2018 SWCS International Annual Conference July 29-August 1, 2018 Albuquerque Convention Center

1. Albuquerque, NM
Characterization and Evaluation of Riparian Buffers
on Sediment Load in Goodwin Creek Watershed
1
Henrique Momm
Joel Miranda
Department of Geosciences
Middle Tennessee State University
Ronald Bingner
Lindsey Yasarer
Robert Wells
Roger Kuhnle
USDA-ARS
National Sedimentation Laboratory

2. Albuquerque, NM
Riparian Vegetation

3. Albuquerque, NM
The primary function of riparian
buffers is to reduce overland flow
velocity, promote infiltration, and
sediment/chemical deposition
Characterization of Riparian Vegetation
Ponding of water upstream of
buffer, spreading of flow passing
through, and increased surface
roughness
A quantitative measure of the
sediment transport reduction by
riparian buffers
AGNPS-GIS Buffer Utility Feature (AGBUF)
Flow Buffer width
Local slope
One-dimensional representation (field scale)
Profile TE
Profile TE

4. Albuquerque, NM
Profile TE is aggregated to calculate
maximum TE (MTE) and catchment
area to riparian zone
Characterization of Riparian Vegetation (continued)
AnnAGNPS
Soil characteristics, sediment sizes, cell peak
flow, and peak flow to buffer
B
C
MTE = 90%
MTE = 47%
MTE = 97%
Actual TE
Sand
Actual TE
Small
Aggregates
Actual TE
Silt
MTE
“short-circuits” or concentrated flow path CFPs

5. Albuquerque, NM
Objective 1: Characterization and quantification of sediment trapping efficiency of natural
riparian vegetation at watershed scale
Goodwin Creek Watershed
Objective 2: The effect of concentrated flow paths to sediment yield and loads
Objective 3: Sediment loads of different particle sizes are contrasted by different
alternative scenarios with varying buffer width and concentrated flow paths assumptions
Topography: 1m DEM
2,271 cells (0.94ha)
911 reaches (170m)
Simulation: 1982-1991
Flow: 4 stream gauges
Sediment: 1 gauge
Two steps
calibration/validation

6. Albuquerque, NM
Channel Network
GCW Boundary
Buffer zone digitized
Goodwin Creek Watershed (continued)
10
100
1000
10000
100000
0 50 100 150 200 250 300 350 400 450 500 550 600
0
10
20
30
40
50
60
70
80
90
100
(a)
Frequency
Cumulativepercentage
Upstream contributing area, m
2
0
500
1000
1500
2000
2500
3000
0 10 20 30 40 50 60 70 80 90 100
0
10
20
30
40
50
60
70
80
90
100
(b)
Frequency
Cumulativepercentage
Flow path length, m
10
100
1000
10000
100000
0 50 100 150 200 250 300 350 400 450 500 550 600
0
10
20
30
40
50
60
70
80
90
100
(a)
Frequency
Cumulativepercentage
Upstream contributing area, m
2
3000
90
100
(b)

7. Albuquerque, NM
Goodwin Creek Watershed (continued)
Set ID
Riparian zone
layer
Buffer
width,
m and ft
CPFs
threshold,
ha
A Actual digitized 1985 variable none
B
0 digitized 1985 variable 0.0010
1 digitized 1985 variable 0.0025
2 digitized 1985 variable 0.0050
3 digitized 1985 variable 0.0100
4 digitized 1985 variable 0.0500
5 digitized 1985 variable 0.1000
6 digitized 1985 variable 0.5000
7 digitized 1985 variable 1.0000
C
8 GIS buffer analysis 2.29 7.5 none
9 GIS buffer analysis 4.57 15 none
10 GIS buffer analysis 9.14 30 none
11 GIS buffer analysis 15.24 50 none
12 GIS buffer analysis 30.48 100 none
D
13 GIS buffer analysis 30.48 100 0.0010
14 GIS buffer analysis 30.48 100 0.0025
15 GIS buffer analysis 30.48 100 0.0050
16 GIS buffer analysis 30.48 100 0.0100
17 GIS buffer analysis 30.48 100 0.0500
18 GIS buffer analysis 30.48 100 0.1000
19 GIS buffer analysis 30.48 100 0.5000
20 GIS buffer analysis 30.48 100 1.0000
Development of alternative scenarios
CFPs on actual conditions
Buffer width on managed
buffers
CFPs on managed buffers

8. Albuquerque, NM
Goodwin Creek Watershed (continued)
Development of alternative scenarios

9. Albuquerque, NM
RESULTS – Field Scale
0 25 5012.5
Meters
Reaches
Flow Accumulation
raster grid cells
High : 10773
Low : 0
CELL 7442 CELL 1912

10. Albuquerque, NM
RESULTS – Field Scale (continued)
0
20
40
60
80
100
120
140
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
AnnAGNPS Cell: 7442
SedimentTrapped-Silt[Mg]
2.29m(7.5ft)
4.57m(15ft)
9.14m(30ft)
15.24m(50ft)
30.48m(100t)
0
20
40
60
80
100
120
140
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
AnnAGNPS Cell: 1912
SedimentTrapped-Silt[Mg]
0
20
40
60
80
100
120
140
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
AnnAGNPS Cell: 7442
SedimentTrapped-Silt[Mg]
0.001 ha
0.005 ha
0.050 ha
0.500 ha
1.000 ha
0
20
40
60
80
100
120
140
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
AnnAGNPS Cell: 1912
SedimentTrapped-Silt[Mg]
57
74
95
131
Considering 30.48m (100ft):
• Cell 7442 ->
• 65% of cell area drains into buffer
• MTE: 99%
• Cell 1992 ->
• 77% of cell area drains into buffer
• MTE: 88%
Shape of catchment,
flow path patterns
topography

