A Study On The Early Townsite Moat Of The Central Plains Region

City moat is the ditch that people excavate around the city with the purpose of defense. A large amount of city moats of early townsite has been found and verified in the central plains area, two of which are city moats in Yangshao period, nine are Longshan period, seven are Xia Dynasty and six are Shang Dynasty.The form of early townsite city moat in the central plains area is various, so it can be classified by the number, scale, relative location with city wal, structural shape, mode of construction or even the way of get through. The city moat has evolved through four stages: embryonic stage——Yangshao period, beginning stage——Longshan period, development stage——Xia Dynasty and transformation stage——Shang Dynasty.City moat is closely linked with the city origin. City originates the village around the moat. The moat is evolved into city moat gradually since city has been found, with the function of city moat.City moat and city wall are mutually supportive. In general, the city wall is built by the soil that dig out while building the city moat, and particularly, the defense equipment is city moat instead of city wall in some cities, however, for the most part, city wall and city moat is collaborative defense.City moat is closely relative with city construction. From protohistory to XiaShang-Zhou Period, city moat was the important equipment for flood discharge, and it was wide and deep so that the beast cannot get through. People built bridge through the city moat to get into and out of the city conveniently. City moat is connect with river channel in all directions, which is benefit to communication and transportation.City moat has been the important defense equipment second only to city wall in the defense culture, as the forefront of defense system.