ESPM 5295 - Applied GIS in Natural Resource Management

This page organizes all the main course information and is used to distribute assignments and data sets. Throughout these pages, links are underlined.

Mandatory class participation days (in person or on zoom) are noted at the start of each week. 

Class materials are organized sequentially in accordion drop-downs, first activities, then deadlines, and finally resource

Canvas site for ESPM5295 - Used to turn in assignments, track grades

- Paul can be reached at [email protected], or 612 889-9136, or Paul's Zoom Link 

-  Andy Jenks can be reached at [email protected]  or 651-387-9600, or  Andy Jenks' Zoom Link

Each week is a set of three "accordions," which will expand when you click on the plus sign on the right. The assignments are described in the first, due dates in the second, and resources for the week in the third accordion. Use this information to complete each week's tasks.

Note that if you click on a link in one of the accordions it will sometimes open the link in this same tab, and sometimes it will open a new tab. It depends on how your browser is configured.  If you click the back button to this page, you may find the accordion closed, losing your place.  To avoid this, in Chrome, and many other browsers, you may right click on a link, and it will give you a choice to open the link in a new tab. A command-click or control-click will often do the same thing. If you find yourself doing this a lot and tire of it, then you may wish to search how to configure your browser to by default open in a new tab.

Schedule and Content

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Sept. 7, Week 1 Assignment - Project Introduction, Software Setup, Course Mechanics

Mandatory Class Meeting on Wednesday

Week 1 - Introduction, Course Mechanics, ArcGIS Set Up and Use
Our primary goals this week are to cover course mechanics, for you to set up and verify ArcGIS Pro and class data access from home, refresh basic ArcGIS use and digitizing, and introduce our semester-long problem spatial analysis project. Whew.

This course is split into two periods. We develop skills during the first five or so weeks, focusing primarily on practice areas in the northern part of the St Paul Campus. The remainder of the semester focuses on analysis for two project watersheds for an expanded area (map here).

 

ArcGIS Software Access     

There are three ways to access the software.

The easiest and perhaps least convenient involves coming to our lab (35 Skok or 210A Green Hall).  Everything works, limited access evenings and weekends, schedule on the door.

A second route accesses ArcGIS Pro via the web, with an app that gives access to a virtual computer. We will use a software called Citrix Workspace/AppsToGo.

AppsToGo allows you to start a MS Windows virtual machines (VM) in most browsers, on most computers.  When we say VM in this class, we mean an ephemeral computer that runs on the cloud, and goes away when you close AppsToGo. It is a virtual instance of a computer, with all windows capabilities, running on a larger computer elsewhere. 

You have to copy data to the VM and work on it there, then copy your results back to a more permanent cloud or local drive, as all is lost when the VM is closed.

See videos/documents  in the resources section below regarding VM and data management.

Using a VM requires a fast and reliable internet connection

The third way is to install ArcGIS Pro on your home or lab computer (see Andy, need a fast computer, and some restrictions apply).

 

To do this week:

A) Scan the Semester Project Description linked here, to get an idea of what we're heading for over the next 15 weeks, and look at the Rainfall Mitigation description and the Minnesota Pollution Control Agency guidelines, and this Minute Earth video on the coming "poopocalypse" for additional motivating information.

B) Set up access to ArcGIS Pro via a virtual machine/web browser, OR install ArcGIS Pro on a home machine, using the instructions found in the link to the X295 Software Setup, in the resources accordion, below. 

C) Create and digitize into a practice geodatabase in NAD83(CORS96/2011) UTM Zone 15 coordinates.  Refer to the materials in the resources accordion, below, if you need a refresher in getting started in ArcGIS Pro. If you still have questions, talk to Paul and Andy. We'll expect you to be able to create geodatabase layers and digitize into them quickly and easily for subsequent exercises. 

Create a feature data set and within that data set create two feature classes,  1) a polygon feature class for a trees practice area, and 2) a polygon feature class for a landcover practice area. You must digitize your own layers.

Second, copy the NorthCampus_leafoff2017.tif image, found in the repository directory L: drive, under the 4295\CampusImages directory, your VM C:drive. It is large, so it will test your local internet speed, and whether you should plan on working more in the lab.  This will also require you set up a VPN and map the network drive to access the L: drive, as described in the X295 Software Setup document, in part B, above.  You will also find copies on the other cloud repositories, but you should transfer a copy to one of the persistent cloud drives (H: or W:), and from their to the VM C drive, to test your internet speeds.  If it takes too long, then try moving closer to your router, checking your internet settings, connecting with a cat-5 cable, and anything else that will improve your access speed. If it still is too slow, you may decide to install the ArcGIS Pro software on your computer, or to work only in the lab, in person.  See Andy or I if you have issues.

Third, add the MN DNR WMS server (see the resource accordion for week 1 below, for instructions), and load the Ramsey County 2020 images from the MN DNR WMS layer as and image background.  

Fourth,  digitize three (3) boundaries on the St. Paul Campus into the feature layers. You'll only be digitizing the boundaries now
Using the map linked here as a guide, Digitize:

a) a first version of the 5295 Practice Area outline, shown in red on the linked map, into a polygon feature class,  based on the NorthCampus leafoff 2017 image, and

b) change the background image to the 2020 color Ramsey County images from the MN DNR WMS service: https://imageserver.gisdata.mn.gov/cgi-bin/wms?  
The image server is described at the website https://www.mngeo.state.mn.us/chouse/wms/geo_image_server.html

Digitize another copy of the same boundary. Do not display the first boundary you digitized above when digitizing the second, and do not set snapping to snap the second to the existing first boundary. We wish to emphasize the difference in digitizing the same features that one often achieves even under similar conditions. Part of the difference is due to source images, part to human digitizing variation. After you are done digitizing, display the two boundaries together.  Adjust the zoom to inspect closely, noting areas where the differences are largest. 

c) hide/remove the boundary above, and digitize a third boundary from the same image source.  This is just to show digitizing variation within the same person/attempt, even though the source materials are the same. 

Create two maps, exported as PDFswith an image/map background.

In the first map include your first two digitized boundary layers, your name, a title, scale bar, and north arrow, and export as a pdf. Note where you see the largest differences in the boundaries.

In the second map show the second two digitized boundaries, using the same background/image and digitizer.  Include at lease one inset map at a larger scale that shows discrepancies in the two digitizing efforts.

Use the naming/file saving conventions described in the Deadlines section for this week. Note, map creation with the NorthCampus_leafoo2017 image may be slow, if so you can substitute one of the standard ESRI image backgrounds for your maps.

One final note for this week, in this and all assignments and conduct, you're expected to understand and follow the Student Code of Conduct and Academic Integrity. Read it and let the instructors know if you don't understand any parts.

Week 1 Deadlines

Turn in assignments on the Course Canvas Site (link in the introductory paragraphs at the top of this course page), unless specified otherwise. Some activities are due the same week as assigned, but typically they are due the week after their assignment.

Prior to class Next (Week 2) Wednesday, before 10:40 a.m. :

  • Set up access to ArcGIS virtual machines through a browser (much preferred), or install an at-home copy, for ArcGIS Pro, and become familiar with the various cloud drives we'll use this semester.

  • Digitize the polygons as described

  • Turn in the two maps (both to the same canvas bin)

Next Wednesday before class is a hard deadline, you should turn in what you have completed by then. This class moves at a fast pace, and you can't be neglecting new work.  Once the deadline has passed, you will receive a 30% deduction from your graded score, and after two weeks, zero points. Unless noted otherwise, this will be our policy for assignments. If you're traveling out of town for another commitment, pre-clear tardy submissions.

