11th International Drainage Symposium August 30-September 2, 2022 Des Moines, Iowa

1. Effect of Vegetative Filter Strips on
Sediment Deposition in Drainage Ditches
in Littoral Zone of Lake Sainte-Pierre in
Quebec, Canada
The 11th International
Drainage Symposium
Zhiming Qi, Birkhoff Li, Monique Poullin, Shiv Prasher
Zhiming Qi, Associate Professor (Presenter)
Birkhoff Li, MSc. Graduate Student
Shiv Prasher, James McGill Professor
Department of Bioresource Engineering, McGill University
Monique Poulin, Associate Professor
Département de Phytologie, Université Laval

2. Outlines
• Introduction
• Objectives
• Methods:
Sites, vegetative buffer treatment, sediment
measurement (ditch volume), grass
• Preliminary Results

3. Lakes in Canada
Lac Sainte Pierre

4. Lac Sainte-Pierre
Littoral Zone
353 km2 (136 sq mi)
About ¼ of Story County, Iowa

6. Agricultural drainage ditches (after flooding)

7. Lac Sainte-Pierre
spring flood

8. Sediment deposition in
drainage ditches

9. Ecological Impacts
Photo Eric Labonté -
MAPAQ

10. Objectives
• To investigate the effectiveness of vegetative filter
strips on reducing sediment deposition in drainage
ditches in the coastal area of Lac Saint Pierre.

11. Site St Cuthbert
Site Yamachiche
Site Baie-du-Febvre
Methods
Three sites
Three ditches at
each site
500-1000 m long
4-6 m wide
Cleaning: Nov 2019
Grass sowed: May 2020
Ditch monitored: 2020-
now
Site Yamachiche

12. • Ditch Trenching (Late Fall 2019)

13. • Vegetative Buffer Strip (0, 2, & 4m wide; sowed in May 2020)

14. DTM data of the control ditch at site St
Cuthbert, Aug 10th, 2020
• LiDAR Scan
Scanned 4 times:
October, 2019 (before trenching)
November, 2019 (after trenching, snowed)
August 2020
October 2021
YellowScan LiDAR
Surveyor mounted below
a DJI Matice 600 Pro UAV
though a contract with
MVT Geo-solutions Inc. in
Quebec City.

17. • Total station survey
• 20m interval along
the ditch
• 25cm between two
points at each cross
section
• Conducted after the
spring flooding and
before the snow in
Nov.
8
0
m
5.75 m

18. Ditch survey at site Saint-Cuthbert
• Total station survey
• 20m interval along each ditch
• 2 round per year
• 1st round from June to July
• 2nd round from September
to October

19. Total Station Survey at Yamachiche in Nov 2019

20. Total Station Survey at the Lac Sainte Pierre sites

22. -2
-1
0
Height
(m)
-2
-1
0
0 1 2 3 4 5 6
Height
(m)
-2
-1
0
0 1 2 3 4 5 6
Height
(m)
Distance from the reference point at the start of the ditch
cross-section (m)
Step 1. A horizontal auxiliary
line is made based on the
highest point of the ditch
cross-section (m)
Step 2. The area of the closed
polygon created by auxiliary line and
the ditch profile is calculated using
the GIS library
𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒
= 𝑐𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 ∗ 20 𝑚
Cross sectional area
= 𝑡ℎ𝑒 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑐𝑙𝑜𝑠𝑒𝑑 𝑝𝑜𝑙𝑦𝑔𝑜𝑛
Ditch volume calculation (Total Station)

23. Robel height measurement
1.0 m
10
9
8
7
6
4
2
5
3
1
4 m
• To evaluate the vegetation
density close to the ditch
• Approximately 60m
interval along each VFS
• Conducted during fall in
2020 & 2021

24. Preliminary Results

25. Preliminary Results: 1) LiDAR Survey
Height decreased
between Dec 16, 2019
and August 10, 2020
Height increased
between Dec 16,
2019 and August
10, 2020
Distribution of sediment
accumulation and loss

