SLIDE 1
Erik Severson, Research Associate and Interpretive Soil Scientist, CSES department, Virginia Tech
Erik Severson, Research Associate and Interpretive Soil Scientist, - - PowerPoint PPT Presentation
Erik Severson, Research Associate and Interpretive Soil Scientist, - - PowerPoint PPT Presentation
Erik Severson, Research Associate and Interpretive Soil Scientist, CSES department, Virginia Tech Well Aerobic soil Groundwater Trench Bottom Trench Bottom Trench Bottom Trench Bottom Clayton Site Clayton Site Left Side Lateral 3 Left
SLIDE 2
SLIDE 3
Groundwater
Well Aerobic soil
SLIDE 4
Clayey Horizon Trench Bottom Coarse-Textured
Clayton Site
Left Side – Lateral 3 8/23/1999
Clayey Horizon Trench Bottom Coarse-Textured Clayey Horizon Trench Bottom Coarse-Textured Clayey Horizon Trench Bottom Coarse-Textured
Clayton Site
Left Side – Lateral 3 8/23/1999
Source: Aziz Amoozegar, Lake Wheeler
SLIDE 5
SLIDE 6
Introduction
SLIDE 7
F
SLIDE 8
SLIDE 9
SLIDE 10
Flat Topography + Impermeable Layers = Perched Water Tables
SLIDE 11
SLIDE 12
- 1. Document morphology and monitor
saturation in the Appomattox and Bentley Soil Series.
- 2. Calculate % wet season RMFs were
saturated.
- 3. Confirm or deny epiaquic conditions.
SLIDE 13
- 4. Compare saturation differences of
entirely residual soils versus transported soils.
SLIDE 14
SLIDE 15
Location 1: Bentley Soils Location 2: Residual Soil
SLIDE 16
Appomattox Bentley
SLIDE 17
Cap and vent hole Annulus Bentonite gravel Restrictive Layer Slotted pipe Solid pipe
SLIDE 18
SLIDE 19
10 20 30 40 50 60 70 80 90 100 1/1 1/8 1/15 1/22 1/29 2/5 2/12 2/19 2/26 3/5 3/12 3/19 3/26 4/2 4/9 4/16 4/23 4/30 Date Depth (cm)
Average 30-day 20-day
SLIDE 20
10 20 30 40 50 60 70 80 90 100 1/1 1/8 1/15 1/22 1/29 2/5 2/12 2/19 2/26 3/5 3/12 3/19 3/26 4/2 4/9 4/16 4/23 4/30 Date Depth (cm)
Iron Concentrations: Chroma 3 depleted ped faces 5% 65%
SLIDE 21
1) Document Soil Morphology
And
2) Monitor saturation for the Appomattox and Bentley Soils
SLIDE 22
Ap Bt1 Bt2 2BCt 3CBt 3Ct
SLIDE 23
SLIDE 24
SLIDE 25
SLIDE 26
SLIDE 27
20 40 60 80 100 120 140 160 180 200
- 120
- 100
- 80
- 60
- 40
- 20
Oct-11 Mar-12 Aug-12 Jan-13 Jun-13 Nov-13 Apr-14
Precipitation (mm) Depth (cm)
5YR 5/8 (c) 10YR 7/8 (d) 10YR 7/4 (d) N/8 (d) Precipitation
SLIDE 28
SLIDE 29
Depleted ped faces n =36
41%
Concentrations n=11
23%
≥3 chroma depletions n=20
41%
≤2 chroma depletions n=12
65%
SLIDE 30
- 350
- 300
- 250
- 200
- 150
- 100
- 50
Sep-11 Apr-12 Oct-12 May-13 Nov-13 Jun-14
Depth (cm)
1.5M 3M Discontinuity
Perching confirmed at 6 out of 8 sites
SLIDE 31
Compare hydrology of entirely
residual soils vs. transported soils at same depths (1 m).
SLIDE 32
- 120
- 100
- 80
- 60
- 40
- 20
Nov-12 Mar-13 Jul-13 Nov-13 Mar-14 Depth (cm)
Residual Transported
SLIDE 33
Soils
- Avg. Water Table
30-day 20-day
Transported 81 64 91 Residual 95 83
SLIDE 34
Conclusions Transported soils perch water for extended periods on impermeable layers.
SLIDE 35
Conclusions Redox Features with chroma ≥3 indicate a fluctuating water table.
SLIDE 36
Conclusions Residual soils underneath transported soils were not saturated.
SLIDE 37
Conclusions Entirely residual soils were “drier” than transported soils.
SLIDE 38
Avoid use of transported soils with
restriction and perched water table
Avoid 1 M below lithologic discontinuity