شبيه سازي جريان رودخانه پلاسجان تحت تأثير تغييرات اقليمي با استفاده از مدل WetSpa

چكيده انگليسي :

Simulation of Plasjan streamflow influenced by climate change using WetSpa model Saeid Toghyani saeid toghyani@ag iut ac ir December 18 2019 Department of Water Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language Farsi1st Supervisor Saeid Eslamian saeid@cc iut ac irAbstractIn recent decades water scarcity has become a global problem due to global population growth andincreasing per capita water consumption Increasing greenhouse gases in recent decades and risingtemperatures have caused widespread climate change in most parts of the globe Therefore awareness ofthe climate and water resources in each region is an important step in planning and managing waterresources and preventing potential hazards such as future floods and droughts From this perspective hydrological modeling in watersheds is important This study aimed to investigate and evaluate the flow ofthe Plasjan River using the WetSpa hydrological model in future periods affected by climate change inthe Eskandari Watershed which is one of the sub basins of the Zayandehrood River In this study thesynoptic Daran and Fereydoon Shahr stations were used to collect meteorological data in the Eskandaribasin and daily data of the Eskandari hydrometric station located at the outlet of the basin were used tostudy the flow of the Plasjan River In order to conduct the present study the ability of WetSpa model tosimulate river flow was firstly evaluated and the watershed maps were extracted using WetSpa model Then the ability of the LARS WG model to evaluate the exponential scaling of GCM general circulationmodel s data was evaluated Then using the LARS WG model climatic data were generated in the nearfuture 2021 2040 and the distant future 2041 2060 under different scenarios RCP 2 6 RCP4 5 RCP8 5 The WetSpa model calibration and validation process was then performed Future climatic datagenerated in the previous step along with digital elevation maps soil texture and land use were input tothe WetSpa model And river runoff was calculated in the near future The results of the calibration andvalidation of the WetSpa model showed that the model has an acceptable ability to simulate river flow According to the studies if the Nash Sutcliffe coefficient is obtained between 0 50 and 0 65 it indicatesgood and acceptable model capability in simulating basin hydrological processes In this study the NashSutcliffe coefficient was 0 55 in the calibration stage and 0 54 in the validation stage Which showed thatthe model has a relatively good ability to simulate flow in the basin To evaluate the LARS WG model maximum and minimum precipitation and temperature statistics during the baseline period 1992 to 2005were used The results of the study of the effect of climate change on the temperature component of theregion showed that the temperature of the study area is about 1 5 to 3 C by 2040 near future and 2 5 to4 3 C by 2060 far future will increase The results show that temperatures will rise throughout the yearexcept January with the highest increase in July Also the effects of climate change on precipitationcomponent showed that precipitation increased in March October and November and decreased in othermonths The percentage of increase in precipitation will be between 7 and 37 percent The highest drop inprecipitation will be in May and around 27 under the RCP8 5 scenario in the near future The results alsoshow that basin surface runoff will decrease in all months to 2060 compared to baseline under all climatechange patterns The largest reduction in runoff over the base period will occur in April Runoff will alsodecrease by 2060 at the basin outlet in the most optimistic state by 15 and in the most optimistic state by about 65 over the baseline period Keywords Climate Change Surface Runoff Plasjan River RCP Scenarios WetSpa Hydrological Model

طغياني خوراسگاني، سعيد

شبيه سازي جريان رودخانه پلاسجان تحت تأثير تغييرات اقليمي با استفاده از مدل WetSpa

تغيير اقليم , رواناب سطحي , رودخانه پلاسجان , سناريوهاي RCP , مدل هيدرولوژيك WetSpa