Hannu Kokko, Vaisala Oyj - Helsinki - Finland

The rapid development of information and sensor technology and high integration of electronics and data communication have made automation of meteorological and hydrological networks increasingly affordable and attractive to Meteorological and Hydrological Services and other users, who need real-time weather monitoring and management of water systems such as rivers, lakes, reservoirs and ground water. Hydrometeorological networks, typically consisting of a large number of automatic monitoring stations, telecommunication systems, databases and application software for the users, are installed in a wide geographical area, often in remote locations. Capable of surviving harsh weather conditions, they provide valuable information on a large variety of weather parameters, precipitation, water quality and existing water reserves helping the authorities to make right and on-time decisions. On the other hand there is all the time increasing demand on volume of meteorological and hydrological data due to requirements derived from legislation, environmental awareness and efficiency in many industrial sectors of our modem society. Nowcasting, including floods and severe weather events, adds its requirements for real-time monitoring.

Telecommunication and management of large databases form the main part of the total operating cost of these networks. For severe events, the reliability of the monitoring equipment and telecommunication are the most important selection criteria. Multi-telemetry systems offer the means to optimize the communication cost, extend the network even to most remote places and secure the continuos availability of critical monitoring data under all circumstances.

Operating of large-scale networks is always an economical burden. The majority of the Total Life Cycle Cost (TLCC) is generated by maintenance, calibration and update/upgrade cost. Meteorological and/or hydrological network should not be used on their own. In many cases the same infrastructure can serve several users and applications as well. Complementary meteorological and climatological observations in the hydrological network can frequently be made in order to produce timely and accurate local forecasts, warnings, reports and other end products for network owners as well as to third party customers. Therefore, the economies of scale will offer a solution for controlling the TLCC cost.

This paper will provide the description of a flexible and integrated monitoring and data management system from sensor to databases. The paper also describes new integrated sensors with increased reliability and accuracy. All these features are offering significant savings in setting up and in the operating cost of a modern and always up-to-date monitoring network.