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where rising demands for an increasingly scarce and highly variable resource
threaten the “challenge of absolute water scarcity” (V
osmarty et al. 2000 , 287).
The U.S. Southwest is particularly vulnerable given historic mega-droughts that
have reduced regional water flows to as low as 25% (Monroe 2008 ). Predictions of a
warmer, drier climate will also likely reduce local watershed runoff in the future
(Ellis et al. 2008 ). Situated in the rapidly growing city of Phoenix, Arizona, our
study identifies 'hot spots' of high water consumption relative to various
determinants of demand in order to assist conservation planning through a targeted,
place-based approach.
In particular, we integrate typically disparate datasets and research approaches
using a Geographic Information System (GIS) while applying qualitative and
quantitative methods to examine perceived versus actual water demand for resi-
dential neighborhoods. Considering local perceptions as well as other household
and property characteristics (i.e., income, housing age, and vegetative land cover)
as critical determinants of demand, our integrated geospatial approach can help to
tailor water conservation initiatives to the particularities of places for enhanced
effectiveness. Although already significant, the portion of regional water demand
attributed to residential uses is expected to grow as houses replace farms and native
desert areas in metropolitan Phoenix, AZ (Wentz and Gober 2007 ). This develop-
ment involves a shift of land as well as water from farms to households, and as a
result, municipal water use will soon overtake agriculture as the leading sector of
region-wide demand (Larson et al. 2009b ; Keys et al. 2007 ). In the City of Phoenix
( 2005 ), 66% of total municipal demand is used for residential activities, primarily
for outdoor purposes such as irrigation and the maintenance of swimming pools in
single-family households.
According to Wentz and Gober (2007), three of the four factors determining
neighborhood water demand pertain to outdoor water use: lot size, pool ownership,
and groundcover type (i.e., irrigation-dependent grasses versus drought-tolerant
alternatives). The fourth significant determinant in their demand model was house-
hold size, which increases residential consumption due to a greater number of
people living in households. Building on this work, which also illustrated distinc-
tive spatial patterns in the determinants of water demand, our mixed-methods study
examines residential demand in relation to perceptions and other known drivers of
water use, and by extension, local conservation potential.
Our primary study unit is the neighborhood, the scale at which the determinants of
water demand (such as household and property attributes) often operate to influence
locally differentiated rates of consumption (Aitken et al. 1991 ). Few water demand
studies have been carried out at the neighborhood scale, which we define by census
block groups. The integrated methodology offers a geospatial approach to under-
standing the relationship between perceptual judgments about water use rates,
as gathered through a social survey, and actual demand, as observed through
household meters in the City of Phoenix, AZ. The application of our findings
expands beyond geospatial sciences and human-environment research to inform
targeted conservation programming and environmental planning. While identifying
or
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