Determination of water quality properties of Kahta Stream (Adıyaman) discharging into Atatürk Dam lake

This study was carried out to determine water quality of Kahta Stream discharging into Atatürk Dam Lake by means of some physico-chemical parameters and epilithic diatoms. For this purpose water samples and epilitic diatom specimens were collected monthly from five sites selected from upper part towards to lower part of the stream between April 2012 and March 2013. Temperature, conductivity, total dissolved solids, total suspended solids, turbidity, pH, dissolved oxygen, total hardness, total alkalinity, calcium, magnesium, chloride, total nitrogen, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, total phosphorus reactive phosphate-phosphorus, dissolved silica, sulfate and chemical oxygen demand and species composition of epilithon and abundance (as biological parameters) were defined seperately. The results of the present study yielded that all five stations were III. Class (polluted water) with regard to total phosphorus and nitrite whilst stream water was found to be I.Class (high quality water) in terms of other parameters according to Surface Water Management Guide-Inland Water Resources Quality Criteria. During the study 57 epilithic diatoms taxa in 26 genus were identified; of all, three taxa were centric whilst 54 taxa belonged to pennate diatoms. Generally Achnanthidium minutissimum, Achnanthidium rivulare, Cymbella affinis, Cymbella cymbiformis, Cocconeis placentula var. euglypta and Gomphonema olivaceum were recorded as dominat diatoms. Saprobi Index (SI), Trophic Diatom Index (TDI), Trophic Index (TI), Swiss Diatom Index (DI-CH) and Generic Diatom Index (GDI) were used in order to determine water quality of Kahta Steram. Data of indices SI, TDI, TI and GDI showed that all stations have I-II. water quality whilst III. Class water quality was found according to DI-CH. Margalef (d), Shannon (H') and Simpson (D) Diversity Indices were employed in order to determine the diatom diversity and all three indices yielded that the highest diversity index was at third station.