From urban to nature: A continuous landscape gradient mapping framework in Southwest China

Urbanization and rural development drive landscape transformation, which, combined with natural factors, forms a complete landscape gradient, namely the urban-suburban-rural-natural (USRN) gradient. Understanding the spatio-temporal evolution of gradient landscapes is crucial for managers to formulate major scientific policies to promote sustainable development. To this end, we constructed a new integrated framework that combines impervious surface and cultivated land data. An identification matrix was determined using empirical thresholds, and the identification results were optimized through the MSPA method. Taking Southwest China as an example, we analyzed the spatio-temporal evolution of the gradient landscape in this region over the past 35 years. The results show that: 1) Compared with other datasets, the average R² of the USRN dataset is higher than 0.8, which has unique advantages in terms of spatial integrity. 2) The inflection points of the gradient landscape change in Southwest China occurred in 2006. The urbanization process in the Sichuan Basin started earlier, and the Yunnan-Guizhou Plateau is the area where various landscape types have changed most significantly. 3) The transformation intensity is the highest in rural areas, and the transformation speed is the fastest in suburban areas, while the natural areas are opposite to rural areas. The results of this study enhance our understanding of the spatio-temporal evolution characteristics of continuous landscapes, as well as the gradient angle and direction. It helps us more carefully evaluate the sustainable development goals and provides a continuous and systematic understanding of landscape dynamics.