From UPSC perspective, the following things are important :
Prelims level : Nothing much
Mains level : Floods - causes - impact
Floods impact the poorest strata of society the most, causing a loss of lives, livelihood options, and assets. There is a need for assessment of floods from a ‘sustainable development’ perspective.
Causes for floods
- The root cause of such floods is the high precipitation levels.
- Anthropogenic factors like unscientific development and over-exploitation of nature aggravate the damages.
- The global climate has been changing in an unpredictable manner. As per an IPCC report, the Global Green House Gases emissions grew by 70% between 1970 and 2004. Global warming has critical effects on the hydrological cycle.
- In Kerala, a structural transformation and changing patterns of land use are affecting its environment. A loss in a wetland area will naturally impact the ability to handle floods.
Impact of floods
- The changing precipitation alters the hydrological systems, resulting in floods and droughts in different regions.
- Floods wash away topsoil and substantial biodiversity of the area, resulting in a reduced river-water flow, death of earthworms and spread of viral and bacterial diseases among crops.
- Adequate precautions through dam management and timely public alerts.
- In construction, it is important to take appropriate decisions on the type and size of the structure, location, materials, and permissible damage it will cause to nature.
- We need to account for the damage done to natural ecosystems while estimating losses suffered due to natural disasters.