dss for integrated water resources management (iwrm) simulation based mc optimization ddr. kurt...

DSS for Integrated DSS for Integrated Water Resources Water Resources

Management (IWRM)Management (IWRM)

DSS for Integrated DSS for Integrated Water Resources Water Resources

Management (IWRM)Management (IWRM)

Simulation based MC optimization

DDr. Kurt Fedra ESS GmbH, [email protected] http://www.ess.co.atEnvironmental Software & Services A-2352 Gumpoldskirchen

DDr. Kurt Fedra ESS GmbH, [email protected] http://www.ess.co.atEnvironmental Software & Services A-2352 Gumpoldskirchen

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River basin scale perspectiveRiver basin scale perspective EU Directive 2000/60/ECEU Directive 2000/60/EC

Basic principle:Basic principle:Conservation lawsConservation laws (mass, energy) are used (mass, energy) are used

to describe dynamic water budgets.to describe dynamic water budgets.Basic unit: Basic unit: hydrographic catchmenthydrographic catchment or river or river

basin, naturally bounded, well defined.basin, naturally bounded, well defined.Complications: Complications: • inter-basin transfersinter-basin transfers• aquifer across catchment boundariesaquifer across catchment boundaries• mismatch with administrative unitsmismatch with administrative units

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Water resource MC optimizationWater resource MC optimizationWater resource MC optimizationWater resource MC optimizationDesign or select policies to

• Maximize the benefits• Minimize the costs

Using multiple criteria in parallel:1.physical/hydrological 2.monetary (socio-economic) 3.environmental

Economic (participatory) approach:Assumes that (rational) individuals maximize

welfare (individual and collective utility) as they conceive it, forward looking and consistently.

G.Becker, 1993

Design or select policies to

• Maximize the benefits• Minimize the costs

Using multiple criteria in parallel:1.physical/hydrological 2.monetary (socio-economic) 3.environmental

Economic (participatory) approach:Assumes that (rational) individuals maximize

welfare (individual and collective utility) as they conceive it, forward looking and consistently.

G.Becker, 1993

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In summary:In summary:Simulation-based optimization can identify

possibilities for considerable

INCREASES OF NET BENEFITS (improvements in several criteria)

• Globally (entire basin)• Sectorally (e.g., irrigated agriculture)• Geographically (administrative units or

hydrographically by sub-basin)

Mechanisms to distribute benefits equitably lead to win-win solutions

Simulation-based optimization can identify possibilities for considerable





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Multi criteria optimization:Multi criteria optimization:

1. Model the behavior of the system (river basin) in sufficient detail (distributed, dynamic, non-linear) to generate meaningful criteria:

dynamic topological (network) water resources model with daily time-step, coupled water quality model

1. Model the behavior of the system (river basin) in sufficient detail (distributed, dynamic, non-linear) to generate meaningful criteria:

dynamic topological (network) water resources model with daily time-step, coupled water quality model

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Multi criteria optimization:Multi criteria optimization:

1. sufficient detail: all major actors or stakeholder find themselves represented

2. meaningful criteria: all criteria

are relevant for the decision, measurable (quantified, scalar or at least ordinal)

1. sufficient detail: all major actors or stakeholder find themselves represented

2. meaningful criteria: all criteria

are relevant for the decision, measurable (quantified, scalar or at least ordinal)

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A topological model: nodes and reachesA topological model: nodes and reaches

A river basin is represented as a set of nodes and reaches connecting them.

NODES produce, consume, store, and change water quality;

REACHES transport it between nodes

AQUIFERS underlying the network

• Costs to supply water, damages, shortfall

• Benefits from satisfied demand, compliance

A river basin is represented as a set of nodes and reaches connecting them.

