Assessment of CO2 geological sequestration potential in the Northern Jiangsu-Southern yellow Sea Basin via AHP-CRITIC methodology

As a responsible major country, China is leading the world in carbon emissions while actively promoting carbon reduction and emission reduction efforts. CO₂ geological sequestration is one of the key direct emission reduction technologies. The North Jiangsu-South Yellow Sea Basin, a significant sedimentary basin in eastern China, holds substantial potential for CO₂ geological sequestration. The suitability assessment of CO₂ geological sequestration is the basis for the deployment of CO₂ sequestration projects, and the key is how to scientifically and effectively select the deployment sites. This study focuses on the Subei-South Yellow Sea Basin, constructing an index system consisting of 3 criterion levels and 14 indicator levels. The AHP-Critic combined method was used for indicator weighting, and a multi-level fuzzy comprehensive evaluation method was applied to assess the CO₂ geological sequestration suitability of 13 depression units in the basin. Haian and Qintong Depressions were identified as suitable regions for CO₂ geological sequestration in the North Jiangsu-South Yellow Sea Basin, with Baiju, Yancheng, and Gaoyou Depressions categorized as secondary suitable areas. The assessment results offer scientific support for site selection and engineering of CO₂ geological sequestration in the North Jiangsu-South Yellow Sea Basin.