Coastal Cities Research Articles

Understanding the evolution of cities through urban stocks: A comparative analysis of Andean and coastal urban areas in Peru

AbstractThe evolution of cities follows distinct patterns that connect to the cultural and socioeconomic aspects of their populations and can be understood by studying their urban stocks. This paper examines the evolution of construction materials stocks (MS) in the building sector in five urban areas in Peru. The study employed a bottom‐up methodology and focused on the city of Abancay in the Peruvian Andes, comparing it to the coastal cities of Chiclayo, Tacna, and San Isidro, as well as Lince. Additionally, regression models were employed to examine the influence of socioeconomic factors associated with urban stock. The research highlights a transition from residential building stock to distinct patterns of socioeconomic development, with urban population and economic growth emerging as pivotal drivers of material stock variation. Notably, large coastal cities like Chiclayo, Tacna, San Isidro, and Lince exhibit significantly higher concrete MS per capita, albeit with varying growth rates. In contrast, Abancay, with lower income levels, displays a higher per capita level of adobe MS, reflecting its historical connection to Peru's heartland. The correlation of urban stock components with the human development index (HDI) emphasizes the latter's significance in understanding the trends of the stocks of the different construction materials that constitute a city. By examining MS in various locations, unique Peruvian traits are unveiled, offering insights for urban development in the Global South. These findings provide valuable guidance for aligning urban stock growth and related environmental burdens with socioeconomic development, fostering sustainability, and promoting rational planning for economic growth.

Understanding Tsunami Evacuation via a Social Force Model While Considering Stress Levels Using Agent-Based Modelling

Given massive events, such as demonstrations in coastal cities exposed to tsunamigenic earthquakes, it is essential to explore pedestrian motion methods to help at-risk coastal communities and stakeholders understand the current issues they face to enhance disaster preparedness. This research targets SDG 11 Sustainable Cities and Communities. It strengthens resilience in coastal areas by implementing a social force model using a microscopic agent-based model to assess the impact of human behaviour on evacuation performance by introducing evacuation stress levels due to a tsunami triggered in central Chile. Two scenarios with two environments and three crowd sizes are implemented in NetLogo. In Scenario 1, pedestrians walk at a relaxed velocity. In Scenario 2, tsunami evacuation stress is incorporated, resulting in pedestrians walking at a running velocity, taking, on average, four times less time to evacuate. We explored more realistic settings by considering the internal susceptibility of each agent to spread tsunami evacuation stress among other evacuees. Results from Scenario 2 show that internal susceptibility effects almost double the mean evacuation time for 200 agents. Findings suggest a trade-off between realism and the minimization of evacuation time. This research is considered a first step toward including stress in tsunami evacuations for sustainable evacuation planning.

Building Urban Climate Resilience: Assessing Awareness, Perception, and Willingness regarding Nature-Based Solutions and Climate Change among Stakeholders in Iligan City, Philippines

Iligan City has been the heart of major industries in steel, cement, and hydropower and is one of the highly urbanized coastal cities in Mindanao, Philippines. Due to its geological state, environmental challenges like flooding, natural disasters, and environmental degradation have been experienced by the city. With the climate crisis, these risks are being magnified. Recently, nature-based solutions (NBS) have gained significant attention worldwide, viewed as a key solution to the consequences of climate change. Yet implementation of strategies and policies regarding NBS, especially in developing countries, has received poor attention. Hence, this study aims to assess the awareness and perceptions of stakeholders in Iligan City regarding climate change, NBS, and willingness to engage in actions involving NBS. Stakeholder mapping and surveys were conducted through purposive sampling. A total of 187 respondents were interviewed from different sectors (LGUs, NGOs, the private sector, and academia) in Iligan City. Results revealed significant differences in awareness and perceptions across the distinct socio-economic backgrounds of stakeholders, where respondents with higher education and income have greater levels of awareness, perception, and willingness. The study recommends future targeted approaches and increased campaigns for climate change and sustainable solutions such as integrating NBS in adaptation strategies and mitigation plans to foster multi-level stakeholder collaboration.