NODES produce, consume, store, and change water quality;

REACHES transport it between nodes

AQUIFERS underlying the network

• Costs to supply water, damages, shortfall

• Benefits from satisfied demand, compliance

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Gediz River basin, Turkey:Gediz River basin, Turkey:

Semi-arid, 18,000 km2 1,600,000 people

Rapid demographic and economic growth, supports the city of Izmir, drains into the Bay of Izmir, shallow, enclosed, vulnerable

• Recurrent droughts• High level of pollution• Dominant agricultural water use• Water fully allocated• Overexploitation of groundwater

Semi-arid, 18,000 km2 1,600,000 people

Rapid demographic and economic growth, supports the city of Izmir, drains into the Bay of Izmir, shallow, enclosed, vulnerable

• Recurrent droughts• High level of pollution• Dominant agricultural water use• Water fully allocated• Overexploitation of groundwater

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Gediz River Basin:Gediz River Basin:

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Model structure:Model structure:

NODES have type specific attributes and complex, dynamic behavior

Different simulation models describe: • Behavior of individual nodes• Behavior of the network

Makes it possible to cascade models:

rainfall-runoff water resources water quality

irrigation

NODES have type specific attributes and complex, dynamic behavior

Different simulation models describe: • Behavior of individual nodes• Behavior of the network

Makes it possible to cascade models:

rainfall-runoff water resources water quality

irrigation

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START water input, required start point generic, well, sping,

subcatchment, transfer, desalination

END export from the network, required endpoint for a model

CONFLUENCE combines two inflows, passive GEOMETRY auxiliar node, no hydraulic

function CONTROL monitors and records flow,

compares with targetspassiv, MINtarget, MAXtarget,

combined, calibration

START water input, required start point generic, well, sping,

subcatchment, transfer, desalination

END export from the network, required endpoint for a model

CONFLUENCE combines two inflows, passive GEOMETRY auxiliar node, no hydraulic

function CONTROL monitors and records flow,

compares with targetspassiv, MINtarget, MAXtarget,

combined, calibration

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DEMAND water demand and use, losses and consumptive use

generic, municipal, touristic, industrial, light industry,

commercial, services, irrigation, agriculture

RESERVOIR reservoirs with dams, and natural lakes

DIVERSIONdiversion or bifurcation node, splits a reach into two branches OR extracts water from the main stream

RECHARGE adds water to an aquifer TREATMENT affects only water quality

DEMAND water demand and use, losses and consumptive use

generic, municipal, touristic, industrial, light industry,

commercial, services, irrigation, agriculture

RESERVOIR reservoirs with dams, and natural lakes

DIVERSIONdiversion or bifurcation node, splits a reach into two branches OR extracts water from the main stream

RECHARGE adds water to an aquifer TREATMENT affects only water quality

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AQUIFERS one or more linked groundwater bodies underlying NODES and REACHES, connected through:

• Sources (springs, wells)

• Sinks (losses, seepage)

• Interaction with REACHES

• Recharge: – Natural (rainfall, temperature, land cover)– Artificial (recharge wells)

AQUIFERS one or more linked groundwater bodies underlying NODES and REACHES, connected through:

• Sources (springs, wells)

• Sinks (losses, seepage)

• Interaction with REACHES

• Recharge: – Natural (rainfall, temperature, land cover)– Artificial (recharge wells)

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Benefits and CostsBenefits and Costs

Nodes are described by Nodes are described by cost cost functions:functions:

– InvestmentInvestment

– Operating cost (OMR)Operating cost (OMR)

– Life time of project/structureLife time of project/structure

– Discount ratesDiscount rates

BenefitsBenefits per unit water supplied and used. per unit water supplied and used.

Computation of NPV (net present value) for Computation of NPV (net present value) for comparison of scenarioscomparison of scenarios

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Benefits and CostsBenefits and Costs

Direct monetary:Direct monetary:• Investment, operations, damage, Investment, operations, damage,

producer benefits producer benefits (irrigation)(irrigation)

Non-monetaryNon-monetary: based on (contingent) : based on (contingent) valuation valuation (hypothetical markets):(hypothetical markets):

• Shortfall costs, penalties, benefits of Shortfall costs, penalties, benefits of compliance compliance (in stream use, environmental use)(in stream use, environmental use)

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Process representation:Process representation:Sources of water, inputs: START NODES

– Tributaries (simulated by the rainfall-runoff model),

– Wells and well fields, – Inter basin transfer,– Desalination,– Water harvesting,– Direct rainfall (reservoirs, reaches)– Lateral inflow to reaches– Groundwater recharge

Sources of water, inputs: START NODES– Tributaries (simulated by the rainfall-runoff model),

– Wells and well fields, – Inter basin transfer,– Desalination,– Water harvesting,– Direct rainfall (reservoirs, reaches)– Lateral inflow to reaches– Groundwater recharge

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Process representation:Process representation:Water use, DEMAND NODES