26. DTM data comparison of the
control ditch at site St Cuthbert
between December 2019 and
August 2020
Sediment change calculation
Site
Baie du
Febvre
St Cuthbert Yamachiche
Buffer
strip
width
(m)
0 -1725 -1686 NA*
2 -701 -497 107
4 -663 -382 -353
Table 1 Sediment volume change (m3) over the
scanning area from winter 2019 to summer 2020
• Most ditches had sediment
accumulation during the
period between two LiDAR
scans (sediment volume
change < 0: decreasing)
Preliminary Results: 1) LiDAR Survey
*Note: the control ditch changed at site Yamachiche

27. * Control ditch changed to the one on the east side of the old
control in 2020 due to dense vegetation along the old control.
• Significant difference of ditch
volume between June and
November (Paired t test,
P=0.022)
Table 2. Ditch volume (m3) in 2019 and 2020
Site
Buffer
strip
width
(m)
Oct 2019
before
trenching
Nov 2019
right after
trenching
Jun
2020
Nov
2020
BDF
0 1414 1250 1165
2 856 1032 999
4 1354 1344 1375
STC
0 229 558 537
2 446 517 490
4 297 525 504
YMC
0* 729* 938* 628* 583*
2 486 522 590 532
4 837 987 549 536
* Control ditch changed to the one on the east side of the old
control in 2020 due to dense vegetation along the old control.
• Ditch volume after trenching in general decreased which
indicating a net sediment deposition
Preliminary Results: 2) Total Station Survey
2020

28. Total statoin survey
Percentage of ditch volume change from
June 2020 to November 2020
• Possible explanation
 Insufficient
observation time
 Inconsistent
vegetation
conditions (e.g.,
natural forage)
Preliminary Results: 2) Total Station Survey
• No significant difference among different width (0, 2,
and 4m) of buffer strips (P> 0.05)

29. Table 3 Robel height measurement in Fall 2020
Site
Buffer
strip
width
Mean
measurement
(cm)
Stdev (cm)
BDF
0 37.22 15.07
2 48.22 8.47
4 42.26 11.91
STC
0 38.84 15.89
2 61.50 11.66
4 44.67 12.74
YMC
0 33.81 11.85
2 53.38 13.00
4 48.68 17.06
Preliminary Results: 3) Robel height
Grass Robel height was significantly lower at 0-m ditches (p<0.05); no difference
between 2m and 4m vegetative filter strips.

30. Preliminary Results: Summary
• Both Total Station survey (manual) and LiDAR scan (UAV) in
2020 showed ditch volume decrease (sediment deposition), but
no significant difference among treatments (vegetative filter
strip width of 0, 2, and 4m) in the total station survey (though
lower % for wider buffer strip); LiDAR scan showed significantly
more deposition under 0-m strip than 2 and 4 m.
• 2021 data (completed in mid-Nov, under processing) showed a
reverse trend of ditch volume decrease (sediment loss, data no
shown). Needs further verification.
• Robel height followed our expectation (low at 0-m), and soil
and water quality data is under processing.
Treatment
/Site
2020 Ditch Sediment Deposition
2020 Robel Height (cm)
Total Station (m3) Total Station (%) LiDAR Scan (m3)
-------------------------------------------- Treatment (buffer width) --------------------------------------------
0M -50A -5.9%A -1560A 36.6B
2M -39A -6.1%A -364B 54.4A
4M -1A -1.4%A -466B 45.1AB
----------------------------------------------------- Sites -----------------------------------------------------
STC -23a -4.3%a -855a 48.3a
YMC -39a -6.5%a -505a 45.3a
BDF -29a -2.6%a -1030a 42.5a

31. Zhiming Qi, Ph.D.
James H. Brace Associate Professor​
Department of Bioresource Engineering​
McGill University
Email: zhiming.qi@mcgill.ca