Rules when turning things in:

  • Submit maps as pdfs

  • Submit (future) data as geodatabases (GDB extension), compressed in  .zip or Mac archive formats.  

  • Use this naming convention: include your initials at the start of your files, a descriptive phrase, and a W# where # is the week at the end of the filename.  For example, I might name my map "pvb_practicemap_W1.pdf", my geodatabase "pvb_practice_data_W1.gdb" and my zip file "pvb_practiceareas_W1.zip".

Failure to follow this naming convention for compressed and component files may result in a deduction, and/or a return to you for re-submission. The naming and week identifiers greatly help me organize submissions and grading.

When you turn in geodatabases,  they should not contain copies of layers or extraneous intermediate layers, and the submitted layers should have descriptive names. If it isn't clear to me, I'll ask you to resubmit, and late deductions will apply.

When you turn in vector data layers, make sure you don't have extraneous columns in the tables.  The data may come with "extra" columns, or you may be generating intermediate columns through processing. Keep only those needed for the primary purpose of your data.

Week 1 Resources - slides, videos for Zip/Unzip, Videos for Software Setup, ArcGIS Refresher

Introductory Slides, day one slidesvideo (note this video refers to 2.5 and 5 cm rainfall events, we've changed these to 0.5 and 2.5 cm for this year - ignore the 5 cm reference).

Semester Project "Big Picture" Overview Slides (refer to this throughout the semester), project overview pdf,  video

PDF and video about Software Access
Watch This 1st, a "get started" video;  documents used in video are below: 
Getting Started with Citrix/CFANS Cloud Desktop
Using Citrix/CFANS Cloud Desktop
Using ArcGIS Pro important notes
Screenshots-Login into ArcGIS Pro start Lab

You have to be consistent in moving your work off the VM, due to it's ephemeral nature. All data on the VM disappears into the ether when you log off.

The VM is configured to create a cloud-resident C:, S: and W: drive, and connects to a CFANS L: drive.  The S, W, and L drives are persistent for the semester, so you should copy your data from/to those before closing the VM. Otherwise you'll lose your work.

We will be distributing base data from the S: and W: cloud drives. The same source data will be duplicated on the Skok Lab attached CFANS L: drive. The data for this class are in the ESPM5259 directory. There is ALSO an ESPM5295share directory, where you may create a sub-directory with your name and periodically save a copy of your data.

WHEN YOU FIRST START A VM SESSION, COPY DATA YOU WILL BE WORKING ON FROM THE S: OR W: OR L: DRIVE ONTO THE VM (CLOUD) C: DRIVE

DON'T WORK ON DATA WHILE IT IS ON THE L: OR W: OR S: OR OTHER CLOUD DRIVE - SOONER OR LATER YOU WILL LOSE DATA, PERHAPS CORRUPTING YOUR ENTIRE PROJECT.

Do whatever data creation and analysis on the virtual C: drive. 

When done, BEFOR LOGGING OFF THE VM COMPUTER, COPY DATA YOU WANT TO KEEP FROM THE VM C: ONTO ONE OF THE PERSISTENT CLOUD DRIVES, THE W: OR H: OR S: OR L: DRIVES BEFORE YOU END A VIRTUAL SESSION

 

On a different note, some data sets or project bundles can't be turned in directly, and must be compressed in a package before submitting to Canvas. Here's a video on file compression:
How to Zip/Unzip

Review materials from FRNM3131 (note, data referred to below are in the 3131 course files, but you shouldn't need them for understanding the mechanics):

ArcGIS Pro Refresher295

  • Review this Video, if need be, for starting ArcGIS Pro, creating a new project
  • Here is a pdf excerpt from an intro course lab on creating a Geodatabase, and importing data into it - it is some pretty detailed text, may take a bit to wade through, but it may be a good reference if you've forgotten or didn't learn the startup process
  • Review video here on creating a geodatabase
  • Review video on creating a feature dataset
  • Review video here on digitizing polygons
  • Accessing the MNGeo WMS server in ArcGIS Pro, to specify an image background

 

There is a Personal Zoom Room for Paul and Personal Zoom Room for Andy

Email us if you wish to meet outside of class hours and we'll arrange a time to meet in this room.

Sept. 12, Week 2 - Assignments-Digitizing Review

Week 2 - Digitize trees and buildings

Task 1 - Digitize the tree canopy and buildings for the 5295 Practice Area 

Use the boundaries you digitized last week for the trees and landcover study areas, or look in the L: drive, 5295\Data folder, for the shapefile named "5295DigPract".  Copy the set of files to your working directory (remember, VM C:). 

Use as background the "NorthCampus_leafoff2017" and "NorthCampus_leafon2017"  photos. These source files are on the L: drive, ESPM5295 directory, in the CampusImages folder, and may be mirrored on the S: or H: drives. 

Your goal is to digitize each tree's canopy outline, and each building outline, based on the images. You only have to digitize within the boundary defined by the 5295 practice area.

Manually interpret and digitize the building outlines, placing them into a polygon feature layer.

Manually interpret individual tree crowns based on the various leaf-on and leaf-off images. It is best to use the 2017 images as a base, but you may use others for some areas. You can use leaf-off images to somewhat identify the crowns and to separate evergreen from deciduous trees, but leaf-on images provide the best source for crown edges.

You should do your best job of interpreting the individual trees, even where they grow in clumps. Do not be too meticulous in digitizing tree crowns. Something like 8 to 12 vertices should be acceptable for most normal, "rounded" crown boundaries. The point here is to refresh your digitizing knowledge and practice the skills, not to spend hours digitizing. Use autocomplete digitizing or split polygon digitizing as appropriate on clumps (see resources at right). Remember that individual crowns cannot overlap with other crowns, you must have "planar" topology in this layer.

Also note that the tree crowns can overlap with buildings for this initial data set, but later we will remove the overlap.  It is easiest to digitize crowns rather coarsely where they overlap buildings but don't worry now about matching building edges, or we can use building polygons with the Erase function to remove the overlapping tree portions. There are digitizing options that allow you to auto-complete along existing boundaries, so you could use these match these edges, but it is easier to Erase in this case. 

You should create a text attribute named something like TreeType with the values "conifer" or "deciduous" assigned as appropriate for each polygon.

Add an attribute named "rooftype" to the buildings, and from the images interpret them to be either "flat" or "pitched."

Create a map that includes trees and buildings, and turn in as per the deadline listed in the accordion below.

Week 2 - Deadlines

By next Monday, before the start of class, turn in: 

A pdf map of the tree crowns and building footprints.  Trees should have different colors by type (deciduous or conifer). Also include an image background, your practice area boundaries for the trees and buildings/landcover and the usual map elements (title, name, legend, scalebar, etc.).

Don't be lazy with the legend, each layer/feature type should have a distinct entry, with a descriptive name (no file names like "bldv1), and distinct symbology.

 

Week 2 - Resources, Videos on Digitizing Mechanics, Tools, and Example Reports

Week 2 Slides on digitizing

Video here on using the course data - Do not load files to your ArcGIS map from the L: or S: or W; drive. ALWAYS copy data to the virtual computer (C: desktop is easiest) and then work with the data on the virtual machine local drive. Then copy any new or changed data back to your directory back to the W:, , S:, or L: drive, or to your own computer, or a USB drive or other "permanent" storage. If you load directly from the L or other cloud drives from within ArcGIS you will likely lose data, time, and work.

