Two-step floating catchment area method

Two-step Floating Catchment Area Method

The Two-step Floating Catchment Area (2SFCA) method is a spatial accessibility measure used in geographic information systems (GIS) to assess the accessibility of services, such as healthcare facilities, within a given area. It is particularly useful in public health and urban planning to evaluate the distribution of services relative to the population.

Overview

The 2SFCA method is designed to measure the accessibility of services by considering both the supply of services and the demand from the population. It is a two-step process that calculates accessibility scores for different locations based on the proximity and capacity of service providers.

Methodology

The 2SFCA method involves the following steps:

Step 1: Catchment Area of Service Providers

In the first step, a catchment area is defined around each service provider. This catchment area is typically determined by a specified distance or travel time, such as a 30-minute drive time. Within this catchment area, the population that can potentially access the service is identified. The service-to-population ratio is then calculated for each service provider by dividing the capacity of the service (e.g., number of hospital beds) by the total population within the catchment area.

Step 2: Catchment Area of Population Locations

In the second step, a catchment area is defined around each population location, such as a residential area. The service providers within this catchment area are identified, and the service-to-population ratios calculated in Step 1 are summed to obtain an accessibility score for each population location. This score reflects the overall accessibility of services for the population at that location.

Applications

The 2SFCA method is widely used in various fields, including:

• Healthcare Accessibility: To evaluate the accessibility of healthcare facilities, such as hospitals and clinics, for different populations.
• Urban Planning: To assess the distribution of public services and infrastructure in urban and rural areas.
• Transportation Planning: To analyze the accessibility of transportation networks and services.

Advantages and Limitations

Advantages

• Simplicity: The 2SFCA method is relatively simple to implement and interpret compared to more complex spatial accessibility models.
• Flexibility: It can be adapted to different types of services and geographic contexts by adjusting the catchment area parameters.

Limitations

• Assumptions: The method assumes that all individuals within a catchment area have equal access to services, which may not reflect real-world conditions.
• Static Analysis: It provides a static measure of accessibility and does not account for temporal variations in service availability or demand.

See Also

• Geographic Information System
• Spatial Analysis
• Healthcare Accessibility