facing climate changes: towards sustainable planning and management of water resources prof. ezio...
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Facing Climate Changes:Towards Sustainable
Planning and Management of Water Resources
Prof. Ezio Todini
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Main changes of Water Resources availability during the twentieth century
Measurements of temperature, precipitation, discharges, groundwater levels, water quality, etc., provide an important reference framework on the availability of water resources and on the extent of their reduction, mostly caused by:
the ongoing climatic changes the generalised over-exploitation of renewable sources the increased water pollution.
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A classical image of global temperature trends
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Global precipitation anomalies
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Main meteorological changes in Italy during the twentieth century
Over the entire country the following changes have been observed:
positive temperature trend, with induced increase in evapo- transpiration losses reduction of yearly precipitation totals spatio-temporal variation of distribution of rainfall events with:
reduced formation of snow cover and shrinking of glaciers appreciable reduction of low and mean river flows
increased rainfall intensity during storms with: increased probability of flood events
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(Brunetti et al, 2006)
Year
Ann
ual a
nd r
unni
ng m
ean
valu
es
Normalised Yearly Rainfall Totals over Italy
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a) Winter
b) Spring
c) Summer
d) Autumn
(Brunetti et al, 2001)
Space-time variation of rainfall over Italy
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Reno Measured Discharge at Casalecchio (1923-1995)
Winter
Spring
Year
Summer
Autumn
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(Alcamo et al., 2007)
Predicted precipitation changes in Europe
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(Kundzevicz et al., 2007)
Predicted flood frequency changes in Europe
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Until the end of the ‘80, water was considered one of the natural resources to be exploited, and traditionally
Planning and Managementof
Water Resources
were approached via
Deterministic or Stochastic Optimization
(Maas et al., 1962; James and Lee, 1971; Loucks et al., 1981)
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More recently,
Multi-criteria Techniques
have also been extensively used, in order to account for a wider variety of
Commensurable and Incommensurable Objectives
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At the end of the 80’ the introduction of the
Sustainability Concept (World Commission on Environment and Development, 1987)
which aims at fulfilling: • Environmental integrity• Economic efficiency• Equity for present and future generations
has radically changed the traditional perspectives.
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Sustainability Emerging Concepts
- Water must be considered as a limiting factor for economic growth and development
- Environmental aspects (especially water quality which may reduce water availability and quality of life) must be taken into consideration
- Socio-economic aspects must be taken into account- Legal and political (local, national and international)
issues (strategies, restrictions) must be considered- Uncertainty (including hydrological stochasticity,
climate change and future demand) has to be accounted for
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EMERGING REQIREMENTS
Sustainability requires studying problems in a
comprehensive way at catchment scale.
Furthermore, with the introduction of the sustainability concept classical optimisation in water resources, has lost its leading role with respect to the analysis of
environmental and socio-economical impactsof pre-defined development scenarios.
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Planning sustainable resources exploitation requires to take into account:
- the present situation- the socio-economic context - the availability of resources - the environmental carrying capacity
In addition it is also necesary:
- to place special attention on public requirements which implies strong interactions with population.
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Although the experience from developed countries indicates the need to establish a right balance between the market mechanisms and government interference as well as among technical/technological aspects, energy management and social aspects, all the water development and allocation plans seem still to follow a top-down approach, where the “participatory approach” is only meant as trying to promote the “blessing” of the general public on already taken decisions .
Unfortunately
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Sustainability
Can also be viewed as the capacity of reconciling high efficiency and effectiveness of interventions with the environmental compatibility and the actual needs and demands of the populations involved.
NOTE that these may be significantly affected by the foreseen population growth and climatic changes, as anticipated by the IPCC.
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Unfortunately, in absence of better political understanding of the drivers of sustainable development and of their complexity, economic growth remains the predominant driver for the policies of most countries and territories.
Short-term economic gains (especially in the conditions of low GDP) seem politically more attractive then the longer-term benefits associated with integration of sustainability requirements into policy making.
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There is the need for shared objectives and participated “description” of all the aspects and facets that may result from the planned resources allocation and management policies, which suffered in the past (and still frequently suffer today) of top down approaches.
The basic requirements
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In other words, more than the search for optimised policies, there is the need for a comprehensive description of the overall physical-environmental-social-economical system to make politicians, technicians and in particular stakeholders and end users, not only able to understand the advantages descending from the proposed strategies, but most of all, to be aware of the short and long term positive and negative consequences that may arise from their implementation.
