SEASONAL AND SPATIAL VARIATIONS OF WATER QUALITY FOR IRRIGATION IN BUYUK MENDERES RIVER, TURKEY

Buyuk Menderes basin is one of the most important agricultural basins in Turkey, and the required irrigation water is supplied from Buyuk Menderes River and its tributaries. The water quality of the river for agricultural use has been a major public debate. The aims of this study were to identify and characterize seasonal and spatial variability of irrigation water quality in Buyuk Menderes River together with suitability for irrigation purposes. To achieve these aims, water quality parameters (EC, SAR, Na, Cl, B, NO(3)-N, HCO(3) and pH) monitored by State Hydraulic Works of Turkey (DSI) at 9 sites along Buyuk Menderes River between 1995-2006 were analyzed using appropriate graphical and statistical methods. The results showed that there were significant seasonal and spatial changes among seasons and sites, respectively. Water quality for irrigation purposes was generally high or medium quality. Besides, appropriate cultural practices should be employed for potential salinity and specific ion toxicity problems, especially at middle reaches of the river.