Emilia Varadinova

Towards a structured approach to building qualitative reasoning models and simulations

Successful transfer and uptake of qualitative reasoning technology for modelling and simulation in a variety of domains has been hampered by the lack of a structured methodology to support formalisation of ideas. We present a framework that structures and supports the capture of conceptual knowledge about system behaviour using a qualitative reasoning approach. This framework defines a protocol for representing content that supports the development of a conceptual understanding of systems and how they behave. The framework supports modellers in two ways. First, it structures and explicates the work involved in building models. Second, it facilitates easier comparison and evaluation of intermediate and final results of modelling efforts. We show how this framework has been used in developing qualitative reasoning models about three case studies of sustainable development in different river systems.

ASSESSMENT OF ECOLOGICAL STATUS AND PRELIMINARY RESULTS ON REFERENCE CONDITIONS IN ALPINE GLACIAL LAKES (BULGARIA) - A CONTRIBUTION TO THE IMPLEMENTATION OF THE WATER FRAMEWORK DIRECTIVE

ABSTRACT The ‘normative definitions’ of ecological water quality classes given by the Water Framework Directive (WFD) are narrative descriptions of the conditions present in water bodies of different qualities relative to reference conditions found in unimpacted sites. Defining the type-specific reference conditions for water bodies and finding biological metrics that sensitively reflect only the anthropogenic deviations from those conditions are the biggest challenges that the ecological status assessment faces. This study aimed at phytoplankton, macrophyte, macro-invertebrates andfish-based assessment in two high mountain glacial lakes and establishing preliminary reference conditions. The lakes are located in Rila and Pirin Mountains, Southwest Bulgaria. Chernoto Lake is ultra-oligotrophic and has abundant submerged macrophytes; Bezbog Lake is also oligotrophic with submerged macrophytes, both with macrozoobenthic communities typical for oligosaprobic conditions. Sampling was carried out from July to September in 2009 and 2011. The biological and water quality parameters in the lakes are discussed. Indices elaborated in a European context (Algae Group Index, Reference Index, adapted biotic index, Pantle & Bucks saprobic index and German trophic index PETI) were tested on the collected data set. The type-specific taxa for the studied lake type were preliminarily determined.

Water Quality and Ecological State Assessment of the Blagoevgradska Bistritsa River (South-West Bulgaria) Based on Macrozoobenthos Collected by Two Sampling Standards

ABSTRACT Complex investigations of the Blagoevgradska Bistritsa River, left tributary of the trans-boundary Struma River, were carried out in the summer of 2008. Seven representative sites were sampled. Physico-chemical parameters such as water temperature, pH, oxygen concentration, oxygen saturation, conductivity, nitrates and phosphates were measured. The biological assessment was based on macroinvertebrate communities—one of the obligatory biological quality elements according to the Water Framework Directive requirements and the national legislation. Canonical Correlation Analysis (CCA) was used for the explanation of the site-physico-chemical factors relationship. Indices of species diversity (c, e, H), saprobiological index (SR), biotic index (BI) and trophic index (RETI/PETI) were used to determine the water quality and the ecological state of the water bodies. According to the values of the physico-chemical parameters, indices of species diversity and the saprobiological index, the water quality of the sites from the source to the city of Blagoevgrad was I—II category. The ecological state was assessed as high, according to BI and high and good, based on the trophic index RETI. The water quality at the Blagoevgradska Bistritsa mouth, influenced by the waste waters of the city of Blagoevgrad, was assessed as II—III category, and the ecological condition, as moderate and poor (BI) and bad (PETI). The distribution of the physico-chemical parameters at the ordination diagram divided the studied sites into two groups: upstream (clean, unaffected sites) and downstream (anthropogenically influenced sites) of the city of Blagoevgrad. Two periods of investigation (2002–2003 and 2008) and two standard methods for macrozoobenthos sampling (handnet sampling of aquatic benthic macroinvertebrates and quantitative samplers for benthic macroinvertebrates on stony substrata in shallow freshwater) were compared. The results showed that for a five-year period of time changes in the water quality and the ecological state of the studied sites had not been observed. The two sampling methods gave similar results as regards the values of the indices used.