Elucidate the major threats faced by river ecosystems in India while highlighting the link between deforestation in catchment areas and its harms to rivers.
Rivers play a prominent role in the water cycle as they act as drainage channels for surface water. Due to increasing population, water demand is increasing day by day making already insufficient water scarcer. Since groundwater has its limits, rivers are becoming more and more important. However, most rivers are overexploited, as per the studies, the current minimum flow in rivers is only one-third of what is required. Major threats faced by the rivers:
- Deforestation in catchment area: Air over forest absorbs moisture from trees and creates rain, the loss of trees means less rain and less water on the ground. Forests also provide tiny particles like pollen and spores which act as a condensation platform for raindrops. Fewer trees, means less condensation, reducing the amount of water in rivers due to less rainfall.
- Planting of exotic trees along banks: Change in vegetation or loss of tree, this change in vegetation cover affects percolation of water
- Dumping of waste, untreated sewage cause the biological death of rivers, water turns toxic leading to the harmful effect on fishes and plants.
- Diversion and obstruction of river flow, for example, excessive dams prevent minimum flow which is essential for the sustainability of river.
- Sand mining destroy river channel causing water to run off
- Encroachment on river banks increases the risk of disasters like Uttrakhand floods
- Due to climate change, there is variation in rain fall pattern leading to more frequent droughts and floods making life in floodplains more vulnerable.
River conservation is a collective effort which requires participation of all stakeholders. Sustainable use of water resources is imperative for the continuity of life on earth.