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Presentation on theme: "Watersheds."— Presentation transcript:

1 Watersheds

2 Surface Water Definition: fresh water on the Earth’s land surface
Is found in lakes, rivers, streams, and wetlands Types of surface waters are: River systems Mississippi, Amazon, Nile Watersheds Definition: area of land that is drained by a river Example: Mississippi Watershed


4 A Watershed Definition - The total land that contributes water (or drains into) a particular waterway. Can also be called a "Drainage Basin" A watershed is the total land that contributes water or drains into a particular waterway Watersheds are sometimes referred to as drainage basins because water in this area is draining into a body of water

5 A Watershed All of the water within the area drains into the central waterway and to a specific point along that waterway. It is important to realize that a watershed is composed of not only a waterway itself (stream, creek, river, lake) but also the surrounding land area that drains into it. In this illustration, all the water within the green region drains into the central waterway and actually to a specific point at the end (or the mouth) of this creek.

6 Watershed or Drainage Basin
The drain board under a kitchen sink drying rack is like a watershed. The "Dry Dish" Watershed If it helps, you can think of a watershed as a dish drying rack drain board next to your kitchen sink. All the water dripping of your plates is eventually funneled out of the drain board and into your sink.

7 All three interact with each other!
Go with the Flow Water always follows the path of least resistance DOWNHILL! Water that flows through a Watershed: -Streams, Creeks, and Rivers -Surface runoff (water across the land surface) -Groundwater (under the surface) All three interact with each other! Water is lazy. It always wants to flow down hill because of gravity. It is too much work to flow uphill, so it doesn’t. Water flows down hill, the path of least resistance Water that flows downhill through a watershed includes: 1. Streams, creeks or rivers 2. Surface runoff (water across the land surface) 3. Groundwater (moving under the surface, under our feet)

8 Flow: Streams and Rivers
So streams and rivers are part of a watershed, part of the downhill flow of a watershed

9 Includes over forested land, grassland, and parking lots
Flow: Surface Runoff Surface Runoff can also be called Overland Flow Includes over forested land, grassland, and parking lots Surface runoff, which can also be called overland flow, is moving, amazingly enough, over the land surface. It may be flowing over a forested surface, a cropland surface, or even an urban, cement-like surface.

10 Under the surface Groundwater is on the move
Flow: Groundwater Under the surface Groundwater is on the move Groundwater is another important flow in a watershed. Sometimes it is forgotten about because we cannot see it, or some people don’t know that it exists. Did you realize that there is water always under our land surface, under our feet, collecting and/or moving?

11 Fuel for the Flow: The Water Cycle
The Water Cycle provides the water to create these three types of flow. What provides all of this water (whether on the surface or underground) to our watershed? You might remember the water cycle. Water evaporates from the surface, condensation occurs forming clouds that precipitate down, providing us the “fuel” for our flows through the watershed. (Point out the direction of flow of water through the cycle, showing various possible routes.) So there is a real connection between the water cycle and a watershed.

12 (Shape of the lands surface)
Watersheds Land Area TOPOGRAPHY (Shape of the lands surface) Determines what area will make up a watershed The rain from our water cycle falls down onto the land. This land and the shape of the land surface, called topography, play an important role in creating a watershed.

13 Watershed Topography Low points in a watershed:
Stream or river itself, the very bottom There are low points (lower elevations) in a watershed. This is the stream, creek, or river itself, and the ravine or valley bottom.

14 Watershed Topography Highpoints in a watershed:
Hills, Mountains, or ridges surrounding the waterway. There are high points (higher elevation) in a watershed. These are hills, hilltops, or mountains that surround the waterway. In Western Pennsylvania, our higher elevations are hills, but there are mountains further east.

15 Watershed Boundary The watershed boundary is created by the high points of land surrounding a waterway Watershed Boundary These high points of land help create a watershed boundary. The boundary is the extent of the land area surrounding our waterway that drains into our creek. Once you cross the boundary, water would no longer drain into our waterway. Hills and ridges would make up a part of our watershed boundary. (On the illustrations, point out the land area that is part of the watershed leading up to the hills and higher elevations that make the watershed boundary)

16 Watershed Boundary Any water within the boundary of your watershed or precipitation that falls within the boundary will flow into your waterway Within a watershed boundary, all of the water, whether surface flow, surface runoff, groundwater, or rain will eventually flow into our creek. (On the visual illustration, point out how water inside the ---boundary line would drain into this main waterway)

17 Watershed Boundary Any water OUTSIDE the boundary of your watershed or precipitation that falls OUTSIDE the boundary will flow into a different waterway is part of a different watershed. Now if some of the water falls outside our creek’s watershed boundary, it is not part of our watershed because it does not flow into our creek. But it is part of an adjacent watershed. It is falling on land that is draining into a different creek. (Use illustration). See how the two watersheds are beside each other on this illustration?

18 Watershed Boundary The watershed boundary is the dividing line between two watersheds Watershed boundaries are sometimes called Watershed Divides So the boundary is the place where rainfall must decide which direction it is going to flow – toward our creek or toward a different waterway. The boundary is the dividing point. And remember, the boundary is a high point of land.

