This project provided insights about drought in the Southwest: its causes, its impacts, and the potential vulnerability of Arizona’s expanding communities. CLIMAS researchers worked in coordination with the Governor’s Drought Task Force (GDTF) to provide basic research and information on drought to help the GDTF with effective drought planning for Arizona. The project:
Drought lurks constantly at the edges of our lives in the desert Southwest. In a region that supports growing human populations, agriculture, ranching, industry, recreation, and diverse wilderness communities, a sufficient and predictable water supply is crucial. Yet, since Southwestern regions can receive as little as 5 to 15 inches of rain in a normal year, a severe drought often means that humans and ecosystems already coping with a vulnerable water supply do not have sufficient reserves to deal with less precipitation.
All regions of the world are vulnerable to drought. The degree to which the physical environment, animal populations, and human communities can absorb the impacts of drought, however, differs greatly. Different areas of the country can also expect varying frequency of drought. While the Southwestern United States experienced drought 43 percent of the time in a recent 50 year period (1944-1984, defining drought as less than 75 percent of average precipitation), the wetter Northwest only suffered from drought conditions 13 percent of the time (Holechek, et al. 1998). Arizona experienced three severe sustained droughts in the 20th century, one in the 1900s, one in the 1950s, and an ongoing drought that began in the late 1990s. All of these periods of drought were more than mere precipitation deficits; they impacted the ecology, economy, agriculture, and society. Preparing for future drought is vital, since drought is a normal part of the climate of Southwest.
According to the level of drought planning and the economic, social, and political resources available to those impacted, drought can either be seen as a part of the region’s climate or a recurring disaster. Proactive measures—including learning about drought, drafting regional drought plans, and encouraging long-term perspectives on drought mitigation—can stop what climatologists have coined the “Hydro-Illogical Cycle,” a reactionary loop of human response to drought.
Several terms are vital to understanding drought and drought discussion in the Southwest.
Drought is defined most succinctly as “insufficient water to meet needs” (Redmond 2002), which takes into account a precipitation deficit relative to “normal” levels, and the influence a growing population can have on water demand. For example, a city in New York State could experience a water shortage even without experiencing record-low rain and snowfall, simply because the growing population demands more water than the aquifers can supply. In the Southwest, we experience both extended precipitation deficits and the added stress of growing urban populations. Annually, we draw more water from our aquifers than rain and snowmelt can provide to refill them.
Vulnerability is a term closely tied to the definition of drought above, since it describes the likelihood of an individual or group to experience negative physical or economic impacts due to drought. Vulnerability also depends on the political, social, and economic system in place. Imagine two farmers living in adjacent farms. While they experience the same precipitation deficit, Farmer 1 is able to plan for a drought by investing in non-agricultural sectors, and has insurance. Farmer 2 has bad credit, and recently purchased the farm. Farmer 1 may be able to adapt to the drought, at least in the short term, while we consider Farmer 2 to be highly vulnerable to even short term, mild drought.
Mitigation in this context means attempting to relieve the negative impacts of drought. It also implies planning efforts, and describes efforts to stem or lessen the negative effects of drought by reducing vulnerabilities, rather than belatedly reacting to a drought.
Many people have recognized the need for a comprehensive drought-planning network in the United States. Until recently, however, the drafting and implementation of drought legislation, allocation of funds, and mitigation programs were completed only at regional or state scales and under the discretion of small committees. Many states began calling for a comprehensive system of drought planning, fund allocation, and communication. In 2003, legislators wrote the National Drought Preparedness Act of 2003, draft legislation for a comprehensive national drought policy to be headed by a National Drought Council within the U.S. Department of Agriculture (USDA). Congress has not yet voted on this legislation. Part of the Act establishes a drought assistance fund, administered by the USDA, which would help states mitigate drought impacts and develop drought preparedness programs around the nation. (See more at the Western Governors’ Association.)
The Governor’s Drought Task Force completed the Arizona Drought Preparedness Plan in October 2004. CLIMAS researchers wrote parts of the drought plan and background document, and contributed research and data to Drought Task Force advisory groups.
At its inception, CLIMAS reported on climate and weather conditions and forecasts through its website and CLIMAS Update newsletter. Beginning with the 2002–2003 End InSight project, CLIMAS closely monitored drought and reported monthly on drought and hydroclimatic conditions through the Southwest Climate Outlook (now in collaboration with Arizona Cooperative Extension). The following section describes other CLIMAS activities related to drought monitoring.
