Assessment of Discharge Trend of Kasilian Watershed

change can affect changes in mean annual and seasonal discharge, magnitude and frequency of flood and drought. These factors influence agricultural water management ecosystems. For this propose, Kasilian catchment in Khazar region was selected for study. Daily and monthly discharge time series during 1334-89 are reviewed. After reconstruction, eight discharge indicator including Q5‌, Q10, Q30, Q50, Q70, Q90, Q95, Qmean were prepared for further analysis. Three methods of Thiel-sen, plot on Cartesian coordinate system and Mann-Kendall method were employed. Result show although Theil-sen method is suitable for determining discharge trend value, but Mann-Kendall method is a more suitable approach for significant and time of trend. The results of Mann-Kendall method show highest decreasing trend of both high and low discharge belong to winter, spring, autumn and summer, respectively. Discharge indicator of Q90, Q95 only showed a positive trend in winter. In most seasonal and annual discharge indicators’ changes in decreasing or increasing trend were experienced during 1370-74 showed a constant rate. Plot on Cartesian coordinate system as a simple and suitable method for determining low, medium and high time series is used.