Headwater streams – what are they and what do they do? Ken Fritz and Brent Johnson Photo image area measures 2” H x 6.93” W and can be masked by a collage strip of one, two or three images. The photo image area is located 3.19” from left and 3.81” from top of page. Each image used in collage should be reduced or cropped to a maximum of 2” high, stroked with a 1.5 pt white frame and positioned edge-to-edge with accompanying images. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Office of Research and Development National Exposure Research Laboratory, Ecological Exposure Research Division May 24, 2011 Outline of presentation • What are headwater streams? - Where are they? - CtfhdtComponents of headwater catchments - Longitudinal transitions • Hydrology of headwater streams - Major flowpaths - Expansion – contraction - How to characterize permanence • Headwater stream functions - Struc ture and functi on - What are the vitals and how to measure them 1 What are headwater streams? • Subjective term for a small tributary – depends on context and scale • Tributaries are permanent longg(itudinal features (bed Bank & banks) where water & Streambed Bank associated materials from surface runoff and/or ground water are concentrated & mixed at the land-atmosphere 2 interface. Stream classification • Exterior or most upland tributaries in river networks • Typically considered to be 1st & 2nd order streams, but depends on map stream order link magnitude 11 11 11 11 2 2 2 1 2 1 3 1 1 5 2 1 2 1 3 3 7 Extent of headwater streams headwaters: 94.9% of streams & 73.2% of total length Stream number sed) 1500000 Total l en gth oo Average length 1500 i) total miles (cl miles total 1000000 mm 1000 r (open) and age length ( ee rr 500000 Ave 500 Stream numb 0 0 1 2468103 5 7 9 Order 4 (from Leopold et al. 1964) Headwater streams: a national picture Headwater Stream Length as a Percentage of Total Stream Length % Headwater Streams 0 1-19 20 -36 37-48 49-57 58-100 State boundary 5 (from Nadeau and Rains 2007) Map scale & headwater streams 1:100K 1:24K C – 1st B – 2nd A – 3rd C # 1st = 5 B A C – 0 st B – 1 C A – 2nd B 1 km 1 km # 1st = 2 A 1:15.8K cC C – 2nd Bb B – 3rd A th 6 a –4 A 0.8 km # 1st = 41 Extent of headwater streams National Field surveyyging the p osition Hydrographic of channel origins & Database (NHD) total stream hydrologic transition zones length : 233 km Estimate extent of headwater streams within surrounding HUC based on field determined Flow Generated Accumulation Coefficients. prediction total stream length: Comparisons to existing 527 km resource databases. 7 NHD coming up short? Location HUC drainage Total stream length (km) Percent area (km2) NHD Generated additional 124K1:24 K lthlength Robinson Forest, KY 7.5 12 28 +133.3 Wayne N.F., OH 45.4 17 49 +188.2 Dodge Brook,NH, NH 76.3 151 317 +109.9 Edge of Appalachia, OH 77.5 2 28 +1300.0 Hoosier N.F., IN 91.4 39 49 +25.6 Lower Big Sandy, WV 104.3 114 299 +162.3 Shawnee N.F., IL 128. 7 233 527 +125. 9 Silver Creek, WA 131.4 242 511 +111.4 Cheat River, WV 158.4 179 454 +153.6 Huntingg,ton River, VT 172.3 276 508 +84.1 Beaverkill, NY 251.3 255 481 +88.8 Fir Brook, NY 342.8 438 701 +60.0 n = 12 X = +114.4 8 Headwater catchment components A B C Transitional channel A – valley head or swale B – gradual channel head C – abrupt channel head 9 (based on Dietrich & Dunne 1993) A longitudinal tour 10 Drainage area: 1.9 ha Slope: 46.3% D50: 128 mm (cobble-boulder) Steep sideslopes Colluvial/cascade 11 Drainage area: 9.6 ha Slope: 9% D50: 64 mm (pebble-cobble) Steep sideslopes Cascade/step-pool 12 Drainage area: 18.5 ha Slope: 3.3% D50: 64 mm (pebble-cobble) Less constrained Riffle-pool 13 Drainage area: 89.4 ha Slope: 2.3% D50: 64 mm (pebble-cobble) Unconstrained Riffle-pool 14 Precipitation Hydrologic flowpaths Soils Overland flow Bedrock Evapotranspiration Deep groundwater recharge and flow V Channel Hyporheic exchange Alluvi um 15 Transmission Expansion-contraction Gray = ground water contributing zone Perennial Intermittent Ephemeral Seep spring Isolated wetland Adjacent wetland 16 Expansion-contraction Hydrograph mapped w/ extent of flowing channel. Southwestern British Columbia, drainage area : 300 ha (~1 mi2) 17 (from Cheng 1988) Hydrologic Permanence • Ephemeral, intermittent & perennial • But permanence varies continuously (rather than categorically) in frequency, duration & timing • Interannual variation • Longitudinal gradient, but can be discontinuous over space • Surface and subsurface • Direct and indirect methods to chtiharacterize 18 Electrical resistance data (168.3 ha) (46.7 ha) 3 (18.6 ha) (8. 1 ha) 19 Structural Measures of Stream Condition Canopy cover Woody debris Geomorphology Pools Riparian vegetation Streambed particle Algal RBPs size biomass Current velocity Riffles Invertebrate diversity Salamander abundance Functional Measures of Stream Condition Leaf decomposition Organic matter input Organic matter retention Energy management Colonization Hydrologic exchange Benthic metabolism Primary production Nutrient uptake Secondary production Orggpanic matter export Sediment retention What do Appalachian headwater std?treams do? Intimately linked to hillslopes Represent sources to the network • Supply water • Store, transform and transport organic matter/energy (metabolism & production) • Store and transport sediment • Store, transform & transport nutrients • Buffer water temperature Not necessarilyyy continuously Cumulatively over time & space 22 How to measure the vitals? 23 Acknowledgements David Walters Allison Roy Karen Blocksom MiPMaggie Passmore Greg Pond Jim Wigington Stephanie Fulton Roger Burke Chris Barton Jeff Jack David Word VT Stream T eam 24.