Spatial Assessment of Reservoir Water Quality Using GIS-Based Thematic Mapping: A Case Study of Kesikköprü Dam Lake, Türkiye

Year 2026, Volume: 8 Issue: 1 , 39 - 55 , 30.03.2026

Olcay Gülçiçek Uysal , İlknur Gençoğlu

https://izlik.org/JA87ZB33EW

Abstract

Assessing the water quality of reservoirs used for drinking water supply is essential for sustainable water resource management. This study evaluates the spatial distribution of key water quality parameters in the Kesikköprü Dam Lake, an important drinking water source located in the Kızılırmak Basin, Türkiye. Monthly monitoring data collected from five reservoir stations (R-1–R-5) between April 2022 and March 2023 were analyzed, and annual average values of selected physicochemical and chemical parameters, including electrical conductivity (EC), total Kjeldahl nitrogen (TKN), total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD), biochemical oxygen demand (BOD), arsenic (As), and iron (Fe), were calculated. Spatial distribution maps of these parameters were generated using the Kriging interpolation method within a Geographic Information System (GIS) environment (ArcGIS 10.8). The obtained results were evaluated in accordance with national surface water and drinking water quality regulations. EC values ranged between 1658 and 1735 µS/cm and corresponded to moderate surface water quality while remaining within the A1 drinking water category. Nutrient parameters generally indicated very good to good water quality conditions, although localized increases in TKN suggested potential agricultural runoff influence. Organic pollution indicators (COD and BOD) remained within very good to good quality classes across the reservoir. Arsenic and iron concentrations showed moderate spatial variability but remained within the A2 treatment category, indicating that conventional treatment processes would be sufficient for potable water production. Overall, the results demonstrate that reservoir water quality is mainly influenced by diffuse agricultural pressures and natural geological conditions rather than industrial sources. The integration of monitoring data with GIS-based spatial analysis provides an effective framework for identifying spatial variability in reservoir water quality and supporting basin-scale water resource management.

Keywords

Spatial interpolation , Kriging method , Surface water monitoring , Water quality classification , Central Anatolia Basin

Ethical Statement

The authors declare that there is no violation of research and publication ethics in this study.

Supporting Institution

The authors declare that there is no violation of research and publication ethics in this study.

Thanks

This study was conducted within the scope of the “Kesikköprü Dam Basin Protection Plan and Special Provision Determination Project” commissioned by the Ankara Metropolitan Municipality Water and Sewerage Administration (ASKİ), with contributions from DOKAY Engineering.

References

• Al-Taani, A. A., El-Radaideh, N., Al Khateeb, W., & Al Bsoul, A. (2018). Assessment of water quality in surface water reservoirs using GIS and multivariate statistical analysis. Environmental Monitoring and Assessment, 190, 1–16. https://doi.org/10.1007/s10661-018-6976-9
• Atıcı, A. A., Gültekin, A., Şen, F., & Elp, M. (2016). Erciş (Van) ilçesi içme sularının su kalitesi özellikleri. Yüzüncü Yıl Üniversitesi Tarım Bilimleri Dergisi, 26(4), 517–528.
• Cebe, K., & Gülçiçek Uysal, O. (2024). Kesikköprü Baraj Gölü havzası yayılı kirlilik kaynaklarının ve kirlilik yüklerinin tahmini. Niğde Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi, 13(1), 253–261. https://doi.org/10.28948/ngumuh.1355285
• Enas, A. T. E. A., Kadak, A. E., & Sönmez, A. Y. (2017). Germeçtepe Baraj Gölü’nün (Kastamonu–Daday) bazı fiziko-kimyasal su kalite parametrelerinin incelenmesi. Alinteri Journal of Agriculture Science, 32(1), 55–68
• Gülçiçek Uysal, O., & Cebe, K. (2024). Determination of effects of point pollution sources in Kesikköprü Dam Lake Basin. Gazi Journal of Engineering Sciences, 10(1), 84–101. https://doi.org/10.30855/gmbd.0705N07
• Mete, B., Karadeniz, G. E., Bayram, A. (2024). Water Quality Assessment of the Erfelek Dam Lake in the Context of Drinking Water Treatment Plant, Sinop Municipality, Northern Türkiye. The Black Sea Journal of Sciences, 14(4), 2082-2102.
• Mutlu, E., & Aydın Uncumusaoğlu, A. (2016). Physicochemical analysis of water quality of Brook Kuruçay. Turkish Journal of Agriculture – Food Science and Technology, 4(11), 991–998.
• Öztürk, B. Y., & Akköz, C. (2014). Apa Baraj Gölü (Çumra–Konya)’nün su kalitesi ve PCA analizine göre değerlendirilmesi. Biyolojik Çeşitlilik ve Koruma, 7(2), 136–147.
• Selek, Z., & Pınarlık, M. (2019). Yeşilırmak Havzası Çakmak Barajı rezervuarındaki sediment birikiminin araştırılması. Politeknik Dergisi, 22(3), 715–721.
• SYGM. (2016). İklim değişikliğinin su kaynaklarına etkisi projesi: Nihai rapor. Su Yönetimi Genel Müdürlüğü.
• Taş, B. (2011). Gaga Gölü (Ordu, Türkiye) su kalitesinin incelenmesi. Karadeniz Fen Bilimleri Dergisi, 1(3), 43–61.
• Tepe, R., & Kutlu, B. (2019). Karkamış Baraj Gölü (Gaziantep) su kalitesinin incelenmesi. Turkish Journal of Agriculture – Food Science and Technology, 7(3), 458–466. https://doi.org/10.24925/turjaf.v7i3
• Tezce, G. (2010). Drinking water quality in Ankara: A monitoring study (Master’s thesis). Middle East Technical University. https://open.metu.edu.tr/handle/11511/20176
• Thirunavukkarasu, O. S., Viraraghavan, T., Subramanian, K. S., Chaalal, O., & Islam, M. R. (2005). Arsenic removal in drinking water—Impacts and novel removal technologies. Energy Sources, 27(1–2), 209–219. https://doi.org/10.1080/00908310490448271
• Wei, X., Gao, X., Huang, J., & Gao, L. (2020). Exploring the effect of basin land degradation on lake and reservoir water quality in China. Journal of Cleaner Production, 268, 122249. https://doi.org/10.1016/j.jclepro.2020.122249