A video here on managing files/projects/directories in the virtual machine C:  and cloud drives (W:) we're using in this class

Editing, see the intro videos provided in Week 1 on creating a geodatabase and digitizing points and polygons, and these below, excerpted and modified from FNRM3131 for more efficient digitizing:

Your rules specify that the buildings layer must not overlap with trees. You can enforce this with the Erase tool, by first digitizing all the buildings, then erasing the trees with the building footprints. 

See this video and read the documentation on the Erase tool.

Sept. 19, Week 3 - Assignment, Topology, Project Geodatabases

Week 3 - Project Geodatabase Creation, Digitizing, Topology 
Monday Mandatory
Wednesday Optional attendance

Create a Geodatabase with topology for the north campus practice area, containing the layers and topology listed below. Review topology editing/digitizing in ArcGIS pro as needed (videos in this week's resources section). 

Import into your new database the L:\ESPM5295\Data\Week3\5295DigPract shapefile we provide or the geodatabase (it is in NAD83(CORS96/2011) UTM zone 15N coordinates), or import the boundary you created last week, into your new geodatabase.  Also, import the trees and buildings data layers you digitized last week.

When created, your geodatabase should have a feature data set that includes the following feature classes:
1) A "Landcover" polygon layer recording surface cover, with a text column named "material" for the surface type that contains two categories, either 1) impervious (e.g., roads, sidewalks, parking lots, paved plazas) or 2) pervious (grass, flower beds, non-compacted dirt, forested areas, shrubs). 

2) A "Buildings" polygon layer to hold all building footprints for the landcover practice area, with an attribute for the name (text), and roof type (with flat or pitched values).

3) A "Tree Canopy" data layer, imported from last week's digitizing.  Import those data into your geodatabase if you digitized them as a shapefile, or from last week's geodatabase.

4) An Area_Bound layer encompassing your landcover/building "practice" study area - this is imported either from your week 1 digitizing, or the 5295Dig_pract shapefile we provided.

5) Layer topology, with, topological restrictions as:

  • Land Cover and Buildings must not overlap,
  • Land Cover polygons must not have gaps (except the holes created by Buildings) 
  • Trees and buildings must not overlap - remove the tree canopy where it overlaps buildings
  • All layers must be contained within your Study Area Boundary

Digitize Landcover in the 5295 Practice Area. Digitize landcover, with a variable that contains two categories, "pervious," and "impervious."  The landcover layer should have spaces or holes for the building footprints. Create and test the topology rules. Use primarily the North Campus 2017 leaf off and leaf on images for sources, but use other images as needed (e.g., WMS images, other years' campus images, as available)  to locate trees, pervious/impervious features, or building edges as best you can.

Week 3 - Deadlines

By next Monday before the start of class, turn in:

1) Your geodatabase with your completed digitized landcover layer, and your trees and buildings layers from last week, and the completely specified topology rules.

Remember to use our standard naming convention, and zip up your data into an archive.

2) You should also turn in a pdf map that shows your landcover, and your topology with no errors, with the usual other map elements.

Week 3 - Resources, Data Development

Week 3 Slides, Creating an ArcGIS online account, catalog management, digitizing and topology 

Videos on general folder and project data management:

 

Below are  videos on topology to help with the actual mechanics of creating topology and fixing topological errors in ArcGIS: 

-Create topology, 
-Fixing topological errors 

Sept. 26, Week 4 - Assignment, Accuracy Assessment

Week 4 -  GNSS and NSSDA Accuracy Assessment 
Mandatory meeting at 11:40 this Monday (NOTE LATER START TIME), 

Our goal over this week is to assess the accuracy of our primary source image, a 2017 high-resolution leaf-off image in the L drive, \ESPM5295\CampusImages folder. We will identify points for which we have precise and accurate GPS/GNSS data, collected by Andy Jenks. We will then digitize the locations on the images (they will be in slightly different locations than the GPS/GNSS true points, due to small image geometric errors). We will extract the coordinates for both test and true sets, and compare them using a standard NSSDA protocol.

A printable description of the assignment is available for download here

To assess the accuracy of the 2017 leaf-off image, you should:

  • Identify 20 to 25 widely-spaced points on campus for which the truth is available (described in the assignment document, linked above) and identifiable on the 2017 image.
  • Extract the coordinates from the image, most easily by digitizing point features corresponding to the measured GPS/GNSS locations (although the displayed GPS/GNSS points will NOT fall on the true locations on the image), then calculating geometry for x and y coordinates for both the image (test) and GPS/GNSS (true) points
  • Create an NSSDA spreadsheet, using the provided GNSS data as truth, and the image coordinates as test data
  • Create a map showing the image and GNSS layer points

The NSSDA spreadsheet and handbook are downloadable in the Resources accordion, below. If you do not have all points collected and differentially corrected by the deadline, turn in the points and the NSSDA spreadsheet with those points that you have.

Week 4 - Deadlines

Turn in by next Monday, before the start of class

  • NSSDA spreadsheet for your test points,
  • an overview pdf map showing the distribution of your 20 to 25 test points,
  • a map with detailed insets, showing examples of typical errors "zoomed" to five or six chosen test/true pairs.  Zoom in enough to provide significant detail, e.g., so that most of a tactile crossing pad takes up the chip, and so that both your "test" and "true" points are in the chip. This will be larger than the magnification in the example image chips we've provided (we wanted to highlight the location of the points, you want to show the difference in location between true and test points).
  • turn in a zipped geodatabase that contains both your digitized test points and the corresponding true points. These true points should be a subset of the original data we provided, and not just the entire layer.

Week 4 - Resources, NSSDA Accuracy Assessment

Oct. 3, Week 5 - Assignment: Feature Heights from Lidar, Watersheds, Story Maps

Monday Mandatory, Wednesday Optional attendance

Week 5: Calculate feature heights from LiDAR, and create watersheds and Flowlines

I'll be lecturing for an hour or so at 10:40, first on watersheds, then on LiDAR starting at 11:40,  both are Optional.

Create watersheds and flowpaths for our larger study area. A watershed is an area that drains to a point.  A surface path is a route along which water is expected to flow based on topography. 

Creating watersheds was covered in FNRM3131/5131, but many of you will not have taken that course, or it has been a while, so we provide links to instructions. See the videos and pdfs in this week's resources section, to the far right.

Pourpoints and a DEM are in the "Sheds" geodatabase in the class L drive, in the Data directory.  Retrieve this, and calculate the watersheds with the two vector pourpoints as outlets, using the provided DEM. Note that the watersheds go outside the bounds of the previous PracticeAreas polygon, do not clip your results to the North Campus study area, we're transitioning to a larger area. Your output will be vector polygons of the watersheds, and vector flowlines from the flow accumulation layer, with somewhere between a 75 and 300 sq-m threshold for flowlines. 

We provide a figure of the approximate flowchart here. Note that important steps and branches are missing, but you may use this as a starting point. Your watershed boundaries should look approximately like the map linked here.

A note about processing, YOU DON'T NEED TO DO THE DEM FILL STEP WHILE CALCULATING WATERSHEDS in this exercise, the DEM has already been conditioned for you.

