唐代蕭関新城の位置と長安西北部の唐代交通路に関する一試論

Corona 衛星写真の判読と現地調査による検討

抄録

The author checked the full routes traveled by monk Xuanzang 玄奘 between Ch'ang-an 長安 and India during the period from the end of the Sui 隋 dynasty to the early Tang 唐 dynasty.
Three routes from Lanzhou 蘭州 to Ch'ang-an, on the way return, are noted with special remarks as a highlight of this study on the monk's seventeen years journey to India. Although no final conclusion was made from my study, I indicate, however, one of them as a target to be seriously considered.
I found descriptions of the geographical location of the ancient town of Xiaoguan Xincheng 蕭関新城 in two old books, XIN TANG SHU『新唐書』and YUAN HE JUN XIA ZHI『元和郡縣志』by which three routes could possibly be verified.
These routes are important Tang dynasty traffic routes from Ch'ang-an to Lanzhou via Guyuan 固原 that follow the Qingshui River 清水河 northward along the eastern side of the Liuban Mountain Range 六盤山脈. As for the location of Xiaoguan Xincheng fortified town, historians like Prof. Yan Gengwang 嚴耕望 in his book, TANG DAI JIAO TONG TU KAO『唐代交通圖考』(RESEARCH ON TRANSPORTATION ROUTES OF THE TANG DYNASTY) specify the location to be at Liwangpu 李旺堡 at the northern part of Guyuan District in Ningxia Hui Autonomous Province 寧夏回族自治区.
Although he also used the aforementioned old book that state that Xiaoguan Xincheng is on the east side of the river, he declared Liwangpu to be the site of ancient Xiaoguan Xincheng despite the fact that, in actuality, Liwangpu is located on the western bank. Therefore, the author checked Corona Satellite Photographs in detail and found three other sites, located Guanqiaopu 関橋堡, both north (Honggucheng 紅古城) and south (Caochenggucheng 草城古城) of Gao'ai Township 高崖郷.
The relic site located some 20 kilometers north of Liwangpu in the area north Geo'ai is of a remarkable large scale with walledcity. And these are, as written in the two old books, on the eastern bank of the river, proving the information to be true. Having succeeded in reading the Corona Satellite Photographs, the author took an field investigation to the area in February 2004. When, by good luck, the area north of Gao'ai was being excavated for highway construction since December 2003.
At the site known as Honggucheng, they found ruins from three periods from the Han 漢 dynasty, the Tang and the Sung 宋. Based on the above mentioned, the author finally considered that this Honggucheng site is the Xiaoguan Xincheng fortified town of Tang, and dismissed Liwangpu.
Fragments dating from the Tang dynasty found in various ruins in the area, told the author that the area had been a very important place for traffic in Tang times. Information produced from research of Corona Satellite Photographs and on the field investigation of the site, pushed this study forward and shall be carried on by similar attempts in the future.