Pros and Cons to OpenStreetMap

OpenStreetMap is a map of the world, created by people like you and free to use under an open license.

That’s OpenStreetMap’s (OSM) opening lines to their free-to-anyone spatial database.

Yes. You read that right. Free spatial data!

If you’re looking for spatial data you can’t get from an authoritative source (i.e. city, county, state, or federal agency) for free, then OSM data may be worth using, especially if you’re working in a part of the world where getting local data would be difficult due to language barriers or just simply there is a lack of data.

But before you do so, let’s go through the pros and cons of this popular spatial data source.


  1. It’s free! Complete and truly free to use. You can download a whole world of data (approximately 803GB as of June 2017) by snagging the weekly copy of Planet.osm. Once on your computer, you are free to do with it what you like. Load it into a QGIS or ArcMap document and symbolize as you see fit. You can even edit the data. It is truly all yours.
  2. Related to the first point; the data comes with no strings attached. When you read my first point, you may have thought: “What’s the big deal? Google Maps, Bing Maps, and other web map services are free, too.” True, but Google Map data is *not* available for download. You can contribute edits to Google Maps, but that doesn’t mean Google will give data back to you.
  3. OSM often has richer data than other free map sources. For example, someone might have digitized all the hydrants in your city. Or all the best dog-friendly businesses. Or, if you are like me and ride your bike everywhere, all the barriers a bike-rider might encounter when getting around town.


  1. Data quality is spotty. Because OSM depends on volunteers, literally located all around the wold, data quality and consistency is haphazard. In places where a community of local mappers make a concerted effort to improve the database, you can get some stunningly detailed and accurate base maps (i.e. San Francisco area).  Where they don’t…well, let’s just say, you get what you pay for.
  2. Very little, if any, metadata is associated with OSM layers. Are the bus routes current? Who knows.
  3. Data is not authoritative, obviously. In the United States, OSM’s road network was derived from U.S. Census data. So on the national level, the road network is fairly accurate, complete, and authoritative. You can rest assured that the data went through some sort of data quality check with the U.S. Census and comes with a statement of accuracy. However, most other OSM layers are not. While someone may have digitized every tree in your town’s parks, there’s no way to tell if they accurately identified a walnut tree from a spruce.

In a nutshell, OSM data is great to have when you’ve got nothing else. Even when you do have access to something better, you may want to download the latest OSM layers. For example, I’ve used OSM’s building outline layer for the San Francisco Bay area, because, frankly, those industrious volunteers have already merged the nine SF Bay area county databases for me.

Another great reason to use OSM is that they support mapping efforts throughout the world. With their Humanitarian OpenStreetMap Team (HOT), they even try to help folks with efforts like their Malaria Elimination Campaign. While some tech companies claim to do no evil, HOT actually does.

Here’s a nifty info graphic of the Pros and Cons to OSM.

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We recently moved to Rohnert Park, a small (north of San Francisco) community of roughly 41,000 people.

I love it here. The town is bikeable and walkable. By bike, I can get to the local grocery store in less than 10 minutes and to my bank in less than 15.

And in less than 20, I can walk to Cotati’s newest SMART train station.


SMART Train at the Rohnert Park train station 6-29-2017

The Sonoma Marin Area Rail Transit (or SMART) started special service this summer, transporting folks from Santa Rosa to San Rafael. Though a start date for full, regular service has yet to be announced, if you were lucky, you might have managed to snag a ride during one of SMART’s free ride days.

On the first day SMART was open to the public, I wasn’t so lucky. But I still wanted to take the ride down to San Rafael. So, I decided to do it virtually – via a map.

Go ahead – click on it! You know you want to…

Of course, I had to add some spatial analysis and data.

Using both ArcMap Desktop and ArcGIS Online geoprocessing tools, I determined a (driveable) 5 minute service area around each currently-to-be-opened station and then added some basic demographic data to those areas (shown in green blobs, dark shades indicate a larger population served).

The summary tab at the bottom tallies the total potential population served (within 5 minutes of each station), the average household income of that population, and averages the population diversity index (the larger the number, the more likely two random folks are not of the same race).

