汉帝国交通地理的“直单于庭”方向

秦汉交通地理语汇"直",言方向正对,路径捷便。在特定的语境中又往往指正南正北方向。汉帝国交通地理的"直单于庭"方向,既直接关系军事交通格局,也与经济交通形势有密切关系。这一方向,与起点于九原即五原的秦始皇直道大致对应。秦始皇直道"直"的意义,因此得到准确理解的条件。汉帝国北上"直单于庭"方向的经济交往的作用,在讨论丝绸之路史的学术主题中有值得重视的意义。《史记》说"单于之庭直代、云中",由"代"而"云中",体现西汉初期与西汉中期的历史变化。有学者注意到卫青、霍去病北击匈奴"出定襄""遇单于"的明确的历史记录,以为"定襄""直单于庭"。就"直单于庭"方向而言,空间位置居于五原郡与云中郡之间的现今内蒙古包头土默特右旗地方,可以说具有坐标性的意义。其交通史的作用,在后世依然长期发挥,因而形成有久远影响的历史记忆。

The Direction 'Zhi Chanyuting' in the Han Dynasty

The geographical word’Zhi’in the Qin and Han Dynasty means facing a place directly and going there conveniently. In special context, it usually refers to south or north. In the Han Dynasty, the direction’Zhi Chanyuting’has a close relationship with military traffic pattern as well as economic traffic situation. This direction approximately corresponds to the ’Zhi Dao’ which started at Jiuyuan county(also known as Wuyuan county in the Han Dynasty) in the Qin Dynasty. Accordingly, it provided a factor to correctly understand the meaning of ’Zhi’of ’Zhi Dao’in the Qin Dynasty. Han Empire sent messengers head north to Chanyuting, such economical communication should be attached great importance when studying the history of the Silk Road. It was documented in〈Shi Ji〉that’Chanyuting zhi Dai, Yunzhong’, which meant the location altered from Dai to Yunzhong. This reflected the historical change at initial and the middle of the Western Han Dynasty. It was recorded that general Wei Qing and Huo Qubing’went out of Ding Xiang’’meet Chanyu’when they went north to attack the Huns. Some scholars considered that’Ding Xiang Zhi Chanyuting’. As for the Direction’Zhi Chanyuting’, it was located between Wuyuan county and Yunzhong county(today’s Tumote right Qi in Baotou, Inner Mongolia) and has great geographical significance. It continued to play important role in transportation in the following dynasties and formed long-lasting historical memory.