CA Valley Floors

A Python-based workflow for generating high-resolution valley floor polygons across California using 10m Digital Elevation Models (DEMs) and National Hydrography Dataset (NHD) flowlines.

Overview

This project uses valleyx to extract valley floor boundaries from:

• USGS 3DEP 10-meter Digital Elevation Models
• NHD Medium Resolution Flowlines

The workflow processes data by Hydrologic Unit Code (HUC) regions, allowing for flexible regional analysis and parallel processing.

Features

• Automated downloading of DEM and flowline data
• Parallel processing support through Snakemake
• Configurable parameters for valley floor extraction
• Tools for mosaicking and clipping results
• California-specific boundary and ocean clipping

Prerequisites

• Python 3.10 or higher
• Poetry for dependency management
• Git for version control

Installation

1. Clone the repository:

git clone [email protected]:avkoehl/ca-valley-floors.git
cd ca-valley-floors

2. Install dependencies:

# Basic installation
poetry install

# With development tools (matplotlib, jupyter)
poetry install --with dev

Configuration

Basic Setup

1. Copy and edit the configuration file:

cp config.yaml my_config.yaml

2. Configure the output directory in my_config.yaml:

output_base: '/path/to/your/output/directory/'

HUC Selection

The workflow supports three methods for selecting HUC regions (configure only one):

1. Single HUC:

huc_id: '18050002'

2. Multiple specific HUCs:

huc_ids:
  - '1802016306'
  - '1804001211'

3. HUC manifest file:

huc_manifest: './data/target_huc10s.csv'
prefix: '18'          # Optional: Filter by prefix
sample_size: 5        # Optional: Sample size
random_seed: 14       # Optional: Random seed

Workflow Steps

1. Data Preparation

Download DEMs and flowlines:

poetry run snakemake prep_all --configfile my_config.yaml -j 10 --resources download_slots=10

2. Valley Floor Extraction

If its the first time, initialize whitebox tools:

poetry run snakemake initialize_whitebox

Process the downloaded data:

poetry run snakemake extract_all --configfile my_config.yaml -j 10

3. Results Processing

Option A: California-specific mosaic

Mosaic results and clip to California boundary (includes ocean clipping):

poetry run snakemake mosaic_ca

Option B: General mosaic

Mosaic results with ocean clipping only:

poetry run snakemake mosaic

Customizing Valley Floor Parameters

1. Create a custom parameters file:

cp params/params_10m.toml params/my_params.toml

2. Update the configuration to use your parameters:

params_file: 'params/my_params.toml'

Project Structure

ca-valley-floors/
├── config.yaml          # Main configuration file
├── params/             
│   └── params_10m.toml  # Valley floor extraction parameters
├── data/                # Input data directory
└── README.md           

Support

For questions or issues, contact:

• Arthur Koehl
• Email: avkoehl at ucdavis.edu