Feel free to zoom in and explore the map. It’s interesting (to me, at least) to see the difference of service areas surrounding each station. For example, Rohnert Park’s 5 minute service area is smaller than Cotati’s (presumably because it’s faster to get around Cotati than Rohnert Park). This leads to a lower population served by Rohnert Park (9,873 people) versus Cotati (29,449 people) even though they are only 4 minutes (1.24 miles) apart.

Some thing tells me the Cotati train station might be more popular than Rohnert Park’s station.

Until we all get a chance to ride the train, what other insights might you find on this map?


2015 in Review

The new year is only a couple of days away, and I thought it would be a good idea to review all the projects I worked on in 2015.

But instead of doing an article here, I utilized ESRI’s Story Map templates to walk you through all the places I’ve have the opportunity to work in.

To be honest, I didn’t go to all the places listed in my story map. For most, I simply created maps from the comfort of my home office. But I had the chance to visit Ethiopia (twice), Kenya, and Chile this year. And though it wasn’t for work, my husband and I visited Pacific City, Oregon as well.

How I Did It

In case you were wondering, utilizing ESRI’s Story Maps is fairly simply, but it does require an ESRI ArcGIS Online account. If you don’t have one, you can’t do it. But if you do, in a nutshell, here are the steps involved in creating an interactive story map:

  1. Log on to your ESRI ArcGIS Online account and create a new map. Choose a base map that best works with the data you intend to upload. For example, earlier this year, I created a Censorship on the Internet Story Map. Because of the “dark” subject matter, I went with the ESRI’s Dark Gray Canvas. It features white labels over gray continents on near black seas.
  2. Next, upload your data. You can upload a geodatabase or shapefiles, but your shapefiles will need to be in a zipped folder.
  3. Once the data is loaded, you’ll have to symbolize and configure any data pop-ups. ESRI makes this fairly simple, but if you don’t get it right the first time, you can always change the layer parameters by hovering on the layer name. When the edit icons appear, choose among them to change the symbology or functionality.
  4. If you are happy with how your map looks and functions, the next step is to save the map (title it, add tags, and describe the map) and set the sharing option to public.
  5. To create a Web Map, you can do this several ways and you can even create a Web Application (similar, but different). But for now, let’s keep it simple. With my project story map, I decided to host this on ESRI’s account server (my address is I also decided I wanted a simple Story Map that just walks people through the various projects I worked on for each month of 2015. Here are the steps I went through to create my story map:
  6. From the My Contents page, click on the ‘Create’ drop-down arrow, then click on ‘Apps’, and then finally on ‘Using a Template’.
  7. A pop-up window will appear called ‘Create a New Web App’ and it asks you “What do you want to do?” Below that, click on ‘Build a Story Map’.
  8. There are several option here. I went with the Story Map Journal because I like how it combines text, images, and the map in a vertical scroll. I could have went with the Story Map Tour, but I don’t have images for each of my projects other than the maps I created themselves, which I don’t want to share (because of client confidentiality concerns).
  9. Once you click on the template you want to use, you have a choice. You can either host it on ESRI’s server – the ‘CREATE APP’ option – or ‘DOWNLOAD’ the template html and javascript files and host it on your own server. I’ve done it both ways. Each is fairly simple to use, however, I like hosting it on my ESRI online account because then I can manage all my web maps via one interface (rather than keep track of the backend stuff on my server). So, for this exercise, I chose to ‘CREATE APP’.
  10. Fill in the title, tags (these help folks find your map), a summary of what your map conveys, and then specify where you want to save it (depending on how you have your account organized, just use the default account folder). You can use the same info you entered when you created your online map above.
  11. Once you click ‘DONE’, you are taken to the online Map Builder. Depending on which template you chose, you’ll be presented with several options. From here on out, it is fairly intuitive, but can get complicated. This is your chance to create your masterpiece! Take your time and utilize photos. You can save your work any time and no one sees anything until you make it public. For this story map, I went with a Floating Panel, I chose to use the online map I created above as my “main stage content”, and I customized each location based on the month I completed a project. Then I added text and pictures in the side panel. Alternatively, you can start out with an image or video. Get creative and make a story map that entices and intrigues by, well, telling a story!


