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Design and Analysis Example for Indiana Wabash Basin Streams

Illustrative Example: The following example is based on the Upper Wabash Basin. The Design was completed in 1998, field sampling conducted in 1998, and results reported in 2000. All files needed to reproduce the analysis can be downloaded, including the statistical software R and code. Results are included for comparison and cross-checking. However, some project specific details have been simplified for this example. The Indiana 2000 Report combined the results from the original analysis with other data and the results presented on this web site are not intended to reproduce those in the Report.

A second example for a continuous population is presented based on Coastal Estuaries, including target population with two sub-populations (Tidal Creeks, Open Water) and two years of data. Hopefully, these examples and guides will facilitate the analysis of additional probability monitoring datasets.

Operational Guidance, Supporting Files, Objectives, Institutional Constraints, Target Population, Resource Characteristics, Design Requirements, Frame Materials, Sample Frame, Survey Design, Design File Selected Sites, Site Status File, Design Status File, Results.

Operational Guidance: To reproduce the analysis results from the data files, it is recommended that you follow these steps:

Supporting Files:

Monitoring Objectives  
  • Assess and predict with reasonable certainty the percentage of unimpaired and impaired stream miles within the Upper Wabash River Basin
  • Assessment of both Biological Status and Water Chemical Status
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Institutional Constraints

  • Information needed on water chemistry, fish tissue and fish community, macroinvertebrate community, and habitat assessments
  • Flexibility to sample more Chemical than Biological Sites

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Target Population

  • All perennial streams contained in Wabash basin within the geographic boundaries of Indiana
  • Strahler order 1 - 4 streams within HUC units: 05120101, 05120102, 05120103, 05120104, 05120105, 05120106,05120107. Restricted HUC areas to be within Indiana.

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Resource Characteristics

  • Stream reaches coded "R" (regular reach), "S" (start/headwater reach), "T" (terminal reach), "N" (non-networked reach), and "W" (wide river - one bank only).
  • Strahler orders 1st, 2nd, 3rd, and 4th (Strahler, 1957)

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Design Requirements

  • Target sample size of 50 (or more) sites for chemical data collection per basin
  • Target sample size of 50 (or more) sites for biological data collection per basin
  • Overdraw 50 sites per basin to accomodate denied access, non-target, etc.
  • Approximately equal number of samples in each Strahler order category

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Frame Materials

  • 1:100,000 scale of U.S EPA's RF3-Alpha data set
  • Strahler order 1 through 7
  • Basin Boundaries based on Hydrological Unit Catalog (USGS)
  • Indiana State Boundaries

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Sample Frame

  • US EPA's Reach File Version 3 - Alpha (RF3- Alpha)
  • Strahler order 1st, 2nd, 3rd, and 4th streams
  • Basin Boundaries based on Hydrological Unit Catalog (USGS) units: 05120101, 05120102, 05120103, 05120104, 05120105, 05120106,05120107.
  • Indiana - Ohio State Boundary

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Survey Design

  • GRTS for linear continuous network
  • Multi-density categories by Strahler Order with approximately equal number of samples
  • Expected sample size 50 (or more) sites per basin
  • Oversample of 50 sites per basin

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Design Documentation and Summary: Design Request and Frame Statistics for Upper Wabash River Basin, 1998.(pdf 278 KB)

Weighting Factors for selection of probability sites


Design File Selected Sites


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Site Status

  • Results Database - Site sampling forms, laboratory analyses, etc. Not included in this example.
  • Site Status File (Format & site example)
  • Site Status File 1998 Upper Wabash River Basin (txt 10 KB)
  • File includes calculated indices and impairment status

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Design Status File

  • Combines Design File and Site Evaluation Information
  • R code procedures to combine and adjust weights (txt 3 KB)
  • Design Status File 1998 Upper Wabash River Basin Example (txt 25 KB)
  • Note: The initial design was based on a sample size of 50. Site sampling included all 100 sites. Final weights approximately 1/2 initial weights.

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An Overview of how it all fits together


Analysis Approach

  • Estimates Target Population Statistics (requires psurvey.analysis procedures)
  • R code procedures for estimation and CDF-plots (txt 6 KB)
  • Stratum, Site Evaluation Catagories, IBI and QHEI Estimates
  • Estimates CDFs for IBI and QHEI indices for percent stream length and stream length (km)

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