Estimating the size of urban populations using Landsat images: a case study of Bo, Sierra Leone, West Africa.

Background: This is the third paper in a 3-paper series evaluating alternative models for rapidly estimating neighborhood populations using limited survey data, augmented with aerial imagery.

Methods: Bayesian methods were used to sample the large solution space of candidate regression models for estimating population density.

Results: We accurately estimated the population densities and counts of 20 neighborhoods in the city of Bo, Sierra Leone, using statistical measures derived from Landsat multi-band satellite imagery.

Health-care availability, preference, and distance for women in urban Bo, Sierra Leone.

Objectives: To examine the diversity of the health-care providers in urban Bo, Sierra Leone, identify the types of health-care facilities preferred by women for fevers, and analyze the road network distances from homes to preferred health-care providers.

Methods: A population-based random sampling method was used to recruit 2419 women from Bo. A geographic information system was used to measure the road distance from each woman's home to her preferred provider.

Stratified Sampling of Neighborhood Sections for Population Estimation: A Case Study of Bo City, Sierra Leone.

There is a need for better estimators of population size in places that have undergone rapid growth and where collection of census data is difficult. We explored simulated estimates of urban population based on survey data from Bo, Sierra Leone, using two approaches: (1) stratified sampling from across 20 neighborhoods and (2) stratified single-stage cluster sampling of only four randomly-sampled neighborhoods. The stratification variables evaluated were (a) occupants per individual residence, (b) occupants per neighborhood, and (c) residential structures per neighborhood.

Methods for determining the uncertainty of population estimates derived from satellite imagery and limited survey data: a case study of Bo city, Sierra Leone.

This study demonstrates the use of bootstrap methods to estimate the total population of urban and periurban areas using satellite imagery and limited survey data. We conducted complete household surveys in 20 neighborhoods in the city of Bo, Sierra Leone, which collectively were home to 25,954 persons living in 1,979 residential structures. For five of those twenty sections, we quantized the rooftop areas of structures extracted from satellite images.