ASSESSMENT OF THE DRAVA RIVER (CROATIA) BY WATER QUALITY INDEX METHOD

摘要

Water quality of the Drava River (Croatia) was evaluated by Water Quality Index (WQI) method. WQI is a single number that expresses the quality of water by integrating the water quality variables. The purpose is to provide a simple and concise method for expressing water quality for different usage. Six important parameters such as pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate (NO_3-N), total nitrogen (TN) and total phosphorus (TP) were included in the calculation of WQI. A research on the Drava River was conducted in 2010, and the results obtained indicate that water quality was in excellent condition (WQI values ranged from 90.4 to 94.5). WQI values were compared with National Sanitation Foundation's Water Quality Index (WQI-NSF) and Pantle-Buck saprobic index (SI). Results indicate better correlation factor with SI which include both macroinvertebrates and phyto-benthos than with SI which include only macroinvertebrates.