Altered River Flows and Nature's Fury

Need for Efficient Water Resources Management The theme of this year’s World Environment Day is Ecosystem Restoration. Ecosystem restoration can take many forms, such as growing trees, greening cities, rewilding gardens, changing diets or cleaning up rivers and coasts. In this regard, Simi S Nair says that human-induced drivers, such as dams, sand mining, over-extraction of groundwater, land use land cover changes, and indiscriminate disposal of untreated non-biodegradable solid wastes have significantly altered river ecosystems, impaired river water quality, and simultaneously increased the severity of disasters, such as droughts and floods.

- Simi S Nair

In recent years, India has witnessed several natural as well as anthropogenic disasters. The devastating effects of the 2018 floods in Kerala have been a wake-up call to understand the threat of anthropogenic activities on river catchments. Accelerated implementation of developmental projects has caused irreversible damages to river ecosystems leading to considerable loss of life and property. Rivers are often viewed as an economically valuable resource for driving agriculture, tourism, aquaculture, and hydropower sectors. However, their environmental value far exceeds the value of the water they carry. Rivers not only function as a natural habitat to innumerable species of living organisms, they also nourish wetlands which in turn deliver numerous ecosystem services important for the survival of all forms of life, such as supply of clean water, flood risk reduction, protection from storms and droughts, prevention of soil erosion, groundwater recharge, nutrient retention, and maintaining local climatic conditions. However, human interventions in the form of construction of dams, illegal sand mining, overexploitation of aquifers, alteration of land use land cover (LULC) patterns, and indiscriminate disposal of untreated liquid and solid wastes, have negatively impacted several ecosystem services offered by rivers.

Changing Land Use Land Cover Patterns are Affecting River Flows