The risk index we provide has been obtained after a deep analysis of several variables influencing malaria outbreaks: rain, temperature, vegetation index, humidity, soil moisture etc. A minimum rain rate and temperature range between 18 and 30 ºC are considered as trigger variables to possible vectors, but the intensity is modulated by other variables derived from rain and temperature, such as vegetation index, NDVI, or relative humidity, which evolve smoothly. The risk thresholds have been determined after analysis of years 2010, 2011, 2012 and 2013.
Soil temperature and NDVI are obtained from MODIS images. Meteorological variables are obtained by means of WRF model. The risk index is obtained by averaging the last eight days data.
Ref: Silvia Fraile, Desarrollo de un índice de riesgo de malaria en Tanzania mediante observación espacial y previsión meteorológica. Ph. D. University of Valladolid, Spain, 2015.