One Dimensional Unsteady Flow Analysis :A Case Study of Tigris River

Abstract

One of the most important characteristics of the Iraqi rivers is the annual fluctuation, between a
wet year and another medium and dry years, and for this reason, the use of forecasting techniques became
necessary in planning, designing and managing water resources systems. In this investigation, the HECRAS
program was utilized to analyze unsteady one-dimensional flow in open channels ( Along the Tigris
River) the use of a hydraulic model can be developed in the analysis and monitoring of flow, which will
provide a means to understand and represent hydraulic properties and calculate the expected flows in a
river, as the flow in natural rivers is a basic parameter in water engineering such as building dams,
collecting water and intake rivers. The river length covered by the current investigation is 284.5 km, and
from the rear starts the Dam of Mosul to Baiji Station. The results obtained from the application of the
mathematical model HEC-RAS showed the model's ability to efficiently represent the runoff field and to
identify the characteristics of the river at different sites and under various flow conditions, during the
comparison between the calculated and observed hydrography, the mean error rate of is (0 .1442)