A comparison of three visual assessments for riparian and stream health

T. A. Ward; K. W. Tate; E. R. Atwill; D. F. Lile; D. L. Lancaster; N. McDougald; S. Barry; R. S. Ingram; H. A. George; W. Jensen; W. E. Frost; R. Phillips; G. G. Markegard; S. Larson

ABSTRACT:

Visual assessments are integral components of several widely promoted efforts to assess the health of stream and riparian areas across the Nation. The U.S. Environmental Protection Agency's (EPA) Habitat Assessment Field Data Sheet (HAFDS), U.S. Department of Agriculture's Natural Resources Conservation Service's (NRCS) Stream Visual Assessment (SVA), and U.S. Department of Interior (USDI) Bureau of Land Management's (BLM) Proper Functioning Condition (PFC) assessment were applied to 234 rangeland riparian areas to determine: 1) how well the assessments correlate, and 2) how site-specific stream and riparian characteristics affect the outcome of each assessment and thus the comparison of outcomes across stream types. Habitat Assessment Field Data Sheet and Stream Visual Assessment are habitat driven assessments, which target similar parameters resulting in a strong positive correlation between these methods (r = 0.81). BLM's Proper Functioning Condition focuses on parameters related to hydrologic function, thus a weaker correlation was found when comparing Proper Functioning Condition to the Habitat Assessment Field Data Sheet and the NRCS' Stream Visual Assessment methods (r = 0.58 and 0.54, respectively). A combination of one habitat assessment and Proper Functioning Condition should be utilized to conduct a comprehensive assessment of riparian/stream health. Site characteristics, which were significantly associated with assessment outcomes included entrenchment ratio, substrate size, channel width to depth and slope. This presents a problem in that comparison of assessment outcomes across different streams and stream reaches are confounded by factors such as slope and substrate type, which may not always be indicative of riparian/stream health. The Rusgen Stream Morphology Classification system was used to successfully control for the effect of these site-specific effects on assessment outcome, allowing for comparison of riparian/stream health assessments across streams.

Footnotes

Theresa A. Ward is a livestock/natural resource advisor with the Stanislaus/San Joaquin Counties University of California Cooperative Extension in Modesto, California. Kenneth W. Tate is an extension rangeland watershed specialist in the Department of Agronomy and Range Science at the University of California, in Davis, California. Edward R. Atwill is an associate veterinarian and associate specialist in the Department of Population Health and Reproduction at the University of California, in Tulare, California. David F. Lile is a livestock/natural resource advisor with the Lassen County University of California Cooperative Extension in Susanville, California. Don L. Lancaster is an extension advisor with the Modoc County University of California Cooperative in Alturas, California. Neil McDougald is a livestock/natural resource advisor with the Madera/Fresno Counties University of California County Cooperative Extension in Madera California. Sheila Barry is a Bay Area natural resource advisor with the University of California Cooperative Extension in San Jose, California. Roger S. Ingram is a livestock/natural resource advisor with the Nevada/Placer Counties University of California Cooperative Extension in Auburn, California. Holly A. George is a livestock/natural resource advisor with the Plumas/Sierra Counties University of California Cooperative Extension in Quincy, California. Wayne Jensen is a livestock/natural resource advisor with the San Luis Obispo/Santa Barbara Counties University of California Cooperative Extension in Santa Maria, California. William E. Frost is a livestock/natural resource advisor with the El Dorado County University of California Cooperative Extension in Placerville, California. Ralph Phillips is a livestock/natural resource advisor with the Kern County University of California Cooperative Extension in Bakersfield, California. Gary G. Markegard is a livestock/natural resource advisor with the Humboldt/Del Norte Counties University of California Cooperative Extension in Eureka, California. Stephanie Larson is a livestock/natural resource advisor with the Sonoma/Marin Counties University of California Cooperative Extension in Santa Rosa, California.
Copyright 2003 by the Soil and Water Conservation Society

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