Click through to visit the interactive map. You’ll get a chance to virtually travel the world with me.

Thanks for reading and Happy New Year!

Show Off

I don’t often get a chance to showcase my work.

As a consultant, much of what I do is confidential. However, at times, I get the opportunity to work for a non-profit or on a public project, and that means I can share.


Recently, I was approached by Friends of the Gualala River (FoGR), to create a few maps of the planned timber harvests adjacent to the river in northern Sonoma County, California. The challenge was to quickly and effectively show the currently planned logging areas with those that had been conducted in prior years.

The maps that accompanied the timber harvest plans looked something like this:

Portion of original timber harvest plan map (courtesy of CDF, 2014).
Portion of original timber harvest plan map (courtesy of CDF, 2014).

Serviceable, for sure, but the maps had a lot of data, were very hard to read, and it was difficult to determine context.

So, I was asked to take just a few key components of the map, and create something more visually appealing, and give a better sense of where the units were in relation to a seaside community and adjacent parks.

Here’s the result (you can click on it for a bigger version):

Created for FoGR, DMS, 2015.
Created for FoGR, DMS, 2015.

To be fair, I didn’t have to include as much information as the original map. The focus was to highlight the adjacent community and provide an aerial for context. Everything else was disregarded. I think it looks alright. What do you think? What would you have done differently?

To see more, visit FoGR’s post on the project.

Airports and Trails

Another project I recently got a chance to work on were the trail development options at the Truckee Airport District in Truckee, California.

Truckee Airport Trail Option map, DMS, 2015.
Truckee Airport Trail Option map, DMS, 2015.

The goal of this map was to show the trail development options in relation to the surrounding trail system and possible connection points.

Neither of these project were technically challenging, but it was nice to just create something that met my clients’ needs and I could share.

Story Maps for All

While I appreciate a well-designed paper map, there’s no denying that most folks hangout in the internet more often than not and rarely do we print stuff out anymore. So, why not do the same for our maps?

For the two projects above, I create two simple ESRI Story Maps:

  1. Gualala River – Proposed Timber Harvest Plans
  2. Truckee Airport District Trail Development Options

Story maps are interactive maps that use narrative (and sometimes pictures) along with a map to highlight a problem or solution. While I didn’t use the Story Maps to their full-potential, I hope from these simple examples you can get a glimpse of their potential.

If you would like to see more cool maps, check out the Interactive Web Maps link list to the right (if you’re on a desktop) or scroll down to the bottom of the page (if you’re mobile).

Historic Landmarks Web Map


GIS Day 2014 is coming up, and in preparation, I set out for myself to create three web maps.

The first is a map showing the twenty-seven historic landmarks in Sonoma County. Below is a screen shot of the web map as viewed in Google Chrome. It has some nifty functionality such as the bookmarked Zoom locations, a nice grid display of the features on the left-hand side of the screen, and when you click on a point, you can drill down for more information on each locale.


I utilized ESRI’s Shortlist story map template which can be downloaded here. It was quite simple to make and didn’t require any specialized software what-so-ever. You do need an ArcGIS Online account. Go here to create one.

My next two projects utilizing ESRI’s templates will be more complicated and feature derived data products. Those should be fun and I’ll keep you posted once they are completed.

On a separate, but related note, did you notice I mentioned GIS Day? It’s coming up. Like, in about two months! For those of you in the north San Francisco Bay area, mark your calendars (November 19, 2014) and get ready for a fun and educational day at the Finley Center in Santa Rosa, CA.


Field Day

For those of us stuck behind a computer, it is always nice to get out in the field every now and then.

Last week, I had the pleasure of attending the North Bay GIS User Group‘s Field Day meeting where four great companies featured their data collection (and dissemination) tools. I thought I’d do a recap just so that I would remember all the cool products and stuff I learned.

