# Study on Temporal and Spatial Distribution of Landslides in the Upper Reaches of the Yellow River
## 3 Temporal and Spatial Distribution of Landslides in the Upper Reaches of the Yellow River
### Spatial Geometric Distribution Characteristics of Landslide
The length of the landslide in the study area spans a large range, with a minimum length of 120 m and a maximum length of 6500 m, mostly between 500 and 2200 m. Mainly concentrated in the 550-1500 m, there are 388, accounting for 76.4% of the total number of landslides; especially in the length of 550-1000 m landslides have 165, accounting for 32.5% (Table 4). The width of the landslide is also large, the minimum width is 90 m, the maximum is 7200 m, mostly 560-2500 m, mainly concentrated at 600-1500 m, there are 405, accounting for 79.7% of the total number of landslides (Table 5). Figure 5: Plane morphological characteristics of landslide in the study area. (**a**) Dumb-bell shape; (**b**) Side-by-side shape; (**c**) Saddle type; (**d**) Long arc shape; (**e**) Triangle; (**f**) Rectangle. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Number**} & **Plane** & **Representative** & **Latitude and** & **Remote Sensing** & **Plane Morphological** \\  & **Configuration** & **Landside** & **Coordinates** & **Image Type** & **Characteristics** \\ \hline a & Dumb-bell shape & Kuogeza landslide & \(101^{\circ}36^{\prime}\) E, \(36^{\circ}08^{\prime}\) N & Google earth & Slide length is greater \\  & & & GeoEye & than width \\ \hline b & Side-by-side shape & \begin{tabular}{c} Zhaji 'ang \\ land-slide group \\ \end{tabular} & \(101^{\circ}55^{\prime}\) E, \(36^{\circ}06^{\prime}\) N & ZY-3 & \begin{tabular}{c} Multiple single \\ landslides are \\ arranged side by side \\ \end{tabular} \\ \hline c & Saddle type & \begin{tabular}{c} Mangla River \\ estuary landslide \\ \end{tabular} & \(100^{\circ}27^{\prime}\) E, \(35^{\circ}42^{\prime}\) N & GeoEye-2 & \begin{tabular}{c} Trailing edge center \\ bend \\ \end{tabular} \\ \hline d & Long arc shape & \begin{tabular}{c} Mangla River left \\ bank landslide \\ \end{tabular} & \(100^{\circ}26^{\prime}\) E, \(35^{\circ}43^{\prime}\) N & Google earth & \begin{tabular}{c} Lateral margins and \\ pos-terior wall are \\ curved \\ \end{tabular} \\ \hline e & Triangle shape & \begin{tabular}{c} Gelongbu \\ landslide \\ \end{tabular} & \(102^{\circ}36^{\prime}\) E, \(49^{\circ}12^{\prime}\) N & Google earth & \
\begin{tabular}{c} Regular triangle or \\ geoEye \\ \end{tabular} \\ \hline f & Rectangle & Xijitan landslide & \(101^{\circ}26^{\prime}\) E, \(36^{\circ}06^{\prime}\) N & ZY-3 &
\begin{tabular}{c} Rectangular in shape \\ with an upright \\ back wall \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Representative landslide locations and image types. Statistics show that there are a large number of landslides with a length greater than the width of the sliding body, which are mainly distributed on both sides of the mainstream of the Yellow River in the Qunke-Jianzha Basin. These slopes have large height differences and open free surfaces, so it is easy to form large-length landslides, such as Xiazangtan landslide, Kangyang landslide, Lannitan landslide, Shenguotan landslide, Sozi landslide, etc., which belong to the category of giant landslides in terms of volume, belong to mudstone landslides in terms of material composition type, and are mainly in the form of ring chairs, long tongues, giants, dumbbells, etc. This type of landslide has a long sliding distance and a large sliding speed, which is a typical high-speed and long-distance landslide type [25]. The Yellow River is partially blocked, forming a huge barrier lake, leaving landslide deposits on the other side of the Yellow River, such as the Suozi landslide and the Gelongbu landslide; some landslides belong to the creep type, with a short sliding distance and a small sliding speed, such as the Shangen landslide in Gongboixaikou. Meanwhile, landslides with width greater than length are mainly distributed in the Gonghe Basin on both sides of the main stream of the Yellow River, such as the Baicitan landslide, the Mangla River left bank landslide, and the Mangla River estuary landslide.