Research Of Urban Defense Facilities At Middle And The Lower Reaches Of The Yangtze River From Spring And Autumn Period To Warring Stages Period

As a material carrier for the national population and the development of political,economic,cultural and military forces,the ancient city site is one of the important objects of archaeological research.This material carrier must be equipped with strong defense facilities,which can be used to cope with natural and man-made disaster,flood and invasion mainly,to protect the safety of the city.Urban defense facilities are different during different historical periods.The spring and autumn period and warring stages period as the transformation period of the ancient society,the construction of the urban defense facilities are placed in an particularly important position.There are geographical differences exist in the urban defense facilities.The urban defense facilities in the middle and the lower reaches of the Yangtze river are different from those in the north central plains.These differences are not only reflected in the construction methods of the urban defense facilities,but also in the type and structure design of the urban defense facilities.At the same time,these differences are not limited to reflect the strength and the weakness of urban defense facilities in south and north,but also the reflects of the military thoughts,war patterns and other aspects in the spring and autumn period and warring stages period.Meanwhile,the urban defense facilities cannot be treated as isolated,it is connected to the peripheral natural defense shield and other artificial defense facilities.These connections can promote or inhibit the overall defense system.From the spring and autumn period to the warring stages period,the urban defense facilities developed dynamically,which were promoted by the political situation,military thought,pattern of the war and the growth of the population.On the other hand,development of the urban defense facilities also reflect the changes of the aspects mentioned above.In addition,the layout,resource reserve and psychology aspects can also affect the overall defense system of the city.After all,these are just the tip of the iceberg of the research of the urban defense facilities.There is plenty of room for the research on this topic.