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Setting out from Grand Mountain
The journey with our river molecules begins one warm April morning high on Grand Mountain. The energy from the sun's rays melts the snow and frees the molecules to trickle into the valley below and join Eco River.
Some of these molecules have been down Eco River before. They know that sections of the journey ahead may be perilous. There will be many side trips – they will be taken into water and wastewater treatment facilities, into farmers' irrigation systems, become part of industrial waste, travel through narrow pipes and sewers, and wash over many of your bodies. Some will be drawn into the atmosphere and be carried by winds to other parts of the earth. This might not be an easy ride.
On the other hand, there will be peaceful and uneventful cruises through wilderness areas, parks and other protected regions – places where they can count on no pollutants from humans being dumped among them, they will not be dragged through pipes, and they will flow close to wild animals and plants by the shores.
A number of molecules will not make it all the way to the ocean this trip – they will seep downward from the earth's surface to become part of the groundwater, or they will evaporate into the atmosphere. Either way, they remain part of the water cycle, or hydrologic cycle, which has been in constant motion since the earth was formed.
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Investigate your local environment
How familiar are you with weather patterns in your area? Why do areas near mountain ranges get more rainfall than flatlands?
How does the precipitation in your area compare with other regions in your province or territory? Compare the precipitation in your province with other provinces or territories.
Record the precipitation in your local region over a two-week period. Check with Environment Canada weather offices, newspapers, weather forecasts. What is the average rainfall? What was the record for most/least rainfall?
The amount of rainfall which falls in a region quite often depends upon the location of geographical landforms like mountains. Is this a factor where you live? Draw a map of your area explaining why you get the weather you do.
Weather patterns affect the kinds of plants and animals which inhabit a region. What kinds of plants and wildlife are native to your area?
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All the rivers run into the sea... Why don't the oceans overflow?
When we think about the water cycle, we often forget the importance of the atmosphere and the role it plays in distributing water around the earth. The water molecules which travel with the river from the mountain to the ocean had to get to the mountain some way. They did not travel up the river because water does not flow uphill.
Study the diagram of the water cycle and note the number of functions which occur in the atmosphere – and don't forget the winds which carry clouds all around the earth. Now, explain in your own words the story of one water molecule's journey to the top of the mountain.
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DID YOU KNOW?
World Water Budget
There are approximately 1.4 billion cubic kilometres of water on our planet, it is stored as: surface water (oceans, rivers, lakes, snow, glacier); water in the atmosphere; and water underground (groundwater). Unfortunately, almost all of the water is unavailable for drinking purposes. Of the world's total water supply, 97.47% is salt water and 2.53% is fresh water, some of which is stored as ice. Only a small fraction of this amount, 0.01%, is available for meeting our fresh water needs, and is found in rivers, lakes, in the ground and in the atmosphere.
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The water cycle
Water is always in motion, constantly circulating from the atmosphere to the earth and back again to the atmosphere. This unending process is called the hydrologic or water cycle. There is no starting point or end point to the cycle because water changes form but does not disappear. For example, water molecules can fall as precipitation, then be carried to the sea by rivers and groundwater before being transferred back to the atmosphere by transpiration and evaporation. Water in the cycle can move through three different forms – as a liquid, solid, and vapour. The energy that causes the water to change form, and so continue the cycle, comes from the sun.
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