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Exurban and Land Use Planning
Tools is a collection of tools designed to support land use decision making for
conservation. The toolbox includes tools to assist conservationists and landuse planners with desiging
landscapes that provide secure living habitat and/or allow movement habitat
connectivity for wildife.
Two general categories of tools
are provided. Policy tools are designed to estimate the potential impact on
wildlife resulting from specific land use policy decisions such as establishing
density zoning regulations. Evaluation tools are designed to evaluate existing
or proposed landscapes for impacts on wildlife. Evaluation tools are
particularly helpful to allow developers, land use planners, and
conservationists to explore the impacts of mulitple
scenarios of structure and road placement on widllife.
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Calculate Target Housing Density is designed for
estimating an appropriate housing density that will meet specific wildlife
conservation targets. The user specifies the minimum area requirement for core
habitat and a disturbance distance.
The tool uses iterative
When the final solution is reached, a message box
displays the density of houses (in acres) that satisfied the target parameters.
Outputs include a summary table of all simulation runs, and example shapefiles of cores and houses representing the final
simulation that satisfied target parameters.
Figure 1 Example output of Calculate Target Density
HINT: Using ‘multipart to singlepart’
to convert a multipart analysis extent layer to a single part layer can
dramatically improve processing speed.
Constraint layer: A constraint layer can be used
to constrain random structure placement to areas where actually development is
most likely to occur. In most cases, public lands areas protected by
conservation easement, or otherwise unsuitable building sites should be removed
from the constraint layer to provide a more realistic simulation for analysis.
CalcTargetDensity <Output_Table>
Parameters
Expression |
Explanation |
<Output_Table> |
The name of a table where summary data will be
stored. |
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The number of iterations to run each |
<Analysis_Extent> |
Polygon layer to be used as boundary for
analysis extent. This layer must have a projection with units in meters. |
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Polygon layer used to confine the random
placement of houses. This layer must be in same projection as, and overlap
with, the Analysis Extent. Specifying a Constraint Layer is useful for
masking out areas that cannot be developed. If no Constraint Layer is
specified, houses will be placed randomly throughout polygons contained in
the Analysis Extent. |
<Minimum_Habitat_Core> |
The minimum habitat core area requirements for
the target species. |
<Disturbance_Distance> |
The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. This value
must be specified in square meters. |
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The percentage of the analysis area you wish to
conserve as core (undisturbed) habitat for the target species. This must be
an integer value from 1 - 100. |
Command Line Example
CalcTargetDensity (Output_Table,
Number_of_Iterations, Analysis_Extent,
Constraint_Layer, Minimum_Habitat_Core,
Disturbance_Distance, Percent_Area_to_Conserve)
Parameters
Expression |
Explanation |
Output Table (Required) |
The name of a table where summary data will be
stored. |
Number of Iterations
(Optional) |
The number of iterations to run each |
Analysis Extent
(Required) |
Polygon layer to be used as boundary for
analysis extent. This layer must have a projection with units in meters. |
Constraint Layer
(Optional) |
Polygon layer used to confine the random
placement of houses. This layer must be in same projection as, and overlap
with, the Analysis Extent. Specifying a Constraint Layer is useful for
masking out areas that cannot be developed. If no Constraint Layer is
specified, houses will be placed randomly throughout polygons contained in
the Analysis Extent. |
Minimum Habitat Core
(Required) |
The minimum habitat core area requirements for
the target species. |
Disturbance Distance
(Required) |
The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. This value
must be specified in square meters. |
Percent Area to
Conserve (Optional) |
The percentage of the analysis area you wish to conserve
as core (undisturbed) habitat for the target species. This must be an integer
value from 1 - 100. |
Script Example
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Calculate Target Housing Density is designed for estimating
an appropriate housing density that will meet specific wildlife conservation
targets. The user specifies the minimum area requirement for core habitat and a
disturbance distance.
The tool uses iterative
When the final solution is reached, a message box displays the
density of houses (in acres) that satisfied the target parameters. Outputs
include a summary table of all simulation runs, and example shapefiles
of cores and houses representing the final simulation that satisfied target
parameters.
Figure 1. Example output. A
random pattern of structures at a density that produces an average distance
between structures equal to the target value provides high probababilty
that the landscape matrix is permeable for the target species. One of many
possible movement routes is indicated by the dashed arrow.
HINT: Using ‘multipart to singlepart’
to convert a multipart analysis extent layer to a single part layer can
dramatically improve processing speed.
