Abstract
Anthropogenic activities and climate change are the important factors
adversely affecting water resources in Kucuk Menderes Watershed. The
watershed is shown as a water-stressed watershed due to increasing
population and uncontrolled groundwater use. Water resources management
within the watershed has become a challenge and to overcome this
challenge, modeling studies are necessary. In this study, a hydrologic
model for the watershed was established using SWAT (Soil and Water
Assessment Tool). The model calibration and sensitivity analysis were
performed by SWAT-CUP (SWAT-Calibration Uncertainty Programs) using
Sequential Uncertainty Fitting Version-2 (SUFI-2) method. The model was
mostly sensitive to CN2 parameter. Soil and groundwater parameters were
the parameter categories that the model was mostly sensitive. The
performance of the model was evaluated with P- factor, R- factor and
objective functions. P- factor values for the calibration were in the
range of 42-75 % meaning that the monitoring data were matched by the
model within this range. According to the objective functions, the model
performance was evaluated as good and satisfactory based on gauge
stations. As this study is one of the first watershed modeling studies
for the watershed, it will contribute to different studies to be done in
water resources management. The results of this study could serve as a
basis for a wide range of studies in the watershed such as water budget
determination and sectoral water allocation, impact of climate change,
future water quality modeling studies and understanding the impact of
best management practices applications to prevent further deterioration
in water quantity and quality within the watershed.