Illinois NRCS GIS Tools V.2.0 User Guidev.2.0 - 3/2017 Page 5 2. File Structure and Data Management The file structure and names are important to understand before utilizing the GIS

Illinois NRCS GIS Tools v.2.0

User’s Guide

v.2.0 - 3/2017 Page 2

Table of Contents

A. TOOL SETUP ............................................................................................................................................................... 3

1. ArcMap Setup Procedure ........................................................................................................................................ 3

2. File Structure and Data Management ................................................................................................................... 5

B. USING THE TOOLBOX ................................................................................................................................................. 6

1. Create Contours, Depth Grid, Hillshade, DEM Tool.......................................................................................... 6

2. Create Contours By AOI Tool ................................................................................................................................. 7

3. Avg. Slope by AOI Tool ............................................................................................................................................ 8

4. Slope Raster by AOI (Percent) ............................................................................................................................. 10

5. Clip/Merge Adjacent DEMs/DTMs ........................................................................................................................ 12

6. Soil Data Request (ONLINE ONLY) ..................................................................................................................... 13

7. Troubleshooting ....................................................................................................................................................... 17

C. BACKGROUND ............................................................................................................................................................ 19

1. LiDAR Map Products ........................................................................................................................................... 19

2. General ArcMap Procedures for use with Tool ............................................................................................ 20

3. Changing Layer Symbology .............................................................................................................................. 26

Illinois NRCS GIS Tools v.2.0

The NRCS GIS Tools toolbox contains tools to create map products from LiDAR derived data or any Digital Elevation Model (DEM). User errors can produce unexpected results; proper care should be taken to review the map products generated and to assure their intended accuracy. Refer to the current Illinois NRCS LiDAR Policy to review the acceptable use of LiDAR derived data for engineering practices. This User Guide was written to work with Esri ArcGIS ArcMap 10.3. March 2017 Jarin Rudsell, Agricultural Engineer, Milan, IL Sarah Anderson, Assistant State Conservation Engineer, Champaign, IL Andrew Fulton, Acting Assistant State Conservation Engineer, Champaign, IL

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A. TOOL SETUP 1. ArcMap Setup Procedure

The following steps will need to be completed only once per computer station setup unless the station is updated or file paths for the tool folder are changed.

a. Enable Spatial Analyst Extension

The Spatial Analyst Extension needs to be added for the NRCS GIS Toolbox to function properly.

To enable the Spatial Analyst Extension select Customize → Extensions…

Make sure the box next to Spatial Analyst is checked and click Close.

b. Add the ArcToolbox Window

To activate the ArcToolbox Window:

Select the ArcToolbox Window Button on the Standard Toolbar

Or…

Select Geoprocessing → ArcToolbox

The ArcToolbox Window can be docked if desired by left-clicking and hold on the Window Title Bar (blue bar at top of ArcToolbox). While holding the mouse button down, slightly move the mouse to activate the docking function: some blue arrows will appear in the window. Then, move the mouse cursor to the blue arrow where you want to dock the box, and let go (unclick) the mouse button. The ArcToolbox should be visible for each future session of ArcMap unless the user closes the box.

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c. Add NRCS GIS Tools Toolbox and Make it a Default Toolbox

Save the NRCS_GIS_Tools folder to a location on your Desktop or C: Drive. This folder should be placed in a location that will not change. (If this folder is placed on an external drive that can have a drive path that changes, ArcMap will not be able to find it and you might have to reload the NRCS GIS Toolbox each session.) Copy the folder to the location in its entirety; the tool references other files within the folder so the toolbox cannot be separated from the support folder and still function properly.

In the ArcToolbox Window Right-Click on ArcToolbox and select Add Toolbox…

Navigate to and open the NRCS_GIS_Tools folder and Select NRCS GIS Tools.tbx

(Don’t Double-Click into the Toolbox, just select it) Then click Open; The Toolbox will be added to the top of the ArcToolbox Window.

To add the NRCS GIS Toolbox to the default toolbox list in ArcMap, Right-click on ArcToolbox in the ArcToolbox Window and select Save Settings → To Default

If for some reason the NRCS GIS Tools Toolbox does not load when a map document is opened right-click on ArcToolbox in the ArcToolbox Window and select Load Settings → From Default.

