Tuesday, June 14, 2016

Reducing Shadows in Landcover Classifications Derived from Near-IR NAIP

Over the last few years I have produced several high-resolution land cover classifications using the excellent 1-meter resolution 4-band NAIP orthophotography available from the USDA APFO.

For the most recent classification I used the 2015 4-band NAIP to produce a landcover classification of the Hylebos Watershed for EarthCorps, who have been actively restoring riparian areas and wetlands in the watershed. They are planning to use the landcover for a  variety of analytical and prioritization purposes. Unfortunately, the sun angle at the time of image acquisition produced a lot of shadowed areas, which reduces the usefulness of the landcover data.

Original 2015 NAIP

Preliminary landcover classification--note large areas of shadow within forested classes

In order to fix this, I tried a new approach:  extract the shadow class, mask each of the bands to the shadows, and run an unsupervised classification using isocluster (the original landcover classification was produced using supervised classification on six bands, to learn more please see this excellent slide deck produced by Chris Behee). Here is the extracted shadow class, followed by the masked NDVI:

The extracted shadow class

NDVI within shadows (greener = higher photosynthetic activity, redder = lower photosynthetic activity)
The isocluster output generated a new set of 10 classes, three of which represented forested classes.

Output from isocluster on the masked bands
 My hope was the remaining 7 classes could be used to differentiate dry grass and impervious surfaces, but the extremely dry conditions during the 2015 summer resulted in very low photosynthetic activity and consequently the remaining 7 classes were highly confused, so they remained as shadows.

The resultant forested classes within shadows were added back into the classification to produce the final product:

Greatly reduced shadows in the landcover classification

Which is a big improvement! Here is a view of the landcover classification within the entire watershed.

Wednesday, May 25, 2016

Mapping Historic Ballard

Yesterday I attended the 2016 Washington URISA conference in Tacoma and gave a presentation called Mapping Historic Ballard with Crowd Sourced Mobile Data Collection to a room full of my GIS colleagues. The slides from my talk are available here and should also be available on the conference site sometime soon. I had a great time at the conference, and as usual came away with new friends, ideas and insights.

The Mapping Historic Ballard project is nearly complete and we will be celebrating the completion of the project on Saturday, June 4 at the Sunset Hill Community Center (more details here).

Here are some preliminary versions of our results maps, taken from the presentation:

The buildings shown on this map are the best of the best--the Select 150 and Vintage 500. These buildings are high-integrity historic structures that provide broad representation of the neighborhood spatially, temporally, and architecturally
In addition to the representative sub-set, we are able to create a variety of maps using the attributes collected during the survey. This map shows buildings by type.

This map shows all parcels by evaluation category.

In addition to the static maps, stats, and spatial data we produced for the project, we also generated a series of interactive webmaps. Below is the map of the full survey--click a parcel to see a photo of the building, as well as a list of structural and site characteristics. (a full screen version is available here).

We built a series of 'time travel' maps that enable users to swipe back and forth between the past and the present day. Here is a screenshot of the map showing 1904/2015, click here for the interactive version:

 1937/2015, click here for interactive version:

1996/2015, click here for interactive version:

My talk focused heavily on the volunteer-driven nature of the project, and I want to acknowledge the tremendous dedication and effort exhibited by the dozens of Ballardites who walked the neighborhood and used their mobile devices to gather the survey data. Here are a few pictures from the first training session and the field survey.

The first batch of volunteers at the training session held at Ballard Library

Kris Royer Collins and Brid Nowlan, gathering data on a chilly February day

Benson Shaw, collecting data and smiling as usual

Friday, February 19, 2016

Eruption: The Untold Story of Mount St. Helens

Last year I had the pleasure of working with local author Steve Olson on his new book Eruption:  The Untold Story of Mount St. Helens, to be published next month by W.W. Norton. I made several maps for the book, and the best thing about working with Steve (from a cartographer's perspective!) is his love of maps and willingness to take a somewhat unorthodox approach to integrating maps into his book. We were able to develop several 3D views that I think worked really well (examples below).

Steve will be talking about the book with Steve Scher at Town Hall on Monday, March 7, and you can get tickets for that event here. For those of you in Portland, he will be speaking at Powell's Books on Wednesday March 9 at 7:30. More info here.

You can pre-order a copy of the book here, here, and of course here.

Here is my advance copy of the book:

Here is one of the maps, as it appears in the book:

Here are digital versions of a couple maps:

Monday, December 28, 2015

10 Seasons of CORE GIS Holiday Cards

Each holiday season for the past 10 winters we've produced a custom card to send to colleagues and clients. I thought it might be fun to post each of the designs, especially for more recent acquaintances who may not have seen the earlier editions.

Here they are, in reverse chronological order.

2015:  Map Drops

2014:  Global Bike Map

2013:  Caribbean Toucan

2012: North Pole Caribou

2011:  Holiday Compass Rose

2010:  Global Seaturtle

2009:  Map Sledding

2008:  Holiday Topo Map

2007:  Christmas Island

2006:  Happy Watersheds 

Monday, December 21, 2015

Friday, June 26, 2015

New STP Map for Cascade Bicycle Club

Over the past year I've been redesigning the route maps for the Cascade Bicycle Club's recreational rides. Most recently I worked on the Seattle To Portland (STP) route map and I got two printed, folded copies in the mail earlier this week. I only do print maps occasionally now (everything is digital and/or online) so it was a real treat for me to see one of my creations on paper.

