WATER QUALITY PARAMETERS IN RELATION TO LAND COVER IN THE GALYAN WATERSHED, TRABZON

摘要

The Galyan-Atasu Dam was constructed in order to supply water for the drinking, utility and industrial needs of Trabzon and its surrounding areas. There is a significant relationship between the land cover (LC) and the quality of the surface water of the streams that supply the dam. This study was conducted in order to present the impacts of LC on water quality parameters. Within this scope, a total of eight subwatersheds having low anthropogenic impact were chosen from amongst the upper watersheds of the Galyan and ?im?irli streams, which supply Galyan-Atasu Dam. The granite bedrock of Ka?kar granitoid form outcrops in the subwatersheds. Land cover (coniferous forest, broad-leaved forest and grassland) ratios were determined with the help of Quick-Bird satellite imagery. Over the time period of 2010 - 2011, water samples were collected and analyzed for a number of water quality parameters in order to investigate their spatio-temporal variability particularly in relationship to the LC. Analysis of variance (ANOVA) indicated significant spatial variability in pH, EC, TN, Ca+2, Mg+2 and K+ across the basins. Correlation and regression analyses of the average values of the water quality parameters and LC patterns revealed that grassland was significantly correlated with T and TN, coniferous forest with TP, Ca and Na, and broad-leaved forest with TN, TP, Ca and Na. This research could provide critical information on sustainable land cover for the dam watershed and for application in water resource conservation.