The establishment of a” Time occurrence Max. water level stairs “chart through modeling break Hamrin Dam

Abstract

In this study, it was established of a “Time occurrence Max. water level stairs “chart for Dalia river through modeling dam break for Hamrin dam by using HEC-GeoRAS within GIS . Routing the water wave through the river, simulation and performed unsteady flow this model was done by using HEC-RAS. “Time occurrence Max. water level stairs “chart it’s useful for management risk and Decision-making for the evacuation of areas prone to flood risk and save lives , This is first objectives from this study.The second objective of the study was determined the floodplain and inundation area along the Diyala river up to Baghdad and determined the percentage of inundation within urban area near Dalia river, to make a decision and risk management in the event of breaking of the dam, also the Max. discharge when happened breaching in dam was 12.90 times the expected discharge when recurrence interval 100 year .