Spatial Model of Flood Inundations in Moorhead and East Grand Forks Minnesota
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Transcript of Spatial Model of Flood Inundations in Moorhead and East Grand Forks Minnesota
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Using ArcGIS to Model Flood Inundation and Impact
Near East Grand Forks and Moorhead, Minnesota
GIS 5578 GIS Programming
Matt Taraldsen, Josh Dunsmoor
1.Project IntroductionFlooding is both the most common and the costliest natural disaster in the United States
(FEMA). From 2000 2010, a yearly average of $2.6 Billion of flood damage was
reported, as well as an average of 71 deaths (National Weather Service). Damage
caused by flooding not only includes automobiles and houses, but sometimes entire
cities may experience significant damage. Once such area with high susceptibility to
flood risk is the Red River of the North Basin. This area experiences nearly annual flood
stage readings, and boasts a record crest of nearly 41 feet, experienced in 2009 near
Fargo, North Dakota and 54 feet, experienced in 1997 in the Grand Forks area (North
Dakota State University). The purpose of this study was to build a model in ArcGIS,
which features an ASCII DEM file as an input to produce inundation maps. The
inundation maps would then be overlaid on Tiger Census data to gauge potential
population impacts.
The motivation for this project comes from mutual interest of natural disaster response
and mitigation. Matt has a background in meteorology, while Josh has a strong interest
in using GIS in disaster modeling and mitigation. This project will allow not only for
modeling of the natural processes of flooding, but also allow an estimation of
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inundations at different flood levels. By integrating population data in this study, we can
learn the potential impacts to the areas population.
Further justification of the project comes from the large impacts associated with
flooding. As stated above, flooding is a major issue in the Red River Valley, and utilizing
GIS allows for further analysis of flooding potential. This project also presents an
opportunity for professional development of both group members. As a meteorologist,
Matt would like to conduct flood studies in a professional environment after graduation,
and Josh would like to apply his risk management perspective to manage and mitigate
disaster using GIS. This study would facilitate GIS skill development in natural sciences
and potential environmental impacts.
2.Background DataThe purpose of this project will be to develop a simple model demonstrating flood
inundation based from a DEM file. Several more complicated studies have been
conducted and were used for reference in this project. The forecasting and monitoring
of floods is a federally mandated task of the National Weather Service (Department of
Commerce, 2010). The forecasts, warnings, and advisories issued by the National
Weather Service are intended for use to mitigate the threat to life and property posed
by events such as floods. For this model, the focus has been given to river flooding
which is high flow, overflow, or inundation by [river] water which causes or threatens
damage (Department of Commerce, 2010). This is separated from flash flooding, which
occurs within six hours of a caustic event and usually arises from events such as
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thunderstorms. The National Weather Service further defines the levels of flooding
(Table 1).
National Weather Service Flood TerminologyTerm Definition
Monitor/Action
Stage
Bank full condition. NWS will issue flood forecasts, and monitoring of levee and other
protection systems mandatory.
Flood Stage Minimal or no property damage - but public threat.
Moderate
Flood Stage
Some inundations of roads and structures near streams. Some people or property
relocated to higher ground.
Major Flood
Stage
Extensive inundation of structures and roads. Significant evacuations of people to
higher elevations.
Record Flood
Stage
Flooding equals or exceeds previous maximum flood stage for a given location. Not
necessarily above other flood stages.
Table 1 - National Weather Service flood terminology (Dept. of Commerce, 2010)
Flood stages are then quantitatively assigned to a given flood area based on the
impacts listed above. The stages will be assigned by the local National Weather Service
forecast office, and corresponding area River Forecast Center (Dept. of Commerce,
2010).
Flood Stages are occasionally altered as new data is available. Due to the frequent
flooding in the Red River valley, new data is available. Lidar data has recently been
collected for the Red River Valley (MN Geospatial Intelligence Office, 2012). Table 2
illustrates the current flood stages for the Fargo and Grand Forks area (National
Weather Service, 2012). These flood stages were assigned in 2010 (Grand Forks) (FEMA,
2010), and 2012(Moorhead) (FEMA, 2012).
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Flood Information for Fargo and Grand Forks (in feet)Gauge
Elevation
Action
Stage
Flood
Stage
Moderate
Stage
Major
Stage
Record
Crest
Fargo 861 17 18 25 30 41
Grand
Forks 779 27 28 40 46 54Table 2 - Flood Data for Grand Forks and Fargo (From National Weather Service, 2012)
Both Grand Forks and Moorhead have had major flood events in the past. For a
comparison of how the predicted major and record floods compared, record (at the
time) crests in 1997 and then again in 2009 will be utilized.