A quantitative priority-based approach using a multi-criteria decision-making model for sustainable coastal city development

AbstractThroughout history, water availability has been an essential factor in shaping the development, culture, transportation, economic activities, and access to food in cities. The socioeconomic and cultural development of a city or country with a coast depends on the active use of the coast and the impact of the coast on urban life. In this context, for the development of coastal cities, it is necessary to determine coastal city criteria and specify their strategies in line with these criteria in order to increase coastal qualities. This research determined Bursa, located northwest of Turkey, as the study area. However, factors such as the absence of a coastal plan for the city and the inability of the coast to integrate into urban life have weakened the coastal city’s qualities of it. For this reason, this study aims to define Bursa’s coastal city criteria and determine strategies to increase the coastal city quality. The coastal city criteria developed depending on the examples of coastal cities in the world were evaluated by surveying local people and experts. The results of these surveys were digitized according to their priorities using Analytical Hierarchical Process (AHP), one of the multi-criteria decision-making (MCDM) methods. The results of this study determined the highest priority criteria among the three main and nine sub-coastal city criteria in evaluating the coastal city in Bursa. This study proposes a numerical method that develops effective and sustainable coastal design and planning strategies for Turkey and underdeveloped countries.

Analysis of influencing factors of seawater intrusion in the Yangtze River Estuary and control for water supply security

Seawater intrusion poses a significant threat to the water supply of coastal cities both presently and in the future. It is crucial to identify the controllable factors influencing seawater intrusion, both natural and anthropogenic, in order to ensure water supply security. This study examined seawater intrusion characteristics using monitoring data from 1994 to 2019. Factors such as daily flow rate, duration of intrusion, water quality, and tidal level were analyzed to establish correlations and identify the primary influencing factors in the Yangtze River Estuary. The findings reveal that seawater intrusion in this area is most prevalent from November to April, peaking in February and March. The key controllable factors affecting chloride levels at the intake are the daily flow rate at Datong Station and the tidal range at Xuliujing Station. Additionally, the study proposes control methods to safeguard water supply, including providing daily flow rate values for flushing seawater intrusion at Datong Station under different tidal ranges and intrusion durations. These research results provide valuable guidance for the emergency operation of the Three Gorges-centered reservoir group against seawater intrusion.

Forecasting municipal solid plastic waste generation and management policy using system dynamics: a case study of Khulna City in Bangladesh.

A comprehensive analysis of municipal solid plastic waste (MSPW) management while emphasizing plastic pollution severity in coastal cities around the world is mandatory to alleviate the augmenting plastic waste footprint in nature. Thus, decision-makers' persuasion for numerous management solutions of MSPW flow-control can be met through meditative systematic strategies at the regional level. To forecast solutions focused on systematic policies, an agent-based system dynamics (ASD) model has been developed and simulated from 2023 to 2040 while considering significant knit parameters for MSPW management of Khulna City in Bangladesh. Baseline simulation results show that per-capita plastic waste generation will increase to 11.6kg by 2040 from 8.92kg in 2023. Eventually, the landfilled quantity of plastic waste has accumulated to 70,000 tons within 18years. Moreover, the riverine discharge has increased to 834 tons in 2040 from a baseline quantity of 512 tons in 2023. So the plastic waste footprint index (PWFI) value rises to 24 by 2040. Furthermore, the absence of technological initiatives is responsible for the logarithmic rise of non-recyclable plastic waste to 1.35*1000=1350 tons. Finally, two consecutive policy scenarios with baseline factors such as controlled riverine discharge, increased collection and separation of plastic waste, expansion of recycle business, and locally achievable plastic conversion technologies have been simulated. Therefore, policy 2, with 69% conversion, 80% source separation, and 50% riverine discharge reduction of MSPW, has been found adequate from a sustainability perspective with the lowest PWFI ranges of 3.97 to 1.07 alongside a per-capita MSPW generation of 7.63 to 10kg from 2023 till 2040.

