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The Desert Southwest: Oasis or Mirage?

May 10, 2012

by Pete Zrioka, Arizona State University Office of Knowledge Enterprise Development

The American West has a drinking problem. On farms and in cities, we are guzzling water at an alarming rate.

Scientists say that to live sustainably, we should use no more than 40 percent of the water from the Colorado River Basin. As it is now, we use 76 percent, nearly double the sustainable benchmark.

There are some safeguards in place against water scarcity. The reservoir Lakes Mead and Powell can provide approximately five years of average annual stream flow at full capacity for insurance against low rainfall years.

But John Sabo, an associate professor in Arizona State University’s School of Life Sciences, believes that 50 years in the future – rather than five – should be the planning mark for water usage.

David White, co-director of ASU’s Decision Center for a Desert City (DCDC), says that Arizona water policy has done a good job of providing adequate supplies for the growth of the region up to this point. But environmental and demographic factors will likely require changes in that system. The DCDC uses research to inform environmental policy in times of uncertainty.

Read the entire article at ASU News.

DCDC Poster Symposium

May 1, 2012

On April 25, 2012, Decision Center for a Desert City hosted their annual poster symposium. A highlight of the spring semester, graduate students enrolled in the Community of Graduate Scholars and undergraduate students participating in the Internship for Science-Practice Integration program presented the results of their DCDC research projects.

Community of Graduate Scholars (CGS)

The Community of Graduate Scholars is a year-long, one-credit course that gives graduate students the opportunity to become leaders in transdisciplinary approaches to research, policy, and community engagement.

(L to R) Becca Neel, Gretchen Hawkins, Geetali Dudhbhate, Chrissie Bausch
Students work on Decision Center for a Desert City projects, as well as related efforts at ASU. Students are involved in multiple projects, examining the relationships among them, and thus learn to articulate and promote integrated perspectives.

DCDC faculty members are involved in interdisciplinary collaborations that offer rich opportunities to graduate students. Each CGS student works on a research team that includes one or more faculty members and both graduate and undergraduate students; this work provides them with the intellectual depth necessary to contribute to DCDC’s research.

CGS provides graduate students with a supportive environment where they can:

  • develop a broad understanding of the research process and how it is practiced across sciences
  • develop a professional and unique intellectual identity and voice
  • improve scientific communication and presentation skills
  • engage with researchers and community partners
  • make contributions to DCDC as a boundary organization


  • Envisioning Water Futures in the Greater Phoenix Area: What Do We Want The Future To Look Like? - Lauren Withycombe Keeler (CGS), Arnim Wiek, Dave White, Kelli Larson, and Kendon Jung
  • Psychological Barriers to Water Conservation: The Case of Desert Landscaping - Rebecca Neel (CGS), Edward Sadalla, Susan Ledlow, Anna Berlin, Samantha Neufeld, Yexin Li, and Claire Yee
  • Half Full? Buffering Central Arizona Farmers from Signals of Environmental Change - Julia C. Bausch (CGS), John P. Conners, and Hallie Eakin
  • Distributed Hydrologic Modeling of Semiarid Basins in Arizona: A Platform for Climate Change Assessments - Gretchen A. Hawkins (CGS) and Enrique R. Vivoni
  • A Decision Making Game to Guide Water Sustainability Related to Policy Outcomes - Geetali Dudhbhate (CGS), Erik Johnston, Ajay Vinze, Rashmi Krishnamurthy, Dweepika Desai, and Qian Hu
  • Interactive Computer Simulations for Public Administration Education - Rashmi Krishnamurthy, Qian Hu, and Erik Johnston

Internship for Science-Practice Integration

The Decision Center for a Desert City undergraduate internship program bridges the world of academia to the world of water management by placing students with agencies to carry out use-inspired research projects.

(L to R) Katja Brundiers, Michael Babcock, Michael Nicastro, Colin Russell, McKenzie Ragan, Kena Fedorschak, Ariel Pepper, Dr. Peggy Nelson
Through the program, students learn about the concepts and practical aspects of boundary research. The one-semester internship program is available to undergraduate students in their senior year.

