Applications of the African Flood and Drought Monitor to Vector- and
Water-borne Disease, and to Human Well-being
Abstract
The African Flood and Drought Monitor (AFDM) was developed by Princeton
University in collaboration with UNESCO-IHP, regional hydroclimate
centers in Africa and ICIWaRM. Based on advanced land surface modeling
driven by satellite data, the system provides 25-km resolution
near-real-time evaluations of the terrestrial water cycle, plus
forecasting by merging seasonal climate forecasts with hydrological
modeling. Originally targeted toward hydrometeorological services,
drought managers and researchers, the AFDM has found many applications
in health and epidemiology, e.g.: Malaria: In northern Zambia,
populations of the two malaria-carrying mosquito species had strong,
time-lagged correlations to rainfall events. Relations to temperature
were more complex. The AFDM helped show the effectiveness of targeted
indoor residual spraying (Hast et al., 2019a, b). Trypanosomiasis: In
the Maasai Steppe of Tanzania, negative relationships were found between
abundance of two tsetse fly species and AFDM temperature. Trypanosome
prevalence in the species increased with rising maximum temperatures
from 26-31° C, and then declined (Nnko et al., 2017). Cholera: In
Cameroon, associations were found between AFDM average daily maximum
temperature and risk of cholera transmission that varied across four
climate subzones (Ngwa et al., 2016). Related studies using AFDM data
with implications for human health and well-being in Africa, include:
Stunted growth: In four African countries, a rainfall deficit of 1
standard deviation from the mean was associated with an increase of
stunting in children age 0-60 months of 2.2 to 3.2% (Hill et al.,
2019). Human migration: Rainfall shortages and excess temperature, and
less so soil moisture, are strong drivers of out-migration from South
Africa, especially for black and low-income migrants (Mastrorillo et
al., 2015). Herbivore parasites: In Botswana, temperature had a small
negative effect on abundance of nematode parasites of herbivores (Walker
et al., 2016), and modeled helminth larval development affecting goats
was primarily driven by daily rainfall (Walker et al., 2018). Overall,
these examples provide evidence that the provision of climate and
hydrological information in consistent and accessible ways can help
enable health-related research and applications.