Assessment of reliable wave climate at jetty on open coasts: role of 2D spatio-temporal spectrum

Assessment of reliable wave climate at jetty on open coasts: role of 2D spatio-temporal spectrum

Mobility behaviors shift disparity in flood exposure in U.S. population groups

The current characterization of flood exposure is largely based on residential location of populations; however, location of residence only partially captures the extent to which populations are exposed to flood hazards. An important, yet under-recognized aspect of flood exposure is associated with human mobility patterns and population visitation to places located in flood prone areas. In this study, we analyzed large-scale, high-resolution location-intelligence data collected from anonymous mobile phone users to characterize human mobility patterns and the resulting flood exposure in coastal counties of the United States. We developed the metric of mobility-based exposure based on dwell time in places located in the 100-year floodplain. The results of examining the extent of mobility-based flood exposure across demographic groups reveal significant disparities across race, income, and education level groups. The results show that Black and Asian, economically disadvantaged, and undereducated populations in US coastal cities are disproportionally exposed to flood due to their daily mobility activities, indicating a pattern contrary to that of residential flood exposure. The results suggest that mobility behaviors play an important role in extending flood exposure reach disproportionally among different socio-demographic groups. The results highlight that urban flood risk assessments should not only focus on the level of flood exposure to residences, but also should consider mobility-based exposure to better learn the disparities in flood exposure among social groups. Mobility-based flood exposure provides a new perspective regarding the extent to which floods could disrupt people's life activities and enable a better characterization of disparity in populations' exposure to flood hazards beyond their place of residence. The findings of this study have important implications for urban planners, flood managers, and city officials in terms of accounting for mobility-based flood exposure in flood risk management plans and actions.

Liquefaction ground deformations and cascading coastal flood hazard in the 2023 Kahramanmaraş earthquake sequence

The 2023 Kahramanmaraş earthquake sequence produced extensive liquefaction-induced ground deformations and ongoing flooding along the shoreline of the Mediterranean port city of İskenderun, Türkiye. This study compiles field observations and analyses from cross-disciplinary perspectives to investigate whether earthquake-induced liquefaction was a significant factor for increasing the flood hazard in İskenderun. Geotechnical reconnaissance observations following the earthquakes included seaward lateral spreading, settlement beneath buildings, and failures of coastal infrastructure. Three presented lateral spreading case histories indicate consistent ground deformation patterns with areas of reclaimed land. Persistent scatterer interferometry (PSI) measurements from synthetic aperture radar (SAR) imagery identify a noticeably greater rate of pre- and post-earthquake subsidence within the İskenderun coastal and urban areas relative to the surrounding regions. The PSI measurements also indicate subsidence rates accelerated following the earthquakes and were typically highest near the observed liquefaction manifestations. These evaluations suggest that while the liquefaction of coastal reclaimed fill caused significant ground deformations in the shoreline area, ongoing subsidence of İskenderun and other factors likely also exacerbated the flood hazard. Insights from this work suggest the importance of evaluating multi-hazard liquefaction and flood consequences for enhancing the resilience of coastal cities.

Spatio-temporal pattern analysis of coastal zone in Nansha based on remote sensing technology

Among the most important and active areas of coastal cities is the coastal zone. Examining the changes in the coastal zone of Nansha District is helpful in identifying the spatiotemporal evolution pattern and driving force of this area, as well as serving as a guide for the preservation and exploitation of its resources. This is due to the fact that remote sensing's ability to collect and analyze coastlines can show minute variations in the way the water and land interact. The article uses drone orthophotos and Landsat and Quickbird paired with eight different sceneries from 1987 to 2021 to extract the coastline using remote sensing (RS) and geographic information system (GIS) techniques. The spatiotemporal features of the evolution of the Nansha shoreline are examined in order to guarantee correctness. and the motivating elements are talked about. The findings indicate that: 1) Over the previous 30 years, there has been a consistent upward tendency along Nansha District's shoreline. Among these, the percentage of artificial shoreline is growing annually, growing by about 56%, while the natural coastline is decreasing annually, decreasing by 70%. 2) There is a shift in the type of shoreline from natural to sea-reclamation, engineering construction, and aquaculture. 3) The modifications to the coastline have occurred in three phases: the first was the agricultural phase; the second was the port petrochemical phase; and the third was the reasonable restraint phase (quality construction). Wanqingsha, Longxue Island, and Nansha Bay's coastlines are all close to significant expansion areas of coastline. 4) The primary causes of the changes in the Nansha District shoreline are human activity, regional policy, and natural elements.