The DCDC internship program integrates science and practice by expecting the students:

  • to work 10 hours per week on a project that is relevant to their internship mentor and agency, learning about professional practice
  • to develop an original research project within the internship , linking science and practice
  • to team-up with a faculty mentor, receiving academic advice and ensuring the academic rigor of their research project
  • to participate in a weekly 3-credit hour class to discuss the research-based internship, building skills in the areas of communication, meeting facilitation, and presentation delivery


State-level ADWR (general governance approaches)

How Do We Catalyze Adaptive and Innovative Practices in Public Regulatory Agencies?

  • McKenzie Ragan, Internship Fellow, School of Sustainability
  • Michael J. Lacey, Internship Provider, Arizona Department of Water Resources
  • Dave D. White, Faculty Mentor, Decision Center for a Desert City

Inter-city comparison: Planning approach 1: scenario construction as adaptive planning approach

How Scenario Planning Will Benefit Scottsdale Water Resources’ Master Planning Process

  • Ariel Pepper, Internship Fellow, School of Sustainability
  • Beth Miller, Internship Provider, City of Scottsdale
  • Ray Quay, Faculty Mentor, Decision Center for a Desert City

Inter-City level: Planning approach 2: collaborative management: problem perception and potential solution-options

Prevalent Perceptions of Water Use in Arizona

  • Colin Russell, Internship Fellow, School of Sustainability
  • Mark Holmes, Internship Provider, City of Mesa
  • Erik Johnston, Faculty Mentor, School of Public Affairs

What Factors Motivated the Creation of the Colorado and Kansas Water Congresses?

  • Kena Fedorschak, Internship Fellow, School of Sustainability
  • Mark Holmes, Internship Provider, City of Mesa
  • Erik Johnston, Faculty Mentor, School of Public Affairs

Engaging businesses as multiplier of solutions

The Relationship between Restaurants and Sustainability: Marketing the Tempe FOG Program

  • Michael Nicastro, Internship Fellow, School of Sustainability
  • David McNeil, Internship Provider, City of Tempe
  • George Basile, Faculty Mentor, School of Sustainability

Smartscape: Using Education as a Tool for Reducing Water in Desert Landscapes

  • Michael Alan Babcock, Internship Fellow, School of Sustainability
  • Summer Waters and Haley Paul, Internship Provider, University of Arizona Cooperative Extension
  • Kelli Larson, Faculty Mentor, School of Geographical Sciences and Urban Planning and the School of Sustainability

Analysis of Arizona's Water Resources System

April 30, 2012

Author: Jesus R. Gastelum, Central Arizona Project

ABSTRACT An analysis of Arizona’s water resources system has been implemented. This study uses a qualitative system analysis approach to evaluate the most important components of the system: water supply, water demand, laws and regulations, stakeholders, decision makers, etc. Moreover, the investigation centres on some key components of the water resources system such as water conservation in active management areas (AMA), rural Arizona, population growth, and water rights transfers. This study provides insights on these important components, identifies factors that can be enhanced and offers suggestions for improving them. The overall goal of this analysis is to contribute ideas that will help to establish a more efficient and holistic programme to secure sustainable development of water resources.

For the full article.

Urban Heat Island Research in Phoenix

April 27, 2012

Urban Heat Island Research in Phoenix, Arizona: Theoretical Contributions and Policy Applications

Authors: Winston T. L. Chow, Dean Brennan, and Anthony J. Brazel

Department of Engineering, Arizona State University, Mesa, Arizona

School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, Arizona


Over the past 60 years, metropolitan Phoenix, Arizona, has been among the fastest-growing urban areas in the United States, and this rapid urbanization has resulted in an urban heat island (UHI) of substantial size and intensity. During this time, an uncommon amount of UHI-specific research, relative to other cities in North America, occurred within its boundaries. This review investigates the possible reasons and motivations underpinning the large body of work, as well as summarizing specific themes, approaches, and theoretical contributions arising from such study. It is argued that several factors intrinsic to Phoenix were responsible for the prodigious output: strong applied urban climate research partnerships between several agencies (such as the academy, the National Weather Service, private energy firms, and municipal governments); a high-quality, long-standing network of urban meteorological stations allowing for relatively fine spatial resolution of near-surface temperature data; and a high level of public and media interest in the UHI. Three major research themes can be discerned: 1) theoretical contributions from documenting, modeling, and analyzing the physical characteristics of the UHI; 2) interdisciplinary investigation into its biophysical and social consequences; and 3) assessment and evaluation of several UHI mitigation techniques. Also examined herein is the successful implementation of sustainable urban climate policies within the metropolitan area. The authors note the importance of understanding and applying local research results during the policy formation process.

