"Spatio-temporal Analysis of Precipitation and Flood Data from South Ca" by Haigang Liu

Author

Haigang Liu

Date of Award

Spring 2019

Document Type

Open Access Dissertation

Department

Statistics

First Advisor

David B. Hitchcock

Abstract

Spatio-temporal data are everywhere: we encounter them on TV, in newspapers, on computer screens, on tablets, and on plain paper maps. As a result, researchers in di- verse areas are increasingly faced with the task of modeling geographically-referenced and temporally-correlated data. In this dissertation, we propose two different spa- tiotemporal models to capture the behavior of rainfall and flood data in the state of South Carolina.

Both models are built using a Bayesian hierarchical framework, which involves specifying the true underlying process in the first level and the spatio-temporal ran- dom effect in the second level of the hierarchy. The prior distribution of the param- eters or hyper-parameters is specified in the third stage. The two models differ in the covariance structure of the spatial random effects. In the rainfall spatiotemporal model, we employ a Gaussian process model which has a distance-based covariance. To model the flood data, we use a conditional autoregressive (CAR) model with a proximity matrix.

Another aspect that sets the models apart is the covariates considered. In particu- lar, the precipitation model incorporates a variable related to sea surface temperature (SST) to reflect the effect of El Niño-Southern Oscillation (ENSO) activity, along with monthly maximum temperature among other predictors. In the flood model, a gridded field of precipitation values with a spatial resolution of roughly 4 × 4 km is used as one of the covariates since investigating the dynamics between the rainfall and flood levels is of interest.

Rights

© 2019, Haigang Liu

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