Ich erfinde ein falsches Maß für die Ebenheit namens "Ebenheitsindex" (FI) und kartieren Sie es hier. Ich habe FI als den quadrierten Höhenunterschied zwischen der minimalen und maximalen Höhe jedes Kreises (oder Kreisäquivalents) geteilt durch die Gesamtfläche mal 100.000 definiert.
AK und HI sind nicht enthalten, einfach weil sie nicht in meinem 100-m-DEM für die USA enthalten waren.
Von MrShiv
36 Kommentare
Surprised the Ozarks dont show up here, not as tall as they once were millions of years ago I guess.
This discounts large counties that are very mountainous. For example most counties in northern Nevada I would not call “flat”, they have large flat plains but also tall rugged mountains.
It’s not a bogus metric, but a lot gets hidden in that 0-36 range – would be interesting to see this with a scale that breaks up that range more.
I see Mounts Rainier and Hood popping out in Washington and Oregon, respectively
Ah yes, the famously flat counties of the Basin and Range. At the core, OP has a good idea, but it is hurt by having county size as a metric. Maybe go with elevation change by section (36 sq mi) or even by square mile.
This is so wrong
Cool. Interesting work. I think if you tinkered with the formula a little more in order to get more differentiation in the “flat” zone, it would be more informative. For example, there are several ski mountains in my county, and we would consider it “mountainous” but it’s listed as being as flat as Iowa or Florida. I’m not trying to argue that the math is wrong or anything, just saying that it’s too hilly to be good farmland, for example.
My county (actually parish as I live in Louisiana) is the definition of flat. The elevation ranges from sea level to 6 meters. The total area is 3,820,000 meters, so by my calculations, our flatness index is less than 1.
all of those counties that border the snake river and the blue mountains ayy
Coconino County in Arizona contains the San Francisco peaks (12.6k) and the bottom of the Grand Canyon (around 2k). Your map looks very flat!
Another way to approach this would be to calculate slope for your DEM, perhaps square it, then average it for each county. That would elevate places that are constantly undulating but perhaps not to a great height from those that are pancake flat.
This is so laughably bad.
Gilpin County Colorado looks interesting!
I think you’d be better off calculating the median difference in elevation between adjoining DEM cells. It would take more time to compute but would also give a much more representative picture of topographic variation. For example, much of the Cumberland and Allegheny plateau regions are deeply incised. The overall elevation variability in a county may be less than 1000m, but there are many, many valleys dissecting the uplands, making these regions anything but flat.
Maybe analyze for slope on your DEM and average the cells
I grew up in central Iowa and now live in western PA, and categorizing the „flatness“ of those two areas the same is an interesting way to parse the data.
Nice try, but needs work.
I looked at the formula and thought ??? but then read your first sentence calling it a „bogus measure“ lol.
But I want to entertain this. I understand why you divide it by the total area (it speaks to how drastic the elevation difference is) and I also kinda get multiplying it by some 10 value (to make what would be a really small number a whole number), but why square the difference? Why not just divide it by total area and pick your 10s value multiplier based on the range of numbers you get?
Is squaring it supposed to negate any negative numbers you get if you happen to have a minimum elevation drastically below 0? Or is it because total area is measured in square km/miles?
Windsor County letting Vermont down
I’m assuming since a lot of the flat counties are in fact not really flat, the scale is very much tilted towards an alpine persuasion. And even there, there are counties, like in Nevada for example that are flatter than you can believe… between pretty common and continuous mountain ranges. These are not shaded either.
Ummm Kern County in California only has two mountain ranges that go through it, and it’s considered flat?
Hm. I feel like this is more of a Prominent Mountains Index. It doesn’t usefully distinguish very flat counties from gently rolling counties, which seems to be the question of interest.
The Grand Canyon is flat😭
Literally the highest and lowest points in the continental US are in the same county (Inyo county California). That county is listed as being in the second flattest of your 5 levels of flatness. I’d go back to the drawing board for formula and visualization.
All that kept people from moving west from the 13 colonies were a few easily circumvented areas? Were the colonists stupid?
This is a fascinating map that makes Pittsburgh appear as flat as Indianapolis
Can anyone explain to me what this is even trying to say? Im lost as to what it even means in most cases.
I grew up in a county where I know the elevation changes by 400+ feet, but its listed as white.
Calling this a flatness index feels backwards to me, since higher values indicate the county is *less* flat.
“Index”
Counties in Arizona are enormous, larger than some states. Thus, the county of Grand Canyon is flat.
“The Grand Canyon is located in Coconino County, which is the second-largest county in Arizona. Coconino County covers over 18,600 square miles and is home to a number of other natural wonders, including the San Francisco Peaks, the Painted Desert, and the Meteor Crater.”
I mean one of the steepest roads in the country is in one of the „flat“ MA counties
The formula is quite ridiculous— but then I see that the creator called it a Bogus Measure.
Inyo County, CA has multiple mountain ranges that rise 10,000 feet from the adjoining valleys. Because the county is large (but mostly mountainous) it gets the second flattest category. Lowest point is 282 feet below sea level, highest is 14,505 above sea level. (that would be the lowest point in the Western Hemisphere, and the highest point in the contiguous United States.)
Pierce county in Washington goes from sea level (0ft) to the summit of mt rainier (14,411ft), and is 1805 sq miles.
So ((14411-0)^2/1805)*100000 =1.151×10¹⁰.
Which does not seem to be accurately represented here
Ok. Third comment. Clearly rage bait for us map nerds. San Bernardino County California has 11,500 feet of vertical relief but shows up as flat as Florida.
I love how Pierce County, WA is only different than the surrounding counties bc of Rainier 😂
Fresno County lowering the Sierras and raising the Central Valley stats.