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2. File Structure and Data Management

The file structure and names are important to understand before utilizing the GIS toolbox. The toolbox requires the user to select a workspace to store data produced from the tools in the toolbox. A workspace is just a GIS term for a folder in Windows. The workspace path must not contain any spaces or special characters. RECOMMENDATION: Prepare a workspace path on an external hard drive or in C: drive to eliminate issues with data storage on local drives and invalid workspace characters. Please note that the file path to My Documents will NOT work for the workspace (because “user.name.My Documents” has a space and period in the file path name). The GIS toolbox contains five tools in the current version. Each of these tools establishes a separate subfolder in the workspace. The folder example to the right shows what the GIS toolbox does in the workspace that is selected by the user each time a tool is run. In this example, the workspace selected was Run1. If there is not an existing .gdb folder, each tool will create one. In the example, the tool-created folders are Run1_1CreateAll.gdb, Run1_2CreateContours.gdb, Run1_3AvgSlope.gdb, Run1_4SlopeRast.gdb, and Run1_5MergeDEM.gdb. Each subfolder in the workspace is particular to one of the tools in the toolbox. If the user runs the same tool twice, the tool will overwrite data from the previous run if the same workspace folder is selected. To run the same tool a second time while maintaining the output from the first run, create a second workspace folder so the data from the first run is not overwritten: for example, create a workspace folder Run2 for the second run. The GIS tool can create large files that can create storage issues. There is no need to save the tool’s output layers for extended periods because the data can easily be recreated. RECOMMENDATION: Delete the tool-created folders periodically, especially when the tool will be run in various coordinate systems. When the tool overwrites data in the workspace folder, not all files are removed. If the previous run was in a different coordinate system, the leftover data may cause erroneous results in the second run. If the tool will be run using Digital Elevation Model (DEM) or Digital Terrain Model (DTM) data with a different coordinate system than was used for previous runs, using the same workspace folder, then the tool-created folders in the workspace should be deleted prior to running the tool in the second coordinate system. If the user wants to run the tool twice in two separate coordinate systems and still maintain the data from the first run, select a second workspace folder (Run2 in example above).

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B. USING THE TOOLBOX NOTE: In this section, Using the Toolbox, the Area of Interest (AOI) is defined as the geospatial extent for which the tool produces data products (layers). So for example, if you are running the tool to create contours that you will later use to draw a drainage area, ensure your AOI is larger than the estimated drainage area.

1. Create Contours, Depth Grid, Hillshade, DEM Tool

Tool Products (layers created):

Contours -- User can create contours on 2, 5, 10, or 20 ft intervals. Contours will be in units of feet as long

as the inputs are correct.

Depth Grid – This layer will show locations where water could become ponded. It is based on topography

only, and does not take into account seepage into the soil or site specific drainage features. This layer can be

useful when determining where a culvert is likely to exist, show small berms that otherwise may be difficult to

locate by showing water backing up behind the berm.

Hillshade – The hillshade is created with a default transparency of 50%. This hillshade layer is an image that

can be used with both the produced DEM as well as with an aerial map overlay.

DEM – The DEM produced with a color ramp to accentuate elevation difference. The colors are not tied to

specific elevations and will change as the data frame zoom changes. It is helpful to view this product along with

the created hillshade layer.

Steps to Run Tool: See Section C.2.a. Adding LiDAR Derived Data for instructions on how to add the DEM or DTM data if needed. Add the DEM or DTM as a layer to the ArcMap project prior to running the tool. In the ArcToolbox window expand NRCS GIS Tools V1.1.2 → Field Office Tools → and double-click the 1.Create Contours, Depth Grid, Hillshade, DEM tool Browse to and Select Workspace:

This is the location where the GIS product data will be stored. (Reference A.2. File Structure and Data Management.) The file path cannot contain any spaces or special characters. Use the “navigate to folder” button to navigate to and select a workspace. (Note: Just select/highlight the folder to use as a workspace and click Add. Don’t double click and navigate inside the workspace folder.) Input DEM: Use the dropdown to select the DEM or DTM for the county. Do NOT use the DSM file.

