Hydrological study and analysis for proposed Al-Arkhama Dam, Iraq

Abstract

The hydrological study and analysis for the proposed Al-Arkhama Dam which is located 90 km south west of Kirkuk City is presented in this work. The main aim of this research is to estimate the probable maximum flood (PMF) to perform the main objective of constructing the proposed dam through designing the necessary hydraulic structures. For the analysis of the maximum annual rainfall, the asymptotic extreme distribution type I was adopted as theoretical model. The computed PMF discharge for return periods of 5, 10, 50, 100, and 1000 years for the proposed Al-Arkhama Dam catchment area were 48, 66, 112, 134 and 212 m3/s, respectively. The PMF hydrographs of the 25, 50, 100, and 1000 years return periods were computed. The results show that uncertainty of using the SCS-CN method for estimating PMF increases if the values of its parameters are not optimized. In addition, to determine the peak runoff in the study area, this method is better than the rational method, which is permissive in estimation of peak runoff. However, in the proposed location of the Al-Arkhama Dam, considerable amount of water can be harvested. Consequently, this quantity can contribute in solving the problem of water shortage within the region. Moreover, this dam could be very useful in mitigation of the drought and flood risks in the study area and Tigris River. However, assessment of the surface runoff and sediment yield spatiotemporal distribution and the method of mitigation of these yields should be investigated.