Identification of applicable regulation and public policy gaps regarding marine renewable energy in Mexico

Integrating renewables into the energy matrix enables efficient energy systems and meets the UN Sustainable Development Goals 7) affordable and clean energy, 9) industry, innovation, and infrastructure, 12) responsible production and use, and 13) climate action. A specific case is the use of marine renewable energy (MRE) for power supply in coastal cities affected by environmental and anthropogenic threats. MRE can be harnessed from waves, currents, offshore wind, and thermal and salinity gradients. In emerging economies, the marine renewable energy industry is at different stages from quantifying the potential, to device development, or testing. Currently, in Mexico, there is a wide range of marine energy projects despite the technological advances there is no framework for the device’s deployment.As a guide for developers, this article presents the current Mexican legislation on MRE. The review of the legislation has identified some niche opportunities that were highlighted during the research; legal pathway for planning and operational purposes.

3D visualization of hurricane storm surge impact on urban infrastructure

As climate change intensifies, resulting in more severe rainfall events, coastal cities globally are witnessing significant life and property losses. A growingly crucial component for flood prevention and relief are urban storm flood simulations, which aid in informed decision-making for emergency management. The vastness of data and the intricacies of 3D computations can make visualizing the urban flood effects on infrastructure daunting. This study offers a 3D visualization of the repercussions of hurricane storm surge flooding on Galveston, TX residences, illustrating the impact on each structure and road across varied storm conditions. We employ target detection to pinpoint house door locations, using door inundation as a metric to gauge potential flood damage. Within a GIS-based framework, we model the damage scope for residences exposed to varying storm intensities. Our research achieves three core goals: 1) Estimating the storm inundation levels on homes across different storm conditions; 2) Assessing first-floor elevations to categorize housing damages into three distinct groups; and 3) Through visualization, showcasing the efficacy of a proposed dike designed to shield Galveston Island from future storm surge and flood events.

In situ observations of rain rate and precipitation microphysics over the coastal area of South China: Perspectives for satellite validation

Abstract This study investigates precipitation observed by a set of collocated ground-based instruments in Zhuhai, a coastal city located at the southern tip of the Pearl River Delta of Guangdong Province in South China. Seven months of ground-based observations from a tipping-bucket rain gauge (RG), two laser disdrometers (PARSIVEL and PWS), and a vertically-pointing Doppler Micro Rain Radar-2 (MRR), spanning from December 2021 to July 2022, are statistically evaluated to provide a reliable reference for China’s spaceborne precipitation measurement mission. Rainfall measurement discrepancies are found between the instruments, though the collocated deployment mitigates uncertainties originating from spatial/temporal variabilities of precipitation. The RG underestimates hourly rain amounts at the observation site, opposite to previous studies, leading to 18.2% percent bias (Pbias) of hourly rain amounts when compared to the PARSIVEL. With the same measurement principle, the hourly-accumulated rain between the two laser disdrometers has a Pbias of 15.3%. Discrepancies between MRR and disdrometers are assumed to be due to different temporal/spatial resolution, instrument sensitivities and observation geometry, with a Pbias of mass-weighted mean diameter and normalized intercept parameter of gamma size distribution less than 9%. The vertical profiles of drop size distribution (DSD) derived from the MRR are further examined during extreme rainfalls in the East Asia monsoon season (May, June, and July). Attributed to the abundant moisture which favors the growth of raindrops, coalescence is identified as the predominant effective process and the raindrop mass-weighted mean diameter increases by 33.7% when falling from 2000 m to 600 m during the extreme precipitation event in May.

Potentially toxic elements in urban soils of the coastal city of the Sea of Azov: Levels, sources, pollution and risk assessment