32. Other information

33. Ditch volume calculation
-3
-2.5
-2
-1.5
0 1 2 3 4 5 6
-3
-2.5
-2
-1.5
0 1 2 3 4 5 6
-3
-2.5
-2
-1.5
0 1 2 3 4 5 6
Figure B.1 Ditch cross-section profile at Yamachiche 4m buffer strip ditch @ 340m in
2020 Oct and 2021 Jun
Figure B.2 Adjust them to achieve the equal ditch width
Figure B.3 Ditch volume illustration, resulting a volume difference of 24.305%
Other information

34. Field Survey
Cross sections measured in June and October in
4m vegetative buffer strip ditch at site Yamachiche

35. Table 2 Ditch Volume percentage change
from June 2020 to November 2021
• No significant difference among buffer strips (P> 0.05)
Total station survey
Site
Buffer
strip
width
(m)
Jun
2020 –
Nov
2020
Nov
2020 –
Jun
2021
Jun
2021 –
Oct
2021
Total(Jun
2020 –
Oct 2021)
BDF
0 -3.76% 3.40% 4.76% 4.247%
2 -5.22% 2.35% 0.99% -2.036%
4 -4.00% 4.87% 4.37% 5.079%
STC
0 -7.24% -1.32% -3.13% -11.336%
2 -9.83% 10.43% -3.83% -4.237%
4 -2.37% 26.73% 1.06% 25.050%
YMC
0* -6.80% 6.52% 11.41% 10.608%
2 -3.20% 6.41% 6.60% 9.804%
4 2.31% 3.12% -0.34% 5.136%
* Control ditch changed to the one on the east side of the old
control in 2020 due to dense vegetation along the old control.
Figure 2. Ditch volume percentage change comparison
between different buffer strip width over Jun 2020 to Nov 2021
• + sediment loss
• - sediment deposition
%𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑐ℎ𝑎𝑛𝑔𝑒 =
𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑎𝑡 𝑡ℎ𝑒 𝑒𝑛𝑑 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑟𝑖𝑜𝑑 − 𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑎𝑡 𝑡ℎ𝑒 𝑠𝑡𝑎𝑟𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑟𝑖𝑜𝑑
𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑠𝑡𝑎𝑟𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑟𝑖𝑜𝑑

36. Site
Buffer
strip
width (m)
Growing*
Season
2020
Non-
growing*
Season
2020
Growing*
Season
2021
BDF
0 -3.76% 3.40% 4.76%
2 -5.22% 2.35% 0.99%
4 -4.00% 4.87% 4.37%
STC
0 -7.24% -1.32% -3.13%
2 -9.83% 10.43% -3.83%
4 -2.37% 26.73% 1.06%
YMC
0* -6.80% 6.52% 11.41%
2 -3.20% 6.41% 6.60%
4 2.31% 3.12% -0.34%
• Growing season has less
impact on ditch’s volume
than the fallow season.
(p=0.004, w=27, One -tailed
Mann-Whitney U test)
Figure 1. Ditch volume percentage change
comparison between growing and fallow
season
Total station survey
* Control ditch changed to the one on the east side of the old
control in 2020 due to vegetation along the old control.
* Growing season 2020: Jun 2020 – Nov 2020
* Non-growing season 2020: Nov 2020 – Jun 2021
* Growing season 2021: Jun 2021 – Oct 2021
Table 3 Ditch Volume percentage change
from June 2020 to November 2020
18 9
%𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑐ℎ𝑎𝑛𝑔𝑒 =
𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑎𝑡 𝑡ℎ𝑒 𝑒𝑛𝑑 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑟𝑖𝑜𝑑 − 𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑎𝑡 𝑡ℎ𝑒 𝑠𝑡𝑎𝑟𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑟𝑖𝑜𝑑
𝐷𝑖𝑡𝑐ℎ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑠𝑡𝑎𝑟𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑟𝑖𝑜𝑑
• + sediment loss
• - sediment deposition

37. NDVI of site
Yamachiche
NDVI of site
St Cuthbert
Vegetation measurement