19 Many Watersheds Does your favorite stream have a watershed?
Does your favorite creek have a watershed? (Ask some students) All waterways, large or small, have a watershed. Waterways always have land surrounding them that drain into them. Small creek=Small watershed Large Creek=Larger Watershed

20 Build up a Waterway waterways flow into one another.
small creeks flow into Large creeks which flow into LARGER creeks or a river! As you might realize, waterways flow into one another. Small streams join together to form bigger creeks, which can flow together to form even larger waterways.

21 Build up a Watershed Even LARGER Watersheds
Watersheds interact with one another too. Small watersheds make up Larger Watersheds which make up Even LARGER Watersheds Just as waterways join together and build up, watersheds also interact with each other. Small watersheds make up larger watersheds, which will be part of even larger watersheds.

22 Scale Watersheds work on different scales
small creeks have small watersheds large creeks include the watersheds of many small creeks rivers include the combined watersheds of many large creeks Allegheny River French Creek Watersheds are all a matter of scale. As mentioned earlier, small creeks have small watersheds. Like Sugar Creek. [CLICK] Small watersheds, like Sugar Creek, make up larger watersheds, like French Creek. French Creek is part of the larger Allegheny River Watershed. The Allegheny River Watershed has other smaller creeks (and their smaller watersheds) that are part of it. Sugar Creek

23 No Watersheds Somewhere?
Is there any place on land that is not part of a watershed? No, Everywhere you stand on the Earth's land surface drains somewhere, so it is part of a watershed, whether big or small. Is there a place on land that is NOT part of a watershed? [CLICK] NO. Everywhere you stand on the Earth’s land surface drains somewhere, so it is part of a watershed, whether big or small.

24 What is YOUR Watershed? Small watershed? Big watershed?
Where does your water flow to? Which of the major watersheds in Costa Rica are you in? What is our watershed here at school? Is it a small watershed? Large watershed? Where does our water flow? Which of the major watersheds contain our local waterways? (you would need to personalize this discussion based on your location) [CLICK]

25 Watershed Impacts Our Water Cycle The Fuel that Runs the Watershed
Now, let us consider some of the things that might make an impact on our watershed. First off, we learned that the water cycle plays a role in a watershed by providing the “fuel” of the flow through the watershed. So it makes an impact. [CLICK]

26 Watershed Impacts (Rural)
Land and waterway interaction Because rain and snow falls on the land and eventually flows into our waterways, there is an interaction between the land and our waterways. What we do on our land makes an impact on water quality. [CLICK] For instance, we might have a farm in out watershed. What impacts might this have on the waterway? (students answer) (some possible answers: maybe the cropland will have some soil erosion or there have been some chemicals, pesticides, herbicides used on the fields. Maybe some fertilizer washes into the nearby creek. Livestock might cause soil erosion or break down stream banks trying to get into the creek. Their waste might wash into the creek. What we do on our land affects our waterways

27 Watershed Impacts (Urban)
Land and waterway interaction What if we had a factory or industry? What impacts could that make? [CLICK] Some possible answers: maybe the industry discharges chemicals or toxin directly into the creek or onto the land next to the creek. The discharge could also be high in nutrients or organic waste or just be warm water that was a byproduct of an industrial process (such as a cooling process). Keep in mind that the possible pollution does not have to be added directly to the creek. If the land around the creek is polluted, that will still make an impact on the waterway because of how a watershed drains. What we do on our land affects our waterways

28 Watershed Impacts (Residential)
Land and waterway interaction What impact do you have on the watershed? Maybe at your house? [CLICK] Some possible answers: maybe you put too much fertilizer or herbicide chemicals on your front lawn and this seeps down into the groundwater. Maybe you pour inappropriate things down the storm drains/grates on the street or onto your land (like old car oil, antifreeze, old paint). If you live in the country, maybe your septic system is not functioning properly. What we do on our land affects our waterways

29 Watershed Impacts We influence our waterway and watershed
Direct Impact on Waterway Dumping into creek, littering into creek Impact on Land Surrounding Waterway (Watershed) Poor land use decisions Disturbing the land without minimal impact Contributing to pollution on the land So we do influence our waterways and watersheds. Perhaps directly by dumping something into the creek or littering into the creek. Or by making an impact on the land that drains into the waterway (watershed.) We might make poor land use decisions or disturb the land without regards to making a minimal impact on it, or by contributing to pollution we put on or into the land. [CLICK]

30 Watershed Impacts Downstream
We are connected to others downstream Our waterway flows into other waterways Our watershed drains into other watersheds Our mess/pollution travels downstream Also remember a very important point – that the watershed that we live in is connected to other watersheds downstream. So what we do here may influence another waterway or people further downstream. Our pollution becomes their pollution. Our impact might be detected miles and miles away. [CLICK]

31 Watershed Impacts What will YOU do to protect your watershed?
So with all of this watershed knowledge, what might you do to help protect your watersheds? Or what could your school, to help protect its watershed? There are many possibilities, but here are a few: We could study our stream, monitor it, determine its health, and keep an eye on its water quality. Perhaps do things to improve our stream like plant trees along its bank. Or other stream restoration projects, improving the water quality and habitats. Or something like storm drain stenciling in our community to encourage people not to pollute. Or educating our community about our waterways and what we have learned about them. Or sponsoring or participating in a creek clean up event. [CLICK]

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