Kiersten von Trapp
UEP 232 Assignment 1
9/18/09
URL: http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B7XNM4R8PNX8-11&_cdi=29702&_user=201547&_orig=search&_coverDate=12/31/2007&_sk=999
929995&view=c&wchp=dGLbVlWzSkWA&md5=bfea7f675283cd5547ad59336f812dab&ie=/sdarticle.pdf
Project Name: Characterizing vulnerability to water scarcity: The case of a
groundwater-dependent, rapidly urbanizing region
Authors: Timothy W. Collins and Bob Bolin
Time Period: Copyright 2007
Data Used: Biophysical and Social vulnerability indices. Biophysical factors
included number of exempt wells without access to basin-fill aquifer, and well
spacing. Social factors included population, housing units, access to resources
(based on race and age), socioeconomic status, and place dependency
(seasonal/recreational housing units). Water provider type data was also
included. These factors included proportion of housing units within municipal
water provider area, within private water provider area and with exempt wells.
These factors were all assessed at the census block group level.
Data Sources: US Bureau of the Census (2000), Arizona Department of
Economic Security (2006), Yavapai County (2004), Arizona Department of Water
Resources.
Geographic Extent of Study: The Prescott Active Management Area in
Arizona’s Central Highlands
The goal of the research was to assess the overall vulnerability of this Active
Management Area to water scarcity. Overall vulnerability was based on social
and biophysical vulnerability. This area was of particular interest as groundwater
is its sole water source. In addition, this region, which is about 150 miles north
of the Phoenix metro area, is experiencing rapid growth. Dense development
that depends largely on exempt wells has led to over-pumping and, as a result, a
drop in the water table.
Mapping and spatial analysis was key to this project. The article first displayed
maps that represented biophysical vulnerability and maps that represented
sociodemographic vulnerability. Finally, these two components of water scarcity
were put into one map to show an aggregate assessment of the vulnerability of
this area. GIS was used to show areas of vulnerability based on hydrologic
variability in water resource availability within a groundwater basin, three types
of water management systems, and ten sociodemographic characteristics. The
maps used in the study are shown below.
The results of the study indicated that areas where biophysical vulnerability was
high did not necessarily correlate with areas that where sociodemocraphic
vulnerability was high. Local differences in vulnerability were interrelated,
influenced by laws that increase social vulnerability and economic reliance on
urbanization. Throughout the entire area, the project concluded that, “a high
degree of spatial variability in overall vulnerability to water scarcity exists in
relative rather than absolute terms.”
This study looked at an area that is being analyzed in many ways. The spatial
aspect of this project was significant because it added a further dimension to the
study of vulnerability that had not been looked at previously. The results of the
spatial analysis showed trends that might not have been able to be seen without
GIS.
Further areas that could be explored in a project like this are social behaviors
and their affects on water supply. This study only took documented
sociodemographic variables into consideration when measuring vulnerability.
However, a more in depth understanding of local water uses and preferences
would be useful to assess vulnerability more accurately. This could be analyzed
through statistics and does not necessarily have to be a spatial question.
However, a geo-spatial analysis of preferences and practices could show
additional influences on vulnerability that are connected to location.