How to build a digital river

Abstract

There has been an increasing practice of creating Earth-like, realistic synthetic landscapes by Earth scientists and computer scientists for a variety of applications. While together these two fields have made significant scientific and social contributions to creating synthetic landscapes, it is presently infeasible to build artificial digital rivers that represent the diversity found on Earth. To understand and summarize the state of the science of rendering artificial river topography, we reviewed >225 scientific articles and produced a road map for artificial synthesis of digital river topography. We broadly classify methods of digital river synthesis by whether they are driven by expert-based decisions or are strategic in the use of rules for objective rendering, with some rules being physics-based theories of river morphogenesis. Expert approaches include map, brush, geometric and interactive design. Strategic approaches include deterministic equilibrium models, morphodynamic models, and stochastic approaches. For each approach we discuss the conceptual basis for each method and how they can be applied. Readers can then identify what methods can create different types of digital riverscapes. We close by discussing how cross pollination can serve geomorphology and computer science, the role of digital rivers in furthering geoscience progress, and future directions in digital river synthesis.