10.6: Importance of Rivers

Human Use and Management of River Resources

Water is a very significant resource and rivers provide freshwater which is a highly desired resource that needs to be sustainably managed. Historically rivers have been very significant for humans with civilizations developing around rivers.Not only have rivers supplied water for domestic consumption but rivers have formed chief highways for commerce and transport. Even during ancient civilizations, building materials were transported by rivers. Some highly navigable waterways that have been commonly used by humans are Yangtze, Amazon and Nile. St Lawrence waterway is another highly navigated waterway passage connecting the Great Lakes area to the Atlantic Ocean. 

Erosion, transportation and deposition carried out by rivers have advantages and disadvantages from anthropogenic point of view. The presence of rapids, cataracts and waterfalls make navigation difficult. However these features also attract tourists and thus help earn foreign revenue.Waterfalls can also be harnessed for hydro electric power. Generation of hydro electric power positively impacts industries reliant on them for power. Dams that are constructed for harnessing power often alter downstream waterflow by holding back or releasing flood water based on need. Thus, dams have often saved civilizations from disastrous floods. Sometimes when a river deposits a lot of sediments at a harbor area then port authorities may have to take part in dredging which may increase the port maintenance costs. 

Rivers have always played a positive impact on agriculture. Alluvial deposits by rivers are very fertile and positively impact agriculture. The Indus - Ganga plains in India are very fertile and heavily cultivated. This region is known for its cotton and rice cultivations. In Egypt and Thailand irrigation canals are built to facilitate crop cultivation. Organic matter carried down by the rivers provide food for fish and freshwater fishing is a very important activity among many rivers and lakes.  

Many of the world's important rivers like Nile, Ganges, Indus flow through multiple countries requiring them to draw treaties regarding water usage. If a country in the upper courses constructs many dams and reduces the flow of water to countries in the lower courses, the country with reduced water access would be unhappy. The downstream countries' agriculture, industries, water security would be affected leading to disputes. Sometimes upstream countries build large dams to control river's flow and leverage diplomatic negotiations. Indus Waters treaty shows that cooperation over shared water usage is more common than conflict. Climate change initiated changes in river water flow have however posed to be an issue that global politics is currently facing and there has been an increased call for international co operation. International water law provides guidance regarding equitable and reasonable utilization of water. Johannesburg, Mexico City and Kabul are at risk of running out of water thus proving the need for sustainable management of freshwater.