## 3 Analysis of the Main Geomorphological Features of the Pit Rim Structure
### Slope and Aspect Analysis
#### 3.5.2 Aspect Analysis  
Combined with the classification of the aspect (Figure 13b) and the statistical results of the aspect frequency (Figure 13d), the mean slope aspect was 170.26\({}^{\circ}\) (south direction), the \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Ridge ID**} & \multicolumn{8}{c}{**Slope Area (m\({}^{2}\))**} \\ \cline{2-10}  & **[0, 9]** & **[9, 18]** & **[18, 27]** & **[27, 36]** & **[36, 45]** & **[45, 54]** & **[54, 63]** & **[63, 72]** & **[72, 81]** & **[81, 90]** \\ \hline \#1 & 766.20 & 2040.60 & 3576.64 & 5306.76 & 5594.60 & 3037.92 & 1397.20 & 496.84 & 63.56 & 0.16 \\ \#2 & 8318.96 & 16,219.48 & 21,520.04 & 29,405.20 & 27,553.64 & 10,941.68 & 3694.44 & 1188.00 & 128.44 & 1.64 \\ \#3 & 241.44 & 823.56 & 1808.32 & 3464.92 & 4022.12 & 2085.04 & 967.00 & 417.32 & 64.48 & 0.48 \\ \#4 & 14,801.76 & 18,724.80 & 19,369.80 & 22,644.76 & 17,623.16 & 5722.96 & 1955.24 & 589.04 & 110.60 & 2.44 \\ \#5 & 5301.20 & 12,128.56 & 13,384.12 & 12,716.88 & 8688.72 & 3668.20 & 1232.80 & 227.28 & 9.64 & 0.00 \\ \#6 & 5070.80 & 10,404.60 & 15,183.20 & 25,327.96 & 26,420.76 & 9643.64 & 2920.72 & 846.08 & 85.20 & 0.16 \\ \#7 & 1524.80 & 5811.36 & 12,001.48 & 18,934.56 & 20,777.56 & 12,052.44 & 4780.00 & 1425.08 & 145.12 & 0.20 \\ \#8 & 5343.16 & 12,494.56 & 16,816.32 & 25,408.72 & 27,048.12 & 11,328.27 & 3591.36 & 1006.40 & 108.24 & 0.32 \\ \#9 & 496.60 & 2018.12 & 4197.24 & 7348.16 & 8356.28 & 4778.08 & 1843.92 & 491.08 & 49.84 & 0.12 \\ \#10 & 1819.28 & 4175.60 & 6489.92 & 10,638.80 & 12,789.32 & 6172.80 & 2263.68 & 748.44 & 121.04 & 2.40 \\ \hline \end{tabular}
\end{table} 
Table 7: Statistical results of the slope areas of independent ridges. Figure 14: (**a**) Results of the percentage accumulation of the inside and outside of the slope of the pit rim structure, and (**b**) results of the percentage area of independent ridges’ slope. kurtosis was \(-1.29\), and the skewness was determined as \(0.22\). The data distribution was significantly different from the normal distribution, the distribution pattern was positively skewed, and the slope aspect values in the right part were highly discrete. The pit rim structure was dominated by the aspects of the north, northeast, east, and northwest, and the east area accounted for the highest proportion of \(19.16\%\). The aspect changed significantly in the south, west, and southwest directions, and the west and southwest aspects accounted for the least. In particular, the aspect distribution inside and outside was significantly different. Thus, the aspect distribution was determined using the same method as the slope analysis (Table 8 and Figure 15a). The aspect distribution of the outside ridges was quantitatively analyzed (Table 9 and Figure 15b). The proportion of the southwest aspect inside was highest at \(18.77\%\), the outside northeast aspect proportion was highest at \(19.63\%\), and the two aspect distributions were opposite (Table 8). The inside was mainly distributed in the south, southwest, west, and northwest directions (Figure 15a), and the vegetation coverage was high. However, the distribution of the aspect outside was the opposite, and there was a significant difference in the distribution of solar thermal resources. Since the inside was mainly depression topography, the aspect of the plane was higher than the outside. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Location**} & \multicolumn{8}{c}{**Percentage of Aspect Area (\%)**} \\ \cline{2-10}  & **Plane** & **N** & **NE** & **E** & **SE** & **S** & **SW** & **W** & **NW** \\ \hline Inside & 0.00 * & 12.89 & 4.59 & 5.40 & 9.93 & 12.39 & 18.77 & 18.35 & 17.67 \\ Outside & 0.00 ** & 18.01 & 19.63 & 19.82 & 15.79 & 7.96 & 3.33 & 4.11 & 11.35 \\ \hline \multicolumn{10}{c}{* 0.00144, ** * * 0.000898.} \\ \end{tabular}
\end{table} 
Table 8: Statistical results of the proportions of the inside and outside aspect areas of the pit rim structure.