Water Cycle - Marcom Projects

48
Script
a. water molecules rise into the air
b. water vapor condenses into liquid droplets
c. water droplets become too heavy and fall to the ground
d. plants release water into the atmosphere
Well, maties, you handled that like life-long boat lovers! As long as you
give me your answer, you can be my first mate anytime.
SCENE FOUR
PROFESSOR SCIENCE
Welcome back! It’s time to take a little journey with water. Here we go!
The basic water cycle, evaporation, condensation and precipitation, seems pretty
simple. But water has a lot of functions on Earth, as well. As I was saying earlier,
not all water evaporates immediately after it falls to the ground. Although 97%
of all water is in the oceans, water travels on land, too, both above and below
the ground. Only one-half percent of all water exists underground, but that’s 25
times more than what flows in our rivers and lakes. Wow! There’s a lot of water
in the ground.
Remember how we talked about the properties of water? Well, ground water is
usually in liquid form, except in arctic regions. If evaporation doesn’t occur, the
force of gravity pulls water down, toward the center of Earth, through the path
of least resistance.
A number of factors determine the path of precipitation after it falls to the
ground: the slope of the land, the amount of vegetation on the surface;
the level of ground saturation, the amount and rate of rainfall, and the
permeability of the ground.
For example, if rain comes down on the side of a mountain that is rocky and
steep, most of it will run down hill. This is called runoff. It doesn’t absorb
easily into the ground, so it moves on. Further down the hill, the slope gets
gentler, which slows the runoff down. Even further down the hill are trees
and vegetation. These factors hold the runoff back even more.
Some of the water that started at the top of the hill will reach ground that
is permeable. That means liquid can flow through it. Sometimes that ground
may already be saturated, or full of water. When this happens, the runoff
continues to make its way to lower ground and streams or rivers. So, you
Water Cycle Video Quiz © Sunburst Visual Media, a division of Global Video, LLC