Urban development versus wetland loss in a coastal Latin American city: Lessons for sustainable land use planning

• Published in: Land use policy Vol. 80; pp. 47 - 56
• Main Authors: Rojas, Carolina, Munizaga, Juan, Rojas, Octavio, Martínez, Carolina, Pino, Joan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-01-2019; Elsevier Science Ltd
• Subjects: Aquatic ecosystems; Biodiversity; Classification; Coastal wetland; Coasts; Ecosystem services; Ecosystems; Environmental assessment; Environmental changes; Environmental regulations; Flood control; Flood management; Flooding; Floods; Hazard mitigation; Image classification; Land cover; Land use; Land use change; Land use management; Land use planning; Landsat; Landsat satellites; Leisure; Metropolitan area; Metropolitan areas; Mitigation; Nature conservation; Preservation; Purification; Recreation; Regulation; Remote sensing; Satellite imagery; SEA; Services; Sustainable use; Tsunamis; Urban areas; Urban development; Urban growth; Urban planning; Urban sprawl; Urbanization; Water purification; Water treatment; Wetlands; Chile; Flooding; Metropolitan area; Urban planning; Coastal wetland; Land use change; SEA
• ISSN: 0264-8377; 1873-5754
• DOI: 10.1016/j.landusepol.2018.09.036

•Coastal wetlands provide ecosystem services to urban areas (e.g. tsunami flood mitigation). Despite this, they are threatened by urbanization.•Recent (2004–2014) wetland loss by urbanization in the Concepción Metropolitan Area (Chile) has been assessed using remote sensing.•Potential effects of Metropolitan Urban Plan (MUPC) on wetland have been inferred by applying the Strategic Environmental Assessment.•Urban growth is expected to continue despite wetland protection stated in the MUPC, thus affecting the provision of flooding mitigation.•SEA provides a useful tool to prevent the negative effects of urban plans and help to mitigate them, especially in the early stages of development.
Urbanization is a primary cause of wetland loss in coastal metropolitan regions. Therefore, it challenges the preservation of biodiversity and the provision of key ecosystem services for urban settlements. These services include leisure and recreation, climate and water regulation, water purification, and especially alleviation of natural hazards. Tsunami flood mitigation is a particularly valuable regulating service provided by these wetlands, as recently evidenced during the 2010 tsunami that hit the central coast of Chile.
The Concepción Metropolitan Area (CMA), located on the central coast of Chile, has experienced noticeable wetland loss in recent decades. Our study focused on the Rocuant-Andalién wetland, which has been particularly affected by urbanization. This wetland strongly contributes to flood control, and has provided effective protection against the CMA’s latest tsunamis (1835 and 2010). Based on Strategic Environmental Assessment (SEA), we have quantified urban growth over the wetland, both executed and projected under the Metropolitan Urban Plan of Concepción (MUPC). Recent loss in wetland area by urban growth has been quantified using land use and cover change (LUCC) maps from 2004 to 2014, obtained from the classification of Landsat images. Prospective changes (considering the complete MUPC deployment) have been inferred by combining the MUPC with the 2014 land cover map. In addition, we quantified the observed effect and planned urban growth on the wetland protected area, geoforms and potential flooding based on the area affected by the last Tsunami. Results show that urban areas have increased by 28% between 2004 and 2014, while future increase is expected to reach 238%. In contrast, wetland area has decreased by 10% from 2004 to 2014 and is expected to decrease by up to 32 %. Thus, the MUPC is not contributing to the mitigation of wetland loss nor the preservation of its biodiversity and ecosystem services. Implications for coastal planning are discussed.