Table 4--WRIR 97-4097

Preliminary Conceptual Models of the Occurrence, Fate, and Transport of Chlorinated Solvents in Karst Regions of Tennessee

Table 4. Distributions of selected geomorphic variables among karst regions of Tennessee

[p10, 10th percentile; p50, median; p90, 90th percentile; p100, maximum; %, percent; <, less than; >, greater than]

	Depth to bedrock, in meters ¹	Land-surface slope, in degrees²	Streamflow recession index, in days per log cycle³	Percent of region in various sinkhole-density classes⁴	Reported cave entrances per 1,000 square kilometers⁵
Region	p10	p50	p90	Number of wells	p10	p50	p90	p100	p10	p50	p90	<1% sinkholes	1-10% sinkholes	>10% sinkholes
Inner Central Basin	0.9	2.4	7.3	2,544	0	0	2	14	32	32	32	50.2	46.1	3.7	10
Outer Central Basin	1.5	3.7	13.7	3,920	0	2	7	26	35	35	50	94.1	5.9	0	18
Eastern Highland Rim	3.7	14.6	25.0	3,347	0	0	5	22	50	65	140	70.2	23.3	6.5	20
Pennyroyal Plateau	4.9	11.0	18.3	529	0	0	1	9	50	80	80	31.8	52.0	16.2	10
Western Highland Rim	3.0	15.2	35.1	4,703	0	1	4	13	50	120	140	97.4	2.5	0.1	6
Coves and escarpments of the Cumberland Plateau	.9	8.2	25.9	745	1	8	14	34	32	50	100	87.8	7.8	4.4	63
Valley and Ridge	3.4	12.8	38.4	8,925	0	2	8	36	50	80	120	62.1	34.9	3.0	9
Western toe of the Blue Ridge	5.2	19.2	42.7	357	0	3	11	28	75	109	120	73.9	25.1	1.0	30

Depth to bedrock, in meters ¹

Land-surface slope, in degrees²

Streamflow recession index, in days per log cycle³

Percent of region in various sinkhole-density classes⁴

Reported cave entrances per 1,000 square kilometers⁵

Region

p10

p50

p90

Number of wells

p10

p50

p90

p100

p10

p50

p90

<1% sinkholes

1-10% sinkholes

>10% sinkholes

Inner Central Basin

0.9

2.4

7.3

2,544

50.2

46.1

3.7

Outer Central Basin

1.5

3.7

13.7

3,920

94.1

5.9

Eastern Highland Rim

3.7

14.6

25.0

3,347

140

70.2

23.3

6.5

Pennyroyal Plateau

4.9

11.0

18.3

529

31.8

52.0

16.2

Western Highland Rim

3.0

15.2

35.1

4,703

120

140

97.4

2.5

0.1

Coves and escarpments of the Cumberland Plateau

8.2

25.9

745

100

87.8

7.8

4.4

Valley and Ridge

3.4

12.8

38.4

8,925

120

62.1

34.9

3.0

Western toe of the Blue Ridge

5.2

19.2

42.7

357

109

120

73.9

25.1

1.0

^1. Data from private-well logs maintained by Tennessee Department of Environment and Conservation, Division of Water Supply.

^2. U.S. Geological Survey digital elevation model, scale 1:250,000.

^3. Distribution based on streamflow recession areas delineated by Bingham (1986) subdivided into 500 x 500 meter cells distributed among karst regions.

^4. Crawford and Veni, 1986; based on U.S. Geological Survey topographic quadrangle maps, scale 1:24,000.

^5. Cave-entrance locations from Barr (1961) and Matthews (1971).

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