Scientists find out why Chennai flood

The extreme El Nino conditions in 2015 and the warming trend in the Bay of Bengal contributed equally to the unprecedented heavy rainfall witnessed in Chennai for three days from November 30 to December 2, 2015.

A study by the University of Hyderabad and the Indian Institute of Technology – Bombay suggests that the extreme El Nino that occurred in 2015 played an important role in Chennai’s heavy rainfall.

Reason for flood

  • Another factor that seems to have played an important role is the consistent warming of the Bay of Bengal off the coast of Tamil Nadu and Andhra Pradesh.
  • The extreme El Nino that occurred in 2015 played an important role in Chennai’s heavy rainfall.
  • After 1982 and 1997, the 2015 event also turned out to be an extreme El Nino event.

El Nino generally causes less than normal rainfall in the case of the southwest monsoon. In contrast, it brings about above-normal rainfall during the northeast monsoon. This is because of the difference in seasonal wind patterns between the two monsoons.

El Nino Effect

  • El Nino events are associated with a warming of the central and eastern tropical Pacific.
  • El Nino occurs when the normal trade winds weaken (or even reverse), which lets the warm water that is usually found in the western Pacific flow instead towards the east.
  • This warm water displaces the cooler water that is normally found near the surface of the eastern Pacific, setting off atmospheric changes that affect weather patterns in many parts of the world.
  • These consequences include increased rainfall across the southern tier of the US and in Peru, and drought in the West Pacific.

El Nino effects on Indian Monsoon

  • El Nino signal shows up in atmospheric circulation, the local sea surface temperature can also change.
  • It generally causes less than normal rainfall in the case of the southwest monsoon.
  • In contrast, it brings about above-normal rainfall during the northeast monsoon.
  • This is because of the difference in seasonal wind patterns between the two monsoons.

Source : The Hindu

GS II : Important Geophysical phenomena


NDMA to conduct mock exercise in Delhi

National Disaster Management Authority (NDMA) in collaboration with the Delhi Government will conduct a mock exercise to improve preparedness and response mechanisms of the local administration in the event of an earthquake.

About mock exercise

  • The exercise will cover all the 11 districts of Delhi.
  • Preparedness measures required to be taken at individual, societal and institutional levels to minimise the effects of an earthquake were discussed in detail.
  • NDMA experts will brief the stakeholders on the activation of Incident Response System (IRS), on their roles and responsibilities at each level to improve coordination.
  • Also created various disaster situations involving residential high-rise buildings, hospitals, schools, metro stations, shopping malls and petroleum depots and sought response plans from the participating officials.
  • Departments such as the Army, Health, Police, Firefighting, Civil Defense, Transport, Electricity, Public Relations and Traffic Control participated in the preparatory meetings.

Source : Pib

GS III : Disaster and disaster management

NDMA conducts its first mock exercise on forest fire in Uttarakhand

National Disaster Management Authority (NDMA) conducted a first-of-its-kind State-level mock exercise on forest fire in Uttarakhand.

Key facts

  • The mock exercise, aimed at assessing the efficacy of integrating the preparedness and response mechanisms of the forest department with those of the district administration, has been conducted in collaboration with the State Government.
  • The exercise is significant as almost 70 per cent of the State’s geographical area is under forests and incidents of forest fires are commonplace.
  • The simulation exercise was conducted simultaneously at multiple locations.
  • It includes residential areas adjoining forests, across all 13 districts covering different types of forests and varying degrees of severity of forest fires.
  • The exercises were conducted in coordination with various agencies, such as fire, forest, Army, health, police, National Disaster Response Force (NDRF) and State Disaster Response Force (SDRF) and civil defense.

National Disaster Management Authority

  • An agency of the Ministry of Home Affairs whose primary purpose is to coordinate response to natural or man-made disasters and for capacity-building in disaster resiliency and crisis response.
  • NDMA was established through the Disaster Management Act enacted by the Government of India in December 2005.
  • 9-member board chaired by the Prime Minister of India. The remainder of the board consists of members nominated based on their expertise in areas such as, planning, infrastructure management, communications, meteorology and natural sciences.
  • The day-to-day management of the agency is overseen by the office of the Vice Chair.
  • The agency is responsible for framing policies, laying down guidelines and best-practices and coordinating with the State Disaster Management Authorities (SDMAs) to ensure a holistic and distributed approach to disaster management.

Covered on 18 April 2017

Source : Pib

GS III : Disaster and disaster management

NDMA to conduct mock exercise on forest fire

The National Disaster Management Authority (NDMA) will conduct its first-ever mock exercise on forest fire in Uttarakhand April 20, 2017. The mock exercise will be part of a three-day event.

Key Fact 

  • To help improve the preparedness and response mechanism in the event of a forest fire.
  • The mock exercise will be conducted on the principle of Incident Response System (IRS), which identifies stakeholders and clearly attributes roles and responsibilities to each one of them.
  • It will enhance preparedness and ensure a swift response by reducing confusion and chaos.
  • It will help in filling gaps, ensuring better communication and improving coordination among various stakeholder agencies.
  • Also generate awareness among the local population about the Do’s and Don’ts to be followed to prevent and respond to a forest fire.
  • Senior officials from all the important departments such as the Army, the National Disaster Response Force (NDRF), forest, health, police, firefighting, Civil Defense, transport, electricity, public relations, etc. will participate in the exercise.

Forest fire and Vulnerability

  • The total forest cover of the country as per State of Forest Report 2003 is 678,333 km², which constitutes 20.64 percent of the geographic area of the country
  • Along with various factors, forest fires are a major cause of degradation of Indian forests.
  • According to a Forest Survey of India Report, about 50 percent of forest areas in the country are fire prone ranging from 50 percent in some states to 90 percent in the others.
  • About 6 percent of the forests are prone to severe fire damage.
  • The available forest fire statistics are not reliable because they under estimate fire numbers and area burned.
  • The reason behind this is attributed to the fear of accountability.
  • Forest Survey of India in a country-wide study in 1995 estimated that about 1.45 million hectares of forest are affected by fire annually.

Need for such Management/excercise

  • Loss of timber, loss of bio-diversity, loss of wildlife habitat, global warming, soil erosion, loss of fuelwood and fodder, damage to water and other natural resources, loss of natural regeneration.
  • Estimated average tangible annual loss due to forest fires in country is Rs.440 crore (US$ 100 millions approximately)
  • Health problems leading to diseases
  • Loss of livelihood for tribal people and the rural poor, as approximately 300 million people are directly dependent upon collection of non-timber forest products from forest areas for their livelihood.

Source : Pib, Fire Situation in India, Disaster Management – Agritech

GS III : Disaster and disaster management