1. How to calculate stream order Another way to look at a drainage system is to treat it as a hierarchical network Stream order Stream order increases by 1 each time two streams of the same order join No change in stream order occurs when two streams of different order join Eg a 3 rd order stream receiving a 1 st order stream remains a 3 rd order stream.

2. 1 km x Outline the Watershed of this small tributary to Threepoint Cr. at the point x First study the altitudinal contours Locate the 5000’ 5500’ & the 6000’ Contours What are the highest points in the area How to map a watershed

3. 1 km o o o o o o o Now ask yourself which way would water flow from various points around the creek? The flow path is perpendicular to the contours. The area that delivers water to the point x includes all of the points that flow toward x, and none of the points that flow away from x x

4. 1 km o o o o o o o Start at x, and extend a line up to the east ridge, and follow the ridgetop up to the top of Mt. Barwell, and then extend the line through the saddle and onto the small peak west of the mountain, and along the west ridge back to the point x All points that drain into the creek, and down to point x will be contained within this area, and all points that drain away, should be outside the area x

5. 1 km o o o o o o o x The area of this watershed is 4.5 km 2. What is the avg annual discharge at the point x ? From the runoff map we assign a value of 0.6 m/year 0.6m/yr x 4.5 x 10 6 m 2= 2.7 x 10 6 m 3 /yr =0.1 m 3 /s

6. What are the units of flow measurement? Discharge (R or Q)—L 3 /time Velocity (v)—L/time Discharge can be measured by X-sectional area (L 2 ) of the stream at a point times mean velocity (L/s) Mean depth (L) x width (L) x mean velocity (L/s) If the mean discharge of the creek is 0.1 m 3 /sec, and the mean width at the point “x” is 4 m, and the mean depth is 0.2 m, what is the mean water velocity? V (L/t)=Q (L 3 /t) /(depth (L) * width (L)) V= 0.1 m 3 /sec/(0.2m * 4m) = 0.125 m/sec

7. Q=r*DA As you move down a watershed, the drainage area and discharge both increase x4x4 x3x3 x2x2 x1x1 x1x1 x3x3 x4x4 x2x2 Stream cross-section At x 1 the stream is 1 st order So does the stream order At x 2 the stream is 2 nd order At x 3 the stream is 3 rd order At x 4 the stream is ?

8. 1 st order streams –around 0.01-0.1 m 3 /s Around a 1-2 m wide Drainage area 0.2-1 km 2

9. 2 nd order stream in Quebec and NY Around 0.1 m 3 /sec, 3-4 m wide Drainage area 2-5 km2

10. Storm Creek, a tributary of the Highwood, 2 nd order, around 0.2 m 3 /sec—3-5 m wide Drainage area around 8 km2

11. Johnston Creak above the canyon –3 rd order, around 0.6 m 3 /s—6-9 m wide Drainage area around 25 km 2

12. Highwood River –4 th order, 8 m 3 /s—10-20 m wide DA around 400 km 2

13. Waterton River –5 th order, around 15 m 3 /s—15-25 m wide DA around 600 km 2

14. Oldman River –7 th order, around 40 m 3 /s—50-100 m wide, DA = 17,000 km 2

15. Athabasca R. at Fort McMurray– 8 th order, 2-300 m 3 /s –2-300 m wide, DA 30,000 km 2

16. The Slave River is the largest Alberta River—9 th order, discharge is 1500 m 3 /s, width is over 1km and Drainage Area is 600,000 km 2

17. St.Lawrence River 10 th order Discharge around 10 4 m 3 /s Width 2-3 km DA = 1.2 x 10 6 km 2