Spatiotemporal patterns of land-use change in the Taihang Mountain (1990−2020)

The Taihang Mountain is an important ecological security barrier of the North China Plain and the Circum-Bohai Sea Economic Zone, which has a unique natural environment and humanistic historical background. The study of landscape patterns in mountainous areas is not only beneficial to the development of mountain ecology science but is also important for guiding sustainable economic and social development and eco-environment protection. In this study, the temporal and spatial variation in land use types in the Taihang Mountain were studied based on remote sensing data from Landsat 30 m TM (in 1990, 2000, 2010, and 2020). In addition, combined with the gravity center model, a comparative analysis of the variation trend of land use patterns in the Taihang Mountain was identified. The results showed that: 1) cultivated land, forest land, and grass land were the principal land use types in the Taihang Mountain from 1990 to 2020, while other land use types were embedded as plaques. 2) Over the past 30 years, the cultivated land area had been decreasing and mainly been converted to building land. The areas of forestland and grass land decreased gradually and were mainly converted into cultivated land. Additionally, the overall area of water decreased. The river ecological restoration project implemented in the Dasha River from 2010 to 2020 led to a large amount of unused land being transferred into water area, slowing down the degree of decline in the area of water. Moreover, the area of building land, mainly converted from arable land, had increased annually. The unused land area increased at first and then decreased, which was mainly reflected in the transformation of the water area. 3) Over 30 years, mainly influenced by the precipitation level, the unused land barycenter migrated 93.74 km northeastward. The barycenter of cultivated land fluctuated, migrating mainly northward, showing a west–east–west swing. This indicates that farmland reclamation intensity in the west of the Taihang Mountain hilly area was higher than that in the east, which was mainly found in Yuncheng and Jinzhong of Shanxi Province. The barycenter transfer direction of forest land and grass land was mainly southwest, over a relatively small distance. Mainly because of natural factors, the barycenter of the water area migrated southwest from 1990 to 2010, then suddenly shifted to the east between 2010 and 2020. The reason for this change was an increase in the water area in the east caused by the comprehensive Dashahe River control project. Thus, it was found that ecological restoration projects carried out by human beings had a significant influence on changes in landscape barycenters. In addition, the barycenter transfer direction of building land was mainly northeast and was affected by urban development, such as in Changping, Fangshan, and Yanqing of Beijing City. In short, based on the above research findings, the driving mechanism of landscape pattern variation in the Taihang Mountain area over 30 years (1990–2020) was further described.