Loading air quality context...

Diourbel, the capital of the Diourbel Region in Senegal, occupies a geographically significant position within the country’s interior, roughly 150 kilometers east of Dakar. The city’s location is characterized by a gently undulating terrain, part of the Sahelian plain, situated at a modest elevation of around 28 meters above sea level. This relatively flat landscape, while facilitating urban expansion, also contributes to air quality challenges. Diourbel is surrounded by a predominantly agricultural landscape, with extensive millet and groundnut fields dominating the surrounding plains. This agricultural activity, particularly during harvesting and processing seasons, introduces particulate matter into the atmosphere. To the north and west, the landscape gradually transitions to more wooded savanna, while to the east and south, the terrain remains largely agricultural. The absence of significant bodies of water within immediate proximity limits natural air purification processes; there are no major rivers or lakes nearby to facilitate precipitation-driven pollutant removal. While not directly adjacent to an industrial belt, Diourbel serves as a regional market town, attracting trade and transportation, which can contribute to localized emissions from vehicles and associated activities. The urban–rural gradient around Diourbel is relatively gradual, with smaller villages and agricultural settlements blending seamlessly into the urban fabric, influencing the dispersion of pollutants and creating a complex interplay between urban and rural air quality dynamics. The prevailing winds, often originating from the Atlantic coast, can transport pollutants inland, impacting Diourbel’s air quality.

Diourbel experiences a tropical savanna climate, defined by distinct wet and dry seasons, profoundly influencing its air quality profile. The dry season, typically spanning from November to May, is characterized by lower humidity, higher temperatures, and a significant reduction in rainfall. This period often sees a build-up of pollutants due to reduced atmospheric cleansing. The lack of rainfall means fewer opportunities for particulate matter to be washed out of the air. Furthermore, the increased use of biomass for cooking and heating during the cooler evenings of the dry season contributes to elevated levels of smoke and particulate matter. Temperature inversions, where a layer of warm air traps cooler air near the ground, are more frequent during the dry season, exacerbating pollution concentrations. The Harmattan wind, a dry and dusty trade wind blowing from the Sahara, frequently impacts Diourbel during this time, carrying fine dust particles that significantly degrade air quality. The wet season, from June to October, brings increased rainfall and higher humidity, generally leading to improved air quality as pollutants are removed through precipitation and increased vegetation uptake. However, intense rainfall events can also lead to temporary increases in fungal spores and mold, impacting respiratory health. Outdoor activities are generally more favorable during the wet season, particularly in July and August. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during the dry season, limiting prolonged outdoor exposure and taking precautions against dust inhalation. The transition periods between seasons can be particularly challenging, with fluctuating wind patterns and variable rainfall.