There were four presenters at this year’s Field Day: Mapistry, Canogle, Sonoma Land Trust, and TopCon/Engineering Supply Company.


mapistryI met Ryan Janoch, CEO of Mapistry, a new cloud based mapping software. He said he started his company for one reason: so you could do one thing: make a simple map – quickly.

Now, while I have tons of experience making quick, meaningful maps with sophisticated software like ESRI’s ArcMap, others do not. Nor might they have access to that fancy software and a ready database.

No, instead, project managers, specialists, report writers, whomever often have to rely on that one GIS Specialist who’s endlessly busy and pulled in a thousand directions to make their map happen. If you have me on call (which you can, you know, call me), then you have nothing to worry about. I’ll take care of all your mapping needs. But if you don’t have me and all you want is to create a simply map with a few points on it, check out Mapistry’s online service. At the moment, it is free and it just might meet your needs. Plus, you can use it to collect data out in the field.


For those of you on a tight budget, Canogle might be a service out of your league. However, as part of an integrated trail interpretive project, this might just be the thing you are looking for.

Have you ever been walking along a trail and reached one of those wooden boxes that are supposed to contain some interesting facts and/or history on a place only to find that it’s empty or a pack-rat has taken all the brochures and turned it into a nest? Cute critters but you’re out that information. While I’m often left feeling richer after a hike, leaving one of those interpretive sites without the information always makes me feel like I’ve missed out on something.

Wouldn’t it be cool if you could pull out your phone, click a button, and the voice of information fills you in on all you might have missed?

Well, that’s what Canoge can do for any trail. If you manage the interpretive programs for a park, reserve, or any land with interpretative trails, check out what Canogle can do to augment all your great interpretative programs. They provide a service and mobile application that will integrate a map and interpretative information, either on the go or pre-downloaded so all your tech-savvy hikers will never miss a single fact.

Open Data Kit

Joseph Kinyon, GIS Manager for the Sonoma Land Trust, came out to show off all that he’s done with the Open Data Kit (or ODK) suite of mobile mapping tools. Anyone with a bit of time can customize this free software to create data collection forms, upload it to a mobile device for on-the-go data collection, and aggregate the collected data on a server.

The major advantage to this open source software is that it is free. You can use it on any device and you can create data entry forms that are meaningful and pertinent to your project.

The biggest draw back?

It’s not exactly (low-tech) user friendly. If you have some coding experience, you can be up and running in a week. If not, then you are not likely to try this. But for the adventurous (and broke), this is a tool you might want to consider if you are willing to accept the variable accuracy of whatever mobile device you load it on to.

Mr. Kinyon’s example of recording roadkill (yeah, there’s meaningful data in roadkills!), I was impressed with the complexity and ease of use of the tool. I might be using it myself in future projects.

TopCon – Engineering Supply Company

Last, but not least we had a representative from Engineering Supply Company come out to show off a few of TopCon‘s latest GPS/data collection products.

Yes, I drooled.

GMS_2_webI’ve long wanted to upgrade my 10+ year old Trimble Pro XRS unit (a great unit, but it is just too big and heavy for my current needs). And though I’ve drooled over some of Trimble’s latest offerings, their sticker price has often squashed my appetite for a new unit. I figured since TopCon provided pretty much the same great GPS product (almost the same color!), I thought their prices were the same. I wasn’t given a definite price on the spot, but it seems TopCon’s price ranges sounded a lot more palatable than I had previously thought.

I especially liked the GMS-2, a small, handheld, meter-level accuracy GPS unit. It has an integrated photo capture tool and the on-board firmware seemed much more intuitive than TerraSync. Might Christmas come early for Digital Mapping Solutions?


If you have any questions about any of the products featured, please ask or click through the links above to visit each vendor.

Thanks for reading.

Web Maps

As much as I love me some paper maps (see my previous post), most folks do not use them nearly as much as they used to.

I know I don’t.

With a smart phone in hand, there really is no excuse to scramble through your glove box looking for an out-of-date map. Or stop at a local store and buy a city map. For good or bad, the world we live in now includes digital maps.

And while those of us old-timers still appreciate a well-designed, ‘real’ map, web maps can do so much more.

