劉安
From the time of 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 Jun Tu Jing' ('Map of Szechuan'), which had been made much earlier in 150. The "Shui Jing" ("Waterways Classic") was written anonymously in the 3rd century during the Three Kingdoms era (attributed often to Guo Pu), and gave a description of some 137 rivers found throughout China. In the 6th century, the book was expanded to forty times its original size by the geographers Li Daoyuan, given the new title of "Shui Jing Zhu" ("The Waterways Classic Commented").