WaterWare description Data management, Objects Monitoring, time series Hydro-meteorological data, forecasts Rainfall-runoff: RRM, floods Irrigation water demand Water budget modelling Water quality: STREAM, SPILL Multi-criteria optimization, DSS User support, system maintenance

IWRM, optimization Water Management Problems: Too much, not enough, Wrong time and place Insufficient quality Poor efficiency, economics Growing uncertainty Information requirements: How to make sure we get all the water we want when we want it, cheap, reliable, sustainable ?

Decision Support Systems Manage preferences: criteria, objectives, constraints Design/manage alternatives simulate alternative strategies Select best (compromise) solution BUT: Preferences vary; multiple criteria, conflicting objectives; Uncertain effects, uncertain driving forces: future demographics, economy, technology, CLIMATE

IWRM optimization We do NOT want water as such, we want water based products and services: Increase the efficiency, reduce specific water needs, costs ? MAXIMIZE net benefit from water allocation/use considering socio-economic and environemntl criteria

everybody is better off ! Paradigm change: NOT about “supply, access, ecological status” Shared “benefits”: Increasing overall net benefit while meeting individual user constraints as the basis for win-win solutions: everybody is better off !

Paradigm change: Replace OPTIMAL with Good enough, but robust New concepts: Robustness, reliability, resilience, sustainability

robust solutions, reliable benefits: Paradigm extension: robust solutions, reliable benefits: Increasing overall net benefit while meeting individual users constraints as the basis for win-win solutions under growing uncertainty: Include reliability, sustainability, as explicit criteria of optimization.

Design alternatives: Assign alternative technologies (emission control, water savings from the data base) to emission sources, water users, structures: calculate emission reductions, increase of efficiency, costs and benefits for thousands of combinations  optimization

WaterTechnology, examples of water saving devices increasing water efficiency

Large scale photovoltaic desalination plant (combined water saving/substitution and emission control technology)

Irrigated Crop Data Base: provides input data for the supplementary irrigation water demand model

Water technology data base: irrigation technology

Water technology data base: irrigation technology

Allocating water technologies to the (demand) nodes

Optimization strategy: Vary the assigned technologies, Monte Carlo, then heuristic, machine learning, genetic algorithms, …. to convergence Separate feasible and infeasible solutions (constraints) Extract pareto-optimal subset (non-dominated), criteria selection, reference point (UTOPIA) Select efficient “best” solution

Setting (sectoral) constraints for an optimization scenario

OPTIMIZATION: ranking list of alternatives, ranking by user selected criteria

Optimization result details: results by criteria, basin wide

Decision Support (multi-attribute) Reference point approach: utopia A4 efficient point A5 A2 criterion 2 A6 Reference point method: feasible and non-dominated alternatives are plotted on plains of pairs of criteria, the distance to UTOPIA (or a reference) measures in a normalized N (number of criteria) dimensional space; users can select critiera to consider, introduce secondary constraints, and move the reference. dominated A1 A3 better nadir criterion 1

Example screen from the web based DSS, WaterWare scenario; users can toggle criteria ON/OFF, define secondary constraints, select pairs od criteria for display, move the reference point, set display options.

Example screen from the web based DSS, WaterWare scenario

control, mitigate, adapt Summary: Define “clearly” what we want (measurable criteria) Identify possible instruments, policies Generate large numbers of feasible solutions, different scenarios of change Find solutions that are FEASIBLE for all scenarios of (climate) change = robust and flexible Strategies: control, mitigate, adapt