Fluctuations in anthropogenic nighttime lights from satellite imagery for five cities in Niger and Nigeria

Abstract

Dynamic measures of human populations are critical for global health management but are often overlooked, largely because they are difficult to quantify. Measuring human population dynamics can be prohibitively expensive in under-resourced communities. Satellite imagery can provide measurements of human populations, past and present, to complement public health analyses and interventions. We used anthropogenic illumination from publicly accessible, serial satellite nighttime images as a quantifiable proxy for seasonal population variation in five urban areas in Niger and Nigeria. We identified population fluxes as the mechanistic driver of regional seasonal measles outbreaks. Our data showed 1) urban illumination fluctuated seasonally, 2) corresponding population fluctuations were sufficient to drive seasonal measles outbreaks, and 3) overlooking these fluctuations during vaccination activities resulted in below-target coverage levels, incapable of halting transmission of the virus. We designed immunization solutions capable of achieving above-target coverage of both resident and mobile populations. Here, we provide detailed data on brightness from 2000–2005 for 5 cities in Niger and Nigeria and detailed methodology for application to other populations.

Investigating persistent measles dynamics in Niger and associations with rainfall

“…The significant association with the rainy season likely reflects the impact of shifting human activities. It is consistent with what is expected in countries with agriculturally driven economies: fluctuating population densities as seasonal agricultural labourers transition between urban and rural areas, creating a strong seasonal forcing in transmission [15,22]. This is another facet of the phenomenon captured by the strong regularity of the annual periodicity and further supports the theory that an intervention focusing on this mobile population could strongly impact measles transmission in Niger.…”

“…The West African nation of Niger reported high measles mortality in recent years [21] and presents strong seasonality, similar to classical England and Wales measles dynamics, though in Niger the seasonal forcing is due to agricultural activity [16,17,22]. Additionally, the connectivity of the population in Niger with that of countries with suboptimal vaccination coverage, such as Nigeria [23], provides potential avenues of measles spread.…”

A high-resolution gridded dataset to assess electrification in sub-Saharan Africa

“…Nighttime lights have already been used as a proxy for electricity access 28–31 , residential consumption 32–37 , outages detection 38–40 , population fluctuations and migration 41,42 , regional GDP 43,44 and income inequality 45 . This is, however, the first time a fully reproducible and updatable dataset at this high level of resolution has been constructed and validated for SSA.…”

It’s risky to wander in September: modelling the epidemic potential of Rift Valley fever in a Sahelian setting

“…Indeed, their temporal dynamics, mostly driven by animal mobility, is not incorporated into GLW 3 data, and might affect the population-specific contact rate with vectors and therefore R 0 values. Remote-sensing methods are considered a promising tool to measure human mobility (Bharti and Tatem, 2018), but we also need qualitative data on factors guiding decisions of nomadic herders in order to include animal mobility in a mechanistic way (Apolloni et al, 2018; Belkhiria et al, 2019).…”