Irrigation districts, settlements, industries, wetlands

• Conveiance losses

• Consumptive use

• Evaporation and seepage

• Bypass or spill

• Return flow losses

Water use, DEMAND NODES

Irrigation districts, settlements, industries, wetlands

• Conveiance losses

• Consumptive use


• Bypass or spill

• Return flow losses

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Process representation:Process representation:Water storage, RESERVOIR NODES


• Direct precipitation

• Local catchment

• Dynamic storage

• Release

• Spillage

Water storage, RESERVOIR NODES



• Local catchment

• Dynamic storage

• Release

• Spillage

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Process representation:Process representation:Water allocation, DIVERSION NODES

• Constant ratio (fixed weir) or controlled diversion (target) flow, possibly demand driven (real-time control)

• Allocation priorities (downstream requirements)

Water allocation, DIVERSION NODES

• Constant ratio (fixed weir) or controlled diversion (target) flow, possibly demand driven (real-time control)

• Allocation priorities (downstream requirements)

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Process representation:Process representation:Flow constraints, CONTROL NODES

Constant or dynamic constraints:

• Minimum flow requirements

• Maximum flow: flooding (non-linear damage)

Flow constraints, CONTROL NODES

Constant or dynamic constraints:

• Minimum flow requirements

• Maximum flow: flooding (non-linear damage)

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Process representation:Process representation:Groundwater, AQUIFERS

• Natural recharge, evaporative (through soil moisture) losses, deep percolation

• Artificial recharge (recharge nodes)

• Recharge from all seepage losses

• Provide input to start nodes:wells (pumped) or natural springs

Groundwater, AQUIFERS

• Natural recharge, evaporative (through soil moisture) losses, deep percolation

• Artificial recharge (recharge nodes)

• Recharge from all seepage losses

• Provide input to start nodes:wells (pumped) or natural springs

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Process representation:Process representation:Water flow, REACHES

• Simple routing (Muskingum, variable time step)

• Lateral inflow


• Evaporation

• Seepage (groundwater exchange)

Water flow, REACHES

• Simple routing (Muskingum, variable time step)

• Lateral inflow


• Evaporation

• Seepage (groundwater exchange)

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Optimization: STEP 1Optimization: STEP 1CONSTRAINTS:

Specify an acceptable system performance in terms of lower and upper bounds of criteria:

• Minimum amount of water available

• Maximum costs acceptable

• Minimum Benefits expected

CONSTRAINTS:

Specify an acceptable system performance in terms of lower and upper bounds of criteria:

• Minimum amount of water available

• Maximum costs acceptable

• Minimum Benefits expected

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Water resources systems optimization:Water resources systems optimization:

Definition of optimality:

• Acceptability, satisficing

• Requires a participatory approach:– Identification and involvement of major

actors, stakeholders– Shared information basis– Easy access, intuitive understanding– Web based, local workshops

Definition of optimality:

• Acceptability, satisficing

• Requires a participatory approach:– Identification and involvement of major

actors, stakeholders– Shared information basis– Easy access, intuitive understanding– Web based, local workshops

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Water resources systems optimization:Water resources systems optimization:

Acceptability, satisficing:

Easier for stakeholders to define several fixed targets as constraints than multiple objectives and trade offs, weights, preferences, etc.

Acceptability, satisficing:

Easier for stakeholders to define several fixed targets as constraints than multiple objectives and trade offs, weights, preferences, etc.

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System performance criteria:System performance criteria:• Supply/Demand, availability

• Reliability of Supply (%)

• Efficiencies (water, economic)

• Sustainability (content change)

• Water quality

• Costs and benefits

• Supply/Demand, availability

• Reliability of Supply (%)

• Efficiencies (water, economic)

• Sustainability (content change)

• Water quality

• Costs and benefits

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System performance criteria:System performance criteria:

• Diversion performance (%): the percentage of all "events" (summed over all diversion nodes and days) where the diversion target can be met;

• Allocation efficiency (%): the percentage of supply diverted to supply nodes that matches demands; all supply beyond demand is "wasted" and decreases allocation efficiency,

• Diversion performance (%): the percentage of all "events" (summed over all diversion nodes and days) where the diversion target can be met;

• Allocation efficiency (%): the percentage of supply diverted to supply nodes that matches demands; all supply beyond demand is "wasted" and decreases allocation efficiency,

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System performance criteria:System performance criteria:• Unallocated (%): the total amount of water that

is unallocated at reservoirs (spilled), diversions (beyond diversion and downstream targets), control nodes (exceeding a minimum flow constraint), expressed as a percentage of the total amount of water the passes through these nodes.

