New DCDC Publication

Priorities in Residential Water Use: A Trade-Off Analysis

Authors

Edward Sadalla, Department of Psychology, Arizona State University
Anna Berlin, Department of Psychology, Arizona State University
Rebecca Neel, Department of Psychology, Arizona State University
Susan Ledlow, Department of Psychology, Arizona State University

Abstract

lmarquez_FreestonePark_fullA trade-off paradigm was used to examine priorities in residential water use. A total of 426 participants allocated either a small or large budget to various household water uses. A comparison of allocations across budget conditions revealed which water uses were regarded as most important, as well as the amount of water regarded as sufficient for each use. Further analyses focused on the perceived importance of outdoor water use, which accounts for the majority of the water used in residences. Data indicated that indoor uses, especially those related to health and sanitation, were consistently higher priorities for participants in this study. The finding that residents are more willing to curtail outdoor water use than indoor water use has important implications for behavior change campaigns. Individual difference variables of environmental orientation and duration of residence in the desert accounted for some of the variance in water choices.

Download the article from the Environment and Behavior at Sage Publications. Access may be limited.

New DCDC Publication

Water management decision makers’ evaluations of uncertainty in a decision support system: the case of WaterSim in the Decision Theater

Authors

Dave D. White, Decision Center for a Desert City, ASU
Amber Y. Wutich, School of Human Evolution and Social Change, ASU
Kelli L. Larson, School of Geographical Sciences and Urban Planning and the School of Sustainability, ASU
Tim Lant, U. S. Department of Health and Human Services

Abstract

DT_TimLant_296Model-based decision support systems are increasingly used to link knowledge to action for environmental decision making. How stakeholders perceive uncertainty in models and visualisations affects their perceptions of credibility, relevance and usability of these tools. This paper presents a case study of water decision makers’ evaluations of WaterSim, a dynamic water simulation model presented in an immersive decision theatre environment. Results reveal that decision makers’ understandings of uncertainty in their evaluations of decision support systems reflect both scientific and political discourse. We conclude with recommendations for design and evaluation of decision support systems that incorporate decision makers’ views.

Download the article from the Journal of Environmental Planning and Management

New DCDC Publication

Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

Published in Hydrology and Earth Systems Sciences, January 13, 2014.

Authors

Amber Wutich, School of Human Evolution and Social Change, ASU
A.C. White, School of Human Evolution and Social Change, ASU
Dave D. White, School of Community Resources and Development, ASU
Kelli L. Larson, School of Geographical Sciences and Urban Planning, ASU
Alexandra Brewis, School of Human Evolution and Social Change, ASU
Christopher Roberts, School of Human Evolution and Social Change, ASU

Abstract

Brazil_dam_DaveWhite_296In this study, we examine how development status and water scarcity shape people’s perceptions of “hard path” and “soft path” water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

Citation

Wutich, A., White, A. C., White, D. D., Larson, K. L., Brewis, A., & Roberts, C. (2014). Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions. Hydrol. Earth Syst. Sci., 18(1), 109-120. doi: 10.5194/hess-18-109-2014

Read the entire article at Hydrology and Earth Systems Sciences.

New DCDC Publication

Impact of urban form and design on mid-afternoon microclimate in Phoenix Local Climate Zones

Authors

Ariane Middel, Center for Integrated Solutions to Climate Challenges, Arizona State University
Kathrin Häb, Department of Computer Science, University of Kaiserslautern, Germany
Anthony J. Brazel, School of Geographical Sciences and Urban Planning, Arizona State University
Chris A. Martin, Science and Mathematics Faculty, School of Letters and Sciences, Arizona State University
Subhrajit Guhathakurta, Center for Geographic Information Systems, Georgia Institute of Technology

Abstract

ArianeMiddel_figureThis study investigates the impact of urban form and landscaping type on the mid-afternoon microclimate in semi-arid Phoenix, Arizona. The goal is to find effective urban form and design strategies to ameliorate temperatures during the summer months. We simulated near-ground air temperatures for typical residential neighborhoods in Phoenix using the three-dimensional microclimate model ENVI-met. The model was validated using weather observations from the North Desert Village (NDV) landscape experiment, located on the Arizona State University’s Polytechnic campus. The NDV is an ideal site to determine the model’s input parameters, since it is a controlled environment recreating three prevailing residential landscape types in the Phoenix metropolitan area (mesic, oasis, and xeric). After validation, we designed five neighborhoods with different urban forms that represent a realistic cross-section of typical residential neighborhoods in Phoenix. The scenarios follow the Local Climate Zone (LCZ) classification scheme after Stewart and Oke. We then combined the neighborhoods with three landscape designs and, using ENVI-met, simulated microclimate conditions for these neighborhoods for a typical summer day. Results were analyzed in terms of mid-afternoon air temperature distribution and variation, ventilation, surface temperatures, and shading. Findings show that advection is important for the distribution of withindesign temperatures and that spatial differences in cooling are strongly related to solar radiation and local shading patterns. In mid-afternoon, dense urban forms can create local cool islands. Our approach suggests that the LCZ concept is useful for planning and design purposes.

