Multivariate statistical and spatial assessment of water quality from a dam threatened by drought at the mid-Anatolia, Cappadocia/Turkey

Tatlarin dam lake is an important watershed of the Central Anatolia (Cappadocia) Region, which has experienced the effects of global warming on a large scale in recent years. The aim of this research is to investigate all the environmental factors involved in the pollution of the lake and to reveal the dam water quality comprehensively in terms of irrigation and other uses. In this context, the water quality of the dam under drought and eutrophic threat was evaluated integrated with multivariate statistical and spatial analysis. In addition, the current trophic status of the reservoir was determined. In the study, seasonal changes on the ecological structure were examined with national and international quality indeces, the trophic state index (TSI), and trophic level index (TLI). Field studies were conducted in the reservoir for four seasons (2017–2018), and the collected surface water samples were analyzed according to standard methods. The annual averages of total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (COD), and total organic carbon (TOC) concentrations, which are indicators of excess nutrient input, were determined at 0.79, 3.91, 61.60, and 5.72 mg/L, respectively. The measurement results showed the presence of significant amounts of anthropogenic pollution throughout the lake. Periodic findings observed from distribution maps created with ArcGIS revealed significant changes in trophic level due to the effect of contaminated lake water and measures for reducing eutrophication should be taken rapidly.