The basin comprises mountainous regions of the Himalayan ranges with dense forests, as well as the sparsely forested Shiwalik Hills and the fertile Gangetic Plains. The central highlands lying to the South of the Great Plains consist of mountains, hills and plateaus intersected by valleys and river plains. The important soil types found in the basin are sand, loam, clay and their combinations such as sandy loam, silty clay etc.
The annual surface water potential of the basin has been assessed as 525 km³ in India, out of which 250 km³ is utilisable water. Arable area of the basin in India is about 580,000 km², which is 29.5% of the total cultivable area of India.
The water related issues of the basin are both due to high and low flow. In India, the states of Uttar Pradesh, Bihar and West Bengal are affected by floods. As Bangladesh lies at the confluence of Brahmaputra River and Ganges River, it suffers from terrible floods almost every year. Many of the flood problems are caused by northern tributaries of Ganga such as Kosi and Mahananda. Besides these problems are also caused by southern tributaries.
The basin is a high earthquake risk area and experts warn that as many as a million deaths could be expected on the Ganges plain, as the southern flank of the Himalayas has not been active enough over past centuries to release the energy accumulated by the millimetre per week upward movement of the Indian plate.
