Casey Trees

Data Collection and GIS Technology

Since 2001, Casey Trees has used GIS: For inventories and surveys including neighborhood analysis To share information with District and Federal Government partners, citizens, business improvement districts and other organizations For canopy analysis to set objectives for programs and strategic planning To measure success and track performance

More Info GIS: Helping Regreen Washington, DC Strategic Regreening and Open Space Planning in Washington, D.C., Using ModelBuilder Understanding Washington,DC's Urban Tree Canopy through ArcGIS Presentation by Holli Howard and Mike Alonzo, Integrating ArcGIS Server and Flex: Highlighting the Trees in Washington, DC

Data collection

Each time Casey Trees plants a tree it is recorded in a GIS database. This means that in addition to detailed information about the tree itself, we also mark its location. We have developed an inhouse tracking program using ESRI's ArcGIS software. The robust DCGIS database has all of the infrastructure in the district digitized so you can clearly see the outlines of buildings, roads, sidewalks and parks. This provides enough information for us to spatially 'plant' the tree on the mobile tablet device. Because the data is so precise we do not need the aid of a GPS system to triangulate our position.

Developing the Data Collection Tools

Using GIS for natural resources management of the District of Columbia has become standard practice in most agencies.  District-wide GIS datasets primarily created through orthophotographic interpretation already existed. These data, maintained by the Office of the Chief Technology Officer (OCTO) for the District and the Washington Area Transit Authority, provided a map base from which to start the GIS.

To collect the tree and site attributes in the field, an ESRI ArcPad® 6.0 application was developed.  This image illustrates the standard out-of-the-box toolbars provided by ESRI.

Figure 1

Buttons were designed and added to the stripped-down toolbar to give the resulting inventory toolbar, shown here.  The tools added, from right to left, are:

• “Add tree/site” tool
• “Invalid tree/site” tool
• “Toggle ortho/vector” tool

 

 

Figure 3

Another attractive feature of ArcPad® 6.0 is the ability to create custom attribute entry forms and validation rules for attribute entry (Figure 4C).    Many types of attribute entry controls are available for ArcPad forms.  Free-form text boxes, drop-down list boxes and sliders for numeric entry were used in this inventory project.  In 2006 we will be using similar technology however we have upgraded to using tablet PCs in the field instead of the iPaq computers to enable more battery life, memory and screen space.  Figure 4C shows an example of our Big Tree Inventory Form for the 2006 inventory.

       

Figure 4A                                                      Figure 4B

Figure 4C

Figure 4A:  Clipped collection area where brown points indicate trees ‘To Be Collected’

Figure 4B: Green points represent trees that have been “Collected”

Figure 4C: Big Tree Inventory Collection Method on the larger screen Tablet PC