Monthly Archives: December 2014

Teaching about Watersheds and River Systems with ArcGIS Online

Teaching about watersheds and river systems has long been a major theme of physical geography, earth science, and environmental science instruction.  ArcGIS Online now provides capabilities for educators and students to create watersheds, trace downstream, and create viewsheds, all of which can serve as an effective means to foster understanding of watersheds and river systems, how they are connected geographically and temporally, and why they are important.

Boulder, Colorado, like many mountain-front communities, is prone to periodic devastating floods.  To supplement a lesson that I wrote about floods in Boulder, I used the watershed tool in ArcGIS Online to create the watershed that is drained in Boulder Creek through the mouth of Boulder Canyon.  The area is 130.12 square miles, giving a clear reason why any major rapid snowmelt or any major rain event anywhere in that large area creates flood hazards for the city of Boulder.

Watershed upstream from Boulder Colorado

Watershed upstream from Boulder Colorado.

Where does that water flow once it reaches Boulder?  To find out, I used the new Trace Downstream tool with a 15 mile limit.  The result makes it clear that the areas east and northeast of the city also bear the effects of potential floodwaters.

Trace 15 miles downstream from the mouth of Boulder Canyon, Colorado

Trace 15 miles downstream from the mouth of Boulder Canyon, Colorado.

Using the same tool, I ran another Trace Downstream analysis and extended the distance to 3,000 miles.  The result, shown below, fits in well with the lesson but also in any lesson that asks students, “where does a cup of water flowing from my location flow through before it reaches the ocean?”

Trace from Boulder Colorado to the Gulf of Mexico

Trace from Boulder Colorado to the Gulf of Mexico.

Finally, to get a sense for how the terrain in Boulder is mountainous to the west of the mouth of the canyon but flattens to the Great Plains to the east, I used the new Create Viewsheds tool from a point on top of Green Mountain, above the famous Boulder Flatiron rock formations.  The viewshed, as the name implies, indicates the land viewable from a specific point, and in my case, I specified nine miles for the extent. The result of viewshed analysis can foster understanding of the terrain and how the terrain impacts streamflow and flooding.

9 mile Viewshed from Green Mountain

Nine-mile Viewshed from Green Mountain.

These activities require an ArcGIS Online organizational subscription and to generate the analysis layers such as the ones I did above, you need to have publishing rights in that organization.  With your organizational subscription, examine the map I created above, and try these tools yourself for your own area!

You’ll be amazed at how easy it is, and yet how powerful, because these tools can foster understanding of how streams, watersheds, and terrain are connected spatially and temporally.

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Fun with GIS 169: A New Dimension

Maps in ArcGIS Online just took on a whole new dimension. “Web scenes” can display in 3D in certain desktop browsers. This bit of map magic relies on WebGL, so users of recent versions of Firefox, Chrome, and Safari will be happy; see ArcGIS Online Help for more info, as even recent browsers may need a configuration tweak.

World population atop the oceans basemap, in an ArcGIS Online web scene.

Building, saving, and sharing maps in a web browser has been a tremendous boon for education, but reactions when I showed an equal area world map told how dramatic the distortion is in Web Mercator displays to which we have grown somewhat accustomed. The arrival of good global displays and high speed navigation is breathtaking. The ability to add in many of the same layers we had used in 2D means a much more realistic vision of small-scale (large area) content.

Oblique view of the Grand Canyon, looking WNW. Note compass in lower left, horizon in back.

There is a tremendous amount of new capacity in the December 2014 ArcGIS Online release. But, for me, nothing will match the educational impact of being able to view the globe in a browser, and create/ save/ share presentations as easily as in 2D. Many of us will be madly revising lessons for months to take advantage of this new capacity. It’s a whole new world!

Charlie Fitzpatrick, Esri Education Manager

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Teaching GIS in a Computer Science Course, Part 2

In a recent post, I introduced how GIS can be successfully integrated into a computer science course.  While my syllabus was only for an extended single class period, these ideas can be expanded into several weeks of content and can also be used to build a GIS-focused computer science course.  After I used the ArcGIS presentation capabilities to introduce GIS, spatial analysis, and discussed programming languages and workforce skills with the students, we began exploring the main Esri ArcGIS for Developers site.  We then investigated the developers’ site ArcGIS API for JavaScript.  This is a wonderful site for instructional use–as a source of specific tasks to be assigned, for whole-class work and instruction, and for small groups to work on.  One of my favorite things about the site is the “explore in the sandbox” capability.  As the name implies, this allows for students (or anyone) to adjust the code and see how that code affects the map.  Not only does this mean instant gratification for the students coding in class, but because the code is displayed side-by-side with the map, they can quickly see how the code works and how web mapping is driven by code.  The image below, for example, shows the map after the basemap was changed to “OSM” (OpenStreetMap) and the zoom level was changed to 14.  While we investigated the Python for ArcGIS Community resources, we discussed recent GIS Python books here and here as well, and talked about the importance of connecting with the coding community, locally and globally. I encouraged them to attend one of the local Developers’ MeetUps hosted by Esri.