Monitoring drought status is the backbone of the 2004 Arizona Drought Preparedness Plan. CLIMAS scientists have been members of the multi-agency Arizona Drought Monitoring Technical Committee (MTC) since its inception, and CLIMAS continues to contribute to improvements in drought monitoring. The MTC reports drought status each month to the director of the Arizona Department of Water Resources (ADWR - the lead agency for drought) and in cases of severe drought, to an Interagency Coordinating Committee consisting of representatives from state and federal agencies.
CLIMAS collaborated with Arizona Cooperative Extension and ADWR to develop an innovative program of county-level volunteer drought monitoring through implementation of Local Area Impact Assessment Groups (LAIAGs), as recommended in the Arizona Drought Preparedness Plan. The pilot group was formed in fall 2005 in Cochise County in southeastern Arizona and was made up of participants from across the county.
One function of the LAIAGs was to monitor and report drought impacts to the MTC. LAIAGs provide primarily qualitative reports of drought impacts. These reports were designed to aid the MTC in bridging a key gap in drought status assessments by helping to define the connection between quantitative monitoring data, such as precipitation and streamflow, and the impacts associated with various stages of drought severity. Some LAIAG volunteers also contributed unofficial precipitation observations to Arizona Rain Log, a collaboration between Arizona Cooperative Extension and the SAHRA NSF Science and Technology Center at the University of Arizona. Making the data-impacts connection helped decision makers and emergency managers in anticipating drought impacts and defining appropriate mitigation and response measures. It also helped communities understand local drought conditions and impacts, and better prepare for future drought.
With funding from The University of Arizona Water Sustainability Program, CLIMAS began development of a database of existing drought impacts from state agricultural data, news reports, wildlife statistics, and other sources. In conjunction with ADWR and the National Drought Mitigation Center, CLIMAS consolidated the database and developed protocols for data collection and input.
A key aspect of developing climate services for the Southwest is building the capacity for citizens to understand climate information and use it in operations and decisions to mitigate drought-related risk. Over the last several years, CLIMAS and partners such as SAHRA, Arizona Cooperative Extension, the Arizona Water Institute, and others convened workshops on drought, climate variability, and climate change. The goals of the workshops were to improve understanding about climate and how it affects the Southwest, learn how to use various online tools to evaluate climate information, provide fundamental information about developing local-level drought plans, and learn about stakeholder needs for information on drought and climate change.
CLIMAS researchers analyzed drought patterns over time and space to better understand past events, to provide reports of current conditions, and to forecast future climate patterns for stakeholders. Analysis of historical drought included looking at instrumental atmospheric and hydrologic data from the past century in the Southwest. In addition, CLIMAS paleoclimate research provided insight into prehistoric drought occurrence by reconstructing winter precipitation for the Southwest. More frequent droughts affected different topographic areas or smaller portions of the state, so it is important to understand drought events at many scales. More frequent droughts affect different topographic areas or smaller portions of the state, so it is important to understand drought events at many scales.
Historical and current drought information synthesized by CLIMAS researchers provides part of the background necessary for drought planning. CLIMAS also provides “one stop shopping” for up-to-date climate information, including drought information, through the monthly Southwest Climate Outlook.
In order to provide a preliminary picture of drought variations across Arizona, CLIMAS researchers compiled and analyzed historical NOAA climate division data for the period, 1895 to 2002. Water year (October–September) precipitation data and drought indices such as the Palmer Drought Severity Index and the Standardized Precipitation Index were analyzed in order to describe drought severity and variability and their spatial patterns across the state. These data were then compared with indices that measure large-scale atmospheric circulation patterns associated with multi-year variations in Pacific Ocean circulation, such as the Southern Oscillation Index and Pacific Decadal Oscillation. These measures reflect assorted qualities of drought on varied, but overlapping, time-scales. Each portrays drought severity, duration, and extent in a slightly different way.
In addition, each month, the Southwest Climate Outlook looks at drought at the local, regional, state, and national scale in order to provide a comprehensive depiction of current and forecasted conditions. It combines climate, water resources, and fire maps and data from national and state level institutions, with news highlights, interpretation and expert assessment of these products as they pertain to Arizona and New Mexico. Graphics illustrate climate trends for the region, as well as for discrete sites, and offer another tool to resource managers and decisionmakers.
A report and drought fact sheets have been produced to aid decision makers as they prepare for drought. An initial drought assessment,“Drought and Climate in Arizona: Top Ten Questions & Answers" provides lawmakers and the public with questions and answers about major climate-related aspects of drought including history, long-term averages, seasonality, interannual and long-term spatial and temporal variability, climate extremes, and climatic forcing. For example, this study revealed that the El Niño-Southern Oscillation connection with drought is stronger in southern Arizona than elsewhere in the state. Another key finding is that year-to-year precipitation variability in Arizona was highest between around 1930-1965, and that this variability has been increasing, again, in recent years.