• Water Shortfall: the total amount of water "missing" from the total demand, summed overall all reservoir, demand, diversion, recharge and control nodes, over all days, expressed as a percentage of all stated "demands" including releases, diversions, and in-stream flow constraints.

• Unallocated (%): the total amount of water that is unallocated at reservoirs (spilled), diversions (beyond diversion and downstream targets), control nodes (exceeding a minimum flow constraint), expressed as a percentage of the total amount of water the passes through these nodes.

• Water Shortfall: the total amount of water "missing" from the total demand, summed overall all reservoir, demand, diversion, recharge and control nodes, over all days, expressed as a percentage of all stated "demands" including releases, diversions, and in-stream flow constraints.

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System performance criteria:System performance criteria:• Content Change: change of water value,

expressed as a percentage from the initial state at the beginning of the current (water) simulation year: measure of sustainability

• Flooding days: days of flooding; a flood occurs if at any control node the flow exceeds a maximum flow constraint.

• Flooding extent: the percentage of all "floods" (summed over all control nodes with a maximum flow constraint and days) as a percentage of all "events";

• Content Change: change of water value, expressed as a percentage from the initial state at the beginning of the current (water) simulation year: measure of sustainability

• Flooding days: days of flooding; a flood occurs if at any control node the flow exceeds a maximum flow constraint.

• Flooding extent: the percentage of all "floods" (summed over all control nodes with a maximum flow constraint and days) as a percentage of all "events";

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System performance criteria:System performance criteria:• Economic efficiency: the total benefit

per water available/supplied in €/m3

• Economic efficiency, direct: the direct, monetary benefit per unit water available/supplied

• Economic efficiency: the total benefit per water available/supplied in €/m3

• Economic efficiency, direct: the direct, monetary benefit per unit water available/supplied

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System performance criteria:System performance criteria:• Benefit/Cost: ratio of all benefits divided

by all costs accounted, including non-tangible elements and penalties.

• Benefit/Cost, direct: ratio of all direct monetary benefits over all direct monetary costs.

• Net benefit: Total benefit minus total cost, per capita.

• Total Benefit: Sum of all benefits, per capita.

• Benefit/Cost: ratio of all benefits divided by all costs accounted, including non-tangible elements and penalties.

• Benefit/Cost, direct: ratio of all direct monetary benefits over all direct monetary costs.

• Net benefit: Total benefit minus total cost, per capita.

• Total Benefit: Sum of all benefits, per capita.

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System performance criteria:System performance criteria:• Total Cost: Sum of all costs, per

capita. • Direct net benefits: Sum of all direct

monetary benefits minus sum of all direct monetary costs, per capita.

• Direct benefit: Sum of all direct monetary benefits, per capita.

• Total Cost, direct.: Sum of all direct monetary costs, per capita.

• Total Cost: Sum of all costs, per capita.

• Direct net benefits: Sum of all direct monetary benefits minus sum of all direct monetary costs, per capita.

• Direct benefit: Sum of all direct monetary benefits, per capita.

• Total Cost, direct.: Sum of all direct monetary costs, per capita.

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System performance criteria:System performance criteria:• Water Cost: Total cost of water, per m3:

Sum of all costs divided by the total amount of water supplied against demands at demand nodes, (diversions, control nodes)

• Water Cost, direct: Total direct monetary costs of water: as above, but considering only direct monetary costs.

• Water Cost: Total cost of water, per m3: Sum of all costs divided by the total amount of water supplied against demands at demand nodes, (diversions, control nodes)

• Water Cost, direct: Total direct monetary costs of water: as above, but considering only direct monetary costs.

