Context: Odisha has come out with a unique flood hazard atlas aided by satellite imagery, which is expected to help the coastal state manage floods more efficiently. The atlas was released by Odisha Chief Minister at the State-level Natural Calamity Meeting.
Mains: GS III- Disaster and disaster management.
- Atlas would serve as a useful resource of information for policymakers, planners and civil society groups.
- Atlas is compiled on basis of historic flood inundation captured via satellite imagery over 18 years period from the year 2001 to 2018.
The Atlas will help the authorities in many ways:
- Better preparedness: A more concise focus on the effects and impacts of the flooded area is possible during the early planning stages.
- Risk reduction or mitigation techniques can be recommended for the same portion of the study area.
- Location, severity, or frequency of hazard can be analyzed more easily.
- Proper assessment of area: A study area or a sub-area can be expanded, reduced, or deleted. Study areas can be divided into sub-areas requiring more information, additional assessments, or specific reduction techniques.
- Risk evaluation: A more realistic evaluation of risks to new development is possible. Appropriate hazard reduction techniques can be more easily developed to deal with an emergency situation.
- Rehabilitation planning: It could be initiated in advance with proper coordination among different central and state agencies.
The National Remote Sensing Centre (NRSC) of the Indian Space Research Organisation (ISRO), Hyderabad had taken the study on flood hazard zonation for Odisha.
Key Findings of the study:
- Every year vast areas of Odisha are inundated when there is flooding in major rivers of the state, viz. Mahanadi, Subarnarekha, Brahmani, Rushikulya and Brahmani, Rushikulya and Baitarani. Also, as per Odisha State Disaster Management Authority (OSDMA), damages due to floods are mainly caused by Mahanadi, Brahmani, and Baitarani, which have a common delta where floodwaters intermingle and when in-series simultaneously cause havoc.
- Few districts in the western and southern parts of Odisha are prone to flash floods which are caused due to instant run-off from hilly catchment areas of rivers like, Vamsadhara and Budhabalanga. The entire coastal belt is prone to storm surges, which is commonly accompanied by heavy rainfall which then makes the estuary region vulnerable to both storm surges and river flooding. Few districts in Odisha’s western and southern parts are prone to flash floods.
- As per NRSC analysis during 2001-2018, about 8.96% (13.96 lakh hectares) of land in Odisha were affected by floods. Out of this 13.96 lakh hectare flood-affected area, nearly 2.81 lakh hectares of land falls under high inundated flood hazard categories (7-9 times) to very high inundated flood hazard categories (10-14 times).