# CHW 3.0 Logic dataset

## Core metadata

Dataset file name: chw_3_0_logic.csv
Dataset name: Coastal Hazard Wheel 3.0 (machine-readable)
dataset_id: chw_3_0_logic
Purpose: Coastal Hazard Wheel 3.0 coastal classification logic table (machine-readable) for screening-level assessment and decision support.
Version: 3.0.0
Release date: 2026-02-21
License: CC BY 4.0 (Creative Commons Attribution 4.0 International)
Canonical source: https://www.coastalhazardwheel.org/chw-dataset/

## Primary key and joins

Primary key: chw_code
Join to: chw_3_0_hazard_management_matrix.csv on chw_code
Relationship: one-to-one

## Table structure

Table file: chw_3_0_logic.csv

Classification dimension fields (strings):
- geological_layout
- wave_exposure
- tidal_range
- flora_fauna
- sediment_balance
- storm_climate_tropical_cyclone_activity

Hazard level fields (integers 1-4):
- ecosystem_disruption
- gradual_inundation
- salt_water_intrusion
- erosion
- flooding

Hazard scale (values):
- 1 = low
- 2 = moderate
- 3 = high
- 4 = very_high
Values are an ordinal screening scale (relative hazard level), not a probability or return period.

## Allowed values (dimension value_id)

geological_layout:
- barrier
- coral_island
- delta_low_estuary_island
- flat_hard_rock
- sediment_plain
- sloping_hard_rock
- sloping_soft_rock
- tidal_inlet_sand_spit_river_mouth

wave_exposure:
- any
- exposed
- moderately_exposed
- protected

tidal_range:
- any
- micro
- meso_macro

flora_fauna:
- any
- corals
- intermittent_mangrove
- intermittent_marsh
- mangrove_tidal_flat
- marsh_mangrove
- marsh_tidal_flat
- no
- non_vegetated_slope
- vegetated_slope

sediment_balance:
- any
- balance_deficit
- beach
- no_beach
- surplus

storm_climate_tropical_cyclone_activity:
- any
- yes
- no

Meaning of "any":
- "any" means the dimension does not filter/constrain the CHW type for that row.
- "any" is not missing/unknown data.

## Lookups

Dimensions lookup: dimensions_lookup_chw3_0.csv
Hazards lookup: hazards_lookup_chw3_0.csv

## Dataset size

Rows (CHW types): 131
Columns (including chw_code): 12

## Packaging

Files included:
- chw_3_0_logic.csv
- dimensions_lookup_chw3_0.csv
- hazards_lookup_chw3_0.csv
- README.md
- README_chw_3_0_logic.md

File format:
- UTF-8 CSV
- comma delimiter
- header row included

Expected data types:
- chw_code and all IDs are strings
- classification dimension fields are strings
- hazard level fields are integers (1-4)

Missingness rule:
- "any" is a valid value meaning "dimension does not filter/constrain"
- no blank values are expected for classification dimensions