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Add Features Interactively (Option 1): Select the drop down menu to the left of the Go To Folder icon. Select DefineAOI2::Enter_your_Area_of_Interest if the Area of Interest (AOI) will be drawn manually. Then draw the AOI in the data frame, double clicking to end. Use Features From (Option 2): If an existing polygon layer will be used to delineate the AOI, select the layer from the dropdown menu. Interval for Contours (Optional): Use the dropdown to select the desired contour interval. This is optional. However, if no contour value is selected the contours layer will not be created. Choose DEM Elevation Units: The default value is feet. To determine the elevation units of the DEM file, view the county_dem file in the Table of Contents and compare the high and low elevations to expected elevations in the county to determine if the elevations are in feet or meters. Then select the appropriate units from the dropdown. Click OK to run the tool. When the tool has completed successfully click Close. If desired, check the box to close the dialog box automatically when the tool completes successfully. This setting will be saved for future runs.

2. Create Contours By AOI Tool

Tool Products: Contours -- User can create contours on 2, 5, 10, or 20 ft. intervals with elevation labels and major and minor indexes. Steps to Run Tool: See Section C.2.a. Adding LiDAR Derived Data for instructions on how to add the DEM or DTM data if needed. The DEM or DTM must be added as a layer to the ArcMap project prior to running the tool. In the ArcToolbox window expand NRCS GIS Tools V1.1.2 → Field Office Tools → and double-click the 2. Create Contours by AOI Tool.

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Browse to and Select Workspace: This is the location that the GIS product data will be stored. (Reference A.2. File Structure and Data Management.) The file path cannot contain any spaces or special characters. Use the “navigate to folder” button to navigate to and select a workspace. (Note: Just select/highlight the folder to use as a workspace and click Add. Don’t double click and navigate into the workspace folder) Input DEM: Use the dropdown to select the county DEM or DTM. Do NOT use the DSM file. Add Features Interactively (Option 1): Select the drop down menu to the left of the Go To Folder icon. Select CreateContoursFromAOI::Enter_your_Area_of_Interest if the Area of Interest (AOI) will be drawn manually. Then draw the AOI in the data frame, double clicking to end. Use Features From (Option 2): If an existing polygon layer will be used to delineate the AOI, select the layer from the dropdown menu. Interval for Contours: Use the dropdown to select the desired contour interval. Choose DEM Elevation Units: The default value is feet. To determine the elevation units of the DEM file, view the county_dem file in the Table of Contents and compare the high and low elevations to expected elevations in the county to determine if the elevations are in feet or meters. Then select the appropriate units from the dropdown. Click OK to run the tool. When the tool has completed successfully, click Close.

3. Avg. Slope by AOI Tool

Tool Products: Computes the average slope for a defined AOI (typically a drainage area) and inserts a label with the average slope in percent within the AOI layer. Steps to Run Tool: Several methods may be used to create the AOI for use with the Avg. Slope tool. For any of these methods, the user must first run one of the following tools to obtain contours for a preliminary Area of Interest (AOIp) that is larger than the AOI:

1. Create Contours, Depth Grid, Hillshade, DEM tool or 2. Create Contours by AOI tool

Once the contours have been created for the AOI, use one of the following three methods to create the AOI for the average slope determination:

Method 1 – (not recommended) Create the AOI within the 3. Avg. Slope by AOI tool by manually

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delineating a polygon using the Add Features Interactively option. It is difficult to edit the AOI when completed with this method.

Method 2 – Manually draw the AOI using a graphic, before opening the 3. Avg. Slope by AOI tool. The

graphic can then be edited as needed to refine the AOI. After the graphic is complete, use the 3. Avg. Slope by AOI tool to manually delineate the AOI using the graphic as a guide with the Add Features Interactively: option.

Method 3 – Create a shapefile to delineate the AOI as described in Section C.2.d. Creating a Layer.

After the AOI has been delineated and saved as a shapefile, use the Select Features From: option in the tool to select the AOI shapefile.

See Section C.2.a. Adding LiDAR Derived Data for instructions on how to add the DEM or DTM data if needed. The DEM or DTM must be added as a layer to the ArcMap project prior to running the tool. In the ArcToolbox window expand NRCS GIS Tools V1.1.2 → Field Office Tools → and double-click the 3. Avg. Slope by AOI tool. Browse to and Select Workspace: This is the location where the GIS product data will be stored. (Reference A.2. File Structure and Data Management.) The file path cannot contain any spaces or special characters. Use the “navigate to folder” button to navigate to and select a workspace. (Note: Just select/highlight the folder to use as a workspace and click Add. Don’t double click and navigate inside the workspace folder) Input DEM: Use the dropdown to select the county DEM or DTM. Do NOT use the DSM file or dtm_hil. Add Features Interactively (Option 1): Select the drop down menu to the left of the Go To Folder icon. Select CalculateAverageSlope2::Enter_your_Area_of_Interest if the Area of Interest (AOI) will be drawn manually. Then draw the AOI in the data frame, double clicking to end. Use Features From (Option 2): If an existing polygon layer will be used to delineate the AOI, select the layer from the dropdown menu.

