Spatio-temporal change of landscape ecological quality and influencing factors based on four-quadrant model in overlapped area of cropland and coal production

Abstract: The overlapped area of cropland and coal production is an important region in the national security strategy system, which is related to the country's food security, energy security and ecological security. In this area, coal mining continuously changes the function and process of the original agricultural landscape ecosystem by influencing the landscape pattern of the area, and the analysis of the landscape ecological quality and its influencing factors has important theoretical significance and practical value for the ecological governance of the mining area. The overlapped area of cropland and coal production of Zhaogu coal mine in Huixian city of Henan province was taken as the research area, and the administrative village was the evaluation unit. This study comprehensively evaluated the landscape ecological quality of the research area by using the four-quadrant model. The results showed that: 1) under the influence of coal mining activities and land ecological regulation, the cultivated land area of the study area generally presented a trend of decreasing first and then increasing from 2008 to 2016, and the cultivated land was mainly transferred to construction land and water area. The construction land increased first and then decreased, and the construction land was mainly transferred to water area and cultivated land. 2) The landscape stability index of the study area first decreased and then increased, while the landscape disturbance index first increased and then decreased. 3) The landscape ecological quality of the study area presented the change characteristics of "good - bad - good" on the time scale. In 2008, in the initial stage of mine construction and mining, the landscape ecological quality of the study area was better as a whole. In 2011, the degree of landscape disturbance increased and the degree of stability decreased with the increase of mining activities, resulting in the decline of regional landscape ecological quality. After 2014, large-scale land ecological reclamation increased the land utilization rate of the research area. The large area of water area formed by mining subsidence improved the regional landscape structure and the stability of the landscape system. Therefore, the landscape ecological quality of the research area showed a trend of improvement. 4) On the spatial scale, under the influence of mining activities and subsequent land reclamation, the landscape ecological quality of the villages near the mining area showed a change trend of first getting worse and then getting better, while the villages far away from the mining area showed a trend of slight deterioration. In general, the number and area of the villages with excellent quality increased in 2016, while the number and area of the villages with poor quality decreased compared with 2011. However, compared with 2008, the number and area of the villages with excellent quality were still smaller, while the number and area of the villages with poor quality were still larger in 2016, which indicated that although the landscape ecological quality of the research area had improved, it has not yet recovered to the level of landscape ecological quality before the disturbance.