Rare natural hazards (for example, storm surge and hurricanes) can cause loss of lives and devastating damage to society and the environment. For instance, Hurricane Katrina (2005) caused over 1,500 deaths and total estimated damages of $75 billion in the New Orleans area and along the Mississippi coast as a result of storm surge. Uncertainty quantification (UQ) has been used widely to understand, monitor, and predict these rare natural hazards. The Gaussian process (GP) modeling framework is one of the most widely used tools to address such UQ applications and has been studied across several areas, including spatial statistics, design and analysis of computer experiments, and machine learning. With the advance of measurement technology and increasing computing power, large numbers of measurements and large-scale numerical simulations at increasing resolutions are routinely collected in modern applications and have given rise to several critical challenges in predicting real-world processes with associated uncertainty. While GP presents a promising route to carrying out UQ tasks for modern emerging applications such as coastal flood hazard studies, existing GP methods are inadequate in addressing several notable issues such as computational bottleneck due to big datasets and spatial heterogeneity due to complex structures in multi-dimensional domains. This project will develop new Bayesian GP methods to allow scalable computation and to capture spatial heterogeneity. The new