نوع مقاله : یادداشت فنی
نویسندگان
1 دانشکده مهندسی عمران - دانشگاه تحصیلات تکمیلی صنعتی کرمان
2 بخش مهندسی عمران - دانشگاه شهید باهنر کرمان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The spatial resolution of Global Climate Models (GCMs) is too coarse to resolve regional scale effect and to be used directly in local impact studies. Statistical downscaling techniques offer an alternative to improve regional or local estimates of variables from GCM outputs. In this study, an Adaptive Neuro-Fuzzy Inference System (ANFIS) using fuzzy c-means (FCM) clustering is presented and assessed to reconstruct the observed climate in Iran. Outputs from the third generation Canadian Coupled Global Climate Model(CGCM3) are used to test this approach over the current period (i.e. 1961e1990), and compare results with observed temperature and precipitation from two meteorological stations located in Tehran and Tabriz. Both ASD and ANFIS models, as these two models are evaluated and inter-compared, are calibrated using NCEP (National Center for Environmental Prediction) reanalysis data before the use of CGCM3 predictors. The omparison is performed over the period of ASD and ANFIS calibration (1961-1975) and over validation period (1976-1990), using NCEP predictors. The criteria for results comparison are computing the amount of model explained variance (R2) and Root Mean Squared Error (RMSE) for the estimated statistics and climatic indices. For stability and robustness of the downscaling results for each application of ASD and ANFIS models, 100 simulations were performed to produce 100 synthetic series of daily precipitation and maximum temperature. Daily precipitation and maximum temperature are generated for the periods of 2011-2040, 2041-2070 and 2071-2100 and compared to 1961-1990 period. Average maximum temperature for Tehran is 22.48, 23.52, 25.05, 26$.27^{0}C$ and average precipitation is 0.63, 1, 1.1 and 1.17 millimeter per day for the periods of 1961-1990, 2011-2040, 2041-2070 and 2071-2100 respectively. For the other station, Tabriz, average maximum temperature is $17, 18.31, 19.81, 21.30^{0}C$ and average precipitation is 0.84, .60, 0.47 and 0.33 millimeter per day for thirty years periods respectively. Results comparison indicates the increase of temperature for both stations precipitation behavior is totally different in Tabriz and Tehran stations.
کلیدواژهها [English]
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