Uttarakhand Glacier Burst: Flash floods hit Uttarakhand’s Chamoli district on Sunday, due to a suspected glacier break. This has come months right after the PM Narendra Modi-led National Disaster Management Authority (NDMA) issued suggestions detailing the measures to cut down and deal with disasters stemming from Glacial Lake Outburst Floods (GLOFs). These suggestions had been issued in October final year, according to a report in IE. But what are these GLOFs and how can these glacial bursts be lowered?
GLOFs explained
The melting of the glaciers leads to water in glacial lakes becoming accumulated behind organic dams produced of pebbles, sand, ice and ice residue referred to as glacial or moraine dams. When water dammed by a moraine dam or glacier gets released all of a sudden, it outcomes in the occurrence of a flooding recognized as GLOF. The moraine dam has a weak structure and this can give way to an abrupt failure of the dam atop the glacial lake. The glacial lake holds a huge quantity of water, and a dam failure can possibly release millions of cubic metres of water in a incredibly brief time, major to a disastrous flooding downstream. Among other such events that have been recorded, peak flows have gone up to a whopping 15,000 cubic metre per second.
Due to the climate transform, glaciers in the Himalayas are retreating, major to an improve in glacial lakes. This has turn into a prospective threat for the infrastructure and life downstream. An inventory of water bodies and glacial lakes had been carried out by the National Remote Sensing Centre in the Himalayan Region of Indian River Basins involving 2011 and 2015. This study located that as a lot of as 352 water bodies and glacial lakes have been present in the Indus basin, although this figure was 283 for the Ganga river basin and 1,393 for the Brahmaputra.
Risk reduction: What requirements to be completed
According to the suggestions issued by NDMA, the initial step is to recognize and map such lakes, and then taking measures to make structural improvements that would avert these dams from sudden breaches. Moreover, for events exactly where such a breach happens, a mechanism would want to be place in spot to save lives as nicely as house.
Field observations, the lakes’ and dams’ geomorphologic and geotechnical traits, and records of previous events can aid in identifying lakes that are potentially harmful. Meanwhile, the NDMA has also recommended that modifications in water bodies, like formation of new lakes, can be automatically detected with the aid of Synthetic-Aperture Radar imagery. The authority also stated that remote monitoring of lake bodies could also be carried out from space by placing in spot strategies and protocols for the similar.
Moreover, pumping, siphoning out water or controlled breaching can be used to cut down the volume of water in such lakes, which would aid in structural management of these water bodies. Apart from that, a tunnel can also be constructed below an ice dam or via a moraine for this.
India’s preparation
There has been some work that has been carried out to recognize such lakes. However, other elements like establishment of a robust early warning technique, as nicely as the framework for improvement of infrastructure and building and excavation in vulnerable places are nonetheless a work in progress. In the suggestions, the NDMA stated that India did not have uniform codes for building, excavation or grading, as against other nations. It added that an successful way to cut down threat from GLOF, a no-expense strategy is to restrict building and improvement in vulnerable places. Moreover, habitation in prone places must also be prohibited, the NDMA had stated.
On the other hand, even globally the quantity of implemented and operation early warning systems for GLOFs is incredibly smaller, and in the Himalayan area, there are only 3 reported situations of the implementation of monitoring and sensor-based technical systems for GLOF early warning, and of these, one is in China and two are in Nepal. Meanwhile, India has a fantastic history of prosperous warnings concerning Landslide Lake Outburst Floods (LLOFs), and this dates back to the 19th century.