Preparing for Analysis

Figure 1. Analysis and reporting workflow: Steps for preparing for analysis

Your management goal or question(s) will guide your analysis. Refer back to your completed Monitoring Design Worksheet and related GIS files to provide important context as you embark on your data analysis efforts. The following steps are a guide to preparing for both aquatic and terrestrial data analysis (Figure 1). For assistance with any of these steps, please contact the AIM Aquatic Analyst, Nicole Cappuccio (ncappuccio@blm.gov) or the Terrestrial AIM Lead, Emily Kachergis (ekachergis@blm.gov).

In order to analyze your data correctly and with as little error as possible, you will first need to gather data and complete the documents below. If you have an active project, please start at step 1; however, if you are simply using already existing data, skip steps 1-2.

Step 1: Ensure field data and design tracking file submitted to NOC

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One month after field data collection is completed:

QC your field data and submit all final field data to NOC/NAMC

  • QC and send final DIMA for terrestrial projects.
  • For aquatic projects, final data should be QCed and submitted after each trip but make sure the last trip’s worth of data has been submitted. Additionally verify that NAMC has received all field data by consulting the appropriate columns the design tracking file.

Review your Plot/Design Tracking files for completeness and submit to NOC

Your Plot/Design Tracking file (Aquatic Design Tracking Example & Terrestrial Plot Tracking Excel Template) should contain all points in your design for a given year and track all points that were evaluated. If you are a project lead, your Plot/Design Tracking file should have been filled out iteratively throughout the field season. One month after each field season, you should submit this to the NOC so that design databases can be populated with this information. This information is then used in weighted analyses. However, even if you are not doing weighted analyses, design tracking files are still important because they are also used in the data QC process in tracking what plots/reaches were sampled. To complete your file, do the following:

  1. Fill out “Final Designation/Status” for every site that was evaluated. This includes not only points that were field visited but also points that were evaluated using GIS or other methods.
  2. Possible final designation options are listed below:
    1. Sampled
    2. Non-Target
    3. Inaccessible
    4. Unknown
    5. Not needed
  3. When deciding the status of each point, make sure to critically review statuses assigned by field crews. Refer to terrestrial and aquatic rejection criteria on the Point Evaluation & Rejection page for further guidance on assigning final designations.
  4. For further guidance for filling out the Terrestrial Plot Tracking file see the this documentation.

If you do not have an active project, you can skip this step.

Step 2. QC & Store data and compute indicators

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After receiving final data, the NOC/NAMC does additional QC and computes indicators using R scripts. Design tracking files are ingested into design databases and used in the data QC process to determine which sites were sampled. Computed indicators are then ingested into TerrADat and AquADat. Additional custom indicators may be computed using DIMA and/or R. See the Data Storage page for more information.

Step 3. Identify management goals & develop quantitative monitoring objectives including benchmarks

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If you are a project lead, the monitoring design worksheet should contain the information needed for this step and should have been completed during the design phase of the project. Specifically, Steps 1-3 of the Monitoring Design Worksheet are needed for this portion of analysis. Additional resources for selecting benchmarks can be found here and additional resources specific for Aquatic AIM data can be found within the Aquatic Benchmark Tool and detailed metadata for aquatic indicatorsIf you do not have an active project but want to conduct an analysis on data that is already available, you may skip the step of filling out this worksheet, but you will need all the information below to fill out your Benchmark Tool. 

  1. Management Goals
  2. Monitoring Objectives
    1. Reporting Units
    2. Description of Target Population
    3. Indicators of Interest
    4. Benchmarks
    5. Proportion achieving desired conditions (if doing weighted analysis)
  3. Original Strata used in the Design

Step 4: Gather and understand your field data

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  1. DIMA/TerrADat
    1. Getting data from TerrADat
      1. The public can access TerrADat via the BLM’s Landscape Approach Geoportal.  If you are a DOI employee, please consult the Accessing Terrestrial AIM Data_V1.3  to learn how to view terrestrial monitoring information using the feature services.
      2. TerrADat will be updated each year around the new year with the new data from the previous field season. If you need computed indicators prior to this, you can use the indicator reports within your DIMA.
    2. For help interpreting terrestrial indicators and indicator metadata, go to (TBD link, contact Emily Kachergis (ekachergis@blm.gov) for immediate questions).
  2. SARAH/AquADat for aquatics projects
    1. Getting data from AquADat
      1. If you are a BLM employee, follow the AquADat instructions to access Aquatic AIM data. AquADat provides web-based access to all calculated Aquatic AIM indicators collected from 2013 to 2016. If you are not a BLM employee data requests can be made by contacting Scott Miller (swmiller@blm.gov).
      2. AquADat will be updated with Aquatic AIM data from 2017 in February of 2018. If you have immediate 2017 data needs prior to February, please contact Jennifer Courtwright (jennifer.courtwright@usu.edu). For future field seasons, we hope to have preliminary computed aquatic indicators available using an online interface immediately after data collection.
    2. For help interpreting aquatic indicators and indicator metadata, use the detailed metadata for aquatic indicators document.

Step 5: Gather GIS information related to your design (Terrestrial Only)

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  1. Reporting Units (ideally GIS files).  These are specific areas where you need information such as indicator values.
  2. Benchmark Groups (ideally GIS files, if applicable). These are groups of monitoring points that have the same benchmark for evaluating the success of a particular monitoring objective.  For example, if you have points across your entire field office but want to  evaluate a sage grouse habitat objective, only the points that are within sage grouse habitat should be considered for that particular objective.

Step 6: Determine appropriate analysis

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There are many ways to use AIM data. You can look at individual AIM plots or a group of plots, and you can combine AIM with other types of information. There are many different analysis approaches that you are likely already familiar with. Because AIM data are often collected using a spatial random sample, one specific analysis option to consider is a weighted analysis.  A weighted analysis produces the percentage of the resource in a given condition on the landscape, with known level of confidence.  An example result of a weighted analysis is: “75% (+/- 8%) of brood-rearing sage grouse habitat is in suitable condition.”  See the Terms and Concepts page for more information about weighted analyses.

Consider the following criteria suggesting that a weighted analysis may be appropriate for using AIM data to answer your management questions.  

Criteria suggesting use of weighted analysis

  • Policy requires weighted analysis (e.g., X% of resources are in a certain condition)
  • Large area/stream extent
  • More than 10 monitoring points are available from a probabilistic sample design, or capacity to collect this number is present
  • Known level of confidence is desired
  • More complex resource decisions

Many common land management decisions will not require a weighted analysis.  For example, many grazing authorization renewals are for relatively small areas with insufficient capacity for collecting more than 10 monitoring plots/reaches.  However, if your situation matches most of the criteria for weighted analysis and you are interested in this analysis, then you should consider a weighted approach. If you are unsure, but want to consider a weighted approach, please contact the National AIM team to discuss. Sage grouse habitat assessments and Land Use Plan effectiveness are common applications of weighted analyses.

See the examples of AIM data in use for options of how you can use AIM data.

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