Hydrology and climatology are two closely related branches of earth science. Almost all variables in hydrological and/or climatological processes exhibit certain degree of randomness. Either from a scientific or engineering point of view, understanding and characterizing the random nature of hydroclimatic processes enables us to make sound decisions for water management and disaster prevention. In this course, students will learn step by step from characterizing and simulating a single random variable to simulation of a spatiotemporal random field which is composed of many correlated random variables in space and in time. Stochastic simulation will be highly emphasized in class since it is the foundation for probability-based risk assessment. Familiarity of stochastic simulation will open a wide window of potential research subjects and applications to students.