SUSPENDED AND BED LOAD OF GREAT ZAB

Abstract

This study was conducted on the Great – Zab river at Eski Kalak monitoring station (3618 N , 4333- E , 280m A.S.1). The river of Great – Zab drains on area of 31258 Km2, this area is located between latitude 35.3 , 38.06 N and longitude 42.5 , 46.05 E. Suspended sediment concentration and bed load were determined for the period from August 2009 till April 2010 (9 months). Results showed that the amounts of monthly suspended sediments for study period (9 months) were 148 , 150 , 360 , 880 , 120 , 80 , 960 , 900 , 80 mg/L respectively. Bed load in this study was estimated as 10% of the suspended load, while grain size analysis of bed material was done by using the sieve analysis and hydrometer analysis then grain size distribution curve was observed. A Statistical model was assumed to fit the sediment concentration and the five dimensionless variable such as (Width B/ depth d), (d/D50), (Stream velocity (v) / settling rate (w)) , Renold number (vd/) and Froud number (v2/dg), and some of data transformation were made. Stepwise procedure used to select the best equation , and the selected equations that gave good fit are as follow:Log Cs = 0.29223 + 1.45474 Log – 2.24509 Log + 0.86603 Log + 0.60574 Log Log Cs = 2.16664 + 5.50975 – 2.17494 - 0.01037 + 0.31220 + 0.00125