1st: The first line talks about the “aerial borders”, or the view from high up of the borders of a city. This is talking about people running from a place. The next line depicts the speed they fled, there is a sense of urgency. The ‘flowery” confusion refers to the pattern that every one fled. They search for deliverance while planes fly over head, as the people happily bomb.
2nd: they go through this forest, it is very mysterious, and suddenly as if by some chance troops came and are sneaking through the dark forest. This could also be referencing the stealth of the men also trying to sneak out of the city and through the forest. half walking in the shadows refers to the way the light was in the woods.
3rd:the sensual river is referring the the men’s desire to get in. the water was inviting to them. It can also refer to the current of the river. slow and inviting. they meet ends of the heat and relieve the heat. The peace they seek is a is across the borders from which they flee. Refuge is what they seek.