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
Nitrate in the Mississippi River Basin the mouth of the Mississippi River is growing. Drainage from crop fields has caused nitrate to leach into groundwater, which has adversely affected some drinking water sources in the Mississippi River Basin. In surface waters, high nitrate levels have led to instances of eutrophication, which have caused dissolved oxygen levels to significantly decrease in affected water bodies including the coastal waters of the Gulf of Mexico. Furthermore, altered nitrate to silicate ratios have caused coastal marine ecosystems to move away from a diatom based system to a less productive system. A possible way to lower the concentrations of nitrate is