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Choose DEM Elevation Units: The default value is feet. To determine the elevation units of the DEM file, view the county_dem file in the Table of Contents and compare the high and low elevations to expected elevations in the county to determine if the elevations are in feet or meters. Then select the appropriate units from the dropdown. Click OK to run the tool. When the tool has completed successfully click Close on the Tool Dialog Window. If desired, check the box to close the dialog box automatically when the tool completes successfully. This setting will be saved for future runs.

4. Slope Raster by AOI (Percent) Tool Products: Creates a slope raster showing the slope of the land in a grid layout. The default slope classification (breakdown) is 0-3%, 3-6%, 6-12%, and >12%. Steps to Run Tool: See Section C.2.a. Adding LiDAR Derived Data for instructions on how to add the DEM or DTM data if needed. The DEM or DTM must be added as a layer to the ArcMap project prior to running the tool. In the ArcToolbox window expand NRCS GIS Tools V1.1.2 → Field Office Tools → and double-click the 4. Slope Raster by AOI (Percent) Tool. Browse to and Select Workspace: This is the location that the GIS product data will be stored. (Reference A.2. File Structure and Data Management.) The file path cannot contain any spaces or special characters. Use the “navigate to folder” button to navigate to and select a workspace. (Note: Just select/highlight the folder to use as a workspace and click Add. Don’t double click and navigate inside the workspace folder). Input DEM: Use the dropdown to select the county DEM or DTM. Do NOT use the DSM file. Add Features Interactively (Option 1): Select the drop down menu to the left of the Go To Folder icon. Select CalculatePercentSlope::Enter_your_Area_of_Interest if the Area of Interest (AOI) will be drawn manually. Then draw the AOI in the data frame, double clicking to end. Use Features From (Option 2): If an existing polygon layer will be used to delineate the AOI, select the layer from the dropdown menu.

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Choose DEM Elevation Units: The default value is feet. To determine the elevation units of the DEM file, view the county_dem file in the Table of Contents and compare the high and low elevations to expected elevations in the county to determine if the elevations are in feet or meters. Then select the appropriate units from the dropdown. Click OK to run the tool. When the tool has completed successfully, click Close. If desired, check the box to close the dialog box automatically when the tool completes successfully. This setting will be saved for future runs. Steps to Change the Slope Classification (Optional): Right-click on the slope raster in the Table of Contents (TOC) and select Properties… Select the Symbology Tab in the Layer Properties window. Use the Classes dropdown to select the number of slope ranges to have. Use the Color Ramp to select colors for the slope ranges. Click the Classify… button to select the slope ranges. In the Classification window adjust the break values to indicate the upper slope of each range desired. Click OK when finished

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In the Layer Properties windows, adjust the labels as desired. The adjusted labels will appear in the TOC view for the slope ranges. Click OK when finished.

5. Clip/Merge Adjacent DEMs/DTMs

Tool Products: Merges adjacent DEMs/DTMs so that other GIS tools can be run, in cases where the area of interest extends beyond one DEM/DTM. Important: Counties with different elevation units (feet, meters) cannot be merged using the tool. If your county is adjacent to a county with different elevation units and the two need to be merged, contact a GIS specialist for instruction to convert the units before running the tool. Steps to Run Tool: See Section C.2.a. Adding LiDAR Derived Data for instructions on how to add the DEM or DTM data if needed. The DEM or DTM from both counties must be added as a layer to the ArcMap project prior to running the tool. In the ArcToolbox window expand NRCS GIS Tools V1.1.2 → Field Office Tools → and double click the 5. Clip / Merge Adjacent DEMs Tool.

