Land use and land cover maps are a classification of the territory that allows users to understand how their environment and nature have developed. Both concepts are widely used, and their interchangeable use often leads to confusion. 

“Land uses” describe “those human activities that are closely related to the earth’s surface,” while “land covers” are “the vegetation or artificial constructions that cover the earth’s surface” (Anderson et al. 1961).

Common examples of land cover include agricultural crops, built-up areas (such as urban and industrial zones), bodies of water (such as streams, rivers, and lakes), and vegetation (such as forests, shrublands, or grasslands). Both land use and land cover are direct products of the ongoing interaction between biotic, abiotic, and anthropogenic processes, which work together to shape the landscape.

The map below shows the land cover of the region comprising the San Juan Bay Estuary basin, which was classified for the PRGAP (Puerto Rico Gap Analysis Project, 2008) project using Landsat TM images from the year 2000.

High-density urban developments predominate in the Estuary basin. For this reason, built-up areas dominate the region, occupying 56 percent of the territory. This type of land cover is followed by wetlands (19 percent) and grasslands and pastures (10 percent).

On the other hand, if we look at the distribution of land cover by municipality, we observe that in most (Bayamón, Carolina, Cataño, San Juan, Guaynabo, Toa Baja, and Trujillo Alto), with the exception of Canóvanas and Loíza, urban land cover predominates. In the specific cases of Canóvanas and Loíza, forest and wooded wetlands predominate, respectively.

The municipalities with the highest density of urban cover are Guaynabo (72%), San Juan (70%), and Trujillo Alto (68%). On the other hand, Canóvanas is 54 percent covered by forests.