Citation

Ariane Middel, Kathrin Häb, Anthony J. Brazel, Chris A. Martin, Subhrajit Guhathakurta, Impact of urban form and design on mid-afternoon microclimate in Phoenix Local Climate Zones, Landscape and Urban Planning, Volume 122, February 2014, Pages 16-28, ISSN 0169-2046, http://dx.doi.org/10.1016/j.landurbplan.2013.11.004.

New DCDC Publication

Assessment of De Facto Wastewater Reuse across the U.S.: Trends between 1980 and 2008

Published

August 19, 2013 in Environmental Science and Technology, DOI: 10.1021/es402792s

Authors

Jacelyn Rice, School of Sustainable Engineering and the Built Environment and DCDC Graduate Research Assistant, ASU
Amber Wutich, School of Human Evolution and Social Change, ASU
Paul Westerhoff, School of Sustainable Engineering and the Built Environment, ASU

Abstract

DeFactoReuse_RiceWutichWesterhoffDe facto wastewater reuse is the incidental presence of treated wastewater in a water supply source. In 1980 the EPA identified drinking water treatment plants (DWTPs) impacted by upstream wastewater treatment plant (WWTP) discharges and found the top 25 most impacted DWTPs contained between 2% and 16% wastewater discharges from upstream locations (i.e., de facto reuse) under average streamflow conditions. This study is the first to provide an update to the 1980 EPA analysis. An ArcGIS model of DWTPs and WWTPs across the U.S. was created to quantify de facto reuse for the top 25 cities in the 1980 EPA study. From 1980 to 2008, de facto reuse increased for 17 of the 25 DWTPs, as municipal flows upstream of the sites increased by 68%. Under low streamflow conditions, de facto reuse in DWTP supplies ranged from 7% to 100%, illustrating the importance of wastewater in sustainable water supplies. Case studies were performed on four cities to analyze the reasons for changes in de facto reuse over time. Three of the four sites have greater than 20% treated wastewater effluent within their drinking water source for streamflow less than the 25th percentile historic flow.

Read the entire article at Environmental Science and Technology.

New DCDC Publication

Quasi Experiments, Hedonic Models, and Estimating Trade-offs for Local Amenities

Authors

H. Allen Klaiber and V. Kerry Smith.

Journal

Land Economics, Volume 89, Number 3, August 2013

Abstract

This paper evaluates whether the property value capitalization effects measured with quasi-experimental methods offer reliable estimates of willingness to pay for changes in amenities. We propose the use of a market simulation as a robustness check. Two applications establish the method’s relevance. The first examines the conversion of land cover from desert to wet landscape. The second examines cleanup of hazardous waste sites. We find that even when quasi-experimental methods have access to ideal instruments, their performance in measuring general equilibrium willingness to pay cannot be assumed ideal. It needs to be evaluated considering the specific features of each application.

Introduction

KlaiberSmith_Figure2_296There is a fundamental distinction between estimating the effect of a policy that influences the value of a parcel on that land’s price and estimating what an individual would be willing to pay to obtain the policy. This issue is important to nearly all of the reduced form quasi-experimental (QE) and hedonic property value analyses conducted over the past decade. This distinction arises because the source of identifying information used to avoid biases in hedonic estimates that can arise from omitted variables and sorting behavior is not neutral to the economic interpretation of what is measured.1 Two approaches have been used to evaluate the empirical significance of this logical distinction in recovering estimates of economic trade-offs associated with a change in a nonmarket service. The first uses analytical models to describe the properties of these trade-off estimates, using the evaluation logic often associated with quasi experiments.2 The second approach uses simulation methods to evaluate the quantitative importance of distinguishing specific types of changes in site-specific amenities and [End Page 413] compares the evaluation logic to conventional cross-sectional hedonic methods.

The theoretical analysis by Kuminoff and Pope (2012) is an example of the first strategy. They adapt the Tinbergen-and-Jan-1959Tinbergen (1959)-Epple (1987) description of the features of a hedonic price function to describe a hedonic equilibrium. With this model they demonstrate that for an infinitesimal, exogenous change in a spatial attribute, conveyed with a house, the prechange and postchange marginal willingness to pay (MWTP) measures will be equal and correspond to the incremental price capitalization. However, in other situations the price differential associated with capitalization may not correspond to either the prechange or the postchange MWTP. In evaluating policies that are inherently nonmarginal, the close relationship between capitalization and willingness to pay (WTP) may not hold. In the current paper, we use simulation methods originating in the logic developed by Cropper, Deck, and McConnell (1988) and Kuminoff, Parameter, and Pope (2010) to provide a strategy for developing an understanding of this relationship as it arises in each specific type of application. An economic model, calibrated to a specific market, is used to simulate different hedonic equilibria and then to evaluate the performance of conventional cross-sectional hedonic models and methods based on the logic of program evaluation for estimating specific trade-offs people would make in response to changes in spatially varying amenities.

