Factors which affect the density of population are:Climatic conditions: The regions with moderate and favourable climate are densely populated. For example, the state of Kerela which has a moderate climate with high rainfall is densely populated than the extreme north western parts (Thar Desert) of the country which experiences extreme climate and scanty rainfall.Nature of land: Flat fertile lands are densely populated than uneven and rugged land. For example, the Northern Indian plains are densely populated as the land is even and flat. It is easier to develop transport facilities, construct buildings and houses on the leveled land. In India, Arunanchal Pradesh has the least density of population due to mountains, hills and extremely rugged terrains.Fertile soil: Since agriculture is the main economic activity, higher concentration of people are found in the regions of fertile soil like northern Indian plains in the north and Kerala in south.