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| Titel |
Alternated pumping reduces the impact of freshwater diversion in the Pungue estuary |
| VerfasserIn |
M. Hegnauer, H. H. G. Savenije |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062066
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| Zusammenfassung |
| The Pungue river is a strongly seasonal river that is shared by Zimbabwe and Mozambique.
In Mozambique, its water resources are mainly used for water supply to the city of Beira
and for irrigation of the sugar estate near Mafambisse. The latter is the main user
with a pumping capacity of 7.2 m3/s. During dry periods, salt water intrudes until
and even past the water intake, resulting in the shutting down of pumps near high
tide.
Previous research identified unexpectedly low salinities near the water intake during
extremely low river discharge, while model simulations suggested substantially
higher salinities. This contribution presents the theory that explains the observed
anomalies, making use of the observations made by previous researchers aswell as newly
retrieved data in 2009. In this theory the dynamic effects, introduced by on and
off switching of the pumps at Mafambisse, is the main reason for the steady state
model not to fit the observations. To test this theory, a virtual experiment with a
dynamic salt intrusion model has been done of which the results are presented in this
contribution.
An interesting conclusion from the experiments is that by alternated pumping, the salinity in
the estuary remains close to the steady state salinity of the undisturbed discharge. This means
that alternated pumping is a highly efficient way of water consumption with minimum
impacts downstream. |
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