Our analysis complements the existing hedonic simulation papers and extends them to demonstrate how a market simulation can serve as a robustness check on the maintained assumptions of the evaluation logic when it is used to develop measures in property value applications of the trade-offs a person would make to secure more of a desirable amenity. For small changes, analysts have interpreted these measures as point estimates of the MWTP. For large, discrete changes associated with some applications of the evaluation framework, the appropriate interpretation of these measures is a topic of debate. Our analysis provides additional guidance on the interpretation of these measures. We focus on situations where the measure of interest is the general equilibrium willingness to pay (GE WTP) for changes in amenities, which is often the goal of policy analysis. We present two examples to illustrate the importance of a simulation check. Our findings in these examples imply that quasi experiments that are routinely a part of the evaluation logic can have large errors when their estimates of price capitalization are treated as estimates of WTP. We also find that the use of instruments with cross-sectional hedonic modeling can improve the quality of the estimates for the WTP for discrete changes in amenities. This is true even when the changes are large enough to induce re-sorting and result in a new hedonic price function. Finally, we find that the context for each application matters, so that general conclusions about robust strategies for estimating GE WTP do not follow; and therefore, it would be prudent to consider the use of similar simulations as a complement to empirical research on a case-by-case basis.

Continue reading the article at Land Economics. Subscription may be required.

Framing Water Sustainability in an Environmental Decision Support System

Author

Dave D. White
Co-director, Decision Center for a Desert City
Associate Professor, School of Community Resources and Development
Senior Sustainability Scientist, Global Institute of Sustainability
Arizona State University

Publication

Society and Natural Resources published online on June 14, 2013.

Abstract

This case study applies the theoretical concepts of frame and framing processes to identify and describe the diagnostic and prognostic frames for water sustainability expressed through an environmental decision support system. The research examines the development of WaterSim, a computer simulation model of water supply and demand in central Arizona. Qualitative data were generated through semistructured individual and group interviews, participant observations, and document analysis. The analysis identified a diagnostic frame defining the water sustainability problem as uncertain and long-term water supply shortage caused by prolonged drought, climate change impacts, and population growth. The prognostic frame for water sustainability defined the solutions to be urban residential water demand management, retirement of agricultural lands, and conversion of agricultural water to municipal uses to achieve safe yield of groundwater. The results of the study are discussed in terms of implications for decision support systems (DSS) design.

Limits to Flood Forecasting in the Colorado Front Range

Title

Limits to Flood Forecasting in the Colorado Front Range for Two Summer Convection Periods using Radar Nowcasting and a Distributed Hydrologic Model

Authors

Hernan A. Moreno, (1),(2)
Enrique R. Vivoni, (1),(3)
David J. Gochis, (4)

Publication

Journal of Hydrometeorology 2013 ; e-View
doi: http://dx.doi.org/10.1175/JHM-D-12-0129.1

Abstract

Figure 10. Spatial distribution of total (a) rainfall and (b) runoff at LTHOM during Storm 2004, 2 using QPE forcing; mean ensemble difference of precipitation for (c) 60-min and (e) 180-min 3 lead times; and mean ensemble differences of runoff for (d) 60-min and (f) 180-min lead times.

Figure 10. Spatial distribution of total (a) rainfall and (b) runoff at LTHOM during Storm 2004,
2 using QPE forcing; mean ensemble difference of precipitation for (c) 60-min and (e) 180-min
3 lead times; and mean ensemble differences of runoff for (d) 60-min and (f) 180-min lead times.

Flood forecasting in mountain basins remains a challenge given the difficulty in accurately predicting rainfall and in representing hydrologic processes in complex terrain. This study identifies flood predictability patterns in mountain areas using quantitative precipitation forecasts for two summer events from radar nowcasting and a distributed hydrologic model. We focus on eleven mountain watersheds in the Colorado Front Range (CFR) for two warm-season convective periods in 2004 and 2006. The effects of rainfall distribution, forecast lead time and basin area on flood forecasting skill are quantified by means of regional verification of precipitation fields and analyses of the integrated and distributed basin responses. We postulate that rainfall and watershed characteristics are responsible for patterns that determine flood predictability at different catchment scales. Coupled simulations reveal that the largest decrease in precipitation forecast skill occurs between 15 and 45-min lead times that coincide with rapid development and movements of convective systems. Consistent with this, flood forecasting skill decreases with nowcasting lead time, but the functional relation depends on the interactions between watershed properties and rainfall characteristics. Across the majority of the basins, flood forecasting skill is reduced noticeably for nowcasting lead times greater than 30-min. We identified that intermediate basin areas (~2 to 20 km2) exhibit the largest flood forecast errors with the largest differences across nowcasting ensemble members. The typical size of summer convective storms is found to coincide well with these maximum errors, while basin properties dictate the shape of the scale dependency of flood predictability for different lead times.

