Maritime Climate in the Canary Islands and its Implications for the Construction of Coastal Infrastructures

Islands are isolated systems that depend on maritime trade for their subsistence. Efficient, durable and structurally reliable port infrastructures are essential for the economic and social development of islands. However, not all port infrastructures are designed in the same way. They can vary, depending on whether they are built on continental land, built on non-volcanic islands or built on volcanic oceanic islands (such as the Canary Islands, Spain). The latter islands are the subject of this study due to their specific features, construction difficulties and the importance of sound maritime infrastructures. The maritime climate of an area consists of the wave and storm regimes that affect it and, from these, the coastal dynamics and coastal formations of that area can be studied. For this reason, historical data were collated on significant directional wave heights from 1958 to 2015 from several WANA-SIMAR points in the virtual buoy network of State Ports of Spain located near the Canary Islands. These data have been studied to obtain the maximum directional wave heights (Hs) at each point. With this analysis, we have obtained useful summary tables to calculate wave height by a graphic method that transforms the distribution function into a line drawn on probabilistic paper, using reduced variables. This enables adjustments to be made by linear regression and minimum square methods to facilitate planning and design of maritime infrastructures in a reliable way. Doi: 10.28991/CEJ-2022-08-01-02 Full Text: PD

Propiedades de las rocas volcánicas de Canarias (España) utilizadas como material de escollera

In the Canary Islands, there is a wide spectrum of volcanic rocks with different properties to be used in public works. The aim of this study is to analyse the physical-mechanical properties of all the volcanic rocks present in the Canary Island archipelago in order to determine their suitability for use in maritime construction works. The great variety of volcanic rocks present on the islands have been grouped into lithotypes based on similar geo-mechanical behaviour. The laboratory test results obtained for these lithotypes establish their suitability or not to be used as breakwater material in accordance with Spanish regulations.En el archipiélago canario existe un amplio espectro de rocas volcánicas con diferentes propiedades para ser utilizadas en obras públicas. El objetivo de este estudio es analizar las propiedades físico-mecánicas de todas las rocas volcánicas presentes en el archipiélago canario con el fin de determinar su idoneidad para ser utilizadas en obras de construcción marítima. La gran variedad de rocas volcánicas presentes en las islas, se han agrupado en litotipos basados en un comportamiento geomecánico similar. Los resultados de los ensayos de laboratorio obtenidos para estos litotipos establecen su idoneidad o no para ser utilizados como material de escollera de acuerdo con la normativa española

Evolución temporal de los diseños de grandes presas en Gran Canaria (Islas Canarias)

The usefulness of ensuring the irrigation of their lands, made the farmers ask the engineers to draw up projects for large dams on the island of Gran Canaria, and more than 300 walls were designed between 1862 and 1980: a figure more than sufficient to gauge the importance of what was built during the water battle (79 large dams on 1,558 km²). From the rationalism of the first decades, with some very daring projects in the 30’s, functional pragmatism was imposed in the 50’s. In the 60’s, Dam Surveillance noted a certain technical lag with the dams of peninsular Spain. Not only in design criteria, but also in terms of materials, means and construction techniques, which led to new designs of large dams and materials in the 1970s. Thus, in these lines we intend to sketch briefly, then, the temporal evolution of the design, with special attention to the expressive power of the innovative projects.La utilidad de asegurar el riego de sus terrenos hizo que los agricultores encargaran a los ingenieros redactar proyectos de grandes presas en la isla de Gran Canaria, llegándose a diseñar más de 300 muros entre 1862 y 1980, cifra ésta más que suficiente para calibrar la importancia de lo construido durante la batalla del agua (79 grandes presas en 1.558 km²). Del racionalismo de las primeras décadas, con algunos proyectos muy atrevidos en los años 30, se impuso luego el pragmatismo funcional en los 50. Vigilancia de Presas constató en los 60 cierto retraso técnico con las presas de la España peninsular. No sólo en criterios de diseño, sino también en lo que se refiere a los materiales, medios y técnicas constructivas, lo que derivó en nuevos diseños de grandes presas y materiales en los 70. De este modo, en estas líneas pretendemos dibujar someramente, pues, la evolución temporal de lo diseñado, con especial atención a la potencia expresiva de los proyectos innovadores

Excess of naturally occurring fluoride in groundwater discharge in Macaronesia: Brava Island, Cape Verde

A high concentration of fluoride in groundwater poses a risk to human health. One of the best-known problems related to excess fluoride in drinking water is dental fluorosis. The characteristic composition of volcanic rocks in oceanic islands tends to present high concentrations of fluoride in groundwater discharge in springs. This study investigates fluoride content in two springs (Encontro and Ferreiros) on the island of Brava (Cape Verde), with the objective of monitoring the operational control production and distribution of drinking water. Using a spectrophotometric method, the level of fluoride found in the water discharged from the Encontro spring was found to be in the range of 4.8 to 6.5 mg/L, whereas at the Ferreiros spring, it was 5.8 to 6.2 mg/L. These results are far above the threshold limit established in the decree No. 5 of 2017 of the Cape Verdean legislation, whose legal threshold value for fluoride is 1.5 mg/L, the same value established by the World Health Organization (WHO). Due to geological conditions and consequences for the health of the population, the water is not adequate for consumption without proper treatment.info:eu-repo/semantics/publishedVersio

INCAMP: Master's Degree In The Carbon Neutral Management of Sport Marinas.

