Streambank Alteration

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Using Multiple Indicator Monitoring Protocols. Streambank Alteration. What is MIM Streambank Alteration?. The number of lines on the plot that intercept hoof prints, hoof shears – disturbances caused by trampling. 5 lines per frame – one sample - PowerPoint PPT Presentation

Transcript of Streambank Alteration

Using Multiple Indicator Monitoring Protocols

What is MIM Streambank Alteration? The number of lines on the plot that

intercept hoof prints, hoof shears – disturbances caused by trampling.

5 lines per frame – one sample At least 80 samples per site – total of

400+ lines % Streambank Alteration = the

proportion of the 400+ lines that intercept hoof prints/shears

MIM Bank Alteration

80+ plots -400 Samples

Hoof Print & Hoof Shear Dimensions Average width = 120.8 mm Average length =171.8 mm

230mm

120 mm

Bank Shear and Tramples

Why use a simple intercept method? Simple = more efficient Simple = better agreement among

observers

Variability Among Observers – Various methods GLP: SD = 4.7, CV = 56 GL : SD = 6.3, CV = 20 BF: SD = 8.1, CV = 35

MIM (35 tests): SD = 4.3 , CV = 22.7

Heitke et.al. 2008

MIM estimates length of greenline altered: MIM: 4 “Hits” =

80%

LENGTH OF GREENLINE (within 1 hoof print ) altered = 90%

AREA OF PLOT altered = 60%

Typically the vegetated side of the greenline has fewer alterations

Simultation using actual hoof print dimensions

Results

• High Regression Coefficient• 1:1 relationship (.91 X MIM)

• Lower Regression Coefficient• 1:3 Relationship (.32 X MIM):

•MIM 20% - AREA 10%•MIM 40% - AREA 16%•MIM 60% - AREA 23%

Proper Use of Bank Alteration As a short-term indicator of disturbance

effects on bank stability and vegetation Any value assigned as a trigger to move

livestock or as a measure of grazing use is a “guideline” which must be able to change through time (See Cowley 2002)

Thus a “Term and Condition” should incorporate an adaptive process.

Bank Alteration and Bank Stability

Hartrig g er C reek

0%10%20%30%40%50%60%70%80%90%

100%

2004 2005 2006 2007 2008 2009 2010

Yea r

Per

cen

t

B ank A lteration

B ank S tability

EF Deer CreekDominant VegetationPOPR– 65%MFE – 22%JUBA – 12%SCMI – 3%% Hydric – 19%

October 2009Bank alteration:1%Bank stability: 70%

Nick Stiner, Malheur NF – Fall 2009

Christopher Christie photo 2008

June 2009

Sept. 2008Bank alteration: 24%Bank stability: 51%

June 2009Bank alteration: 4%Bank stability: 67%

Cowley 2002 – Lit Summary “Little research data is available concerning

the amount of streambank alteration that a stream can tolerate and repair each year.”

“Each of the authors mentioned above recognizes the ability of streams to repair a certain amount of bank alteration”

“The further a streambank is from the desired future condition, the less additional alteration it can tolerate and still recover to a stable level.”

Amount of Alteration that streambanks can repair annually depends upon: Stream gradient Streambed material composition, Streambank soil composition, Vegetation cover and type Channel geometry, Flow rate and timing, and “. . . concentrated impacts under rotation systems

can cause sufficient woody plant or streambank damage in a single season or year that recovery might take several years. Therefore, the best approach is to limit grazing stress to the site’s capability for annual recovery.” (Clary and Kruse 2004)

A Rational Approach to Bank Alteration Criteria and Standards Existing Condition: Compare existing

condition to a reference (best method)Bank Stability (%): Bank Cover (%): Hydric herbaceous vegetation (%)

○ (closer these are to reference the higher the allowable level of bank alteration)

Channel Type: >gradient = higher allowable level> particle sizes = higher allowable level

The Confidence Interval Any criteria requires consideration of the

precision of the measurement. CI for Streambank Alteration

32 tests○ Maximum – 11%○ Minimum - .5%○ Average – 6%

Using the CI: Set trigger at allowable level minus 6%Set standard at allowable level plus 6%e.g. If allowable level is 20%, trigger might be

set at 14%, and term and condition set at 26%.