## 3 Results
### Transition Frequency and Correlation Between Meteorological Drought and Ecological Drought  
So how much impact does the occurrence of meteorological drought events have on the occurrence, duration, and intensity of ecological drought events? We need to specifically study the transition frequency and correlation between them. The frequency and correlation of the two data were calculated pixelwise, and the results are shown in Figure 15. The figure on the left illustrates the frequency of transitions from meteorological drought events to ecological drought events, with certain regions lacking specific values, signifying the absence of direct or indirect transition in those areas. On the whole, the average frequency of meteorological drought to ecological drought in the study area was about 55%, with a moderate transition frequency. The figure illustrates distinct regions, with a higher overall value in the north, suggesting that meteorological drought in these areas frequently transitions to ecological drought, thereby indicating the significant role of meteorological drought in the emergence of ecological drought. The transition frequency in the southern region was predominantly below 40%, signifying a lower transition frequency from meteorological drought to ecological drought in these areas. Consequently, the influence of meteorological drought on the emergence of ecological droughs was less pronounced than in the northern region, with other significant factors also affecting the occurrence of ecological drought. The figure on the right is the correlation between meteorological drought and ecological drought values in a pixelwise manner. The results showed a general positive correlation in the study area, with some scattered regions having negative correlations. Comparing the left and the right figures shows that although the region's short-term value is below the drought threshold, it does not necessarily indicate that persistent drought events will occur. There are some blank areas in the diagram that show no transitive relationships and correlations. Combined with Figure 6, it can be seen that the frequency and duration of meteorological drought in these regions are almost 0, indicating a low likelihood of meteorological drought in these regions, favorable ecological conditions, and a low probability of ecological drought. Outliers are removed prior to computing the correlation. Initially, let us analyze the relationships inside the stable zones, as presented in Table 3. The correlation of drought frequency, duration, and intensity of cultivated land was basically the same as that of grassland with medium and low coverage. The correlation of drought frequencies exceeded 0.7, signifying a considerable likelihood of annual drought occurrence. The association between drought durations was the most significant, suggesting that a long period of meteorological drought substantially influences the duration of ecological drought. The connection between drought intensities is weak, suggesting that severe meteorological  
Figure 15: Frequency and correlation between meteorological and ecological droughs in the Shen-dong mining area. drought does not inherently result in severe ecological drought. The frequency, duration, and intensity of drought in grasslands with varying coverages diminished as coverage increased, suggesting a correlation between the incidence and transition of drought and the degree of vegetation coverage. grasslands with substantial vegetation cover can markedly diminish the occurrence, duration, and severity of drought by enhancing soil water retention, regulating evapotranspiration, improving ecosystem resilience, obstructing drought propagation, modulating local climate variations, increasing ecosystem diversity, and affecting drought thresholds. This clearly illustrates the significant role of vegetation coverage in the incidence and propagation of drought, while also offering a crucial scientific foundation for the management and conservation of grassland ecosystems.