Mobesens

WP1 focussed on the identification of systems requirements for different types of water monitoring systems. Two major categories of water monitoring can be founded - laboratory measurements and on-line measurements - with different objectives, but complementary results:

• Laboratory measured values, exhaustive but static. Quite numerous values – concentration of chemical, biological or biochemical species – with a high accuracy but normally with a high preparation and evaluation time. Their use in “real-time” control is limited due to time to get the result.
• On-line in- situ measured values, symptomatic but dynamic. Not so numerous values - due to the complexity of making in automatic mode at a relative low cost – but with enough accuracy and answer time so a real-time system can be implemented. Nowadays, the use of on-line monitoring networks for real-time control of water quality is mainly accepted as the best control system for detecting abnormal situations, with a very low reaction time. Monitoring networks will greatly improve surveillance and control of toxic chemicals in surface water and industrial effluents.

In order to build networks, some requirements have to be taken in account:

• What to measure. The previous acknowledge of water to measure will indicate which quality elements (biological, hydromorphological and physical-chemical) have to be measured, and the state of the art will determine which chemical species can be measured.
• Why to measure, because the requirements are different for having a network for scientific knowledge or for an alert system.
• Where to measure, in order to get a representative sample to analyze.
• When to measure, depending on the water type (river, sea, lake...), and the process time.