Prepare Input Data

NoteAt a glance
  • Input: Source layers in data/01_inputs/source/
  • Output: Analysis-ready GeoPackages and GeoTIFFs in data/01_inputs/prepared/ at EPSG:32604
  • Helper: src/prepare_input_layers.py

Goal

The notebook reprojects, mosaics, and converts the source layers into a single set of analysis-ready files at a common CRS. Outputs feed every downstream notebook.

Inputs

All staged source layers from the Download Datasets step.

Outputs

All prepared layers land in a single folder at the target CRS.

  • Prepared folder: HiOSDS-TechSuitabilityAnalysis/data/01_inputs/prepared/
  • CRS: EPSG:32604 (UTM Zone 4N)
  • Rasters: rainfall, DEM, slope, watertable
  • Vectors: building footprints, cesspool inventory, coastline, flood zones, parcels, SMA, soils, streams, domestic wells, municipal wells

Processing Steps

The prepare notebook (notebooks/01_prepare_input_layers.ipynb) follows five steps:

  1. Import modules and helper functions. The notebook pulls preparation utilities from src/prepare_input_layers.py and loads ArcPy plus the standard geospatial stack.
  2. Specify configurations. The target CRS (EPSG:32604) is set here.
  3. Specify project and data directory paths. Paths point at the source, prepared, and interim directories.
  4. Build file paths to each source input and matching output. A pair of dictionaries (source_inputs, prepared_outputs) maps each layer name to its source file and its prepared GeoPackage or GeoTIFF target.
  5. Prepare all or individual layers. A single function call processes every layer in the dictionaries. Already-prepared layers are skipped automatically. Individual cells at the bottom of the notebook can re-run a single layer when the source has changed.

Notes and Decisions

  • Target CRS. All prepared layers use EPSG:32604 (UTM Zone 4N). The analysis depends on distances and areas, so projected coordinates are used instead of geographic coordinates.
  • Domestic and municipal wells. The source wells layer contains both well types. The prepare step splits them into domestic and municipal GeoPackages so the screening notebook can compute separate setbacks and then use the nearest well distance.
  • Building footprints. Maui, Kauai, and Oahu building footprint sources are merged into one prepared layer. The source island is retained for traceability.

Resources