A Preliminary Study On The Defense Function Of The Prehistoric City Trench In The Middle And Lower Reaches Of The Yellow River

The late Neolithic Age is an crucial period of the origin and development of Chinese civilization with the appearance of city as its typical feature. Prehistoric cities with rammed walls widely situate in middle and lower reaches of Yellow River known for strong rammed fortifications and deeply broad surrounding moats. The defense system assembled by fortifications and moats possessing double defense functions is the reflection of environmental factor and social factor. Therefore, the defense functions of prehistoric fortifications and moats are the entry point to study the relationship of prehistoric cities and Chinese civilization which have great significance to further understand the origin and development of Chinese civilization. Many prehistoric cities are found in the middle and lower reaches of Yellow River since 1930s and the academic circles have spared no efforts to do researches on this. Firstly, investigating from the perspective of social environment and natural environment, the academic circles have agreed on the military and flood defense. Secondly, the defense system combined by fortifications and moats has reached the double functions to defend the cities.However, the researches on the functions of fortifications and moats are not enough which embody on three aspects. The first one is about the standards of their functions, and only a few scholars propose that fortifications and moats have an effect on determining the defense functions of prehistoric cities. The second one is that almost nobody does researches on either fortifications or moats, but treats these two aspects as a whole. The third one is related to the relationship of regional differences and environmental conditions which the researches involved in the defense functions of prehistoric cities in the middle and lower reaches of Yellow River are not that deep.This thesis mainly studies the defense functions of fortifications and moats, and the regional differences about internal defense functions in the middle and lower reaches of Yellow River.Fortifications and moats are important in developing the defense functions of prehistoric cities, and they are an integrated whole as well as react independently on each side. Firstly, as for the standards of defense functions, they are defined whether it reaches the purpose of defense functions or not including structural forms and quantitative values. Secondly, in terms of military, engineering, military strategy and battles, combined the archaeological excavations found in the middle and lower reaches of Yellow River, investigating location, layout, structure, scale and attached facility, it comes to conclude the standards of fortifications and moats listed as followings: ① City located in the high and spacious place; ② High walls with steep slopes around; ③ Straight walls with ample platforms on the top; ④ Broad and deep moats; ⑤ Military defense facilities in city gates and walls. Thirdly, in terms of hydraulics, hydromechanics, and structural mechanics, exampled by literature records of hydraulic history and water battles of military history in ancient China, combined the archaeological excavations, investigating location, layout, structure, scale and attached facility, it comes to conclude the standards of fortifications and moats listed as followings:①CCity located in the high and spacious place; ②Archy walls with steep slopes around; ③Moats or natural lower spots; ④flood and drainage facilities within the moats. Finally, it summarizes and compares the standards of military defense and flood defense through studying the forty-two ancient cities in the middle and lower reaches of Yellow River, to inspect the defense functions one by one.In regard to the military defense, consulting fortifications and moats referred to the defense functions of military and engineering which are protected by fortifications and moats in the military history and strategies, it is known that the prehistoric cities are mainly defended by fortifications and assisted by moats, and occupies a great importance. In regard to the flood defense, consulting formal requirements in hydraulics, hydromechanics, and structural mechanics which consider the engineering methods in hydraulic history and water battles of military history, it is also known that the prehistoric cities are mainly defended by fortifications and assisted by moats, and occupies a great importance.There are common points, but differences in prehistoric cities about time, layout, structure, scale, connotation and so on between Central Plain region and Haidai region. From the previous standards and structural forms of prehistoric cities in both Central Plain region and Haidai region, it obtains the differences in these two places that the functions of prehistoric cities in Central Plain region consider military defense firstly and follow by flood defense while those in Haidai region consider flood defense firstly and follow by military defense. According to social environment and natural environment at that time, with prehistoric cities of their using time, layout, structure, architectural style, attached facility and so forth, these differences are drived by the factor of constructing fortifications. The prehistoric cities in Central Plain region possess military property and are the product of conflicts caused by social turbulence and cultural community while those in Haidai region have flood property to prevent people from hurting by floods.