Data Overview Walkthrough#

Beginner30 mindatahydrography

This is the default first HydroModPy workflow if you want to understand how one basin is assembled before touching meshing or solving.

Important

Start here unless you already know that you need a full solver run on day one.

What this workflow teaches#

  • Extract one watershed from outlet coordinates.

  • Build the domain support and depth model.

  • Load the main geographic data layers that later workflows reuse.

  • Produce readable basin-context figures without running a groundwater solver.

Run it#

The TOML declares [workflow].mode = "overview" so the same hmp run entry point dispatches to the data-only pipeline:

hmp run examples/projects/04_data_overview/project.toml

A second variant uses the Nançon catchment with two configs (full overview and a hydrography-only slice):

hmp run examples/projects/05_nancon_data_overview/config_overview.toml
hmp run examples/projects/05_nancon_data_overview/config_hydrography_only.toml

How the files relate#

  • examples/projects/04_data_overview/project.toml is the case definition. It declares [workflow].mode = "overview" at the top level, so hmp run dispatches to the data-only pipeline (no solver, no mesh).

  • The gallery page Watershed Data Overview republishes stable figures generated from this workflow.

  • The focused hydrography page BD Topage Hydrography Overlay republishes the minimal BD Topage only variant when you want to inspect the river network overlay in isolation.

Read the config in this order#

  1. [geographic]: This section answers one question first: which basin are we extracting and with how much context?

  2. [domain]: Read this next to see which support zones and depth model later workflows would inherit.

  3. [data]: The types list tells you which thematic layers should exist in the result.

  4. Source blocks such as [[data.geology.sources]] or [[data.hydrometry.sources]]: These blocks tell you where each layer comes from and which query window is used.

Parameters to look at first#

  • catch_def, x_outlet, and y_outlet: these define the watershed anchor.

  • snap_dist: this controls how aggressively the outlet is snapped to the drainage network.

  • buff_area: this changes how much surrounding terrain remains visible.

  • zone_ids and depth_model: these define the support that a future mesh or solver would inherit.

  • data.types: this is the fastest switch for simplifying or expanding the workflow.

  • Date windows under hydrometry, intermittency, and oceanic data: these change the observation horizon without changing the basin geometry.

How to read the outputs#

  • Read the DEM-oriented figure first: it tells you whether the basin sits in the expected regional terrain context.

  • Read the local overview second: it tells you which basin-scale overlays are actually available.

  • If the basin extent looks wrong, fix the outlet and snapping settings before editing any downstream modelling section.

  • If an expected overlay is missing, check data.types before assuming a source-specific problem.

First modifications to try#

  • Move x_outlet and y_outlet to a nearby catchment.

  • Change buff_area from 20% to a larger or smaller context window.

  • Remove one entry from data.types to see the workflow slim down.

  • Tighten or widen the date ranges to understand which data layers are purely spatial and which depend on a time window.

Where to go next#

On this page