Tag Archives: ArcView
Because ArcGIS Online includes imagery from several different sources collected at different times, ArcGIS Online can be effectively used to study landscape change. Recently I was teaching at the Esri East Africa office in Nairobi, Kenya, in a neighborhood experiencing rapid transformation from residential to large office blocks. After my class gathered data about street lights and streets using ArcPad running on a Trimble Juno device, we transferred that geodatabase to my computer and started ArcGIS 10. Next, I needed a base map to display behind my field-collected data. In the case of Nairobi, the best street data was from OpenStreetMap, a layer easily obtained from ArcGIS Online. Then I easily added two images from ArcGIS Online—the Esri world imagery layer, and the Bing imagery layer. The imagery layers were both useful because they allowed us to examine two different years, the Esri imagery layer (2004) and the Bing imagery layer (2010).
Now I could assess the amount of change in the neighborhood. Using the swipe tool on the Effects toolbar allowed me to easily and dynamically compare the two images. The building housing the Esri East Africa office (just north of the soccer field in middle right) did not exist in the older image, yet the boarding school across the soccer field was visible on both images.
This same technique could be used to examine your own neighborhood or any area on the planet that you are interested in studying that may have experienced human or environmental change—an area recently scorched by wildfire, converted from rangeland to farmland, covered with roads or houses, scarred by a landslide, or impacted in other ways.
Another point worth noting is that since ArcGIS Online imagery covers the world, no matter where your study is located, you will be able to obtain a base map. And, what’s more, the base maps overlay perfectly with your other data. How things have changed from a few years ago when it was difficult to obtain a base image for many areas of the planet—much less, one that overlaid your field-collected data!
What changes can you detect using imagery from ArcGIS Online?
-Joseph Kerski, Esri Education Manager
Most of us, whether at the beach, in the garden, or in a sandbox, have drawn words on the ground. Have you ever drawn something with your GPS receiver? As you probably are aware, all GPS receivers automatically record a track of your position. A track is analogous to you dropping bread crumbs every so often to mark where you have been. You can walk in such a way as to trace shapes of various kinds that are recorded on your track. These shapes can be letters, circles, squares, or others. Begin by examining websites showing track results, from http://www.gpsdrawing.com/gallery.html to contributions to OpenStreetMap, and others. One of the earliest GPS drawings I ever saw was a decade ago where someone drew the word “IF” in England using a car. Each letter stretched from far north of London all the way down to the English Channel!
When you return from the field, you can upload these shapes into your GIS. Use an image or map from ArcGIS Online as a backdrop for your track.
As you can see in the ArcMap session above, I drew the words “GIS” with my receiver. I often include GPS drawing while working with teachers and students and I encourage you to do the same. Why? Drawing with GPS forces us to think about spatial relationships. We must be aware of where we have walked, noting local landmarks, so that we do not cut across letters that we have already drawn. How can I walk so that each letter is shaped correctly, is distinct from other letters, and is aligned so that the word lies on an east-west axis? In the example above, because the streets on the Colorado Community College System were aligned northwest to southeast, I had to be careful not to follow the street grid, but cut diagonally across lawns for optimal results. How could I have done better? How does changing the track setting from distance to time, or changing the distance or time interval between recorded track points, alter the appearance of the letters? For added interest, have students draw their first or last name.
What shapes would you like to draw with your GPS?
- Joseph Kerski, Esri Education Manager
Last week, I attended the ESRI Developer Summit. (No, I’m not a “developer,” but I work with some.) This is a gathering of people who work with ESRI’s GIS technology (for desktop, server, or mobile platforms), creating new products or custom solutions in response to challenges faced by people and organizations in all walks of life. Here is a lesson for education to consider.
Developers must construct solutions to problems that evolve constantly. Software changes, operating systems change, hardware changes, the world changes. Solutions that worked yesterday do not adequately meet the needs of today. The developers need to keep learning and creating … or they simply become obsolete.
