ii. Water bodies

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ii. Water bodies

The following are the various water bodies and the changes associated.

River	Although rivers cover only 0.1% of the land, these are considered a critical part of landscapes due to their major role in human life. This is corroborated by the fact that major settlements around the world have been around major rivers. For example Prayagraj, Agra on banks of Ganga River System; Shanghai- Yangtze River; New york–Hudson River, etc. Therefore, studying changes in the river and its regime becomes important.
Changes In River And Their Reasons	The cycle of Erosion- of the river defines its ever-changing nature depicted through different stages i.e, the young stage(small, swift river with vertical corrasion), mature stage(large volume with lateral erosion), and old stage(senile, less volume with only deposition work). Headward erosion leads to the retreat of slopes causing river captures as well as a reduction in relief height. Climate change and resultant Changes in Rivers. Rise in water temperature For ex: According to a recent study by Scientific Report, river water temperatures could rise to 35 degrees Celsius from the present 30 degrees Celsius by 20270-2100, and dissolved oxygen concentrations could drop in Indian rivers. Depleting sources of rivers such as glaciers and lack of snow deposition on mountain tops. Frequent changes in river courses. Increasing pollution in rivers- Central Pollution Control Board in 2018 found 351 polluted stretches of rivers in India. This is largely due to sewage and industrial waste discharge into the rivers. Construction of Multipurpose projects on rivers for energy as well as drinking and agricultural purposes. Interlinking of Rivers to effectively manage water resources by providing excess water from water-rich states to water-deficient states.For ex-: The Ken-Betwa link project Other Anthropogenic factors affecting changes in river flows such as illegal sand mining for constructions, overexploitation of fish resources, discharge of untreated sewage and industrial waste, etc.
Effects Of Changes On River Systems	Positive The cycle of erosion not only maintains the natural ecology of rivers but also: Deposit the fertile alluvium on flood plains necessary for agriculture. This leads to the formation of picturesque features such as waterfalls, canyons, gorges,ox-bow lakes, deltas, etc which help the tourism industry to flourish and provide a livelihood to local people Natural changes help in maintaining the ecological flow and aquatic life of rivers Multipurpose projects have added to the clean, green, and renewable energy capacity of countries. Interlinking of rivers is a noble solution for water-stressed areas
Effects Of Changes On River Systems	Negative Climate change has impacted rivers in varying degrees right from depleting their sources, rising water temperatures, etc to threatening the natural habitats of native fish and other organisms Pollution in rivers has only added to the already scarce water resources which have threatened water security. For eg: More than 600 million people in India are suffering from severe water shortages, according to the NITI Aayog’s Composite Water Management Index. Frequent changes in river courses lead to floods causing damage to human life and property and it also affects river ecosystems. For example, A significant flood in India in 2008 prompted the Kosi River to switch to an older channel, displacing 3 million people and claiming more than 250 lives. Multipurpose projects are not without negative effects such as sedimentation on river beds, dislocation of people, and destruction of flora and fauna, especially aquatic life. Fluctuations in river flow also affect the Hydrological cycle as these are an essential component that further aggravates the scarcity of freshwater. Interlinking of rivers also affects the natural flows of rivers which will affect aquatic ecosystems, ecological flow, etc. of the rivers. Rising disputes between states over sharing of river water due to water shortages among different regions. For eg: the Cauvery water dispute between Tamil Nadu, Kerala, Karnataka, and Puducherry. Dams and reservoirs over transboundary rivers threaten water security in downstream countries. For eg: India’s concern since 2015 when China operationalized its project at Zangmu on the Brahmaputra river