O-Level Geography Chapter 2 Climate Floods and Drought

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Floods

Flood is a temporary covering of land by water which is dry. They can be caused by variety of factors like Heavy monsoon rainfall accompanied with melting of snow and ice in glaciers causing excess of water in rivers, dam or barrage failure, unusually high tides in coastal areas and by a tsunami The indus tributaries overflow almost every year but only sometimes the flood risk is serious.

Floods can also be caused by following human reasons

• Deforestation
• failure to heighten or strengthen embankments
• poor medical and communication facilities in aftermath ofdisaster
• inadequate warning systems to allow people time for escapeBenefits of flood
• restoring underground water supplies,
• filling reservoirs of dam
• makes the soil fertile by alluviam deposits
• increases fish production in the sea and land

Reducing Effects of Floods

• Dams could be built to contain and regulate the flow of water and prevent flash floods
• Advanced warning systems should be installed in flood prone areas to warn people to get out before it’s too late
• Medical and transport facilities be regularly updated and checked
• Embankments and levees should be heightened and strengthened
• afforestation and re-afforestation projects should be carried out in Northern Mountains to reduce run-off and thus reducing chances of flash floods

Droughts

There are four types of droughts

Permanent drought: Occurs when crop cultivation is highly dependent on irrigation only

Seasonal drought: Occurs when rainy areas faces dry seasons for longer period then usual

Invisible drought: Occurs when water deficiency reduces crop yield but does not destroy them

Unpredictable drought: Caused by abnormally low rainfall in areas of humid climate

Effects

● Crop yields can be dramatically reduced and livestock production could fall (milk, eat etc). This can raise prices of goods and affect price of exported goods making them uncompetitive in international markets thus harming national interests

● Dust storms can occur, when drought hits an area suffering from desertification and erosion. This can lead to siltation in reservoirs of dam, hampering electricity generation and weakening dam’s foundation

● Habitat damage, affecting both terrestrial and aquatic wildlife

● Malnutrition, dehydration and related diseases could affect millions

● Mass migration causing the increase in internal refugees or international refugees Reduced electricity production could occur as reduced water flow through hydroelectric dams leads to low industrial production and less exports resulting in less foreign exchange

● Shortages of water for industries like (juice etc), which affects employment and GDP

● Social unrest may follow leading to instability, which can discourage foreign investment thus local sectors may suffer from outdated machinery techniques etc resulting in low production

● War could occur over natural resources, including lakes and fertile areas etc

● Wildfires can become common and can cause health hazard to people