2020/05/08

Inspection of Tornado Damage using Satellite Imagery

March 3rd, 2020 a deadly tornado touched down in Putnam County, Tennessee. It's 8.2 mile path destroyed more than 100 homes and left a normally happy community heartbroken and distraught. A week on, this is an analysis of what happened using GIS data and aerial imagery.

Inspection of Tornado Damage through Satellite Imagery

How do we get to the above map? The track was provided by National Weather Service (NWS). The track buffer was made using attribute data provided by NWS.

NWS update for Putnam County Tornado
Regions affected: Putnam County, City of Baxter, City of Cookeville
Max Rating: EF-4
Max Winds: 175 mph
Path Length: 8.2 miles
Path Width: 500 yards
Time on the ground: 8 min
Forward speed: 65 mph
Buildings destroyed: 100
Road Crossings: 35


Affected Area (500 yard buffer of tornado path)
Buildings within affected area: 1,812
Landuse:
Land use / Land cover Acres Percent
Agriculture 1,220.34 38.78%
Commercial 194.65 6.18%
Industrial 56.76 1.80%
Public/Semi-Public Uses 113.28 3.60%
Residential 1,052.35 33.44%
Transportation 226.80 7.21%
Vacant 283.03 8.99%

Survey summary:
A violent tornado tracked across western and central Putnam County, resulting in numerous destroyed homes, 30-35 of which were destroyed completely, and caused 88 injuries and 18 fatalities. The tornado began 2.5 miles northwest of Baxter where it produced EF-0 damage for 2.7 miles as it crossed Gainesboro Highway. The tornado intensified to EF-1 and EF-2 intensity in the Prosperity Pointe subdivision just north of us 70N/Nashville Highway and further intensified to EF-3 as it crossed Bloomington Road and Clemmons Road, severely damaging several homes. The tornado then became violent for 0.8 miles as it entered the area around McBroom Chapel Road, where it reached EF-4 intensity, completely destroyed over a dozen homes, and caused numerous fatalities with the heaviest damage concentrated on Hensley Drive. EF-4 damage continued eastward to Echo Valley Drive, where an apartment complex was completely destroyed. EF-2 and EF-3 damage continued eastward for 2.0 miles, affecting homes along us 70N/W Broad Street, before rapidly coming to an end near n Franklin Avenue just west of Cookeville Regional Medical Center.

2020/05/07

Mean Elevations and Slopes of Tennessee Counties



Elevation units are feet, and slope units are degrees. Based on analysis using 10 meter DEMs.

Top Five Mean Elevation Counties: Johnson (2904.53'), Unicoi (2754.86'), Carter (2654.64'), Sevier (1970.47'), Cumberland (1793.50')
Top Five Mean Slope Counties: Unicoi (20.10°), Sevier (17.24°), Johnson (16.73°), Carter (16.38°), Hancock (16.01°), Cocke (15.26°)


