Quantification of Sedimentation Processes in the Gezira Irrigation Scheme-Sudan
Gezira scheme of Sudan is considered as the country s largest irrigation scheme. It had been developed on land between the Blue Nile and White Nile rivers south of their confluence at Khartoum. This area is generally flat with a gentle slope to the north and west, permitting natural gravity irrigation, and its soils are fertile cracking clays well suited to irrigation. The scheme is irrigated from the Blue Nile through water diversion from Sennar dam. The scheme comprises a network of canals of different types and sizes. The types of canals are categorized as main, major, minor and field irrigation canals. The discharges of those canals vary from more than 100 cubic meters per second to less than 1.0 cubic meters per second. The water is controlled by means of regulators grouped at various kilometrage and normally each group of regulators carries the name of that kilometrage, for example km 57 group of regulators. The zero kilometer is at the canal intake. The scheme area equipped for irrigation is more than 800 thousand hectares with a 5-course crop rotation. The water of the Blue Nile is sediment laden water particularly during the flood season during the period June to October. The sediment concentration of the Blue Nile varies from a few hundred ppm to more than 30,000 ppm. The total sediment load of the river is estimated at about 140 million tons annually. The Gezira scheme is heavily sedimented and this imposes overburden on the annual operation cost of the scheme. A sediment monitoring program at the key group of regulators was launched since the early 1990s of the last century and continues up to now. The monitoring program is aiming at quantifying the amount of sediment that enters the Gezira scheme, the rate at which that takes place, and the way in which it is distributed. This paper presents the result of this study and comparisons with results obtained at various years during the monitoring program were made.
sedimentation processes sediment monitoring program sediment characteristics sediment concentration sediment quantities
Siddig Eissa Ahmed
Water Resources, HRS, MOIWR, Sudan
国际会议
郑州
英文
495-502
2009-10-20（万方平台首次上网日期，不代表论文的发表时间）