New challenges in lake and river monitoring

Today, the problems posed by the shortage of water and continuingpollution demand more effective ways of monitoring and managing ourlakes and rivers. In Europe, the statutory requirements of the WaterFramework Directive (WFD) make further demands on our collectiveexpertise and require a sound understanding of the processes that regulatethe dynamics of aquatic systems. Freshwater ecosystems are highlydynamic and change on time-scales that range from a few hours to severalmonths. The development of models that simulate these processes is oftenhampered by the lack of sufficient data to parameterize the processes andvalidate the models. In this article, I review some of the challenges posedby this lack of information and suggest ways in which they can be met byusing automatic monitoring systems of the kind described by Rouen et al.(2005, this volume). The examples are drawn from recent modellingstudies in semi-arid regions. One of these studies is the project tempQsim(EVK1-CT2002-00112) funded by the European Commission. In thisproject, detailed field and model analyses have been performed at eightcatchment study sites in south and south-east Europe. A number ofperceptual models for the study sites have been established, and results arebeing used to improve selected catchment models and provide a moreadequate description of pollution dynamics (e.g. Tournoud et al. 2004,Tzoraki et al. 2004). Results from the extensive field studies and modeltests are now being used to derive recommendations for more tailoredmonitoring concepts in highly dynamic, but ‘data scarce’ environments,such as are frequently found in Mediterranean river basins