This paper analyzed the evolving response of daily water use to weather fluctuations over 29 year... more This paper analyzed the evolving response of daily water use to weather fluctuations over 29 years for two Portland-area municipal water providers -Portland Water Bureau (PWB), serving a dense urban area, and Tualatin Valley Water District (TVWD), serving a rapidly growing suburban area. Temperature sensitivity, the response of water use to a temperature increase, generally declined for both water providers. A downward shift in temperature sensitivity was identified for PWB in 1992, owing to outdoor water use curtailment during a water scarcity event, followed by aggressive demand management measures. No corresponding shift was detected for TVWD due to high suburban growth rates throughout the 1990s. Recent downward step changes in temperature sensitivity for both providers indicated some modicum of convergence in water use patterns, reflecting converging trends in socio-economic and land development characteristics in both areas. We argue that a confluence of historical factors, including the 1992 drought, aggressive (though uneven) demand management, changes to the building code, and ongoing densification of both urban and suburban areas, have reduced per-capita water use and attenuated the connection between water use and temperature. Softening the seasonality of water use represents an important but often-overlooked component of urban climate change adaptation.
This paper investigated the role of grocery store prices in structuring food access for low-incom... more This paper investigated the role of grocery store prices in structuring food access for low-income households in Portland, Oregon. We conducted a detailed healthful foods market basket survey and developed an index of store cost based on the USDA Thrifty Food Plan. Using this index, we estimated the difference in street-network distance between the nearest low-cost grocery store and the nearest grocery store irrespective of cost. Spatial regression of this metric in relation to income, poverty, and gentrification at the census tract scale lead to a new theory regarding food access in the urban landscape. Food deserts are sparse in Portland, but food mirages are abundant, particularly in gentrifying areas where poverty remains high. In a food mirage, grocery stores are plentiful but prices are beyond the means of low-income households, making them functionally equivalent to food deserts in that a long journey to obtain affordable, nutritious food is required in either case. Results suggested that evaluation of food environments should, at a minimum, consider both proximity and price in assessing healthy food access for low-income households.
Adaptation to climate change requires urban water providers to develop a complex understanding of... more Adaptation to climate change requires urban water providers to develop a complex understanding of how temperature affects water use patterns. We used a geographic information system and statistical analysis to compare the spatial relationships among single-family residential water use patterns, land use characteristics, and temperature in Portland, Oregon and Phoenix, Arizona. We developed mean water use patterns at the census block group level using data from 2002 to 2009 in Portland and from 2000 to 2008 in Phoenix. These mean values were used to estimate the localized temperature sensitivity of water use in each census block group through an ordinary least squares regression with summer average air temperature. Taking the slopes of regression estimates as our dependent variable, we examined spatial relationships among temperature-sensitive water use patterns, housing density, impervious surfaces, low vegetation, and tree canopy extent. Temperature sensitive water use was found to be positively correlated with low vegetation and negatively correlated with impervious surfaces in both cities. Tree canopy coverage tends to increase with sensitivity in Portland, while the reverse relationship is found for Phoenix. Regression analysis indicates that building density explained the most variation in the dependent variable in Portland whereas, in Phoenix, the strongest correlations related to vegetation patterns. A comparative approach highlights the complex, localized correlations that exist among local climate regimes, urban landscapes, and water use patterns. Census block group-level water use analyses equips water providers with detailed information on the sensitivity of local water use to temperature variation, which could prove valuable to developing a viable municipal climate change adaptation strategy.
This paper analyzed the evolving response of daily water use to weather fluctuations over 29 year... more This paper analyzed the evolving response of daily water use to weather fluctuations over 29 years for two Portland-area municipal water providers -Portland Water Bureau (PWB), serving a dense urban area, and Tualatin Valley Water District (TVWD), serving a rapidly growing suburban area. Temperature sensitivity, the response of water use to a temperature increase, generally declined for both water providers. A downward shift in temperature sensitivity was identified for PWB in 1992, owing to outdoor water use curtailment during a water scarcity event, followed by aggressive demand management measures. No corresponding shift was detected for TVWD due to high suburban growth rates throughout the 1990s. Recent downward step changes in temperature sensitivity for both providers indicated some modicum of convergence in water use patterns, reflecting converging trends in socio-economic and land development characteristics in both areas. We argue that a confluence of historical factors, including the 1992 drought, aggressive (though uneven) demand management, changes to the building code, and ongoing densification of both urban and suburban areas, have reduced per-capita water use and attenuated the connection between water use and temperature. Softening the seasonality of water use represents an important but often-overlooked component of urban climate change adaptation.
This paper investigated the role of grocery store prices in structuring food access for low-incom... more This paper investigated the role of grocery store prices in structuring food access for low-income households in Portland, Oregon. We conducted a detailed healthful foods market basket survey and developed an index of store cost based on the USDA Thrifty Food Plan. Using this index, we estimated the difference in street-network distance between the nearest low-cost grocery store and the nearest grocery store irrespective of cost. Spatial regression of this metric in relation to income, poverty, and gentrification at the census tract scale lead to a new theory regarding food access in the urban landscape. Food deserts are sparse in Portland, but food mirages are abundant, particularly in gentrifying areas where poverty remains high. In a food mirage, grocery stores are plentiful but prices are beyond the means of low-income households, making them functionally equivalent to food deserts in that a long journey to obtain affordable, nutritious food is required in either case. Results suggested that evaluation of food environments should, at a minimum, consider both proximity and price in assessing healthy food access for low-income households.
Adaptation to climate change requires urban water providers to develop a complex understanding of... more Adaptation to climate change requires urban water providers to develop a complex understanding of how temperature affects water use patterns. We used a geographic information system and statistical analysis to compare the spatial relationships among single-family residential water use patterns, land use characteristics, and temperature in Portland, Oregon and Phoenix, Arizona. We developed mean water use patterns at the census block group level using data from 2002 to 2009 in Portland and from 2000 to 2008 in Phoenix. These mean values were used to estimate the localized temperature sensitivity of water use in each census block group through an ordinary least squares regression with summer average air temperature. Taking the slopes of regression estimates as our dependent variable, we examined spatial relationships among temperature-sensitive water use patterns, housing density, impervious surfaces, low vegetation, and tree canopy extent. Temperature sensitive water use was found to be positively correlated with low vegetation and negatively correlated with impervious surfaces in both cities. Tree canopy coverage tends to increase with sensitivity in Portland, while the reverse relationship is found for Phoenix. Regression analysis indicates that building density explained the most variation in the dependent variable in Portland whereas, in Phoenix, the strongest correlations related to vegetation patterns. A comparative approach highlights the complex, localized correlations that exist among local climate regimes, urban landscapes, and water use patterns. Census block group-level water use analyses equips water providers with detailed information on the sensitivity of local water use to temperature variation, which could prove valuable to developing a viable municipal climate change adaptation strategy.
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Papers by Betsy Breyer