USDA blindERS misranks California counties on the Natural Amenities Scale

Last week the Washington Post posted an awesome article and maps entitled "Every county in America, ranked by scenery and climate." It includes a very cool graphic that shows each county rank as a mouseover. It also contains separate maps for each amenity used to create the overall index: average January temperature, average January days of sun, low winter-summer temperature gap, low average July humidity, topography scale, and water area as a proportion of the County. Click on the map below to go to the article.

The data come from the USDA Economic Research Service's Natural Amenities Scale. The 1999 ranking (not expected to need much updating) is based on the factors mentioned above, with the following 26 California counties ranking in the "extremely high" category in the following order:

1. Ventura
2. Humboldt
3. Santa Barbara
4. Mendocino
5. Del Norte
6. San Francisco
7. Los Angeles
8. San Diego
9. Monterey
10. Orange
12. Santa Cruz
13. Contra Costa
14. Calaveras
15. Mariposa
16. Mono
17. San Mateo
18. Marin
20. Sonoma
21. San Luis Obispo
23. Napa
26. Alpine
28. Nevada
29. Amador
30. Stanislaus
34. Tuolumne
35. Inyo

Only 9 other counties outside of California--all in Nevada, Colorado, and Arizona--made it into the top category. The two in Nevada are adjacent to Lake Tahoe. The only two in the top 20 are in Colorado.

As for the rest of California's 58 counties, 22 are in the "very high" category, and 9 are ranked "high". Just one, Sutter County, is ranked "average".

It is the relative ranking of the top California counties that caught my attention first, and then the outliers--mainly the ones that got gipped. Then the individual maps revealed where some of the problems are. Downloading the data allows identification of how the problems happened. While any index is going to have problems due to averaging, clearly, the USDA ERS had blindERS on when it stopped where it did and called it good.

Again, this analysis and these maps are very cool--come on, a climate and topography ranking of California's counties? That is just awesome! So don't forget that when I focus on some refinements that could be made to improve it. And naturally, I will focus on California, since that is what my blog is about.

The first thing I wonder, and anyone wonders of course, is "what about places I have lived?" Well, I've lived almost my entire life in four California counties. According to the NAS, I'm generally heading down the list to less scenic and comfortable climates. This is probably true, for the most part. My July temperatures are getting cooler, although I've always lived in counties with average July temperatures in the 60s. I've lived in the county with the 4th-coldest January average temperature and the 3rd lowest July relative humidity (Mono), both of which aren't necessarily comfortable--but the extreme cold January temperature (for California) gets a near-even score when compared to the rest of the country, and the extremely dry July relative humidity is a big positive. I'm getting less January sunlight than I used to. But I now live in the county with the 3rd-highest percentage covered by water (Marin).

Central Coast Counties - gipped on July humidity
     So the ranking of the coastal California humidity is the first (and possibly biggest) problem with the index I will address. Every county from San Francisco to San Luis Obispo gets a 74% average July relative humidity. The first problem is how that is exactly the same value over 200 miles... clearly we have a problem with averaging of the input data. The second problem is that the highest humidities are between evening and morning, when temperatures are cooler and people aren't outside as much. During the day, when people are out and the temperature is warm, the fog burns off and humidity is lower. Any ranking of humidity that puts the central California coast equal with the southeast U.S. is missing something. What it is missing is VPD--vapor pressure deficit. Instead of using relative humidity, the index should use VPD, or the absolute difference between how much water is in the air and how much it can hold. VPD is what controls how much of your sweat evaporates--not relative humidity. And if it isn't even hot enough to sweat in the first place, then why is humidity a problem? The summertime morning and evening fog is nice, and I missed it when I lived in the higher-amenity-due-to-lower-humidity Mono County.

San Bernardino County - gipped on July humidity and topography
     Of the counties in the southern two-thirds of the state with which I'm most familiar, the main county that stands out as completely and wrongly-ranked is San Bernardino.The San Bernardino Mountains contain the highest peak in Southern California, at 11,502 feet, and yet its topography ranks a lot lower than all the other Southern California counties--which all get the highest ranking. This is just wrong--San Bernardino should also get the highest ranking. Unfortunately, if the highest ranking doesn't cover 25% of the county, it doesn't get it--even though most of San Bernardino's population is near the high topography. The problem is that San Bernardino County is the biggest county in the country, so its highest topography gets averaged out. To add insult to injury, the humidity chosen is 68%, equal to the other Southern California counties, when anyone familiar with the county knows it is not a coastal climate. Riverside County skirted the topography problem, but is another desert county suffering from the same humidity averaging as San Bernardino.

Sutter County - gipped on topography
      Sutter County is the only average county in the state. All the other children are above average. What did it do to deserve this lowest ranking? It suffers from low winter sun and little topographic variation. It is the only county in California with the lowest score for topography--a 1. The Sutter Buttes, while prominent, don't cover enough of the county to make the USDA ERS say it isn't flat. Sacramento County barely escapes this fate. And while it is near the majestic Sierra Nevada, it is the 6th-smallest county in the state, so unless it annexes the counties to the east (or unless the ERS changes its rules), it can't get a better topographic score.

Counties that lucked out
     The north coast seems a bit lucky to have escaped a greater downranking for its lack of winter sun and its cold winters. Anyone who thinks Humboldt and San Luis Obispo get almost the same amount of winter sun must have blindERS on. And counties don't get downranked for cold winters until they get really uncomfortably cold--like snow-on-the-ground cold. On the other hand, the north coast's and San Francisco's July temperatures are really too cold, yet the index doesn't seem to mind, giving them the highest rankings for July temperature. That is a major shortcoming of the NAS--not recognizing that people move away from those areas because July is too cold (and/or foggy) there.

So there you have it. I didn't address water area because the ERS seemed to actually put some thought into adjusting that index so it wasn't biased. Good job. Now fix the other problems. You'll have to do another update anyway with climate change making some areas more inhospitable and mountaintop removal mining flattening parts of the Appalachian topography. Although sea level rise will greatly increase the amenities of flooded communities (according to the index), if we can remove some more obsolete dams, the water areas of some counties should decline. Which is a good thing, since the amenities of a river are natural but those of a reservoir are not--but that is another thing the Natural Amenities Scale does not take into account.