Geographic Information System (GIS) software helps people visualize geospatial information. Although making maps is a big part of GIS, software such as ArcGIS and QGIS is capable of so much more. For example, users can use GIS for hydraulic modeling, perform statistical analyses, and crime analysis. In addition to the numerous applications, GIS is an important skill to learn because it makes you more marketable as a civil engineer. This is especially true if you specialize in water resources engineering or transportation engineering.
Although I am not a GIS technician, I have routinely used GIS for various aspects of my job as a consultant. In this article, I am going to share some tips and tricks I have picked up while using GIS.
Add A Map Title, Legend, Grid Or Inset Map, North Arrow, And Scale To Every Map
Maps often convey a lot of information. As a result, it is important to organize this information in a logical way. Each map should contain the following five elements:
- Map Title – A descriptive map title is an important part of any map because it describes the purpose of the map. The title should also describe the general area represented by the map. For example, “Texas River Basins” would be a more descriptive map title than “Watershed Map.”
- Legend – Another essential component of a map is the legend. This is also known as the key and describes what each symbol means.
- Grid or Inset Map – Next, your map should contain a grid or inset map. A grid contains latitude and longitude marks to which allows the reader to identify specific locations. An inset map is a smaller map that is used to convey the location of the area represented in the main map. An example of an inset map is shown below.
- North Arrow – Add a compass rose or north arrow to convey the map orientation to the reader.
- Scale – Finally, every map should contain a scale. This shows the relation between paper distance and actual distance. For example, 1 inch = 100 miles.
Keep in mind that some maps are more artistic in nature and may not need all of these elements. For example, maps that are sold as wall decor may not have everything listed above. However, if you are making a map that is technical in nature, it should have every component listed above.
How To Add A Basemap
A basemap is a collection of GIS data and imagery that forms the background of a map or map project. Some examples include Bing Maps Road, Bing Maps Aerial, Open Street Map, and World Imagery. These basemaps are available in the form of Server layers, which means you need to be connected to the internet to use them.
When I first started using GIS, I would find aerial imagery for every project. This practice took a lot of time and resulted in me using a lot of file storage space for large image files. Then I learned that there are a variety of basemaps available in ArcGIS and QGIS. Now I just add a basemap to get the general feel for an area. Sometimes I still need to download higher-quality aerial imagery, but basemap are suitable for almost all of the work I do.
How to add a basemap in ArcGIS
To add a basemap in ArcGIS, click the arrow next to the “Add Data” button as shown below.
Then can click “Add Basemap” to select the basemap that fits your needs.
How to add a basemap in QGIS
There are a couple of ways to add a basemap in QGIS. The easiest way is to use the QuickMapServices Plugin. The QuickMapServices Plugin contains a collection of basemaps for free. To add this plugin, select “Manage and Install Plugins” from the Plugins menu. Search for QuickMapServices and install the plugin. After the QuickMapServices Plugin is installed, use the QuickMapServices icon in the Web toolbar to turn your basemaps on and off.
Learn Keyboard Shortcuts
GIS work often requires a significant amount of clicking. After a while, this repetitive motion can get tiring. Using keyboard shortcuts not only makes you more efficient but gives you a little break from the mouse. The table below lists the keyboard shortcuts available in ArcGIS. There are probably many other shortcuts available in ArcGIS, but this list consists of the ones I find most useful.
| Shortcut | Description |
| CTRL+N | Opens a new .mxd file |
| CTRL+O | The “open” dialog box appears |
| CTRL+S | Save |
| ALT+F4 | Exit the project |
| CTRL+Z | Undo |
| CTRL+Y | Redo |
| CTRL+X | Cut |
| CTRL+C | Copy |
| CTRL+V | Paste |
| F1 | ArcGIS for Desktop Help |
| CTRL+F | Opens the search window |
| F3 | Moves the focus from the Catalog window or the Table Of Contents window to the map display. |
| CTRL | Hold down CTRL while dragging a toolbar or dockable window to prevent it from docking. |
| F5 | Refresh and redraw the display |
| F9 | Suspend or pause drawing so you can make changes to your map without having the map redraw after each change. Press F9 again to continue drawing the map. |
| Space Bar | Turns drawing of the selected layers on or off |
| F2 | Renames the selected item |
| F11 | Activates a selected data frame |
There are also several keyboard shortcuts available in QGIS. To view the keyboard short cuts available, select “Keyboard Shortcuts” from the Settings menu. QGIS also allows users to change or set their own keyboard shortcuts.
