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This is a presentation that I made on research to understand urban drought reslience
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Research to understand resilience of cities to drought:
three hypotheses Lawrence Alan Baker
Ecological Engineering Group Dept. Bioproducts and Biosystems Engineering
University of Minnesota USA
Presented at the European Society for Ecological Economics, June 14, 2011
Goals
• The problem of urban drought • Drought as a socio-ecological (SE)
phenomenon • Resilience to SE drought • Several research hypotheses
20
30
40
50
60
70
1970 1980 1990 2000 2010 2020 2030
% o
f po
pula
tion
Year
Urban
Rural
An urbanizing world: nearly 5 billion urban dwellers by 2030
Unorganized area in Ouagadougou, Burkina Faso
Global drought impacts, 1970-2007 Source: Kallis (2008)
Africa Asia South & central America
North. America
Europe
Disasters 222 226 87 12 36
Millions affected
310 1,493 61 0.03 14
Cost, million U.S. $
6 30 9 6500 20
Deaths 672,647 5,381 0 2 60
Projected Drought Pattern (Dai, 2011)
Drinking water
Bathing & laundry
Flush toilet
Washing machine
Water for production
2nd flush toilet
Turf irrigation
Liters per capita/day
3
250
50
1000 Swimming pool
100
Maslow’s Triangle for Water Use
Drought as a Socio-Ecological Phenomenon
Meterological drought – defined as deficit of rainfall over some period of time
Hydrological drought – defined on the basis of water supply (including groundwater and reservoir storage, relative to demand
Socio-ecological (SE) drought – defined based on the impact of depleted water availability on the social, economic, and ecological environment of human ecosystems.
Overarching hypothesis: The long-term impact of drought depends on the socio-ecological resilience of cities.
Period of Drought
Time
Impa
ct
Robust & resilient
Not robust, but resilient
Robust but not resilient
Neither robust nor resilient
Before Drought
After Drought
Resilience and Robustness in Response to Drought
Factors affecting drought resilience
• Antecedent environmental conditions
• Physical infrastructure
• Water governance
Antecedent environmental conditions 1. Urban groundwater depletion
Not just in arid lands
Chicago
Map of groundwater isopleths in Chicago, Illinois, North-central U.S.
Annual average T = 10 oC Annual average P = 86 cm
Groundwater depletion = 260 m
Antecedent environmental conditions: 2. Groundwater contamination
Causes: 1. Urbanization of agricultural land 2. Leaky sewers 3. Septic systems and latrines (esp.
Africa) 4. Animal waste 5. Landfills
Source: Wakida and Lerner (2005)
Nitrate concentrations in Phoenix, Arizona (USA)
Smoldering landfill in Ouagadougou, Burkina Faso
Physical infrastructure for resilience: the water infrastructure: Phoenix, Arizona (USA)
Imported water from Colorado River
Multiple reservoirs on two rivers
Large groundwater basin
Phoenix
Importation of Colorado River water via the Central Arizona-Phoenix Project
Total cost: $4 billion Capacity: 2.5 109 m3 per year
Agricultural buffer
Water governance
1. Levels of water governance 2. Water law (quantity) 3. Capacity to provide feedback 4. Capacity to respond
International river basins: 263 worldwide
Water governance example: Arizona’s “Active Management Areas”
• Includes the entire urban region (about 7 cities + agricultural belt) • Focus on groundwater management • Solid legal mandate
Informal governance
Water law: Who gets to use the water?
Characteristics:
• Rarely embedded in national constitutions (South Africa, Kenya) • Generally fragmented among levels of governance • Often based on common law, formed over time by judicial decisions • Rules of groundwater and surface water are usually different • Generally does not recognize economic value • International legal framework weak • Treaties are highly variable
Projected per capita water shortages in the Phoenix region driven by “first in right” appropriation (Source: Bolin et al., 2010. Local Environ. 15: 261–279)
Feedback for drought resilience
1. Ability to acquire hydrologic information – status of groundwater, stream monitoring, water deliveries, etc.
2. Transparency – data available
3. Accessibility of information for appropriate levels of governance
- “3-click rule”, no specialized software, appropriate technical level
ASU’s Decision Theater
Feedback: - transparent - accessible - timely
Capacity to respond:
1. Redundant water supplies (inter-basin transfers, surface + groundwater supplies, rainwater harvesting, etc.)
2. Intact water delivery system – low leakage losses
3. Agricultural buffer – system to acquire agricultural water during severe droughts
4. Water reuse infrastructure (irrigation)
5. Equitable water quantity law
6. Ability to enforce water conservation
Research Agenda General hypothesis: We can predict resilience of a city to drought of given severity based on antecedent physical conditions, the extent of environmental feedback, and the capacity to adapt.
Value: Practical- Ability to increase resilience (reduce vulnerability) to droughts. Theoretical – opportunity to develop transdisciplinary theory of human ecosystems
Highly interdisciplinary – engineering, hydrology, political science, sociology, geography
Site-based – one or more major cities on several continents
Duration: 5-10 years
Hydrologists
Economists
Environmental engineers
Planners
Lawyers
Sociologists
The City
Interdisciplinary approach