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| Titel |
Can we improve streamflow simulation by using higher resolution rainfall information? |
| VerfasserIn |
Florent Lobligeois, Vazken Andréassian, Charles Perrin |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250082083
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| Zusammenfassung |
| The catchment response to rainfall is the interplay between space-time variability of
precipitation, catchment characteristics and antecedent hydrological conditions. Precipitation
dominates the high frequency hydrological response, and its simulation is thus dependent on
the way rainfall is represented.
One of the characteristics which distinguishes distributed from lumped models is their
ability to represent explicitly the spatial variability of precipitation and catchment
characteristics. The sensitivity of runoff hydrographs to the spatial variability of forcing data
has been a major concern of researchers over the last three decades. However, although the
literature on the relationship between spatial rainfall and runoff response is abundant,
results are contrasted and sometimes contradictory. Several studies concluded that
including information on rainfall spatial distribution improves discharge simulation
(e.g. Ajami et al., 2004, among others) whereas other studies showed the lack of
significant improvement in simulations with better information on rainfall spatial
pattern (e.g. Andréassian et al., 2004, among others). The difficulties to reach a
clear consensus is mainly due to the fact that each modeling study is implemented
only on a few catchments whereas the impact of the spatial distribution of rainfall
on runoff is known to be catchment and event characteristics-dependent. Many
studies are virtual experiments and only compare flow simulations, which makes it
difficult to reach conclusions transposable to real-life case studies. Moreover, the
hydrological rainfall-runoff models differ between the studies and the parameterization
strategies sometimes tend to advantage the distributed approach (or the lumped
one).
Recently, Météo-France developed a rainfall reanalysis over the whole French territory at
the 1-kilometer resolution and the hourly time step over a 10-year period combining radar
data and raingauge measurements: weather radar data were corrected and adjusted with both
hourly and daily raingauge data. Based on this new high resolution product, we
propose a framework to evaluate the improvements in streamflow simulation by using
higher resolution rainfall information. Semi-distributed modelling is performed for
different spatial resolution of precipitation forcing: from lumped to semi-distributed
simulations. Here we do not work on synthetic (simulated) streamflow, but with actual
measurements, on a large set of 181 French catchments representing a variety of size and
climate. The rainfall-runoff model is re-calibrated for each resolution of rainfall
spatial distribution over a 5-year sub-period and evaluated on the complementary
sub-period in validation mode. The results are analysed by catchment classes based on
catchment area and for various types of rainfall events based on the spatial variability of
precipitation.
References
Ajami, N. K., Gupta, H. V, Wagener, T. & Sorooshian, S. (2004) Calibration of a
semi-distributed hydrologic model for streamflow estimation along a river system. Journal of
Hydrology 298(1–4), 112–135.
Andréassian, V., Oddos, A., Michel, C., Anctil, F., Perrin, C. & Loumagne, C. (2004)
Impact of spatial aggregation of inputs and parameters on the efficiency of rainfall-runoff
models: A theoretical study using chimera watersheds. Water Resources Research 40(5), 1–9. |
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