Ecological Indicators (Dec 2023)
Spatial and temporal patterns and risk assessment of carbon source and sink balance of land use in watersheds of arid zones in China - a case study of Bosten Lake basin
Abstract
In recent years, Northwest China has experienced rapid land-use transformation and urbanization. Land-use carbon emissions associated with human activities are an important cause of climate change. However, the carbon sources and sinks associated with land-use change in arid zone watersheds need further study. This study focuses on Bosten Lake in Northwest China and employs a combination of top-down and bottom-up methods to assess the spatial and temporal evolution of carbon source and sink balance under land use changes and identify areas with high carbon emission risks. The key discoveries are as follows: (1) The land use category shows a pattern of “three decreases and three increases.” Grassland, unused land, and water area have decreased, while construction land, arable land, and forest land have increased. Cultivated land shows significant expansion, with an increase of 2375.71 km2. The overall distribution of land use intensities breaks through traditional boundaries, resulting in more dispersed reorganization of land use types. (2) Carbon emissions originating from land use category exhibit an upward trend, with a net increase of 1413.38 × 104 t. Construction land emerges as the primary carbon source, while arable land experiences the highest rate of carbon source migration. Grassland serves as the primary carbon sink migration area. Transformations and rapid expansions of arable land contribute significantly to changes in carbon balance. (3) Carbon emission risks are prominent in agricultural and pastoral areas as well as urban core regions, gradually decreasing in surrounding areas with a single-core staggered distribution pattern. The carbon source exceeds the carbon absorption, indicating a significant imbalance in carbon balance. These findings carry significant implications for the promotion of low-carbon and high-quality development in the Bosten Lake basin and the optimization of national territorial planning.
