Dynamic changes and vulnerability analysis of carbon storage in the Hanjiang River Basin (Shaanxi Section) based on GIS and InVEST model

This study reveals the impact mechanism of land use change on carbon storage to provide scientific basis for ecological protection and "dual carbon" goals in the Hanjiang River Basin (Shaanxi section). Using land use data from 1980 to 2020, along with GIS spatial analysis and the InVEST model, we examined changes over space and time through a land transition matrix and the Potential Impact Index (PI). This approach allowed us to assess how shifts in land use affect carbon storage, as well as to gauge the vulnerability of carbon storage services. Results show land use intensity trended "fluctuating increase-decrease", with carbon storage showing "slight increase-sustained decrease-significant recovery". High carbon storage concentrated in Qinling-Daba Mountain forest-grass areas, while river valleys had lower storage due to cultivated land reclamation and urban expansion. Sink-increasing transitions ("grassland→forest", "cultivated→forest") added 70.74×10⁵ t and 34.02×10⁵ t, while sink-decreasing transitions ("forest→cultivated", "cultivated→construction") reduced storage by 21.15×10⁵ t and 23.99×10⁵ t. The negative PI index indicated long-term adverse impacts of land use on carbon storage.Land use change drives carbon storage dynamics, with policy interventions (e.g., farmland conversion) promoting recovery, though ecosystem carbon sink restoration lags. Future strategies should prioritize mountain ecological protection, optimize valley land use, control construction expansion, and integrate sustainable land use with carbon sink enhancement.