Urban Wetland Losses and Land-Use Conservation Challenges in Three Latin American Cities

Abstract

Wetlands are valuable and threatened ecosystems throughout the world. They are essential for the maintenance of life and ecological balance, in addition to providing a larger number of benefits to human societies. Wetlands reduce the risk of flooding by regulating the flow of water, being essential to reduce the impacts of climate change, especially along the coasts and coastal cities of the world. Urban growth poses a risk to wetlands in and around urban areas. In this work, we quantify the loss trends of wetlands in urban areas in three Latin American countries between the years 2002 and 2019. We selected as case studies the wetlands of Aconcagua in Chile, Ciénaga de Mallorquín in Colombia, and Pantanos de Villa in Peru. Through multitemporal analysis of Quickbird satellite imagery collections, we classify land covers at 2.5-m resolution and identify areas covered by wetland. We quantify the losses and gains of the wetland areas and the areas surrounding them. We found that the three wetlands analyzed lost area, confirming the worldwide trend of loss. The Ciénaga de Mallorquín wetland was the one that decreased the most due to coastal dynamics and urbanization. The Pantanos de Villa wetland reduced its area due to the increase in urban areas that grew filling the wetland under the pressure of informal settlements and beach condominiums. Lastly, the Aconcagua wetland was reduced due to the increase in grasslands together with the increase in bare soil, also affecting the beaches and dunes. In all three case studies, urban wetlands decreased due to urban growth. For this reason, we call attention to the urgency of improving urban planning to ensure the maintenance of these key ecosystems to ensure more sustainable and resilient cities, as proposed by Sustainable Development Goal 11.