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