The watershed tool sometimes returns incomplete watersheds. The D8 algorithm only allows water to drain to one of eight directions, and in nearly flat terrain you can get divergent flow where you shouldn't. Sometimes this results in a cell near your flow channel with a slightly off direction, creating a second watershed upstream that doesn't drain into your pourpoint. If your watersheds do not match the map linked above, perhaps use a different pourpoint distance, or manually move the pourpoints to be closer to the initial flowlines.

The flowpaths (also called flowlines) might not intersect the provided pourpoints, but only run near.  You should use the SNAP POURPOINT function, with a snap distance of less than 5 meters, for this exercise.  

Create a pdf map of your watersheds, with a suitable image background, flowlines, and the usual legend, north arrow, etc.  

Create a detailed flowchart that describes your specific watershed workflow. This flowchart should include each step, the names of the specific ArcGIS tools you used, and the descriptive names of the output layers.  Any key parameters should also be noted on the flowchart (e.g., snap pour point distance). Export as a pdf, and turn in on Canvas.

Perform the LiDAR height calculation exercise for your project area. You'll use data downloaded from a DNR website for your study area, and process similar data to show feature heights.  

Also pay attention to the recommendation about working with your data on a VM local drive, or you might have long processing times.

Turn a map of your height raster.

Week 5 - Deadlines

Next Monday, before the start of class turn in:

  1. A pdf map of your LiDAR heights raster,
  2. A pdf map of your watersheds, with flowlines,
  3. A flowchart of your watershed delineation process.

Week 5 - Resources: Watershed Creation, Basics of Creating and Editing Story Maps

Watershed Slides

Most of you should have had exposure to the concept of watershed delineation based on a raster DEM.  Here is an excerpt from the "GIS Fundamentals" textbook explaining the general idea, for review: Watershed Background

Below are a video and instructions excerpted from FNRM3131/5131.  The students in that class are provided a "well-behaved" DEM, that has been pre-processed to work. You'll need to substitute your different input files and other parameters, but these provide an example of the workflow in ArcGIS Pro.

Creating watershed instructions, excerpted from 3131/5131, here using the tools:

  • Flow direction
  • Flow accumulation
  • Snap pour points (snap distance less than 5 m)
  • Watersheds

You DON'T NEED TO USE the FILL function on your DEM, included in some of the descriptive materials. The DEM has already been filled for you.  

Video for Watershed Creation

Video for creating vector flowlines from flow accumulation layer. This may require use of the tools

  • Raster Reclassify
  • Raster to polylines

Videos: MnTOPO data download

Oct. 10, Week 6 - Assignments - Model Builder

Monday Mandatory
Wednesday, Optional attendance


Week 6 -   Work Flows and Model Builder
Introduction to Model Builder
This week we'll also redo the watershed delineation exercise, but this time to more explicitly demonstrate the use of Model Builder, a tool for codifying workflows. Model builder perhaps isn't worth the bother for small spatial problems you'll be doing only once, but is useful for complex spatial workflows, and for simpler or complex workflows you'll be repeating with different data sets or parameters.

Look at the example video, the Model Builder Quick Tour, Getting Started, and other resources from ESRI, linked in the right column.

Start a new project, copy in the campus DEM and the pourpoint file you used last week, found in the course L drive, data directory, Sheds.gdb. Build a processing model for watershed delineation using the ArcGIS model builder tool. You basically do the steps you followed for last week's exercise, but write them into a model that can conduct all the steps in sequence.

Your model must start with a DEM and pourpoints, and using these create watersheds and vector flowlines.

You should make the input and output data layers, the snap pourpoint distance, and the threshold area required for a streamline as parameters, entered at run time.

The model saves file paths to data in your project, so you need to turn in your model, project, and your geodatabase.  In theory you can do this by exporting a Project Package, as shown in the video in the resources accordion, below. However, the project package works intermittently, for unknown reasons (even to ESRI). If you have problems creating a package, then save using the alternative, zipping the folder that contains all your project parts, including the model toolbox, data, and project, as described in the "zipping all project files" in the resources column to the far right.

Week 6 - Deadlines

Next Monday, before class,

turn in:

  1. A pdf showing your model builder model, e.g., from a screen grab, or a flowchart, for calculating watershed delineation and streamline creation
     
  2. Your ArcGIS Model Builder model and data for the watersheds/streamlines,

    a) either by zipping the project files (a .gdb, a .tbx, a .aprx, and an index, all within the enclosing directory automatically created by Arc when you start a new project), or

    b) your projected exported as a project package (easier when it works, but it frequently doesn't, so I may then ask for a zipped package as above.)

Week 6 - Resources

Model Builder Introductory Slides.

Slides on Making MB models portable

A simple Model Builder example video

Model Builder resources from ESRI:

-Quick Tour
-Getting Started Building Models
-Model Builder 101
-Model Builder 202 (this is for an earlier Arc version, but much still applies)

If you have time, you can investigate the ESRI Geoprocessing courses, starting here.
Note that you have to sign in through the UMN account, using your X500 name and login, for access.

Finally, since your model builder lives inside a project, and you should turn in both your data and the model.

The preferred way to share your work is by creating something called an export package as shown in the video below, but there is currently a problem as noted above in the assignment:

Exporting a Project Package to submit to Canvas

Unfortunately, it appears this option is now working intermittently, so another option which should work involves zipping the containing folder, including the toolbox files (.tbx), index, geodatabase, and project file, as shown in the video below:

Zipping all project files to submit to Canvas

Oct. 17, Week 7 - Assignment - Project Roadmap, Full Area Data Distribution, Workflows

Mandatory meeting on Monday and Wednesday this week
Week 7
 - 
Project Roadmap, Flowcharting, Project-Wide Data

Monday and Wednesday, we'll discuss the overall project, analysis, and output. 

1) Re-read the project description (linked here, same as provided in week 1 assignments), review the general flowchart, create a detailed flowchart for interception sub-workflow.
Carefully re-read the semester project description provided in the first week, and develop a draft flowchart of your analysis. This will likely be much more complete and refined than what you included in your methods draft. You need to think about the spatial operations and order in which they'll be applied, represented by a box and arrows diagram you'll apply. Come to our meeting on Monday prepared to ask questions about anything that's not clear.

We provide a basic flowchart in the resources column to the right, also embedded within the flowcharting exercise below. We will discuss an example flowchart, and on Wednesday provide a refresher on some analysis tools that you'll likely use to solve our problem. 

This flowchart is missing some details. This week you will provide the details for the canopy interception sub-workflow, a small branch of the overall flowchart, you will expand and add details, and verify your sub-workflow is valid by applying it.  Follow the instructions in the Canopy Interception/Net Rainfall Flowcharting exercise here

2) Get Acquainted and Condition the Project-Wide Data
We've provided campus-wide data very similar to those you have been developing, plus some more. All work from here forward will be using these campus-wide data, and NOT those that you have developed for the North Campus Practice area, earlier.

The data are available on the class L drive, in the Data directory, in the WholeProjectData geodatabase. You will have to modify the data layers a bit for your analysis, e.g., modify or add attributes to change units from cm to meters in the soils data, or add a maximum canopy interception attribute, but these are relatively minor.