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This description includes a fact finding and analysis phase, in which the real needs of the end users are established with a participatory approach, followed by a synthesis and communication phase, where the effort has to be placed into the definition of clear and understandable indicators.
The clearness of indicators and the ways in which they are communicated to the stakeholders is a fundamental step towards participated decisions, as requested by the WFD.
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It is in this context that alternative indicators to the GDP have been proposed in order to provide a more realistic measure of welfare, quality of life and quality of ecosystems and environment
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Alternative indicators to GDP
GNH – Gross National Happiness (Bhutan King Jigme Singye Wangchuck – 1972)
GPI – Genuine Progress Indicator
HPI – Happy Planet Index
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HPI vs GDP
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THE NEED FOR INTEGRTED DECISION SUPPORTING TOOLS
From all these aspects the need emerges for integrated planning and impact verification decision support tools, integrating over a geo-referenced database all the required models and tools to be used by planners to assess the consequences of interventions on a multiplicity of aspects, to navigate among the extremely large number of items and possibilities and to produce and implement development measures that will keep track of the environmental and socio-economic interactions, of public requirements and of administrative and legal viability.
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Existing Decision Support Systems (DSS)
tend to be too detailed in single model components and/or restricted to some of the aspects of the problem, without taking into comprehensively account for the
complex interrelations
among all the physical, socio-economical and environmental components
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Examples of Existing Decision Support Systems
• AQUATOOL – Polytechnical University Valencia • BASINS - US EPA• EGYPT DSS – ET&P• ENSIS – NIVA• IQQM - NSW Dept. Land and Water Cons.• IRAS – University of Cornell• MIKE BASINS - DHI • RIBASIM – Delft Hydraulics• SPATIAL DSS – NTUA• WATERWARE – Eureka 487• WEAP – Stockholm Institute
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PROSGeneral Water ResourcesManagement at catchmentscale
CONSNo economic and environmental aspects
No link with GIS
Does not allow dynamic inclusion of nodes
AQUATOOL – Polytechnical University Valencia
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PROSEnvironmentallyoriented
CONSPhysical aspectsdescription prevails over socio-economicalimpacts
BASINS - US EPA
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PROSMainly physical aspectsWater quantity and quality simulation.
CONSDoes not include scenario concept.Not linked to a GIS
IQQM - NSW Department of Land and Water Conservation
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PROSIntegrated GIS-DB
Physical simulation and optimisation
CONSNo socio-economicand environmentalimpact
MIKE BASINS - DHI
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PROSComprehensiveIncludesSocio-economical,Environmental andQuality of Life indicators
CONSToo complex as a generic tool
EGYPT DSS – ET&P
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PROSIncludes several modelsPerforms water allocation
CONSDoes not allow for Environmental and Socio-Economicalimpacts
Can import maps but does not provide GISfacilities
RIBASIM – Delft Hydraulics
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PROSIncorporates GIS and DBOpen architecture
CONSMore information system than DSS
Integration of componentsvery expensive
Scant documentation available
WATERWARE – Eureka 487
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PROSComprehensiveBased on DPSIR concepts
CONSDoes not include GIS/DB
Water Demand cannot be updated through feedbacks at each time step
WEAP – Stockholm Institute
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A new tool: the WaterStrategyMan DSS
• A comprehensive DSS• Uses WFD and DPSIR concepts and approaches• Fully imbedded in ARC-GIS• Uses the ARC-GIS Geo-Database• Includes interactive and user friendly graphical tools• Includes default data, such as: 1x1 km Geotopo30
1x1 km FAO Soil Map of the World 1x1 km Global Land Cover Characteristics Data Base 10x10 km Monthly average climatology• Allows for multi-criteria analysis of indicators
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Objectives of the WSM DSS
To support the strategy analysis at regional level
To compare strategies on the basis of different indicators
To help decision-makers to decide upon the best strategy, taking into account:
Regional development priorities
Social and economic constraints
Environmental constraints Local, national or
international legal constraints and directives
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The Four Main Functions of the DSS Describe the existing state of the water system Assess state in terms of:
Sources Usage Water cycles Environmental quality
Forecast state on the basis of: Assumed or envisaged scenarios Technical alternatives Management policies and actions
Evaluate impacts of actions
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Demand and Supply Schematization
