关键词: 毛乌素沙地, 萨拉乌苏河, 环境变化, 人类活动

Abstract: Based on comprehensive analysis of the stratigraphic age, ancient ruins distribution, pollen analysis nearby Sarah Wusu River and archaeological information, ancient literature about this river, combined with field investigation, the authors found that the geomorphology hydrologic situation, vegetation, desertification and human activities have changed a lot on both sides of Sarah Wusu River since the Tang Dynasty. These changes are the results of both downcutting and climate change of Sarah Wusu River. The deep valley of Sarah Wusu River began to form after mid and late Tang Dynasty, and there were few lakes with almost no human activities before that time. The downcutting of Sarah Wusu River formed wetlands environment on it’s both sides in the Song and Yuan Dynasties which was suitable for the lush pastoral economy, resulting in prosperity of human activities. After the Yuan Dynasty, the depth of the river was too deep, causing the deterioration of the hydrological conditions. Along with climate change and human activities, it led to decline of environment and human activities. It was also an important reason for the desertification event in late Ming Dynasty.

Key words: Mu Us Sands, Sarah Wusu River, environmental change, human activities