Stay Organized
When I first started using GIS, I put all of my data into one working folder. While that was okay for simple tasks, this system would often result in a cluttered and confusing working folder. When you are performing several operations or working on complex analyses, it is extremely important to organize your data. Typically, I will set up a geodatabase that contains at least three feature datasets: raw datasets, intermediate datasets, and final datasets. Each of these feature datasets may contain more sub-categories. A raw dataset is the shapefile or raster you download directly from the internet or get from a client. Intermediate datasets consist of re-projected data, clipped data, dissolved data, etc. Final datasets are comprised of the processed dataset that is used in a map.
If you do not want to use a geodatabase, you could also set up a “raw datasets” folder, an “intermediate datasets” folder, and a “final datasets” folder.
Use A File Geodatabase Instead Of A Personal Geodatabase
A file geodatabase (.gdb) is a collection of files that can store, query, and manage spatial as well as nonspatial data (e.g., tables). A personal geodatabase (.mdb) is a Microsoft Access Database that can also store, query, and manage both spatial and nonspatial data. The most significant downside of a personal geodatabase is that it has a size limit of 2 GB. In addition, only one person can edit a personal geodatabase at a time. For these reasons, it is better to use a file geodatabase, especially for larger datasets.
Learn ArcPy
ArcPy is the Python package used to code custom functions in ArcGIS. Understanding how to code your own scripts to perform custom functions will make ArcGIS an even more powerful tool. To use ArcPy, click on the Analysis tab. Then click the Python button. The Python window will appear.
If you have any programming experience, you will pick up ArcPy rather quickly. If you are interested in learning ArcPy, check out Tim Buchalka’s ArcPy for Python Developers Using ArcGIS Pro course on Udemy. Click here to view the course.
Share Your Work Using Map Packages
When I first started working with GIS, I would give my coworkers the .mxd and all associated data. This would result in very large file sizes, broken links, or both. This all changed when I started using Map Packages to share my work. Map Packages (.mpk) contains the map document (.mxd) and all referenced layers in one file.
To prepare a map package, start by entering all of the information required by ArcGIS in the Document Map Properties dialog box (File > Map Document Properties). This includes the map title, description, author, credits, and tags. Make sure the checkbox for “Store relative pathnames to data sources” is checked. Then click File > Create Map Package and follow the prompts to start packaging your map. It may take a few minutes for ArcGIS to complete the process.
Export High-Quality Maps
The default resolution in ArcGIS is 300 dots per inch (dpi). This resolution works well for drafts or maps created for internal use. However, you want to export maps with a higher resolution when you deliver a final product. I recommend exporting maps at a resolution of 600 dpi when you are in the final production stage. This will result in maps that have a crisp and professional appearance. Keep in mind that it will take ArcGIS longer to export/print when you specify a higher resolution.
Where To Find Free Geospatial Data
You may find yourself spending a lot of time hunting down data. This is typical. If you have no idea where to start, check out these tips for finding free GIS data online. Keep in mind that this list is applicable to projects in the United States. Unfortunately, I am not very familiar with international GIS resources.
- The National Map (TMN) has many free datasets available for download.
- The Natural Resources Conservation Service’s (NRCS’s) Web Soil Survey contains free soil data.
- The United States Census Bureau has TIGER data available for download here. This dataset consists of jurisdictional boundary datasets as well as some road data.
- The National Land Cover Database contains land use and impervious area data for the United States. This data is fairly course, and therefore, is only useful for watershed-scale exercises.