11. Albuquerque, NM
RESULTS – Field Scale (continued)
0
20
40
60
80
100
120
140
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
AnnAGNPS Cell: 7442
SedimentTrapped-Silt[Mg]
0.001 ha
0.005 ha
0.050 ha
0.500 ha
1.000 ha
0
20
40
60
80
100
120
140
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
AnnAGNPS Cell: 1912
SedimentTrapped-Silt[Mg]
Considering 30.48m (100ft) with DA
threshold of 0.05ha and 0.5ha:
• Cell 1992 ->
• Same results
• Cell 7442 ->
• Significant difference in sediment
trapping efficiency
One flow path that drains 62% of total cell area (0.7ha)
0 25 5012.5
Meters
Reaches
Flow Accumulation
raster grid cells
High : 10773
Low : 0

12. Albuquerque, NM
RESULTS – Watershed scale
Station 14 Comparing observed versus simulated
1985 buffer with varying assumptions of CFPs
Real condition between no buffer and buffer with no CFPS
• No buffer not realistic -> locations with several meters of forest
• No CFPs not realistic -> not managed
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0 1 2 3 4 5 6 7
Nash-Sutcliffe
Alternative Scenarios
Small
Sand
Total
Actual-Small
Actual-Sand
Actual-Total
0.00
5.00
10.00
15.00
20.00
25.00
30.00
0 1 2 3 4 5 6 7
PBIAS
Alternative Scenarios
Small
Sand
Total
Actual-Small
Actual-Sand
Actual-Total
Less CFPs Less CFPs

13. Albuquerque, NM
RESULTS – Watershed scale
OUTLET – Constructed buffers
Optimum width
Spatial configuration
Complex interaction
between CFPs and
buffer width
0.65
0.70
0.75
0.80
0.85
0.90
0.95
0 5 10 15 20 25 30 35
y=-0.5771 *x-0.3958
+ 1.079
Adjusted R2
: 0.9998
(a)
AverageTE,%
Riparian buffer width, m
Constructed
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
0 5 10 15 20 25 30 35
y=2.098 *x
-0.2934
- 0.5851
Adjusted R
2
: 0.9979
y=0.1288 *x-0.3037
+ 0.1776
Adjusted R2
: 0.9988
(b)
Sedimentyield,Mg/ha/yr
Riparian buffer width, m
Clay Silt
0.30
0.40
0.50
0.60
0.70
0.80
0.90
0.001 0.01 0.1 1
y=0.7798 *x0.1498
+ 0.0976
Adjusted R
2
: 0.9934
y=0.4179 *x0.1324
+ 0.2766
Adjusted R2
: 0.9977
(c)
AverageTE,%
Threshold drainage contributing area, ha
Constructed Natural
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
2.20
0.001 0.01 0.1 1
y=-1.864 *x
0.3359
+ 2.261
Adjusted R
2
: 0.9909
y=-0.1089 *x
0.3788
+ 0.3474
Adjusted R2
: 0.9958
(d)
Sedimentyield,Mg/ha/yr
Threshold drainage contributing area, ha
Clay Silt

14. Albuquerque, NM
Take Home
• Natural riparian vegetation contributes to sediment TE
• Sediment yield – CLAY 0.51 Mg/ha/yr (no buffer) vs. 0.32 Mg/ha/yr (buffer)
• Sediment yield – SILT 3.73 Mg/ha/yr (no buffer) vs. 1.43 Mg/ha/yr (buffer)
• Sediment yield – SAND 0.14 Mg/ha/yr (no buffer) vs. 0.04 Mg/ha/yr (buffer)
No Buffer Buffer no CFPs
Actual conditions
• Importance of buffer maintenance
• Significant impact of CFPs to reduce the TE of riparian vegetation
• Potential similar TE of well maintained narrower buffer than wider with CFPs
• Less land removed from production

15. Albuquerque, NM
Take Home (continued)
• There isn’t a “one size fits all” solution
• Shape of field catchment in relation to stream
• Flow path pattern (berms, topographic swales, furrows, etc.)
• Sediment size and/or chemical in study site
• Future Studies
• Evaluation of modeling technology with field-based measurements of
riparian vegetation in the field
• Methods for optimal location and configuration (where and how wide)
• Integration with other conservation practices (wetlands, grassed waterways,
cover crops, etc).

16. Albuquerque, NM
Thank you
Questions??

17. Albuquerque, NM
Goodwin Creek Watershed (continued)

18. Albuquerque, NM
RESULTS – Watershed scale
OUTLET – Constructed buffers
(A) (B)
(C) (D)
Cell load per unit of area
Mg/ha/yr
< 0.013
0.013 - 0.625
0.625 - 1.476
> 1.476001
0 2 41
Kilometers