The world is fundamentally different from that of 50, 25, or even 10 years ago. Are the activities in today’s classrooms effective responses to these shifts? (Some classrooms clearly are different; see my blogs from March 15 and March 8, and look here again in coming weeks, as I check out more school stories.) Education today needs to prepare student for increasingly rapid change. Many jobs that will exist in 10 or even 5 years have not been invented yet. Lectures, worksheets, and activities of yesteryear have little appeal for today’s digital natives — tomorrow’s workforce. Preparing for days gone by does not help a planet at once more interconnected and strained.
More and more educators are realizing that GIS offers an opportunity to redesign instruction. As we noted in a 1995 document called “Exploring Common Ground“, GIS is a technology that can help change how we do school. Merging diverse data to engineer different views of conditions and challenges is exquisite practice for today as well as tomorrow. Integrating systems, understanding context, rejecting simplistic thinking for holistic design, coping with diversity, planning for evolution, working toward informed decisions about scarce resources … these are hallmarks of life with GIS, and critical tasks for education in the 21st century.
- Charlie Fitzpatrick, Co-Manager, ESRI Schools Program
Classroom science teachers – be sure to catch “The Urban Tree Project” in the February issue of The Science Teacher by Michael Barnett, Meredith Houle, Elizabeth Hufnagel, Alexander Pancic, Mike Lehman, and Emily Hoffman.
“Geospatial technologies have emerged over the last 15 years as one of
the key tools used by environmental scientists (NRC 2006). In fact,
educators have recognized that coupling geospatial technologies with
environmental science topics and scientific data sets opens the door to
local and regional scientific investigations (McInerney 2006). In this
article, the authors describe the use of geographic information system
(GIS) technologies and computer modeling to engage students in
determining the economic and ecological value of trees in their
neighborhoods while participating in the Urban Tree Project.”
Details available from the National Science Teachers’ Association
Once again, we have been delivered a stunning lesson in earth science. A tremendous earthquake (magnitude 8.5 or so) rocked Chile this weekend, spawning tsunami warnings across the Pacific. The questions I, as a geography teacher, would have asked my students are my standard three: “What’s where? Why is it there? So what?” I wondered especially about this quake versus the one which caused such suffering in Haiti a month ago. To look at these, I decided to make some simple but powerful maps in ArcView. It turned into a nice example of how “GIS is a power tool for STEM” (Science, Technology, Engineering, Mathematics).
From the USGS Global Earthquake Search website I downloaded the earthquakes of January and February, 2010, with magnitude greater than 2.0, and saved it as a text file. (This took one minute.) In Notepad, I cleaned up the header and footer, visually scanned the data and fixed two bad records, then used “global replace” three times to convert the data into my preferred format for GIS display [download file]. (Two more minutes.) In ArcView, I added just the quakes, then copied and pasted the layer to generate two versions. I set the lower layer as graduated circles based on magnitude and coded the upper layer by color based on depth. (Three more minutes.) Right away, interesting patterns showed up.
Wow, look at the subduction zones! Next, I added some background from ArcGIS Online and zoomed in to the relevant area of South America and the Caribbean. (One minute.)
The subduction zone of western South America popped out like a sore thumb, so I decided to see it in 3D. I exported the data to a shapefile, and exported the magnitude symbology as a layer file. (One minute.) I opened ArcScene, added the shapefile, applied the layer symbology, set the base height as “[Depth] * -.1″ (using negative to make the points drop below the surface), added a country layer, and set the countries as hollow with a black border. (Two minutes.)
In 10 minutes, I had a banquet of STEM lessons before me. I spent the next 10 minutes just looking at the pattern from all angles. Then I created a short animation and exported it to a 50mb .avi video file, which I converted (via a third party video tool) into a video posted on YouTube.
One challenge with GIS is the wealth of subjects that can be addressed and the infinite directions in which each can be pursued. Education means learning from experiences around you. The Chilean quake has been described as 500 times more powerful than that which devastated Haiti. What can be learned from this about zones of susceptibility, building codes, and preparedness? GIS is a tool through which educators can generate powerful STEM lessons that can help learners of all ages build a better tomorrow.
