Tag: social studies

Brahmaputra River.

Assam is the state prone to flood in India. Area prone to flood in Assam is 3.15 million hectares. Assam faces frequent flood problem because it lies on the basins of Brahmaputra and Barak rivers. 

Floods can have negative environmental consequences, such as soil erosion, release of pollutants and excess sediments into waterways and the ocean, dispersal of weed species, and negative impacts on fish and other aquatic life. Floods can also have positive environmental consequences, such as recharging groundwater systems, filling wetlands, moving useful nutrients around the landscape, and triggering breeding events (for example, of water birds).

Flood risk in new developments can be reduced by restricting the location of development (zonings) and placing controls (regulations) on development. In existing developed areas, risk can be reduced by modifying flood behaviour (for example, through dams, detention basins, levees, waterway modifications), property modification measures (for example, land filling, flood proofing, house raising, removing developments), and response modification measures (for example, upgrading flood evacuation routes, flood warnings, flood evacuation planning, flood education programs).

Flood warnings should provide information on what the threat is, what action should be taken, by whom and when. While it is desirable for flood warnings to be accurate, warnings are predictions about the future, so there is inevitably some uncertainty. Accuracy needs to be balanced with timeliness, to allow enough time for appropriate action. Warnings are most likely to reach different audiences and to be heeded if they come from multiple trusted sources.

In the future, climate change is likely to result in an increased chance of flash floods and coastal inundation. Australia’s growing population and urbanization are likely to place increased pressure on our waterways and to increase the chance of flooding in cities and the number of properties and people exposed to floodwaters.

The Probable Maximum Flood (PMF) is an estimate of the largest possible flood that could occur at a particular location, under the most severe meteorological and hydrological conditions as they are currently understood.