Chow, Winston T. L., Dean Brennan, Anthony J. Brazel, 2012: Urban Heat Island Research in Phoenix, Arizona: Theoretical Contributions and Policy Applications. Bull. Amer. Meteor. Soc., 93, 517–530.


Our Future with Water: Three-part Film Series

April 27, 2012

Friday, May 4, 11 and 18, 7 p.m.

Water conservation is an important lesson to learn when living in the desert. The Tempe History Museum will host a three-part film series on what will happen to the future of water. Join the museum to enjoy these documentaries:

Blue Gold: World Water Wars. A film that reports on various powers trying to take control of the public’s water for personal profit. (Friday, May 4)

Tapped. A film examining the role of the bottled water industry (Friday, May 11)

The American Southwest: Are we running dry? A definitive look at how the water crisis affects the American Southwest (Friday, May 18)

Expert presenters will host each session with introductory remarks, the film screening and a question and answer period. Refreshments (including water) will be served.

In the News

April 24, 2012

San Diego Takes Water Fight Public: Fees and Anger Rise in California Water War

by Adam Nagourney and Felicity Barringer at The New York times

There are accusations of conspiracies, illegal secret meetings and double-dealing. Embarrassing documents and e-mails have been posted on an official Web site emblazoned with the words "Fact vs. Fiction." Animosities have grown so deep that the players have resorted to exchanging lengthy, caustic letters, packed with charges of lying and distortion.

And it is all about water.

Water is a perennial source of conflict and anxiety throughout the arid West, but it has a particular resonance here in the deserts of Southern California.

Read the article at The New York Times.

In the News

April 10, 2012

April 2012 The Morrison Institute launches a new series about Arizona's water future. The first in the series "Let's Talk Water" by Grady Gammage, is intended to prompt discussion about our state's essential resource.

April 12, 2012 DCDC researcher Ray Quay, co-authored Opening Access to Scenario Planning Tools. In the face of increasing complexity and uncertainty, planners, public officials, and community residents need new tools to anticipate and shape the future. Opening Access to Scenario Planning Tools examines the current state of scenario planning and scenario planning tools that can help communities and regions prepare for that future through a variety of visioning, land use, transportation, and other planning efforts. Download the report.

April 12, 2012 Chicago Climate Action Plan a One NOAA Science Seminar Series. Abstract: Urban areas are responsible for 70% of global greenhouse gas emissions and cities are increasingly seen as the place where the solutions to climate change will be found. Chicago developed its Climate Action Plan in 2007 to outline the mitigation and climate readiness goals for the city. It has since been recognized as one of the leading plans in the country because of its scientific rigor, community involvement, and actionable targets.

April 10, 2012 Dot Earth: More on Extreme Weather in a Warming Climate via Andrew Revkin at The New York Times.

April 10, 2012 A Visualization of March Heat Breaking 15,000 Records in the U.S. via The Atlantic.

April 9, 2012 Volunteers Clean Up Tempe's 'A' Mountain via AZ Central.

March 22, 2012 Intelligence Community Assessment (ICA) on Global Water Security. The ICA is based on a National Intelligence Estimate requested by Secretary Clinton to assess the impact of global water issues on U.S. national security interests. The report concludes that while wars over water are unlikely within the next ten years, water challenges – shortages, poor water quality, floods - will likely increase the risk of instability and state failure, exacerbate regional tensions, and distract countries from working with the United States on important policy objectives. Read the report.

