North River Geographic Systems Inc

Spatial Problem Solving

Cartography

I’m making a Map: Location

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I should write something. My last few “2020 in Review” posts aren’t working like I’d wish – so I sat down last night to make a map.

A map of what? Good question. I think in my every day attempts of databases and technical wizardry I lose sight of “I actually like maps” and I’m not the best at it. Given my background I should be better. I decided to make a series of maps on “things I like”: Canoeing, Hiking, Bike riding, etc. So my first shot is a canoeing map. A very simple map of something I like to do.

The location is easy – The start of the TN River Gorge. It’s a great 8ish mile paddle. Simple. Quiet.

canoe
Looking into the Tn River Gorge

My first thought was to do what I normally do and just drape things over a aerial photo. I’ve decided to make it a bit more fun and not go that route – This may end up being Black and White. I’m also going to stick to two sizes of paper in this series of maps. Either 8×11 or 11×17.

When you canoe this loop – you start north and head south and loop around an island and then head back north again. The first half is all upstream (heading south) and the last half is all downstream (heading north). Bonus it’s all NW-SE trending so it will need to be rotated.

I start building it in QGIS with some aerial imagery and Hillshades for fun:

QGIS Canoe Map setup

If I make a 11×17 layout it looks more like this because I’ve added 120 degrees of rotation:

QGIS canoe map setup

As I sat here I had a question. I scale it. I generally start to get an idea of “what” I want. I know the extent of the map but can I get the extent back into QGIS so I can start clipping things and not having to include 500 square miles of stuff for a map. I could just set up the boundary back into QGIS as delimited text (make points -> draw polygon). I could just “eye ball it” which is how I do about everything from Jeep repair to Home Repair.

For fun I searched the tool box and….Print Layout Map to Layer

I run that and……I know where my map falls in the main window. So I can buffer it and start clipping data.

Why even post….I had no clue this tool was even here. My next map (another canoeing map) will be a bit larger than 11×17 so I’ll nee to use Atlas to setup 2 to 3 pages. I now have the general extent for 11×17 at X scale, copy and past this boundary a few times, and rotate it to get the general layout locations I will need

Map 1 is well on it’s way to happening. This is a bit therapeutic and that’s something I need at the moment.

 

 

Virtual Layers and Bike Data

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To badly quote a Queen Song, “I like to ride my bicycle”.  I’ve been trying to find new spots to ride. Of course being me I’m always debating things I can map while I’m out doing something.

This weekend I decided to map the Bike Share Program. It was raining so I went with a combination of windshield survey, bike riding, and internet searches to locate the Chattanooga’s Bike Share locations. I have a long standing history of being wrong about everything. When the bike share program started back in 2012 I shrugged and went “this won’t work” and 6 years later we’re got 40ish stations (I counted 40 and the internet tells me 41) and over 400 bikes. All the bike shares have a printed map and Chattanooga’s open data portal has a CSV of old bike locations.

Here are the 40 bike share locations in Chattanooga. I’m hoping to stick this in OSM and on the Open Data Site for Chattanooga.

OpenStreetMap Chattanooga

I had read about Anita Graser’s Flow maps recently.  One thing I notice when I’m out is how many places I see these bikes. Where do people come from and where do they go? Digging around on Chattanooga’s Open Data portal I found travel information that was slightly out of date but provided enough information to make this fun. The data gave me two things I needed: bike check-out locations and check-in locations. I know now people leave from Point A and end up at Point B.

Lets create a virtual layer from the table of information and the point layer. Trips being the table and Locations being the points:

SELECT StartStationID, EndStationID,
make_line(a.geometry, b.geometry)
FROM trips
JOIN locations a ON trips.StartStationID = a.id
JOIN locations b ON trips.EndStationID = b.id
WHERE a.id != b.id

I created what I can only describe as “hub lines” of the Bike System:

That doesn’t really tell me anything. It does show me the power of a virtual layer. A virtual layer is an area of QGIS I’ve not touched much – but in short it’s code  tossed against a dataset and that code creates a new layer in QGIS. In this case I’m using functions in QGIS with some SQL code to render the lines. The lines act like physical data.

I refined the code a bit to only show one bike share. So where do people go that leave from the “main” spot (1299) at Outdoor Chattanooga?

Now that we’ve got fewer lines, things are more interesting. First off I don’t have data for all the stops – hence the dots with no lines. The second part I notice is some people go as far as they can go on a bike. They go to the farthest station. The Bike Share Program is “transportation” now on the same level as a bus but in just a smaller area.

Lets pick at it some more and do this:

Select EndStationID, count(*) from virtual layer group by EndStationID

That tells me the counts of where are people going from 1299. Not surprisingly from this location the #1 destination is this location (1299). People come back to where they rent the bike. The next two stops are “the scenic” bike share at 1319 and the bike share that connects to the free shuttle program at 1303.

The least used one is unsurprisingly 1329. That one is located not quite near the college campus and not quite near anything useful for day to day living. There’s really no reason to go there unless you’re lost or going to the Walker Theater for a concert. 1329 may be at the highest “spot” in the city or at least close to the highest (i.e. you have to ride uphill to get there from anywhere).

My next big question: Is it all connected with bike lanes? That data doesn’t really exist except within OpenStreetMap…and it’s outdated. It may exist somewhere in the city but I’m not sure where. My next mapping fun is finding a source of bike lanes for the city. I will probably make my own.

So what did we learn?

