فرزانه یزدان پناه قرایی

Every year, the occurrence of heavy rains in the flood-prone basins of the country leads to the occurrence of floods and the resulting damages. Therefore, accurate prediction of rainfall is of great importance to take preventive measures. Therefore, rainfall forecasting is one of the most important issues in the field of water resources management. So far, various methods have been used to predict rainfall. Advanced hydrological research in short-term weather forecasting is uncertain and its impact is still being investigated and understood. The concept of connecting the hydrological model (WRF-Hydro) with the atmospheric model (WRF) is expected to reduce the uncertainties related to the spatial and temporal distribution of storm events, especially for areas with complex characteristics.In this study, the WRF/WRF-Hydro model was evaluated in order to predict 4 rainfall events that resulted in floods. In precipitation simulations, this model was underestimated and the model provided better results in coupled mode. ERA5 data was used to run the model, and these data had a good performance for the model in the mentioned field. Also, Lin, Thompson, and WSM6 were used to configure the model, and according to the error evaluation criteria of RMSE and NSE, all three of these schemes performed similarly.

Rivers play an important role in the economy and agriculture, but climate change and improper management have affected these resources. In order to better manage rivers, it is necessary to know their discharge trend and the factors that create the trend. The severe decrease in rainfall and the resulting dry periods have many negative effects on water resources. The continuation of droughts is a consequence of climate change. This study investigates rainfall and discharge changes in the Aras catchment located in the northwest of Iran. For this purpose, after data validation, 9 hydrometric stations and 5 rain gauging stations were selected with the statistical period of 1987-2016. The purpose of this study was to evaluate the trend of time series variations of precipitation and discharge variables using Mann-Kendall and Sen’s slope estimator tests. The results of the trend analysis showed that precipitation at two stations increased, however other stations did not experience any trends. Furthermore, there has been a downward trend in the discharge trend analysis at the six stations and no trends in the other three stations.