Hydraulic characteristics of the lower part of Diyala River

Abstract

Abstract A one-dimensional hydraulic model was conducted to simulate the flow in Diyala River. The research aims to study the flow capacity along Diyala River and especially concerning on reach of the river within Baqubah City during flood seasons by using HEC-RAS, 5.07 software. Moreover, specifying the hydraulic problems and then the necessary treatments to overcome them were suggested. A 190 km length of the reach of Diyala River was included in this study, starts from Diyala submerged weir to the confluence of Diyala-Tigris River south of Baghdad City. Good agreement resulted between the measured and the simulation results with a determination coefficient (R2) value of 0.84 with Manning Coefficients in the steady-state flow of 0.028 and 0.045 for the main channel and for the over-banks of Diyala River, respectively. Moreover, the model results and the field surveying of the river showed that the flood capacity of the Diyala River within Baqubah City is cannot be exceeding 750 m3/sec. Also, the flood-prone areas were identified, that they were located between Kharnabat to Um Al-Atahm, which requires training for the cross-sections and rising the embankments to increase the discharge capacity of the river for more than of 1000 m3/sec.