Vector-based Approach

This page explains how to use DamageScanner with vector-based exposure data (e.g. shapefiles, GeoPackages, or OSM data). This approach is ideal for object-level damage estimation, such as buildings, roads, power plants, and other individual infrastructure assets.

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When to Use Vector-Based Workflows

Scenario	Raster-Based	Vector-Based
Infrastructure objects (e.g. bridges, roads)	❌	✅
OpenStreetMap data	❌	✅
Detailed local studies	❌	✅
Exposure linked to specific geometries	❌	✅

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Required Inputs

As described in the Overview, you need:

1. Hazard raster (e.g. flood depth, wind speed)
2. Exposure vector (e.g. buildings, roads — as .shp, .gpkg, .pbf, or GeoDataFrame)
3. Vulnerability curves (CSV or DataFrame)
4. Maximum damage values (CSV, dict, or DataFrame)

For a detailed walkthrough with real data and visualizations, see our Vector-based example notebook.

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Key Behavior

• The exposure file must contain geometry columns (Point, LineString, or Polygon)
• DamageScanner overlays each geometry with the hazard raster
• It then samples the hazard value and looks up the damage fraction from the corresponding vulnerability curve
• The damage is calculated as:

exposure_area * damage_fraction * max_damage

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📚 See Also

• Overview
• Raster-based approach
• Coupling with OSM

API Documentation

vector

Vector-based damage estimation functions for DamageScanner.

VectorExposure(hazard_file, feature_file, asset_type='roads', object_col='object_type', hazard_value_col='band_data', disable_progress=False, gridded=True, extract_strategy='raster-sequential', return_full=True)

Load and overlay vector or raster hazard with vector exposure data.

Parameters:

Name	Type	Description	Default
hazard_file	Path | Dataset | DataArray | DatasetReader | GeoDataFrame	Hazard input.	required
feature_file	Path | GeoDataFrame | DataFrame | str	Exposure input.	required
asset_type	str | None	Infrastructure category (only for OSM).	'roads'
object_col	str	Name of the object type column.	'object_type'
hazard_value_col	str	Column name in vector hazard containing intensity values.	'band_data'
disable_progress	bool	Whether to suppress progress bars.	False
gridded	bool	Whether to process in spatial chunks.	True
extract_strategy	str	exactextract strategy - "feature-sequential" or "raster-sequential".	'raster-sequential'
return_full	bool	Whether to return all features, even those with no hazard intersection.	True

Returns:

Name	Type	Description
tuple	tuple[GeoDataFrame, str, CRS | None, float | None]	(features, object_col, hazard_crs, cell_area_m2)

Raises:

Type	Description
ValueError	If input files are not in expected formats or if geometry types are unsupported.

VectorScanner(hazard_file, feature_file, curve_path, maxdam_path=None, asset_type=None, multi_curves=dict(), object_col='object_type', hazard_value_col='band_data', disable_progress=False, gridded=True, extract_strategy='raster-sequential', return_full=True)

Perform vector-based direct damage assessment using hazard and exposure layers.

Parameters:

Name	Type	Description	Default
hazard_file	Path | Dataset | DataArray | GeoDataFrame | str	Hazard input.	required
feature_file	Path | GeoDataFrame | str	Exposure input.	required
curve_path	Path | DataFrame | str	Vulnerability curve(s).	required
maxdam_path	Path | DataFrame | dict | None	Maximum damage values.	None
asset_type	str | None	Infrastructure class (only for OSM).	None
multi_curves	dict	Multiple curve sets.	dict()
object_col	str	Column name with object type.	'object_type'
hazard_value_col	str	Column name in vector hazard containing intensity values.	'band_data'
disable_progress	bool	Whether to suppress progress bars.	False
gridded	bool	Whether to process in spatial chunks.	True
extract_strategy	str	exactextract strategy - "feature-sequential" or "raster-sequential".	'raster-sequential'
return_full	bool	Whether to return all features, even those with no hazard intersection.	True

Returns:

Type	Description
GeoDataFrame	Exposure data with calculated damages.

Raises:

Type	Description
ValueError	If input files are of unsupported formats or if geometry types are not supported.
KeyError	If object types in exposure are not covered by maximum damage data.