INCAMP project is developing an International Master’s Degree in the Carbon Neutral Management of sport marinas. In this article we present a draft on the distribution of the Master, with main learning materials that will be taught. The content has been divided into paths, modules and subjects, as following: 6 Fundamental modules; 18 Subjects; Practical and a Dissertation. Subjects of the Master has been selected to give the appropriate knowledge to the future students interested in Carbon Neutral Management of sport marinas. INCAMP has been created to meet future skills needs and to enhance the opportunities for cooperation between Higher Education, Vocational Educational Training and Industry, providing opportunities for cooperation among stakeholders as well as the exchange and transfer of knowledge to increase know-how. Throughout the master, students will be taught to understand and investigate the major processes and change drivers which contribute to climate conditions in the earth system at different scales, among them, the understanding of the interdependencies between the grand cycles (water, carbon, nitrogen, phosphorus) in the Sport Marinas Management System. Furthermore, they will analyse the roles played by the biosphere in global and local environmental change: how is it affected by environmental change and how can changes in the biosphere affect global change? A macro-scale view of global biosphere function in Earth history and the global impact of humanity, putting contemporary environmental change into wider context. Human systems of knowledge, values, organization, technology, and behaviour will be examined in relation to environmental change in an evolutionary and social development context. What is the utility of viewing human societies as systems? How do the complexity, diversity, stratification, and resource management strategies of human societies shape their contributions and responses to critical environmental parameters and challenges? The module introduces relevant cognitive, social, economic, and human ecological concepts and theory to understand historical developments in social-ecological systems and address contemporary issues of sustainability and wellbeing in an increasingly populous and globalised society. Specifically, the students will investigate the role of energy systems in causing and mitigating climate change for carbon neutral management of sport marinas. Debates and major trends in the role of technologies, economics, human behaviour, social change and governance in avoiding dangerous anthropogenic climate change

Effects of the 2021 La Palma volcanic eruption on groundwater resources (part I): Hydraulic impacts

The 2021 volcanic eruption in the Cumbre Vieja mountain range on La Palma Island (Canary Islands, Spain) raised concerns regarding the potential impact on groundwater resources. This study is the first part of a series of papers investigating those impacts, and focuses on the hydraulic impacts of the eruption, while subsequent papers will explore the geochemical consequences. Three boreholes equipped with sensors to measure hydraulic head, temperature, and electrical conductivity of groundwater were installed near the volcano. Monitoring started during the eruption and continued a year after it. Statistical analysis were performed to assess the relationship between the measured variables and real-time seismic-amplitude measurements (RSAM). In addition, the possibility of groundwater vaporization due to magma emergence was assessed with a groundwater flow numerical modelling of the island. Correlation coefficients were computed to assess the linear relationship between groundwater parameters and seismic signals, observing a statistically significant association, and suggesting near-instantaneous variations in parameters such as groundwater levels and EC. Different response patterns of groundwater levels were observed in recharging areas in highlands compared to discharge areas, showing an opposite correlation direction. Deduction of natural trends from the linear regression models of head and RSAM two months after the eruption revealed a more predictable impact on the groundwater system, as the hydrogeological system adjusts to the volcanic activity and its effects on the aquifer. The hydrogeological simulation of the "magma pumping effect" suggested that groundwater extraction was possible, but the absence of an appropriate groundwater monitoring network made it impossible to determine the amount of water extracted from the aquifer. The uncertainty analysis showed values up to 2000 m3·day−1. These findings have important implications for understanding the negative impacts of volcanic eruptions on groundwater resources, highlighting the need for regular monitoring and assessment by hydrogeologists and water management professionals

Water footprint of the water cycle of Gran Canaria and Tenerife (Canary Islands, Spain)

When it comes to exploiting natural resources, islands have limitations due to the quantity of these resources and the potential for harm to the ecosystem if exploitation is not done in a sustainable manner. This article presents a study of the water footprint of the different drinking water collection facilities and wastewater treatment facilities in the Canary Islands, in order to determine the blue, green, and grey water footprints in each case. The results show high percentages of drinking water losses, which raises the blue water footprint of the Canary Islands archipelago. The grey water footprint was studied in terms of Biochemical Oxygen Demand (BOD5 ). The green water footprint was not considered because it is a dimension of the water footprint mainly calculated for agricultural crops. Of the facilities studied, the wells for extraction of drinking water from the aquifer and the distribution network have the largest blue water footprint for the years under study (2019 and 2020). Only the wastewater treatment plants have a gray water footprint in this study, with values between 79,000 and 108,000 m3 per year. As a general conclusion, the most important factor in reducing the water footprint of the water cycle in the Canary Islands is optimization of the water resource, improving existing infrastructures to minimize losses, and implementing a greater circular economy that reuses water on a regular basis. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.This research was funded by the European Union's Horizon 2020 research and innovation program under grant agreement 101037424, project ARSINOE (climate-resilient regions through systemic solutions and innovations). : The development of this study has been possible thanks to the government of the Canary Islands, through the project “Analysis of the carbon and water footprint of the three main economic activities in the Canary Islands: Tourism, Agriculture and Integrated Water Cycle”, under grant agreement N◦ 20160026

