Summary: In 2015, the subsurface drainage system was firstly discovered in the capital city Lin’an of the Southern Song Dynasty. Along with the discovery of the drainage system, east walls of the Lin’an city was also recovered, which renders rich information about

In 2015, the subsurface drainage system was firstly discovered in the capital city Lin’an of the Southern Song Dynasty. Along with the discovery of the drainage system, east walls of the Lin’an city was also recovered, which renders rich information about the history of the Hangzhou city.

Discovery of the drainage system for the first time

The drainage system is comprised of surface river courses and subsurface drainage. It was important to transport the water from the Xihu Lake into the city and disperse around the city as daily activities within the city heavily relied on the water. To understand the importance of this drainage system, the excavation was conducted during April to September 2015, aiming to reveal the subsurface drainage facilities.

There were discoveries of dwelling foundations, water wells, pounds, ditches and roads and so forth in the excavation. Among them, the ditch G1 with wooden drainage pipe structure connecting water wells J5 and J9 is impressive. The construction of the G1 had great significance, which matches the building techniques described in the construction textbook of the Song Dynasty.

According to the records in texts, the niezi well was located at this spot where the ditch G1, water wells J5 and J9 were found. These features might have been associated with the niezi well. It was the first discovery of this particular type of the feature, which provides tangible evidence of the water utilization in the Lin’an city during the Southern Song Dynasty. Although the general preservation of them is not ideal, the findings do contribute to our understanding of the development of the Lin’an city during the Southern Song Dynasty and on forth.

First Revealing the east wall of Lin’an city

During April and June 2015, the excavation was conducted on the east wall of Lin’an city. Comparing with previous ones, this excavation covered the largest area and yielded richest remains.

The east wall had its long axis aligned north-south with the remaining length of 36.3m. The main part of the east wall is 10.50m wide. The inner structure was filled by fine greyish-green sandy soil and it was covered by layers bricks on both sides with foundations at the bottom. The foundation in the east is 1.7m wide, 0.37m high while the one in the west is 1.75m wide and 0.45m high. The foundation was made by a layer of stamped sands mixed with small pebbles at the bottom and at the top covered by stone slabs of various sizes. The brick is generally 36cm wide, 18cm wide and 8cm high. There were revetments on both sides of the wall, the east side is approximately 6.25-12.3m wide, whereas the west side is about 0.2-6.3m wide. Both of them were made of stones and sands.

This part of wall is preserved in good condition, providing detail information for the reconstruction of the city plan.

Application of the remote-sensing technology in detecting the city wall of Lin’an city

The modern Hangzhou city was erected upon the palimpsests of ancient cities. Therefore it would be unrealistic to excavate the archaeological remains underneath it at the cost of disturbing its modern function. The application of remote-sensing technology partially solves this problem.

Excavating the east city wall of the Yuan Dynasty

During October and December 2015, remnants of ancient city walls were discovered and the excavation was conducted afterwards. This city wall was constructed during the late Yuan Dynasty and in consistent use till its abandon in the earlier 20th century.

Two trial trenches (T1 and T2) were excavated. Trench T1 was allocated in the east part of the excavation area and the city wall of Yuan dynasty was situated in the center of T1. The long axis of the city wall is aligned north-south. It was comprised of walls and bastions, with the remaining length of approximately 48 meters. The bastions were located in the north part of the trench, east to the main part of the city wall.

This excavation area occupied an important location, in the west to which lied the east wall of the South Song city. Underneath it, there was remnant of the water enclosure of the Five Dynasties while the east wall of the Hangzhou city in the Yuan Dynasty was in the east of it. This part of the wall has the best preservation among all the walls discovered so far which clearly displays the structure of the city wall. Together with the walls of the Lin’an city found on the Shangcangqiao Road, it renders rich information on the construction technology during the Song and Yuan Dynasties in addition to the history of the Hangzhou city.     (Translator: Dong Ningning)