BackgroundPopulations in coastal cities are exposed to increasing risk of flooding, resulting in rising damages to health and assets. Adaptation measures, such as early warning systems for floods (EWSFs), have the potential to reduce the risk and impact of flood events when tailored to reflect the local social-ecological context and needs. Community perceptions and experiences play a critical role in risk management, since perceptions influence people’s behaviors in response to EWSFs and other interventions.MethodsWe investigated community perceptions and responses in flood-prone periurban areas in the coastal city of Machala, Ecuador. Focus groups (n = 11) were held with community members (n = 65 people) to assess perceptions of flood exposure, sensitivity, adaptive capacity, and current alert systems. Discussions were audio recorded, transcribed, and coded by topic. Participatory maps were field validated, georeferenced, and digitized using GIS software. Qualitative data were triangulated with historical government information on rainfall, flood events, population demographics, and disease outbreaks.ResultsFlooding was associated with seasonal rainfall, El Niño events, high ocean tides, blocked drainage areas, overflowing canals, collapsed sewer systems, and low local elevation. Participatory maps revealed spatial heterogeneity in perceived flood risk across the community. Ten areas of special concern were mapped, including places with strong currents during floods, low elevation areas with schools and homes, and other places that accumulate stagnant water. Sensitive populations included children, the elderly, physically handicapped people, low-income families, and recent migrants. Flood impacts included damages to property and infrastructure, power outages, and the economic cost of rebuilding/repairs. Health impacts included outbreaks of infectious diseases, skin infections, snakebite, and injury/drowning. Adaptive capacity was weakest during the preparation and recovery stages of flooding. Participants perceived that their capacity to take action was limited by a lack of social organization, political engagement, and financial capital. People perceived that flood forecasts were too general, and instead relied on alerts via social media.ConclusionsThis study highlights the challenges and opportunities for climate change adaptation in coastal cities. Areas of special concern provide clear local policy targets. The participatory approach presented here (1) provides important context to shape local policy and interventions in Ecuador, complimenting data gathered through standard flood reports, (2) provides a voice for marginalized communities and a mechanism to raise local awareness, and (3) provides a research framework that can be adapted to other resource-limited coastal communities at risk of flooding.

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Background: Populations in coastal cities are exposed to increasing risk of flooding, resulting in rising damages to health and assets. Local adaptation measures, such as early warning systems for floods (EWSFs), are urgently needed to reduce the risk and impact of flood events. The aim of this study was to assess community perceptions and self-reported actions in response to flooding in a tropical coastal city to inform flood risk reduction policies and programs.Methods: This qualitative case study was conducted in flood-prone areas in Machala, Ecuador, a coastal city exposed to seasonal floods and extreme floods during El Niño events. Adult community members from three periurban sites were invited to participate. Focus groups discussions (11 focus groups in total) were held with community members (n=65 people) from September to November 2014 to assess perceptions of flood exposure, sensitivity, adaptive capacity, and current alert systems. Focus groups discussions were audio recorded, transcribed, and coded by topic; participatory maps were field validated, georeferenced, and digitized using GIS software. Results: Community members identified the presence of annual flooding during the rainy season, as well as greater than normal flood events (depths ranging from 0.5 to 3 meters), which recurred every 3-4 years in some communities. The deepest floods occurred during the 1982 and 1997/1998 El Niño events. Community members perceived that exposure to flooding depended on the rainfall coinciding with high ocean tides, and geographic proximity to blocked drainage areas, canals, and low local elevation. Participants reported that children were the most sensitive group due to increased susceptibility to skin infections and mosquito borne diseases (i.e., dengue fever). Other sensitive groups included the elderly, physically handicapped people, low-income families, and recent migrants. They identified persistent social-ecological vulnerabilities that increased flood risk and exposure in the urban periphery, such as inadequate access to garbage collection, homes settled in precarious low-lying geographies, economic barriers, lack of political access, and lack of social mobilization. In addition, communities expressed a lack of social capital (e.g. political voice), despite the existence of formalized community councils. Key neighborhood resources with respect to flooding included green areas, schools, nurseries, fire stations, health clinics, police stations, a retention wall (berm), and an emergency meeting place. Challenges for adaptive capacity existed primarily in actions related to the preparation and recovery stages of flooding. Despite the presence of an official flood warning system, community member relied on informal communication channels via social media. Conclusions: The flood vulnerability assessment framework and participatory research process utilized here can potentially inform studies in other flood-prone regions to guide the development of EWSFs and other climate change adaptation policies and actions.

<p>Understanding disaster risk is the first priority for action of the Sendai Framework for Disaster Risk Reduction (SFDRR) and is the essential information needed to guide disaster governance and achieve disaster risk reduction. Flooding is a natural hazard that causes the highest number of affected people due to disasters. In Ecuador from 1970 to 2019 flooding caused the highest amount of loss and damage to housing, and from 2016 to 2019 there were 1263 flood events reported. However, the differentiated impacts in flood exposed areas and what can be done to reduce risk and its impacts are still not well understood. In this research, we explored the different dimensions of flood risk, namely hazard, exposure, and vulnerability, and investigated the drivers of risk in different ecological regions of Ecuador. The assessment was conducted at the parish level, the smallest administrative scale, for three selected provinces of Bolivar, Los Ríos, and Napo, representing not only the country’s three main ecological regions but also commonly affected territories due to flooding. Using an automated flood detection procedure based on Sentinel-1 synthetic aperture radar data, flood hazard information was derived from flood frequency and flood depth for the years 2017, 2018, and 2019. The drivers of exposure and vulnerability were derived from scientific literature and further evaluated and complemented during a participatory workshop with over 50 local experts from the different regions. Centered on this exercise, an indicator library was created to inform the data selection from various sources and provides the basis for deriving a spatially explicit flood risk assessment using an indicator-based approach. Impact data are available to validate the risk assessment at the parish level and with this reveal key drivers of flood risk in different ecological regions of Ecuador. This information will provide the basis to derive targeted measures for disaster risk reduction.</p>