劉安
From the 1st century AD onwards, official Chinese historical texts contained a geographical section (Diliji 地理纪), which was often an enormous compilation of changes in place-names and local administrative divisions controlled by the ruling dynasty, descriptions of mountain ranges, river systems, taxable products, etc. From the 5th century BC "Shu Jing" forward, Chinese geographical writing provided more concrete information and less legendary element. This example can be seen in the 4th chapter of the "Huainanzi" (Book of the Master of Huainan), compiled under the editorship of Prince Liu An in 139 BC during the Han Dynasty (202 BC–202 AD). The chapter gave general descriptions of topography in a systematic fashion, given visual aids by the use of maps (di tu) due to the efforts of Liu An and his associate Zuo Wu. In Chang Chu's "Hua Yang Guo Chi" ("Historical Geography of Szechuan") of 347, not only rivers, trade routes, and various tribes were described, but it also wrote of a 'Ba June Tu Jing' ('Map of Szechuan'), which had been made much earlier in 150.