What natural boundaries influenced Harappan settlements?

Harappan settlements were significantly influenced by natural boundaries. The Indus and its tributaries provided fertile plains for agriculture, while the Thar Desert to the east acted as a barrier, shaping trade and movement. The Himalayan and other mountain ranges to the north and west offered protection and determined trade routes. Coastal areas near the Arabian Sea facilitated maritime trade. These natural features not only supported agriculture and trade but also played a role in the development and sustainability of Harappan cities.

This question related to Chapter 6 Social Science Class 6th NCERT.
From the Chapter 6. The Beginnings of Indian Civilisation.
Give answer according to your understanding.