April 17 Water/Climate Briefing

April 6, 2012

The Economics of Water Demand: The Dynamics of Water Use and Price


V. Kerry Smith, Regents Professor, W. P. Carey School of Business, Department of Economics

Doug Frost, Principal Planner, Water Services Department, City of Phoenix

Gary Niekerk, Director of Corporate Citizenship, Intel Corporation

When and Where:

Tuesday, April 17, 2012, 12:00-1:30pm

Decision Center for a Desert City

21 East 6th Street, Suite 126B, Tempe

Map: /dcdc/about-us/contact/

Lunch will be served. Please RSVP to


Price is often suggested as a simple straightforward tool to encourage people to be more efficient in how they use water. However, the economics of water demand are not that simple. Water is used for many purposes. Water is used to meet the basic necessity of life, consumption and hygiene. Water is used to create an atmosphere that suits our lifestyles, landscapes and pools, and perhaps long hot showers. Water is used for economic gain, from creating places attractive to customers to washing silicon chips. The sale of water is also used to finance the infrastructure and costs associated with making water available to a community. Each of these water uses has its own economic dynamics based on behaviors and motivation for water use which can vary among the consumers in each category. At the same time, the economics for each of these water uses are related, changes in one can affect the other. Thus, decision making about the price of water is not as clear as it may initially appear. The goal of this climate briefing is to increase the awareness of the complexities associated with the price of water by facilitating a discussion about the differences and relationships that exist in the economics of different water uses.

Download the flyer.

Arizona Climate and Water Resources Alliance Workshop

April 4, 2012

On April 4, 2012, Decision Center for a Desert City hosted the Arizona Climate and Water Resources Alliance Collaborative Workshop on Climate Extremes exploring extreme climate events and their regional implications for water management: floods and droughts. The purpose of this workshop was to build on research in atmospheric science, hydrology, and climate assessment performed by scientists at the University of Arizona, Arizona State University, and other partner institutions, in order to address issues related to extreme hydroclimatic events (e.g. droughts, floods), and to plan a larger meeting to discuss extreme events and their implication for flood and drought management with scientists and flood and water managers.

The goals of this informal meeting:

  1. Foster dialogue among researchers and floodplain and water resources managers.
  2. Share the concerns of water professionals: What kind of dcisions do flood and water managers make? What data and information (e.g., resolution, lead time) needs exist among flood and water managers (given the current state of research)?
  3. Share the state of the science: present, assess, and discuss the scientific progress around projecting extreme events and assessing their implications on a regional level (flood as short-term extreme event, drought as long-term extreme event).
  4. Present a strategy for moving forward on science and planning for extreme events outside of the range of historical record: The ARkStorm project, in which scientists regional engineers, emergency managers, economists, and others collaborated to combine historic floods in a scientifically plausible way, in order to examine engineering and emergency management solutions that are fiscally sound and responsible. On the dry side: a "Joseph's Drought" project.
  5. Gain consensus on a short-term research strategy to address extreme events in Arizona, and identify elements needed for a long-term research strategy.
  6. Identify participants for larger meeting.

Southwest Climate Assessment Report Review

April 4, 2012

The Southwest Climate Alliance [SWCA] welcomes your comments on a DRAFT version of the "Assessment of Climate Change in the Southwest United States: A Technical Report Prepared for the U.S. National Climate Assessment".

The SWCA is a consortium of research institutions in the region, including NOAA Regional Integrated Sciences and Assessments (The Climate Assessment for the Southwest [CLIMAS], The California-Nevada Applications Program [CNAP], and the Western Water Assessment [WWA]) and the U.S. Department of Interior's Southwest Climate Science Center.

Written chiefly during late 2011, with revisions in early 2012, this report provides a snapshot of the current state of climate change information and knowledge related to the U.S. Southwest region. The region covers six states—Arizona, California, Colorado, Nevada, New Mexico, and Utah—an area that includes vast stretches of coastline, an international border, and the jurisdictions of nearly two hundred Native Nations.

Visit the Southwest Climate Assessment Report Review website.

NSF Leads Federal Efforts In Big Data

March 30, 2012

At a White House event, the NSF Director announced a new Big Data solicitation, $10 million Expeditions in Computing award, and awards in cyberinfrastructure, geosciences, training.

