Uttarakhand floods

Introduction

• The staggering collapse of part of a glacier in Uttarakhand’s Nanda Devi mountain and the ensuing floods that have claimed many lives come as a deadly reminder that this fragile, geologically dynamic region.

Reason of flash floods

• A significant slice of the glacier, dislodged by a landslide, produced roaring torrents in the Rishiganga and Dhauliganga rivers in Chamoli district, trapping unsuspecting workers at two hydro power project sites (Tapovan project and Tapovan-Vishnughad project).

Risks of hydroelectric power projects

• Once the crucible of environmentalism, epitomised by Sunderlal Bahuguna, Gaura Devi and the Chipko movement.
• The State’s deep gorges and canyons have attracted many hydroelectric projects and dams, with little concern for earthquake risk.
  • Example: Red flags have been raised repeatedly, particularly after the moderate quake in 1991 in the region where the Tehri dam was built and the 2013 floods that devastated Kedarnath, pointing to the threat from seismicity, dam-induced microseismicity, landslides and floods from a variety of causes, including unstable glacial lakes and climate change.
• India is heavily invested in dam development and growth of hydropower, largely in the Himalaya region — especially to cut carbon emissions.
  • Data: By one estimate, if the national plan to construct dams in 28 river valleys in the hills is realised in a few decades, the Indian Himalayas will have one dam for every 32 km, among the world’s highest densities.
• There may be a miscalculation for reasons, including potential earthquake impacts, monsoonal aberrations that could repeat a Kedarnath-like flood, severe biodiversity loss and extreme danger to communities downstream.
• The life of dams is often exaggerated, and siltation, which reduces it, is grossly underestimated:
  • Case study: In the Bhakra dam in Himachal Pradesh, for instance, siltation was higher by 140% than calculated.

Way forward

• The need is to rigorously study the impact of policy on the Himalayas and confine hydro projects to those with the least impact.
• Relying more on low-impact run-of-the-river power projects that need no destructive large dams and reservoirs.

Glacial Lake Outburst Flooding

• A glacial lake outburst flooding (GLOF) occurs when a breach in the glacial lake causes a sudden surge downstream.
• Such lakes are formed when glaciers erode land, melt and over time become a large mass of water in the depression formed, and these can be breached, causing floods downstream.
• In India the status of glacial lakes is checked by Central Water Commission.

Sri Lanka clears a Chinese energy project 50 km from Rameshwaram

Sri Lanka govt. has recently cleared a Chinese energy project in 3 islands near to Jaffna peninsula.

• Sinosoar-Etechwin Joint Venture will be executing the project.

• These hybrid renewable energy systems projects will be based in Nainativu, Delft and Analaitivu islands located in Palk Bay.

• The islands are connected to the Jaffna peninsula with a ferry service & are about 50 km away from Rameshwaram