Droughts
BY
SHEENA BURKETT, DENNIS CESTERO, JAMES MILLAN
SHADEANA LUCUS, BLAKE ENGLES AND LANY HODGE
WHAT IS A DROUGHT?
A drought is a lack or insufficiency of rain for an extended period that causes a considerable hydrologic (water) imbalance and, consequently, water shortages, crop damage, streamflow reduction, and depletion of groundwater and soil moisture.
WHAT ARE ITÕS CAUSES?
It occurs when evaporation and transpiration (the movement of water in the soil through plants into the air) exceed precipitation for a considerable period. Drought is the most serious physical hazard to agriculture in nearly every part of the world.
HOW DO SCIENTIST MEASURE DROUGHTS?
There are four basic kinds of drought: 1) Permanent drought characterizes the driest climates; the sparse vegetation is adapted to aridity, and agriculture is impossible without continuous irrigation. 2. Seasonal drought occurs in climates that have well-defined annual rainy and dry seasons; for successful agriculture, planting must be adjusted so that the crops develop during the rainy season. 3. Unpredictable drought involves an abnormal rainfall failure; it may occur almost anywhere but is most characteristic of humid and subhumid climates. Usually brief and irregular, it often affects only a relatively small area. 4. Invisible drought can also be recognized: in summer, when high temperatures induce high rates of evaporation and transpiration, even frequent showers may not supply enough water to restore the amount lost; the result is a borderline water deficiency that diminishes crop yields.
WHAT ARE EFFECTS OF AT DROUGHT?
In a disaster of potentially massive consequences, tens of millions of people are at risk from persistent droughts in East Africa and South Asia. Across vast areas of both continents, crops have wasted away, wells are dry, livestock are dying and the land has become a desiccated sprawl of dust. Only large-scale relief efforts can prevent what could become wide scale starvation, disease and death.
WHERE DO DROUGHTS USUALLY HAPPEN?
Ethiopia, Eritrea, Somalia, Kenya, Asia, India, Arizona and places that are either desert- like or have a great amount of sunlight.
HOW ARE DROUGHTS IMPORTANT IN EARTH SCIENCE?
Droughts are important to Earth Science because it is something that happens within EarthÕs atmosphere. Earth Science is the study of earth, whereas, droughts are natural disaster and is of the earth. I found two reasons that say why droughts are important to Earth Science.
INTERESTING FACTS:
1) DROUGHTS ARE THE MOST PHYSICAL HAZARD TO AGRICULTURE.
2) THERE ARE FOUR DIFFERENT TYPES OF DROUGHTS.
3) A DROUHGT IS A COMPLEX PHENOMENON THAT CAN BE DEFINED FROM SEVERAL PERSPECTIVES.
4) MOST DEFINITIONS OF A DROUGHT REFER TO ABNORMAL DRYNESS.
5) A DROUGHT IN 1930 LASTED FOR EIGHT YEARS BUT THIS ONLY HAPPENS ONCE OR TWICE A CENTURY.
6) GLOBAL WARMING INCREASES THE CHANCES THERE WILL BE MORE SEVERE DROUGHTS.
7) A DROUGHT IS DIFFERENT FROM DRY CLIMATE.
TO KNOW MORE ABOUT DROUGHTS YOU CAN VISIT THE FOLLOWING WEBSITES:
For a good definition of a drought you can visit
For information on changes in weather try
For an explanation of the effects on humans and animals go to