Researchers in a growing number of fields are generating extremely large and complicated data sets, commonly referred to as "big data." A wealth of information may be found within these sets, with enormous potential to shed light on some of the toughest and most pressing challenges facing the nation. To capitalize on this unprecedented opportunity--to extract insights, discover new patterns and make new connections across disciplines--we need better tools to access, store, search, visualize and analyze these data.

Read more at the National Science Foundation website.

DCDC Google Scholar Page

March 30, 2012

We've created a Google Scholar page for Decision Center for a Desert City publications. Google Scholar provides a review of Decision Center for a Desert City literature across many disciplines and sources, including theses, books, abstracts and articles. Google Scholar aims to rank documents the way researchers do, weighing the full text of each document, where it was published, who it was written by, as well as how often and how recently it has been cited in other scholarly literature.

You'll also find Google Scholar pages for DCDC researchers which provides a simple way for authors to keep track of citations to their articles. You can check who is citing your publications, graph citations over time, and compute several citation metrics. You can also make your profile public, so that it may appear in Google Scholar results.

Visit the Decision Center for a Desert City Google Scholar page.

Spatial Optimization Models for Water Supply Allocation

March 21, 2012

Authors: Alan T. Murray (1), Patricia Gober (2, 3), Luc Anselin (1), Sergio J. Rey (1), David Sampson (3), Paul D. Padegimas (1), Yin Liu (1)

in Water Resource Management, DOI 10.1007/s11269-012-0013-5


Fig. 1 Water sources by large providers in metropolitan Phoenix
Climate change is likely to result in increased aridity, lower runoff, and declining water supplies for the cities of the Southwestern United States, including Phoenix. The situation in Phoenix is particularly complicated by the large number of water providers, each with its own supply portfolio, demand conditions, and conservation strategies. This paper details spatial optimization models to support water supply allocation between service provider districts, where some districts experience deficits and others experience surpluses in certain years. The approach seeks to reconcile and integrate projections derived from a complex simulation model taking into account current and future climate conditions. The formulated and applied models are designed to help better understand the expected increasingly complex interactions of providers under conditions of climate change. Preliminary results show cooperative agreements would reduce spot shortages that would occur even without climate change. In addition, they would substantially reduce deficits if climate change were to moderately reduce river flows in Phoenix’s major source regions, but have little effect under the most pessimistic scenarios because there are few surpluses available for re-allocation.


The results obtained from the developed spatial optimization model reflecting regional cooperation in water supply management across the Phoenix metropolitan area demonstrate the insights possible from a modeling based analysis approach. It is foreseeable that the introduction of demand management strategies will be necessary in the face of future climate change, but also it is possible to significantly reduce deficits in some cases. By taking full advantage of all the water that is available as well as establishing cooperation between water districts, as opposed to the practice of conserving surpluses for future use but not distributing extra water when available to those districts in need, it is possible to stretch the available supply of water to ensure that the impacts of water shortages are minimized.

In every scenario, the results pointed to clear benefits of regional cooperation, whether it is the complete avoidance of deficits over a period of time (Scenarios 1 and 2), to a reduction of total deficits across the region (Scenarios 3 and 4). Effective policy implementation could lead to the employment of a trading strategy that embodies the benefits demonstrated in this paper. It is clear in each scenario presented in this paper that Phoenix and its ability to transfer water either in from or out to other districts appears inevitable. As the largest city in the region by almost four times, it will clearly be an important factor in water resource management. While it is assumed in this paper that water transfers are possible by simply recharging subsurface aquifers by one district and pumping out water by another, there may be a need for conveyance infrastructure to successfully implement an effective water sharing strategy in the region. Whether it be by manmade infrastructure or natural aquifers, in the case of the Phoenix metropolitan region, it is obvious that the city of Phoenix must be completely intertwined with the water network of the region.

