Yi Tu of Haihua was written by Jia Dan, a geographer in Tang Dynasty. This map was compiled according to Pei Xiu's Six Maps in Jin Dynasty, and the scale of the map is "one inch folds a hundred miles". Pei, also known as Liu, is the earliest cartographic theorist in China. This theory systematically expounds the scale, orientation, distance and other elements of the map for the first time, which has a far-reaching impact on the map drawing of later generations.
At the age of 55, Jia Dan organized painters to draw maps. The whole map took 17 years to complete. The map is painted in two colors, and the place names are marked in different colors. The China part of the notes is based on Gong Yu, and the foreign part is based on Ban Gu's Han Shu. This is a big map of China and its neighboring areas.
Introduction to the Features of Flowers in the Sea
First, it attaches importance to the foreign part. Although it is interview materials, it pays attention to reality and corrects many mistakes. The time span is from the Xia Dynasty to the Tang Dynasty in the legendary era, and the geographical scope is not limited to the mainland of the Tang Dynasty, including all geographical areas known to the author except the Tang Dynasty.
Second, it pays attention to the textual research of historical geography, and the ancient and modern place names are colored differently, creating a precedent for the evolution map of China. The width of Haihua Yi Tu is about 10 abbot, which is 10 times larger than Pei Xiu's Topographic Abbot Map, which shows the vastness of the project and the scale of drawing in the Tang Dynasty. Textual research and explanatory text related to the map will be used as an annex to the map, and another special volume will be written.
Thirdly, the identification method of "modern Zhu" is established, which not only adheres to the principle of comparing ancient and modern, but also solves the contradiction between historical and geographical factors and modern factors.