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The current practice consists in complementing the usual online monitoring systems made of fixed monitoring stations with few mobile units, installed on boats. Fully automatic kinematic monitors can be installed on whatever boat fleet travelling over the monitored area, e.g. for public or private transportation. In the Lagoon of Venice, boats employed for normal waste collection and cleansing service were successfully utilized. Using regular service boats can make the systematic acquisition of some key variables representative of water quality and circulation a much easier task with lower associated costs.
Usually, a dedicated laboratory boat with specialized monitoring equipment is also necessary, in order to allow specific in-situ analyses and checks, particularly in case of anomalous situations or real-time monitoring in case of accidents.
It is worth to underline that the possibility of examining a whole ecosystem, continuously yelding a huge amount of low-cost data, and the ability of reaching whatever position in order to monitor local phenomena, changes de facto the whole scientific and methodological approach to the problem. This generates the innovative aspects of the proposed approach.
The suitable real-time sampling rate for physical-chemical data is 10~120 sec, on the basis of the size of the monitored area and of the expected spatial gradients of monitored variables. Biological samples, if included in the monitoring protocol, are usually taken on seasonal basis, depending upon growth and reproduction cycles.
The final element of the environmental data acquisition chain is an Environmental Database. This structure includes both the measurement data coming from the water body and the scenario description data (cartographic, anthropical, geo-morphological) concerning the territory.
In order to turn the raw monitoring data (oxygen concentration, turbidity, temperatures, presence of larvae.) into immediately understandable information (e.g., “in these conditions a sudden anoxic crisis may occur”), it is necessary to develop a set of interpretation and forecast models describing the behaviour of the environment. Such models typically consist in mathematical relationships (analytical, statistical, matrixes) between the measured environmental variables and other variables whose short and long-term trend is to be evaluated or estimated.
One commonly used software package is e.g. WATERNET modelling tool, cofinanced by the European Union. Such modelling tools make a more efficient and effective use of monitored data: modelling a river, forecast the evolution of a pollution event in real time, generate custom-made reports, and calculate quality indices.