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Optimization STEP 1:Optimization STEP 1:CONSTRAINTS:

GLOBAL: apply to some general, aggregate measure for the entire basin

SECTORAL: apply to a sector like agriculture industry, domestic, environment only

LOCAL (node specific):At LOCATION node FROM day – TO day

CONCEPT (flow, cost, benefit, ratio)

Must be between MIN – MAX

CONSTRAINTS:

GLOBAL: apply to some general, aggregate measure for the entire basin

SECTORAL: apply to a sector like agriculture industry, domestic, environment only

LOCAL (node specific):At LOCATION node FROM day – TO day

CONCEPT (flow, cost, benefit, ratio)

Must be between MIN – MAX

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Optimization STEP 2:Optimization STEP 2:INSTRUMENTS:

1. Select instruments for different NODE CLASSES (demand, supply, reservoir, diversion) from the data base;

2. Assign to specific NODES

3. Configure the specific techno-economic data (efficiency, economics)

INSTRUMENTS:

1. Select instruments for different NODE CLASSES (demand, supply, reservoir, diversion) from the data base;

2. Assign to specific NODES

3. Configure the specific techno-economic data (efficiency, economics)

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Optimization STEP 3:Optimization STEP 3:How it works: the MC optimization

1. Selects COMBINATIONS of INSTRUMENTS, starting with the a priori weights/probabilities;

2. Applies them to the base scenario, as incremental changes

3. Evaluates the consequences (CRITERIA)

4. Compares with all the CONSTRAINTS

How it works: the MC optimization

1. Selects COMBINATIONS of INSTRUMENTS, starting with the a priori weights/probabilities;

2. Applies them to the base scenario, as incremental changes

3. Evaluates the consequences (CRITERIA)

4. Compares with all the CONSTRAINTS

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Optimization STEP 3:Optimization STEP 3:5. Rejects INFEASIBLE solutions6. Retains FEASIBLE solutions as the

starting point for new trials, “learning” to improve the CRITERIA values (genetic algorithms, adaptive heuristics)

7. Continues the trials until:a. The maximum number of trials has been

reached (1000 - 1,000,000);b. The required number of feasible solutions

has been found

5. Rejects INFEASIBLE solutions6. Retains FEASIBLE solutions as the

starting point for new trials, “learning” to improve the CRITERIA values (genetic algorithms, adaptive heuristics)

7. Continues the trials until:a. The maximum number of trials has been

reached (1000 - 1,000,000);b. The required number of feasible solutions

has been found

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Optimization STEP 4:Optimization STEP 4:1. Export the set of FEASIBLE solutions to

the discrete multi-criteria DSS tool (DMC)

2. Rank solutions by individual criteria

3. Plot solutions on plains of two criteria

4. Manipulate PREFERENCES (set of criteria, constraints, reference point) to obtain a preferred (compromise) solution

5. Involve all stakeholders where feasible.

1. Export the set of FEASIBLE solutions to the discrete multi-criteria DSS tool (DMC)

2. Rank solutions by individual criteria

3. Plot solutions on plains of two criteria

4. Manipulate PREFERENCES (set of criteria, constraints, reference point) to obtain a preferred (compromise) solution

5. Involve all stakeholders where feasible.

Decision Support (multi-attribute)Decision Support (multi-attribute)

Reference point approach:Reference point approach:

nadirnadirnadirnadir

utopiautopiautopiautopia

A1A1

A2A2

A3A3

A4A4

betterbetter

efficient efficient pointpoint

criterion 1criterion 1

crite

rion

2cr

iterio

n 2 A5A5

dominateddominated

A6A6

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Finding a compromise solution:Finding a compromise solution:

Direct stakeholder involvement:

• Add or delete criteria

• Introduce (secondary) constraints

• Change the reference point: default is UTOPIA

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Optimization STEP 5:Optimization STEP 5:1. Re-introduce the efficient solution to the

simulation models, re-run2. Test all details of the systems behaviour

and performance to re-assure all stakeholders that THEIR specific requirements are being met;

3. Obtain agreement and consensus on the distribution/allocation of benefits: document the agreement, and have everybody sign on the dotted line….

1. Re-introduce the efficient solution to the simulation models, re-run

2. Test all details of the systems behaviour and performance to re-assure all stakeholders that THEIR specific requirements are being met;

3. Obtain agreement and consensus on the distribution/allocation of benefits: document the agreement, and have everybody sign on the dotted line….

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In summary:In summary:Simulation-based optimization can identify

possibilities for considerable





Simulation-based optimization can identify possibilities for considerable





dss for integrated water resources management (iwrm) simulation based mc optimization ddr. kurt...

Documents

meaningful criteria

multiple criteria

multi criteria optimization

water quality model

system river basin

topological model

entire basin sectorally

subbasin mechanisms