What you will find here

Watershed Modeling is a focused reference for automating hydrologic workflows in Python. Every page is built around concrete, reproducible patterns: which library to reach for, why a routing algorithm behaves the way it does on a given terrain, and how to wrap it in a defensible pipeline with logging, idempotency, and topology validation.

Whether you are moving from desktop GIS to a code-driven pipeline, integrating LiDAR into an operational workflow, or scaling watershed delineation across a continent of tiles, the content here favours the algorithmic depth and engineering rigour that production agency-grade work demands — not surface-level tutorials.

The collection now runs to 84 pages across four sections and 22 topic areas, every one of them carrying runnable Python, a validation protocol that can fail, and hand-authored diagrams of the mechanism being described. Recent additions cover hydro-conditioning through road embankments, stream-network vectorization and ordering, tiled processing for datasets larger than memory, design-storm construction, and flood-frequency and low-flow statistics from gauge records.

Start here

New to automated watershed modeling? These guides establish the foundation — from acquiring your first DEM to producing a validated stream network and simulating the runoff hydrograph it drains.

  1. How to Download SRTM DEMs for Python Hydrology Workflows Data acquisition · SRTM · OpenTopography API
  2. Best Practices for Filling Sinks in High-Resolution LiDAR Data DEM conditioning · Priority-flood · Hydro-enforcement
  3. Implementing D8 Flow Routing with RichDEM Python Bindings Flow direction · RichDEM · D8 algorithm
  4. Tuning Flow Accumulation Thresholds for Ephemeral Streams Stream extraction · Threshold calibration · WhiteboxTools
  5. Partitioning Large Watersheds into Sub-Basins with RichDEM Basin partitioning · Sub-catchments · Scalable pipelines
  6. SCS Curve Number Runoff Estimation Rainfall-runoff · NRCS curve number · Excess rainfall
  7. Hydro-Conditioning for Culverts and Road Crossings Conditioning · Breaching · Why finer DEMs make roads worse
  8. Stream Network Vectorization and Ordering Segments · Topology · Strahler and Shreve order
  9. Precipitation Forcing and Design Storms Areal reduction · Alternating block · SCS type curves

All topics

All 84 pages, organised by section and topic. Jump directly to the technique or pipeline stage you need — conditioning, routing, delineation, forcing, calibration or statistics.