So we start a new decade. Can you remember what were things like at the start of 2000? Y2K, ArcView 3.2, Windows NT4/98/2000/ME, MacOS9. Hard drives were modest, RAM was expensive. Data were available, if you knew where to look and how to cope with the different formats, but often involved some struggles. GPS was available, but devices weren’t available everywhere, and selective availability limited civilian accuracy to about 100m.
We’ve come a long way. Maps are almost ubiquitous. Computers have exploded in power, but shrunk in size. Operating systems are … well … still evolving. And GIS? Same here — more power, still evolving.
What hasn’t changed, though, are the fundamental concepts and skills of GIS. It’s still pretty much about using the power of the computer to explore layers of data, isolate specific questions, seek relationships, solve problems. There are still floods and fires, and land claims and precious resources, and routes and stops, and countless problems to solve. The galactic capacity of GIS seems to be exceeded only by the infinite capacity of people to say “Well, ok, but now I have a different question …”
Look at the two screenshots above. Though about different topics, with different tools, and separated by a decade between construction times, they still point to what is unmistakable about GIS: It affords the user the chance to look at information in new ways, to look for patterns and relationships, to present a story to others and ask them to share in the analysis in search of common ground, to see the power of critical thinking, and grasp the many ways in which geography matters.
I don’t know what the coming decade will bring. I lie awake at night, sometimes, wondering about our fate. But I take solace in the intensity with which brilliant programmers are working to provide us ever better tools for exploring our world, and the unbridled passion with which many educators are showing children a map and asking “What do you see?”
- Charlie Fitzpatrick, Co-Manager, ESRI Schools Program
I first used the online geology viewer to explore. To dig deeper, I brought the fault lines into ArcGIS Explorer, and was immediately struck by their predominance in the north and west. Is this because the geologic layers are more exposed and observable there, or is it because the geologic layers in the south and east are younger with insufficient time to be faulted?
I then brought the data into ArcMap. The BGS layer file contains symbolized faults, dykes, surficial geology, and bedrock geology. I zoomed to one of my favorite places—Beachy Head, in East Sussex, the highest (162 m) chalk headland in England, inserted a hyperlink to a photograph I took there during a Geographical Association conference, added base imagery from ArcGIS Online, and bookmarked the area. What is the surficial and bedrock geology of the famous chalk cliffs?
I also examined a place I have always wanted to visit—the Giant’s Causeway in Northern Ireland, an area containing over 40,000 interlocking hexagonal columns of basalt. Sure enough, the rocks there are Palaeogene mafic lava and tuff, according to the bedrock geology, while surficial Quaternary till is absent. Why is this absence a good thing for the Causeway?
I encourage you to investigate these new BGS resources in your courses, via the new lesson in the ArcLessons library.
- Joseph Kerski, ESRI Education Manager.
My blog last week was about GIS as a “powertool for STEM education.” In preparing for GIS Day, Geography Awareness Week, and the Virginia STEM Education Conference, and bearing in mind the recently released federal funds for education known as “Race to the Top“, I decided to explore Virginia’s school districts.
The general challenge in STEM education is for students to be problem solvers using technology … to see a situation, identify a question, explore it scientifically, analyze it mathematically, and develop a model that explains the topic or solves a question. My question was a simple one: What is the population covered by the different school districts in Virginia?
With a question established, I sought a relevant data set and evaluated it for trustworthiness. I decided on Census tract population density from 2008, in ESRI’s Data & Maps for ArcGIS 9.3.1. I chose a classification scheme and symbology, projected the display to reduce spatial distortion, and added a background context layer from ArcGIS Online. Finally, I overlaid the map with school district boundaries, after selecting Virginia’s from a national set and clipping off the water areas.
In less than a second, even with a flash glimpse of a re-sampled image, you should be able to see a pretty striking pattern. There are pockets of high density and broad swatches of lower, even minimal density. This leads instantly to a whole set of new questions: Does the school-age density map look the same? Which areas are expected to grow the most? What issues vary in significance for districts with higher versus lower population density? What differences in opportunities exist for students, or educators, because of population? Does graduation rate vary with population? What environmental characteristics affect students in one zone versus another?
