As part of my immersion process I am studying Chinese lyrics of songs that I like. Many times I find Chinese phrases that I understand all of the words but none of the context. In this case 大河向东流哇 seems to describe a great river flows eastward. The final word threw me for a loop and so I wanted to ask whether how that word affects the overall sentence? What is the implied emphasis being added (if any) or am I misunderstanding the interpretation?
My local MacOSX dictionaries tell me that 哇 (wā) is
哇 (Simplified/Traditional) | wā | sound of child's crying 哇 wā 拟声模拟呕吐、哭等的声音。 哇的一声吐了出来 | 小孩子哇 哇地哭。 另见 wa。 哇 wa 助“啊（a）”受前一个字韵母u、ao、ou 的影响产生音变而采用的不同写法。 你让我找得好苦（kǔ）哇 | 这样多好（hǎo）哇 | 快走（zǒu）哇。 另见 wā。 wā 哇 Wow!; sound of child's crying; sound of vomiting 哇
BTW - This line is from the following song/artist:
演唱: 刘 欢