Maliszewski, Paul J.; Larson, Elisabeth K.; Perrings, Charles. (2012). Environmental Determinants of Unscheduled Residential Outages in the Electrical Power Distribution of Phoenix, Arizona. Reliability Engineering & System Safety, 99, 161 – 171.
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Abstract
The sustainability of power infrastructures depends on their reliability. One test of the reliability of an infrastructure is its ability to function reliably in extreme environmental conditions. Effective planning for reliable electrical systems requires knowledge of unscheduled outage sources, including environmental and social factors. Despite many studies on the vulnerability of infrastructure systems, the effect of interacting environmental and infrastructural conditions on the reliability of urban residential power distribution remains an understudied problem. We model electric interruptions using outage data between the years of 2002 and 2005 across Phoenix, Arizona. Consistent with perceptions of increased exposure, overhead power lines positively correlate with unscheduled outages indicating underground cables are more resistant to failure. In the presence of overhead lines, the interaction between birds and vegetation as well as proximity to nearest desert areas and lakes are positive driving factors explaining much of the variation in unscheduled outages. Closeness to the nearest arterial road and the interaction between housing square footage and temperature are also significantly positive. A spatial error model was found to provide the best fit to the data. Resultant findings are useful for understanding and improving electrical infrastructure reliability. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords
Determinants (mathematics); Electric Power Distribution; Reliability In Engineering; Social Factors; Temperature Effect; Phoenix (ariz.); Arizona; Distribution; Electricity; Interruption; Outage; Reliability; System Reliability Assessment; Maintenance; Overhead; Model; Interruptions; Regression; Flashover; Failures; Performance; Hurricanes
Maliszewski, Paul; Larson, Elisabeth; Perrings, Charles. (2013). Valuing the Reliability of the Electrical Power Infrastructure: A Two-Stage Hedonic Approach. Urban Studies, 50(1), 72 – 87.
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Abstract
The reliability of electrical power supply is amongst the conditions that inform house purchase decisions in all urban areas. Reliability depends in part on the conditions of the power generation and distribution infrastructures involved, and in part on environmental conditions. Its value to homeowners may be capitalised into the value of the house. In this paper, a hedonic pricing approach is used to estimate the capitalised value of the reliability offered by distribution infrastructures and the environmental conditions with which they interact in Phoenix, Arizona. A first stage estimates the impact of infrastructure and environmental conditions on reliability. In a second stage, the capitalised value of reliability from the marginal willingness to pay for reliability revealed by house purchase decisions is estimated and used to infer the value of both infrastructural characteristics and environmental conditions.
Keywords
Willingness-to-pay; Residential Property-values; Economic Valuation; Choice Experiment; Urban Wetlands; Air-quality; Benefits; Identifiability; Specification; Determinants
Larson, Elisabeth K.; Grimm, Nancy B. (2012). Small-Scale and Extensive Hydrogeomorphic Modification and Water Redistribution in a Desert City and Implications for Regional Nitrogen Removal. Urban Ecosystems, 15(1), 71 – 85.
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Abstract
There are numerous examples of small-scale hydrogeomorphic manipulations within urban ecosystems. These modifications are motivated both by a need to handle storm drainage and by a human desire for aquatic ecosystems as places for recreation and aesthetics. In the Phoenix Arizona metropolitan area, two examples of these local modifications are artificial lakes and stormwater retention basins. Although lakes are not a natural feature of Sonoran Desert ecosystems, numerous artificial lakes are evident in the region. Retention basins are a common landscaping practice for preventing damage from rare but potentially large storm events. Here we attempt to quantify the heretofore unknown number and extent of these designed aquatic ecosystems and consider their potential impact on hydrologic landscape connectivity and regional nitrogen (N) removal. For lakes, we found that official GIS layers from local and state agencies had significant misclassifications and omissions. We used two published GIS datasets and state impoundment-permit information to determine the number, areal extent, and water source for artificial lakes. We discovered that there are 908-1,390 lakes in the Phoenix area, with the number varying according to level of aggregation. There are no existing GIS data on retention basins, so we employed drywell-permit data to estimate that there may be 10,000 retention basins in the region. Basic data on N stocks in these ecosystems are discussed within the context of the regional N budget. Accurate data on the extent and distribution of these designed ecosystems will be vital for water-resources planning and stormwater management.
Keywords
Urban; Urbanization; Retention; Phoenix