InventoryManger: Plot Layout

Overview

The Plot Layout tool can be used to lay out a uniform grid of sample points (plots) for inventory data collection. Once plots are created and saved in Inventory Manager, they will be available across for users to download to MobileMap and take into the field on a mobile device.  Before layout out plots, a user must first select an existing stand polygon.  Currently the tool cannot be used to generate plots on more than one stand polygon.  If you need to create plots for more than one stand, repeat the process below for each stand.   For more information on the algorithm used to lay out plots, see MobileMap: Plot Layout.

Workflow

1. Select a stand polygon by clicking on the map or using the Search tool.  Note that you must have only one stand selected for the Plot Layout tool to work.  If you click on the stand and it does become selected, verify that you have the stands layer (or no layer) selected in the Search tool.

2. Click on 'Plots' to display the Plot Layout tool

3. Enter the layout parameters

4. Click 'Lay Out Plots' to create the plot locations based on the layout parameters.  Note that this step will also pre-populate any attribute fields that are set to be inherited from the stand.  Field inheritance is configured by your administrator in the Inventory Project.

5. Enter the appropriate attribute information. 

6. Click 'Save Plots' complete the process and save the plots.

Note that the required information in the bottom section shown light gray may vary depending on the cruise requirements. This form is pre-populated with required fields and inherited attribute fields as described above. This example shows one of the more detailed forms.

Open

Design

There are three main options for the design:

Plot Count - Use a pre-defined number of plots regardless of the stand size. For this option input the desired number of plots to the Plot Count input.

Plot Density - Determine the number of plots based on the size of the stand, using a user-supplied plot density, or acres per plot. Enter the number of acres per plot. Example: enter '2' to achieve a plot density of 1 plot for every 2 acres.

Plot Spacing - Use a pre-defined spacing between plots. Enter the desired spacing between plots, in feet, for the X (East-West) dimension. If an X:Y is left at 1, this will also be the spacing for the Y (North-South) dimension. If the X:Y ratio is not 1 then the Y spacing will be calculated by multiplying the ratio times the X spacing.

Open

Layout Pattern

Two pattern options are available: Rectangle and Diamond. Rectangle will result in a checkerboard or square grid (right), while Diamond will result in a windowed or X plot formation (below).

X:Y Ratio

Change these values to modify the ratio of horizontal to vertical spacing along the grid. The default ratio is 1:1.

Starting Plot ID

Users can dictate the starting number for plots laid out in a polygon. This is especially useful in minimizing duplicate plot ID's in a large cruise. 

X and Y Offsets (Optional)

For most implementations of InventoryManager, a random X and Y offset is used for each attempt to layout plots. This introduces another random element to help prevent biased plot distributions. Some clients have requested the ability to set the X and Y Offset manually. This can be helpful, in combination with the ‘Plot Spacing’ design option to achieve a very specific plot layout.

In the example below, the first plot in the layout (upper left or Northwest-most plot) would be 100 feet to the South and 50 feet to the west of the Northwest corner of the Stand’s bounding box.

Lay Out Plots

Click the Lay Out Plots button in the bottom right corner of the plot wizard to generate plots. Note: No plots will be created unless a polygon feature is selected.

View the generated plot layout in the map. If the layout needs revision, adjust the layout parameters above and click Lay Out Plots again. The original set of plots will be wiped out, and a new set will be generated from a randomly selected starting point along the polygon boundary.

Below are three examples of plot layouts generated using the same criteria, but starting from a different, randomly selected point each time. 

Enter Plot Attributes

Once the desired layout is achieved, use the lower part of the form to enter in the plot attributes.  Some fields may be pre-populated with information inherited from the parent polygon.  Note that required fields are indicated with an asterisk (*). Users will be notified, and the tool will not run, if a required field is omitted. 

Some attributes may be configured to support ratios - where different values are applied to different plots.  The most common scenario is where a proportion of all plots (e.g., 1/3) include nested plots.  When an attribute field has been configured to support ratios there will be a small checkbox to the right of the field name indicating that ratios are supported.  Checking this box will change the single attribute input into 2 inputs, with associated ratio inputs.  In the example below the user wishes to create plots in which 1 plot out of every 3 includes a nested plot on which residuals are measured.  If every other plot were to include residuals, the ratio values would be 1 and 1.

Save Plots

Click 'Save Plots' to complete the process and add the new plots to the layer. Users will be notified if required fields are omitted. If the plots are successfully saved, the map will display the updated plot symbols (and labels if plot labels are being used) and it will zoom to the plot locations.