| Summary: | 碩士 === 國立成功大學 === 水利及海洋工程學系 === 85 === It has been known that hydrological processes (e.g.,
precipitation, infiltra-tion,... , etc.) over basin are
heterogeneous. Traditionallumped rainfall-runo-ff models ignore
the spatial heterogeneity ofhydrological processes. To simula-te
hydrological heterogeneity over basin, distributed rainfall-
runoff models w-ere used in this study, in which global
optimization technique was applied for model calibration. The
validation from three storm events concluded that the d-
istributed model has the ability to simulate the
historicalrainfall-runoff rel-ationship. However, the model may
be applied tostorm events outside of the range of conditions for
which the model has been successfully calibrated and verified.
In order to examine the error of model output caused by
parameters uncertain-ty, four methods, including, Monte Carlo
Method (MCM), Latin Hypercube Sampling Technique, Rosenblueth*s
Point Estimation Method and Harr*s Point Estimation Method, were
used in the study and build 95% confidence interval of
estimatedhydrograph. From the comparison of four methods, Latin
Hypercube Sampling Techn-ique has similar analysis results as
Monte Carlo Method has. The variances esti-mated from
Rosenblueth*s Point Estimation Method and Harr*s Point
Estimation M-ethod are larger than that from MCM. Thesensitivity
of three model parameters, overland flow storage parameter (Ks),
channel storage parameter (Kc) and initi-al infiltration rate
correcting parameter (CH), were further examined by local and
global methods. CH was found to be more sensitive than the other
model para-meters. In order toreduce model errors caused by CH
parameter, which is the mo-st sensitive parameter in the model,
building the relationship between CH and physical properties
over basin is studied. The CH parameter was found to have g-ood
relation with 5-day average flow before the event. The model
performance w-as concluded from three storms that using CH
derived by 5-day average flow bef-ore storm to replace average
values of CH parameter from 6 calibration storms c-an improve
the results of hydrograph simulation.Kekeywords : distributed
rainfall-runoff model, uncertainty, sensitivity analysis.
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