Part 1: Mapping the Geology of the NT

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Introduction

In this tutorial your task is to create an A3 Landscape Map of the Geology of the Northern Territory using Esri’s ArcGIS for Desktop v10.2.x software. While this tutorial has a geology theme, the main objective is to employ various GIS workflows in order to create a map to meet the requirements of a particular request.

Hypothetical Request: Assume you are a GIS technician and a geoscience professional has just approached you and asked if you could make a map of the geology of the Northern Territory representing three themes: Lithology, Eon and Era. The following links will take you to Wikipedia definitions and provide some background:

This tutorial uses two data sets. Firstly, the freely available Geology of Australia data set available from Geoscience Australia, spatially documents the distribution and age of major stratigraphic, intrusive and medium to high-grade metamorphic rock units of onshore Australia.  The version of the data used in this tutorial is older than what is currently available. Note that this data undergoes continuous improvement and therefore if you need the most reliable version of the data please download and use the data via Geoscience Australia.

The second data set used is called IBRAv7. This data set is freely available from the Federal Department for the Environment and represents geographically distinct bioregions. Please visit the following link for further information and download instructions:

The data has already been downloaded & organised for you for this tutorial.

Aims and Objectives

The aim of this exercise is to competently handle geospatial data, use geoprocessing tools, creating thematic maps, applying a conic projection to geographic coordinates, and map design and production to produce an A3 landscape map of the Geology of the Northern Territory.  Through this the following educational objectives (underpinning knowledge and skills) will be met:

  • Spatial data handling including file management and data management
  • Working with Catalog to create Folder Connections and add spatial data
  • Working with multiple Data Frames and naming Data Frames
  • Applying a simple attribute query to select features
  • Use geoprocessing tools CLIP and DISSOLVE
  • Apply symbology, create Legends
  • Define spatial reference system for a shapefile
  • Using on-the-fly projection (conic projection)
  • Map design & production (multiple Data Frames on Layouts, Layout toolbar, Draw toolbar, working with legends and applying a graticule).

NOTE: This tutorial is specifically designed to cover several tools and workflows and it should be noted that outcomes of this exercise could be achieved in a more streamlined manner.

What you will need

  • File Geodatabase (fGDB) that includes two Feature Classes:
    • Australian Geology data
    • IBRA v7

DOWNLOAD THE DATA REQUIRED FOR THIS TUTORIAL HERE (~30MB)

  • Access to a computer with Esri’s ArcGIS for Desktop Basic Edition (preferably version 10.2)

Conventions:

  • If the word CLICK is used to describe an action, that mean you apply ONE LEFT CLICK.
  • IF the phrase DOUBLE-CLICK is used, that means you apply TWO LEFT CLICKS IN QUICK SUCCESSION.

Further Information:

Step 1: Setup

  • Create a folder C:\NT_Mapping – All data must go into this folder.
  • Unzip the data downloaded above into C:\NT_Mapping

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Step 2: Launch ArcMap

  • Open ArcMap (Start => All Programs => ArcGIS => ArcMap 10.2.x)
  • Remove any unnecessary toolbars. You only need the LAYOUT, TOOLS, STANDARD and DRAW toolbars. From the Customize menu, select toolbars and check/uncheck the required toolbars.

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  • Drag and dock the toolbars below your Menu bar.
  • From the FILE menu select SAVE AS… 
  • Save your ArcMap Document into C:\NT_Mapping as Mapping the Geology of the NT.mxd

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Step 3: Add Data

  • Open the Catalog window. Select the Catalog button catalog_button on the Tools toolbar.
  • Right-click on Folder Connections and Add Folder Connection.
  • Navigate to C:\NT_Mapping and with that folder selected, hit OK. This directory is now listed as a folder connection.
  • Expand the folder to show the File Geodatabase.

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  • Drag and drop both Bioregions and Geology Feature Classes either into the Table of Contents (also called the TOC) on the left or into the map window.

