FUZZY-BASED ECOHYDROLOGICAL MODELING FOR IMPLEMENTING THE EU WFD

摘要

Ecohydrology is a scientific area that deals with both hydrological and ecological processes and their interactions. Modeling these processes is characterized as a complex task due to associated uncertainties and nonlinearities. Many of the ecological processes are ill-defined or qualitatively described, sharp knowledge is rather exception. Heterogeneity and variability are main characteristics of hydrological parameters. Unfortunately, traditional mathematical models often fail to cope with the mentioned difficulties. According to the European Union (EU) Water Framework Directive (WFD), the actions to be taken for ecosystem improvement should enable reaching good ecological status for all waters in Europe before 2015. This adds the development time and cost of our models as additional difficulties to the ecohydrological modeling process, since the implementation of the EU WFD requires to afford many reliable ecohydrological models in a limited time space. Fuzzy logic offers potential enhancements to ecohydrological modeling as well as many other scientific areas. It facilitates describing complicated, uncertain and non-linear processes in a strict mathematical framework as well as transforming available experts' knowledge into rule-based models with less efforts and low cost. The basic principals of fuzzy ecohydrological models are illustrated in this paper. The advantages of using fuzzy-based models as tools for implementing the EU WFD are discussed. The paper introduces also a demonstration example for a fuzzy fish-habitat model. The model shows that fuzzy logic is a reliable technique for representing many ecohydrological processes and encourages researchers to carry out further similar research.