SUPPLY NODES DEMAND NODESRenewable Groundwater SettlementFossil Groundwater Tourist site Coastal Zone Irrigation Site River Reach Industrial SiteReservoir (Storage – Small – Natural Lake) Animal Breeding Importing Exporting
Hydro-electricity production
TRANSHIPMENT NODES LINKSNetwork Reservoir Canal
Pipeline River Link Groundwater Link Return Flow Link
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River Basin Schematization
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The Analysis Procedure
Policy Options
Strategy Definition
Scenario + Strategy
WaterAllocation
ScenarioEvaluation
Strategy Evaluation
BaselineScenario
Current Patterns
of water availability
and use
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Generation of demand scenarioson population growth rates
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Seasonal Demand: Irrigation
Seasonal Demand: Tourism
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Generating hydrological scenarios
and seasonality
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Policy Options and ActionsPOLICY OPTIONS ACTIONS
A. Supply Enhancement A1. Unconventional/untapped resourcesA2. Surface Waters and precipitation (direct abstraction, dams, reservoirs)A3. Groundwater (drillings, wells)A4. DesalinationA5. ImportingA6. Water Reuse
B. Demand Management
B1. PricingB2. Irrigation method improvements (drip irrigation, enclosures)B3. Conservation measures in the home (water saving plumbing systems)B4. Recycling in industry and domestic useB5. Improved infrastructure to reduce losses (networks, storage facilities) B6. Raw material substitution and process changes in industry
C. Social–Developmental Policy
C1. Change in agricultural practices (low irrigation crops, genetic improvement) C2. Change of regional development policy (tourism/agriculture limitation)
D. Institutional Policies D1. Institutional Capacity Building(Education and awareness campaigns, Use of standards, Public participation, Stakeholder involvement, Conflict resolution, Contingency planning)
D2. Economic Policies(Water pricing, Cost recovery, Incentives)
D3. Environmental Policies(Enforcement of environmental standards and legislation, Monitoring, Penalties and fines, Impact and risk assessment)
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DesalinationWater ReuseReduction of network losses
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Building a strategy from actions and schedule
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Comparison made with BAU
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Scenario+Strategy Evaluation
Evaluation is based on indicators for: Sustainability of water resources Social/Economic benefits for water uses Environmental impacts on water
resources Compliance with legal, economic and
environmental constraints
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Performance at node level
Pollution Concentrations of fecal coliform counts in water bodies Concentrations of BOD / COD in water bodies Heavy metal concentrations in water bodies Decrease in effluent volume (%) Reduced pollution levels in water bodies after
wastewater treatment Demand
Increase in potable water (%) Reduction of actual water consumption (%)
Economics Increase of income (%)
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Item Indicator a. Sustainability of
resources
a1. Increased water availability with respect to baseline scenario (%) a2. Amount of groundwater reserves vs annual groundwater withdrawals a3. Annual regional water consumption (m3/cap) a4. Exploitation index
b. Demand b1. Consumption Index b2. Dependence on importing or on upstream catchment (%) b3. Coverage of water demand per sector
c. Water Quality c1. Increased amount of treated wastewater (%) c2. Area irrigated with treated effluent (%) c3. Improved drinking water quality (% of population)
d. Economy d1. Rate of cost recovery d2. Increased tourism revenues (%) d3. Increased revenues from agriculture d4. Increased revenues from industry d5. Total Cost, Direct Cost, Opportunity Cost, Environmental Cost
e. Environment e1. Average monthly BOD in freshwater resources e2. Average monthly nitrogen in freshwater resources e3. Average monthly phosphorus in freshwater resources
More Aggregated Indicators
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Reliability is the probability that any particular indicator value of its time series will be within the range of values considered;
Resilience is a criterion describing the speed of recovery from an unsatisfactory condition. It is the probability that a satisfactory value will follow an unsatisfactory value;
The Vulnerability statistical index measures the extent and/or duration of failures (e.g. unsatisfactory values) in a time series.
Performance Indexes
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The WSM DSS was conceived to formulate the Planning or Management problem by describing the complex interrelations among all the physical, socio-economical and environmental components
.....but what about Floods
Sustainable Flood Management
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The level of Complexity Increases
Flood risk alleviation and flood control mustbe approached with a “Holistic view” and must be integrated into a “Sustainable IWRM” type of analysis.
This poses several additional and presentlyunresolved problems.
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A first problem: the Time Scale
As opposed to droughts, that may lastseveral months or years, floods cannot be generally analysed on a monthly basis, since their physical duration (apart from few large rivers, such as the Nile) is shorter than a month.
