Meaning of 江山错落. 人间星火 Those two phrases are from this song on YouTube “礼仪之邦”.  I have high confidence that I understand the 人间星火.  But I am not quite sure about the 江山错落.
Here is Google’s version: The country is scattered. The world is sparkling.
If you need to explain both within the context of each other or within the context of the song itself that would be fine.
I don't think we can translate the two phrases word by word, as they are delivering an artistic message through singing.
The songwriter is trying to draw a vivid scenery in the listener's mind - at a star-covered evening standing on the hill looking down on the mountain surrounded village below, the scattered lights are glowing; alongside the village, the lazy water is slowly flowing in the river, so calm and peacefully beauty.
Wish this makes sense.