Water is essential to our planet, useful and used by all living species, mainly freshwater. However, the latter is a scarce resource and therefore its control is an essential and necessary issue.

Freshwater management can be done in different ways and at different scales:

• Management of waterways for shipping
• Management of irrigation canals for agriculture
• Management and optimization of water for industry
• Treatment of wastewater
• Management of flows upstream (catchment)
• Management of river systems
• Simulation of hydrological changes
• Awareness of people to the problem and the scarcity of this resource
• Inequalities in access to safe drinking water between regions and countries

While most of these points are treated for decades, the fact remains that water losses are greater than 50% due to aging or no existing facilities, but mostly due to the fact that it is a very complex problem and the ins and outs are difficult to control.

For proof, the calculations of maritime flows for weather predictions are so far an open issue as consideration of the full model is difficult both theoretically and numerically. Many simplifying assumptions are made and make sometimes obsolete the result, as we can see every day.

However, improvements are done every day and the predictions are better each time.

There was another 50 years, a lot of water networks were managed manually, involving huge losses, but also a lot of damage.

For over 10 years, new techniques are used and created to address more accurately the various above problems and reduce water losses and waste:

• Creation and automation of water systems: automation of the free surface water lines and / or under pressure (autonomous and automatic management of locks on waterways, valves on the rivers to prevent floods and floods, improvement Traffic in sewers …)
• Improved handling of water, increasing yields, new processes of sedimentation and degradation of waste
• Predictions and simulations of weather
• Predictions and simulations of watersheds, and deltas, in one case to set up a hard structure to channel and direct the flow, in the second case to avoid floods and all phenomena degrading the environment (flora and fauna , equipment)
• Improved robustness of the controllers
• Detection and diagnosis of the defaults
• Concatenation of different processes along the water cycle

All this is a necessary approach and Hydraulic Research is a major asset. Lower losses in closed waters networks is particularly significant but cannot be applied to all cases.

Decontamination process control of wastewater is also a promising route which all the potential is not exploited. This requires a better understanding of the phenomena involved (simulation) and control reactions. All this can nevertheless not be decoupled with a strong awareness of each of us that we are wasteful and inequitable access to this resource between human beings themselves and the different species.

Article provided by
Valérie Dos Santos Martins
Laboratoire d’Automatique et de Génie des Procédés, Université Claude Bernard Lyone
IFAC Technical Committee 2.6. Distributed Parameter Systems