Elyas Parvaresh; Rasol Mahdavi; Arash Malekian; Yahya Esmaelpour; Arashk Holisaz
Abstract
Exact estimation of flood-water peak discharge and prioritizing the flooding potential in subwatersheds in main watersheds is necessary (because of cost, watershed restoring is not practicable in all subwatersheds), moreover flood may occur only in some specefic subwatersheds. This study was conducted ...
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Exact estimation of flood-water peak discharge and prioritizing the flooding potential in subwatersheds in main watersheds is necessary (because of cost, watershed restoring is not practicable in all subwatersheds), moreover flood may occur only in some specefic subwatersheds. This study was conducted in Sarkhoon watershed of Bandarabbas (South of Iran) with the aim of developing a flood prioritizing method in small catchments. The resarch was carried out using ElectreIII and Fuzzy Topsis methods belonging to multicriteria models. For the analysis, 7 criterions were selected that includes: Basin mean weight slope, gravilus coefficient, permeability, runoff coefficient, shape coefficient, vegetation cover and rainfall intensity with 25, 50 and 100 years return periods. Then the criterion weights were determined using AHP method and for selecting the best hierarchy and function of electre III and Fuzzy Topsis, the spearman coefficient were utilized and the results showed a correlation coefficient of 0.8 between predicted and actual flood peak values. In the final step the combination method for the final prioritizing was adopted. Results showed that subwatersheds 18-1-1, 14 and 18-1-2 have more flooding peak. It was concluded that the combination method can promise as a suitable method for prioritizing the flooding potential in subwtersheds.
Ommolbanin Bazrafshan; Azimeh Chashmberahm; Arashk Holisaz
Abstract
Evaporation is one of the most important and effective factors in water resources planning and management in arid and semi-arid areas and examining it's changes in time scales and different years as one of the most important climatic parameters, has an important role in planning and water resource management ...
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Evaporation is one of the most important and effective factors in water resources planning and management in arid and semi-arid areas and examining it's changes in time scales and different years as one of the most important climatic parameters, has an important role in planning and water resource management in agriculture section and determining cultivation pattern and proper water resource management. One of the methods to assess and forecast changes in evaporation is time series models by the generic name of ARIMA models. Therefore, in order to determine the best model to predict pan evaporation, after considering the climate using improved Domarton climatic classification method, in each climatic sample, one evaporation station was selected and standardized pan evaporation index (SPEI) was calculated for each of the stochastic model for estimation the amount of future monthly time series SPEI in the period of 1954-1955 to 2009-2010 over the next 12 months. Results showed that the Auto Regressive Moving Average model (ARMA) and Auto Regressive (AR) had the best performance, in Hormozgan province, so that, in the hot and dry, hyper hot arid and hyper hot hyper arid climates, in the next month, had the highest standard coefficient of determination (R) of 0.83, 0.71, 0.7 and the lowest value RMSE of 0.59, 0.8, 0.88, respectively and the AR model was able to predict the next 11 months, well. The results showed that AR model has better performance compared to ARMA model in estimating monthly pan evaporation in hot and dry climates in coastal wilderness areas.
Ahmad Nohegar; Arash Malekian; Majid Hosseini; Arashk Holisaz; Edris Taghvaye Salimi
Abstract
Two factors of cost and time are related directly to the accurate estimate of runoff in the watersheds. More detailed information on the status of rainfall runoff also facilitate decisions on future programs for watershed managers, a step towards the preservation of natural resources for sustainable ...
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Two factors of cost and time are related directly to the accurate estimate of runoff in the watersheds. More detailed information on the status of rainfall runoff also facilitate decisions on future programs for watershed managers, a step towards the preservation of natural resources for sustainable development. In this study, in order to achieve optimal amount of runoff in the Shafaroud watershed, first significant rainfall data of four stations during 1998 to 2011 were collected and combined with other maps of the study area, such as DEM, land use and soil as input data in the form of SWAT model was software. After running the model, the SUFI-2 and GLUE algorithms in SWAT-CUP program used to evaluate the data uncertainty and the most accurate simulation. The first three years (1998-2000) of rainfall data for warm-up and the next 7 years (2001-2007) for the calibration and final 4 years (2008-2011) were used for the validation. Finally, with multiple simulations, the uncertainty of the parameters assessed with P-factor, R-factor, and NS coefficients. The results indicated in runoff simulation, the SUFI2 algorithm ( =0.85, NS=0.74) is more accurate than GLUE algorithm ( =0.82, NS=0.71).