Coastal cities are major centers of economic activity, which at the same time has negative consequences for the environment. The present study aimed to determine the concentrations and sources of PTEs in the urban soils of Taganrog, as well as to assess the ecological and human health risks. A total of 47 urban and 5 background topsoils samples were analyzed by ICP-MS and ICP-AES. A significant excess of Cu, Zn, and Sb was noted in urban soils compared to the upper continental crust and average world-soil (1.7–2.9 times). Statistical analysis showed that the elements in soils were of geogenic, mixed and anthropogenic origin. According to the single pollution index (PI), the greatest danger of soil pollution was represented by anthropogenic elements, namely Cu, W, Pb, Zn, Cd, and Sn, the levels of which were increased in residential and industrial areas. The median contents of As, Mn, Cr, Sr, Mo, Sb, Cu, W, Pb, and Zn were 1.1–2.1 times higher, while Cd and Sn were 2.5 folds higher in the urban soils compared to the background ones. The total pollution index (ZC) showed that only 15% of the soils had high level of pollution, which is typical for the industrial areas. Overall ecological risks were negligible or low in 92% of soils, and were mainly due to elevated levels of Cu, Zn, As, and Pb. Non-carcinogenic risks to humans were mainly related to exposure to La and Pb. The hazard index (HI) values for all PTEs were less than ten, indicating that overall non-carcinogenic risk for adults and children was low-to-moderate and, moderate, respectively. The total carcinogenic risk (TCR) exceeded threshold and corresponded to low risk, with Pb, As, and Co being the most important contributors. Thus, the industrial activities of Taganrog is the main source of priority pollutants.

Planning For Resilience: Examining Gaps in Cyclone Preparedness and Impacts on Marginalized Communities in India's East coast cities

Cyclones and associated storm surges pose a major threat to coastal communities in India, especially along the Bay of Bengal where their intensity is higher. This paper examines cyclone resilience planning in four coastal cities - Visakhapatnam, Puri, Rameshwaram, and Velankanni. A multi-dimensional analysis is undertaken to focus on disaster preparedness, tourism economy contributions, socio-economic inclusion, and sustainability principles. The key objective is to study the integration of cyclone resilience with equitable, tourism-based development to strengthen vulnerable communities through conceptual modeling. The research methodology employs a mixed methods approach combining literature review, secondary data analysis of resilience infrastructure and tourism statistics, and conceptual model development. Findings highlight continued infrastructure and preparedness gaps alongside persisting socio-economic disparities limiting resilience access for marginalized groups. While progress is visible on early warnings, shelters, and evacuations, constraints exist regarding storm-proofing of amenities, customized enterprise support, secure housing, and risk financing tools. The study concludes that resilient, sustainable outcomes require planning processes that engage tourism-dependent communities through bottom-up participation. Coupled with hazard-resilient land use standards, customized livelihood protection schemes, resilient affordable housing programs, and coherent governance; tourism-centric coastal cities can enhance capacities to absorb cyclone impacts and enable inclusive rebuilding. Key Words: Cyclone resilience, Coastal city planning, Socio-economic vulnerabilities, Tourism economies

Influences of daily solar radiation intensity on the sea-land breeze and pollutant dispersion in coastal areas

Solar radiation plays a crucial role in the formation of sea-land breeze (SLB) circulation in coastal areas, and the SLB circulation in turn influences the atmospheric diffusion of pollutants in coastal cities. Therefore, the characteristics of the SLB and its impacts on the pollutant distributions in Shanghai, China, are numerically investigated for three (low, medium, and high) daily solar radiation intensities (DSRIs). The results show that the pollutant dispersion is affected by both the horizontal flow of SLB circulation and the vertical thermal plume (TP). The SLB only transports pollutants within the near-ground layer, while TP removes pollutants from the boundary layer and then improves near-ground air quality. Both the intensities of the SLB and TP increase with the increase of DSRI, however, the relative strength of the two are different at different DSRIs. When the DSRI is high (28.35 MJ/m2/day) or low (9.45 MJ/m2/day) during the daytime, the sea breeze (SB) is much stronger than the TP, so the prevailing flow direction on the land is horizontal, causing large amounts of pollutants to be blown inland. For the medium DSRI (18.90 MJ/m2/day), the TP is more powerful in the early stage of the SB period, so the airflow across the land is dominated by the rising TP. Pollutants are mainly transported to the upper atmosphere and the best air quality can be achieved in the residential region. At night, the worst air quality occurs at low DSRI, because when the DSRI is low, the speed of the land breeze is also low and this decelerates the diffusion of pollutants to the sea by the wind.

Refined Sea Salt Markers for Coastal Cities Facilitating Quantification of Aerosol Aging and PM2.5 Apportionment.

