ConvertLidar

class lidar.ConvertLidar(lidar_shp, fishnet_shp, new_lidar)

Bases: object

The ConvertLidar class is used to generate a CAPSIS tree list of lidar tree attributes from a shapefile of lidar trees.

Parameters:

• lidar_shp (string) – name and path of input lidar shapefile.
• fishnet_shp (string) – name and path for output fishnet shapefile.
• new_lidar (string) – name and path for output lidar shapefile.

Methods (execution order):

• verify_projection
• verify_input_fields
• calculate_extents
• create_fishnet
• copy_shapefile
• cleanup_lidar_fields
• fishnet_id
• cleanup_lidar_features
• add_attribute_fields
• calculate_attribute_fields
• number_trees
• export_attributes_to_csv

add_attribute_fields()

Adds and defines new attribute fields to the output shapefile.

Fields added:

Field Name	Type	Description
POINT_X	Float	X coordinate
POINT_Y	Float	Y coordinate
CR_code	Integer	FVS crown ratio code
DBH_in_x10	Integer	Diameter at Breast Height in inches x 10
Height_ft	Integer	Tree height in feet
Tree_ID	Integer	Unique tree ID number within each plot

Returns:add attribute fields success Return type:boolean Returns:add attribute fields message Return type:string

calculate_attribute_fields()

Calculates values for the attribute fields added in the “add_attribute_fields” method.

Formula descriptions:

• Height- converts from meters to feet and rounds to integer
• DBH - converts from centimeters to inches*10 and rounds to integer
• CR_code- calculates crown ratio while accounting for anomolous data where Height is <= CBH. Then classifies the crown ratio into FVS categories.
  • crown ratio = (height - crown base height)/height).
  • FVS crown ratio codes: 1: 0-10%; 2: 11-20%;…; 9: 81-100%

Returns:calculate attribute fields success Return type:boolean Returns:calculate attribute fields message Return type:string

calculate_extents()

Calculates the minimum and maximum x and y extents of the input shapefile.

Returns:x min, x max, y min, y max Return type:list of four floats

cleanup_lidar_features()

Deletes features outside the fishnet area.

Returns:cleanup success Return type:boolean Returns:cleanup message Return type:string

cleanup_lidar_fields()

Deletes extraneous fields from output shapefile.

Returns:cleanup success Return type:boolean Returns:cleanup message Return type:string

copy_shapefile()

Makes an exact copy of the input lidar shapefile for use in creating the output lidar shapefile.

Returns:shapefile copy success Return type:boolean Returns:shapefile copy message Return type:string

create_fishnet(extents)

Creates a fishnet polygon shapefile to be used to assign plot numbers to the lidar points. Fishnet cells are 64x64m (~1 acre). Feature ID numbers are used to number plots.

Parameters:extents (list of four floats) – x min, x max, y min, y max of the input shapefile Returns:fishnet creation success Return type:boolean Returns:fishnet creation message Return type:string

export_attributes_to_csv(lidar_csv)

Exports select attributes in the new lidar shapefile to a text (.csv) file.

Exported attributes:

Name	Description
FID	GIS record ID number
POINT_X	X coordinate
POINT_Y	Y coordinate
Species	Two letter FVS species code
CR_code	FVS crown ratio code
DBH_in_x10	Diameter at Breast Height in inches x 10
Height_ft	Tree height in feet
Plot_ID	Unique plot ID number
Tree_ID	Unique tree ID number within each plot

Parameters:lidar_csv (string) – name and path for output text file Returns:export success Return type:boolean Returns:export message Return type:string

fishnet_id()

Assigns a fishnet-based plot ID number to each tree in the output shapefile.

Returns:plot number assignment success Return type:boolean Returns:plot number assignment message Return type:string

number_trees()

Numbers trees within each 64x64m (~1 acre) plot. The combination of plot ID and tree Id constitutes a unique identifier for each tree in the simulation.

Returns:numbering trees success Return type:boolean Returns:numbering trees message Return type:string

verify_input_fields()

Verifies that the required input fields are in the input shapefile.

Required fields:

Field Name	Type	Units	Description
X_UTM	Float	Meters	X coordinate
Y_UTM	Float	Meters	Y coordinate
Height_m	Float	Meters	Tree height
CBH_m	Float	Meters	Crown Base Height
DBH_cm	Float	Centimeters	Diameter at Breast Height
Species	String	Text	Two letter FVS species code

Returns:input field fitness Return type:boolean Returns:fitness message Return type:string

Note

See FVS variant users guides for definitions of species codes: https://www.fs.fed.us/fvs/documents/guides.shtml

verify_projection()

Verifies that the input shapefile is projected and, if so, whether the projection is WGS 1984 UTM. Uses EPSG projection codes to verify.

Returns:projection fitness Return type:boolean Returns:fitness message Return type:string Returns:fitness code Return type:integer

Fitness Codes:

• 0 - projection ok
• 1 - unable to identify projection
• 2 - unprojected