A Machine Learning Approach to Map the Poor and Non-Poor Buildings in
Developing Countries
Abstract
The most reliable way to develop poverty maps is through household
surveys. However, in many developing countries, economic data from
household surveys are infrequent. As a result, a data gap has emerged,
making it impossible to identify and understand the locations of poor
people. New approaches that integrate household survey data with
non-traditional data sources (such as satellite imagery, call records,
Wikipedia, google street view) using machine learning allows for
improved resolution and scale in poverty mapping. Nevertheless, these
studies developed poverty maps for study areas located in the same
geographical region and did not map the location of poor people at the
finest level (building level). Integrating income level from household
survey data and building footprints from OpenStreetMap data with
high-resolution satellite imagery, we extract the building rooftop
images and classify them into two classes as poor(< =
$5.50/day) and non-poor(> $5.50/day) based on the
international poverty lines given by the world bank. We use these
rooftop images as training data, develop a deep learning classification
model, and estimate whether a building is poor or non-poor. We use
physical factors like building area, elevation with rooftop images for
transfer learning to contribute to the model’s accuracy. We attempt to
build a versatile model that maps the locations of poor and non-poor
people at the building level by developing, calibrating, and validating
the model for Myanmar, Thailand, and Nicaragua study areas. Our findings
show that for the model to travel well intra-regionally and
inter-regionally, the study areas should be from the same geographical
regions with similar roof types and percentages of people living in
poverty. Combining the rooftop with income level is a fitting parameter
to measure poverty, and roof color plays a crucial role along with the
roof texture, shape to increase the model’s accuracy. The proposed
methodology helps develop poverty maps for different income levels
($1.90, $3.20, $21.70, or any desired income level) from limited
household survey data. This research study identifies the location and
the total number of poor households living in a specific region which
helps plan for effective poverty reduction, urban planning, and disaster
prevention tailored to local conditions.