Tree Canopy Change, 2010-2015 Allegheny County, PA

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:Jarlath O'Neil-Dunne, University of Vermont, Director, Spatial Analysis Laboratory

Publication_Date:202507

Title:

Tree Canopy Change, 2010-2015 Allegheny County, PA

Edition:Second

Geospatial_Data_Presentation_Form:vector digital data

Description:

Abstract:

The purpose of this project was to conduct an assessment of tree canopy change that occurred between 2015 and 2020 utiliing LiDAR data and a previously prepared canopy dataset. Comprehensive canopy change statistics are provided for various geographies down to the parcel-level scale. This tree canopy change data set consists of three classes: no change, gain, and loss. No change polygons are those in which the tree canopy remained the same between the two time periods. Gain polygons are those in which tree canopy increased between the two time periods. Loss polygons are those in which tree canopy decrease between the two time periods. 2010 tree canopy can be calculated by adding the “no change” and loss classes. Tree canopy for 2015 can be calculated by adding the “no change” and “gain” classes.Several data sets were used to map tree canopy change. The starting point was the 2010 high-resolution land cover data set developed for Allegheny County. Change was then mapped using leaf-off lidar data collected in 2006, 4-band leaf-on National Agriculture Imagery Program (NAIP) data collected in 2010, leaf off lidar data collected in 2015, and 4-band leaf-on NAIP data collected in 2015. All four data sets were integratedinto an object-based image analysis system (OBIA), which a rule-based expert system. A combination of segmentation, classification, and morphology algorithms were employed to determine if tree canopy had changed between the two time periods. The data set was then manually edited at a scale of 1:5000. The main factors determining change were a decrease in height, indicating tree removal, as identified by the lidar, and the change in the spectral characteristics, as identified in the aerial imagery. There were spatial misalignment issues between all four of the data sets. As a result, very fine scale changes at the edges of tree canopy could not be determined. The data set can thus be considered to be slightly biased towards tree canopy loss, and fine-scale tree canopy gains could not be determined. Most of the gain identified is not new growth, but rather canopy from trees that were too small to be detected in the original 2010 mapping.The incorporation of newer lidar data enabled a revisit of the original 2010 tree canopy mapping. The 2015 lidar data was substantially higher quality than the 2006 lidar data used for the 2010 high-resolution land cover mapping project. This enabled errors of omission and commission in the original 2010 tree canopy mapping to be corrected. Examples include shrubby areas in 2010 falsely classified as tree canopy and tall trees that were not clearly visible in the data used to map tree canopy in 2010. This data set should be considered to be the most accurate depiction of tree canopy for both the 2010 and 2015 time periods.

Purpose:

The purpose of this project was to conduct an assessment of tree canopy change that occurred between 2015 and 2020 utiliing LiDAR data and a previously prepared canopy dataset. Comprehensive canopy change statistics are provided for various geographies down to the parcel-level scale.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date:20100801

Ending_Date:20150801

Currentness_Reference:

The data are valid for understanding tree canopy change from the summer of 2010 to the summer of 2015.

Status:

Progress:Complete

Maintenance_and_Update_Frequency:None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate:-80.368057

East_Bounding_Coordinate:-79.677803

North_Bounding_Coordinate:40.682772

South_Bounding_Coordinate:40.185665

Keywords:

Theme:

Theme_Keyword_Thesaurus:ISO 19115 Topic Categories

Theme_Keyword:environment

Theme:

Theme_Keyword_Thesaurus:None

Theme_Keyword:Tree Canopy

Theme_Keyword:Change Detection

Theme_Keyword:Land Cover

Access_Constraints:None

Use_Constraints:

The University of Vermont makes no representations of any kind, including but not limited to the warranties of merchantability or fitness for a particular use, nor are any such warranties to be implied with respect to the data.

Data_Set_Credit:

Tree Pittsburgh and the University of Vermont

Native_Data_Set_Environment:

Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.4.1.5686

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Tree canopy change attributes were reviewed at a scale of 1:5000.

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Explanation:

Manual review

Logical_Consistency_Report:

Topologically correct for overlaps and free of geometric errors.