County Slope_Mean Slope_STD Elev_Mean Elev_STD
Anderson 12.68 8.80 1292.74 563.60
Bedford 4.13 4.60 840.61 114.80
Benton 5.31 5.02 468.24 72.67
Bledsoe 7.52 6.71 1601.02 429.28
Blount 12.88 10.54 1411.09 718.40
Bradley 5.31 4.93 853.80 93.81
Campbell 14.96 8.69 1583.08 454.08
Cannon 9.83 8.54 1001.09 182.71
Carroll 3.52 3.06 462.33 58.26
Carter 16.38 9.81 2654.64 787.57
Cheatham 9.19 7.39 594.66 103.34
Chester 3.85 3.38 480.23 53.59
Claiborne 13.99 8.30 1482.68 309.92
Clay 12.43 9.99 803.74 137.30
Cocke 15.26 10.13 1738.72 745.83
Coffee 3.90 5.81 1088.69 119.77
Crockett 1.77 1.63 339.62 36.62
Cumberland 6.79 5.81 1793.50 205.51
Davidson 6.93 7.06 586.80 121.13
Decatur 5.40 4.73 142.72 20.44
DeKalb 10.51 9.46 870.45 162.40
Dickson 7.01 5.12 705.97 103.97
Dyer 1.43 2.46 292.36 43.73
Fayette 2.52 2.46 392.83 63.14
Fentress 9.16 7.81 1492.17 255.99
Franklin 6.43 6.89 1168.15 323.39
Gibson 2.13 2.06 366.59 51.53
Giles 7.67 5.98 822.75 122.02
Grainger 10.81 8.20 1282.26 250.31
Greene 9.83 8.69 1534.04 512.59
Grundy 6.91 6.96 1729.67 320.27
Hamblen 6.68 5.88 1246.31 132.15
Hamilton 6.91 6.84 964.84 371.16
Hancock 16.01 8.74 1538.72 261.40
Hardeman 3.76 3.70 457.72 73.56
Hardin 5.07 5.18 508.68 118.10
Hawkins 12.60 9.34 1414.97 253.99
Haywood 1.51 1.67 331.73 39.55
Henderson 4.06 3.39 490.68 55.08
Henry 3.55 3.30 467.27 66.87
Hickman 9.81 6.97 685.17 114.21
Houston 8.43 5.48 576.85 104.52
Humphreys 7.78 6.25 564.28 127.14
Jackson 14.50 9.62 780.70 156.60
Jefferson 6.58 6.31 1146.02 169.32
Johnson 16.73 9.31 2904.53 514.64
Knox 6.85 5.94 1004.30 121.93
Lake 0.49 1.20 279.92 12.74
Lauderdale 2.38 3.65 301.44 68.54
Lawrence 5.58 5.28 876.66 98.05
Lewis 9.04 6.41 848.03 90.27
Lincoln 6.06 5.66 841.89 111.79
Loudon 6.37 4.98 915.74 90.13
Macon 9.59 7.84 862.89 104.61
Madison 3.03 3.16 435.52 62.40
Marion 9.77 8.42 1307.63 489.69
Marshall 4.89 5.31 816.58 133.78
Maury 6.25 5.52 737.37 108.14
McMinn 6.59 5.83 912.80 148.42
McNairy 4.00 3.43 482.03 51.84
Meigs 5.85 5.59 807.15 93.24
Monroe 12.60 9.82 1438.11 734.46
Montgomery 4.93 4.42 534.74 80.46
Moore 8.54 6.25 974.91 113.31
Morgan 10.97 8.10 1492.93 342.80
Obion 3.04 4.25 349.25 54.10
Overton 9.45 7.40 1206.61 307.17
Perry 10.92 7.18 602.85 129.32
Pickett 11.09 8.52 1054.35 295.84
Polk 13.99 10.12 1372.48 507.54
Putnam 9.10 8.23 1189.20 351.15
Rhea 7.02 7.05 1149.67 447.65
Roane 8.61 7.13 910.28 161.04
Robertson 3.75 3.90 671.02 88.38
Rutherford 2.72 3.54 683.15 126.36
Scott 13.84 8.60 1536.96 314.72
Sequatchie 8.39 7.18 1654.80 477.38
Sevier 17.24 10.78 1970.47 1226.77
Shelby 2.23 2.74 287.00 50.06
Smith 9.97 7.36 677.02 144.73
Stewart 7.11 5.50 508.11 94.17
Sullivan 11.27 9.01 1700.57 426.13
Sumner 5.55 5.67 695.15 144.09
Tipton 2.44 3.11 311.85 58.80
Trousdale 6.86 5.96 616.25 125.99
Unicoi 20.10 9.86 2754.86 680.49
Union 11.15 7.99 1231.62 164.21
Van Buren 7.29 6.55 1578.60 333.18
Warren 5.08 5.50 1109.30 246.73
Washington 8.88 8.09 1714.72 276.72
Wayne 9.06 6.58 787.47 142.44
Weakley 2.52 2.50 394.16 47.82
White 7.05 6.59 1192.64 333.47
Williamson 6.65 5.74 782.71 99.28
Wilson 4.31 4.05 653.76 135.52