The Flatness of U.S. States [pdf] | Hacker News Reader

The Flatness of U.S. States [pdf]

disruptivegeo.com

15 pointsmindcrime17 comments

Don't really like this measure of flatness. Measuring how flat a 90-m cell(square meters or 90m on a side not given in the abstract) is from the SRTM data set and then averaging this value over all the state's cells. Nevada, a state full of mountains(see US topo map[1]), is ranked #9 due to (I would guess) the presence of many flat dry lake beds (lakes with water are removed from the study for some reason not well stated). No wonder our intuition is wrong if the measurement used to calculate the value bad.

[1] https://upload.wikimedia.org/wikipedia/commons/5/50/Uspainte...

Yeah, this "taking the average" of relatively small areas seems to me a poor measure of "flatness". I mean, Colorado comes right in the middle at #25. Yes, the eastern portion of CO is very flat, but there are other objective potential measures that could potentially put CO much higher on the "hilly" scale.

Cool paper. Having lived all over the US I’d say the paper matches my mind-map of which states “feel” flattest, and yeah I definitely have noticed how flat Florida is and don’t perceive Kansas to be the flattest place - but I’ve spent a lot of time in the eastern half of the state where it’s moderately hilly.

It’s fascinating that the paper is pointing out the negative stereotypes around flatness and implying these harm states that are perceived to be flat. I’d be interested to see that unpacked a bit more.

"Do Florida’s dense forests mask its flatness?"

That's what I believe.

I've lived in FL (#1) and IL (#2). When I moved to central IL, I noticed it wasn't flat as S. FL. On a bike ride it was clear there were up and down slopes that I didn't have growing up.

But in Florida, either city or forest or scrub blocks out the view of the horizon, while in IL there were open plains where sometimes I could see the horizon under distant trees. It made IL feel flatter, even though I knew it wasn't.

I lived in Florida, and recall hearing that much of the state is actually below sea level. I saw some forests, but much of the state is swamp, or former swamps that were drained for suburbia.

I'll channel the spirit of Marjory Stoneman Douglas for a moment to point out that "swamp" is not a swamp but a slow-moving river. Quoting from https://en.wikipedia.org/wiki/Marjory_Stoneman_Douglas :

> Her most influential work was the book The Everglades: River of Grass (1947), which redefined the popular conception of the Everglades as a treasured river instead of a worthless swamp.

The view that it is worthless swamp, best turned into real estate, sugar cane, or other agriculture has greatly damaged the Everglades ecosystem. An ecosystem which replenishes the Biscayne Aquifer that the Miami metropolitan area drinks from, and which provides a bubble of fresh water to help prevent saltwater intrusion.

Going back to the main point, none of the natural land surface of Florida is below sea level, other than the trivial case of land exposed during low tide ("sea level" means "mean sea level").

If there were land below sea level, it would be covered by water. Most of the rock in Florida is porous limestone, which isn't an effective barrier to water. Parts of Miami flood during king tides, simply because of water rising up through the ground.

Or, go to https://en.wikipedia.org/wiki/Florida and see "Lowest point: Atlantic Ocean, Sea level".

Elevation span is probably a much more common way to think of this.

https://en.wikipedia.org/wiki/List_of_U.S._states_and_territ... (sort by elevation span)

I’ve never verified it, maybe because I’m scared it won’t be true.

But one of the few facts I remember to this day from 8th grade history, ages ago, is that no land is more than 20 feet above sea level in all of Florida.

Native Floridan here. Close but untrue. Highest point is 345 feet ASL[1].

[1] https://en.wikipedia.org/wiki/Sugarloaf_Mountain_(Florida)

105 meters is close enough to 345 feet to call them the same, and I think you mean Britton Hill not Sugarloaf.

The second paragraph of the article starts "What is the flattest state? Florida is the obvious answer, since its highest point is only 105m. above sea level, ..."

I grew up in Miami, at about 22ft elevation. The highest point in Miami-Dade is about twice that height above sea level.

Spoiler alert: Kansas is not the flattest state in the U.S. Actually, quite a few of these results at at least slightly surprising.

1 Florida

2 Illinois

3 North Dakota

4 Louisiana

5 Minnesota

6 Delaware

7 Kansas

8 Texas

9 Nevada

10 Indiana

11 South Dakota

12 Michigan

13 New Mexico

14 Arizona

15 South Carolina

16 Oklahoma

17 New Jersey

18 Iowa

19 Nebraska

20 Ohio

21 Arkansas

22 Mississippi

23 Utah

24 California

25 Colorado

26 North Carolina

27 Rhode Island

28 Maryland

29 Wisconsin

30 Georgia

31 Missouri

32 Idaho

33 Wyoming

34 Montana

35 Oregon

36 Maine

37 Alabama

38 District of Columbia

39 New York

40 Massachusetts

41 Washington

42 Virginia

43 Tennessee

44 Connecticut

45 Vermont

46 New Hampshire

47 Kentucky

48 Pennsylvania

49 West Virginia

I guess we'll never know how flat Alaska or Hawaii are, though I'd guess not very flat at all. I'm most surprised how many states are considered flatter by this paper than Colorado!

Yeah, the methodology they used generated a few somewhat surprising results. I suspect there are other reasonable ways of defining "flatness" that would yield markedly a markedly different ranking for some states.

"Eastern Colorado is just as flat as Kansas, both being in the High Plains Physiographic Section" (quoting the paper)

That's about 1/3 the state, so it brings down the average.

Michigan would probably be much lower but all the dips are full of water and turn into swamps and lakes which are excluded.

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