A surrogate machine learning model to improve flood depth estimation using OWP-HAND FIM depth products and other hydrological attributes.

The process_data.py script prepares the input raster data for model training and evaluation by performing the following key steps:

• Reads and flattens raster data for each HUC8 watershed and return period.
• Cleans and normalizes rasters, handling NoData values.
• Computes derived features like aspect_sin and aspect_cos.
• Ensures consistent shape alignment across all rasters.
• Balances the dataset by limiting zero flood depth values to match the count of non-zero values (1:1 ratio).
• Performs a stratified train-test split (default: 70% train, 30% test).
• Saves:
  • One combined train.pkl file for all training data.
  • Separate *_test.pkl files for each HUC8 and return period.

python process_data.py --input ../data/ --output ../data_processed/

• --input: Path to the base directory containing raster data folders.

• --output: Output directory where the processed .pkl files will be saved.

• --test_size: (Optional) Proportion of test data. Default is 0.3.

data_processed/
│
├── train.pkl                    # Combined, balanced training dataset
│
├── <HUC8>/
│   ├── 10year_test.pkl
│   ├── 50year_test.pkl
│   └── ...

• Balancing is applied before splitting to reduce data volume and speed up training.
• Only raster pairs with valid and aligned shapes are included.