestone, dolomitic limestone & T\({}_{1}\)j\({}^{1}\), T\({}_{1}\)j\({}^{3}\), T\({}_{1}\)j\({}^{4}\) \\ G & Limestone, silty shale with coal seam & P\({}_{3}\)w, P\({}_{3}\)d \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Lithological classification in the study area. \begin{table}
\begin{tabular}{c c} \hline \hline
**Category** & **Definition (slope:\(\theta\), aspect:\(\sigma\), bed dip angle:\(\alpha\), bed dip direction:\#)** \\ \hline BS1 & \(\alpha<10^{\circ}\) \\ BS2 & \(\left(\left(\left|\alpha-\beta\right|\in(0,30^{\circ}]\right)\mathbb{I}\left( \left|\alpha-\beta\right|\in[330^{\circ},360^{\circ})\right)\right)\&\&\&\(\left(\alpha>10^{\circ}\right)\&\&\left(\theta>\alpha\right)\) \\ BS3 & \(\left(\left(\left|\alpha-\beta\right|\in(0,30^{\circ}]\right)\mathbb{I}\left( \left|\alpha-\beta\right|\in[330^{\circ},360^{\circ})\right)\right)\&\&\&\(\left(\alpha>10^{\circ}\right)\&\&\left(\theta=\alpha\right)\) \\ BS4 & \(\left(\left(\left|\alpha-\beta\right|\in(0,30^{\circ}]\right)\mathbb{I}\left( \left|\alpha-\beta\right|\in[330^{\circ},360^{\circ})\right)\right)\&\&\&\(\left(\alpha>10^{\circ}\right)\&\&\left(\theta<\alpha\right)\) \\ BS5 & \(\left(\left|\alpha-\beta\right|\in[30^{\circ},60^{\circ})\right)\mathbb{I}\left( \left|\alpha-\beta\right|\in[300^{\circ},330^{\circ})\right)\) \\ BS6 & \(\left(\left|\alpha-\beta\right|\in[60^{\circ},120^{\circ})\right)\mathbb{I} \left(\left|\alpha-\beta\right|\in[240^{\circ},300^{\circ})\right)\) \\ BS7 & \(\left(\left|\alpha-\beta\right|\in[90^{\circ},150^{\circ})\right)\mathbb{I} \left(\left|\alpha-\beta\right|\in[210^{\circ},240^{\circ})\right)\) \\ BS8 & \(\left(\left|\alpha-\beta\right|\in[120^{\circ},180^{\circ})\right)\mathbb{I} \left(\left|\alpha-\beta\right|\in[180^{\circ},210^{\circ})\right)\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Classification of bedding structure. Figure 2: Landslide causal factors of the study area: (**a**) slope, (**b**) aspect, (**c**) curvature, (**d**) plan curvature, (**e**) profile curvature, (**f**) SPI, (**g**) TWI, (**h**) TRI, (**i**) lithology, (**j**) bedding structure, (**k**) distance to faults, (**l**) distance to rivers, (**m**) distance to gully.