The linear program presented in this paper is a foundation for effective water management and is, in the form presented, adaptable to accommodate different weighting schemes. While it may be possible to re-allocate water across the region in a more equitable manner than weighting by population of each provider district, it is evident that as it stands, this model is effective for demonstrating the potential gains of any region with multiple, independent water providers, through optimal water re-allocation. The potential to change the weighting mechanism will be important for future work, which may include a cost structure for transfer transactions, measures of social benefit achieved by water re-allocation, or economic gains related to water availability. Decision rules about who does and does not share access to relevant conveyance infrastructure may also be included in future applications. While different potential decision rules and weighting mechanisms will likely vary by application, the foundation for multi-district water re-allocation modeling presented here clearly demonstrates the potential benefits of such a system.


This article is based on work supported by the National Science Foundation under Grant No. SES-0345945, Decision Center for a Desert City. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

(1) GeoDa Center for Geospatial Analysis and Computation, School of Geographical Sciences and Urban Planning, Arizona State University

(2) School of Geographical Sciences and Urban Planning, Arizona State University

(3) Decision Center for a Desert City, Arizona State University

Observatories for Integrated Water Basin Science

March 21, 2012

An Eos FORUM article by L. Douglas James, via Eos, Vol. 93, No. 10, 6 March 2012.

For more than 30 years, with the last 20 years at the U.S. National Science Foundation (NSF), I have been immersed in community efforts to focus water resources research on growing societal needs. Past strategies have stumbled, but creative thinking on basin function offers a way out. The following ideas are mine and are not necessarily shared by NSF. Read more here: Eos, Vol. 93, No. 10, 6 March 2012.

In the News

March 7, 2012

  • Winter precipitation levels were dryer than normal in West & Southeast via NOAA.
  • The first big thing to hit Phoenix since light rail via PURL.
  • Arizona GOP Lawmakers Want Control of Energy Policy via AZCentral.
  • WRRC Interview with Tom Buschatzke, via Arizona Water Resource.
  • Metropolitan Water Policy in the Wet and Dry Sunbelt, video of Robert Lange, WRRC Keynote Speaker via WRRC.
  • Farmers and Conservationists Working Together in the Colorado River Basin via National Geographic NewsWatch.
  • NASA What Doesn't Stay in Vegas: Sprawl via NASA Explorer.

In the News

March 1, 2012

Math and Climate Research Network Workshop

March 1, 2012

ASU Professors Alex Mahalov and Eric Kostelich bring their Math and Climate Research Network Workshop to DCDC on March 5-7, 2012. The Math and Climate Research Network links researchers across the US to develop the mathematics needed to better understand the Earth's climate.

It is generally accepted in the scientific community that the world is undergoing a significant change in its climate. The issues and problems of the science that seeks to understand the earth's climate, and how it is changing, have a significant mathematical dimension. The Mathematics and Climate Research Network (MCRN) is a virtual organization of leading researchers in mathematics and geosciences whose mission is to establish a new area of applied mathematics tailored to the needs of climate research.

The network consists of researchers at "nodes" across the US, together with several collaborating government and university labs and centers in the US and beyond. Network researchers have a collective expertise that cuts across the relevant areas of applied mathematics and climate science. They will collaboratively lead a group of postdoctoral research fellows, graduate and undergraduate students to create a cadre of strong mathematicians with the interdisciplinary expertise required to analyze problems that have their origin in climate issues.

MCRN is funded by an award from the National Science Foundation's Division of Mathematical Sciences, and is administered through the Renaissance Computing Institute.

In the News

February 22, 2012

  • Climate change takes back seat to decision-making in water security says ASU researcher Patricia Gober via ASU News.
  • Get the basics on WaterSense during the EPA's "WaterSense 101" webinar from 3-4pm EST tomorrow, Feb 23. Register here.
  • Local Phoenix Artist, Matthew Moore, going back to the "Roots" of urban development.
  • How public perception of light rail influences its economic benefits, via Atlantic Cities.
  • Tracking How the World Guzzles Water via Green-A NY Times Blog About Energy and the Environment.
  • Harness the power of green infrastructure; view EPA's newly revamped green infrastructure website.