Layers and important attributes are:
Soils: Type, a text description of the dominant texture. We provide information on infiltration rates for each of the dominant textures in the project description.
SurfacePermeabilityType, indicating if the landcover surface is permeable or impermeable
TreeCanopy: Type, value Dec indicating deciduous trees, value Con indicating coniferous; CanopyHeig, indicating short or tall trees. You will have to add maximum interception/absorption rates for each height/type combination, as per the project description.
BuildingsRoof, values pitched or FLAT (not green roofs on pitched surfaces)
Project_Study_Area: a bounding area, no attributes of note
Pourpoint2020ppid, numeric identifiers for the watershed outlets 
 

Note that there is not a watersheds layer, nor DEM you will have to import those from the previous labs into your geodatabase.

There are also no rainfall layers, you should create these.

Wednesday - Analysis and Tools
We'll review these tools in class, and describe how we might use them in a workflow to solve your primary analysis:

  • Clip function - for data prep
  • Union (in addition to last week)
  • Dissolve, often used after Union
  • Polygon to raster
  • Raster calculator

Week 7 - Deadlines

Before the start of class on Monday, next week

  • Turn in your flowchart exercise, the first draft of your detailed flowchart, as a pdf.
  • Turn in a net interception map, CInt in the example flowchart.  Note that you must show areas where there are no trees with a value of zero interception.
  • Turn in a net rainfall map, that is, a map of rainfall minus canopy interception, for the 0.5 cm rainfall event. This is the layer labeled RAS that result from applying your sub-workflow in the flowcharting exercise. Display/color it by net rainfall values, in meters, for the extent of the study area.

Week 7 - Resources

Week's slides 

Tool Review slides

Example flowchart graphic (vector analysis, then raster)

Video refreshers on common tools (from FNRM3131)

-Selecting and calculating fields for vector layers
-Clip & Intersect tools
-Dissolve function
-Union note that the union function often creates multipart shapes, so you'll need to do the multi-part to single part to separate them before further analysis
-Multipart to singlepart
-Raster Calculator 

You should use the search function as described in the Finding tools in ArcGIS Pro video and search the online ArcGIS Pro documentation, to understand and then apply the:

- Know about the Polygon to Raster tool, to convert vector features to rasters, prior to using the raster calculator

Oct. 24, Week 8 - Assignment - Net Rainfall in Model Builder, and Manually Calculate Maximum Surface Absorption

Week 8 - Basic Calculations, net rainfall layer as Model Builder model, and do the manual workflow to create the maximum surface absorption layer

Monday mandatory meeting

1) Net Rainfall in Model Builder: This week you will Create a Model Builder model that calculates net rainfall. You will eventually apply this model for both your 0.5 cm and 2.5 cm rainfall events, so consider specifying the rainfall amount as a parameter. Your model runs the sub-workflow you performed last week. Rainfall and tree canopy layers are your inputs, and the net rainfall (RAI) layer is your output. You do not have to specify as parameters the rainfall amount layer and tree canopy layer, but if you do, it will make your work easier in the future. Verify you are getting correct results by visually inspecting inputs and outputs, and comparing manual workflow values from last week to those you get in your model output.

Export and turn in a Project Packet (see the video in week 6 resources column if need be) that contains your model and just your input and output data layers (don't include your other data layers in the gdb in the packet, just include the rainfall and canopy inputs, and the results, along with the model). If the project packet utility isn't working for you, then as described earlier you may turn in a compessed project enclosing folder, with toolboxes, the aprx project file, your .gdb,  and the index directory, as described earlier.

2) Surface absorption layer: Create a manual workflow that calculates maximum surface absorption, and create a flowchart of your process that combines the landcover, buildings, and soils layer to create this maximum surface absorption layer. This layer will have a value of zero for the impervious landcovers (roads, sidewalks) and a zero for buildings, and the maximum soil infiltration layer for the remaining locations. 

Turn in a pdf map of the maximum infiltration layer, colored by maximum absorption/infiltration categories, expressed in meters. Remember to include a legend, title, north arrow, and scales.

3) turn in a flowchart of your sub-workflow to calculate maximum absorption/infiltration

Week 8 - Deadlines

By next Monday, before class, turn in:

  1. Project Packet of your net rainfall sub-workflow in Model Builder,  
  2. Map of the maximum surface absorption layer you created that shows infiltration across the study area, colored by meters absorption, with the usual title, legend, scale bar, and other map elements.
  3. Flowchart of your detailed maximum infiltration workflow, as a pdf.

Week 8 - Resources

Week's slides:  Calculate Maximum Infiltration Layer Manually, and Net Rainfall in Model Builder 

Videos:

Video here on making your models portable across projects. ArcGIS Pro 3 changed from 2.x, so this is a bit of an update/addition to the previous videos/instructions on making models portable

Long(ish) video here with a general hint at how to structure your geodatabases for easier debugging in Model Builder (MB), and I walk through a MB model that roughly follows the earlier provided general flowchart.

Video here on stepping through a MB model, running a single tool at a time.

You may assign individual canopy interception based on canopy height and type, via selecting table records based on values, manually, or in Model Builder 

An example video of using a code block to shorten the number of steps calculate a field value for a feature, based on other column values for that feature. 

Another brief example on else-if python code block, an alternative to multi-step selection, but more complicated

Oct. 31, Week 9 - Assignment - Model Builder Model for Net Surface Absorption, and Workflow to Calculate Net Runoff for 0.5 cm

Week 9 - 1) Model Builder to calculate maximum surface absorption, 2) Calculating Net Runoff for 0.5 cm Rainfall (remember, some of the videos reference 2.5 cm rainfall events, we are doing 0.5 here through all steps to net runoff, and 2.5 later in the semester)

Mandatory meeting Monday, optional Wednesday

This week we introduce a few more tools, and provide more practice with Model Builder.  The idea is to stitch together model branches in a way that will help you when you have to do your base case calculations, and especially for the mitigation calculations. You should identify the inputs for your models, and may want to specify as parameters those that you will be changing with each mitigation run. This will allow you to run the model(s) in a more automated fashion to streamline your work.

In addition, we'll introduce the tools that help you automate manual operations in your workflow, so that you can incorporate them into model builder, and also cover the perhaps new tools that let you aggregate across the net runoff layer, giving you the final data for your tables. Our target is to combine the three branches of analysis you've already conducted - net rainfall (after interception), maximum surface absorption, and watersheds.  You don't have to combine all three, you run them separately, and then run a fourth model that uses the outputs of each of the branches as an input for the final combination that calculates your output.

You should apply the combined workflow, using a combination of the model builder models you've created and manual tool application,  and calculate a net runoff layer covering your two watersheds, based on current surface conditions and a 0.5 cm storm.

The work above will be with tools you already know, but we will introduce a few new tools, needed to aggregate over the watersheds, so that you may sum volumes (cubic meters) of water for each watershed:

  • Zonal statistics for Raster
  • Summary Statistics for Vector

 You will apply one or more of these to your net runoff layer to aggregate water volumes by watershed

Week 9 - Deadlines

By next Monday, before class, turn in :

  1. Project Package showing your maximum surface absorption model, with needed input data (only, no intermediate data),
  2. A map of net surface runoff, either for the entire campus, or subset for the study watersheds, with a 0.5 cm rainfall
  3. A spreadsheet with a row for each watershed, with columns of your average interception in cm, average infiltration in cm, and summed aggregate runoff, in cubic meters, for each of the target watersheds.

Week 9 - Resources

Week's slides, Reclassification and Summarize by Zones to table, here

Example here on how to summarize or calculate other zonal statistics across a  layer to a table.

2nd example here of how to summarize across a vector polygon layer/table.

