مقايسه روش هاي تعيين دبي در جريان هاي طبيعي با استفاده از اندازه گيري صحرايي سرعت جريان

The basement of large part of hydrology in the field of morphology and behavior of rivers is on the results of hydrometry. Many of equations that are used in design of water systems obtained from empirical data and measurement in the field. Correction or completing these equations depends on these data sets. One of the hydrometry data sets that are used in hydrologic analysis is discharge. One of the usual methods for estimating discharge in rivers and natural channels is the measurement of velocity in

The basement of large part of hydrology in the field of morphology and behavior of rivers is on the results of hydrometry. Many of equations that are used in design of water systems obtained from empirical data and measurement in the field. Correction or completing these equations depends on these data sets. One of the hydrometry data sets that are used in hydrologic analysis is discharge. One of the usual methods for estimating discharge in rivers and natural channels is the measurement of velocity in several points in one section and calculating average velocity. The methods that are used by engineers to determine average velocity are: 1 point method, 2 points method, 3 points method and 5 points method. In this article these methods are evaluated and compared by using of measured velocity profile data in several sections of three reaches in Kaj River in Chaharmahal and Bakhtiari province. The results show that there is no significant difference between all of these methods and they have same accuracy. Thus, simplicity of one method is a good reason for choosing it.