TY - JOUR T1 - Modeling and analysis of Trend in the hydrological regime of rivers (Case Study: Gorganrood River, Tamar hydrometric stations) TT - مدلسازی و تحلیل تغییرات رژیم هیدرولوژیکی رودخانه ها (مطالعه موردی: رودخانه گرگانرود، ایستگاه هیدرومتری تمر) JF - ijwmse JO - ijwmse VL - 11 IS - 37 UR - http://jwmsei.ir/article-1-512-en.html Y1 - 2017 SP - 35 EP - 45 KW - Floods KW - hydrograph KW - rainfall KW - discharge KW - Tamar hydrometric station. N2 - In this researcher for study trend hydrologic regime gorganarood river in Tamar hydrometric station, using of information 44 years Tamar hydrometric station in years 1348 until 1391, analyzed and modeling by GIS, ILWIS 2.1 and SMADA software. Then, physical characteristics in watershed, climate, temperature, rainfall, discharge process, floods and hydrographic took analyze. Results showed that the climate is changing into warm and dry, the effects can be cited reduced rainfall and increasing temperatures, increased rainfall intensity and increased peak discharges areas. On the other hand, check average discharges and annual discharges rates increase relatively weak trend this parameter is mentioned in the watershed that with the global climatic changes in the northern 30◦- latitude. Specified with examining flood Tamar watershed most floods related in the months of November, March, April and May frequency was respectively in the amount of 14, 12,12 and 12 during the period 10 years. In the end, it was found watershed unit hydrograph with analyzing several important floods recorded in Tamar station and the assessment Basin focus time and distribution pattern of rainfall respectively was the floods hydrograph with return period 2 until 2000 years. M3 ER -