Drought promoted the disappearance of civilizations along the ancient Silk Road

摘要

Understanding the reasons of the disappearance of oasis civilizations along the ancient Silk Road will provide useful references for human's adaptation to environmental changes in the extreme arid regions in the nowadays and future. Although some studies have associated the demise of complex societies with deteriorating climate in the world, the demise of the civilizations along the ancient Silk Road has remained unresolved. Here, this paper used the nearly 2000 years of climate characteristics revealed by Guliya ice cores, combined with the reconstruction of temperature from tree rings located in the west Kunlun Mountains around the Tarim Basin to examine the climate variations in the Northwestern China in the historical periods. Then this paper compared the demise time of the ancient oases civilizations along the ancient Silk Road from the relevant annals of states and counties. The results showed that climate change may be responsible for the rise and demise of past oasis civilizations in the ancient Silk Road. The periods of fourth to fifth centuries and the seventh to eighth centuries were characterized by long-term drought accompanied by cold climate; five ancient oases and seven ancient oases were demised, respectively, during these periods. Cold-dry climate could cause a deficiency in water resources for irrigation; thus, agricultural production fell and the society was destabilized. Recently, creation of a new "Silk Road economic belt" is realized. Modern oases will face more serious threat under the climate change. The region's irrigation area increased 67.2 % over the past 30 years. The agricultural sector consumes 93 % of regional renewable water resources. Once the drought occurred, many modern oases-like their ancient counterparts-may well trigger more civil uprising and violent conflict in the already water-stressed regions.