Short video on a strategy to use when MB doesn't display an input file in a subsequent tool in a workflow 

Nov.7, Week 10 - Assignments - Integrate Model, and Calculate Runoff for 0.5 and 2.5 cm Rainfall

Week 10 -  Integrate all three branches of your complete model,  calculate runoff for 0.5 and 2.5 cm rainfall. 

Stitch together your three model branches (net rainfall, surface absorption/infiltration, and watersheds) in one combined model. Apply this combined model to estimate runoff for the 0.5 cm rainfall event to check against the results when you did each branch manually.  When your model is working, apply it with a 2.5 cm rainfall input.

This repeats what you've done in pieces before, but the goal is to integrate it into a single model. Test at the manually calculated 0.5 cm rainfall level, and calculate key outputs at the 2.5 cm rainfall.

Sometimes a Frankenmodel doesn't work, and is extremely time-consuming to debug, so first try to create a combined model.  After a decent effort to debug, is o.k. if you run your main branches to create intermediate data, and then create another model that combines this intermediate data. 

Turn in a Project Package that contains your combined model and input data.

Week 10 - Deadlines

By next Monday, turn in: 

1) A pdf graphic of your combined model,  

2) pdf maps for the 2.5 cm rainfall of a) net rainfall, b) surface absorption, and c) net runoff

3) A spreadsheet with a row for each watershed, with columns of your average interception in cm, average infiltration in cm, and summed aggregate runoff, in cubic meters, for each of the target watersheds.

4) Model builder model of your three analysis branches, stitched together into one model, within a project package

Week 10 - Resources

No new resources

Nov. 14, Week 11 - Assignments - Mitigation Strategies

Monday Mandatory
Wednesday Optional attendance


Week 11 -  Discuss and implement strategies for mitigation, create "new" forest canopy

We will now start mitigating runoff, reducing it to zero for the two outlets. 

There are five primary ways we'll use to mitigate runoff: increase forest canopies, add rain gardens, convert impervious to pervious surfaces, add green roofs, and add underground storage. You should start work on creating new canopy and rain gardens for the 0.5 cm rainfall this week and next, and perhaps pervious pavement, depending on the strategy you choose. You don't have to complete your 0.5 cm mitigation until after Thanksgiving, but it is due the Wednesday after we get back, so you should get most of the work done before and perhaps start on the 2.5 cm mitigations. 

This week we will start by adding forest canopy and rain gardens with a goal of reducing runoff from a 0.5 cm storm event to within 5% of zero for each watershed.

We will discuss general strategies for adding mitigations, and walk through one workflow for canopy addition. You only have to turn in the new canopy layer, you do not have to calculate mitigated runoff this week, but you may have to do several runs through your workflow with additional mitigations, so you should do at least one preliminary run to calculate runoff after your first mitigations.

Your specific assignment for this week is to:

1) Create a new forest canopy layer, and a model builder model for adding canopy to your existing layer. Assume the input to the new canopy model is a set of points, with the type of tree in an attribute for that point. Starting with points as input (you'll have to manually digitize these) your process will buffer, erase by buildings (canopy can't overlap buildings), clip/union with the original trees layer, and perhaps other steps to create a modified canopy layer.  This layer will be part of your 0.5 cm mitigation recommendations; you will use this new layer in your frankenmodel to calculate runoff after mitigation.

Create a model builder model that takes the existing canopy and a set of points as input, and creates a new layer with added canopy that is compatible with your frankenmodel.  Export an image or pdf of the model builder graphic/flowchart of your canopy model  and turn that in.  You don't have to turn in a project package for the model.

You need to calculate costs for the new canopy, and you have to pay for the total new canopy planted, even if it overlaps with the existing canopy. Hence your cost is based on the total new canopy area from your buffering, before you union it with existing canopy. There are tradeoffs between the two tall canopy types, conifers absorb more water for the area they cover, but they have a smaller maximum diameter, so they reach out shorter distances and hence may leave more impervious surface in large parking lots uncovered.  You can plant trees in parking lots, but only in existing "islands" in the lot, that is, raised curb areas within the lot that are currently pervious

Create a png image or a pdf map that shows the combined canopy layer (old and new), highlighting what you added/changed compared to the old layer (you can do this by displaying the new layer on top of the old combined layer, using different shades). Include text listing the original canopy area, the new canopy area, and the new canopy cost, by watershed, somewhere on the map.

A few observations:

Hold off on a model run until you've both added canopy and added a rain garden. Your first new run at a minimum should include both new trees and one rain garden in each watershed. This will give you a better idea of whether your rain gardens are large enough, and an estimate of watershed outflow below the rain garden. You don't want to do any more runs than you have to, and with a little bit of pre-calculation, you can avoid many iterations.


Do canopy first, rain gardens second, and (if you think you need it) pervious pavement last. Tall trees of both types absorb all the 0.5 cm rainfall at the lowest cost per unit area, so it makes sense to add canopy first.

You must decide between conifers and deciduous trees. Deciduous trees have a larger diameter, so they may reach farther across roads. Both types absorb all of a 0.5 cm storm, but the conifers absorb more, so if you use the same canopy layer for your 2.5 cm mitigations, tall coniferous trees may be preferred.  Don't worry too much about optimizing, perhaps when placing trees near the edge of an impervious area, consider the size of the impervious area when determining tree type. Or just plant all one type, and use other methods to mitigate the remaining runoff. 

 

2) Adding rain gardens. Since trees won't mitigate rainfall that falls on buildings and trees won't cover all other impervious surfaces, you might think it wise to convert some of the buildings to green roofs or add impervous surfaces now.  But both impervious surfaces and green roofs are much more expensive per unit of water stored, particularly for a 0.5 cm storm - so you are substantially raising costs unnecessarily. A better option is to estimate the runoff from all building roofs in each watershed before your first 0.5 cm rainfall run, and place a rain garden near the outlet that will capture all that runoff, adding perhaps a little more for uncovered impervious surface.

There are two complications with rain gardens.  First, they need to be near flowlines (see problem description from first week for distance limits). Second, they are limited to a 0.5 meter depth, so you need to make sure you don't over or under size them, and give them too much or too little credit for water mitigation. If you make the rain garden too big relative to the area upstream, it won't fill up for the 0.5 cm storm, and so will have wasted money making it too large.  If it is too small, it won't absorb all the upstream water.

You will need to add at least one rain garden in each watershed. Rain gardens should be placed downstream from all buildings and large impervious areas that aren't under trees.  You should examine and place rain gardens, starting with large flat grassy areas, parking lots, and plazas, likely placed as near the watershed pourpoint/outlet as possible, perhaps adding additional rain gardens on side branches if the need is too large on the main branch for the available space. 

For now you just have to place and approximately size the rain garden, that is, put in the two layers that represent the rain garden - a pourpoint that defines where water enters the rain garden and hence the upstream area, and a polygon that represents the rain garden.  We assume all water flows into the rain garden, and if more water enters than the rain garden capacity, excess water flows through back into the water course.  Most rain gardens are effectively operating this way, with either surface or sub-surface connections to the "watershed" flowlines, which you don't have to show.

One approach on sizing rain gardens is to estimate runoff based on your previous runs. You have the runoff calculation without new canopy. You have the new canopy area. You can calculate the approximate extra interception from the added canopy, visually adjust for canopy over areas with no runoff, and calculate a target rain garden size. You set the rain garden area to match your expected water volumes from the amount of runoff the "extra" canopy didn't catch.   Make a rain garden large enough to capture that amount.