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Step 4: Working with Multiple Data Frames

The final outcome of this exercise is to produce a map of the Geology of the NT. For this you will need four separate Data Frames: one for the over view map, one for the Lithology Map, one for the Eons Map and a final one for the Era Map.

  1. From the Insert menu select DATA FRAME.
  2. Repeat this three times. You should now have 4 Data Frames in your Table of Contents (TOC).

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Step 4.1: Renaming and Activating Data Frames

In the above figure, the last Data Frame is BOLD. This is because this is the ACTIVE Data Frame. Data Frames can be thought of like individual maps and you can only see one map at a time. In the example above your map window should be blank. This is because there is no data yet inside that active Data Frame. Naming your Data Frames helps you keep organised.

Tip: if you can’t see your data in the map window, take a look at which Data Frame is bold. Chances are you are looking at a different Data Frame!

  • Firstly, if you right-click on the Lithology Data Frame and select ACTIVATE, you should see data in your Map View once again. Experiment with this a few times until you understand how this works.

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  • To rename a Data Frame, simply click ONCE on the Data Frame so that it is highlighted. Pause a moment and click again. You are now able to type an appropriate name for that Data Frame. Note that you can also click once on a Data Frame to highlight it, then press F2 on your keyboard. This also enables you to rename it.

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  • Rename each Data Frame as follows:

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Step 4.2: Moving Data between Data Frames

Data layers can be moved between Data Frames by dragging and dropping layers to where you need them. This creates a COPY of the data.

  • Click (once) on the Geology layer in the Overview Data Frame and drag it to the Lithology Data Frame.
  • Repeat for both Eon and Era Data Frames.
  • Right-click on the Geology Layer in the Overview Data Frame and select REMOVE.
  • Your Table of Contents should now look like this:

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This is now a good time to SAVE YOUR WORK. (File => Save or CTRL + S)

Step 5: Creating an Overview Map

For this part we are going to create a map of Australia with the NT highlighted using a different colour to the other States, just like this:

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We are using the IBRAv7 data simply because we have ready access to it but if you hunt around the internet you’ll probably discover some GIS data already prepared in this way, however you’ll learn more from doing it the way explained below.

  • Double-click on the Bioregions Layer. This will open the Layer Properties dialog box. Alternatively you can right-click on the layer and select Properties.
  • Click the Symbology tab.
  • Choose Categories => Unique Values.
  • In the Value Field select STA_CODE.
  • Select the Add All Values button.
  • Experiment with the colour ramps. Take your time to work with the colour ramps.
    • Tip: if you select the same ramp a second time it automatically randomises the colour order, so if two adjacent polygons end up with similar colours, just select the colour ramp again and hit Apply and repeat this until you like the colours.
  • Hit OK to confirm the result.

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This view has too much clutter and the tones are too strong. What we are going to do next is adjust the properties of ALL POLYGONS so that they do NOT have outlines and all polygons are the same colour – except for the Northern Territory.

  • Double-click on the Bioregions Layer.
  • If required, select the Symbology Tab again.
  • Click on Symbol and select Properties for All Symbols

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  • Apply a very pale green as the FILL and for the OUTLINE colour, select No Colour, then hit OK.

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  • All the STATE polygons should now have the same appearance.

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Now all that is required is to adjust the colour of the NT polygon.

  • Double-click on the green symbol next to the NT value.
  • The Symbol Selector will open. Choose a slightly darker green.
  • Click OK when done. Your map of Australia with NT highlighted should look something like this:

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Please SAVE YOUR WORK. (File => Save)

Step 6: Select NT and Create a New Layer

You will see below that the geology data covers the full extent of Australia. What we need to do is prepare an outline of NT and use this to clip the geology layers below.

