1 / 6

Lesson 4 Drought and Floods

Lesson 4 Drought and Floods . Chapter 2 – Earth’s Waters. Droughts. Are usually caused by dry weather systems that remain in one place for weeks or months at a time. Long-term droughts can devastate regions. A drought reduces the supplies of groundwater and surface water. .

kioshi
Télécharger la présentation

Lesson 4 Drought and Floods

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lesson 4 Drought and Floods Chapter 2 – Earth’s Waters

  2. Droughts • Are usually caused by dry weather systems that remain in one place for weeks or months at a time. • Long-term droughts can devastate regions. • A drought reduces the supplies of groundwater and surface water.

  3. Predicting and Preparing for Droughts • Droughts are difficult to predict. • As soon as the level of rainfall drops below normal, state agricultural officials may contact farmer to warn them. • Washing cars and watering lawns are two activities that can be curtailed during a drought.

  4. Floods • Small or large, however, all floods occur when the volume of water in a river increases so much that the river overflows its channel. • A flooding river can uproot trees and pluck boulders from the ground. • Floods are the most dangerous weather-related events in the United States. • http://www.youtube.com/watch?v=WqcuX5f6Tk0&feature=related

  5. Flash Floods • A flash flood is a sudden violent flood that occurs within a few hours, or even minutes of a storm. • Some of the most dangerous floods occur in the deserts of the southwestern United States. • http://www.youtube.com/watch?v=tHWwvMrOj5E&playnext=1&list=PL0A6EEAE81D004B3D

  6. Flood Precautions • Advance warnings help reduce flood damage and loss of life. • Building dams is one method of flood control. • There is also a natural defense against floods – sediments. • Levees that form naturally help keep the river inside its banks. • Flood waters can wash into wells and water treatment plants, polluting the water.

More Related