Human settlement and changes in the distribution of river systems in the Minqin Basin over the past 2000 years in Northwest China

摘要

Introduction: Arid area is an important base for human settlement, however, long and drastic human activities have altered the drainage patterns in the arid watersheds significantly, causing serious ecological consequences. This study, through a case study of the Minqin Basin, a microcosm of the artificial oases in the arid northwest China, used the multi-types of data to recover the spatial distribution of human settlement and drainage patterns during historical period and analyze the relationship between them over the past 2000 years.Outcomes: Before the Han Dynasty (121 BC), the utilization of water resources in the Minqin Basin was in the primitive stage and the drainage pattern maintained the natural state. From the Han (121 BC- 220) to the Wei-Jin Dynasties (220- 316), the utilization of water resources intensified unprecedentedly, but the natural shape of the river systems was still maintained. In the following 1,000 years or so, the drainage pattern was in the state of “following its own course” due to the small human population. In the Ming Dynasty (1368-1644), with the alteration of the main rivers, the water resource utilization increased obviously, but the human reclamations were mainly confined to the southern part of the basin. In the Qing Dynasty (1644-1911), the reclamation of the Liulin Lake area significantly changed the drainage patterns, resulted in the drastically northward expansion of human settlement. Since the foundation of the People’s Republic of China (PRC) in 1949, the artificial water system completely replaced the natural water system and intensified the ecological problems in the basin.Discussion: The changes over the past 2000 years show the drastic impacts of human activities on the alterations of the drainage patterns and related ecological problems in the arid Northwest China.Conclusion: Rehabilitation of such ecological impairments requires both ecological restoration projects and changes in human paradigm and behavior over multiple temporal and spatial scales.