Land cover modification scenarios

February 22, 2012

DCDC Publication

Land cover modification scenarios and their effects on daytime heating in the inner core residential neighborhoods of Phoenix, AZ, USA

Authors: Ariane Middel (1), Anthony Brazel (2), Bjoern Hagen (2), Soe Myint (2)


This study addresses simulations of summertime atmospheric heating/cooling and water use at the local scale in Phoenix, Arizona – a city in the arid Southwestern United States. Our goal is to consider various climate effects by the manipulation of land coverage within census tracts at the local scale. This scale refers to horizontal areas of approximately 102–104 m on a side and to measurement heights in the inertial sublayer above the urban canopy and its roughness sublayer. The model we use for this scale is the Local Scale Urban Meteorological Parameterization Scheme (LUMPS) after Grimmond and Oke, 2002. We calculate different scenarios using the LUMPS model to determine the interplay of water use and summer diurnal variations of atmospheric heating and cooling processes for selected census tracts in Phoenix. First, we simulate xeriscaping within the census tract neighborhoods by transforming green spaces into soil. The second scenario simulates an infill and Brownfield development scenario, increasing density and impervious surfaces while at the same time decreasing soil. Third, we reduce barren soil and impervious surface areas to simulate a green city. With LUMPS we can understand the optimization of water use and at the same time the maximization of the cooling potential within the local scale area as a whole, dependent on varying the total surface cover fractions. In urban planning, LUMPS can be used as scenario based tool to design pedestrian-friendly sustainable development in desert climates where land coverage is tailored to reduce UHI effects and to induce more comfortable daytime temperatures.

Discussion and Conclusion

Our scenario-based local-scale model approach can assist planners in making better-informed decisions on UHI mitigation strategies. The results of the scenario-based model runs indicate which urban design is best for a particular location – a challenging decision, especially in desert cities like Phoenix where water supply is crucial for a sustainable future. These findings could be used as a basis for specific policy approaches to UHI management. In 2006, the Downtown Phoenix Urban Form Project was started to shape future growth and create a more integrated, pedestrian oriented, and sustainable downtown through form-based codes (City of Phoenix, 2008). The regulating plan developed by the Urban Form Project suggests urban design principles to mitigate the UHI effect and to create a more comfortable and sustainable downtown environment. The proposed strategies are based on urban form principles regarding street and building proportion, open space, vegetation, building design, and building materials. One of the measures is the "connected oasis", a plan connecting existing and new public spaces through a green street network.

Our modeling approach complements the Urban Form Project by quantifying the optimal vegetative coverage to mitigate UHI effects and create a more comfortable pedestrian-friendly environment. Although our results may suggest recommendations for land coverage within neighborhoods to minimize water use and heating, the model cannot specify the spatial arrangement of land cover fractions. To determine the urban design within neighborhoods more precisely, a micro-scale model would have to be employed. Another application of our scenario-based model results are Climate Action Plans, a policy tool urban planners use to minimize heating. As of 2009, over 141 local jurisdictions and states have already developed Climate Action Plans to mitigate and adapt to global climate change by reducing greenhouse gas emissions and preparing for possible climate change threats and risks.

Increasingly, Climate Action Plans do not only focus on greenhouse gas emissions, but also address adaptation measurements such as UHI maps, green urban design, and water conservation. Future research may include the development of additional mitigation scenarios such as changing the mean albedo of the land cover fractions or the albedo of individual surfaces such as roof tops and impervious surfaces. To refine the densification scenario, the manipulation of average building heights would be beneficial. We also envision a greater number of variables for land cover fractions, e.g., pervious pavements, and leaf indices for trees and plants native to the Sonoran Desert. To enhance the application of the model, the integration of the model into a geographical information system (GIS) would allow for the correlation of spatial analyses of temperature variations with other relevant geodata.

1 Decision Center for a Desert City, Arizona State University, Tempe, AZ, USA

2 School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ, USA

AAAS - Scientists Offer Passionate, Innovative Ways to Engage the Public on Climate Change

February 20, 2012

The plenary session of the AAAS conference in Vancouver moderated by Frank Sesno, was held before a packed ballroom of more than 1400 participants and webcast live, was billed as a way for scientists to explore new ways of getting their messages out to the public. If science isn’t enough to convince people that warming is a real "planetary emergency," the panelists asked, what can researchers try next?

AAAS Plenary 2012 - Scientists Offer Passionate, Innovative Ways to Engage the Public on Climate Change