Read more here.

(1) School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287
(2) Decision Center for a Desert City, Global Institute of Sustainability, Arizona State University, Tempe, AZ 85287
(3) School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287
(4) National Center for Atmospheric Research, Boulder, CO

Historical threshold temperatures for Phoenix (urban) and Gila Bend (desert), central Arizona, USA

Climate Research, Vol 55, No. 3
January 10, 2013

Authors

D. Ruddell [1], D. Hoffman [2], O. Ahmad [3], A. Brazel [4]

Abstract

Several critically important temperature thresholds are experienced in the climate of the desert southwest USA and in central Arizona. These thresholds present significant and increasing challenges to social systems. Utilizing daily surface air temperature records from Phoenix and Gila Bend regional weather stations from 1900−2007, we examined 3 temperature thresholds: (1) frost days (minimum temperature < 0°C); (2) misery days (maximum temperature ≥43.3°C); and (3) local characteristics of heat waves. We investigated historic climate patterns in addition to considering the human implications associated with these changes. Analyses also integrated multidecadal modes of the El Niño−Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). Key findings of this study were: (1) uneven warming trends among temperature thresholds between the Phoenix (pronounced warming) and Gila Bend (modest warming) weather stations; (2) disjointed associations between ENSO and PDO with frost and misery days, signaling anthropogenic interference between temperature thresholds and historic atmospheric processes; (3) variable effects of ENSO and PDO modulations on annual frost and misery days; (4) evidence of urbanization suppressing local effects of global climate systems (i.e. ENSO, PDO); and (5) potentially significant and widespread adverse impacts on many local environmental, economic, and social systems as a result of changes in threshold temperatures.

Key Words

Temperature thresholds, Urban heat island, Phoenix, Gila Bend, Coupled natural-human systems

[1] Spatial Sciences Institute, University of Southern California, Los Angeles, California 90089-0374, USA
[2] School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan 48109-1041, USA
[3] School of Sustainability, Arizona State University, Tempe, Arizona 85287-5502, USA
[4] School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, Arizona 85287-5302, USA

A comprehensive sustainability appraisal of water governance in Phoenix, AZ

Authors: Kelli L. Larson (a,b), Arnim Wiek (a), Lauren Withycombe Keeler (a)
Journal of Environmental Management
Volume 116, 15 February 2013, Pages 58–71

Abstract

SaguaroLake_FourPeaks_296x200In Phoenix, Arizona and other metropolitan areas, water governance challenges include variable climate conditions, growing demands, and continued groundwater overdraft. Based on an actor-oriented examination of who does what with water and why, along with how people interact with hydro-ecological systems and man-made infrastructure, we present a sustainability appraisal of water governance for the Phoenix region.

Broadly applicable to other areas, our systems approach to sustainable water governance overcomes prevailing limitations to research and management by: employing a comprehensive and integrative perspective on water systems; highlighting the activities, intentions, and rules that govern various actors, along with the values and goals driving decisions; and, establishing a holistic set of principles for social–ecological system integrity and interconnectivity, resource efficiency and maintenance, livelihood sufficiency and opportunity, civility and democratic governance, intra- and inter-generational equity, and finally, precaution and adaptive capacity.

This study also contributes to reforming and innovating governance regimes by illuminating how these principles are being met, or not, in the study area. What is most needed in metropolitan Phoenix is enhanced attention to ecosystem functions and resource maintenance as well as social equity and public engagement in water governance.

Overall, key recommendations entail: addressing interconnections across hydrologic units and sub-systems (e.g., land and water), increasing decentralized initiatives for multiple purposes (e.g., ecological and societal benefits of green infrastructure), incorporating justice goals into decisions (e.g., fair allocations and involvement), and building capacity through collaborations and social learning with diverse interests (e.g., scientists, policymakers, and the broader public).

Continue to the full text of the article at Science Direct.

(a) School of Sustainability, Arizona State University, Mail Code 5502 Tempe, AZ 85287-5502, USA
(b) School of Geographical Sciences and Urban Planning, Arizona State University, Mail Code 5302 Tempe, AZ 85287-5302, USA