9560

• UCREFRP Catalog Number: 9560
• Author: Valdez, R. A.
• Title: A Generalized Interactive Model to Predict Floodplain Habitat Area Needed to Recover the Endangered Razorback Sucker in the Upper Colorado River Basin - Floodplain Model Version 5.1.
• USFW Year: 2004.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

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depressions, terraces, or backwaters by specifying location of entrainment and working through
the model with survival, growth, etc. for a particular site. Once the drift sub-model is
implemented, the floodplain model treats all floodplains as one large area with user-specified
input variables. Output from this sub-model helps the user determine the input for percentage of
drifting larvae entrained in floodplains for the floodplain model.
Worksheet 3: "SiteSurv".- This worksheet provides site-specific entrainment and
survival input for 14 floodplain sites on the Green River between Split Mountain and Ouray.
Worksheet 4: "Sensitivity".- This worksheet contains four scenarios and 17 tests of the
input variables in the model that provide insight into the most sensitive variables (i.e., those that
have the greatest effect on output with the smallest change), as well as the inter-relationships of
the variables. This worksheet is not part of the working model, but is presented for user
information to assess sensitivity of certain variables.
Worksheet 5: "Data Sources".- This worksheet identifies sources of data used in the
model.
The seven charts contained in FLOODPLAIN are:
Chart 1: "Length-Wt".-This chart illustrates the length-weight relationship for female
razorback sucker from fish captured in the Upper Colorado River near Grand Junction, Colorado
rv aldez et al. 1982). The exponential relationship provided in this chart is used to compute fish
weight for specified length:

y = 0.0006X2.3598 , R2 = 0.576
Chart 2: "Fecundity" . -This chart provides the relationship of fish weight to total ova
for fish of a given weight, and for ova per kilogram of fish weight. These relationships are based
on data from McAda and Wydoski (1983), Minckley (1983), Marsh [unpublished], Minckley et
aI. (1991), and Hamman (1985). The former relationship is used in the model:
y = 0.1584X2 - 213.19X + 74084, R2 = 0.993
Chart 3: "Larval Entrain".-This chart illustrates the number oflarvae entrained at
each river mile according to the percentages specified by the user in sub-model A in the "Drift"
worksheet.
Chart 4: "Drift Survive".- This chart illustrates the number of larvae surviving and

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