Volcano, Floods
Volcano, Floods
Section titled “Volcano, Floods”2020-11-09 18:24:25
- Occurs in continental weak zones, only Barren Island
Floods
Section titled “Floods”- 40mil hectare flood prone
- Flash floods - very fast rise and recession, small volume and high discharge, occurs in hilly sloping lands, depression/ cyclonic storms causes, sudden release of water, warning using Doppler radars
Natural Causes
Section titled “Natural Causes”- Heavy rainfall,
- sediment deposition - river beds shallow,
- Cyclone - sea waves spreads water in coastal areas,
- Change in course, Tsunami, Lack of lakes
Anthropogenic Causes
Section titled “Anthropogenic Causes”- Deforestation, interference in drainage system,
- international dimension, population pressure,
- poor water and sewerage mgt
Vulnerability
Section titled “Vulnerability”- 85% rainfall in 3-4 months
- Brahmaputra basin : monsoon, fragile hills susceptible to erosion, frequent earthquakes, cloud bursts
- Ganga : mostly done by northern tributaries, RAJ MP experience of heavy floods, encroachment of flood plains
- NW River Region : inadequate surface drainage causes inundation and water logging, indiscriminate use of water for irrigation - drainage problem water logging, rivers change their course frequently
- Central and Deccan IN : inundation, destroy valuable crops, infra, millions rendered homeless,
NDMA Guidelines
Section titled “NDMA Guidelines”- Construct reservoirs, dams, other water storages
- Build embankments/flood Levees/ Flood Walls
- Restoring original Drainage system
- Channel improvement/ desilting/ dredging of rivers
- Diversion of flood water into naturally/ artificially constructed channel
- Catchment area treatment
Non Structural Measures
Section titled “Non Structural Measures”- Flood plain zoning : regulate land use,
- flood proofing : providing raised platform for shelter
- flood management plans,
- Integrated water resources management
- Apada Mitra #scheme- train community volunteers in prone districts
Urban Floods
Section titled “Urban Floods”Caused
Section titled “Caused”- heavy rainfall in short period,
- urbanisation,
- low drainage capacity
Impact and Mitigation
Section titled “Impact and Mitigation”- localised,
- disruption of water supply, communication etc
Mitigation
Section titled “Mitigation”- Pre Monsoon phase : estimation of emergency needs, familiarisation of stakeholders, ID teams to maintain drains and roads
- During : timely warning, response focuses primarily on emergency relief, mental health support
- Post : Rehab
NDMA Guidelines
Section titled “NDMA Guidelines”- Inventory of water supply,
- catchment as basis of design,
- Contour data determine boundaries
- Design flow ot estimate peak flow rates,
- Removal of Solid waste,
- Drain inlet connectivity,
- Rain Gardens
- ID areas at risk classification of structure, Response, Sanitation, Capacity Dev,
- Urban flooding cells to coordinate all activities
Existing Challenges
Section titled “Existing Challenges”- Less imp to comprehensive risk assessment,
- ignorance of mapping different factors,
- unsatisfactory coordination among diff institutions,
- lack info sharing
- disintegrated investment decision
- lack of consultation w/ stakeholder