2. The Yellow Spring, which originated from Yang Junsong's Tian Yu Classic, a famous geomantic master in the Tang Dynasty, is an important theoretical basis of Yang Gong's Trinity Geomantic Method, and has been widely used in the practical operation of geomantic omen.
3. Yellow spring water is formed by the application of three-in-one water method, which consists of twelve aspects: longevity, bathing, crown belt, temporary official, emperor flourishing, decline, illness, death, tomb, extinction, fetus and nourishment.