Pacific Southwest Research Station , Fresno, CA

Kings River Experimental Watersheds

KREW

2012 Accomplishments Snowmelt runoff and water yield along elevation

and temperature gradients in California’s southern Sierra Nevada Journal of the American Water Resources Association

Sediment loads and erosion in forest headwater streams of the Sierra Nevada, California. IN A.A. Webb, et al. Revisiting Experimental Catchment

Studies in Forest Hydrology, IAHS Press

Controls of streamflow generation in small catchments across the snow-rain transition in the Southern Sierra Nevada, California Hydrological Processes

Goals of the KREWExperimental Watersheds

Understand processes and quantify variability of headwater stream ecosystems

Evaluate the effects of forest management for healthy forests Prescribed fire Thinning

Apply models

Integrated Watershed Research Hydrology Meteorology Air quality Sediment &

turbidity Soils &

geomorphology Water chemistry Biology

Stream macroinvertebrates

Algae Riparian & upland

vegetation Yosemite toad

What is the current/natural variability in headwater streams and their associated watershed characteristics ?

Why is this important ?

To evaluate the effects from Changing climate Forest management

Stream Discharge Patterns and Sediment Loads

Streamcode

Area(ha)

Sediment LoadAverage annual

(2003-2009)Stream banks(2005-2006)

Headcuts(2003-2005)

Headcuts(2003-2009)

Normalized weight

kg/ha ± s.d.

Volume(m3)

Volumeeroded (m3)

per year

Volumeeroded (m3)in 2 years

Volumeeroded (m3)In 6 years

P301 99 6 ± 8 0.6 10.0 4.2 (2.1/yr)

P303 132 2 ± 3 0.3 20.9 3.3 (1.6/yr)

P304 49 61 ± 61 3.0 1.4 1.6 (0.8/yr) 18.6 (3.1/yr)

D102 121 17 ± 20 2.1 23.6 2.3 (1.2/yr)

B201 53 13 ± 14 0.7 

B203 138 10 ± 12 1.4 

B204 167 8 ± 11 1.4 

T003 228 16 ± 21 3.6 

Controls of Streamflow Generation

Endmembers identified from mixing models using Ca, Mg, K and Cl

Streamflow components 60% subsurface flow < 40% snowmelt runoff < 6% fall storm runoff

Not significant Regional groundwater and soil water in

unsaturated zone

Regional groundwater and soil water in unsaturated zone

Mixed-Bed Resin Lysimeters at KREW 2 soil & 1 throughfall every 150 m

NO3 & NH4 annual fluxes

Values at Nearby Sites

Site Elevation(m)

Annual N Loading

kg/(ha*yr)

O3 24-hr Average(ppbv)

Emerald Lake 2,800 2 – 5 56 - 61

Mountain Home State Park

1,890 17 71

Giant Forest 1,920 6 – 12 66

KREW 1,600 -2,100

2003 142004 9

2-week integrated

37 -87

Ozone 40 ppb background level60 ppb elevated level

N Deposition Levels in 2008

NH4 Flux to Mineral SoilExtreme Values

KREW Timeline

2000 started building experimental site

WY 2003 data collection started 2005-2006 added sites &

instruments 2007 SSCZO started 2012 thin 2013-2014 understory burns

Latest burn spring/summer 2014 2017 2nd burn ?