  • From the Selection menu, select Select by Attributes…

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  • Double-click on STA_CODE
  • Double-click the equals sign (=)
  • Click Get Unique Values
  • Double-click ‘NT

Tip: Be careful of the clicks and double-clicks! Follow the instructions! If you end up with extra text, delete it and start again!

This is SQL syntax. When ready hit OK.

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All the polygons within the NT should be selected.

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This selection may now be saved as its own Feature Class within your Geodatabase.

  • In the Table of Contents, right-click on the Bioregions layer and select Data => Export Data…

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  • Navigate to your C:\NT_Mapping and Save As NT. 
  • Use the small Browse button to the right and navigate to your C:\NT_Mapping folder.
  • Double-click ON the NT_Mapping.gdb to ensure you are within the geodatabase.

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  • Hit OK when ready.
  • When completed, this will add a new layer to your Overview Data Frame called NT.
  • You can right-click on your Folder Connection in Catalog window and select Refresh. If you then expand you geodatabase you should see the new layer!

Step 6.1: Dissolve Internal Boundaries

You will now dissolve internal boundaries of this new NT layer so that we end up with a polygon outline of the whole NT.

  • From the Geoprocessing menu, select Search for Tools.

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  • This will open up a window.
  • Begin typing DISSOLVE and Dissolve (data management) should appear.

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  • Click the tool to launch it, as shown below.

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  • Select NT as the Input Features.
  • Carefully navigate to your NT_Mapping.gdb File Geodatabase at C:\NT_Mapping and name the output Feature Class NT.
  • Use STA_CODE as the dissolve field (basically all polygons with NT that are adjacent each other will be dissolved, leaving only the outer polygon).

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  • Hit OK when ready.  This will add a new layer to your Overview Data Frame called NT.
  • Click on the Clear Selected Features button on the Tools toolbar. This will clear the selected polygons from the Attribute Query above.2014-10-16_1-07-12

You now have an outline of the NT!

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Step 7: Clipping the Geology Layer

You will next use the new NT_DISSOLVE layer created above to CLIP out the Geology of the NT. This process creates a new Feature Class.

  • From the Geoprocessing menu, select CLIP.
  • For the Input Features, carefully click the browse button and navigate to the Geology layer in your geoatabase.
  • For the Clip Features, click the drop-down or carefully navigate to your geodatabase and select the NT_DISSOLVE layer.
  • For the Output Feature Class, carefully browse to your geodatabase and name the output Geology_NT.
  • When ready, click OK. Wait a moment for the process to occur.

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A new clipped geology layer should appear in your Data Frame!

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  • Drag the Geology_NT layer down to the other three Data Frames.
  • Remove all layers named Geology.
  • Remove layer NT and layer NT_DISSOLVE.
  • Remove Geology_NT from the Overview Data Frame.

SAVE YOUR WORK.

Your Table of Contents and Data Frame should look something like this:

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Step 8: Applying Symbology to the Geology

Now we are going to apply symbology to each of the three Geology layers in each of the three Data Frames.

  • Right-clik on the Lithology Data Frame and ACTIVATE.
  • Double-click on the Geology layer within the Lithology Data Frame to open the Layer Properties dialog box.
  • Click on the Symbology tab.
  • Select Categories => Unique Values.
  • For the Value Field select LITH_ASSOC.
  • Click the Symbol column header and select Properties for All Symbols…
  • Change the Outline Colour to No Colour.

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  • Click the Add All Values button.
  • Experiment with different Color Ramps until satisfied.

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  • Hit OK when done. Your data should look something like this (will look different depending on your colours):

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  • Repeat this process for the Eon Data Frame Geology_NT layer, but for the Values Field choose EON. Be sure to choose a different Colour Ramp.
  • Repeat this process for the Era Data Frame Geology_NT layer, but for the Values Field choose ERA. Be sure to choose a different Colour Ramp.

SAVE YOUR WORK!

Your ArcMap interface should now look very similar to this:

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You have now completed Part 1 of this exercise and you should proceed to Part 2.

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