3.Area of Interest
The study focused on the red river in three counties in Minnesota: Polk, Norman and
Clay. Within these counties are the cities of East Grand Forks and Moorhead, both of
Figure 1 - Clay, Norman, and Polk Counties with population centers. East Grand Forks and Moorhead are
highlighted
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which have experienced major flooding in both 1997 and 2009. In 2000, Moorhead had
a population of 38,000, with a Fargo-Moorhead metro population of 174,000 residents.
East Grand Forks had a population of 7,500, and 60,000 in the wider Grand Forks-East
Grand Forks area (US Census). MN DNR 30m DEMs were secured for both the Grand
Forks and the Moorhead areas. As these two cities represent the largest population
centers along the Red River, they will be the primary focus for this survey.
4.MaterialsData utilized in this project came from the Minnesota Department of Natural Resources
(DNR) Data Deli (http://deli.dnr.state.mn.us/). North Dakota does not widely distribute
data, and the data that was located did not correspond with the area of interest. An
attempt was made to obtain Lidar data from the Red River Decision Information
Network (http://gis.rrbdin.org/lidarapps.htm), however, data usage was limited on the
site and lidar data was not easily accessible. The decision was made to download the
30 meter resolution DEM from the Minnesota DNR. Raw ASCII files were downloaded
for the East Grand Forks and Moorhead, Minnesota area.
In addition to the flooding inundation, this project also intends to view the potential
impacts of flood stages. Once the DEM was secured, 2010 Census population data
(http://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.html )was downloaded. This
includes population and population density data. These data were overlaid with the
inundation polygons to create and estimate of impacted population.
http://deli.dnr.state.mn.us/http://deli.dnr.state.mn.us/http://deli.dnr.state.mn.us/http://gis.rrbdin.org/lidarapps.htmhttp://gis.rrbdin.org/lidarapps.htmhttp://gis.rrbdin.org/lidarapps.htmhttp://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.htmlhttp://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.htmlhttp://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.htmlhttp://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.htmlhttp://gis.rrbdin.org/lidarapps.htmhttp://deli.dnr.state.mn.us/ -
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While a majority of sources and data were found online, they represent the most
accurate and official documentation of the US Government. The National Weather
Service maintains all of their data online to ensure Emergency Management, storm
spotters, other meteorologists, or any other interested party can easily and readily
access the data. The data on these websites is considered official
climatic/meteorological data from the National Weather Service. Paper copies are only
available for purchase from the National Climatic Data Center (NCDC), and currently are
not available through the University of Minnesota. Due to the lack of budget for the
project, the decision was made to only use publicly accessible online data.
5.Data PreparationMethodology for this paper was to combine ArcGIS Model Builder with custom scripts
from Python to develop a working model. Once the data was collected from the DNR
and the Census Bureau, the next step was to create an Area of Interest. Data from the
DNR was centered on both Moorhead and East Grand Forks. The Moorhead area was
represented by one raster while the Grand Forks area was covered by two separate
rasters. The first step was to mosaic these two rasters to create two files to represent
the area of interest.
The decision was then made to keep the two rasters separate as they both
represented different parts of the river. The Red River slowly decreases in elevation as it
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flows north, with the gauge at Fargo located 861 feet and the Grand Forks gauge at 779
feet above sea level. Table 2 illustrates the flood elevations for each stage, in each city.
These values were utilized in custom python scripts to select impact areas.
6.MethodologyOnce the data and research was complete, the decision was made to use Model Builder
to build rasters. By using Model Builder, any DEM for another location could be used for
similar study. The Grand Forks mosaic DEM raster was ingested into model builder, and
converted from an ASCII file to a point file (Figure 2). This was time intensive, but
allowed for a selection of the different elevations from the raster file. A similar approach
was taken with the Moorhead area (Figure 3)
Figure 2 - Model Builder for Initial Grand Forks Setup
Figure 3 - Model Builder for the Initial Moorhead Setup
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Two python scripts, one for each city, (Appendix 1 and 2) were developed to take the
converted point raster and select all the points from the different flood elevations from
Table 1. These selected layers are then converted to an individual raster. These
individual rasters will represent the inundation levels for the different flood stages
around Moorhead and Grand Forks.
