Author/Editor		Smolar-Žvanut, Nataša; Krušnik, Ciril; Kosi, Gorazd; Vrhovšek, Danijel
Title		Uporaba perifitona in večjih vodnih nevretenčarjev pri določanju ekološko sprejemljivega pretoka na reki Rižani, Slovenija
Translated title		The use of periphyton and macrozoobentos in determination of ecologically acceptable flow for the Rižana River, Slovenia
Type		članek
Source		Acta Hydrotech
Vol. and No.		Letnik 21, št. 35
Publication year		2003
Volume		str. 129-44
Language		slo
Abstract		The only major spring in the Slovenian Istria is the karst spring of the Rižana River, which is the most important source of water supply for the Slovenian coastal area. In summer months the natural flow is very low, whereby part of water drains off into the underground and several tributaries of the Rižana River dry up. At the same time, the need for water supply and irrigation are at their highest. In the period from 1995 to 1996, the list of all water users and the inventory of polluters were made. From source to mouth of the Rižana River, the hydrological analyses were carried out. The river ecosystem was evaluated according to analyses of periphytic algae and macroinvertebrates on different sections of the Rižana River. Because of large water abstraction and pollution of the river, changes in diversity of macroinvertebrates, in diversity of periphytic algae and in periphyton biomass (ash free dry weight (AFDW), dry weight (DW), chlorophyll a (chl a)) were established. Based on saprobiological analyses, the river is classified as quality class I-II. The evaluation of quality based on BMWP score system and EBI, indicated a deterioration of the aquatic environment in lower parts of the river. In order to maintain the ecological balance, the ecologically acceptable flow (EAF) was determined according to the ecological method for summer months.
Descriptors		FRESH WATER WATER POLLUTANTS ECOSYSTEM PLANTS BIOMASS ALGAE INVERTEBRATES