Abstract of the presentation:
The phenomenon of an urban heat island is entirely anthropogenic.
Approximately 50% of rise in near surface temperature is attributed to
land use change. Several decades of research recommend basically three
strategies to mitigate urban heat island: increasing reflectivity of
roofs and paving and the addition of trees. This presentation will cover
how urban heat island is measured, the basic strategies of mitigation and
focus on the strategy of planting trees in cities. When street trees are
managed as a city asset, much like other infrastructure elements such as
roadway paving, street lights, street signs, and sidewalks, both
management and value can be better integrated into budget development.
Trees are one the few public assets that appreciate with time.
City of Tucson is an example of how a street tree inventory can be
utilized to better manage this public asset. The U.S. Forest Service,
Center for Urban Forest Research developed the i-Tree suite of software to
assist in the management of urban trees. STREETS is one of four software
programs within i-Tree suites where baseline inventory data can be
analyzed to provide the structural, functional and economic benefit of
street trees. Structural features include population, species, age
distribution, condition, relative performance index, stocking levels,
maintenance recommendations, maintenance requirements, land use, location,
sidewalk damage, utility conflict, and canopy cover. Functional features
include the energy benefits,
CO2 benefits, air quality (O3, NO2, PM10, SO2, VOC, BVOC), stormwater
benefits, aesthetic benefits. Economic analysis includes all benefits,
all costs, resulting in a cost-benefit analysis. This baseline analysis
is utilized to develop a management needs assessment. The management
needs assessment along with defining level of service scenarios can lead
to an implementation plan projecting resources and budget needs. Future
consequences of deferred maintenance due to inadequate resources can then
be better understood.
Long-range ecological studies conducted by multi-discipline teams are
revealing socio-environmental justice issues. Research by sociologists
such as Dr. Sharon Harlon, Arizona State University; Dr.
Kathleen Wolf, Univ. of Washington; and Dr. Frances Kuo, Univ. of
Illinois, have shown lower income neighborhoods do have higher
temperatures, greener neighborhoods do help school-aged children with
increased learning and memory and consumer willingness to spend more in
tree lined stores.
Participants of this session will better understand the connection of
urban heat island to climate change and urban form, the nexus between
urban heat island and human health and strategies to mitigate increased
urban temperatures. The session will also introduce an asset management
approach to urban forestry to connect the benefits and value of trees in
urban areas to reduce urban temperatures and contribute to both a
healthier urban environment and human health.
About Irene:
Irene is the first Urban Landscape Manager for the City of Tucson, in the
City Manager’s Office in the Office of Conservation & Sustainable
Development (OCSD). A registered landscape architect and land planner,
she worked in the private sector for over 20 years. Projects she was
involved with included public participation programs, assisting
communities to prioritize and develop their community goals, visions,
implementation strategies, land planning master and specific plans,
ordinance drafting, landscape master planning and designs. As a
practicing landscape architect, designs included public and private sector
projects.
The Urban Landscape Manager’s success in implementing programs is
education and outreach, communicating and working with various internal
city departments (i.e., Transportation, Water, Parks & Recreation,
Environmental Services, General Service, Planning & Development Services,
Housing & Community Services, Fire Dept., etc), a city appointed Landscape
Advisory Committee, City neighborhood associations, non-profit
organizations, surrounding jurisdictions and individual City Ward offices
coordinating city-wide urban landscape issues. A few recent projects
included developing water harvesting curb cut standards, planting
standards within water harvesting basins, landscape maintenance standards
along public rights-of-way, ordinance and maintenance practices for
buffelgrass, Land Use Code landscape amendments, conducting an annual
Urban Heat Island Workshop, and conducting a street tree inventory.