Figure 4 - Moorhead Model Builder
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Figure 4 and Figure 5 illustrate the next step in the model builder. Once the scripts
(Appendix 1 and 2) created five separate rasters the next step was to transform them.
Model builder was them employed to complete the following:
A) Convert the point files into a rasterB) Convert the raster into polygonsC) Aggregate the polygon layers (100m radius) to create a solid polygon layerD) Intersect the aggregated polygons with the census tracts to form an impacted area
The model was designed to build successively off of each layer. Therefore, most layers
featured the previous iteration of the model as input. Table 2 lists each step with input
and output parameters. Also included is a remarks column, stating the intended use of
each layer. The impacted area will then feature not only the DEM data but also the
Figure 5Grand Forks Model Builder
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census data including housing and population data. This will provide an estimation of
the impacts of a flood at different levels.
Grand Forks/Moorhead Model Steps
Model Layer Input Parameters
Output
Parameters Remarks
Step 1
GF DEM N/A N/A raw ASCII DEM file
Raster to Point
GF/ Moorhead DEM
ASCII file Point Raster
Converts ASCII raster to a
point raster
Grand Forks
Script/Moorhead Point Raster
GF/Moor Action
PointsGF/Moor Major
Points
GF/Moor Record
Points
GF/Moor Moderate
Points
GF/Moor Flood
Points
Takes the point file and
selects attributes based on
individual flood elevations.
Individual selections are then
saved as flood layers.
Completed with arcpy script
(Appendix 1)
Step 2
Point to Raster (x5)
GF/Moor Action Points
GF/Moor Major Points
GF/Moor Record
Points
GF/Moor Moderate
Points
GF/Moor Flood Points
GF/Moor Action
RasterGF/Moor Major
Raster
GF/Moor Record
Raster
GF/Moor
Moderate Raster
GF/Moor Flood
Raster
Converts point files
into a raster.
Raster to Polygon (x5)
GF/Moor Action
Raster
GF/Moor Major Raster
GF/Moor Record
Raster
GF/Moor Moderate
Raster
GF/Moor Flood Raster
GF/Moor Action
Polygon
GF/Moor Major
Polygon
GF/Moor Record
Polygon
GF/Moor
Moderate Polygon
GF/Moor Flood
Polygon
Converts raster into
polygon layers
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Aggregate Polygons
(x5)
GF/Moor Action
Polygon
GF/Moor Major
Polygon
GF/Moor Record
Polygon
GF/Moor Moderate
Polygon
GF/Moor Flood
Polygon
GF/Moor Action
Polygon
Aggregated
GF/Moor Major
Polygon
Aggregated
GF/Moor Record
Polygon
Aggregated
GF/Moor Moderate
Polygon
Aggregated
GF/Moor Flood
Polygon
Aggregated
Combines all Polygon Layers
into one large polygon for
overlay
Intersect (x5)
GF/Moor Action
Polygon Aggregated
GF/Moor MajorPolygon Aggregated
GF/Moor Record
Polygon Aggregated
GF/Moor Moderate
Polygon Aggregated
GF/Moor Flood
Polygon Aggregated
Grand Forks Census
Tracts (GF only)
Moorhead Census
Tracts (Moorhead only)
GF/Moor Action
Impacted Area
GF/Moor Flood
Impacted Area
GF/Moor Moderate
Impacted Area
GF/Moor Major
Impacted Area
GF/Moor Record
Impacted Area
Intersects the census tract
information
with the aggregated
polygons. Impacted
population tallys can then be
extracted from
the attributes table.Table 2 - Model input and output parameters and remarks
7.Data ErrorsData collection proved to be the most challenging part of the project. North Dakota in
particular did not have data readily available. The Minnesota DNR did have data available,
but was in a different format from the available Census data. All files have a projection of
Transverse Mercator in the NAD 1983 UTM 15N coordinate system.
The next issues were the large size of the files utilized, and file types. Initially the project
was intended to ingest a raster data and select attributes from this file. However, once
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the DNR ASCII file was downloaded this was no longer an option. Upon investigation
into other flood projects from the University of Texas (Lopez, 2003) it was found a point
layer would be sufficient to select attributes from. However, this point layer created a
large file that took over 30 minutes to render in model builder. This slowed down the
project considerably but gave more representative elevation results.
