From what angle does the first section of the poem Song of the Yangtze River describe the Yangtze River?

The first section of this poem mainly describes the Yangtze River from the perspective of geographical characteristics, praising the Yangtze River for running thousands of miles and nourishing the spirit on both sides of the strait. This section focuses on realism; The second section mainly describes the Yangtze River from the perspective of time and space, giving it symbolic meaning, always full of youthful vitality and always moving forward. This section is longer than the lyrics.