Deterioration processes and modelling in urban drainage systems

This chapter discusses and assesses processes underlying the loss of functionality of (elements) of urban drainage systems. The chapter does not pretend to cover all literature nor do the authors claim to cover all processes involved. As the body of literature experiences a rapid growth, the authors want to provide the reader a comprehensive overview of the literature to-date to be used as an entry for further exploration. Several processes are described and the possibility to model them in a deterministic manner is discussed. The last sections provide a brief introduction to the use of statistical models based on condition classes (as is applied in practice) along with a brief overview of advancements made in machine learning applications.