Density of population depends upon topography and climatic conditions in the following ways
(i) Rugged topography and unfavourable climatic conditions are primarily responsible for sparse population, e.g. Arunachal Pradesh has very little population due to hilly areas.
(ii) Moderate to low rainfall, rocky terrain and less fertile soils have led to moderate population densities, e.g. Assam and Peninsular states. .
(iii) Flat plains, fertile soil and abundant rainfall support highest population densities, e.g. Northern Plains and Kerala.