1. How do humans affect watersheds, the hydrologic cycle and stream ecology? AKA management implications

2. Human caused disturbances?

3. Human caused disturbances
Agriculture
Timber harvest
Mining
Urbanization
Introduction of exotic species
Harvesting of fish and wildlife
Fire suppression

4. Land Use and Vegetation
Agriculture: tree removal and replacement with pasture or crops
andrebaertschi.photoshelter.com
dailyinfo.co.uk

5. Land Use and Vegetation
Forestry: tree removal and replacement over time

6. Land Use and Vegetation
Mining: extent of vegetation alteration depends on type of mining
Acid mine drainage
Underground gold mine Wales
West Va Photo credit: Kent Kessinger
/acid_mine_drainage_2.jpg

7. Land Use and Vegetation
Urbanization: tree removal and replacement with grass and impervious surfaces .
Lake Union
Samish Lake

8. Aggregate Mining In-channel mining Floodplain mining
Sediment transport interrupted
Produces local sediment deficit
Can lead to increase accumulation
of fines and blocking of sediments
Incision can lower the water table
Floodplain mining
Can lead to loss of groundwater storage
Can affect hyporheic zone
Reduce summer base flow
Slide show gravel mining.
Photos by M. Kondolf

9. Landscape controls Physiography, e.g., Climate, e.g., Land use/cover
topography, soils,
aspect
Climate, e.g.,
temperature, humidity
precipitation, wind
Land use/cover
and vegetation
Gross reach
morphology
Habitat Forming
Processes
Solar energy
and
Organic input
Regime
Nutrient
Inputs
Sediment
and Hydrologic
Regime
Stream
Morphology and
Conditions
Slide depicts the interaction among landscape controls, habitat forming processes, stream morphology and biodiversity. Gray boxes at the landscape control level indicate things that humans have little to no control over.
Habitat complexes and conditions
e.g., pools, riffles, temperature, etc.
Biodiversity
Species assemblages
Modified from Roni et al

10. Effects of vegetation removal on hydrology and streams
Precipitation ?

11. Effects of vegetation removal on hydrology and streams
Precipitation ?
Evapotranspiration ?

12. Effects of vegetation removal on hydrology and streams
Precipitation ?
Evapotranspiration
Infiltration ?

13. Effects of vegetation removal on hydrology and streams
Precipitation ?
Evapotranspiration
Infiltration
Surface runoff ? Subsurface runoff ?

14. Effects of vegetation removal on hydrology and streams
Precipitation ?
Evapotranspiration
Infiltration
Surface runoff Subsurface runoff
Frequency and magnitude of
peak flows ?

15. Effects of vegetation removal on hydrology and streams
Precipitation ?
Evapotranspiration
Infiltration
Surface runoff Subsurface runoff
Frequency, magnitude and timing of
peak flows
Materials transported to stream ?

16. Effects of vegetation removal on hydrology and streams
Evapotranspiration
Infiltration
Surface runoff Subsurface runoff
Frequency and magnitude of
peak flows
Materials transported to stream

17. Urbanization What do all these human activities have in common?
Agriculture
Slide showing pictures of forest harvest.
Forestry
Mining

18. Forestry, agriculture and urbanization
Remove trees and other vegetation
Alter natural organic matter and nutrient delivery
Build roads, culverts, ditches

19. Precipitation
Natural
Developed
Rapid flow limited storage
Slow flow
Pollutant wash off
Natural cleaning
Large storage in soil, channel and valley floor
Reduced soil storage
Limited infiltration
No recharge
Recharge

20. Floods and Urbanization
surface runoff vs. infiltration
natural land cover vs. urban area

21. Drainage Density Low peak, gradual rise Higher peak, quicker rise
Channels
Roads,
Ditches,
Drains
Lower drainage density P P
Higher drainage
density
Slide showing effects of drainage density on flooding. Q Q
time
time
Low peak, gradual rise
and fall
Higher peak, quicker rise
and fall

22. Biological Indicators - Invertebrates
Nutrient Cycle. Invertebrates play a crucial role in the stream nutrient cycle.
Pollution Tolerance. Some insects are tolerant of pollution, whereas others are not. For example, the order Plecoptera (Stoneflies) are very sensitive to pollution
Population Fluctuations. Because many insect life cycles are short (sometimes one season in length), we can detect population fluctuations in a short period of time

23. Benthic Index of Biological Integrity, or B-IBI
Composed of 10 metrics
Total richness (# of different species)
EPT richness (mayfly, stonefly, caddis fly)
Ephemeroptera, Plecoptera, Trichoptera
Intolerant richness
Clinger richness
Long-lived richness
% tolerant
% predator
% dominant

24. How do we manage watershed?
Dept of Natural Resources Regulations
U.S. Forest Service Regulations
Clean Water Act
Endangered Species Act
Total Maximum Daily Loads (TMDLs)

26. Washington Water Types
Shorelines and large rivers
Type F
Rivers and associated wetlands, lakes, ponds, etc. > 0.5 acres at seasonal low level and have FISH
Type Np
Perennial streams without fish
Type Ns
All other streams not included above- seasonally dry streams without fish

28. Regulations a function of water type and forest site class
Core: No harvest or construction except for permitted road activities
Inner Zone: Harvest allowed but must meet future desired conditions standards (140 yrs)
Width depends on stream size and site class
Outer Zone: Must leave 20 conifer trees per acre > 12 inched dbh

30. Homework reminders Velocity meter method:
Do NOT take the average velocity of your flow meter measurements and multiply by cross-sectional area to get discharge Q. The velocity meter method involves summing the delta Qs to get the total Q.
That is, as your diagrams indicate, each place you took a velocity measurement is the center of a small area of the stream cross-section. As the spreadsheet indicates, compute Q for each small area and then sum all the Qs to get the total Discharge for the stream.

31. Velocity – Area method of discharge measurement
Tape measure- horizontal location of measures taken from tape
Water surface
Measurement represents mid-section of a polygon
Velocity measured 0.6d from water surface (0.4d from bottom)
Record x value (tape distance), y value (total depth at measurement
site, and velocity at 0.6d

32. Mid-point method of calculating discharge (Q)
Location of depth and velocity measurements
Area included
Area not included
Key Assumption: Over estimation (area included) = Under estimation (area not included), therefore cross-section area is simply the sum of all the sections (rectangles), which is much easier than taking the integral! However, the hypotenuse of each over-under estimation triangle can be used to calculate the wetted perimeter.

33. Y X V Tape reading excel excel excel excel W=(12-9)/2 W=(20-18)/2 Sum
Multiply
Sum
W=(12-9)/2
W=(20-18)/2
W=( )/2
Tape
reading
excel
excel
excel
excel Y X V

34. Homework reminders Float method:
Sum the delta areas from your velocity meter method to get the cross-sectional area of flow
Remember Q (discharge) = cross-sectional area X velocity
Q units are volume/time (cubic feet per second)
Area units are feet squared
Velocity units are ft per second
Needs a correction factor to account for the fact that surface velocity is not equal to average subsurface velocity

35. Take Home Messages
Understand the interactions between land use/land cover and components of the hydrologic cycle
Be able to describe what is typically measured in watersheds and why
Be aware of Washington stream types and how they are used in management
Know 2 methods for computing stream discharge