论渭桥与西汉长安城北向防御带的构建

Discussion on Wei Bridge and the Construction of the Northward Defense Belt of Chang’an City in Western Han Dynasty

西汉长安城整体处于渭河以南,随着关中城市群迅速向渭北扩展以及汉匈关系变化,其北向防御纵深不断增大。高祖、惠帝时以渭河护城;文帝时受匈奴入寇影响,将渭北地区众多陵邑及关中诸要地纳入京畿整体防御体系中;至景、武二帝时,朝廷改内史为三辅,新筑东西两渭桥,推行制度化改革,进而构建起更大规模的渭北防御带。在此过程中,渭桥不但密切了渭河南北县邑的交流,更使关中地区在西汉时期所经历的一系列工程、改革、事件钩稽贯串,完整清晰地呈现在今人面前。

The Chang’an city in Western Han Dynasty was located to the south of Wei River as a whole.With the rapid expansion of the Guanzhong urban agglomeration to the north of Wei River and changes in the relationship between Han and Hun,the depth of its northward defense continues to increase.Emperor Gaozu and Emperor Hui used Wei River as a moat.Emperor Wen,influenced by the invaders of the Huns,included many tombs in the north of Wei River area and important places in the Guanzhong area into the overall defense system of capital.At the time of Emperor Jing and Emperor Wu,the imperial court turned Neishi into Sanfu,built the East and West Wei Bridge,and implemented institutional reforms,constructing a larger-scale defense belt on the north side of Wei River.In this process,Wei Bridge not only strengthened the exchanges between the northern and southern counties of Wei River,but also connected a series of projects,reforms,and incidents that the Guanzhong area experienced during the Western Han Dynasty,fully and clearly presenting them to people at present.