Completeness_Report:

Mapped to the extent of Allegheny County

Lineage:

Source_Information:

Type_of_Source_Media:onLine

Source_Contribution:

Lidar, 2006

Source_Information:

Type_of_Source_Media:onLine

Source_Contribution:

Lidar, 2015

Source_Information:

Type_of_Source_Media:onLine

Source_Contribution:

NAIP, 2010

Source_Information:

Type_of_Source_Media:onLine

Source_Contribution:

NAIP, 2015

Source_Information:

Type_of_Source_Media:onLine

Source_Contribution:

2010 high-resolution land cover

Process_Step:

Process_Description:

Automated tree canopy change mapping

Process_Date:20160906

Process_Step:

Process_Description:

Manual review

Process_Date:20160916

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method:Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type:GT-polygon composed of chains

Point_and_Vector_Object_Count:842753

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Lambert_Conformal_Conic:

Standard_Parallel:39.93333333333333

Standard_Parallel:40.96666666666667

Longitude_of_Central_Meridian:-77.75

Latitude_of_Projection_Origin:39.33333333333334

False_Easting:1968500.0

False_Northing:0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method:coordinate pair

Coordinate_Representation:

Abscissa_Resolution:0.000000026907964745248598

Ordinate_Resolution:0.000000026907964745248598

Planar_Distance_Units:foot_us

Geodetic_Model:

Horizontal_Datum_Name:D North American 1983

Ellipsoid_Name:GRS 1980

Semi-major_Axis:6378137.0

Denominator_of_Flattening_Ratio:298.257222101

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label:Tree Canopy Change

Entity_Type_Definition:

Internal

Entity_Type_Definition_Source:

Project specific

Attribute:

Attribute_Label:FID

Attribute_Definition:

Internal feature number.

Attribute_Definition_Source:

Esri

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label:Shape

Attribute_Definition:

Feature geometry.

Attribute_Definition_Source:

Esri

Attribute_Domain_Values:

Unrepresentable_Domain:

Coordinates defining the features.

Attribute:

Attribute_Label:Change

Attribute_Definition:

This tree canopy change data set consists of three classes: no change, gain, and loss. No change polygons are those in which the tree canopy remained the same between the two time periods. Gain polygons are those in which tree canopy increased between the two time periods. Loss polygons are those in which tree canopy decrease between the two time periods. 2010 tree canopy can be calculated by adding the “no change” and loss classes. Tree canopy for 2015 can be calculated by adding the “no change” and “gain” classes.

Attribute_Definition_Source:

Project

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value:1

Enumerated_Domain_Value_Definition:

No Change

Enumerated_Domain_Value_Definition_Source:

Project

Enumerated_Domain:

Enumerated_Domain_Value:2

Enumerated_Domain_Value_Definition:

Gain

Enumerated_Domain_Value_Definition_Source:

Project

Enumerated_Domain:

Enumerated_Domain_Value:3

Enumerated_Domain_Value_Definition:

Loss

Enumerated_Domain_Value_Definition_Source:

Project

Attribute:

Attribute_Label:Shape_Leng

Attribute:

Attribute_Label:Shape_Area

Attribute_Definition:

Area of feature in internal units squared.

Attribute_Definition_Source:

Esri

Attribute_Domain_Values:

Unrepresentable_Domain:

Positive real numbers that are automatically generated.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:Pennsylvania Spatial Data Access (PASDA)

Contact_Address:

Address_Type:mailing and physical address

Address:

115 Land and Water building

City:University Park

State_or_Province:Pennsylvania

Postal_Code:16802

Country:United States

Contact_Voice_Telephone:(814) 865 - 8792

Contact_Electronic_Mail_Address:pasda@psu.edu

Distribution_Liability:

The USER shall indemnify, save harmless, and, if requested, defend those parties involved with the development and distribution of this data, their officers, agents, and employees from and against any suits, claims, or actions for injury, death, or property damage arising out of the use of or any defect in the FILES or any accompanying documentation. Those parties involved with the development and distribution excluded any and all implied warranties, including warranties or merchantability and fitness for a particular purpose and makes no warranty or representation, either express or implied, with respect to the FILES or accompanying documentation, including its quality, performance, merchantability, or fitness for a particular purpose. The FILES and documentation are provided "as is" and the USER assumes the entire risk as to its quality and performance. Those parties involved with the development and distribution of this data will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the FILES or any accompanying documentation.

Metadata_Reference_Information:

Metadata_Date:20190509

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:University of Vermont

Contact_Person:Jarlath O'Neil-Dunne

Contact_Position:Director, Spatial Analysis Laboratory

Contact_Address:

Address_Type:mailing and physical

Address:

81 Carrigan Drive

City:Burlington

State_or_Province:VT

Postal_Code:05408

Country:US

Contact_Voice_Telephone:802-865-3324

Contact_Electronic_Mail_Address:joneildu@uvm.edu

Metadata_Standard_Name:FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version:FGDC-STD-001-1998

Metadata_Time_Convention:local time

Metadata_Use_Constraints:

None