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A second problem: the Risk
In order to account for, flood alleviation benefitsone cannot avoid introducing the concepts of uncertainty, extreme events and risk.
This is particularly true under the pressure ofclimate changes
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THE HOLISTIC APPROACH
The holistic approach to Flood Risk Managementwas advocated after the Mississippi flood, and implies looking at the problem in a broader sense,as illustrated in the sequel.
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HOLISTIC APPROACH TO RISK MANAGEMENT “PLANNING”
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HOLISTIC APPROACH TO RISK MANAGEMENT “EMERGENCY MANAGEMENT”
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THE SUSTAINABLE IWRM APPROACH
The sustainable approach broadens the holistic flood risk management not just to include a wide variety of non-structural interventions, such as restoration of wetlands, re-forestation, dry land-farming, but to radically change:
- How we think about floods- How we make choices as what to do- What options we seek to adopt- How we implement these options (Green, 2003)
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Which again leads to the need for new indicators
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DERIVING FLOOD INDICATORS AND INDEXES IS AN EXTREMELY COMPLEX PROBLEM
- Authorities generally perceive the flood problem in terms of structural, and mainly engineering interventions
- Flood time scales are incompatible with IWRM scenario based simulation models
- The flood risk analyses are extremely expensive operations based on detailed maps scantly available in several European countries.
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- The real time flood management scheme for the RiverTagliamento
- The flood alleviation scheme for the Rio Rivolo (Rivulet)
Two examples of unsustainable planning in Italy
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The River Tagliamento in Italy is a very good example toillustrate the complexity of deriving a sustainable IWRMapproach to flood risk alleviation.
The Tagliamento is supposed to be the last EuropeanRiver still bearing “natural conditions”
The case of the RiverTagliamento
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Photo Arno Mohl - WWF AustriaThe River Tagliamento in Italy
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Exceptionally preserved natural conditions
Wide variety of habitats (SIC)
Inestimable ecological value due to the presence of a riverine band
Extremely rare environment and panoramic views in Central EuropeFoto Arno Mohl - WWF Austria
A river with interconnected branches
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Photo A.Mohl - WWF Austria
Imagine the effects of an 8 m high dyke
The planned water detention area site
The planned intervention: a 40 M m3 Water Detention Area
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1) The problem was not analysed at the basin scale It was in fact formulated as a local hydraulic defence problem:
1.1) upstream Latisana 1.2) from Latisana to the sea
regardless to the interaction of the two portions of the river
Why the project is unsustainable?
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2) It was approached in traditional way without a real and detailed assessment of the environmental and social impact.
How the water detention areas would affect the destruction of habitats and the continuity of subsurface flows?
What would be the impact on the landscape and on the emerging eno-gastronomical activity?
Why the project is unsustainable?
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3) Consensus of local populations was not appropriately requested
This is mayby the most important issue that makes the proposed project unsustainable.
Why the project is unsustainable?
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Rio Rivolo (Rivulet)
Catchment Area 9 km2
Example of unsustainability the case of Rio Rivolo
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The dam site
The DAM
8 m tall and
179 m long
The dam site
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Terreaux e Bouzit (2005), convincingly proved that it is the implementation of structural measures aimed at reducing natural risks, often built with a limited space and time vision that, owing to a false sense of security, tend to increase the expected value of damages, which again imposes to create new structures in an endless spiral.
Final considerations
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CONCLUSIONS 1/2The concept of sustainability radically changed the IWR planning approaches from optimisation to scenario simulation analysis. But, decision makers have a different way of looking at problems and issues, which implies the need for developing specific meaningful indicators by integrating classical social, economical and environmental indicators.
Users response to demand management actions and quality of life indicators must be improved to assess the real impact and effectiveness of actions.
This requires the setting up of interesting social sciences and psychological modeling exercises.
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Nonetheless, under the pressure of climate changes we will inevitably need to:
1) totally modify our vision on welfare and quality of life;2) accept a reasonable level of risk;3) use as much as possible the newly available technologies (Telemetry, Radars, Satellites, Real Time Flood Forecasting Systems) to provide early warnings;4) radically change the flood risk mitigation approaches.
CONCLUSIONS 2/2
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Thank you for your patience and attention
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Detailed description of theWSM DSS
can be found at
http://www.geomin.unibo.it/hydro/WSM