Abstract:

Inland lakes are sensitive to climate change and human activities in arid and semiarid areas. In the past 300 years, the Mu Us Sandy Land, north China has intensified desertification, and many lakes have shrunk or disappeared during this period. Tonghalake Lake is a desert lake on the southern edge of the Mu Us Sandy Land, which gradually disappeared from the Qing Dynasty to the Republic of China. Not only its current location but also its evolution process and reasons for changing remain controversial. The historical changes of Tonghalake Lake have a certain significance for revealing the interactive relationship between human activities and the environment. This paper focuses on the location and evolution of Tonghalake Lake and aims to take it as an example to explore the research methods for studying the historical changes of desert lakes. We collected geographical records and ancient maps involving the Mu Us Sandy Land during the Ming Dynasty and the Republic of China, such as Illustration of Four Zhen in Shaanxi Province, Qing Dynasty National Choreography, Huangyu Quanlantu in Kangxi Reign, Shipaitu in Yongzheng Reign, Shisanpaitu in Qianlong Reign, and 1:100000 Topographic Map of Shaanxi Province of the Republic of China. The main achievements of this study focus on the following aspects. First, erstwhile studies believe that Tonghalak Lake is in the Chengchuan ancient area. Howevr, we proved that Tonghalake Lake is different from the lakes in the Chengchuan area by studying ancient maps. Second, this paper employs the GIS method to digitize the historical documents and ancient maps, combined with the DEM and remote sensing images to determine the accurate position of Tonghalake Lake. The results show that the lake is located on the northern lowland of Ningtiaoliang Town, Jingbian County, Shaanxi Province. Third, after obtaining the location of Tonghalake Lake, we can infer that its source river should be the Shiguaizigou, a tributary of the Red Willow River. Compared with the traditional historical names positioning method, this method has higher accuracy in spatial and temporal. Finally, Tonghalake Lake’s size tended to expand in the three periods of Kangxi, Yongzheng, and Qianlong, but it quickly disappeared in the late Qing Dynasty. During that time, the climate in this area was cold, and human activities intensified. The land was developed into farmland, and the population gradually increased, reaching 100000 in the 19th century. Combining historical climate records and human activities data, it can be drawn that the disappearance of Tonghalake Lake was caused by the cold climate in the little ice age, land reclamation, and population pressure. This study provides basic data and feasible multidisciplinary technical methods for the study of desert environmental change in the historical period and helps to solve the long-term controversial problems in academic areas.

Key words: Tonghalake Lake, Hongliu River, Mu Us Sandy Land, geographic information system (GIS)