Coupling spatial-temporal change and driving factors of carbon stock for Wuhan metropolitan area using PLUS-Invest-GeoDectetor model

Focusing on the spatio-temporal variations of metropolitan area carbon storage and its driving factors serves not only as a crucial approach to promoting high-quality and sustainable development under expanding of metropolitan development, but also significant component in achieving urban carbon neutrality. This study was coupled spatio temporal variation of Wuhan metropolitan area carbon storage basing on the natural development (Q1), ecological protection (Q2) and cultivated land protection (Q3) scenarios through PLUS-InVEST-GeoDectetor model and combined with land use and multi factor analysis to reveal the key driving factors. The results show that the Q2 and Q3 scenarios have a significant inhibitory effect on the expansion of construction land and fluctuation change of the carbon storage of metropolitan area, showing a slight negative growth (net decrease of 0.43 Tg) during 2000 to 2020 year, furthermore the carbon sink function has the risk of accelerated degradation in the future. The carbon storage in the ecosystem of the metropolitan area showed the characteristics of high in the northeast and low in the west, gradually evolved symmetrically to the high value area along the Yangtze River from 2000 to 2035 year. The carbon storage of metropolitan area in 2035 decreased by 3.94 Tg (Q1), 1.16 Tg (Q2) and 5.24 Tg (Q3) respectively compared with 2020 based on the coupling of three scenarios, and the Q2 scenario can effectively inhibit the loss of carbon storage. In addition, the expansion of construction land in the metropolitan area from 2000 to 2020 caused a significantly conversions of cultivated land and forest land types, and led to significantly loss of carbon storage. The order of importance of the factors driving the spatial differentiation of carbon storage in the metropolitan area is: land use > slope > elevation > NDVI, and there is a positive synergistic relationship between the factors.This study is conducive to promoting the optimization of urban land use pattern and the high-quality development of metropolitan areas, and promoting the realization of the concept of better city life.