1. Watersheds
ESI
ESI

2. A map of streams in an area
Can you determine the watershed for this stream?

3. N Major stream in watershed Drainage divide high spot or ridgeB
What is general streamflow direction? Any water flowing north?
Cross-section

4. B A Cross-section Drainage Divide Runoff to the west
Runoff to the east
Looking north up ridge B A
Cross-section

5. Major streams in watershed
headwaters
Watershed boundary
headwaters
Tributary to major stream
mouth
main channel
mouth

6. Stream Gradient Water flows downhill ! headwaters Drop in elevation
-Idiot’s Guide to Stream Hydrology
Drop in elevation
mouth
Distance traveled
Stream Gradient =
Drop in elevation, feet
Distance traveled, miles
(average)
Typical stream gradient in Prince George’s County – xxx ft/mi

7. N
Area of collection of precipitation

8. Steps in the hydrologic cycle
precipitation
runoff and stream – surface flow
evaporation
transpiration
infiltration
groundwater (subsurface) flow
evapotranpiration

9. runoff
precipitation
transpiration
evaporation
infiltration
groundwater

10. N
Watershed
subwatershed
Even smaller subwatershed

11. Nested watersheds airshed watershed Watershed is like a funnel
Container such as Chesapeake Bay

12. Watershed and Airshed of Chesapeake Bay

14. Maryland’s Watersheds
To the Delaware Bay watershed
To the Mississippi River Watershed
East coast continent divide
95% of Maryland
drains water into
the Chesapeake Bay
To the Atlantic Ocean directly

15. Prince George’s County
Potomac River
Watershed
Patuxent River
Watershed
Drainage Divide in
Prince George’s County