You know how to access a web map. Those are everywhere and most of us have used Google, Yahoo, or Bing maps* to navigate our little slice of the world. But what if you wanted to show your data? How do you harness all that open-source goodness to show off your projects?

Google Maps

The ubiquitous Google provides the use of their map engine through the Google Map API. It is quite simple, and because of the proliferation of Google Earth (a desktop application), the data format widely used with Google Maps (.kml or .kmz) can easily be created or exported from many standard GIS software packages. Heck, if you are careful, you can just type the .kml file yourself. It really is that simple.

You’ll need several things to get started:

  1. Your data in .kml or .kmz format,
  2. A web page where you want to place your web map (and administrative access to that web page),
  3. A specific API key from Google,
  4. Time to write a bit of code.

That’s it. Once you have all those things in place, I guarantee you’ll have a map just like this one up and ready to go:

EDIT: Oops! I changed over to a new server and my JavaScript pluggins are on the blink. I will update soon!

Regardless, if you want to find out more on how to work with Google Map APIs, check out this site for a quick tutorial.

Open Layers (with GeoExt)

With as simple as Google Maps are, why would you not use it? Why are there so many other options?

One thing that Google likes more than anything else in the world is data. Specifically, your data. If you read the fine print when you sign up for a Google API key, you’ll see that once you accept their terms, your data is pretty much in the hands of Google to do as they please. Some folks may want to share their data that much.

For those folks unwilling to give Google full access to their database, there is Open Layers.

Open Layers is an open source API that allows anyone to use their base data as well as port over Google and Bing base maps. All for free. They do not require an access key. You have control over the javascripts and load them directly onto your website (rather than reference an online version as with the Google API), so you need never worry about a broken link because the API got upgraded. And it is just as simple to use as Google Maps.

You can check out quite a few examples here. As you peruse the simple examples, keep in mind, you can go a step further with Open Layers and use GeoExt. GeoExt, also open source, couples Open Layers with ExtJS, allowing for more customization.

If you want a more extensive tutorial on Open Layers visit Erik Hazzard’s site here. To find out more about GeoExt, just go to the source and start learning!


I just discovered Leaflet and I am quite impressed with what I’ve seen so far. Developed by Vladimir Agafonkin, an artist, the API’s look and feel is different…and maybe even better than Google Maps. That’s primarily because it is using OpenStreetMap‘s base maps that tend to use more vivid colors, but the coding does have some nifty short cuts that the other API’s just do not have (like adding map features with associated data with one line of code).

One thing to note, the API does relies on the Leaflet map script placed in the body (not the header) of your html as well as additions to your CSS. Just keep that in mind when building pages into automated coded websites (like any WordPress hosted site).

ArcGIS Online

For those of us who use ESRI products, ArcGIS Online feels like a home away from home. The terminology is similar to what we are used to and there’s very little file conversions we have to do to our geodatabases, shapefiles, and rasters. But, it is not as straight forward as the other examples listed above. Though you don’t need an ESRI license (at any level) to use ArcGIS Online, your options are limited without an ArcServer license. In addition, you are at the mercy of ESRI’s geoservers which can be slow for the likes of you and I.

Regardless of its drawbacks, ArcGIS Online provides a nifty platform to share you data, giving you access to cartography and analysis tools not available in most web mapping tools. You will need an ESRI global account to start, so I suggest signing up for one (it’s free). Once you’ve done that, create your masterpiece over on the ESRI site, then it is just a matter of embedding your map with a very small snippet of html code. Like this:

View Larger Map

(Yes, it takes a while to load.)

But! No Javascript necessary. The map is interactive (click on a line and get instant data). And if you click through on the ‘View Larger Map’ link, you’ll be taken to ArcGIS Online where you can explore much more.

Speaking of Much More…

Did you think that was it? There are many more web mapping options out there, but the above examples should get you started on simple web projects no matter your budget. If you have any questions on how to get your web map started, I would be more than happy to help.

EstherArt_BlkWritten by Esther Mandeno, owner of Digital Mapping Solutions

*I’m sure there are more commercial sites offering their map services.