Implementing integrated and systems approaches to water quality management considering data uncertainty

The paper emphasises the need for a system analysis approach at all scales in a water system considering all elements, subsystems and their interactions. In order to support this process in developing countries, the paper presents best management practices of monitoring and regulation of water resources. Furthermore, it recommends the integration of the modelling, decision and information support tools with the corresponding monitoring practices, regulatory instruments and management activities in a closed-loop cycle. Estimation and implications of monitoring data uncertainties are illustrated by two case study examples based on water quality monitoring data in the Southern African region. One is related to compliance with regulatory instruments and the other to pollution load assessments. Implications of monitoring data characteristics and uncertainty are discussed. Considering the conditions in developing countries, characterised by shortage of resources and lack of data, the application of adaptive management and modelling strategies in the water resources management practice is recommended.