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 84 percent of commercial fish landings. While areas accessible to salmon have been reduced over the past century through the construction of dams and the modification of river channels, this group of fish historically inhabited almost 13,000 miles of the Columbia River basin. Efforts from fishery management and state agencies, as well as the listing of several resident salmon stocks under the protection of the Endangered Species Act, has led to the re-establishment of accessibility to some parts of the Columbia River system for salmon. The regional return of salmon runs restores an important segment of local nutrient cycles, particularly