**2. Materials and Methods**

### *2.1. Presentation of the Port-au-Prince Agglomeration*

The study area represents a group of municipalities that constitute the Port-au-Prince district, namely Port-au-Prince, Delmas, Cité Soleil, Tabarre, Pétion-Ville, Carrefour, Kenscoff, and Gressier, and the municipalities attached to Port-au-Prince district (Croix des Bouquets and Léogane). The 10 municipalities examined by this study form the "Port-au-Prince agglomeration" and cover an acreage of 1755.63 km<sup>2</sup> in the western department of the Republic of Haiti, located between 18◦20–18◦50 north latitude and 72◦0–72◦50 west longitude (Table 1, Figure 1). The relief presents an altitudinal gradient that shifts from lowlying plains to a succession of mountains with peaks exceeding 2000 m [25,26]. According to Köppen's classification, the climate of the study area ranges from tropical savannah in the lowland areas (Aw) to tropical subhumid in the mountainous areas (Cwa), characterized by a total annual rainfall between 1047 mm and 2000 mm and mean annual temperatures between 20 and 26 ◦C [27]. The natural vegetation largely comprises mangrove forests, shrub savannahs, and stands of pine and hardwood [28]. The economic fabric in the urban zone of the Port-au-Prince agglomeration is dominated by the informal sector (small- and medium-sized enterprises), which accounts for more than two-thirds of GDP and almost 80% of employment [29]. In the surrounding rural zones, the main economic activities are agriculture, livestock, and wood exploitation [30]. The Port-au-Prince agglomeration concentrates the bulk of the country's economic potential, thus attracting large numbers of people from around the country in search of remunerative activities [8,21]. Due to the unprecedented pressure on space of this poorly educated population (the literacy rate in Haiti is 61%), the city limits were extended to the entire southern fringe of the Cul-de-Sac Plain and the foothills of Morne l'Hôpital [16,22]. As a result, there are many threats to the environment in the Port-au-Prince agglomeration, including destruction of vegetation, gully erosion, flooding, and pollution [20,29]



**Figure 1.** Geographical location of the municipalities of the Port-au-Prince district and attached municipalities in the western department of Haiti.
