Scenario-based simulation of carbon storage in Chengdu using MCCA-InVEST: land use change, spatial patterns, and...

To achieve Chengdu's dual-carbon goals and support high-quality development, it is essential to analyze the impact mechanisms of land use patterns on carbon storage in Chengdu. This study aims to provide evidence-based land use planning strategies that synergistically balance ecological security and economic growth for the Chengdu-Chongqing Economic Circle's dual-carbon objectives.

This study uses the MCCA - InVEST model to simulate the impact of land use changes on carbon storage in Chengdu City from 2025 to 2035, setting up three scenarios: natural development (ND), ecological conservation (EC), and sustainable development (SD). The MCCA model is used to simulate land use dynamics by integrating 11 driving factors. The InVEST model is then used to assess changes in carbon storage, with a focus on the area evolution and carbon storage response mechanisms of cropland , forests, and impervious land.

Land use changes show that under the ND scenario, cropland decreases by an average of 0.82 million hectares per year, impervious land expand by 38.1%, and forest area increases by 20.8%. Under the EC scenario, the rate of cropland reduction slows, with forests growing at an average annual rate of 2.6%, and impervious land expanding by 28.1%. Under the SD scenario, which lies between the two, the reduction in cropland is 0.5 million hectares less than in the ND scenario, forests increase by 25.0%, and impervious land expand by 32.4%, achieving a balance between loss and gain. In terms of carbon storage, the ND scenario results in a net decrease of 9.6×10⁶ tons, the EC scenario results in a net increase of 13.2×10⁶ tons, and the SD scenario remains largely stable. In terms of spatial distribution, high carbon storage areas are concentrated in the Longquan Mountains and the western mountainous regions, with NDVI being the primary driving factor (q=0.7264).

The SD scenario can balance ecological conservation and economic development. It is recommended to enhance forest construction in the Longquan Mountains and the western mountainous regions, and to promote 'compact' expansion in the urban core area. The MCCA-InVEST coupling model provides an effective tool for evaluating carbon storage across multiple scenarios. This study offers a scientific basis for Chengdu City to achieve its 'dual carbon' goals and serves as a reference for other cities conducting carbon storage assessments and land use planning.