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Browse to and Select Workspace: This is the location that the GIS product data will be stored. (Reference A.2. File Structure and Data Management.) The file path cannot contain any spaces or special characters. Use the “navigate to folder” button to navigate to and select a workspace. (Note: Just select/highlight the folder to use as a workspace and click Add. Don’t double click and navigate inside the workspace folder) Add Features Interactively (Option 1): Select the drop down menu to the left of the Go To Folder icon. Select ClipMergeDEMs2::Enter_your_Area_of_Interest if the Area of Interest (AOI) will be drawn manually. Then draw the AOI in the data frame, double clicking to end. Use Features From (Option 2): If an existing polygon layer will be used to delineate the AOI, select the layer from the dropdown menu. Select Rasters to Clip and Merge: Note: The resulting raster will be assigned the coordinate system of the first layer selected. Use the dropdown to select two adjacent DEM/DTMs to merge. Click OK to run the tool. When the tool has completed successfully, click Close. If desired, check the box to close the dialog box automatically when the tool completes successfully. This setting will be saved for future runs.

6. Soil Data Request (ONLINE ONLY)

Tool Products: A soils layer containing spatial features with tabular data appended using the soil map unit key. The data source is NRCS Web Soil Survey, which is why this tool works only when an internet connection is available. The data layer will show soils by soil map unit key. Tabular data are summarized in the geoprocessing window upon successful completion of the tool. This tool can be used to obtain typical data for determining runoff characteristics of a watershed, such as the soil hydrologic group. IMPORTANT: Soil surveys are not intended to be accurate beyond a 1:12000 scale. Soils contain inclusions and require on-site investigations for many practices which occur at smaller scales than 1:12000.

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Steps to Run Tool: For the Soil Data Request tool, the only required data in your GIS project is a layer containing the AOI. In the ArcToolbox window expand NRCS GIS Tools v2.0 → Field Office Tools → and double click the 6. Soil Data Request (ONLINE ONLY) Tool. Feature Set: Select the AOI polygon created in any of the previous tools or an AOI created manually. Create a shapefile manually to delineate the AOI as described in Section C.2.d. Creating a Layer. After the AOI has been delineated and saved as a shapefile, browse to and open the AOI shapefile in the tool. Alternatively, the AOI file can also be added to the data view

using the “Add Data” button and then selected using the down menu button to choose the associated layer. IMPORTANT: The Feature Set cannot contain dashes, spaces or other special characters. Aggregation Method: Input an aggregation method for the Web Soil Survey query. The aggregation method will be used to reduce a set of attribute values to a single value that represents the map unit as a whole.

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Dominant Condition The aggregation method "Dominant Condition" first groups like attribute values for the components in a map unit. For each group, percent composition is set to the sum of the percent composition of all components participating in that group. These groups now represent "conditions" rather than components. The attribute value associated with the group with the highest cumulative percent composition is returned. If more than one group shares the highest cumulative percent composition, the corresponding "tie-break" rule determines which value should be returned. The "tie-break" rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie. The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred. Use Dominant Condition for Hydrologic Soil Group, Drainage Class, T Factor, Wind Erodibilty

Dominant Component The aggregation method "Dominant Component" returns the attribute value associated with the component with the highest percent composition in the map unit. If more than one component shares the highest percent composition, the corresponding "tie-break" rule determines which value should be returned. The "tie-break" rule indicates whether the lower or higher attribute value should be returned in the case of a percent composition tie. The result returned by this aggregation method may or may not represent the dominant condition throughout the map unit. Use for Available Water Content, Bulk Density, Liquid Limit, Organic Matter, Percent Clay, Percent, Sand, Percent Silt, Plasticity Index, Saturated Hydraulic Conductivity or any other value requiring a tie break rule and excluding inclusions.

Weighted Average The aggregation method "Weighted Average" computes a weighted average value for all components in the map unit. Percent composition is the weighting factor. The result returned by this aggregation method represents a weighted average value of the corresponding attribute throughout the map unit. Use for Available Water Storage or any other numeric value that could be significantly impacted by inclusions. Soil Property: Multiple soil properties may be selected within one aggregation method. These are the same soil properties that are present in Web Soil Survey. IMPORTANT: The tool will not run if any other soil property has been selected in any other aggregation method. To be sure no other property is being requested, first click Unselect All before choosing soil properties. Top Depth (optional): No value has to be selected. A top depth is specified to exclude surface horizons. An upper depth may be specified for all or part of more than one soil horizon, in which case horizon aggregation would need to be performed. Horizon aggregation is a weighted average of the corresponding soil property where layer thickness is the weighting factor. Bottom Depth (optional): No value has to be selected. A bottom depth is specified to exclude subsoil horizons. A lower depth may be specified for all or part of more than one soil horizon, in which case horizon aggregation would need to be performed. Horizon aggregation is a weighted average of the corresponding soil property where layer thickness is the weighting factor.

