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 which varies from year to year. West of the Cascade Range, most of the winter precipitation falls as rain, but in the Cascade Mountains and eastward, precipitation through winter is snow. Snowmelt in the mountains begins to reach the river during early to mid-spring. About 30 percent of the streamflow in the Columbia River occurs between January and March (primarily from rainfall) and about 30 percent occurs between April and June (from a combination of rainfall and snowmelt). Coastal upwelling, river discharge, tidal mixing, estuarine circulation, climate oscillation, and remineralization, are sources or sinks for the Columbia River basin nutrient