Sea salt (ss) aerosols in PM2.5 are often quantified through source apportionment by applying sodium (Na+) and chloride (Cl-) as the markers, but both markers can be substantially emitted from anthropogenic sources. In this study, we differentiate ss from nonss (nss) portions of Na+ and Cl- to better apportion PM2.5 in a coastal tropical urban environment. Size-resolved ionic profiles accounting for Cl- depletion of aged ss were applied to 162-day measurements during 2012 and 2018-2019. Results show that the nss (likely anthropogenic) portions, on average, account for 50-80% of total Na+ and Cl- in submicron aerosols (PM1). This corresponds to up to 2.5 μg/m3 of ss in submicron aerosols that can be ∼10 times overestimated if one attributes all Na+ and Cl- in PM1 to ss. Employing the newly speciated ss- and nss-portions of Na+ and Cl- to source apportionment of urban PM2.5 via positive matrix factorization uncovers a new source of transported anthropogenic emissions during the southwest monsoon, contributing to 12-15% of PM2.5. This increases anthropogenic PM2.5 by ≥19% and reduces ss-related PM2.5 by >30%. In addition to demonstrating Cl- depletion (aging) in submicron aerosols and quantifying ssNa+, nssNa+, ssCl-, as well as nssCl- therein, the refined PM2.5 apportionment resolves new insights on PM2.5 of anthropogenic origins in urban environments, useful to facilitate policy making.

ICEEMDAN-Informer-GWO: a hybrid model for accurate wind speed prediction.

Extensive research has been diligently conducted on wind energy technologies in response to pressing global environmental challenges and the growing demand for energy. Accurate wind speed predictions are crucial for the effective integration of large wind power systems. This study presents a novel and hybrid framework called ICEEMDAN-Informer-GWO, which combines three components to enhance the accuracy of wind speed predictions. The improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) component improves the decomposition of wind speed data, the Informer model provides computationally efficient wind speed predictions, and the grey wolf optimisation (GWO) algorithm optimises the parameters of the Informer model to achieve superior performance. Three different sets of wind speed prediction (WSP) models and wind farm data from Block Island, Gulf Coast, and Garden City are used to thoroughly assess the proposed hybrid framework. This evaluation focusses on WSP for three specific time horizons: 5minutes, 30minutes, and 1hour ahead. The results obtained from the three conducted experiments conclusively demonstrate that the proposed hybrid framework exhibits superior performance, leading to statistically significant improvements across all three time horizons.

Coastal Flood Induced Salinity Intrusion Risk Assessment Using a Spatial Multi-criteria Approach in the South-Western Bangladesh

AbstractBangladesh is extremely vulnerable to sea-level rise and other climate-induced extreme events, such as flooding, storm surge, and salinity intrusion. The south-western coastal region of Bangladesh is particularly vulnerable to salinity intrusion caused by cyclone induced storm surges and coastal floods. Salinity intrusion endanger land productivity by increasing both soil and surface water salinity. Detailed risk assessment using spatial mapping approach can contribute to mitigating the effects of salinity intrusion on natural capital and the environment. In this study, we established and evaluated a spatial multi-criteria approach for mapping the risk levels of areas to salinity intrusion impacts using field data and geospatial techniques at the local scale. We evaluated the viability of the proposed approach using Khulna District, a major coastal city and saline prone area in the south-western Bangladesh. We considered three risk components (i.e. vulnerability, exposure and hazard) with 16 relevant criteria for the study. For each criterion, an Analytical Hierarchy Process (AHP) was used to build and weight spatial raster map layers. Individual maps for each risk component were generated using a weighted sum technique, and lastly, a risk map was created by combining those. Our generated maps correctly identified relevant spatial dimensions as well as risk levels (i.e. very-high to very-low). The outcomes of our study suggest that the southern (east and west) parts of the study area are mostly susceptible to salinity intrusion due to higher storm surge impacts, lower elevation, and land use patterns than other parts. We validate our findings using a qualitative and quantitative approach. We believe that this novel approach would be useful to create risk maps that policymakers and relevant stakeholders could potentially use to evaluate risks posed by flood induced salinity intrusion in coastal regions of Bangladesh and elsewhere with similar geo-climatic context.

Quantifying the Impact of Sea Level on Coastal Cities using Bayesian optimized Monte Carlo Simulation model

Quantifying the Impact of Sea Level on Coastal Cities using Bayesian optimized Monte Carlo Simulation model