NIGHT-SKY BRIGHTNESS IN BURKINA FASO: OUAGADOUGOU LIGHT POLLUTION ASSESSMENT AND IMPACT ON THE STARRY SKY OBSERVATION .

The quest for well-being and improvement of the populations living conditions in the borders of the big cities have changed habits in terms of lighting. The use of LED lamps and the reduction in the cost of photovoltaic panels, have allowed easy access to electricity nowadays. The lack of education on the nature of outdoor lighting has unfortunately led to an increase of light pollution.This study uses VIIRS DNB Free Cloud Composites imagery to perform light pollution in Burkina Faso mainly in Ouagadougou, the main cities and surrounding areas. VIIRS imagery data obtained have been processed to get information of light pollution by classifying the information into several classes presented in a map.Using VIIRS images, we show that light pollution has increased by 20% in Burkina Faso in major cities such Ouagadougou. Despite the fact that the illuminated surface per thousand inhabitants, ~0.09km2, remains almost stable over the years. Areas of the city experience a decrease (<1%/year) in nighttime light while some areas have an explosion up to 50nW/cm2sr a year due to the presence of new infrastructure.Light pollution increases inside the city and the observation of the night sky becomes quite difficult in the inner city and still feasible on the outskirts of these cities.