An alternative to approximately sizing your rain garden before doing a full run is to use the roof area in the watershed to calculate roof runoff volume, and make your rain garden at least large enough to capture that amount.  The rain garden is 0.5 meters deep, so the rain garden area will be about 1/100th the roof area to capture roof runoff for a 0.5 cm storm, 0.5/50 = 1/100. You may want to up the rain garden size from that to capture water from impervious features that you can't cover with new canopy. You can then do a full runoff calculation through your models, calculate the amount of runoff you don't capture, or the "extra,"  and adjust the size of the rain garden capacity if it is very much too large or too small.  You may have to do a few runs to mitigate the remaining runoff from a 0.5 cm storms with added canopy and rain gardens.  Put in sufficient mitigations measures so that you remove 95% of the runoff for our target 0.5 cm storm. You need to document areas and costs for your mitigation measures, as described in the deadlines section.

The full mitigation for 0.5 cm is due Wednesday, the week after Thanksgiving

Continuing Work, Coming Weeks
Your work in the remainder of the semester will be to change the input data to reflect new mitigation measures for the 2.5 cm rainfall level (e.g., perhaps more canopy, changing pervious pavement to impervious pavement, adding more rain gardens, green roofs, etc.).  You then run your complete runoff workflow from the start, with changed inputs to calculate new runoff, and add/reduce mitigations accordingly until runoff is zero for both storm sizes.  

You must calculate costs for your mitigations.

Some of you may opt to add impervious surface for your 0.5 cm rainfall level. Impervious to pervious conversion is most efficient when done on the soils with the highest maximum infiltration rates. To represent this conversion from impervious to pervious, make of copy of your original impervious surface, and split new polygons from existing features  (e.g., roads, sidewalks, plazas) and give them pervious codes in your data layers, and then do new runs. You will have to calculate the costs of impervious to pervious conversion, by first calculating added area, then multiplying by the cost per area charge.  If you do convert impervious surface for this week's work, include it on the same map as with the rain gardens, and the area and cost information somewhere on the map. If you do add impervious areas, you should turn in an additional map that shows the new pervious surface as well as listing areas and cost.  Submit it with your raingarden layer on Canvas.

In the coming weeks with 2.5 cm rainfall you'll have to perhaps add more canopy, add impervious surface, enlarge and add new rain gardens, and add green roofs and perhaps underground storage for the 2.5 cm rainfall. You can use your runoff from the 2.5 cm baseline conditions to give you the target volume to mitigate.

 

Week 11 - Deadlines

Before class on Monday next week, turn in:

1) A flowchart/screen grab of the model builder model for the process you used to create new canopy, 
2) A pdf or image/png map showing your old and new canopy layers towards mitigation of a 0.5 cm rainfall event; it is easiest if you format it such that it can easily be incorporated into your reporting medium, e.g., a story map, slide deck, or report, so create font sizes appropriately.  Also include the area and cost of new canopy on the map,
3) A similar map for rain gardens, with both the new pour points and rain garden polygons, and with the rain garden area, capacity, and cost.

Week 11 - Resources

Week's Slides, Buffering and strategies for "Creating" new canopy, and calculating rainfall mitigation needs.

Video here of one workflow and MB model to add tree canopy

Document describing strategies and examples for mitigation planning

Nov. 24, Week 12 - Assignment

Week 12 - Thanksgiving, and continue mitigations

Week 12 - Deadlines

Turn in the Wednesday after Thanksgiving, before Class: 

1) a map of converted pavement, from impervious to pervious, overlain by the flowpath vectors, an outline watershed layer, and with an image background.

2) a map of rain gardens (if needed), to mitigate runoff for 0.5 cm, overlain by the flowpath vectors, a hollow fill watershed layer, and with an image or map background,

You don't need to calculate areas, costs, or other attributes, I just want to see some progress on this mitigation work. 

Week 12 - Resources

Week's slides here

Video on strategies for converting impervious surfaces to pervious surfaces

Converting impervious surfaces to pervious surfaces will likely require splitting polygons, often splitting pieces and then merging, covered in general videos here:

Remember to assign new table values reflecting the switch from impervious to pervious surfaces.

Video on strategies for adding rain gardens, balancing capacity to runoff, and downstream accumulation of overflow from upstream rain gardens.

Nov. 28, Week 13 - Assignments

Optional attendance both Monday and Wednesday

Week 13 -  Finalize rain gardens and impervious surface mitigations for 0.5 cm storm
Optional attendance both days

Week 13 - Deadlines

Turn in by Monday, next week, before class, at the start of class:

1) map showing the rain gardens, with flowlines and watershed boundaries (not filled), and an image background. Each rain garden should have an identifier, a number or name, and be labeled on the map. This identifier will correspond to an entry in a table, submitted separately below, showing the surface area of the rain garden in sq. m., the volume of water stored for each rain garden in cubic m., the amount of runoff from the watershed upstream for a 2.5cm storm,  and the cost of the rain garden.

2) A table corresponding to the raingarden layer, with a row for each rain garden, and the following columns for each row:

  • rain garden identifier (number or name),
  • the surface area of the rain garden in sq. m.,
  • the maximum volume of water stored for each rain garden in cubic m.,
  • the amount of runoff from the watershed upstream of the rain garden, for a 2.5cm storm, 
  • and the cost of the rain garden.

3) a map showing new pervious surfaces, with watershed boundaries (not filled) and an image background, and an annotation showing the total pervious surface area added, and the total cost.

 


 

Week 13 - Resources

Video, calculating summed area and cost of green roofs

Video, workflow calculating rain garden costs, converted pervious surface areas and costs.

Video, briefest of introductions to Story Maps, an option for your final report.

Dec. 5, Week 14 - Assignments

Optional attendance Monday and Wednesday

Week 14: Finish calculations for 0.5 cm storm, "Adding" Underground Storage,  and Start Model Runs and mitigations for 2.5 cm rainfall. 

Modify rain gardens, canopy, and impervious surface to drive runoff to zero for a 0.5 cm storm. Create tables as defined  in the project description that show the amount and cost of each of these mitigations (see resources accordian for this week). Create pdf of these tables, and turn in.

Beginning with your existing mitigations, incease impervious surface, rain gardens, or canopy, or add Green Roofs towards mitigating a 2.5 cm rainfall event. You may still have positive runoff after adding rain gardens and pervious surface, most commonly in the sub-watershed below your most downstream raingarden. You may need to increase pervious surface somewhat, or modify/add additional rain gardens.  Do this to drive if there isn't sufficient left to reduce runoff to zero, you may need to add green roofs.  Any flat roof can be converted to a green roof, they will absorb all the rainfall of a 2.5 cm storm, (and any amount of rain up to the capacity of a green roof, up to 5 cm for our project).  Green roofs are an expensive way to reduce runoff, and is limited to just the roofs, but is a less expensive alternative than underground storage. 

The amount of runoff reduction for a 2.5 cm storm for a green roof is easy to estimate - the area of the roof in square meters, multiplied by 2.5 cm (or 0.025 meters), for cubic meters of outflow reduction.  If the entire building roof is within a watershed, you don't need to do another full application of your geoprocessing workflow, because of our assumptions of no absorption of overland flow. You can calculate the rainfall volume that falls on any converted roof, and subtract that amount from the runoff calculated with your rain gardens and pervious surface present. However, some of your converted buildings will likely be split across watersheds, either the two main ones, or your raingarden sub-watersheds, so you likely can't use a manual approach.  What to do?

