| Abstract [eng] |
Water Framework Directive is the major legislation in the EU in the field of water policy. It‘s objective is to ensure a good water quality. To acheive this task, every EU country must also establish reference conditionsin Lithuanian rivers. Reference conditions are described from an aggregate of data best acquired from multiple sites with similar physical dimensions, represent minimally impaired conditions, and provide an estimate of natural variability in biological condition and habitat quality. Having established reference conditions, the guide will appear, according to which rivers will be devided into different quality classes, like very good quality, good quality, moderate, ect. The objective of this work is to establish reference conditions in Lithuanian rivers, using national river monitoring data for the year 2005, with three different techniques. The most reliable technique is distinguished. Derived reference conditions were compared with parallel values, evaluated by the Institute of Ecology of Vilnius university. There were main problems defined, while deriving reference conditions, like too small sample, lack of data on hazardous substances. The latter issue is discussed more detailed. |