  1. If you come to Chattanooga use the Bike Share (and wear a Helmet)
  2. Virtual layers are pretty powerful and I really only did one thing – but it was a powerful one thing.
  3. OpenData for your city is your friend. I will most likely hassle someone for an updated CSV for the city bike share program.

Go out and make a map….and ride your bike.

FOSS4GNA 2016 – First Post

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It’s over.

As one friend pointed out there are something like 4 stages of conference attendance:

  1. Go for the Tech
  2. Go for the Friends
  3. Go for Free Beer
  4. You Stop Going

On most everything I’m at 4. It takes a lot to drag me to a conference these days. I think my most attended conference is the Georgia URISA Conference. I’ve made three FOSS4G Conferences. For FOSS4G events I’m still at a 1 and 2.

There’s going to be several blog posts over the next few days on the conference. I can’t cram all my thoughts into one post. Plus my posts have been getting longer and longer and I really want to shorten them up a bit.

I’ve made the conferences in 2013, 2015, and 2016. Each one gets a little bit bigger…..BUT – each one has the same community feel I’ve missed elsewhere and enjoy. It really doesn’t matter who is the super star rolling into this conference – you’re going to have the same good group of people finely arrayed from business casual to “Well Day 3 for these Cargo pants”. You have people who really get don’t enjoy crowds and then you have the people who can command a room full of people. This conference accepts all kinds and it’s nice. It’s refreshing. It’s the way GIS should be.

We were somewhere around 550 strong for FOSS4GNA – which if you noticed there was also the ESRI SERUG or whatever conference running at the same time during this event. Overall – didn’t hurt us a bit. In fact – ESRI – please plan competing ones from here on out. It actually may have helped.

If you haven’t been to a FOSS4G Event you should go. This is coming from a guy who is at a 4 for everything. You will meet friends, you’ll learn something, you will walk away refreshed (and a little tired).

Like I said – more posts coming shortly. This was my get up and “stretch and warm up” post for the rest of this week.

Just in case you’re debating going to something:

foss4g-logo

BOSTON

 

Map Competition for Georgia Students

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…and from Georgia URISA:

Hello Students!

Announcing our

“Online Map Competition”

This map competition it is an opportunity for Georgia University/College students to share their best maps with others who appreciate quality cartography, innovation and finally get recognition for their talents.

This is an online competition.  All maps/poster and links need to be submitted by midnight of May 10thto  urisaonlinemapcompetition@gmail.com with a minimum half a page statement that provides context of the submission, i.e. its purpose, how it may be used, how it was created etc…, and a cover page that will include:

  • Student information, including name, address, phone number, email address.
  • Degree program (e.g., M.A.), cartography/GIS instructor’s name.
  • Graduation Date
  • Institutional affiliation

Maps will be judged based on the following:

  • Standard Map Elements: Title, legend, scale etc: 15 points
  • Balance and Layout: Does map appear well-balanced to the eye? Are some areas of the map blank while other areas are crowded: 10 points
  • Drafting Technical Quality: Technical involvement; difficulties: 20 points
  • Detail Thoroughness: Is there too little detail? Is there too much detail? Does it extend into every passage? Is it consistent throughout the entire map? Is the detail easy to understand or is it confusing? Does the detail match the legend or the list of symbols? What would be the use of the map? Does the map show the purpose: 15 points
  • Visual Impact: Does the cartography make the subject interesting or boring? Overall, does the map look good: 20 points
  • Innovations, new methods which enhance the understanding of the map: 20 points

 100 points is a maximum that student can acquire based on above requirements.

First, second and third place will receive a prize. Prizes to be announced soon! The rest of the participants will get recognition in the URISA newsletter and “swag.” 

Maps need to be submitted by Midnight of May 10th to urisaonlinemapcompetition@gmail.com, confirmation email will be an indication of the submission.

QGIS: The Label toolbar

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You’re sitting in a class…..back up – You’re teaching a class and and someone goes “Hey – there’s this QGIS Label Toolbar. How do it work?”.

I’m probably better at making a map than I believe. I really don’t enjoy it because with every map Green was always a problem. “Can you make this green ‘greener’?”. I would get upset and go “OK” and immediately make it too green. Way back in my career I was working on a Spill Plan Prevention Control and Countermeasures map (I think that’s SPCC). This map was all manual back in the day. We had a plan to make it “digital”. So we scanned a photo (and didn’t georeference it) and started laying out ArcINFO Annotation on it. At some point we scanned another map and had to move everything (not georeferenced) again. Then at some point we decided georeferencing the map was a good idea so I had to move all the annotation. Again. Anytime you say “label this feature” I break out in a sweat to this day.

So I sat this weekend with the whole goal of making the QGIS Label Toolbar Active. The best I could do was this:

Selection_395

I finally “Read the Manual” and found that the label toolbar is Attribute based. So if I add some Attributes to my data layer:

  • x – decimal number – Length 12 Precision 3
  • y – decimal number – Length 12 Precision 3
  • rotation – decimal number – Length 12 Precision 3
  • visibility – integer – Length 1

…..and then I assign those attributes to the label properties:

 

Selection_010 Selection_012

…..and then I edit my layer:

Selection_009

I can now move my labeling all over the place to make a better map. I can turn labels off. I can rotate the labels. Of course I’m not even discussing the Rule based labeling and all the joy you can have there.

Anyway – I left a tutorial I need to clean up a bit over HERE that should at least get you started.

 

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