English to Spanish Tech/Engineering Transport / Transportation / Shipping

Hello!

The term appears in the maintenance description for slab tracks, the text specifically talks about Measurement and Observation runs of the tracks. I don't really understand the meaning of settlement in this sentence. Does anyone know how to translate it?

Context:

In relationship with the slab track the evaluation of the measurement and observation runs allows especially the check of the vertical and horizontal position and thereby the identification of the settlement areas.

Thank you very much in advance!