1. Watersheds as Integrators of Climate: The Hydrogeomorphic Template as
Fundamental Construct?

2. hydroclimatology & flow regimes
watersheds as integrators
6 degrees of connection
hydroclimatology & flow regimes
rainfall, snowmelt, rain-on-snow, mixed runoff
implications for flow regime
hydrogeomorphology
interactions among flow, sediment & substrate

3. Watersheds as integrators
proximal: 6 degrees of connection

4. upstream- downstream migratory fish drift of larval insects
nutrient flow
water discharge
sediment movement
plant propagules
contaminants
Grand Canyon

5. atmosphere- channel atmospheric deposition PAHs, VOCs, N, Hg
wind-blown sediment
insects
atmosphere-
channel

6. hillslope- channel hillslope sediment wood nutrients, contaminants
Nepal
hillslope-
channel

7. floodplain-channel organic matter contaminants sediment water
Amazon River
organic matter
contaminants
sediment
water
fish, amphibians, reptiles
floodplain-channel

8. hyporheic-channel groundwater-channel larval aquatic insects
contaminants
sediment
water
nutrients & minerals
water
dissolved contaminants
nutrients & minerals
hyporheic-channel
groundwater-channel

9. Rocky Mountain National Park, Colorado

10. precipitation temperature
Climate
precipitation temperature
bedrock weathering
sediment
infiltration/runoff
vegetation
solutes (nutrients)
The big picture
Geology
energy (tectonic)
topography (gradient)
substrate resistance

11. Hydroclimatology & flow regimes
rainfall – convective, cyclonic, (orographic)
magnitude, duration, intensity, spatial extent, recurrence
snowmelt
depth, water content, rate of melt
mixed runoff sources
mixed populations for statistical analysis
(non-stationarity)

12. Runoff + Basin Characteristics = Flow Regime
drainage area
shape of drainage basin
relief ratio
drainage density
valley geometry

13. Characterizing the Flow Regime
intra-annual variability
peak flow/base flow
flashiness
magnitude, volume, duration, frequency of peaks
rate of rise & recession
inter-annual variability
+ basin characteristics =
geomorphically & ecologically relevant characteristics
Overall flow variability, extent of intermittency, predictability of flow
(Poff & Ward, 1989; Poff & Allan, 1995; Poff, 1996)

15. Geomorphically & Ecologically Relevant Characteristics
Water & sediment connectivity (extent, duration, magnitude)
(e.g., flood pulse – productivity, dispersal, habitat, predation)
Hydraulic force/substrate resistance
bedrock erosion threshold
Unit stream power (W/m2)
alluvial erosion threshold
Riverine vs hydrologic connectivity
Time
Habitat abundance, diversity, stability

16. Hydrogeomorphic template
reflects interactions among flow, sediment & substrate
flow
sediment
substrate
habitat channel process
(abundance, diversity, stability/disturbance) & form
dispersal
food

17. The Natural Flow Regime
beyond minimum flow
magnitude, frequency, duration, timing, rate of change
flow as physical driver (NFR organizes & defines river ecosystems)
What next?
IHA (quantify flow regime changes)
(monthly average magnitude; magnitude, duration & timing of annual extreme
conditions; frequency & duration of high & low pulses; rate & frequency
of change in flow)
response curves (quantify physical & ecological responses to flow)