The main reason why areas of South Asia with arid climates aren't densely populated is due to the lack of water resources. In arid regions, there is generally very little rainfall, and the ground is often dry and barren. Agricultural production can be severely limited because of a lack of irrigation systems and sufficient water resources, making it difficult for people to grow crops and raise livestock. As a result, arid areas tend to have relatively low population densities as people typically move to areas with better access to water resources.
