Ying Tung Fung is a post-doctoral fellow at the Hebrew University of Jerusalem since October 2021 and she has been working on satellite imagery and GIS analysis in The Wall Project. She received her DPhil in Archaeology at the University of Oxford. She is an archaeologist who specializes in Chinese archaeology, mainly in the late Neolithic and early Bronze Age, and is interested in topics related to cultural interaction, stone fortification, chronology, subsistence practices, urbanism and climate change. Her doctoral research considered the temporal and spatial development in demography and social economy in North Loess Plateau during the period 2800-1300 BC. Her current research focuses on the late Neolithic stone fortification in North Losses Plateau and the medieval wall system in northern China and Mongolia.
Mapping and Analyzing the Southern Line of the Medieval Wall System
Although the Medieval Wall System (so-called Liao-Jin Wall) in China and Mongolia was studied in the past, there are still gaps and misunderstandings in our knowledge of this system. We still do not completely understand its functions and organization, who built these walls and when were they built. Since the northern line has been studied in the past few years (Shelach-Lavi et al., 2020a; 2020b), our research has begun to focus on the southern line. Different from the northern line, the southern line is a more complex system as it consists of many branches and sub-branches; for this reason, this paper considers the simplest wall line of the northern branch of the southern line system. This branch begins from the Ni’erji dam at the border between Heilongjiang province and Inner Mongolia, extends for about 3,000 km (including gaps in between), and ends around Yumen Gate in Dunhuang city.
Besides carrying out a study on Chinese archaeological literature, satellite imagery analysis and spatial analysis for this wall line, we also carried out a field survey this summer to investigate a section of this wall (400–500 km), which is located inside the border of Mongolia (hereafter the eastern Mongolian Arch) and has not yet been formally acknowledged and thoroughly researched by scholars. In the following, a brief explanation of the identification and mapping process for structures, findings and challenges will be given. The major discoveries from the survey along the eastern Mongolian Arch will then be discussed, followed by a discussion of potential future tasks and analysis for the entire wall line.
Different sources of satellite images (ESRI, ACME, Bing, Google), soviet maps, archaeological survey reports (Heilongjiang, 1961; Kovalev, 2021; Zhao, 1993), and archaeological atlas (Guojia wenwuju, 2003) were used to search and locate the wall remains and associated forts. For the structures which are not visible today, we investigated declassified ‘Corona’ images taken as early as the 1960s. These images are especially useful for identifying structures covered by agricultural fields and sandy areas in China. Through georeferencing, we digitized and mapped the walls and forts on Google Maps and ArcGIS pro. The wall line we identified and mapped clearly belongs to the same branch, even though there are still gaps in the continuous line. At this stage, 213 forts were mapped along this wall. 115 sites are distributed at the east of this wall, of those we were able to correlate 36 to the information from the archaeological survey reports and atlas, and 27 were identified from ‘Corona’ images.
We have been facing challenges in cases where structures cannot be seen in any type of satellite image. We realized that there are many gaps along the wall and missing forts in some areas. This situation is common for Mongolia in which the quality of images is low and also in sandy areas or sand dunes. Visiting Mongolia and investigating the structures is therefore crucial for better understanding the archaeological context of these structures, and the nature of and reasons for these gaps. During the field survey along the eastern Mongolian Arch, we managed to investigate 4 wall sections, 16 forts and 2 unknown structures. We collected optically stimulated luminescence (OSL) dating samples from some locations and recorded the information of the size of structures, specific structures such as gates and corner towers of the forts, ditch of the wall, and artifacts collected from these structures. In addition, drone was used to document the structures and wall sections, and to identify features with low visibility.
One unusual rectangular shape fort (MA20) we identified on the satellite image is located far from the wall line. We investigated this site and found a large number of glazed tiles with decorations. This is distinctive from the other square-shaped forts in which a small number of mundane pot shards were found. The date and nature of this fort need to be clarified via more intensive exploration. We also identified stone structures in some of the forts, usually at the corners and the gate of the structure we identified. Another major discovery is that the gaps along the wall were 'real' gaps rather than caused by natural deterioration or modern development.
In the future, we plan to continue both laboratory and field work to identify the structures along the northern branch of the southern line as complete as possible. Next year we will excavate at one or two surveyed forts in the hope of uncovering more information on the structure of the wall and the associated forts as well as their functions and dates of construction and use. Synthetic-aperture radar (SAR) images will be ordered to identify structures under sandy areas and sand dunes. Once the information becomes more complete, the data collected from the survey can be considered together with that from the rest of the branch. GIS analysis can then be carried out to examine the possible functions and building environments of the eastern Mongolian Arch as well as the entire northern branch and sub-branches of the southern lines.
References
Guojia wenwuju国家文物局, 2003. Zhongguo wenwu dituji Neimengguzizhiqu fence中国文物地圖集 內蒙古自治區分冊. Xi’an西安: Xi’an ditu chubanshe西安地圖出版社.
Heilongjiangshang bowuguan黑龙江省博物馆, 1961. Jin dongbeilu jiehao bianbao diacha金東北路界壕边堡調查 Kaogu 考古, 5, pp.261-268.
Kolalev, Alexey A. & Erdenebaatar, Diimaajav, 2021. The northern border of the Tangut state, XiXia: According to the archaeological evidence and written sources. The Archaeological Journal of Kanazawa University, (80), pp.49-77.
Shelach-Lavi, G., Wachtel, I., Golan, D., Batzorig, O., Amartuvshin, C., Ellenblum, R. and Honeychurch, W., 2020a. Medieval long-wall construction on the Mongolian Steppe during the eleventh to thirteenth centuries AD. Antiquity, 94(375), pp.724-741.
Shelach-Lavi, G., Honeychurch, W. and Chunag, A., 2020. Does extra-large equal extra-ordinary? The ‘Wall of Chinggis Khan’from a multidimensional perspective. Humanities and Social Sciences Communications, 7(1), pp.1-10.
Zhao, yuming赵玉明, 1993. Lingdong jindai changcheng diaocha 岭东金代长城调查. Neimenggu shehuai kexue内蒙古社会科学, (1), pp.61-67.