基于优化模拟的长株潭3+5城市群碳储量时空演变与预测

土地利用/覆被变化是导致地区生态系统碳储量变化的重要原因，探析土地利用与碳储量的时空演变规律，对区域国土空间规划与生态管理、实现“双碳”战略目标具有重要意义。通过构建GeoDetector-PLUS-InVEST模型，基于多源数据分析长株潭3+5城市群2000—2020年土地利用及碳储量时空演变特征，预测2030年不同情景下的土地利用和碳储量变化，并通过空间自相关模型分析碳储量空间分布规律。结果表明：1）经过优化模拟的模型Kappa系数、FoM系数、总体精度结果比未优化模拟的结果分别高出0.81%、1.00%、0.67%；2）2000—2020年，研究区土地利用变化表现为耕地、林地、草地和水域面积减少，建设用地和未利用地面积增加；3）2000年、2010年、2020年3期碳储量分别为31.262 4×10⁸、31.218 1×10⁸和31.089 1×10⁸ t，期间碳储量共减少17.328 7×10⁶ t；4）相比2020年，2030年自然发展情景下碳储量减少12.1483×10⁶ t，城镇发展情景下碳储量减少11.746 7×10⁶ t，生态保护情景下碳储量增加14.754 0×10⁶ t，3种情景下的碳储量空间分布较为相似，具有较显著的空间集聚特征，且与土地利用情况高度相关。研究结果可为长株潭3+5城市群土地空间规划和“双碳”政策的制定提供决策参考。

Spatio-temporal evolution and prediction of carbon storage in Chang-Zhu-Tan 3+5 urban agglomeration based on optimization simulation

Land use or cover change (LUCC) is an important factor leading to the change of carbon storage in regional ecosystems. Exploring the spatio-temporal evolution law of land use and carbon storage is of great significance to regional land spatial planning and ecological management, as well as to the realization of the strategic goal of "dual carbon". The GeoDetector-PLUS-InVEST model was built to analyze the spatio-temporal evolution characteristics of land use and carbon storage of Chang-Zhu-Tan 3+5 urban agglomeration from 2000 to 2020 based on multi-source data, to predict the changes of land use and carbon storage under different scenarios in 2030, and to analyze the spatial distribution regularity of carbon storage through the spatial autocorrelation model. The results showed that: 1) Kappa coefficient, FoM coefficient and overall accuracy of the optimized simulation model were 0.81%, 1.00% and 0.67%, respectively, higher than those of the non-optimized simulation. 2) From 2000 to 2020, the land use changes in the study areas showed that the areas of cultivated land, forest land, grassland and water decreased, and the areas of construction land and unused land increased. 3) The carbon storage of the three phases in 2000, 2010 and 2020 were 31.262 4×108、31.218 1×108 and 31.089 1×108 t, respectively, during which the carbon storage decreased by 17.328 7×106 t. 4) Compared with 2020, carbon storage under the natural development scenario in 2030 would decrease by 12.148 3×106 t, carbon storage decrease by 11.746 7 ×106 t under the urban development scenario, carbon storage increase by 14.754 0×106 t under the ecological protection scenario. The spatial distribution of carbon storage under the three different scenarios was relatively similar, with the remarkable characteristic of spatial agglomeration, and it was closely related to land use. The research results could provide decision-making reference for the land space planning and formulation of "dual carbon" policy within Chang-Zhu-Tan 3+5 urban agglomeration.