Shrinking forests diminishing rivers in Uttara Kannada districts: Study

A study by the Indian Institute of Science has found that the proportion of evergreen forests in the Uttara Kannada district has declined from 56.07% to 24.85% in four decades, leading to a deficit of water in rivers.

Led by TV Ramachandra of IISc's Energy and Wetland Research Group, four researchers, studied the land use in Uttara Kannada district between 1973 and 2018 to understand the change in hydrological and ecological dynamics. About 1.59 lakh acres of forest land was diverted for industries, hydro and nuclear power projects.

Contiguous forests, which made up 62.17% of the total forest cover have been reduced to 24.74%, thanks to fragmentation and erosion of forests with native species which are crucial for sustaining the aquatic ecosystems.

"Our field studies showed that catchments with over 65% vegetation of native species had water all the 12 months. In monoculture plantations, it was six to eight months while in degraded areas with less than 30% forest cover the water availability was limited to four months," Ramachandra said.

The availability of water directly affects the livelihood of people a majority of whom are engaged in agriculture and related activities. "Monoculture plantation also affects pollination, which will have a direct impact on productivity," he said.

The study found that forest cover in the Aghanashini riverscape fell from 72.15% in 1973 to 24.09%. The moist deciduous forest, which was less than 10% jumped to about 26%.

Similarly, the dams in Kali river basin were responsible for the reduction in forest cover from 87.26% to 54.24%. The stories of Sharavathi and Bedthi (Gangavali) were no different.