Kidz Quiz Answers
#1 Name an event that could cause a flood.
There are a number of events:

  • Heavy rainfall in a short period of time. When this happens, a huge amount of water falls with little time to soak into the ground. This creates a lot of runoff which may lead to flooding.
  • Runoff from deep snows. In the spring, or even during the winter during a warm spell, deep snows may melt. Even though the snow is melting, the soil is still frozen and the water has no place to soak into. This situation leads to a tremendous amount of runoff and may result in flooding.
  • Soil that has so much water in it that it cannot hold anymore (a condition known as saturated soil) or frozen soil that doesn't allow runoff to soak into it.
  • High river, stream, or reservoir levels caused by unusually large amounts of rain.
  • Ice jams in rivers. An ice jam happens when large chunks of floating ice pile up when they hit a bend in the river, a bridge, or some other obstacle, and water backs up causing upstream flooding.
  • Urbanization. When land is developed into houses or shopping centers, the areas where runoff may be absorbed are reduced, resulting in a lot of water with no place to go. Areas where water cannot adequately be absorbed are known as impervious surfaces. Examples of impervious surfaces are asphalt roads and parking lots.

These links from the U.S. Geological Survey will help you to learn more about:
Runoff
Impervious Surfaces
Impervious Surfaces

#2 What are the two types of floods that can occur?
There are two basic types of floods:
  • Regular River Flood. This happens when water levels slowly rise and spill over the banks of a river.
  • Flash Flood. This is a more dangerous type of flood which occurs when a wall of water quickly sweeps over an area. Nearly 75% of all flood deaths result from flash floods.
#3 What is the flat area on either side of a river or a stream called?
A flood plain. Flood plains are areas that are usually underwater during a flood and contain soils that are able to absorb large amounts of water.
#4 What is the name for the structure an engineer would build to protect communities from flooding?

There are two possible answers:

  • A levee - a bermlike structure that acts as a barrier to flood waters.
  • A dam - a barrier which impounds water.
#5 Name a natural feature that protects communities from floods.

 Actually, there are several natural features that protect communities from floods:

  • Wetlands. Wetlands are marshy, wet areas which are important habitat for many types of wildlife and plants. Wetlands have the capacity to hold large amounts of water and therefore naturally control flooding.
  • Stream Buffers. A stream buffer is a strip of land along each side of a stream that is left in a natural condition. By "natural condition", we mean it is still covered with trees, shrubs, and other vegetation rather than mowed grass or farm crops. Trees and shrubs slow down the speed of flood waters and their roots hold soil in place, therefore protecting the stream banks from erosion. Stream buffers also act as natural filters. For example, buffers located along streams near farms absorb pesticides, fertilizers, and sediment which might have otherwise runoff into streams and reduced the water quality.
  • Natural Open Space. Areas of natural open space have trees, shrubs and other vegetation which allow more rain to soak into the ground. This helps to prevent flood water runoff. The rain water that soaks into the ground recharges ground water supplies. Ground water is what sustains the flow of water in streams during long periods without rain.