We also explored the the ArcGIS API for JavaScript samples page and the JavaScript Quickstart on GitHub.  Again, we adjusted code to accomplish things such as adding graphics to maps, shown here.  We then explored the ArcGIS Runtime SDK (Software Development Kit) for Java.  A logical next step would be to lead students into the Web AppBuilder for ArcGIS.   This new resource provides a foundation for building intuitive, focused web applications in ArcGIS that run anywhere, on any device, without writing a single line of code.   However, by using the site and the sample code resources above, students learn about coding and are on their way of writing their own.  And since so many of these apps are meant to be run on mobile devices, students are drawn to it in part because they are required to make heavy use of their smartphones in class!

I finished by having a discussion with the students on my colleague Andy Gup’s relevant and timely 10 tips for new web developers, and my GIS reflections on the 10 skills the future workforce will need.

I challenge all of you in the GIS community to look for opportunities to build bridges with the computer science community.  The opportunities for programming within the field of GIS are rapidly expanding and through them, students could make a far-reaching contribution not just to the field of GIS, but to society as a whole.

ArcGIS API for JavaScript Sandbox

ArcGIS API for JavaScript Sandbox.

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Teaching GIS in a Computer Science Course, Part 1

I was recently asked to teach a class about GIS as part of a computer science course.   I would like to share this with the community, and open up the discussion to the broader issue of the linkages between GIS and computer science.

I challenge all of you in the GIS community to look for opportunities to build bridges with the computer science community.  As part of your outreach, you could demonstrate that all GIS software has been developed through coding and testing, show through the Esri developer sites how code makes web GIS work, show real job ads indicating specific programming skills required, and offer resources for further exploration.

I began the class by stating that the opportunities for programming within the field of GIS have never been greater than today, because the need has never been more acute.  I followed this by mentioning everyday problems that are solved because someone in GIS has learned to effectively code to solve that problem.   Next, I addressed the following elements:

  • What are geotechnologies?  GIS, web mapping, GPS, and remote sensing.
  • Why are geotechnologies important to society?
  • Mapping and spatial analysis in GIS.
  • Programming languages important in GIS.
  • Workforce skills you should consider developing to be successful in GIS and computer science.

To address these elements, I used several ArcGIS Online presentations that I have shared in this gallery as an introduction for what GIS  is, why it matters, and its connections to computer science.  I love using the presentation mode in ArcGIS Online because I am using GIS to teach about GIS. Furthermore, I requested to be in a computer lab so we could do hands-on work mapping some data because I feel it is critical to be active learners in GIS.  The mapping included activities such as bail bonds and car washes in Oklahoma City, to foster discussion about spatial patterns, but also on databases and geocoding.  I believe that the ability to construct and use a simple database is essential.  We then used proximity and hotspot and other analysis tools on these geocoded businesses.  Along the way, we discussed such themes as being critical of data, including mapped data, managing error and uncertainty, being careful about where files are stored, what is online versus on the local computer, being careful about how you construct your database.

We then discussed the languages and platforms most often used in Esri mapping technology.   When it comes to anyone learning programming, especially for the web and GIS, HTML, CSS, and JavaScript are the three essentials.  I showed the most common developer APIs (Application Programming Interface) and SDKs (Software Development Kit), such as JavaScript, and for both Android and iOS.  We discussed what GitHub is and why we use it in GIS, the Git repository web-based hosting service that offers distributed version control and source code management functionality for software development, particularly useful for a rapidly-evolving technology such as GIS.  We discussed our most common JavaScript Github repositories, such as Esri Leaflet, used to build web mapping applications, supporting HTML5 and CSS3, and Bootstrap-map-js, a lightweight JS/CSS extension for building responsive mapping apps with ArcGIS and Bootstrap 3, and the Terraformer conversion library, a geometric toolkit for dealing with geometry, geography, formats, and building geodatabases.

In my next essay in this blog, I will discuss the activities I created, with the advice of our Esri development team, for the second part of this class.

ArcGIS for Developers site

ArcGIS for Developers site.

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