Ganges Basin (112,490 km²), West Bengal (71,485 km²), Haryana (34,341 km²), Himachal Pradesh (4,317 km²) , Delhi, Arunachal pradesh(1,484 km²), the whole of Bangladesh, Nepal and Bhutan. Several tributaries rise inside Tibet before flowing south through Nepal. The basin has a population of more than 500 million, making it the most populated river basin in the world. The basin comprises semi-arid valleys in the rain shadow north of the Himalaya, densely forested mountains south of the highest ranges, the scrubby Shiwalik foothills and the fertile Gangetic Plains. Central highlands south of the Gangetic Plain have plateaus, hills and mountains intersected by valleys
Nutrient cycling in the Columbia River Basin changes due to climate and land-use variability, but generally ranges from 120,000 to 260,000 cubic feet per second. Finally, the population of the Columbia River Basin within the United States is about 4.6 million people (per the 2000 census). The water cycle in the Columbia River is dependent on the relation between water flow and topography in the basin. Within the United States, only the Missouri-Mississippi River system has annual runoff greater than that of the Columbia River. The amount of water that the river carries each year is determined by the precipitation, sunlight, and air temperature in the basin,