Revelation and Comparative of Rainfall and Discharge Cycles of QalehRoudkhan and Navroud Basins

Humans have been the main cause of climate change, ignoring the laws of nature and the lack of understanding of the environmental issues associated with it. The Clear and hide cycles of climate change are also affected by climate change. The appearance and occurrence of these fluctuations can play an important role in the creation of environmental crises and their identification in environmental planning. Therefore, in the present study, hide, slow and gradual cycles for rainfall and discharge time series with a statistical period of 38 years (1966-2005) at seasonal scale in both Navourood and QalehRudkhan basins in Guilanprovince through spectral analysis technique and analysis of chronographs at 95% confidence interval was identified and compared. The results of this study indicate that in Navroud basin for both parameters, cycles are significant and follow different sinusoidal cycles. However, the non-sinusoidal cycle has not been seen in the QalehRoudkhan basin. The change of discharge in the Navaroud basin is more than rainfall, but the non-sinusoidal cycle (trend) of discharge in the GhalehRudkhan basin is more apparent than seasonal rainfall.