Mapping Street TreeMapping Street TreeCanopy GrowthCanopy Growth

By: Dore Burry

Course: GEOG 469

Professor: Dr. Qiu

Quarter Fall 2009

Using ArcMap to Geocode Street Tree Locationsand Project Potential Canopy Growth

Presentation Overview

Methods used to Project Canopy Growth Why use GIS for projections? Summary of Data Sources Explanation of Tree Crown Growth Rates Method of Geocoding Review of Results Strengths and Weaknesses of Project

Mapping Street Tree Canopy Growth

Methods used to Project Canopy Growth

Geocoded Street Tree Data: Using actual tree planting species and location data, I attempted to geocode 3,427 street trees that were planted from 1/07-4/09 (74 species).

Assigned Tree Growth Rates: I assigned tree growth rates based on USFS data.

Attempted to Project Canopy Growth: Using the tree growth data, I projected potential canopy growth at 10, 20, 30, 40, and 50 years from tree installation (using buffers).

Mapping Street Tree Canopy Growth

Why GIS for Projecting Canopy? Tree planting projects over the last 10 years have

provided over 100,000 new Los Angeles street trees, but few have explored potential temporal changes.

To explore possibilities of using data in a manner easily understood by funders and policy makers.

Even though tree inventory software exists, most are expensive and are an “outside” source of inventory and information. A complete, centrally (municipality) controlled GIS tree inventory, linked to all other City asset databases, is possible and likely most flexible.

Mapping Street Tree Canopy Growth

Summary of Data Sources Tree species and location data: Collected from

actual data from projects from 1/07-4/09.

Tree Crown Growth Rates: Obtained from USFS studies and publications. Also compared data to reference sources.

Aerial Imagery: ESRI World Imagery Basemap (1-Meter resolution).

Other: Los Angeles Council District Map (City), CRA Project Map (CRA/LA).

Mapping Street Tree Canopy Growth

Crown Growth Rates - Background

I assigned trees that were planted, by type, into a format the USFS uses – a simple 12 category (type) grouping. Trees with similar attributes – including height and crown size are grouped together:

Mapping Street Tree Canopy Growth

Groups:BDS - Deciduous smallBDM - Deciduous mediumBDL - Deciduous largeBES, M, and L - EvergreensCES, M, and L - ConifersPES, M and L - Palms

Crown Growth Rates - Limitations

Problem 1 – The USFS data I used included 42 species applicable to California, but only 18 of those species were ones that were actually planted!

Problem 2 – Of the 42 species, approximately half are from measurements in Santa Monica, but the other half are from Modesto.

Problem 3 - No other applicable, publicly available sources of tree growth rates exist (besides educated guesses).

Calpoly Pomona’s SelecTree, for example, is not allowed by contract to provide anything more than what is on their website.

Mapping Street Tree Canopy Growth

Crown Growth Rates - Methods applied

USFS crown growth data were averagedfor each type at 10, 20, 30, 40, and50 year measurements.

The averages were applied to each treebased on type.

Mapping Street Tree Canopy Growth

Mapping Street Tree Canopy Growth

From USFS:

Average growth rate (for type BES) applied to project trees:

Tree crown growth data was added as attributes, based on the methods described, and buffers were applied.

Single symbol colors were added for each 10 year interval

Crown Growth Rates – Use of Buffers

Mapping Street Tree Canopy Growth

Geocoding – Methods and Results

Mapping Street Tree Canopy Growth

Mapping Street Tree Canopy Growth

CD8

CD9

CD10

CD4

CD13

CD1

Geocoding Results (overview)

Mapping Street Tree Canopy Growth

Geocoding Results: Council District 10

Mapping Street Tree Canopy Growth

Geocoded Locations

Mapping Street Tree Canopy Growth

Year 10 Crown Growth

Mapping Street Tree Canopy Growth

Year 20 Crown Growth

Mapping Street Tree Canopy Growth

Year 30 Crown Growth

Mapping Street Tree Canopy Growth

Year 40 Crown Growth

Mapping Street Tree Canopy Growth

Year 50 Crown Growth

Review of Results – Canopy Creation by Year

Mapping Street Tree Canopy Growth

Potential crown growth (calculated by ArcMap):

Weaknesses of Project Method

Mapping Street Tree Canopy Growth

Tree crown growth rate data was averaged by type and not specific to species.

Due to the lack of crown growth data, some measurements from Modesto were used (local source data should be used).

Geocoding used 20-foot side offset – on wide streets, some trees did not reach the parkway.

Location data needs to be derived from a dynamic central source - property data and attributes change constantly.

This method will only produce estimates without field-collected spatial data by GPS handheld, combined with the best imagery.

This project did not consider mortality. This project did not include height, more valuable if it did.

Strengths of Project Method

Mapping Street Tree Canopy Growth

It is capable of providing accurate estimations on smaller scale projects.

Could be a good visual tool for funders and decision-makers.

Its methods can easily be modeled to projects.

Provides asset inventory as well as projections.

Provides easy and accurate way to select features by area or attribute(such as new trees located within Wilshire Center/Koreatown CRAProject area).

Questions?

Mapping Street Tree Canopy Growth