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 nitrogen, and silicate are strongly impacted by increased residence times in reservoirs created by dam construction throughout the Columbia River Basin. Exact nutrient retention rates can vary between 16 and 98 percent depending on local hydrology, reservoir design, and location in the basin. However, this increase in nutrient retention rates in the Columbia River basin has generally modified the relative ratios of available nutrients from their natural state, which has subsequently altered the efficiency of compound usage by primary producers such as diatoms. Diatoms are directly affected by the hydrodynamic changes that reservoirs create. The slow moving, fresh water in