Table 3

Features of slums

DomainItemHousehold surveyGround survey for features of an areaEarth observationComment
Built environmentDurability of construction materials+++++++++Spectral analysis can be used to get some idea of roof materials (especially with ultra-high resolution)
Layout of lanes and orientation of structures—degree of entropy+++++++++Earth observation images can be used to quantify this characteristic, for example, using advanced image feature extraction and classification methods such as machine learning
Density, for example, people sleeping in same room/people per square km++++++Clearly, this must be a proxy measurement unless based on household survey
ServicesWater+++++++
(hard to quantify)
Sanitation++++++++Open sewers discernible on very-high-resolution images
Power++++++++Use of night-time light images allow to detect availability of street lighting but the resolution is limited25
Solid waste management++++++++++
Health and education facilities+++++++
EcologyFlood plain++++++
Probability of subsidence++++++Amount of subsidence can be measured accurately from space with radar-based interferometry
Green and blue space+++++++
Socioeconomic (social exclusion)Security of tenure/title++++
Level of poverty++++++(++)The extent to which earth observation images may be a proxy is unknown28
Crime and safety++++
Social capital+++++