Monitoring Programmes, Multiple Stress Analysis and Decision Support for River Basin Management

Abstract

The identification of plausible causes for water body status deterioration will be much easier if it can build on available, reliable, extensive and comprehensive biogeochemical monitoring data (preferably aggregated in a database). A plausible identification of such causes is a prerequisite for well-informed decisions on which mitigation or remediation measures to take. In this chapter, first a rationale for an extended monitoring programme is provided; it is then compared to the one required by the Water Framework Directive (WFD). This proposal includes a list of relevant parameters that are needed for an integrated, a priori status assessment. Secondly, a few sophisticated statistical tools are described that subsequently allow for the estiation of the magnitude of impairment as well as the likely relative importance of different stressors in a multiple stressed environment. The advantages and restrictions of these rather complicated analytical methods are discussed. Finally, the use of Decision Support Systems (DSS) is advocated with regard to the specific WFD implementation requirements

Assessing the Impact of Multiple Stressors on Aquatic Biota: The Receptor’s Side Matters

“…Which challenges do arise when moving from chemical risk assessment to risk assessment of multiple stressors? A first complication is the fact that chemical, biological, and physical stressors differ in their inherent energy, as well as temporal and spatial scales. − Smaller-scale or local stressors (e.g., chemical pollution) differ from larger-scale stressors (e.g., global warming) in their duration and intensity (Figure ), implying unequal sizes of effects upon species responses, species diversity, as well as ecosystem functioning and recovery. − These differences between stressors in terms of intensity, frequency, temporal, and spatial scales (Figure ) is one of the complicating factors in the assessment of the combined effects of stressors.…”

Setting Priorities in River Management Using Habitat Suitability Models

“…To reduce the number of scenarios that should be tested with water quality models, a crucial first step is something that can be referred to as solution scanning [52]. By first analyzing the system and making a diagnosis [5] of the impairment at hand, river managers can specify a limited set of management options [53] that could be tested in scenario calculations with perhaps more complex water quality models. Due to this, we argue to not only put the ecological models as the last model in an integrated modeling framework, but to use them also as a first step in these frameworks.…”