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Titel |
Assessment of surface water resources availability using catchment modelling and the results of tracer studies in the mesoscale Migina Catchment, Rwanda |
VerfasserIn |
O. Munyaneza, A. Mukubwa, S. Maskey, S. Uhlenbrook, J. Wenninger |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 18, no. 12 ; Nr. 18, no. 12 (2014-12-18), S.5289-5301 |
Datensatznummer |
250120570
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Publikation (Nr.) |
copernicus.org/hess-18-5289-2014.pdf |
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Zusammenfassung |
In the present study, we developed a catchment hydrological model which can
be used to inform water resources planning and decision making for better
management of the Migina Catchment (257.4 km2). The semi-distributed
hydrological model HEC-HMS (Hydrologic Engineering Center – the Hydrologic
Modelling System) (version 3.5) was used with its soil moisture
accounting, unit hydrograph, liner reservoir (for baseflow) and
Muskingum–Cunge (river routing) methods. We used rainfall data from 12
stations and streamflow data from 5 stations, which were collected as part
of this study over a period of 2 years (May 2009 and June 2011). The
catchment was divided into five sub-catchments. The model parameters were
calibrated separately for each sub-catchment using the observed streamflow
data. Calibration results obtained were found acceptable at four stations
with a Nash–Sutcliffe model efficiency index (NS) of 0.65 on daily runoff at
the catchment outlet. Due to the lack of sufficient and reliable data for
longer periods, a model validation was not undertaken. However, we used
results from tracer-based hydrograph separation from a previous study to
compare our model results in terms of the runoff components. The model
performed reasonably well in simulating the total flow volume, peak flow and
timing as well as the portion of direct runoff and baseflow. We observed
considerable disparities in the parameters (e.g. groundwater storage) and
runoff components across the five sub-catchments, which provided insights
into the different hydrological processes on a sub-catchment scale. We
conclude that such disparities justify the need to consider catchment
subdivisions if such parameters and components of the water cycle are to
form the base for decision making in water resources planning in the
catchment. |
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