This aspect of the CLIMAS drought research effort examined how non-climatic factors affect societal vulnerability to drought and which mitigation approaches can help reduce drought vulnerability in Arizona. Four projects, described below, assessed drought hazard planning in municipalities, community vulnerability to drought, potential drought mitigation strategies, and impediments to implementing the Arizona Drought Preparedness Plan.
The first project assessed societal vulnerability to drought using a hazard assessment approach. Societal response to drought has typically been reactionary, incomplete, and costly. Increasingly, however, communities, states, and even nations are drafting proactive mitigation plans to better deal with recurring natural hazards. This project took a closer look at flood and other risk-reduction actions and evaluated the extent to which these were applicable to drought risk mitigation at a municipal level.
A second project addressed the concept of vulnerability to drought. Unlike past drought research, vulnerability research examined how drought impacts result from interactions of social, political, and economic systems. This research identified societal buffering mechanisms that mitigate the effects of drought.
A third project involved a comparative evaluation of drought mitigation strategies. Research results summarize the feasibility, effectiveness, and longevity of recommended mitigation strategies. CLIMAS researchers reviewed other states’ drought plans, which provided a synopsis of mitigation opportunities and a theoretical framework of the social dimensions of drought.
The fourth project isolated the potential difficulties in implementing the Arizona Drought Preparedness Plan (ADPP). The ADPP aimed to mitigate the effects of drought through rigorous drought monitoring and enhanced communication between state agencies and Arizona communities. The ADPP calls for local groups to participate in drought impact monitoring, improve local drought planning capacity, and enhance communication between localities and the state's drought monitoring committee. Successful drought mitigation hinges on local and state-level collaboration, which can be hampered by hidden barriers. This project sought to uncover the potential impediments to implementing the drought plan by focusing on the difficulties in drought plan implementation as it related to geographic boundaries, social tensions, and on specific drought plan mitigation recommendations for rural communities.
A comprehensive review of current Arizona county and municipal planning documents was carried out to examine how various natural hazards have been incorporated into these plans. The hazard plans were analyzed for presence or absence of particular mitigation or response elements and ranked for the number of critical elements found in each plan that pertained to water shortage and drought. In addition, the content of these mitigation and response protocols was analyzed for various qualities that ensure risk reduction or provide measures recommended in various disaster relief acts.
To evaluate effective strategies for mitigating drought and reducing vulnerability, researchers conducted phone interviews with drought planners and resource managers in other states, and thoroughly reviewed states’ drought plans and archives. Integrating these qualitative methods with quantitative data and methods—such as spatial analysis using GIS (Geographic Information System) technology—will help researchers develop a more complete model of drought vulnerability and of how to evaluate and reduce it through effective mitigation options.
Researchers isolated the impediments to implementing the Arizona Drought Preparedness through interviews with sixteen key decision makers, including water providers, land managers, NGO staff, irrigation district leaders, and municipal officials.
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Holechek, J., R. Pieper, and C. Herbal, 1998. Range management: Principles and practices. Third edition. Prentice Hall: Upper Saddle River, New Jersey.
Jacobs, K., and G. Garfin. 2004. Arizona’s drought planning: focusing on adaptation. Water Resources Impact, 6(4):14-17.
Jacobs, K., G. Garfin, and B. Morehouse. 2005. Climate science and drought planning: the Arizona Experience. Journal of the American Water Resources Association, 41: 437-445.
National Drought Mitigation Center.The Hydro-Illogical Cycle. From “Planning for Drought” online, University of Lincoln-Nebraska: http://www.drought.unl.edu/plan/cycle.htm. Accessed April 19, 2004.
Redmond, K.T. 2002. The depiction of drought: a commentary. Bulletin of the American Meteorological Society, 83(8):1143–1147.
Sonnett, J., B. J. Morehouse, T. D. Finger, G. Garfin, and N. Rattray. 2005. Drought and declining reservoirs: Comparing media discourse in Arizona and New Mexico, 2002–2004. Global Environmental Change, 16:95-113.
Downey, S. 2004. Drought Mitigation and Adaptation: Discussions with State Drought Planners. A report to the Arizona Drought Task Force, 2004.
Gilbert, A. 2005. A Study of Potential Difficulties in Implementing the Governor’s Drought Preparedness Plan in the Little Colorado River Basin, Arizona. A report to the Arizona Drought Task Force, 2005.
Simpson, S. L. 2004. Impacts of drought on Arizona’s wildlife and in increasing urban human-wildlife conflicts: The confounded influence of ecology, animal behavior,and human societal values. A report to the Arizona Drought Task Force, 2004.