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Land-use change and the associated influences on the carbon metabolism system should not be overlooked in the context of rapid urbanization. By combing carbon emissions/sequestrations accounting and ecological network analysis, this paper quantitatively described the general situation and spatial distribution evolution of carbon metabolism in the Beijing-Tianjin-Hebei (BTH) urban agglomeration from 2015 to 2019, investigated carbon flows induced by land-use change, and revealed the ecological relationships between the components of the system. The spatial distribution of carbon emissions showed a trend of high in the southeast and low in the northwest, while carbon sequestrations were the opposite. At the early stage of regional coordinate development, the migration of enterprises with heavy energy consumption and emission and expansion of the transportation network has promoted the economic development in the surrounding area of Beijing, but also lead to the carbon emission transfer and the severe imbalance of carbon metabolism. Despite that a slight improvement can be found in the carbon metabolism system of Beijing and Tianjin, Hebei province still faces intensely competitive ecological relationships between industrial land and other land use, and has a relatively low mutualism index. It is suggested that integrated land use planning, strict cultivated land protection policies, and proper ecological compensation mechanism are the key measures to facilitate the sustainable development of the BTH urban agglomeration. • A temporal-spatial evolution of carbon metabolism in the BTH urban agglomeration is presented. • The impacts of land use change on urban carbon metabolism system are investigated. • Ecological relationships between land-use changes are explored based on the ENA method. • Industrial transfer and expanded transportation exacerbate carbon metabolism imbalance. [ABSTRACT FROM AUTHOR]

In the acceleration of industrialization and urbanization, brownfield is an important resource for land regeneration and restoration targeting to recover its ecosystem function. Landfills, as a type of brownfield distributed in the highly populated areas, occupy massive land resources. The ecological restoration of landfills becomes an engineering approach to achieve multiple effects of society, environment, and economy. This paper aims to monitor and assess the restoration microclimatic effects of landfills restoration in China with remote sensing data and techniques. We selected representative landfill restoration projects, including Nanhaizi Park in Beijing, Nanhu Park in Tangshan, and Tianziling Park in Hangzhou, as the study cases. Using the Landsat imagery, the scenes of the pre-restoration, mid-restoration, and post-restoration were retrieved, and the surface energy balance equation was applied to calculate normalized difference vegetation index (NDVI), land surface temperature (T s), and evapotranspiration (ET), representing vegetation conditions and hydro-heat microclimate conditions. The study areas are divided into four subzones and extracted the calculated values for statistics and comparison. We defined an indicator of restoration intensity (RI) using the different subzones to the outer contour distance radius and restoration phases to evaluate the spatial-temporal restoration degrees. The spatial pattern dynamics was displayed in the urbanization context in the cases of Beijing and Tangshan. We examined and quantified the relations between RI and the key indicators, NDVI, T s , and ET. The overall results revealed that with higher restoration intensity, NDVI and ET became higher, and T s became lower. It suggested that the ecological restoration on the landfills brought better vegetation, cooling, and humidification effects for the microclimatic environment. Our research has the implications for monitoring and assessing the climatic effects of ecological restoration in the brownfield regeneration in a macroscopic and ecosystem perspective. Unlabelled Image • With satellite dataset, we developed a way to monitor vegetation and microclimatic changes in the restored landfills. • The indicator to quantify the ecological restoration intensity was invented with spatial distance and restoration phase. • Overall, with higher restoration intensity, vegetation and evapotranspiration improved, and surface temperature declined. [ABSTRACT FROM AUTHOR]