Characterization of groundwater and surface water interaction in kirmir stream using thermal remote sensing and in-stream measurements

Varlı, Dilge
Effective management of water resources requires understanding and quantification of interaction between groundwater and surface water bodies. The exchange processes have recently received increasing attention because also they have important influences on ecological status of watersheds. The purpose of this study was to characterize the interaction between surface water - groundwater in Kirmir stream - a controlled stream nearby Kızılcahamam, Ankara, Turkey. At the first stage, stream reaches with interaction of groundwater – surface water potential were identified using geological information. Then, thermal remote sensing was utilized to further pinpoint the potential locations in which interaction could occur at a smaller scale. Nested piezometers were installed in identified locations to observe the variations in vertical hydraulic gradient over time. Discharge measurements were performed to understand the gains and losses in stream discharge. Streambed temperature measurements were taken at two different depths for a period of time using temperature loggers to calculate the vertical fluid fluxes through the streambed at various locations. Basic water quality field parameters (temperature, electrical conductivity, total dissolved solid amount, dissolved oxygen, pH and oxidation - reduction potential) were measured. Water samples were taken from both stream and piezometers and these samples were analyzed for major anion concentrations. Chloride mass balance was performed to find the contribution of groundwater and chloride concentrations were associated with the geology of the area. This hierarchical, multi-scale methodology provided an efficient and effective way to determine the locations and the direction of groundwater and surface water exchange processes within the study area