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Min/Max (optional): No value has to be selected. The resulting soil properties returned using the method represents with the minimum or maximum value of the corresponding attribute throughout the map unit. The result may be based on a map unit component of very minor extent. Output Location: The output location must be a file geodatabase (.gdb). This file geodatabase can be one created in the previous tools. Alternatively, if there is no geodatabase available from a run of the other tools in this set, use the ArcCatalog window in ArcMap. To open the ArcCatalog window, click the yellow file cabinet icon. Second, right click a folder and mouse over new, and select File Geodatabase. Finally, give the geodatabase a unique name. This can be done with the tool window open. Do Not include spaces in the geodatabase name.

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Click OK to run the tool. A message box will appear, providing updates on the progress of the tool. The message box will also show a summary of the soil data requested. Expand the size of the message box window to view the entire message. Make a screen capture if this information is desired for documentation. When the tool has completed successfully, click Close. The soils layer created by this tool will automatically be added to the GIS project with a default title “SSURGO_express_properties”. Right click on this layer in the Table of Contents to view the desired soil properties using “Open Attribute Table”. Notes: The results in the geoprocessing window can be saved as a results file (.rlt). To do so, go to the Geoprocessing menu at the top of the ArcMap window and click Results. Then right click the top most tool run and click Save As. This file can be opened in the Results window at a later time using the ArcCatalog window to find and double click on the .rlt file in the location in which it had been saved. The results file will appear under Shared in the results window. The newly created soil properties layer can be used to create a new layout for printing or saving as PDF for documentation purposes. To do so, change the layer symbology to depict the selected soil property. For more details see C.3 Changing Layer Symbology.

7. Troubleshooting Issue: My contour labels or average slope labels and contour lines are not formatting correctly.

Solution: If this occurs, rerun the tool after deleting the contents of the workspace folder, or run the tool selecting a different workspace folder.

Issue: My contour and/or AOI layer is showing up in a different place than all my other data.

Solution: This can occur when a user runs the tool in two separate coordinate systems without clearing the workspace folder contents. If this occurs, rerun the tool after deleting the contents of the workspace folder, or run the tool selecting a different workspace folder.

Issue: The tool has a red X symbol when I select my workspace.

Solution: The workspace path selected has invalid characters in the name. Refer to Section A.2. File Structure and Data Management.

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Issue: The contours created have elevations that are a lot higher or lower than normal in my area of interest. Solution: Review the original DEM or DTM elevation units and use the correct DEM Elevation Units: dropdown in the tool to select either feet or meters as appropriate.

Issue: The average slope seems way too high or way too low for my area of interest.

Solution: Review the original DEM or DTM elevation units and use the correct DEM Elevation Units: dropdown in the tool to select either feet or meters as appropriate.

Issue: ArcMap seems frozen after the tool has run, it added the map products but now I can’t do anything.

Solution: The tool dialog box is open. This must be closed after the tool has run. If the checkbox is checked the dialog, will automatically close when the tool completes successfully.

Issue: The tool dialog box states in red text that there is an error.

Solution: Clear the workspace folder files and review the user instructions for the tool. If the problem persists, contact the appropriate staff to assist in diagnosing the error.

Issue: When I add the GIS Tools layers to a map document, the layer symbology is not the same as when they were when created by the tool.

Solution: If the original map that the layers were created from is saved, this map can be opened and maintain the layer symbology as long as the source data file path has not moved. If it is desired to create layers that can be transferred and maintain symbology used by the tool see Section C.2.e. Saving a Layer File.

Issue: The contours I created have a bunch of little circle contours and do not look correct and the hillshade shows trees and buildings.

Solution: The DSM file was used to run the tool. Discard this information and rerun the tool using the DEM or DTM data.

Issue: When attempting to run tool #6 and make a soils data request an error occurs: Fatal. URL Error<urlopen error [Errno 11004] getaddrinfo failed>

Solution: There is no network connectivity. ArcMap, when being used on a USDA machine, requires connection to the USDA network and the tool only requires connection to the internet.

Fatal. HTTP ErrorHTTP Error 400: Bad Request

Solution: The request to the Soil Data Mart was a wrong shape, coordinates, projection, or other errors on the user’s end.

