Dual impacts of human activities on land cover and carbon storage in the Yellow River Delta (1986–2023)

Abstract

Global warming, driven by excessive CO₂ emissions from fossil fuel combustion, presents urgent challenges for carbon cycle management, necessitating both emission reductions and enhanced carbon sequestration. As vital yet dynamic components of the global carbon cycle, deltas play a crucial role in carbon storage. The Yellow River Delta (YRD), known for its high sediment accumulation and substantial carbon storage potential, exhibits significant variability due to intense human activities, highlighting the need for a deeper understanding of its carbon sequestration dynamics. This study investigates spatiotemporal changes in land use and their impacts on carbon storage in the YRD from 1986 to 2023, using satellite remote sensing, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, and spatial analysis. While the total delta area remained relatively stable, internal land-use shifts were substantial. Grassland and tidal flats declined sharply, from 1730.69 km² and 1077.05 km² in 1986 to 730.67 km² and 641.69 km² in 2023, respectively. Meanwhile, construction land and aquaculture reservoirs expanded by 689.39 km² and 726.01 km². These transformations caused a net loss of 14.14 Tg C in carbon storage between 1986 and 2015, followed by a partial recovery of 2.47 Tg C by 2023, primarily due to the conversion of cropland to grassland. Ecological restoration projects have been instrumental in reversing carbon losses and improving ecosystem health. This study emphasizes the importance of sustainable land management and targeted ecosystem restoration in mitigating carbon loss and enhancing the ecological resilience of the Yellow River Delta.