The Archaeological Study on the Water Infrastructure and System of the Han Chang’an City
Zhang Jianfeng 张建锋
Chinese Academy of Social Sciences 中国社会科学院考古研究所
The Han Chang’an City was the capital city of the Western Han and Xin Dynasties. It was made up of both urban and rural districts. Throughout the 200 years of Chang’an’s occupation, water infrastructure of different forms and functions were erected in both urban and rural sections of the city. The systematic and diverse blueprint of the water system promoted the waterworks of and prevented floods in Chang’an, thus providing a solid bedrock for the survival and development of the city.
The water infrastructure at Chang’an can be divided into four different functional systems: water storage, sewage drainage, urban water landscaping and water transportation. The water storage system was comprised of artificial lakes, canals, reservoirs, and water wells. These facilities allowed for the drawing and diversion of water resources, thus providing a solution for water provision in Chang’an. The sewage drainage system was comprised of drainage canals, culverts, rainwater wells, cesspools, roadside ditches, city moats, and city walls. These facilities were located in single-unit buildings, courtyards, street districts, street sides, and the city exterior. They allowed for the collection, transportation and drainage of sewage in Chang’an. The urban water landscape system included reservoirs and landscape canals, which allowed for the beautification of the city. Occasionally the artificial lakes and canals also included properties for retaining and draining water. The water transportation system was comprised of watercourses, weirs, inlet channels, and water replenishment systems; this allowed for resource provision in Chang’an. The facilities of these systems were distributed in different sections of the urban and rural regions of Chang’an, thus guaranteeing water usage, drainage, and transportation in the entire city.
Atmospheric precipitation (rainwater and melted ice and snow) provided water to Chang’an. The precipitation was stored in rivers and lakes, and amassed as free flowing surface water; sometimes it would seep into the ground and be stored as groundwater. Both surface and groundwater provided immediate water sources for the population at Chang’an. Through the water storage system, surface water was transported to the water usage facilities and at the same time supplemented the groundwater storage system. On the other hand, water wells were the means through which the populations at Chang’an exploited groundwater for daily usage. The atmospheric precipitation and sewage surplus ran into the rivers through the drainage system; a small portion seeped into the ground and was stored as groundwater. To summarize, the water infrastructure in Han Chang’an City originated from atmospheric precipitation. Through its water storage and drainage systems, the water eventually united with rivers, lakes, and groundwater – creating a self-sufficient cycle of water resources in Chang’an.
By combining archaeological analysis of water infrastructure and water systems in Han Chang’an City with the study of natural landscape, social context, and local and regional chronological development, we can conduct synchronic comparisons with water systems in other regions of the world. It is only then that we can make conclusions about the regional and contemporary characteristics of the water infrastructure in Chang’an city, and the significance of its system in the history of water infrastructure development throughout the world. This will provide a basis for understanding patterns of water infrastructure in cities across time, and thus for ideas regarding the development of better water and hydraulic infrastructure in the future.
Zhang Jianfeng holds a bachelor’s degree and master’s degree in history from the School of History and Culture at Shandong University. Zhang obtained his doctoral degree in history from the Institute of Archaeology at the Chinese Academy of Social Sciences. Since 1997, he has been a research associate at the Institute of Archaeology at the Chinese Academy of Social Sciences. Zhang has been participating in the archaeological research of Han Chang’an City, mostly focusing on the archaeology of the Qin-Han period and the study of water management systems in ancient cities. Zhang’s most prominent work is The Archaeological Study on the Water Infrastructure and System of Han Chang’an City。