Performance assessment of the Gash Delta Spate Irrigation System, Sudan
The Gash Delta Spate Irrigation System (GDSIS), located in eastern Sudan with a net command area of 100 000 ha (an area currently equipped with irrigation structures), was established in 1924. The land is irrigated every 3 years (3-year rotation) or every 2 years (2-year rotation) so that about...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-02-01
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| Series: | Proceedings of the International Association of Hydrological Sciences |
| Online Access: | https://www.proc-iahs.net/376/69/2018/piahs-376-69-2018.pdf |
| Summary: | The Gash Delta Spate Irrigation System (GDSIS), located in eastern
Sudan with a net command area of 100 000 ha (an area currently equipped with
irrigation structures), was established in 1924. The land is irrigated every
3 years (3-year rotation) or every 2 years (2-year rotation) so that
about 33 000 or 50 000 ha respectively can be cultivated annually. This
study deals with assessing the performance of the 3- and 2-year rotation
systems using the Monte Carlo simulation. Reliability, which is a measure of how
frequently the irrigation water supply satisfies the demand, and
vulnerability,
which is a measure of the magnitude of failure, were selected as the performance
criteria. Combinations of five levels of intake ratio and five levels of
irrigation efficiency for the irrigation water supply of each rotation system
were analysed. Historical annual flow data of the Gash River for 107 years were
fit to several frequency distributions. The Weibull distribution was the best
on the basis of the Akaike information criteria and was used for simulating the
ensembles of annual river flow. The reliabilities and vulnerabilities of both
rotation systems were evaluated at typical values of intake ratio and
irrigation efficiency. The results show that (i) the 3-year rotation is
more reliable in water supply than the 2-year rotation, (ii) the
vulnerability of the 3-year rotation is lower than that of the 2-year rotation
and (iii) therefore the 3-year rotation is preferable in the GDSIS. The
sensitivities of reliability and vulnerability to changes in intake ratio and
irrigation efficiency were also examined. |
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| ISSN: | 2199-8981 2199-899X |