CalcTargetDensity2 <Output_Table>
Parameters
Expression |
Explanation |
<Output_Table> |
The name of a table where summary data will be
stored. |
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The number of iterations to run each |
<Analysis_Extent> |
Polygon layer to be used as boundary for
analysis extent. This layer must have a projection with units in meters. |
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Polygon layer used to confine the random
placement of houses. This layer must be in same projection as, and overlap
with, the Analysis Extent. Specifying a Constraint Layer is useful for
masking out areas that cannot be developed. If no Constraint Layer is
specified, houses will be placed randomly throughout polygons contained in
the Analysis Extent. |
<Minimum_Corridor_Width> |
The mimimum width of
undisturbed habitat the target species requires for movement security. |
<Disturbance_Distance> |
The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. This value
must be specified in square meters. |
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Select the units for reporting output densities. |
Command Line Example
CalcTargetDensity2 (Output_Table, Number_of_Iterations,
Analysis_Extent, Constraint_Layer,
Minimum_Corridor_Width, Disturbance_Distance,
Output_Units)
Parameters
Expression |
Explanation |
Output Table (Required) |
The name of a table where summary data will be
stored. |
Number of Iterations
(Optional) |
The number of iterations to run each |
Analysis Extent
(Required) |
Polygon layer to be used as boundary for
analysis extent. This layer must have a projection with units in meters. |
Constraint Layer
(Optional) |
Polygon layer used to confine the random
placement of houses. This layer must be in same projection as, and overlap
with, the Analysis Extent. Specifying a Constraint Layer is useful for
masking out areas that cannot be developed. If no Constraint Layer is
specified, houses will be placed randomly throughout polygons contained in
the Analysis Extent. |
Minimum Corridor
Width (Required) |
The mimimum width of
undisturbed habitat the target species requires for movement security. |
Disturbance Distance (Required)
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The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. This value
must be specified in square meters. |
Output Units
(Optional) |
Select the units for reporting output densities. |
Script Example
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Evaluate Habitat Patches measures the percent area of
landscape within the analysis area remaining and generates a shapefile of the results.
This tool buffers structures and roads input layers by the
disturbance distance to simulate habitat fragmentation created by structures
and roads. The resulting habitat patches are evaluated by applying the minimum
core size threshold.
Evaluate Habitat Patches is suitable for testing existing
landscapes or for scenario testing to help land use planners design landscapes
that maximize wildlife conservation value.
Figure 1. Example output showing habitat blocks that
exceed specified minimum patch size.
Analysis Extent: Outputs are clipped to polygons contained
in the analysis extent layer. For best results, the analysis extent should be
limited to areas of suitable habitat for the target species.
Using ‘multipart to singlepart’ to
convert a multipart analysis extent layer to a single part layer can
dramatically improve processing speed.
EvaluateHabitatCores <Output_Table> <Analysis_Extent>
<Structures_Layer> <Roads_Layer>
<Minimum_Habitat_Core> <Disturbance_Distance>
Parameters
Expression |
Explanation |
<Output_Table> |
The name of a table where summary data will be
stored. |
<Analysis_Extent> |
Polygon layer to be used as boundary for
analysis area. This layer must have a projection with units in meters.
Analysis outputs are clipped to the polygon(s) contained in this layer. For
most accurate results, the analysis area should be limited to areas
containing suitable habitat for the target species. HINT: Using dissolve to convert a multipart
analysis extent layer to a single part layer can dramatically improve
processing speed. |
<Structures_Layer> |
A point layer representing the location of
structures on the landscape. |
<Roads_Layer> |
A line layer representing the placement of roads
on the landscape. |
<Minimum_Habitat_Core> |
The minimum habitat core area requirements for
the target species. |
<Disturbance_Distance> |
The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. |
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Select the units for reporting output densities. |
Command Line Example
EvaluateHabitatCores (Output_Table,
Analysis_Extent, Structures_Layer,
Roads_Layer, Minimum_Habitat_Core,
Disturbance_Distance, Output_Units)
Parameters
Expression |
Explanation |
Output Table (Required) |
The name of a table where summary data will be
stored. |
Analysis Extent
(Required) |
Polygon layer to be used as boundary for
analysis area. This layer must have a projection with units in meters.
