Changes in carbon sink value based on RS and GIS in the Heidaigou opencast coal mine

The dynamic change in the carbon sink value of the Heidaigou opencast mining area in the Inner Mongolia Autonomous Region of China was analyzed by remote sensing and geographical information system to investigate the effect of land rehabilitation and ecological reconstruction in mining area on the biogeochemical cycle of carbon. The mining area's carbon sink volume and value from 1987 to 2010 were calculated according to carbon sink capacity differences across various vegetation and land use types. The results indicate the following conclu- sions. (1) The carbon sink volume and value decreased by 17 % over 23 years, from 7,217,104.59 t and $1,082.57 million to 5,990,016.2 t and $898.50 million, respectively. (2) Assuming a dump is rehabilitated with 20 % woodland and 80 % grassland, the carbon sink volume and value can increase to 6,593,952.5 t and $989.09 million, respectively. The value would increase by 10.08 % after land rehabili- tation. (3) Assuming that other industrial land is rehabili- tated with grassland after the dumps are completely rehabilitated, the carbon sink volume and value would increase to 6,742,684.36 t and $1011.40 million, respec- tively. The value would increase by 12.57 % after land rehabilitation. The results indicate that land rehabilitation and ecological reconstruction can increase mining area carbon sinks and produce ecological and economic benefits. This study provides a new perspective on land rehabilitation and ecological reconstruction.