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Volume 16, Issue 42 (9-2016)
Abstract
In this research, impacts of climate change on the streamflow hydrological status of the Arazkooseh River are discussed. After Calibration and validation of the LARS-WG, HadCM3 was downscaled under A2 Scenario in three climatology station. Beside, calibration and validation of the SWAT model were done by observed data relative to past period of times. Streamflow values are then predicted using climatic parameters of period of 2011-2030, 2046-2065 and 2080-2099 years via SWAT model. The results indicated that the average annual temperature will increased around 0.8, 1.2 and 4.9 °C in desired periods, respectively. Precipitation values will increased 8.8 and 11.2 percent in the early and mid- century and it will decreased with 7.8 percent in the last years of century, correspondingly. The peak of rainfall will moved from month of March to the December. Because of climate changes, streamflow will increase 13 and 5 percent in the near periods. By contrast, in this case, it will reduce around 18 percent in far future. In this case research, the river discharge will increased in autumn and will decreased in spring seasons. Likewise, results of estimation showed that the annual peak flow will shifted from month of March to the April.
Ali Ahmadabadi, Zahra Sedighifar,
Volume 18, Issue 51 (6-2018)
Abstract
Climate change is one of the most important challenges that has affected various parts of human life on Earth. In the present study, in order to investigate the climate change, three synoptic stations of Karaj, Mehrabad and Dashan Tepeh with the help of the statistical statistic downscaling model (SDSM) model were used to predict the statistical period of 2016-2045. Finally, the effects of climate change on the hydrologic conditions of the basin with the help of the model (SWAT) was simulated by the Soil and Water Assessment Tool. The amount of surface runoff and runoff at the study area is 10.59 mm in the studied observation period, but this rate was estimated to be 21.27 mm for the predicted period due to the increase of urbanization and changes in utilization. The results of the research, while highlighting the importance of the effects of climate change, are necessary for their application in applying proper management to adapt to climate change in the future policies of the basin management.
Mohammadreza Goodarzi, Atiyeh Fatehifar,
Volume 19, Issue 53 (6-2019)
Abstract
In the present time, with the increase of industrial activities and the neglected environmental issues, the effects of climate change have become more evident and poses this phenomenon as a global difficult. Increasing the probability of occurrence of extreme climatic events such as flood and increasing the frequency and intensity of the effects of climate change. The northwest of the country is one of the most vulnerable areas of the country due to its semi-arid and mountainous climates and high rainfall variability. Therefore, zoning due to climate change is essential. Therefore, in this study, in order to investigate the risk of flood in the Azarshahr basin, due to climate change, using the CanESM2 general circulation model under RCP8.5 scenarios negativity according to the assessment report fifth IPCC, rainfall and temperature variables were down scaling by Statistical down scaling model (SDSM). Then,with hydrological model SWAT the daily runoff, the basin map and the lines of the canals are achieved. The results of the evaluation of the SDSM model with a coefficient of determination and Nash-Sutcliff 0.95 on average represent the good performance of the model in the down scaling of large scale data. The results show an increase of 0.23 ° C and 4.53% rainfall and maximum discharge. The basin is zoned with the combination of the maximum mean discharge map, the coefficient and distance from the river with the AHP approach. Due to the zoning they are 41.55% of the area of the basin, at very low and low risk, 27.23% at average risk and 31.2% at high and very high risk. Also, with the final map, it became clear that the mid-basin had a high risk due to its prerequisite conditions and that it needed to carry out managerial actions.
Mrs Elaheh Asgari, Dr Mohammad Baaghideh, Dr Majid Hosseini, Dr Alireza Entezari, Dr Asghar Kamyar,
Volume 21, Issue 63 (12-2021)
Abstract
Understanding the main components of the watershed water basin and analyzing their hydrologic behavior are among the key components of any planning and management procedures in the field of water resources engineering. Today, the need to use modern technologies in hydrological modeling of watersheds has been discussed more than before. The purpose of this study is the simulation of hydrological components in various land use categories in the catchment area of the Dez river basin. Since the tool used in the research is the SWAT model and the SUFI-2 algorithm, the database used include a range of input data. In order to determine the level of sensitivity of the model to the input parameters, global sensitivity analysis was performed. Then, by adjusting the selected parameters and using the observation current, the model was calibrated and validated for the periods 2007 - 1994 and 2013 - 2008, respectively. The coefficients of NS, R2, P-factor and R-factor confirmed the model's ability to simulate river flow in the studied basin. The results of the model showed that the areas with forest use share the highest contribution to aquifer nutrition, and the barren lands have the highest surface runoff. Surface runoff has the leading role in creating the main stream of the river and after that the main flow has been effective in this area. The forest use change to Agricultural lands and pasture will change the hydrological parameters of the basin, and the result of these changes will lead to the increase in the surface runoff, the reduction of nutrition of groundwater resources and the reduction of river basin water. The SWAT model can be used as a precursor model in watershed management studies.
Mrs Somayeh Naderi, Prof. Bohloul Alijani, Prof. Zahra Hedjazizadeh, Dr. Hasan Heidari, Dr. Karim Abbaspour,
Volume 24, Issue 73 (6-2024)
Abstract
Evidence suggests that climate change will create uncertain regional agricultural production stability in the coming decades. This research investigated the impact of climate change on hydrology and sugar beet yield as one of the main crops in the Urmia lake basin using the Soil and Water Assessment Tool (SWAT). To address this, a baseline SWAT model was setup for 1986-2014. Afterward, the output was calibrated (1989-2004) and validated (2005-2014) in the SWAT-CUP software using the SUFI2 algorithm to simulate streamflow of 23 gauging stations and crop yield. The Nash-Sutcliffe efficiency was 0.43 and 0.53 for calibration and validation periods, sequentially. The Percent Bias was 45% and 16% for calibration and validation periods, respectively. As well as the agreement indices of 0.71 and the little Percent Bias (-6% to 10%) for crop production, verified the model's efficiency. The next step was downscaling and bias-correction of the precipitation and temperature data received from 3 climate models, namely GFDL, HadGEM2, and IPSL under RCP4.5 and RCP8.5 using CCT program. Then, the downscaled data were fed to SWAT, and Finally, hydrological fluxes and sugar beet yield were estimated for 2021-2050. Despite a dispersion of precipitation changes ranging from -12% to +35% in most scenarios, results highlight the pivotal role that the warmer temperature (+2.7°C) increases evaporation, resulting in sharpened pressure on water resources and runoff, especially, at the beginning of crop growth season. Finally, the negative impacts on crop productivity (-45%) is not unexpected. This means that sugar beet may suffer from climate change impacts, and the production of this plant will change over the next period in this region.
Keywords: Climate Change, Sugar Beet, Urmia Lake Basin, Sensitivity Analysis, SWAT.
