BENGALURU: As Karnataka and Tamil Nadu are engaged in a bitter tussle over the Cauvery, there is another aspect to the raging dispute that has received scant attention – the deficient rainfall in catchment areas in the last three years that has reduced the flow in the river. While the El Nino effect is said to be partly responsible for the change, experts say the main reason is indiscriminate and massive destruction of what they call ‘Monsoon Forests’ in Karnataka and Kerala.
The El Nino effect tapered off six months back, but it left its mark by changing the rainfall pattern. But, ecologists say, the large-scale felling of trees in Kodagu, Chikmagaluru, Mysuru and other districts after amending the Karnataka Tree Preservation Act has caused a more permanent damage. An effect of this is the huge reduction in rainfall in the Cauvery basin districts, they say.
Prof B Vijayalakshmi, climate expert and geographer, says rainfall has been deficient throughout the southern region this season, particularly in the Western Ghats belt. She says the Western Ghats, which plays a very prominent part in bringing rainfall to a semi-arid zone, has been subjected to systemic degradation over the last 50 years. “This has resulted in ecological imbalance in this region and so we are seeing decreasing rainfall. Unfortunately, south west monsoon is the only source of water for Cauvery. Northern parts of Kerala too have been witnessing deficient rainfall, which has considerably reduced inflows into the Kabini reservoir. The large-scale destruction of forests in the Palakkad region is a major factor,” she says.
Explaining the reasons for deficient rainfall, noted environmentalist Dr Yellappa Reddy says there is complete loss of hydro-geological character of the Western Ghats. “If the Himalayan glaciers are the main water source for Ganga and Yamuna, the Monsoon Forests of the Western Ghats are the main water source for the Cauvery, and many other rivers. With massive deforestation, the three-tier ecosystem that forms the life matrix has been completely disturbed. With break in evapo-transpiration (the moisture level in ambient air), one can see its detrimental effects in the form of flash floods, siltation and no cohesion in clouds, and finally, no precipitation,” he says.
Reddy adds, “Inexplicable crimes have been committed to the ecosystem in catchment areas and now how can you expect rains to occur or water to flow into the reservoirs? The granite exporters are a law unto themselves. Forests have been destroyed for setting up power stations. The power transmission line from Kushalanagara to Kutta resulted in the destruction of precious forests in Kodagu district.”
Geologist G Sitaram, who was formerly with the Geological Survey of India, says the effect of the mindless and continuing destruction of the ecosystem is showing on the topography of Cauvery basin districts. “The vegetation loss, slopes turning completely barren resulting in landslides and disturbances in the evapo-transpiration cycle have been due to the unscientific and destructive policies of the state government with no involvement of experts,” he says.
No government has given a thought to protection and development of Cauvery catchment areas, he says. “At least now, with doom staring at us, the state government should set up an expert committee comprising environmentalists, ecologists, hydrologists and geologists. A correlative analysis of geology, ecology and environment of catchment areas should be done and measures taken for their protection before it’s too late,” he concludes.