8.Preliminary ResultsFigure 6 illustrates the amount of flooding near East Grand Forks at different levels. Of
note was the large spatial extent of the major flood stage polygon. The bottom left of
Figure 6 illustrates the amount of the city of East Grand Forks is inundated in a major
flood. Nearly the entire city is inundated in a major flood with only minor additional
flooding from the record crest. This is validated by the fact that after 1997 flood, all but
eight homes were damaged by flood waters in East Grand Forks. When compared to
Moorhead, it appears that the northern edge of East Grand Forks is especially
susceptible to widespread inundation. While the areas covered by both the major and
record floods are significant, the areas are likely exaggerated in the model. The areas
north of East Grand Forks have a lower elevation than the gauge within the city limits,
and our model cannot account for those immediate changes. Even with the northernly
bias, it is clear that major sections of East Grand Forks (over 10,000 people) would be
directly impacted by a major or record flood. This is consistent with both the major
floods of 1997 and 2009.
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Figure 6 - Flood levels near East Grand Forks, MN
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East Grand Forks ImpactsAction Stage Flood Stage Moderate Flood Major Flood Record Flood
Population Impacted 2322 3257 3977 10823 10889
% Increase from Previous NA 140.27% 122.11% 272.14% 100.61%
Area Covered (ha) 1405 4059 7137 22505 23932
% Increase from Previous NA 288.90% 175.83% 315.33% 106.34%
Table 3 - Grand Forks Impact
Unlike Grand Forks, which had an immense flooding impact within the city, Moorhead was relatively
unscathed by flooding. Most of the flooding (bottom Figure 6) inundates the areas to the north of the
city which is comparatively sparsely populated. There is still some inundation within the city, but
compared to Grand Forks there is a comparatively smaller area covered. A quantitative result is
displayed in table 4. As in Grand Forks, the Moorhead area also shows a large area of inundation north
of the city. Some of this may again be due to the lower elevation of the river as it flows north, but
historic flood maps show areas to the north of the city are more susceptible to flooding. The inundated
areas north of the city are likely exaggerated, but unlike Grand Forks these areas are sparsely populated.
This limited the amount of populations that were impacted in the model. However, as with Grand Forks,
a record or major crest has a very large impact. The model estimated that nearly 18,000 people would
be impacted by flood waters in a record crest. In a major flood this number is slightly less, but still over
15,000 people are likely to be significantly impacted by flood inundation. Again, this is consistent with
the major floods of 1997 and 2009.
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Figure 7 - Flood stages in Moorhead, MN
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Moorhead Impacts
Action
Stage
Flood
Stage
Moderate
Flood
Major
Flood
Record
Flood
Population Impacted 3764 4556 4994 15876 17966
% Increase from
Previous NA 121.04% 109.61% 317.90% 113.16%
Area Covered (ha) 939 3697 8394 20821 22177
% Increase from
Previous NA 393.72% 227.05% 248.05% 106.51%
Table 4 - Flooding Impacts in the Moorhead Area
9.Model TestTo ensure the model was applicable to other situations, a test run was conducted. While the
flood stages utilized in the paper were the most recent, there was theoretically still some error
in the model. By using a 30m resolution DEM, at least some error is generated in the inundation
fields. The difference between the use of lidar generated DEM, and larger scale DEM can
sometimes be rather significant. (Wang et. al, 2010). Not only can there be error in the
measured DEM, but our model also did not capture the dynamics of a flood (Erich et. al, 2002).
As a flood progresses, there are often strong dynamics besides the simple inundation of
structures. This includes the potential for multiple crests, flood control efforts of the affected
municipalities, and environmental sources such as ice in the channel or wave action. Therefore,
a hypothetical flood was generated in our model. This flood will be 1 foot above all current
levels (Table 5). This tested the potential impact of just a one foot change in flood elevation due
to the dynamics of moving water. The same methodology was followed as the original run, but
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all levels in the model were increased by one foot.
Figure 8 - Test run comparison to first run output
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Test Stages for Fargo and Grand Forks (in feet)
Gauge
Elevation
Action
Stage
Flood
Stage
Moderate
Stage
Major
Stage
Record
Crest
Fargo 861 18 19 26 31 42
Grand
Forks 779 28 29 41 47 55Table 5 - Fargo and Grand Forks Test Values
The same methodology was used for the test run as with the first run of the test
(Section 6). The scripts were altered to reflect the new levels, and then run (Figures 10
and 11). A new model was then created, which analyzed all ten flood stages for both
Figure 9 Fargo/Grand Forks test model
Figure 11 - Test script for MoorheadFigure 10 - - Test script for Grand Forks
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locations at one time. The model followed the same methodology as the first model set
up, just with new test layers for outputs.
