آثار تغيير اقليم بر منابع آب سطحي و زيرزميني توسط مدل جامع هيدرولوژيك هيدروژئوسفر در دشت همدان-بهار

چكيده انگليسي :

Impacts of Climate Change on Surface and Groundwater Resources in Hamadan Bahar Basin Using HydroGeoSphere Hossein Talebmorad h talebmorad@gmail com Date of submission Feburuary 19 2012 Department of Water Engineering Isfahan University of Technology Isfahan 841156 8311 IranDegree M Sc Language Farsi st 1 J Abedi Koupai supervisor Koupai@cc iut ac ir 2nd S S Eslamian supervisor saeid@cc iut ac ir Abstract Estimating the impacts of climate change on groundwater represents one of the most difficult challenges faced by water resources specialists One difficulty is that simplifying the representation of the hydrological system often leads to discrepancies in projections This study provides an improved methodology for estimation of the impacts of climate change on surface and groundwater reserves where a physically based surface subsurface flow model is combined with advanced climate change scenarios for Hamadan Bahar basin 2459 km2 Iran Coupled surface subsurface flow is simulated with the HydroGeoSphere The simultaneous solution of surface and subsurface flow equations in HydroGeoSphere as well as the internal calculation of the actual evapotranspiration as a function of soil moisture at each node of the defined evaporative zone improved the representation of interdependent processes like recharge which is crucial in the context of climate change More simple models or externally coupled models do not provide the same level of realism Climate change simulations were obtained from HADCM3 general circulation model GCM scenarios assuming the SRES A2 A1B B1 emission scenarios These GCM scenarios were downscaled using LARS WG stochastic downscaling model Analyzing the observed weather data showed that distribution of observed daily precipitation is not normal and minimum and maximum daily temperature have autocorrelation Therefore nonparametric methods were used to compare the observed and simulated data by LARS WG Comparison of simulated and observed data and uncertainty analysis of downscaled data verified LARS WG ability in weather data generation In calibration step of HydroGeoSphere model in order to run the model in transient mode and get its responses to daily tensions the model was first run in steady state in order to apply its results as the initial conditions for transient mode using last 20 years average precipitation data and aquifer discharge The model was run in transient mode during 1992 2005 period and model parameters were calibrated In validation step the model was run during 2006 2010 period and the performance of the HGS model was verified The combined use of an integrated surface subsurface modeling approach a spatial representation of the evapotranspiration processes and sophisticated climate change scenarios improves the model realism and projections of climate change impacts on water resources According to climate change scenarios predictions except A2 emission scenario at 2071 2100 period which the precipitation is less than control period future is hotter and wetter than now Maximum increase in mean annual minimum and maximum daily temperature occurred in A2 emission scenario 4 75 and 4 63 C and minimum increase in mean annual minimum and maximum daily temperature occurred in B1 emission scenario 2 81 and 2 69 C Maximum increase in mean annual daily precipitation occurred in B1 emission scenario in 2011 2040 period 19 and maximum decrease in mean annual daily precipitation occurred in A2 emission scenario in 2071 2100 period 8 Integrated flow simulations showed that significant decreases are expected in the groundwater levels by 2100 Maximum and minimum decrease in groundwater level happened in A2 9 m and B1 7 m emission scenarios respectively Total water mass balance didn t change significantly in comparison with control period Comparison between groundwater level decrease under different emission scenarios and aquifer discharges showed that severe groundwater withdrawal is the major problem in the study re

طالب مراد، حسين

آثار تغيير اقليم بر منابع آب سطحي و زيرزميني توسط مدل جامع هيدرولوژيك هيدروژئوسفر در دشت همدان-بهار

كوچك مقياس كردن , GCM , LARS-WG