Climatic Hazards: Causes and Concerns

Introduction

• Cyclones and Hurricanes• Floods• Drought• Impacts• Strategies

Climatic Hazards

• Hazard – something that is likely to cause damage to people and property– Tectonic Hazards– Climatic Hazards

Tropical Cyclones and Hurricanes• • Tropical cyclones form only over warm ocean waters near the equator. • • To form a cyclone, warm, moist air over the ocean rises upward from near

the surface. As this air moves up and away from the ocean surface, it leaves is less air near the surface. So basically as the warm air rises, it causes an area of lower air pressure below.

• • Air from surrounding areas with higher air pressure pushes in to the low pressure area. Then this new “cool” air becomes warm and moist and rises, too. And the cycle continues…

• • As the warmed, moist air rises and cools the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean’s heat and water evaporating from the ocean surface.

• • As the storm system rotates faster and faster, an eye forms in the centre. It is very calm and clear in the eye, with very low air pressure. Higher pressure air from above flows down into the eye.

Most affected areas

• Coastal areas– Wind– Tides– Precipitation– Large populations– Once on land it dissapates

Floods

• Overflowing rivers• Ice dam bursts• River deltas especially hit hard• “perfect” conditions when flooding and

typhoon hit.

Drought

• Monsoonal areas of the world see more drought conditions.– Tropics – wet and dry season– El Nino and La Nina effects

Climatic Hazards Impacts

• Social losses– Deaths of friends/relatives

• Economic losses– Damage to homes, businesses– Loss of possessions– Loss of crops and animals– Disruption of trade– Public utilities loss– Poor sanitation leading to disease– Starvation

Strategies

• Cyclones– Better weather modeling– Limiting population density along coasts– Cyclone shelters– Better govt. response

• Drought– Water conservation– Stopping runoff and soil erosion– Improving soil after runoff using compost pits

Conclusion

• Cyclones and Hurricanes• Floods• Drought• Impacts• Strategies