1.
Development of Remote Sensing
Techniques to Map Drainage Tiles in
the Prairie Pothole Region of Iowa
Jim Giglierano
Wisconsin Dept of Administration
jim.giglierano@wi.gov

2.
Final Contractor Report: Development of Remote Sensing
Technologies to Characterize Drained (Farmed) Wetlands in
the Prairie Pothole Region of Iowa
EPA WPDG CD97731601
James D Giglierano (principal investigator), Emily Milton, Ligia de Oliveira Serrano, Amy Logan,
Robin McNeeley, Kevin Kane - Iowa State University
Sherry Torres, Xiaodan Chen - University of Iowa
Michelle Fields, Greene County Drainage Clerk/GIS
Chris Ensminger, Pete Kollasch, Matt Swanson, Calvin Wolter, Andy Asell - Iowa Department of Natural Resources
Aerial Contractors: Aerial Services, Inc. and GeoVantage, Inc.
December 20, 2015
IOWA STATE UNIVERSITY, GIS SUPPORT AND RESEARCH FACILITY
IOWA GEOLOGICAL AND WATER SURVEY, IOWA DNR
US EPA REGION 7, WETLAND PROGRAM DEVELOPMENT GRANT

3.
Water table under normal conditions
Water table after heavy rainfall

4.
Color infrared ortho-photo acquired on 4/29/2007, 3 days after 3+” rain.

5.
Previous research by Naz and Bowling (2008) in central Illinois
“tiles were visible after rainfall events greater than 1 inch in 24 hours. The optimum time
for flights was 2-3 days after such events, in the spring season when the ground is most
free from vegetation and residue cover.”

6.
Locations of project test
areas in Greene, Wright
and Hamilton Counties,
Iowa.

7.
Locations of small test sites

8.
Wright County test area repeatability test.
April 29, 2007 CIR Ortho May 31, 2013 Color Ortho Tiles mapped from 2013 image

9.
Lyons Creek test area in
Hamilton County,
flown on 5/31/13

10.
Lyons Creek test area in
Hamilton County,
flown on 5/31/13

11.
Close up view of Lyons Creek test area in Hamilton County, image collected
5/31/13 by ASI, 4 days after 1.67” rainfall event, with a 10 day rainfall accumulation
of 4.28”.

12.
Aerial image collected 4/20/13 over Greene County test area. Taken 2 days after a 1.82” rainfall event
which meets the initial flight criteria > 1” rain, but <50% of tiles visible. Ten day rainfall total 2.6”. Ground
not saturated enough for tiles to show up.

13.
Aerial image collected 5/31/13 over Greene County test area showing light and dark cloud shadow
patterns. Plane flew under clouds one day after 1.56” rainfall to collect imagery. Ten day accumulation
was 6.94” which was too wet.

14.
Final aerial image collected 6/18/13 over Greene County test area. This flight was 3 days after a 1.74”
rainfall event which should have met the original flight criteria of 3 days after 1” plus event. Ten day rainfall
accumulation was only 2.29”. All the tiles visible from all three flights are shown in red on this slide.

15.
Greene County test area with imagery from 4/29/13. Comparison of mapped tile
patterns with actual GPS locations of installed tiles. Overall, tile pattern and
location are very similar.
April 20, 2013 Color Ortho
showing tile patterns.
Mapped tile patterns.
GPS locations of installed
tiles from drainage
contractor.
Comparison of mapped tile
patterns with GPS
locations.

16.
Basic Mapping Criteria for Tile Mapping on the PPR
1. Tiles can be fully mapped with 7-10 day total rainfall accumulations of 4-8 inches and flights 3-5
days after the last significant rainfall. Conditions may also be good for 7-10 day total accumulations
of 3-4 inches and flights 2-3 days after last significant rainfall over 1 inch.
2. Tiles can be partially mapped with 7-10 day total rainfall accumulations of 2-3 inches and flights 2-3
days after last significant rainfalls over 1 inch.
3. Tiles cannot be mapped with 7-10 day accumulations less than 2 inches, even with a 1 inch plus
event and a flight 2-3 days afterward.

