Coordination of economic development and ecological conservation during spatiotemporal evolution of land use/cover in eco-fragile areas

Abstract

Coordination of economic development and ecological conservation in land use/cover (LULC) remains a great challenge, particularly in eco-fragile areas. A holistic understanding of LULC change is a premise for coordinating the conflict. In this study, we elucidated the spatiotemporal evolution of LULC in China′s typical eco-fragile area-the Three Gorges Reservoir area during different periods of Gezhou Dam-Three Gorges Dam (GZD-TGD) construction and impoundment (1982–2020), and predicted LULC in 2030 with the patch-generating land-use simulation (PLUS) model. In 1982–2020, the LULC changes mainly included cropland loss, forestland restoration, urban development and water expansion, among which cropland decreased by 4688 km2, while forestland, built-up land and water increased by 3273, 1002 and 272 km2, respectively. For most LULC types, the most significant change occurred in 1995–2005, whereas the built-up land increased exponentially from 0.41% to 5.06% during the entire study period, which was mainly derived from cropland. Under a natural development scenario, cropland would drop continuously by 1094 km2 till 2030. In addition, there were significant interconversions between various land types before GZD-TGD impoundment of 175 m, particularly vegetation, while only built-up land increased dramatically by occupying 2.66% of cropland thereafter. Contributions of various driving factors to LULC changes varied across different periods due to the direct/indirect effects of GZD-TGD construction and impoundment. Most changes in LULC were elevation-sensitive, and supplemented by other factors. Furthermore, the expansion of various LULC types tended to occur more often in areas with low elevations and gentle slopes. The results may assist decision-makers in formulating more reasonable policies to alleviate the conflicts between land utilization and ecological protection, and facilitate the realization of China′s ecological civilization construction goals.