B. Ashraf; A. Alizadeh; M. Mousavi Baygi; M. Bannayan Awal
Abstract
Scince climatic models are the basic tools to study climate change and because of the multiplicity of these models, selecting the most appropriate model for the studying location is very considerable. In this research the temperature and precipitation simulated data by BCM2, CGCM3, CNRMCM3, MRICGCM2.3 ...
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Scince climatic models are the basic tools to study climate change and because of the multiplicity of these models, selecting the most appropriate model for the studying location is very considerable. In this research the temperature and precipitation simulated data by BCM2, CGCM3, CNRMCM3, MRICGCM2.3 and MIROC3 models are downscaled with proportional method according A1B, A2 and B1 emission scenarios for Torbat-heydariye, Sabzevar and Mashhad initially. Then using coefficient of determination (R2), index of agreement (D) and mean-square deviations (MSD), models were verified individually and as ensemble performance. The results showed that, based on individual performance and three emission scenarios, MRICGCM2.3 model in Torbat-heydariye and Mashhad and MIROC3.2 model in Sabzevar had the best performance in simulation of temperature and MIROC3.2, MRICGCM2.3 and CNRMCM3 models have provided the most accurate predictions for precipitation in Torbat-heydariye, Sabzevar and Mashahad respectively. Also simulated temperature by all models in Torbat-heydariye and Sabzevar base on B1 scenario and, in Mashhad based on A2 scenario had the lowest uncertainty. The most accuracy in modeling of precipitation was resulted based on A2 scenario in Torbat-heydariye and, B1 scenario in Sabzevar and Mashhad. Investigation of calculated statistics driven from ensemble performance of 5 selected models caused notable reduction of simulation error and thus increase the accuracy of predictions based on all emission scenarios generally. In this case, the best fitting of simulated and observed temperature data were achieved based on B1 scenario in Torbat-heydariye and Sabzevar and, A2 scenario in Mashhad. And the best fitting simulated and observed precipitation data were obtained based on A2 scenario in Torbat-heydariye and, B1 scenario in Sabzevar and Mashhad. According to the results of this research, before any climate change research it is necessary to select the optimum GCM model for the studying region to simulate climatic parameters.
hadi sanikhani; yaghoub dinpazhoh; sarvin zamanzad ghavidel
Abstract
Changes in temperature and precipitation patterns have serious impacts on the quantity and quality of water resources, especially in arid regions such Iran. In recent years, frequent droughts have threatened the water resources in Iran. Because of the increasing demand for water, studying the impacts ...
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Changes in temperature and precipitation patterns have serious impacts on the quantity and quality of water resources, especially in arid regions such Iran. In recent years, frequent droughts have threatened the water resources in Iran. Because of the increasing demand for water, studying the impacts of climate change on water resources is necessary. In this study, the impacts of climate changes on run-off in Ajichay watershed, located in East Azerbaijn were considered. To predict the climate change based on the General Circulation Models (GCM), the LARS-WG tool for downscaling was used. By using LARS-WG, climate change in Ajichay watershed by applying HADCM3 model and three emission scenarios, A1B, A2 and B1 in 2055 horizon was investigated. The results show a rise in temperature and reduction in precipitation. In the other part of the research, for simulationofthe impacts of climate change on watershed run-off, Gene Expression Programming (GEP) was used. The results indicated that significant reduction in run-off. With regarding the results of this research, for adaptation with climate change, it is necessary to consider suitable management action in this watershed.
mostafa rezaee; saeed morid
Abstract
Lake Urmia is faced with problematic drawdown trend in the recent years that climate change can exacerbate this phenomena. This research work applies HadCM3 climate change data (scenarios A2 and B2) for the period of 2010-39 to evaluate changes in temperature and rainfall of the basin. To downscale these ...
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Lake Urmia is faced with problematic drawdown trend in the recent years that climate change can exacerbate this phenomena. This research work applies HadCM3 climate change data (scenarios A2 and B2) for the period of 2010-39 to evaluate changes in temperature and rainfall of the basin. To downscale these data a new approach is used, which is a combination of SDSM model and TOPSIS approach. Furthermore, the climate change data was introduces to the Soil and Water Assessment Tools model (SWAT) that was calibrated using local data and information to evaluate future changes in the basin’s runoff. Of course at this stage, only the Simineh Rud subbasin as one of the basin’s main subbasin was investigated. The results showed that climate change will reduce monthly rainfalls up to 40% and increase the temperatures up to 2 °C. Also, the basin’s runoffs will face with reduction of about 25%. Consequently, the inflows to lake may decrease about 30%. In general, the results of this research work emphasize on more attentions to the problems of the lake that will be booster under climate change condition
M. Rezaei; M. Nohtani; A. Moghaddamnia; A. Abkar; M. Rezaei
Abstract
One of the most important problems in the management and planning of water resources is to forecast long-term precipitation in arid region and hyper arid regions. In this study, statistical downscaling model (SDSM) is used for study of climate change effects on precipitation. The data used as input to ...