IMPACTO DEL CAMBIO CLIMÁTICO EN LOS RECURSOS HÍDRICOS DE ESPAÑA IMPACT OF CLIMATE CHANGE ON THE WATER RESOURCES OF SPAIN

To the current global climate change scenario, we must add the use of water by the main economic sectors in Spain. Mainly, agriculture and tourism (Spain received 83 million tourists in 2019) are the main water demanders in the country, so we have studied the current water situation of the peninsula and the islands of the country, to know their ability to meet the demand of these key sectors. In order to address this analysis, we began by reviewing the various international conventions that have addressed the problem of global warming, and then addressed the methodology of the water situation in Spain and its two archipelagos (Canary and Balearic Islands) and the challenges faced by these three territories in relation to obtaining water in a scenario of climate change. Spain and the Balearic archipelago enjoy a Mediterranean climate characterized by dry summers. It is precisely during the summer season that most tourism is received and a greater demand for water must be satisfied. In the Canary Islands, due to their geographical condition, we speak of a subtropical climate with abundant microclimates within the 8 islands that make up the archipelago. This situation favours different water situations, mainly betting on desalination in the islands closest to the African continent, and on groundwater in the most western islands. In all three territories, the struggle for sustainable water management in relation to the tourism sector is underway, as well as an increase in the use of reclaimed water in irrigation, due to the growing threat of water scarcity scenarios in southern Europe, with the risk that this poses to the tourism and agricultural model of life that is being developed in Spain

The genesis of an extremely acidic perched aquifer within roasted pyrite waste in a fully urbanized area (Zaragoza, Spain)

Contaminated groundwater is a serious problem in developed countries. The abandonment of industrial waste may lead to acid drainage affecting groundwater and severely impacting the environment and urban infrastructure. We examined the hydrogeology and hydrochemistry of an urban area in Almozara (Zaragoza, Spain); built over an old industrial zone, with pyrite roasting waste deposits, there were acid drainage problems in underground car parks. Drilling and piezometer construction, and groundwater samples revealed the existence of a perched aquifer within old sulfide mill tailings, where the building basements interrupted groundwater flow, leading to a water stagnation zone that reached extreme acidity values (pH < 2). A groundwater flow reactive transport model was developed using PHAST to reproduce flow and groundwater chemistry, in order to be used as a predictive tool for guiding remediation actions. The model reproduced the measured groundwater chemistry by simulating the kinetically controlled pyrite and portlandite dissolution. The model predicts that an extreme acidity front (pH < 2), coincident with the Fe (III) pyrite oxidation mechanism taking dominance, is propagating by 30 m/year if constant flow is assumed. The incomplete dissolution of residual pyrite (up to 18 % dissolved) predicted by the model indicates that the acid drainage is limited by the flow regime rather than sulfide availability. The installation of additional water collectors between the recharge source and the stagnation zone has been proposed, together with periodic pumping of the stagnation zone. The study findings are expected to serve as a useful background for the assessment of acid drainage in urban areas, since urbanization of old industrial land is rapidly increasing worldwide

Effects of the 2021 La Palma volcanic eruption on groundwater resources (part II): Hydrochemical impacts

Volcanic eruptions can have significant implications for the management and sustainability of water resources in volcanic islands. The recent 2021 eruption of the Tajogaite volcano in La Palma Island (Canary Islands, Spain) raised concerns regarding its potential impact on groundwater resources. This study is the second part of a series investigating the hydrogeochemical impacts of the eruption. The study involved conducting three groundwater sampling campaigns during the eruption and two after the eruption, six months and one year after the eruption ceased. A total of 15 monitored points, including piezometers, wells, water galleries, and main gully collector of the island, all relatively close (2–15 km) to the erupted volcano, were sampled for the analysis of major, minor, and trace elements, physiochemical parameters, which were measured on-site. Statistical analyses were performed to assess the differences in groundwater composition before, during, and after the eruption. To evaluate the differences in water quality compared to pre-eruption events, 33 additional historical groundwater samples provided by the local Water Authority were assessed, and 103 groundwater analysis results from the groundwater data base of the Spanish National Geological Survey (IGME) were considered. The results of the study showed low but statistically significant changes in pH, T, conductivity and groundwater composition, mainly related to the high increases in several trace element concentrations, such as Al, Cr, Fe, Mo, Ni, Sr, Th, Tl, V, Zn, Ba, Cd, Co, Cu, Pb and U, with increments in various orders of magnitude for several elements. This increase was found to be highly influenced by the sample distance to the volcano during the eruption stage. The significance of these findings lies in their usefulness to enhance our understanding of the effects of volcanic eruptions on groundwater quality resources and demonstrate their resilience to this hazardous phenomenon, which ultimately underscores their reliability