The test revealed a few interesting trends. First, as expected there were large increases
in impacts for both the major and record crest. What was surprising was that there was
actually less of an impact if the action and flood stages were raised. This was not
expected, and the model was run several times to ensure these results are correct. It is
speculated by the group that this error is a byproduct of the intersection of the flood
layers with the census tracts. With the new stage, a different set of intersections were
created which may have altered which census tracts were impacted. This would alter
the population totals for each stage.
Moorhead Test ImpactsAction
Stage
Flood
Stage
Moderate
Flood
Major
Flood
Record
Flood
Population Impacted 3764 4556 4994 15876 17966Test population
impacted 3874 3721 4598 17444 18881
% Change 102.92% 81.67% 92.07% 109.88% 105.09%
Area Covered (ha) 939 3697 8394 20821 22177
Test Area Covered (ha) 1031 4094 9613 21586 23011
% Change 109.80% 110.74% 114.52% 103.67% 103.76%Table 6 - Moorhead test results
Grand Forks Test Impacts
ActionStage
FloodStage Moderate Flood
MajorFlood
RecordFlood
Population Impacted 2322 3257 3977 10823 10889
Test population impacted 2181 2266 3981 10857 11127
% Change Population 93.90% 69.60% 100.10% 100.30% 102.20%
Area Covered (ha) 1405 4059 7137 22505 23932
Test Area Covered (ha) 1328 3664 8482 21716 23545
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% Change Area 94.52% 90.27% 118.85% 96.49% 98.38%Table 7 Grand Forks test results
With the exception of the errors with some stages having inconsistent impacts the model
worked well. The largest changes were seen in the major flood category, where a nearly 10%
greater impact was noted by increasing the crest by just one foot. In Grand Forks the changes
were comparatively small, but there was a 2% change in the population impacted when the
record crest was adjusted upwards by one foot. Significant increases in Moorhead were also
noted in are inundated between flood stages. The biggest increase was from flood to moderate
flood stage, which increased the inundation area by 14%.
10. Final Conclusions
For both Grand Forks and Moorhead, the results were consistent with what were expected.
While there were some inconsistencies with the population impacts between the various flood
stages, the model clearly created polygons that increased in spatial coverage as the flooding
became more significant. Also of note was the large amount of area inundated and people
impacted for both the major and record floods. While this was likely biased to the river
naturally decreasing in elevation away from the gauge sites, having over 10,000 people
impacted in Grand Forks and over 17,000 in Moorhead was still indicative of a high impact flood
event. The use of python and model builder were especially useful for this project. The python
script allowed for a relatively rapid collection and generation of the raster layers, which would
have taken considerable more time for a human analyst to complete. The model builder, while
sometimes cumbersome, allowed for all flood layers to be generated simultaneously, and again
saved time. For future research the inclusion of higher resolution lidar data would be desired
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as a comparison of the two data sources could then be completed. Also, including information
about the flood levies in both Grand Forks and Moorhead would be valuable as a much more
accurate inundation map could be produced. Additional analysis of the census data could also
be performed to mitigate and plan response for future floods. Using the data to locate elderly
or under-privileged populations would allow emergency crews to focus early efforts in their
direction. Finally, including more in depth information about soil infiltration, timing of
inundation in different weather conditions, and also dynamically mapping the flood inundation
are all potential areas of research but were not achievable with the methodology of this
particular project.
11.Task ContributionsThe proposal for this project was a collaboration of the two of us as we both drew on our
interest in natural disaster management. Given Matts meteorological experience, he
determined the needed data sets and sources. Once data was collected, it was passed off to
Josh who developed the work flow needed to get from the input ASCII file to our output
flood stage raster files. With the workflow determined, the model was assembled in model
builder by Matt, and the manual scripting needed to develop the flood stage selections was
written by Josh. From there, it was a collaborative effort to display the information and
report and display the findings.
