Good idea. In fact, please let us rank all the cities in a country from highest to lowest on various metrics. I always learn a lot about a measure from comparing the highest to the lowest ranking items.
This just might be the most amazing thing I have found not only for density visualization but also for real estate investing considerations based on population. Have you considered about adding more cities from India?
I find the presentation of data a little confusing. When the graph shows a value for, say, 0 km – what does that mean? When hovered, a prompt says "X people live within 0 km of [city]". Isn't it rather a number of kilometres + 1? So for 0 km you show data for the ring 0-1km, for 1 km the ring 1-2km etc.?
Also I think I found an error in the data: for Vienna and The Hague it shows 30k ppl for 0 km, yet the densities for the first ring are higher than, say, Warsaw with 60k ppl for 0 km.
Tip for the future: it would be nice to show the centerpoints of cities used for calculations
Another useful metric would be what percentage of land within X kilometers of the city hall is unpopulated due to water (plus mountains, Indian reservations, military bases, and the like). For example, Dallas has been able to expand almost 360 degrees because it is surrounded by flat land. In contrast, San Francisco is surrounded by salt water and sizable mountains.
This has a big impact on housing costs because the percentage of the earth's surface that can be readily developed within, say, 50 kilometers of San Francisco's city hall is much lower than the percentage of the earth's surface within 50 km of Dallas's city hall, so the supply is more limited.
In turn, this appears to have a sizable impact on voting patterns: a house with a yard in a decent public school district is much more affordable within commuting distance of Dallas than of San Francisco, so people more focused on family formation flock to the Dallas region, while San Francisco attracts those less interested in having children. Not surprisingly, the "family values" party does better in the Dallas metro area than in the San Francisco metro area.
Visually, it's confusing that the Y-Axis and the bolded title text of the hover-over on the graphed lines are different measurements. https://imgur.com/a/oYUCCLQ
I just did a quick check with the 1km and 100m 2020 GSHL population grids with some areas of Madrid I know quite well, comparing it with official census population data from small statistical areas (census areas) and found significant underestimation of population density...
Census areas in Madrid are 2-3 hectares in size, and I'm seeing areas with consistent 300-600 people/Ha in the official census data, while the GSHL is just showing 200-300 at similar area sizes (or even smaller!).
The pipeline for an update is hopefully happening, because most of the data is quite old now. If you have a national statistical agency 1km map I can use instead that would be fantastic.
One quibble. I'm wondering if you have the right data for Washington DC? It seems understated. You say 1,660,000 million people live within 50 kilometers of DC, but the DC Metro Area is 6.4 million people according to Wikipedia (and DC/Baltimore metro is 9.5 million).
Here from Twitter. Could you tell me a bit more about the data on Israel and Palestine? And how you decided to classify Jerusalem as being in Palestine? Besides the political aspect, it's not clear to me how Palestinian data (if it is Palestinian data) could correctly estimate the population in all of Jerusalem since they can only access the Arab population and not the Jewish population. Israeli data covers both.
Give us top 10 lists by the different metrics
Good idea. In fact, please let us rank all the cities in a country from highest to lowest on various metrics. I always learn a lot about a measure from comparing the highest to the lowest ranking items.
This just might be the most amazing thing I have found not only for density visualization but also for real estate investing considerations based on population. Have you considered about adding more cities from India?
I find the presentation of data a little confusing. When the graph shows a value for, say, 0 km – what does that mean? When hovered, a prompt says "X people live within 0 km of [city]". Isn't it rather a number of kilometres + 1? So for 0 km you show data for the ring 0-1km, for 1 km the ring 1-2km etc.?
Also I think I found an error in the data: for Vienna and The Hague it shows 30k ppl for 0 km, yet the densities for the first ring are higher than, say, Warsaw with 60k ppl for 0 km.
Tip for the future: it would be nice to show the centerpoints of cities used for calculations
Another useful metric would be what percentage of land within X kilometers of the city hall is unpopulated due to water (plus mountains, Indian reservations, military bases, and the like). For example, Dallas has been able to expand almost 360 degrees because it is surrounded by flat land. In contrast, San Francisco is surrounded by salt water and sizable mountains.
This has a big impact on housing costs because the percentage of the earth's surface that can be readily developed within, say, 50 kilometers of San Francisco's city hall is much lower than the percentage of the earth's surface within 50 km of Dallas's city hall, so the supply is more limited.
In turn, this appears to have a sizable impact on voting patterns: a house with a yard in a decent public school district is much more affordable within commuting distance of Dallas than of San Francisco, so people more focused on family formation flock to the Dallas region, while San Francisco attracts those less interested in having children. Not surprisingly, the "family values" party does better in the Dallas metro area than in the San Francisco metro area.
Visually, it's confusing that the Y-Axis and the bolded title text of the hover-over on the graphed lines are different measurements. https://imgur.com/a/oYUCCLQ
Do we know how accurate the GSHL is in general?
I just did a quick check with the 1km and 100m 2020 GSHL population grids with some areas of Madrid I know quite well, comparing it with official census population data from small statistical areas (census areas) and found significant underestimation of population density...
Census areas in Madrid are 2-3 hectares in size, and I'm seeing areas with consistent 300-600 people/Ha in the official census data, while the GSHL is just showing 200-300 at similar area sizes (or even smaller!).
I plotted Madrid a couple of years ago here: https://danielalmazan.com/population/madrid_pop.html
The pipeline for an update is hopefully happening, because most of the data is quite old now. If you have a national statistical agency 1km map I can use instead that would be fantastic.
this is so sick and easy to use, well done
This is such an interesting work. I played with it a little bit and you can extract so many insights.
Thanks, great stuff.
One quibble. I'm wondering if you have the right data for Washington DC? It seems understated. You say 1,660,000 million people live within 50 kilometers of DC, but the DC Metro Area is 6.4 million people according to Wikipedia (and DC/Baltimore metro is 9.5 million).
Tom Forth's data for Washington DC is wrong (too low), but I don't know how to contact him.
Thanks for the tip! It had locked it on to Washington State. I've fixed a few cities tonight (including DC) with more being updated soon.
Here from Twitter. Could you tell me a bit more about the data on Israel and Palestine? And how you decided to classify Jerusalem as being in Palestine? Besides the political aspect, it's not clear to me how Palestinian data (if it is Palestinian data) could correctly estimate the population in all of Jerusalem since they can only access the Arab population and not the Jewish population. Israeli data covers both.
Love this, could you add Washington D.C?
Thanks for the tip - I've added DC.