1. Causes of Droughts
1.1. Climate change due to global warming
1.1.1. Causes droughts in places of drier climate
1.1.2. E.g. Sahel,Africa
1.2. Global atmospheric processes
1.2.1. El Nino and La Nina
1.2.2. These natural phenomena cause change in rainfall patterns
1.3. Reduced forest cover
1.3.1. Deforestation lead to less cloud formation
1.3.2. Thus,less rainfall
1.4. Amid or Semi-Arid regions
1.4.1. Delayed rain or insufficient rainfall
1.4.2. Monsoon einds delayed,dry seasons prolonged
1.5. Heavy dependence on river and groundwater
1.5.1. Population increase
1.5.2. More water needed for homes,industries and agriculture
2. Impacts of Droughts
2.1. Desertification
2.1.1. Spread of deserts into areas where there is no rain
2.2. Forest fires
2.2.1. Dry vegetation catches fire very easily
2.2.1.1. Smoke spreads to neighboring countries when the wind blows
2.2.2. Haze
2.2.2.1. Pollutes the air
2.2.2.2. Environmental hazards
2.2.2.2.1. Eye irritations
2.2.2.2.2. Breathing difficulties
2.2.3. Civil servants to put out fire
2.2.3.1. High economic loss
2.3. Dehydration
2.3.1. Lack of water as rivers and lakes run dry
2.3.1.1. Animals and people suffer from dehydration
2.3.1.2. Plants wilt
2.3.1.2.1. Crop production failure
2.3.1.3. Severe damages to coastal ecology
3. Causes of floods
3.1. Melting snow
3.1.1. New node
3.2. Storm surges
3.2.1. Strong winds raise the waves in the ocean to high levels
3.3. Deforestation
3.3.1. No vegetation to hold the soil when eroded
3.3.2. Increased surface runoff
3.4. Tsunamis
3.4.1. flood and destroy coastal settlements
3.5. Earthquakes
3.5.1. movements of the earth's surface results in landslides
3.5.2. soil loosened
3.6. Urbanization
3.6.1. excessive clearance of land
3.6.2. increase amount of surface runoff
3.7. Excessive rainfall
3.7.1. Places experiencing Tropical Monsoon Climate have seasons of heavy rain
4. Impact of floods
4.1. Loss of lives
4.1.1. People attracted to stay near river that floods therefore impact is bigger
4.2. Damaged to property and infrastructure
4.2.1. Homes' power lines and power supply destroyed
4.3. Spread of diseases
4.3.1. Makeshift shelters lack sanitation
4.3.1.1. Outbreak of cholera and malaria
4.4. Fertile soil for agriculture
4.4.1. Regular flooding makes the soil surrounding the river fertile and suitable for farming
4.4.2. Nile Delta in Egypt
4.5. Damage to environment
4.5.1. Destroy trees and natural habitats of animals
4.5.2. Tsunami