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Appendix:
Appendix 2: Python code for selecting Moorhead data
## Date: 4/22/2012
## This tool will query the point shape file storing the elevation data. This script will
## query the points, create the selections, and write the output files for creating
## the flood level polygons in Moorhead. There are 5 flood levels, action, flood, moderate
## major, and record.
import arcpy
import sys
arcpy.env.Workspace = "E:\Programming\Project_Data\moorhead_point.shp"
inFC = arcpy.env.Workspace
moorElev = 861
outAction = "E:\Programming\Project_Data\Output_Rasters\moor_outaction.shp"
outFlood = "E:\Programming\Project_Data\Output_Rasters\moor_outfld.shp"
outModerate = "E:\Programming\Project_Data\Output_Rasters\moor_outmod.shp"
outMajor = "E:\Programming\Project_Data\Output_Rasters\moor_outmjr.shp"
outRecord = "E:\Programming\Project_Data\Output_Rasters\moor_outrec.shp"
arcpy.Select_analysis (inFC, outAction, '"GRID_CODE" < 879')
arcpy.Select_analysis (inFC, outFlood, '"GRID_CODE" < 886')
arcpy.Select_analysis (inFC, outModerate, '"GRID_CODE" < 891')
arcpy.Select_analysis (inFC, outMajor, '"GRID_CODE" < 902')
arcpy.Select_analysis (inFC, outRecord, '"GRID_CODE" < 903')
Appendix 2: Python code for selecting Grand Forks data
## Date: 4/22/2012
## This tool will query the point shape file storing the elevation data. This script will
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## query the points, create the selections, and write the output files for creating
## the flood level polygons for the East Grand Forks, MN area. There are 5 flood levels,
action, flood, moderate
## major, and record.
import arcpy
import sys
arcpy.env.Workspace = "E:\Programming\Project_Data\grand_forks_point.shp"
inFC = arcpy.env.Workspace
moorElev = 861
outAction = "E:\Programming\Project_Data\Output_Rasters\gf_outaction.shp"
outFlood = "E:\Programming\Project_Data\Output_Rasters\gf_outfld.shp"
outModerate = "E:\Programming\Project_Data\Output_Rasters\gf_outmod.shp"
outMajor = "E:\Programming\Project_Data\Output_Rasters\gf_outmjr.shp"
outRecord = "E:\Programming\Project_Data\Output_Rasters\gf_outrec.shp"
arcpy.Select_analysis (inFC, outAction, '"GRID_CODE" < 807')
arcpy.Select_analysis (inFC, outFlood, '"GRID_CODE" < 819')
arcpy.Select_analysis (inFC, outModerate, '"GRID_CODE" < 825')
arcpy.Select_analysis (inFC, outMajor, '"GRID_CODE" < 833')
arcpy.Select_analysis (inFC, outRecord, '"GRID_CODE" < 834')
Appendix 3: Location of Files
File name, sub-folders, and remarks within Programming File
Folder Name Sub-Folder Remarks
Census Data Contains raw census data
Flood Maps Contains all figures of flood inundation utilized in paper
Scripts Contains all arcpy scripts utilized
MN_Data Contains raw data from MN DNR data deli
MN_Data MN Counties Shapefile of MN county outlines
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MN_Data MN Cities Shapefile of MN municipal boundaries
Model Figures Contains figures from model builder
Project_Data Grand Forks and Moorhead point files
Project_Data Aggregated_Polygons Final layer of polygons before overlaid with census tracts
Project_Data Grand Forks DEM Raw ASCII DEM file for Grand Forks
Project_Data Intersected_Pop
The final layer of the model - combined census tracts and
aggregated polygons for both Grand Forks and Moorhead
Project_Data Moorhead DEM Raw ASCII DEM file for Moorhead
Project_Data Output_Raster Converted raster layers to polygons
Project_Data Temp_Rasters Converted point files into raster layer
Project_Data Toolbox
Contains python scripts and model builder files
utilized in the model
Works Cited
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"Census 2000 TIGER/Line Data." Free Data. ESRI Corporation. Web. 22 Mar. 2012.
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POTENTIAL IN CHESTATEE RIVER WATERSHED." Gainesville State College. Proc. of E 2009
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"The USGS Land Cover Institute (LCI)." The USGS Land Cover Institute (LCI). United States Geological
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Wang, C., T. Wan, and I. Palmer. "Urban Flood Risk Analysis for Determining Optimal Flood Protection
Levels Based on Digital Terrain Model and Flood Spreading Model." Visual Computer 26.11
(2010): 1369-81. Web.