UNESCO-IHE INSTITUTE FOR WATER EDUCATION Hydraulic Design and Performance Assessment of Malwan Irrigation Scheme in North Iraq (Kurdistan Region) Ruaa Khalid Hamdan MSc Thesis (WSE-LWD-08.10) April 2008 Hydraulic Design and Performance Assessment of Malwan Irrigation Scheme in North Iraq (Kurdistan Region) Master of Science Thesis By Ruaa Khalid Hamdan Supervisors Prof. E. Schultz, PhD, MSc (UNESCO-IHE) F.X. Suryadi, PhD, MSc (UNESCO-IHE) Examination committee Prof. E. Schultz, PhD, MSc (UNESCO-IHE), Chairman Ir. P.H.J. Hollanders (Principal Water-board of Delfland) F.X. Suryadi, PhD, MSc (UNESCO-IHE) This research is done for the partial fulfillment of requirements for the Master of Science degree at the UNESCO-IHE Institute for Water Education, Delft, the Netherlands Delft April 2008 The findings, interpretations and conclusions expressed in this study do neither necessarily reflect the views of the UNESCO-IHE Institute for Water Education, nor of the individual members of the MSc committee, nor of their respective employers. This thesis is dedicated to my parents for their love and care. Acknowledgements Acknowledgements All Praise is to Allah, the Lord of the Worlds. To my Parents, Aunts, Sister and Brothers who support me and give me the power and the patience, to complete this study, I present this work to them. Thanks and gratitude to Professor Bart Schultz for his valuable guidance and advices, thanks to Dr. Suryadi for his support and guidance. Many thanks to the Director of Irrigation in Sulymania and the other staff members for providing me with information. Special thanks to the entire support staff of UNESCO-IHE, my friends and my classmates for their support. Ruaa K. Hamdan i Hydraulic design and performance assessment of Malwan Irrigation Scheme in North Iraq (Kurdistan Region) Ruaa K. Hamdan ii Summary Summary Design of irrigation systems is a complex process; it involves a large number of criteria. At any stage during the design phase feedback is necessary in order to optimize the final product. The optimization in the design phase requires an investment of time to get the most appropriate solution. In conventional design, this process of optimization was not really carried out because of lack of time. Nowadays with the enormous advance in computer techniques and with the support of powerful tools such as the DUFLOW and other computer programs, designers are able to find the most suitable solution by analyzing various alternatives in a much shorter period. At present, computer programs are available for the design of irrigation systems that allow the designer to evaluate and to check the hydraulic performance of each part of the irrigation system independently. The present research was focused on the evaluation of the design of Malwan Irrigation Scheme in North Iraq (Kurdistan region). The specific objectives of the study were: • to assess the cropping potential of Malwan Irrigation Scheme and recommend possibilities for improvement of the scheme; • to assess the hydraulic sustainability of Malwan Irrigation Scheme, under the actual operation, maintenance and management condition; • to propose alternative solutions and determine to what extent the operational objectives of the irrigation agency can be fulfilled with the actual infrastructure; • to propose alternatives for improvement and analyze them by using DUFLOW modelling (the DUFLOW program is applied to investigate the impact of unsteady flow on the hydraulic performance of the irrigation canals, and to examine possible design and/or operational measures to improve the performance); • to recommend suitable design measures. The research focuses on three topics and under Topic 1 on these scenarios as presented in the Tables below: Topic Scenario 1- Water balance and 1 2 3 crop water requirements Without deficit Under deficit Changed cropping pattern Topic Description 2- Canal capacity By using the hydrodynamic program DUFLOW 3- Sedimentation in the canal system By using the SETRIC program Ruaa K. Hamdan iii Hydraulic design and performance assessment of Malwan Irrigation Scheme in North Iraq (Kurdistan Region) In Topic 1 the crop water requirement has been determined by using the program CROPWAT under different conditions. In both scenarios one and two of topic one five type of crops were selected (Cotton, Sunflower, Wheat, Barley and Small vegetables) according to the market of these crops in the area. The scenarios 1 and 2 are respectively without deficit and under deficit conditions. While in scenario three a new suggestion with respect to the cropping pattern and the irrigation scheduling has been made. Instead of planting five crops it will be eight different crops Potato, Tobacco and Beans will be added to the previous scenarios. These new crops will be planted after the harvesting of wheat and barley in the same tertiary unit, the peak discharge in this case will be a bit higher than the previous values, but with a higher income to the farmers from an economic point of view. Therefore scenario three of topic one is preferable for getting more chances to develop the cropping pattern as well as the economical benefits of the farmers. The second topic concerns the hydraulic design from different points of view, including options that permit to introduce hydraulic energy and sediment transport concepts, both with one common goal, namely to obtain a design, which avoids sedimentation and erosion in the irrigation canal network. Another feature of Topic 2 includes the possibility to improve the preliminary design results (based on steady state computations) based on DUFLOW (unsteady flow computer program) and SETRIC (sediment transport program) for further analysis of the operation and maintenance. In topic two, the cross sectional dimensions which were obtained from the preliminary design are improved with the DUFLOW program, to get the final dimensions (bed width, water depth) for the main and secondary canals in Malwan Irrigation Scheme. Further more in topic three the morphological performance of Malwan Irrigation Scheme has been checked with the SETRIC program. The link between the hydraulic design and the different programs for hydraulic and sediment transport modelling is a powerful element of analysis, because it combines two different approaches to solve the same problem: the steady and unsteady flow types in irrigation canals. In the simulation with SETRIC, the hydraulic design with “sediment control” option, showed to be appropriate. The incoming sediment load was transported through the whole canal system achieving the objective of the design. The result of the simulations showed that the hydraulic design with sediment criteria has the expected behaviour. The SETRIC program is recommended for testing the behaviour of sediments in irrigation canal conditions, it can also be used to test different operation and maintenance conditions and to determine a sediment efficient operation and maintenance practice in an irrigation canal. Similarly various design alternatives can be analyzed to determine a sediment efficient design of irrigation canals and thus helps as a design tool. Further study is necessary to validate the boundary conditions of erosion and deposition calculated in the model. An unsteady flow model would have to be applied to the system in order to support the decision- making process for improving operation and maintenance of the irrigation system. A short course for a number of engineers of the Malwan Irrigation Branch would have to be carried out in order to enable them to understand the software and to develop operation rules for all schemes. The DULOW program needs to be modified for irrigation networks and more types of control structures need to be added to the program in order to make the schematization simpler. Ruaa K. Hamdan iv Summary Executing the alternative scenarios during the irrigation season needs discussions with the farmers’ groups about the implications of the various operational options for changing the operational rules of the system in order to achieve the performance improvement goals. Ruaa K. Hamdan v Hydraulic design and performance assessment of Malwan Irrigation Scheme in North Iraq (Kurdistan Region) Ruaa K. Hamdan vi Table of contents Table of contents ACKNOWLEDGEMENTS....................................................................................................... I SUMMARY............................................................................................................................ III TABLE OF CONTENTS...............................................................................................VII List of symbols................................................................................................................... xi List of abbreviations ........................................................................................................ xiii List of tables.......................................................................................................................xv List of figures.................................................................................................................. xvii 1 INTRODUCTION.................................................................................................................1 1.1 General...........................................................................................................................1 1.2 Background information of the country.........................................................................4