Explain the factors responsible for the very high population density in the (a) North-East of USA (b) Indus and Ganges deltas.

Factors responsible for very high population density

(a) North-East of the USA (the Manufacturing/Boston-Washington belt)

1. Early settlement and industrialisation: this was the first area settled by Europeans and the cradle of American manufacturing, so towns and industries grew early.
2. Rich resources and power: nearby coalfields (Appalachians), iron ore from the Great Lakes and abundant capital fed heavy industry, attracting workers.
3. Excellent transport and trade: fine natural harbours (New York, Boston), navigable rivers, the Great Lakes-St Lawrence route and dense rail/road networks made it a great commercial and port region.
4. Concentration of commerce, finance and services in great cities such as New York, together with continuing in-migration, keeps densities high; the cool temperate climate is also favourable to work.

(b) The Indus and Ganges deltas/plains

1. Fertile alluvial soils deposited by the rivers, giving high crop yields that can feed a dense population.
2. Ample water for irrigation from the rivers plus the monsoon rains, allowing intensive, often double-cropped, farming of rice, wheat and jute.
3. Flat, easily-cultivated and easily-settled lowland that supports intensive wet-rice agriculture, which itself demands much labour.
4. Long history of settlement and agrarian civilisation, with many old towns and cities and a favourable warm climate, so numbers have built up over centuries.