Fatal. HTTP ErrorHTTP Error 500: Internal Server Error (or other 500 error messages)

Solution: Try again later. The Soil Data Mart is down for maintenance and the issue is being fixed.

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C. BACKGROUND 1. LiDAR Map Products There are three LiDAR map products for the majority of counties in Illinois. County.dem or County.dtm – Digital Elevation Models (DEM) and Digital Terrain Models (DTM) are essentially the same for the basic use described in this guide. Each county with LiDAR data will have either a .dem or a .dtm file. The file contains a grid of bare-earth elevation values at regularly spaced intervals that are created from LiDAR point data. The bare-earth values have the trees, buildings, etc. removed from the elevation dataset so only the ground elevation data is used. An example of a DEM or DTM surface profile is shown below in the green line of the figure below. With the NRCS_GIS_Tool, use only the DEM or DTM layer. County.dsm – Digital Surface Model (DSM) is a grid of elevation values that include buildings, trees, etc. An example of a DSM surface profile is shown below in the red line of the figure below.

County_DEM_Hillshade or County_DTM_Hillshade and County_DSM_Hillshade – The hillshade rasters are shaded relief imagery where lighting effect is added to a map based on elevation variations within the landscape. A hillshade view is similar to that of a 3D clay molding of the landscape. Notice in the hillshade figures below that the DEM/DTM hillshade has the trees and buildings removed, whereas the DSM hillshade includes them.

DEM/DTM Hillshade DSM Hillshade

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The DEM/DTM and DSM hillshade products can have an aerial photography overlay, shown below. Instructions for setting up a hillshade with an aerial photo overlay are located in Section C.2.c.

DEM/DTM hillshade with aerial photo overlay DSM hillshade with aerial photo overlay

Viewing the DEM/DTM and/or DSM hillshade with aerial photography can help the user visualize a site. Select one or the other depending on at the intended use of the imagery.

2. General ArcMap Procedures for use with Tool a. Adding LiDAR Derived Data:

If the DEM or DTM layer is not already added to

ArcMap, click the Add Data button and navigate to and select the county_dem or county_dtm file. Do NOT add the DSM file for use with the LiDAR Tool Select the file and click Add The DEM or DTM layer will be added to the ArcMap Table of Contents

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b. Checking Spatial Reference of a Layer:

Right-click on the DEM layer in the Table of Contents and select Properties… Select the Source Tab and scroll down to the Spatial Reference section to view the coordinate system of the layer. Knowing the coordinate system of the DEM/DTM file will be important when using the GIS Tools. Write this down for easier reference later on.

c. Setting up hillshade with aerial photo overlay:

Add the aerial map and County_DSM_Hillshade or County_DEM_Hillshade layer. For instruction on adding map layers see Section C.2.a, Adding LiDAR Derived Data. The goal in this section is to make the hillshade layer somewhat transparent, so that the aerial photo layer just below shows through. Right-click on the hillshade layer in the Table of Contents and select Properties. On the Display tab adjust the transparency. (50% is a good place to start.)

Click OK Make sure the hillshade layer is above the aerial photo layer in the Table of Contents (TOC) and turn both layers on (select the checkboxes in the TOC). To move layers relative to each other, click and drag the layer to the desired position in the TOC. The order in which the layers are listed represents the order of the layers in the overlay. d. Creating a Layer to use as the AOI (i.e. Drainage Area) NOTE: This section contains two ways of creating and saving a graphic as a shapefile so it can be added as a layer in the ArcMap project. There are many other ways of doing this, so use the way you feel most comfortable with.

i. IF YOU HAVE TOOLKIT

If you don’t have Toolkit, skip to ii. on the next page.

Select the ArcCatalog button on the Standard Toolbar

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Or

Select Windows → Catalog from the menu bar.

In the Catalog window browse to the folder where the Layer will be stored. The file path for the layer file cannot contain any special characters or spaces. Make sure you change the dropdown file type to .shp Shapefile. Also, don’t save this shapefile to your “LiDAR Temp” file you created in step A.2. File Structure and Data Management on page 5, which is subject to frequent cleanout.

Right-click on the folder where the layer will be stored and select New → Shapefile…

In the Create New Shapefile window enter a Name: for the shapefile.

