Status : Verified
| Personal Name | Bilaro, Virgil B. |
|---|---|
| Resource Title | Flood Modeling under Nonstationarity in the Bicol Region |
| Date Issued | 2024 |
| Abstract | This study focused on the development of nonstationary flood frequency models of two ungauged and four gauged urban watersheds in the Bicol Region. Long-term rainfall and land cover data were analyzed for trends and were subsequently used to reconstruct historical streamflow using deterministic and stochastic techniques. The continuous streamflow models were developed with static and time-evolving built-up land cover area to mimic the effect of land cover change brought about by urbanization. Annual flood maximum series were developed from each historical streamflow data set and were tested for trends. The models with time-evolving built-up landcover area or with urbanization as co-predictors were able to generate continuous streamflow time series that yielded flood extremes exhibiting nonstationarity, coincidentally, for watersheds with significantly increasing urbanization trends. The annual flood maxima were fitted onto stationary and nonstationary GEV distribution models using Bayesian approach and successively tested for goodness-of-fit and parsimony. All the annual flood series from both deterministic and stochastic models satisfactorily fit both the stationary and nonstationary GEV distribution, with the stationary models exhibiting better fit for streamflow models of watersheds with no significant urbanization trend; and the nonstationary models exhibiting better fit for streamflow models of watersheds with significantly increasing urbanization trend. The probability of exceedance of floods through some threshold magnitude increases under the nonstationary framework for all watersheds when urbanization is used as covariate for both deterministic and stochastic models. Consequently, the risk of failure when nonstationarity is considered is comparatively higher than when stationarity is assumed. |
| Degree Course | Doctor of Philosophy in Civil Engineering |
| Language | English |
| Keyword | Nonstationarity; Risk and reliability; Return period; Extreme value distribution; Flood frequency; Streamflow model |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : F - Regular work, i.e., it has no patentable invention or creation, the author does not wish for personal publication, there is no confidential information.
Access Permission : Open Access