Spatiotemporal dynamic change analysis of carbon storage in desertification open⁃pit mine

To clarify the evolution law of carbon storage in mining area and its response mechanism to mining activities is an important means to promote low⁃carbon emission reduction and green high⁃quality development of mining area under the background of carbon peak and carbon neutral “double carbon” goal. Based on land use/ cover，the In⁃ VEST model was used to evaluate the change of carbon storage in the Hongshaquan Mining area of Xinjiang from 2007 to 2020，explore the impact of land use change on carbon sequestration function under mining disturbance，and establish the coupling coordination degree model of landscape index，coal mining acreage and carbon storage for explo⁃ ring the development coordination degree of three parameters above. The influence range of mining landscape is quan⁃ tified using the contribution rate of landscape ecological function. The results show that:1 From 2007 to 2020，the un⁃ used land in the Hongshaquan mining area continued to shrink at a rate of 1.95 km2 / a，and the industrial and mining land and transportation land continued to expand at a rate of 1.68 km2 / a and 0.16 km2 / a，respectively. The dynam⁃ ic degree of land use is the highest (79.86% and 46.25% respectively)，and the other land types have not changed significantly. 2 From 2007 to 2020，the carbon storage of the Hongshaquan Mining area showed a trend of continu⁃ ous decline at the rate of 6 550. 769 t / a， and the cumulative reduction of carbon sequestration was 8. 516 × 104 t. The change of carbon storage space was mainly weakened in the north，showing that the unused land with carbon den⁃ sity of 96.34 t / hm2 in the north was gradually invaded by the expanding industrial and mining land with carbon density of 53.48 t / hm2 . The main reason for the decline of carbon storage was the transfer of grassland and unused land to in⁃ dustrial and mining land. 3 On the landscape scale，the landscape fragmentation of the Hongshaquan mining area in⁃ creased (patch number NP，patch density PD and shape index LSI increased by 194，1.185 and 6.856，respectively， while the convergence AI decreased by 0.104)，and biodiversity SHDI and uniformity SHEI increased (0.445 and 0.236). On the patch scale，the landscape of industrial and mining land and transportation land tended to be clustered and orderly，while grassland and unused land tended to be fragmented and disordered. The coupling coordination de⁃ gree of landscape index，coal mining area and carbon storage is in a weakening trend as a whole，from 0.948 (high⁃ quality coordination) in 2007 to 0.602 (primary coordination) in 2020. 4 Within 15 km from the mining landscape of the Hongshaquan Mining area，the farther the distance，the higher the average carbon storage per unit area. The car⁃ bon storage sensitive area in the mining area can be divided into three levels:extremely sensitive area (0-7 km)，sen⁃ sitive area (7-15 km) and insensitive area (beyond 15 km). This study can quantitatively reflect the carbon seques⁃ tration function of the mining area and its coupling mechanism with landscape pattern and coal mining area，as well as the influence range of mining landscape. Also，it can provide ideas for the implementation of low⁃carbon and high⁃ quality development of the mining area，and promote the precise service of the mining area to achieve carbon peak and carbon neutral “dual carbon”goals.