Students sometimes struggle to generate questions about a topic. When I was teaching, it seemed to me that, if they couldn’t ask a good question, they just didn’t have a context within which to fit the subject. When we pulled out maps and began exploring, and especially when we began working with data and analyzing it, the questions flowed in a torrent. Class periods spent exploring and analyzing these questions led to a strong grasp of content.
Educators who use GIS well have been doing “STEM education” for a long time, even in classes that may not have had one of the STEM words in the title. Think of how much STEM education could happen if educators were to engage GIS across the grade levels and subject areas. Think how engaged and prepared our students could be!
- Charlie Fitzpatrick, Co-Manager, ESRI Schools Program
My dad golfed over 200 different courses over a 30 year span. Sadly, his skills did not transfer to me, though I acknowledge in a movie I filmed on the driving range [TouTube video] that golfing is a spatial sport. Class discussions about golf courses can include debates about their pros and cons, water resources, land use, permeable surfaces, wildlife habitat, tourism impacts, distances and angles, and much more.
What is the spatial distribution of golf courses in the USA? I found a golf course layer package on ArcGIS Online that I brought into ArcMap. After adding states and countries map layers, I was not surprised to find the high density in California, the northeast, and north central. However, I found a surprising number in Guam, Puerto Rico, and the US Virgin Islands, and Montana’s clusters were surprising to me.
I packaged up these layers and saved them to ArcLessons so that you can use them right away.
Work with GIS fosters critical thinking skills, including questioning data—where it came from, why and when it was created, and other questions. After mapping golf courses, I noticed obvious gaps—no courses in Alaska and only one in Wyoming. I then checked private companies (Golflink and others) and organizations (the Wyoming Tourism Council), and found anywhere from 50 to 70 golf courses listed for Wyoming, and at least 15 in Alaska. I also have a difficult time believing that the Minnesota-South Dakota and Iowa-Missouri state boundaries have the impact that the map indicates on the distribution of golf courses. If most of the golf course data indeed came from the Geographic Names Information System, these only include golf course names that appear on USGS topographic maps. That most USGS topographic maps are dated and that many golf courses are simply not on topographic maps might explain some of these gaps. Check your data sources. Today, with web sites hosting spatial data rapidly expanding, it is more important than ever to understand your data—its benefits but also its limitations.
In a recent ESRI EdCommunity blog, I described how to download and use a script to create cartograms in ArcMap. While I examined total CO2 emissions by country, the same tool can be applied to any data at any scale. Because I consider cartograms to be an excellent research and teaching device, I then examined a historical county data set from 1900 to 2000. I was interested to see what cartograms would reveal about historical population trends for specific areas and discovered that they serve as a springboard for discussion about the forces responsible for such changes.
I created a cartogram for the past 100 years for Colorado. I joined the resulting cartogram feature class with the original data on the field “ObjectID” so that I could examine the population attributes. The maps comparing 1920 with 2000, below, show differences and similarities.
As expected, Denver County dominates in population each year. Was it natural to locate the state capital there, or did its capital status encourage subsequent population growth? Denver’s population, at 256,000 in 1920, doubled to 527,000 by 2000, but the state population more than quadrupled, from 939,000 to 4.3 million. Consequently, the cartogram’s “area” represented by Denver’s population decreased from 47,000 to 32,000 square kilometers as Denver’s share of the state total dwindled from 27% to 12%. Pueblo and Weld also decreased in relative size between 1920 and 2000, but for different reasons. Pueblo County’s share decreased with the decline of its iron and steel industry. Weld County’s share decreased due to the rise of agribusiness until 1980, but then experienced rapid suburbanization along with much of the High Plains. Agricultural counties outside of this zone decreased in size on the cartogram and in absolute population, evidenced in the shrinking of counties like Cheyenne and Prowers along Colorado’s eastern border. Also noticeable is the rise of suburban counties such as Douglas, Jefferson, and Arapahoe.
What do you think your state will look like over the past 100 years? Use the cartogram tool to find out!