تعيين مناسب ترين روش تجربي برآورد رواناب سالانه در حوزه آبخيز فاقد آمار در مناطق نيمه خشك (مطالعه موردي رودخانه رودبال شهرستان داراب

Determination of a suitable practical method to calculate run off in watershed basins havenʹt a hydrometric station in semi arid regions. "study on Roodbal river in Darab"

One of the most important factors in designation and determination of the kind of obstruction of soil conservation and watershed management is the identification of height and volume of yearly run off in each height level and all area for a watershed basin. Also to proper use of water surface the run off volume must be preciesly eslimated. There are many practical methods for determination of the yearly run off volume in watershed basins. The objective of this study was to identify a suitable practical method. For this purpose the information of 17 years of the rainfall and the temprature of watershed basin in Roodball river at Darab region were extracted and the volume and the height of rainfall for each height level was calculated using regression relationships. Then the volume of yearly run off for each leveln and all basin calculated, based on temprature and rainfall using Tourk, Kotain, and Longbin practical methods. The results evaluated by t-test. The results of Kotain and Longbin methods showed significant difference at 0.05 level. But there wasnʹt any significant differences between Tourk and volume of run off that had been recorded in the out let of basin.