Use the Feature Type: dropdown to select Polygon. In the spatial reference box select Edit… In the Spatial Reference Properties Window click Select… In the Browse for Coordinate System window, browse to and select the coordinate system that your DEM data is in. See Section C.2.b, Checking Spatial Reference of a Layer. Click Add to close the “Browse for Coordinate System” window. The selected coordinate system information will show up in the “Spatial Reference Properties” window. Click OK to close this window. Click OK to close the “Create New Shapefile” window The newly created shapefile will then be added to the Table of Contents. At this point, the shapefile will have no polygons yet. If the Polygon Editor toolbar is not already added to ArcMap, select Customize → Toolbars → and select Polygon Editor.

On the Polygon Editor toolbar select Editor → Start Editing. Use the dropdown in the “Select a Layer to Edit” window to select the layer that was just created. Use the Polygon Editor toolbar to draw the Area of Interest (AOI).

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When finished select Editor → Stop Editing. Click Yes to save edits to the layer. The layer can then be selected from the “Use Features From:” dropdown in each of the tools.

ii. IF YOU DON’T HAVE TOOLKIT – Creating a Layer to use as the AOI (i.e. Drainage Area)

If you don’t have the Draw toolbar open, click Customize → Toolbars → and select Draw. On the Draw toolbar, select the Polygon tool.

Draw your Area of Interest (drainage area) by left clicking a series of points. Double click the last point to finish drawing the polygon. The resulting polygon will be a selected graphic, represented by a square with a dotted outline with boxes at the corners and sides.

With the watershed graphic still selected, in the Draw toolbar, click Drawing → Convert Graphics to Features...

Ensure the “Selected graphics only” box is checked, and that only one graphic (your AOI/DA) is selected. In the “Output shapefile or feature class” line, browse to an output folder and name the output shapefile (your new AOI/DA layer). Remember, the file path for the layer file cannot contain any special characters or spaces. Make sure you change the dropdown file type to .shp Shapefile. Also, don’t save this shapefile to your “LiDAR Temp” file you created in A.2. File Structure and Data Management on page 5.

Polygon (Background maps removed for clarity)

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Check the box “Automatically delete graphics after conversion.” Click OK. A box will pop up and ask “Do you want to add the exported data to the map as a layer?” click Yes.

e. Saving and Retrieving a Layer File A user may want to run the GIS Tool and save the created map layers for future use for training or to transfer the files to another user. This is not a recommended practice for normal use as it may create storage issues due to the large size of the files produced. When the tool creates the layers, the layers have associated layer symbology. Saving the .mxd file after the GIS Tools layers are created will allow the user to open the map again and maintain the layer symbology until the .gdb data is deleted or file paths are changed. To transfer the layers with the symbology to another map or user, save a layer file to store the symbology properties along with transferring the .gdb folder for the specific tool.

Create the map products using the GIS Tools toolbox. Right-click on the layer to be saved in the Table of Contents and select Save As Layer File…

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Navigate to a folder. RECOMMENDATION: Navigate to the same folder that was selected as the workspace when the tool was run: Run1 in this example. Give the file a unique name and click Save. To add the layer in a different ArcMap document,

click the Add Data button and navigate to the folder where the layer file has been saved. Select the layer and click Add.

To correct an error where the layer appears in the Table of Contents with a red exclamation point, the data source of the layer will need to be reset. This can happen if the file path changed (for example, the file and .gdb folder were copied to a new location). To reset the data source, right click on the layer in the Table of Contents and select Properties… In the Layer Properties window select the Source tab and select the Set Data Source… button.

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In the Data Source window, browse to the .gdb folder and select the layer to be displayed. Click Add. Click OK to close the Layer Properties Window.

3. Changing Layer Symbology Locate the layer in the Table of Contents, right click and select Properties at the bottom of the pop up menu. Select the Symbology tab, then Unique Values under Categories. The Value Field should reflect the column in the Attribute Table which will be depicted with varying colors. In the case of this example, hydrologic soil group (hydgrp) will be used. Then select Add All Values in the lower left.

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The colors associated with each hydrologic soil group may be changed after adding all the values. Use the green to red ramp to create a map that replicates one from Web Soil Survey. The None value can also be changed individually by double left clicking the color and changing to a lake color; the None value is usually water. Click Apply and then OK. The resulting map to the left is what the example looks like after altering the symbology to depict varying hydrologic soil groups. Now a layout can be produced using this layer to print and save for documentation.