## 3 Results
### Comprehensive Evaluation of Ecological Environmental Quality in Incleng City
The mean RCEI values of Qinshui County and Lingchuan County fluctuated between 0.6684 and 0.7958 and 0.6947 and 0.8083, respectively, showing high ecological quality. The mining distribution maps showed that these two counties and districts had fewer coal mines and relatively lower levels of urban construction, so their mean RCEI values reached good levels, especially for Lingchuan County, where the highest mean RCEI value reached the excellent level. This finding provides a valuable comparative perspective for exploring the ecological quality of resource cities and demonstrates the effective applicability of RCEI indicators in resource cities. This study examined the ecological trajectory of Jincheng City across a span of 32 years, tracing the spatial dynamics of ecological quality through eight pivotal years from 1990 to 2022, as depicted in Table 6 and Figure 8. In 1990, a substantial portion of the city, comprising approximately 6481.26 km\({}^{2}\) or 68.29% of its total area, was classified under poor and average ecological conditions. These regions were primarily located in the mining and exploitation zones central to Jincheng City. In stark contrast, areas of favorable ecological quality were confined to the peripheral mountainous forests and grasslands. The data from 1990 unequivocally indicate a prevalent state of ecological degradation across the majority of the cityscape. This study examined the ecological trajectory of Jincheng City over a period of 32 years, tracing the spatial dynamics of its ecological quality through eight key years from 1990 to 2022, as shown in Table 6 and Figure 8. Figure 8 clearly illustrates the flow of ecological change within the study area during these selected years. The right section of Figure 8 displays the total area of the study region, which was 9490 km\({}^{2}\) for the years 1990, 1996, 2002, 2006, 2008, 2013, 2018, and 2022. The left section categorizes the RCEI index into five classes: poor, fair, moderate, good, and excellent. Notably, the area classified as \"good\" was the largest among the five categories, marked as 22,934 km\({}^{2}\) in Figure 8, while the area \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Year** & **Form** & **Poor** & **Fair** & **Moderate** & **Good** & **Excellent** & **Total** \\ \hline
1990 & Area (km\({}^{2}\)) & 667.42 & 4126.9 & 2354.36 & 1772.38 & 568.94 & 9490 \\  & Pct. (\%) & 7.03 & 43.48 & 24.81 & 18.66 & 6.02 & 100 \\
1996 & Area (km\({}^{2}\)) & 297.98 & 2269.12 & 3440.82 & 2477.06 & 1005.02 & 9490 \\  & Pct. (\%) & 3.14 & 23.91 & 36.25 & 26.11 & 10.59 & 100 \\
2002 & Area (km\({}^{2}\)) & 595.35 & 3433.23 & 2367.28 & 2183.18 & 910.96 & 9490 \\  & Pct. (\%) & 6.27 & 36.17 & 24.94 & 23.01 & 9.61 & 100 \\  & Area (km\({}^{2}\)) & 195.09 & 2156.05 & 3063.2 & 2334.11 & 1741.55 & 9490 \\  & Pct. (\%) & 2.05 & 22.71 & 32.27 & 24.59 & 18.38 & 100 \\
2008 & Area (km\({}^{2}\)) & 312.61 & 1103.77 & 2210.31 & 3323.15 & 2540.86 & 9490 \\  & Pct. (\%) & 3.28 & 11.63 & 23.29 & 35.02 & 26.78 & 100 \\
2013 & Area (km\({}^{2}\)) & 422.19 & 1214.65 & 2986.5 & 3537.3 & 1329.36 & 9490 \\  & Pct. (\%) & 4.44 & 12.80 & 31.46 & 37.27 & 14.03 & 100 \\  & Area (km\({}^{2}\)) & 782.39 & 1606.02 & 3147.34 & 3239.36 & 714.29 & 9490 \\  & Pct. (\%) & 8.24 & 16.92 & 33.17 & 34.13 & 7.54 & 100 \\  & Area (km\({}^{2}\)) & 341.88 & 839.9 & 1767.02 & 4067.83 & 2473.37 & 9490 \\
2022 & Pct. (\%) & 3.60 & 8.85 & 18.61 & 42.86 & 26.08 & 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Proportions of areas graded on their ecological quality from 1990 to 2022.  
classified as \"poor\" was the smallest, at 3615 km\({}^{2}\). This indicates a positive trend in the spatial and temporal changes in the ecological quality of the study area. By 2008, the area of regions with good ecological quality exceeded that of those of moderate ecological quality for the first time, while the area of regions with poor and poorer ecological quality decreased annually.