Describe the source and effects of an El Nio event. What will ...

[james0929]

Describe the source and effects of an El Nio event.
   
  What will be an ideal response?

Question 2

Explain two ways in which human activity increases the danger of drought and desertification.
   
  What will be an ideal response?

[ntsoane kedibone]

Answer to Question 1

ANSWER: In an El Nio event, trade winds across the Pacific weaken and warm, shallow water accumulates at the eastern edge of the Pacific along the coast of South America. The event brings abnormally heavy rainfall to the western coast of the Americas from California to Peru. Australia, Indonesia, and southeast Asia experience drier than normal conditions that increase the danger of drought and wildfires. The event can affect global weather patterns.
A successful answer will
- identify the source of the event as a buildup of abnormally warm water along the coast of South America,
- identify increased rainfall along the eastern side of the Pacific as an effect, and
- identify increased drought in the western Pacific as an effect.

Answer to Question 2

ANSWER:
A successful answer will include two of the following:
- damming of rivers or increased use of water upstream reduces soil moisture downstream.
- overgrazing by livestock or wildlife, concentrated in an area by fencing or artificial water sources, breaks up soil, compacts deeper soil, and reduces water infiltration.
- cultivation decreases soil moisture by exposing more soil to heat and air.
- topsoil disturbed by cultivation can dry and blow away, exposing deeper soils to evaporative processes.