Due to its geographical location an‎d specific climatic conditions, Isfahan region has always faced challenges of water shortage an‎d drought, an‎d a precise understan‎ding of evapotranspiration dynamics is of great importance. The aim of this study is to compare ETp (two methods of Thornthwaite an‎d Hargreaves) between dry an‎d wet periods using moving averages of precipitation of 3, 5, 7 an‎d 9 years for 15 study stations in Isfahan, an‎d also to compare rainfall between hyperevapotranspiration an‎d hypoevapotranspiration periods using moving averages based on ETp (two methods of Thornthwaite an‎d Hargreaves) of 3, 5, 7 an‎d 9 years in 15 study stations in Isfahan. This study compares the performance of two linear regression models, including the potential evapotranspiration method of Thornthwaite an‎d the potential evapotranspiration method of Hargreaves, an‎d also using four periods of 3 years, 5 years, 7 years an‎d 9 years. The data used for this analysis are from 15 synoptic meteorological stations located in the Isfahan region an‎d the 21-year statistical period from 2003 to 2023. The moving average of precipitation was plotted for each station an‎d for periods of 3, 5, 7 an‎d 9 years, an‎d the dry an‎d wet periods of each station were determined. The results of the regression between the total potential evapotranspiration of the dry an‎d wet periods of the studied stations did not indicate the desired results, an‎d the desired results were not obtained with the Dumartin climate classification. In the next step, the results of the regression between the average potential evapotranspiration of the wet an‎d dry periods of the studied stations were performed, which indicated the superiority of the Thornthwaite ETp method over Hargreaves an‎d also the better results of the short-term periods. The moving average based on ETp (two methods of Thornthwaite an‎d Hargreaves) was plotted for each station an‎d for periods of 3, 5, 7 an‎d 9 years an‎d the periods of over- an‎d under-evapotranspiration of each station were determined. The results of the regression between the average potential evapotranspiration of the over- an‎d under-evapotranspiration periods of the studied stations were performed, which indicated the superiority of the Hargreaves ETp method over Thornthwaite an‎d also better results for short-term periods. Also, the climate maps of the UNIP aridity index an‎d the UNIP aridity index were plotted for both the UNIP an‎d Hargreaves potential evapotranspiration methods for the 15 studied stations an‎d most of the stations had a dry climate.

جهانگير عابدي كوپائي

سعيد اسلاميان , محمد مهدي متين زاده

سعيد سلطاني كوپائي , منوچهر حيدرپوراسفرجاني