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One of the most important problems in the management and planning of water resources is to forecast long-term precipitation in arid region and hyper arid regions. In this study, statistical downscaling model (SDSM) is used for study of climate change effects on precipitation. The data used as input to the Model are daily precipitation of Kerman and Bam synoptic stations, NCEP (National Centers for Environmental Prediction) data and the A2 and B2 emission scenarios HadCM3 for the reference period (1971-2001). Using HadCM3 A2, B2 data the precipitation for three period (2010-2039), (2040-2069) and (2070-2099) are predicted and compared with the reference period. We used the first 15 years data (1971-1985) for the calibration and the second 15 years data (1986-2001) for model validation. Research results showed that the precipitation will change and Change directions are positive in some months and negative in other months. After the examination function Indexes results from SDSM model shown that this model has better accuracy and a high ability to predict precipitation in arid region than hyper arid region.
M. Azari; Hamid Reza Moradi; B. Saghafian; M. Faramarzi
Abstract
Climate change is one of the most significant challenges that all living matters on the Earth needs to face. A warmer climate will accelerate the hydrologic cycle, altering rainfall, magnitude and timing of runoff.Iran might become one of the most vulnerable areas in the world regarding climate change. ...
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Climate change is one of the most significant challenges that all living matters on the Earth needs to face. A warmer climate will accelerate the hydrologic cycle, altering rainfall, magnitude and timing of runoff.Iran might become one of the most vulnerable areas in the world regarding climate change. To study the effects of climatic variations, the Soil and Water Assessment Tool (SWAT) model was implemented to simulate the hydrologic regime on Gorganroud basin. The SUFI-2 algorithm in the SWAT-CUP program was used for parameter optimization using the monthly river discharge. The climatechange scenarios were constructed using outcomes of three General Circulation Models (CGCM2, HadCM3 and SCIRO)for low and high levels of greenhouse gas emission scenarios (A1F1 and B1). The calibration andvalidation results of the SWAT model agreedwell with the observed data. The study result showed that Compared with the present climate, the climate models predicted a −3.2% to -6.5% changes in annual precipitation, 3 to 5.7°C rises in maximum temperature, and 2.8 to 5.2°C rises in minimum temperature. SWAT predicted a −0.4% to -7.7% changefor runoff, −5.2% to -13% change for soil water content, 5.3% to 10.2% change for water yield, and -1.6% to -3.6% decrease for evapotranspiration during 2010–2039 under all climate scenarios.These results highlight the strong impact of climate change in regional water resources and reflect the importance of incorporating these analysis into adaptive management in the future watershed management strategies.
J. Fallahi; P. Rezvani Moghaddam; M. Nassiri Mahallati; Mohammad Ali Behdani
Abstract
Climate change by increasing concentrations of greenhouse gases, particularly carbon dioxide, has led to increase attention to the carbon sequestration through the restoration and protection of vegetation cover. In this regards, ecosystems of arid regions have a special importance. In this study the ...
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Climate change by increasing concentrations of greenhouse gases, particularly carbon dioxide, has led to increase attention to the carbon sequestration through the restoration and protection of vegetation cover. In this regards, ecosystems of arid regions have a special importance. In this study the effects of reconstruction and conservation, on soil carbon sequestration of the region of the International Carbon Sequestration Project in Hussein Abad, South Khorasan province of Iran was investigated by a simulation approach using RothC model. In addition, the effects of climate change (increasing temperature and decreasing rainfall) on soil carbon sequestration potential was studied. In the studied area, replanting was done in 2004 and then soil samples were taken every two months during 2010-2011. After collecting the required input data for RothC model (climate, soil and management input data), the model was evaluated and validated for the study area. Moreover, soil carbon sequestration was studied under climate change condition. The simulation results revealed that the RothC model is applicable in rangelands of dry and warm regions, because it estimated the soil carbon changes over the time with proper accuracy. The amounts of model performance index, R2 and RMSE were 0.98, 98% and 0.01, respectively. Simulation study indicated that soil carbon storage will increase from 2011 to 2050 and will be affected by climate change and protection programs. Based on model estimation the amounts of soil carbon in preotected areas will be higher than non-protected areas. Moreover, in non-climate change scenario the amounts of soil carbon will be higher than climate change scenario in 2050.
H. Seyyed Kaboli; A.M. AkhodAli; A.R. Masah Bavani; F. Radmanesh
Abstract
General Circulation Models (GCMs) have been identifiedas asuitable tool for studying climate change. Butthese models simulate climatic parametersinthe large-scale which has poor performance in the simulation of processes such asrain fall-run off. There fore, several of down scaling methods were developed. ...
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General Circulation Models (GCMs) have been identifiedas asuitable tool for studying climate change. Butthese models simulate climatic parametersinthe large-scale which has poor performance in the simulation of processes such asrain fall-run off. There fore, several of down scaling methods were developed. This researchis presented down scaling model based onk-nearest neighbor (K-NN) non-parametric method. The modelis used to simulate daily precipitation data in Ahvaz station for the next period (2015-2044) under climate change scenarios based on out puts of three General Circulation Models, including HADCM3, NCARPC Mand CSIROMK3.5. The results indicate that them odelhasa high capacity for down scaling data. It is predicted that the frequency of storm is increased with high intensity on future period in Ahvaz station while dry spells will be prolonged.
