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| Titel |
Stochastic runoff connectivity (SRC) equations: integration with erosion models for water quality prediction |
| VerfasserIn |
G. Sheridan, O. D. Jones, H. Smith, J. Cawson, P. J. Lane |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250031527
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| Zusammenfassung |
| In a companion paper at this conference a single-event steady-state rainfall-runoff model
(including runoff-runon phenomena) is derived that quantifies the effect of the random spatial
arrangement of rainfall and soil properties on i) infiltration-excess runoff delivery at a
downslope boundary, and ii) the distribution of the “connected length” (the upslope length
with a continuous runoff pathway adjacent to the stream boundary). The accumulation and
loss of runoff down a slope is represented as a first-in first-out (FIFO) GI/G/1 queuing
system. Runoff rate at a downslope boundary is analogous to the waiting time in the queue in
this representation. The distribution of connected length can be represented analytically as a
FIFO M/M/1 queuing system, and the mean and variance is derived for this property.
Together these distributions characterise the degree of connectivity of the overland flow
pathway (and by extension its associated pollutant load) for a given set of rainfall and soil
conditions.
In this poster, the stochastic runoff connectivity (SRC) model is developed further. We show
how the probabilistic SRC model outputs i) and ii) above can be integrated with
physically based hillslope scale surface erosion models to predict the probability
distribution of constituent (sediment, phosphorous, etc) delivery to the stream boundary.
The performance of the model is compared to 2 years of multi-length erosion plot
data, and 3 years of continuous small catchment export data from SE Australian
forests. |
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