Determining the number of stations to monitor rivers’ water quality considering environmental, technical, and economic criteria (Case study: the Gedarchay River)

Increasing the number of water quality monitoring stations and conducting multiple sampling is one of the measures to improve the productivity of river water quality control operations. The figures must be determined by scientific methods so that the system dynamism can be explained. Increasing rivers pollution, which sometimes oversteps the self-purification limitation of the rivers, causes great damage to the environment. In the present study, while modeling the behavior of the river in the conditions of effluent entry whether point or non-point, multiple criteria decision-making method (AHP) was conducted to prioritize monitoring operations at river stations. For this purpose, the Gedarchay River was chosen as a case study. Based on the WQI results, water quality parameters rose alongside the river with rural sewer flowing. As such, stations 7 and 8 in scenario I showed moderate quality due to increased pollution loading while other stations and by extension the other scenarios indicated good to excellent figures. Considering water quality monitoring operations (), the existing stations were prioritized. The weights of the main criteria were determined as follows C1 = 0.483, C2 = 0.157, C3 = 0.272 and C4 = 0.088, and the stations 1-8 were weighted respectively 5.1, 7.9, 8.6, 16.6, 16.3, 17.5, 16.2 and 12.0, confirming the importance of station 6 in getting prioritized.