You can use the approximate building area and rainfall amount in a watershed to estimate how much water you can remove through green roofs. If the total amount of excess water is less then the maximum amount of green roof, then convert only the needed portion of the roofs to green roofs by editing the attribute table for building roof type, and re-run your model.  If the amount of water you need to mitigate is larger than that which falls on roofs, then convert all your flat roofs to green roofs, and re-run the model.

You must calculate the cost, on a per surface area basis for converted rooftops.


After subtracting the reduction in runoff due to green roofs, you may still have a small a positive outflow after 2.5 cm storm. If that is the case, then you can simply designate an amount of underground storage.  Again, you don't need to re-run your workflow, you can simple designate the amount of underground storage as that leftover after everything else, and calculate your amount of underground storage required, and build the appropriate table.

The table should include the total mitigation costs for each type of mitigation. Besides the column/row labels, there will be two columns, one for each watershed, and the following rows, with all areas in square meters, all costs in dollars:

  • Added canopy area,
  • Canopy cost,
  • Impervious to pervious conversion area,
  • Surface conversion costs,
  • Total area rain garden,
  • Rain garden cost,
  • Green roof area,
  • Green roof cost,
  • Underground storage volume,
  • Underground storage cost
  • Total Cost, all mitigations


You then run your models, you have to account for the larger inflow to your rain gardens, and manually adjust for the outflow. Many of them will likely not have the capacity for a 2.5 cm storm, so you will have to add back the overflow to your downstream amount.

You can then calculate the additional added underground storage required for the excess runoff. 

You will create a table for this run, similar to the 0.5 cm run. You do not need to complete this work this week, but will next week.

Week 14 - Deadlines

Next Monday, by 10:40 am, turn in

1) a map of mitigations you've designated to date for a 2.5 cm storm, showing all added canopy, impervious to pervious surface conversion, all rain gardens, and buildings colored by roof type (green or not).

Week 14 - Resources

None

Dec. 12, Week 15 - Finish Model Runs, 2.5 cm Rainfall

Week 15: Finish model run for the entire area to mitigate a 2.5 cm storm

Create a new table for the 2.5 cm storm with a column for each watershed, that includes the following rows (same as above, areas in square meters, costs in dollars):

  • Added canopy area (this will likely be the same as your previous 0.5 cm table, unless you optionally changed it)
  • Added canopy cost (same as 0.5 cm table if you didn't modify canopy)
  • Total Impervious surface conversion area,
  • Total Impervious surface conversion costs,
  • Rain garden area (this may be the same as your 0.5 cm table, depending on additions)
  • Rain garden cost (this may same as 0.5 cm table)
  • Green roof area,
  • Green roof cost,
  • Underground storage volume (cubic meters),
  • Underground storage cost
  • Total Cost, all mitigations

By the end of the semester (Dec 22), you should turn in four things, three geodatases and a final report

You should put your final geodatabases on the L:drive, in the 5294 share directory, in a directory with your name and the word "final" as part of the directory name. You should also submit a note to the class Canvas site for the final data, letting me know you have transferred the data to the L drive.

You should turn in your final report on the class Canvas site, in the final report section.

1) A geodatabase with the word "Current" in the name that contains data used for calculating your "current condition" runoff for all required rainfall amounts. These are the base final data, as provided, with any modifications to the main data layers.  The geodatabase should also include your final "surplus water" layer, that is, the layer that you summed by watershed to get the total runoff volume for the study areas. 

2) A geodatabase with the modifications for the 0.5cm storm mount in the name, e.g., "p5cm", that has your initials in the name, and that includes the modified layers used to obtain your corresponding mitigation of runoff. You should include only the modified layers the storm level only, e.g., the canopy layer with added trees for a 0.5 storm, the impervious/pervious surface for the storm level, etc.  You should NOT include the original canopy layer, original impervous surface layers, or the buildings without green roofs, etc., you should only include modified layers used in the 0.5 cm storm calculations.  If you did not need to modify a layer to reach the 0.5 cm threshold (e.g., no green roofs required for buildings), then just include the original layer (e.g., the original buildings).

3) A geodatabase as in 2, above, but for the 2.5 cm rainfall level.

4) Your final report. Your final report can take one of several forms, depending on your interest. It could be a short written/graphic report, a presentation with figures and interspersed "dense text" slides, with more detailed than normal descriptions, or something online, e.g., an Arc Story Map. The form you choose should include a brief description of the goals and study areas, and focus on where the primary runoff generation areas were, and a description/discussion of the changes for reducing runoff to zero under the different rainfall amounts. This should include appropriate maps/figures.  

If you create your report as a website or story map, you only need to turn in a pdf or document with a URL to the report site.

Different report format may be used, but should be agreed upon individually with the instructor.

Week 15 Deadlines

Next Monday, by 10:40 am, turn in

1) The required table of results for a 2.5 cm storm

2) a map of surface runoff under a 2.5 cm storm, with watershed outlines, flowpaths, and buildings, symbolized by roof type (green or not).

Finals Week, Assignment

Finals Week: No class final; all assignments due by Wednesday, December 23, 1:30 pm

You should turn in four things, three geodatabases and a final "report".

You should put your final geodatabases on the L:drive, in the 5294 share directory, in a directory with your name and the word "final" as part of the directory name. You should also submit a note to the class Canvas site for the final data, letting me know you have transferred the data to the L drive.

You should turn in your final report on the class Canvas site, in the final report section.

1) A geodatabase with the word "Current" in the name that contains data used for calculating your "current condition" runoff for all required rainfall amounts. These are the base final data, as provided, with any modifications to the main data layers.  The geodatabase should also include your final "surplus water" layer, that is, the layer that you summed by watershed to get the total runoff volume for the study areas. 

2) A geodatabase with the modifications for the 0.5cm storm mount in the name, e.g., "p5cm", that has your initials in the name, and that includes the modified layers used to obtain your corresponding mitigation of runoff. You should include only the modified layers the storm level only, e.g., the canopy layer with added trees for a 0.5 storm, the impervious/pervious surface for the storm level, etc.  You should NOT include the original canopy layer, original impervous surface layers, or the buildings without green roofs, etc., you should only include modified layers used in the 0.5 cm storm calculations.  If you did not need to modify a layer to reach the 0.5 cm threshold (e.g., no green roofs required for buildings), then just include the original layer (e.g., the original buildings).
 

3) A geodatabase as in 2, above, but for the 2.5 cm rainfall level.

4) Your final report. Your final report can take one of several forms, depending on your interest. It could be a short written/graphic report, a presentation with figures and interspersed "dense text" slides, with more detailed than normal descriptions, or something online, e.g., an Arc Story Map. The form you choose should include a brief description of the goals and study areas, and focus on where the primary runoff generation areas were, and a description/discussion of the changes for reducing runoff to zero under the different rainfall amounts. This should include appropriate maps/figures.  

If you create your report as a website or story map, you only need to turn in a pdf or document with a URL to the report site.

Different report format may be used, but should be agreed upon individually with the instructor.

Finals Week - Deadlines

Due by _____

Your final geodatabases should be loaded on the class L drive, in the 5295share subdirectory, in a directory you create with your name and finalproject in the title, e.g., PBolstadFinalProject.

Turn in your final report or a link to it via the class canvas site.

Please fill out the online course evaluation here