关键词: 湿润区, 红层软岩, 红层荒漠, 荒漠化, 南雄盆地

Abstract:

The development of domestic and foreign concepts, and previous research of desertification are reviewed in this paper. We conclude that extreme land degradation in sub-humid and humid regions should be classified as desertification. Due to the lithology of the soft redbed rocks, along with excessive resource exploitation by humans and the humid climate, a special kind of desertification occurred in redbed regions in Southern China. As preliminary research concerning redbed desertification, we put forward the concepts of redbed deserts and redbed desertification. We also elaborate on features of desertification developing in redbed regions, such as landform features, ecological features, and soil features. Then, utilizing Nanxiong Basin as a case study, the spatial patterns of redbed desertification and the patterns of desertification at the basin scale are analyzed. The process of redbed desertification begins as spotty uncovering, and then develops into patches. Redbed desertification has mostly occurred on hills formed of soft rock in the central part of the basin. Based on the field work, the mechanism of redbed desertification is discussed from the aspects of lithological features, natural impacts, and human activities. The triggers of redbed badland desertification are complex, but are mainly impacted by activities such as severe reclamation, forest fires, tree planting disturbances, dry-land degradation, acquirement of topsoil, and so on. Once red beds are exposed, the extension of the desert region can be caused by both nature and human activities.

Key words: humid region, redbed soft rock, redbed desert, desertification, Nanxiong Basin