Analysis outputs are clipped to the polygon(s) contained in this layer. For
most accurate results, the analysis area should be limited to areas containing
suitable habitat for the target species. HINT: Using dissolve to convert a multipart
analysis extent layer to a single part layer can dramatically improve
processing speed. |
Structures Layer
(Required) |
A point layer representing the location of
structures on the landscape. |
Roads Layer
(Required) |
A line layer representing the placement of roads
on the landscape. |
Minimum Habitat Core
(Required) |
The minimum habitat core area requirements for
the target species. |
Disturbance Distance
(Required) |
The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. |
Output Units
(Optional) |
Select the units for reporting output densities. |
Script Example
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Evaluate Movement Landscape identifies areas that may potential provide adequate wildlife movement habitat
based on the location of structures and user specified input parameters. This
tool is intended for fine-scale analysis within areas identified as potential
wildlife corridors to identify areas important for maintaining habitat connecitivity within an existing landscape, or to evaluate
the potential impact of a proposed development on wildlife habitat
connectivity.
This tool requires a spatial analyst license. Areas
suitable for animal movement are first identified by calculating euclidian distance from each cell in the analysis area to
the nearest structure. Areas beyond the specified disturbance distance are
considered potential movement areas. Next areas within the potential movement
landscape that are equal to, or greater than, the minimum corridor width
specified are identified by calculating the euclidian
distance from the nearest disturbed area boundary and calculating the focal
maximum using a circular neighborhood with radius equal to one half the minimum
corrdor width. Cells with a focal max greater than
one half the minimum corridor width are coded as
suitable for animal movement.
Figure 1. Example of final output raster
showing potential movement areas.
Using a relatively small cell size produces the most
accurate results but may significantly increase processing time and disk
storage requirements for the final output. If no cell size is specified, the default
cell size is Minimum Corridor Width ÷ 30 which is usually sufficient to produce
a good result. If large areas must be analyzed, we recommend dividing the
analysis area into two or more overlapping analysis extents rather than
increasing the cell size. Final results can be mosaiced
into a single output raster by specifying 'maximum' as the mosaic type.
Specifying an analysis extent layer is optional. If no
analysis extent is specified, it will be set to the extent of the input
structures layer. In most cases an analysis extent should be specified that is
larger than the extent of the structures layer and the extent should include
all areas between source habitats between which habitat
connectivity is desired for the target species.
EvaluateMovementLandscape <Structures_Layer> <Minimum_Corridor_Width>
<Disturbance_Distance> <Output_Raster>
Parameters
Expression |
Explanation |
<Structures_Layer> |
A point layer representing the location of
structures on the landscape. |
<Minimum_Corridor_Width> |
The minimum width of undisturbed area required
for the target species to move freely. |
<Disturbance_Distance> |
The distance from roads and houses the target species
is likely to avoid or where habitat quality is degraded. |
<Output_Raster> |
The name and location of the output raster to
store the results. Cell values of the output raster are 1 for areas suitable
for animal movement and 0 for areas that are less likely to be used as
movement habitat by the target species. |
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The cell size to use for analysis. Relatively
small cell sizes produce more accurate results but may significantly increase
processing times and disk storage requirements. See 'Usage Tips' under help
for more information. If analysis cell size is not specified, it will be set
to Minimum Corridor Width ÷ 30. |
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Extent to be used as boundary for analysis area.
For most accurate results, the analysis area should be large enough to
include all area between source habitats where wildlife habitat connectivity
is desired. If no extent is specified, the analysis area will be the extent
of the input structures layer. |
Command Line Example
EvaluateMovementLandscape (Structures_Layer,
Minimum_Corridor_Width, Disturbance_Distance,
Output_Raster, Analysis_Cell_Size,
Analysis_Extent)
Parameters
Expression |
Explanation |
Structures Layer (Required) |
A point layer representing the location of
structures on the landscape. |
Minimum Corridor
Width (Required) |
The minimum width of undisturbed area required
for the target species to move freely. |
Disturbance Distance
(Required) |
The distance from roads and houses the target
species is likely to avoid or where habitat quality is degraded. |
Output Raster
(Required) |
The name and location of the output raster to
store the results. Cell values of the output raster are 1 for areas suitable for
animal movement and 0 for areas that are less likely to be used as movement
habitat by the target species. |
Analysis Cell Size
(Optional) |
The cell size to use for analysis. Relatively
small cell sizes produce more accurate results but may significantly increase
processing times and disk storage requirements. See 'Usage Tips' under help
for more information. If analysis cell size is not specified, it will be set
to Minimum Corridor Width ÷ 30. |
Analysis Extent
(Optional) |
Extent to be used as boundary for analysis area.
For most accurate results, the analysis area should be large enough to
include all area between source habitats where wildlife habitat connectivity
is desired. If no extent is specified, the analysis area will be the extent
of the input structures layer. |
Script Example