In addition to the cartography, I also got to do all the graphic design and layout for the piece, which was a real treat.

Here are a few shots of the printed map, followed by digital images.

Tuesday, April 28, 2015

Providing GIS Support in West Africa using Open Source Software

Earlier this month I spent a week in Ouagadougou, Burkina Faso providing GIS support to a research methods meeting of the Collaborative Crop Research Program (CCRP). The CCRP is funded by the McKnight Foundation, and I was invited to work on the project by my friend and colleague Karsten Vennemann who has been working with McKnight for the past few years on a variety of projects.

When I agreed to work with Karsten on this project and told friends and family I would be traveling to Burkina Faso, the inevitable initial response was "Where's that?!?" It is in West Africa, bordered by Mali and Niger to the west and east, and by Cote d'Ivoire, Ghana, Togo, and Benin to the south.
A close up of the locator from one of the CCRP maps. Burkina Faso is the red area.

Ouagadougou is the capital of Burkina Faso, and is located in the center of the country in a region of Africa known as the Sahel, where the Sahara transitions to the forests closer to the equator and the Atlantic coast.
Ouagadougou is in the center of this map; red points represent CCRP project sites (based on data we had available prior to the workshop)

The workshop was attended by 24 CCRP grantees, with two attendees from each of 12 projects located in Mali, Burkina Faso, and Niger. Support staff included Dr. Ric Coe and Dr. David Stern from University of Reading, Dr. Bettina Hausman  from the University of Hohenheim, Dr. Hamado Tapsoba (based in Ouga), and me. The workshop was conducted in French, which presented certain difficulties for me at times, but fortunately Bettina and David were able to translate for me as necessary.

Group shot of workshop participants, taken at the end of the week

Hamado was the overall workshop facilitator, and was assisted throughout by Bettina.

Hamado facilitating

Ric provided 'live' research study design. Below is a picture of him working with Moussa and Zoumana; they are sitting in front of the rest of the attendees discussing their research on Fonio, and he is helping them fine tune their methodology.

Ric, Moussa, and Zoumana

David provided assistance with statistical analysis, and he actually kicked off the entire workshop with a demonstration of ODK to illustrate how it can serve as a useful research tool for gathering data in the field.

Throughout the week, I worked in a consultative capacity with the project teams and helped them map their data and in a few cases do some preliminary spatial analysis. I managed to work with 11 out of the 12 teams. We used open source tools for everything, relying primarily on QGIS to generate data and maps for the projects.

Working with Laouali, an entomologist from Niger working on the GIMEM project, which aims to reduce the damage done by the pearl millet head miner

Here I am working with the Processing team, Fatou Bah and Moustapha Moussa. She is based in Burkina Faso and he is based in Niger.

Here are a few examples of maps I made with the research teams:

Bambara nut average yield in Kg/Ha

Fonio extent of cultivation with study sites, landcover, and isohyets

GIMEM sites in Mali, Burkina Faso, and Niger with study sites and landcover

Areas of climatic similarity for Seed Systems sites in Mali relative to the balance of the CCRP West African Region. The redder the cell, the higher the climatic similarity; the greener, the lower. I created this map using Homologue

I spent the vast majority of my time in Ouaga inside the hotel. However, I did have some time to explore the hotel grounds and the area immediately around the hotel. It was extremely hot the entire time I was there (mid-100s F during the day). There were a lot of lizards around (and occasionally in) the hotel where the workshop was held.
Rainbow agama, one of many species of lizards around (and occasionally in) the hotel
I'd read about millet beer prior to making the trip, and at our group dinner, David very helpfully asked the locals where I might be able to try some. Hamado expressed some reservations about doing so at a local village, explaining that he got terribly sick after drinking millet beer at one of the attendee's villages! A couple of days later, he gave me this:

RAAM, a (safe!) locally brewed millet beer, given to me by Hamado
The closest thing I can compare it to is a Belgian sour beer. It had a lot of interesting flavor notes, but on balance, I couldn't get past the sourness. Not my favorite beverage of all time, but at least I got to try it!

Parc Urbain Bangr Weogo, an excellent urban birding location
My flight did not leave Ouagadougou until 11 pm the day after the workshop ended, so I hired a cab to take me out to Parc Urbain Bangr Weogo at sunrise, a very large park northeast of the hotel. It has a variety of habitats, including scrub, riparian forest, and ponds. My main objective was to do some birding, and I was shocked at the diversity of species--I saw over 50 species in two hours! Truly remarkable. Highlights were the northern red-billed hornbill, African paradise flycatcher, Hoopoe, pied kingfisher, and little green bee eater.

I also saw a crocodile in one of the ponds.

When it started to get warm, I asked the taxi driver take me to the Village Artisanal de Ouaga, a government run market where local artisans sell their wares. It was refreshingly hassle-free and a great place to check out a wide variety of locally produced goods, including masks, jewelry, drums, tapestries, and bronze. Unfortunately there were very few tourists there, and all of the artisans were working hard and producing some pretty high quality work. I wanted to buy something from every one of them, but in the end purchased masks, jewelry, and bracelets from five different vendors.

Some of the wares on offer at the Village Artisanal de Ouaga

Overall, the visit was intense, occasionally challenging, and very productive. I truly enjoyed working with all of the researchers and the support staff, and hope to return to the region again someday to continue working with the CCRP projects. And maybe do a little more birding and exploring!