- Check city or county websites for GIS data. Some cities or counties require payment for GIS data.
- Many states have a GIS Data Portal or GIS Data Clearinghouse that contains many datasets organized by county or city.
- State Transportation agencies often have railroad, roadway, and airport data available on their websites.
Read The Metadata
Metadata contains information about the GIS dataset. This information includes the source of the data, the projection, the data modified, and the purpose of the dataset. Because data is the foundation of every GIS exercise, it is important to understand the limitations of the data you are using.
Write Down Workflows
A workflow describes the sequence of events required to complete a complex project or task. It is important to keep track of the steps you took to perform an analysis. This does not have to involve creating fancy flow charts or anything like that. You can simply record your workflows in a notebook or in a Word document. Whatever format you choose, writing down your workflow will help you (or others) repeat the analysis in the future. Recording every step in your workflow will also help you explain your process more exactly to a client or in a report.
Data Driven Pages
Data Driven Pages is a tool in ArcGIS that allows you to create map books quickly. Rather than setting up several maps, the Data Driven Pages tool will export a series of maps based on an index. The index is a grid of polygons that represents the extent of each map. An example of an index is shown below. ArcGIS would create a map for each polygon shown.
In addition, you can specify various aspects of each map (e.g., scale, map title) by creating and populating columns in the index layer.
Use ArcCatalog
ArcCatalog is a part of the ArcGIS suite and allows you to manage and organize your geospatial datasets. When I first started using ArcGIS, I would organize my data in ArcMap. However, it is much easier to do this work in ArcCatalog. ArcGIS allows you to select a specific dataset, view its properties, and write metadata. The video below will help you get started using ArcCatalog.
Know The Difference Between Raster and Vector Data
Geospatial data can be categorized as either raster or vector data. Raster data is comprised of a grid of pixels. Each pixel represents a single value or class. For example, each pixel represents a specific height in an elevation dataset, and each pixel represents a specific land cover type in a land use dataset. Rasters can represent continuous data (e.g., elevation) or discrete data (e.g., land use). Discrete data usually consists of integers that represent classes. For example, a value of 1 might represent urban areas, and a value of 2 might represent a forest. Satellite data and remote sensing data are typically stored as a raster. Although raster data has a more pixelated look to it, this format is useful when you want to perform map algebra functions. Raster data is often presented as a georeferenced jpeg, tiff, png, or pdf.
In contrast, vector data is not made up of a grid of pixels. Rather, vector data is comprised of vertices and paths. The three types of vector data are points, lines, and polygons. Point data may represent address points or water quality monitoring locations.
Line data may represent roads, channels, streams, or any other linear feature.
Polygons may represent building footprints, parcel data, or agricultural fields.
Vector data is typically stored as a shapefile or in a geodatabase. Because vector data is not comprised of a grid of pixels, it tends to have a smoother aesthetic. Unlike raster data, you can also associate several attributes with each feature of a vector dataset. For example, you could specify the soil type, hydrologic soil group, and permeability of each feature in a soil dataset. Vector data is not good for storing continuous data (e.g., elevation).
Keep in mind that there are tools available in ArcGIS and QGIS that convert raster datasets to vector datasets and vice versa.
How to Learn GIS Affordably
An ArcGIS license is very expensive. Even a basic ArcGIS license costs more than what most people are willing to spend to learn GIS. Fortunately, there are a few ways to learn GIS without breaking the bank.
ArcGIS Personal Use
If you want to learn ArcGIS on your own, ESRI offers a license for people who want to learn the program at home. It costs $100/year and provides you access to the whole range of ArcGIS capabilities. This license also comes with access to ESRI’s self-paced e-learning courses. Keep in mind that this is a non-commercial license. Click here to learn more about this product.
QGIS
QGIS is an open-source GIS application and is available for free. Although ArcGIS is the standard software used in the vast majority of civil engineering firms, QGIS is similar to ArcGIS in many ways. The knowledge you gain from practicing your GIS skills in QGIS will transfer over nicely to ArcGIS. Click here to learn more about QGIS.