Impact of Improved Operation and Maintenance on Cohesive Sediment Transport in Gezira Scheme, Sudan IHE Delft PhD Thesis Series

Irrigated agriculture remains to be the main option to boost the economy in Sudan in general. It can rise the living standard of the majority of the population; particularly those who are attached to farming and livestock. With the expected increase in population in the next decades, water management of large irrigation systems will become a key issue to increase productivity and assure future food security.
Sediment transport in irrigation canals makes water management very complicated. This study focuses on water management in Gezira Scheme, Sudan. This scheme is irrigated from the Blue Nile River, which is characterized by a high sediment concentration. The aim of the study was to reduce the impact of fine sediment deposition in irrigation canals by improving the operation and maintenance procedures. A numerical model has been developed to simulate the cohesive sediment transport in irrigation canals. This model is a useful tool for the operators and decision makers to assess different options of operation in terms of sediment transport. This study found that sediment deposition in the canals can be minimized if the operation based on crop water requirement is adjusted at a certain period during the flood season.

Cohesive sediment transport

Sediment transport under non equilibrium conditions

Overview of cohesive sediment transport models

Data collection and scheme analysis

Water level measurement

Flow measurement and calibration of measuring structures

Numerical model development

Effect of sediment on the hydrodynamic behaviour of irrigation canals

Effect of different operation scenarios on the sedimentation

Sediment management

Ishraga S. Osman is a lecturer at the Civil Engineering Department, University of Khartoum, Sudan. She worked as researcher at the UNESCO Chair in Water Resources, Sudan, from 2003 till 2009. She is engaged in a number of projects and became a member of the River Morphology Cluster of the Nile Basin Capacity Building Network. She is involved in the "Nile Basin Reservoir Sedimentation Prediction and Mitigation project" in addition to several studies related to water management in irrigation canals, assessment of irrigation performance and sediment transport studies. She engaged in teaching, research, consultancy and supervision of BSc theses