17.
May 18th, 2014
10 day
accumulations

18.
June 24th, 2014
10 day
accumulations

19.
Figure 3.1a 2000-2015 (up to July 1, 2015) rain gage data from the Algona, Iowa NWS COOP station in the northern part of the PPR. Daily
rainfall totals were added up over 10 days. Chart shows very few 10 day accumulations over 4 inches each year, with some years having no
events and some have 2-3 events.
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

20.
Figure 3.1b 2000-2015 (up to July 1, 2015) rain gage data from the Webster City, Iowa NWS COOP station in the middle part of the PPR.
Daily rainfall totals were added up over 10 days. Chart shows very few 10 day accumulations over 4 inches each year, with some years
having no events and some have 2-3 events.
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

21.
Figure 3.1c 2000-2015 (up to July 1, 2015) rain gage data from the Perry, Iowa NWS COOP station in the southern part of the PPR. Daily
rainfall totals were added up over 10 days. Chart shows very few 10 day accumulations over 4 inches each year, with some years having no
events and some have 2-3 events.
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

22.
Estimates for Tile Mapping the PPR
Based on imagery costs of $50 per square mile for 30cm imagery
1. Worst case: five years to map entire PPR, double coverage of imagery, labor
for mapping and contract administration, total of about $1.6M
2. Best case: three years, single coverage of imagery, labor for mapping and
contract administration, total of about $800k

23.
A PHOTO INTERPRETATION MANUAL
FOR MAPPING AGRICULTURAL DRAINAGE TILES
EPA WPDG CD97731601
Emily Milton and Ligia de Oliveira Serrano
Iowa State University GIS Support and Research Facility
Sherry Torres, Xiaodan Chen and Jim Giglierano (principal investigator)
Iowa Geological and Water Survey, Iowa Department of Natural Resources

24.
Parallel Tiles

25.
Herringbone Tiles

26.
Random Tiles

27.
Mixed Tiles

28.
Newly Installed Tiles

29.
Vegetated Tiles

30.
Faux Tiles

31.
Close up image showing a pothole with a tile
intake in the center (lighter orange pixels).
Tile Intakes

32.
Another close up
image showing a
pothole with a tile
intake in the center
(lighter orange
pixels).

33.
Close up
image
showing tile
outlet into
drainage
ditch

34.
5/14/14
Beaver Creek, Chickasaw Co, IA

35.
THANKS!
Jim Giglierano
jim.giglierano@wi.gov

36.
Project Folder
https://drive.google.com/drive/folders/0BxoxDkTBNIfzYTByeU5fa2lBMGc?usp=sh
aring

37.
Development of Remote Sensing Techniques to Map Drainage Tiles in the Prairie Pothole Region of Iowa
Previous research in the Midwest indicated that agricultural drainage tiles could be mapped through traditional remote sensing techniques. Photo-
interpretation of color infrared aerial photographs could be used to map tiles 2 to 3 days after a 1 inch rainfall or more. This scenario was extensively
tested between 2012 to 2015 in the Prairie Pothole Region (PPR) of Iowa by staff and students at the Iowa Geological and Water Survey and Iowa
State University GIS Facility. Results from several flights over target areas in the PPR showed that optimal conditions there were more stringent, and
required a 10 day rainfall accumulation of more than 4" in order to completely saturate the soil profile. After waiting 3 to 4 days for stream levels to
recede, the effects of tile drainage became visible at the land surface and were easily photographed from the air with 1 meter or better color or color-
infrared imagery. The chance of occurrence of these >4 inch rainfall periods in the spring is small in any one year for a particular target area.
Arranging for aerial coverage in advance was not difficult, though planes were not be always available on one or two day notice when actual
conditions were met. In addition, identifying where local soil moisture conditions were optimal was extremely challenging using rainfall accumulation
databases and models available on the Internet from NOAA and university researchers. Overall, this effort showed that tile mapping projects are
possible over a multi county area in the PPR, but 2 to 5 years may be required to fully cover all areas within the project area of interest due to local
variations in rainfall patterns, aircraft availability and other unforeseen circumstances. A photo-interpretation guide for identifying and mapping tile
patterns was also assembled during this project.