Scientific hydrological concepts, illustrated

Context

This is an ongoing illustration project for “Hydrology – unified principles and practices across scales,” a textbook to be published by Wiley.

The authors are among the most influential figures in modern hydrology. Günter Blöschl (TU Wien) holds the AGU’s Robert E. Horton Medal and has shaped how we understand flood change across Europe through landmark papers in Nature and Science. Murugesu Sivapalan (University of Illinois) co-founded the field of socio-hydrology and led the IAHS Decade on Predictions in Ungauged Basins. Both he and Blöschl received the AGU Horton Medal and the EGU Wegener Medal. Peter Troch (University of Arizona) has advanced hillslope hydrology and catchment-scale water balance theory. Together, they have defined modern scaling concepts in hydrology, that is, how processes observed at one scale translate to another.

The book spans 15 chapters and requires more than 500 figures. The authors provide rough drafts (sometimes hand-drawn sketches, sometimes legacy diagrams from older publications), and I work directly with them to interpret and transform these into publication-quality scientific figures. The collaboration is iterative and driven by the concepts behind each figure.

Final Draft

Approach

The scale of the project demanded a production system beyond my drawing skills, built on an entirely open-source toolchain.

2D schematics (process diagrams, hillslope cross-sections, soil-plant interactions) are drawn in Inkscape. 3D schematics (terrain renders, subsurface layers, catchment-scale landscapes) go through Blender and QGIS. Maps come from QGIS and Inkscape. Global maps were a particular challenge, since source data wasn’t always consistent, so several were reconstructed from RGB classification to keep a unified palette. Python scripts tie the system together, automating repetitive tasks and managing a figure catalog through Markdown metadata files.

All figures follow a unified design system (consistent fonts, spacing, line weights, and a controlled set of color palettes), which makes the 500+ figures look like they belong to the same book.

One of the harder aspects is interpreting the drafts themselves. Some are clear; others require real hydrological knowledge to decode: a rough sketch of a hillslope process might imply three or four interacting mechanisms that need to be visually separated and made legible. I have to understand the hydrology before drawing the figure.

Final Draft

Final Draft

Outcomes

Beyond the figures, the project produced several companion tools and deliverables.

Galley Proof website. This is a private review platform hosted on Cloudflare: authors get access codes by email and can browse, approve, and comment on figures by chapter, so review happens in one place instead of scattered email threads. Its static companion, the figure catalog, is a LaTeX-built PDF reference of all figures and metadata.

LaTeX manuscript system. A secondary deliverable for the authors: tooling enforcing consistency in symbol notation, formatting, and cross-references across 15 chapters, plus guides for the figure workflow and the LaTeX system, both delivered as PDFs.

The book is in production, figures delivered chapter by chapter. After publication, they’re expected to go public for instructors and students to use in lectures and course materials.