Hyogo Prefecture, Japan Population Choropleth

This is practice of command line cartography following tutorial by @mbostock. For detail explanation, please look into Bostock’s tutorial.

I like data visualisation and D3. For long time I made many bar chart, line chart, scatter plot and histogram. But I never made map because data used in mapping GeoJSON, TopoJSON were intimidated me and I had no idea what should I visualise in map.

Then I read @mbostock’s blog Command-Line Cartography, Part 1. It was very nice and short tutorial and I tried to make map of Hyogo prefecture Japan where I live (people out side of Japan probably don’t know about Hyogo. It’s in west of Japan next to Osaka and Kyoto pref. It’s biggest city and I happen to live in is Kobe-city). It took only 20–30 min for part 1 and part 2. The most difficult part was to find shape file data to use.

Download Shape Data

First download shape file data for creating map. Data is available from Japanese government MILT (Kokudo Kotsu-sho)’s GIS data download service http://nlftp.mlit.go.jp/ksj/index.html.

Create Map

I downloaded Hyogo prefecture data zip. Unzipped file and there is shape file data (N03–16_28_160101.shp for my case). Use shp2json and create GeoJSON file.

shp2json N03-16_28_160101.shp -o hyogo.json

It’s easy to create svg map from GeoJSON file with geo2svg .

geoproject 'd3.geoMercator().fitSize([960, 960]), d)' < hyogo.json > hyogo-merc.json
geo2svg -w 960 -h 960 < hyogo-merc.json > hyogo-merc.svg

So what should I visualise with this map?

Map of hyogo prefecture, Japan

Shrinking Population

We had census year in 2015 and the result came recently. In Japan, the population is start to decline for the first time since the statistic started in 1920. In 2015 total population of Japan was 1,27 million 0.94 million less from 2010. In Hyogo prefecture it was 5.53 million in 2015 and it was 53,000 less from 2010. I’m interested in how population is changed in each city in Hyogo prefecture. So I created choropleth of population of Hyogo prefecture with GeoJSON data I created and census data.

I wanted to show how I processed census data and joined to GeoJSON but it is difficult because I used excel to process csv data. So I just show the choropleth map I made. If you interested in how to create choropleth using command line tools see @bostock’s blog.

Population Change of Hyogo Prefecture

This is the colopreth of population change rate of Hyogo from 2010 to 2015. There is no scale in this map so it’s hard to see what this means. Pink means negative change and green means positive change. Range is -10% to +10%.

Hyogo prefecture, Japan population change from 2010 to 2015

You can see most areas coloured pink so in those areas population is declined from 2010. You may also see left side (it’s west actually) is more negative and right side (east) is more positive or less negative. It’s same to north and south. It basically means south east is urbanised area and population is growing. The only area it coloured dark green is Kobe city’s most urbanised area. North and west side especially north west area is countryside and population is shrinking. Shrinking population is currently subtle but I feel this will impact Japanese society and economy substantially.