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Changes in shoreline positions along the Rio Grande do Sul coast, southern Brazil, are analyzed to determine the spatial and temporal variability of shoreline movements at a regional scale. Using a kinematic Differential Global Positioning System (DGPS) survey method, the 618-km long shoreline of Rio Grande do Sul has been mapped on five occasions between November 1997 and April 2002. These data show that the coastline responds differently to hydrodynamic and meteorological forcing along the three major coastal sectors. The observed differences occur especially in the magnitude of changes, in the time interval in which the shoreline returns to a previous position, and in the length scale of dominant shoreline changes. Here changes in shoreline position are examined with respect to grain size, shoreline orientation, storms, El Nino-Southern Oscillation (ENSO) events, and gradients of longshore sediment transport. Data analyses and modeling indicate that the alongshore variability in the patterns of shoreline change through time is closely related to shoreline orientation and the associated gradients of longshore sediment transport. Results indicate also that variability in wave energy and storminess influence seasonal changes, whereas ENSO events influence interannual changes. This study demonstrates the importance of understanding the drivers of shoreline change at a regional scale and has applications in studies concerned with coastal engineering and shoreline response to climate change.

Deforestation and overexploitation of mangrove forests are affecting the livelihoods of millions of families that rely on their ecosystem services. Understanding local perceptions about the status and threats to mangroves is therefore crucial in addressing this issue. This research aims to enhance understanding of how sociodemographic factors influence resource use and perceptions of environmental changes through a questionnaire survey (n = 592 households) in five locations in Lamu County, home to 62% of Kenya’s mangroves. The results highlight the variability of mangrove use, ecosystem service recognition, and perceptions and drivers of change across locations, which are influenced by sociodemographic factors such as gender, education, and occupation. Although 89% of respondents reported using mangrove products, only 56% were able to identify mangrove ecosystem services, with those without formal education being less likely to recognize them. Interestingly, 50% of respondents perceived an increase in mangrove cover, contrary to research showing mangrove loss in the area over the last decade. Results show that communities are diverse and perceptions vary between groups, suggesting that implementing uniform management measures may be incomplete or ineffective. Awareness campaigns and capacity-building efforts must be tailored to reduce misperceptions about the state of local resources and to address the specific needs and challenges faced by different groups. Recommendations made here are widely applicable to promote more inclusive and sustainable community engagement in the management of natural resources in developing countries worldwide.

Coastal dunes have a crucial role in offering the ecosystem service of natural coastal protection. This paper investigates the importance of dunes in providing the ecosystem service of natural coastal protection on the North Coast of the State of Rio Grande do Sul (RS) in southern Brazil. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST®) Coastal Vulnerability Model was used to quantify the relative susceptibility to coastal erosion and flooding within the study area. First, the model was run to assess the susceptibility to coastal hazards considering the presence of dunes. Then, the model was run again without the presence of dunes. By comparing the results of the two model simulations, it was possible to identify where dunes contribute to reducing coastal exposure, which indirectly reflects their role in providing the ecosystem service of natural coastal protection. There are two main dune fields in the study area, one in the northern coastal sector and one in the southern sector, respectively in the municipalities of Torres and Cidreira. The index of exposure values produced by the two model simulations were very similar for locations along the Torres coastline. In contrast, along the coast of Cidreira, results from the model simulation without dunes produced higher exposure values than the simulation with the presence of dunes, suggesting that the dunes have an important role in offering natural coastal protection. Dunes are a natural barrier against coastal erosion and flooding, but they are not the only factor influencing the ecosystem service of coastal protection. In Torres, for instance, the local topography and the wind patterns contribute to reducing local exposure. The greatest threat in this sector is the urban sprawl.