Earth, Volume 3, Issue 2 (June 2022) – 12 articles

This study aims to assess urban heat islands and land cover types in relation to vulnerable populations. The city of Richmond, Virginia was selected as the study area using the Census Block Group as the geographic unit of analysis. Regression analysis was carried out to examine the impacts of land cover types on ambient temperatures, while correlation analysis was used to assess the relationship between ambient temperature and vulnerable populations. Lastly, multivariate clustering analysis was performed to identify areas vulnerable to urban heat in the city. Findings suggest that: (1) impervious surfaces lead to higher ambient temperatures, while tree coverage has a cooling effect on urban heat; (2) vulnerable populations, except for older adults, tend to live in areas with higher ambient temperatures; and (3) vulnerable populations are spatially clustered in specific locations in the city. This study concludes with recommendations of mitigation measures to reduce the adverse effect of urban heat islands by applying high-albedo materials to urban surfaces and expanding tree coverage and green space. Full article

Globally, urbanisation has been the most significant factor causing land use and land cover changes due to accelerated population growth and limited governmental regulation. Urban communities worldwide, particularly in Iraq, are on the frontline for dealing with threats associated with environmental degradation, climate change and social inequality. However, with respect to the effects of urbanization, most previous studies have overlooked ecological problems, and have disregarded strategic environmental assessment, which is an effective tool for ensuring sustainable development. This study aims to provide a comprehensive vulnerability assessment model for urban areas experiencing environmental degradation, rapid urbanisation and high population growth, to help formulate policies for urban communities and to support sustainable livelihoods in Iraq and other developing countries. The proposed model was developed by integrating three functions of fuzzy logic: the fuzzy analytic hierarchy process, fuzzy linear membership and fuzzy overlay gamma. Application of the model showed that 11 neighbourhoods in the study area, and more than 175,000 individuals, or 25% of the total population, were located in very high vulnerability regions. The proposed model offers a decision support system for allocating required financial resources and efficiently implementing mitigation processes for the most vulnerable urban areas. Full article

Excess phosphate (P) loading to surface waters increases productivity sometimes causing an imbalance leading to eutrophication and water quality degradation. Wastewater contains elevated concentrations of P and other contaminants that pose threats to environmental health. Onsite wastewater systems (OWS) are used in many rural areas, but most are not monitored for P removal effectiveness. The goal of this research was to gain a better understanding of the P treatment efficiency of OWS in a nutrient-sensitive watershed. Groundwater monitoring infrastructure, including networks of wells and piezometers, was installed at five sites with OWS in coastal North Carolina. Groundwater samples from the piezometers and wastewater samples from the septic tanks were collected and analyzed for phosphate and physicochemical parameters. Results suggest that significant reductions in P concentrations (79.7 to 99.1%) were occurring in the soil immediately beneath the drainfield trenches, but P concentrations in groundwater near the OWS and more than 35 downgradient were alike and significantly elevated relative to background concentrations. OWS in areas with sandy soils such as the Hoods Creek watershed may be sources of P to groundwater and surface water. Nutrient management policies in watersheds with sandy soils should include provisions for assessing and reducing P contributions from OWS to surface waters. Full article

Africa has been a hotspot for the development of food and bioenergy crop cultivation since the 2000s, leading to systematic challenges towards its ability to become a bioeconomy. To reduce land-use conflicts with food crop cultivation, marginal African drylands (MADs) are proposed for sustainable bioenergy cropping systems (BCSs). This study reviews the foremost socio-economic and environmental challenges for BCSs on MADs, and the development of key principles for minimizing adverse outcomes towards a sustainable bioeconomy. Socio-economic prosperity in Africa depends on several systematic solutions, and BCSs that are based on perennial bioenergy crops are promising strategies as they provide a renewable and sustainable energy source for rural areas. However, critical multidimensional challenges such as poverty, food security, gender equality, access to energy, and environmental impact must also be considered to ensure long-term sustainability. This review argues for more transparent land sales/usage (considering the agricultural work of women) and more perennial bioenergy crops. In this context, key principles were derived for a people-centered bottom-up approach that is considered fundamental to ensure the sustainable development of BCSs on MADs in the future. Full article

The current paper presents the monitoring of soil and nutrient losses through runoff as the result of the climate change. The experimental results were recorded on the standard plots for runoff and erosion control. The results of the studies carried out highlight that total nitrogen losses range from 0.05 kg/ha to 12.60 kg/ha, potassium displaced from the plots has values between 0.02 and 1.35 kg/ha, the humus associated with the eroded soil includes values between 0.51 and 176.5 kg/ha, phosphorus is recorded with maximum values of 0.39 kg/ha, the total iron losses have values between 3.14 and 431.16 g/ha, manganese has losses from 1.69 to 290.82 g/ha, copper losses range from 0.15 to 7.62 g/ha, and, regarding zinc, the values are within the limits of 0.25–57.22 g/ha. The maximum values of the displacement of fertilizing elements from the sloping agricultural lands, by means of liquid and solid leaks, are registered at the plots left as permanent black fields, the plots practically unprotected against the rain erosion. The experiments were performed at the Soil Erosion Research and Development Station “Mircea Moțoc”, Perieni/Staţiunea de Cercetare Dezvoltare pentru Combaterea Eroziunii Solului “Mircea Moţoc”, Perieni (SCDCES—MM, Perieni), Vaslui County, an institution strategically located in an area subject to erosion soil. Additionally, the paper envisages how the National Rural Development Programme (NRDP) and the Common Agricultural Policy (CAP) can be of use in this area by analysing past lessons and providing an overview of what was done. Full article

Land-use changes adversely may impact ecological entities and humans by affecting the water cycle, environmental changes, and energy balance at global and regional scales. Like many megaregions in fast emerging countries, Tamil Nadu, one of the largest states and most urbanized (49%) and industrial hubs in India, has experienced extensive landuse and landcover change (LULC). However, the extent and level of landscape changes associated with vegetation health, surface permeability, and Land Surface Temperature (LST) has not yet been quantified. In this study, we employed Random Forest (RF) classification on Landsat imageries from 2000 and 2020. We also computed vegetation health, soil moisture, and LST metrics for two decades from Landsat imageries to delineate the impact of landscape changes in Tamil Nadu using Google Earth Engine (GEE). The level of vegetation health and drought for 2020 was more accurately assessed by combining the Temperature Condition Index (TCI) and Vegetation Condition Index (VCI). A Soil moisture index was subsequently used to identify surface permeability. A 75% expansion in urban areas of Tamil Nadu was detected mainly towards the suburban periphery of major cities between 2000 and 2020. We observed an overall increase in the coverage of urban areas (built-up), while a decrease for vegetated (cropland and forest) areas was observed in Tamil Nadu between 2000 and 2020. The Soil-Adjusted Vegetation Index (SAVI) values showed an extensive decline in surface permeability and the LST values showed an overall increase (from a maximum of 41 °C to 43 °C) of surface temperature in Tamil Nadu’s major cities with the highest upsurge for urban built-up areas between 2000 and 2020. Major cities built-up and non-vegetation areas in Tamil Nadu were depicted as potential drought hotspots. Our results deliver significant metrics for surface permeability, vegetation condition, surface temperature, and drought monitoring and urges the regional planning authorities to address the current status and social-ecological impact of landscape changes and to preserve ecosystem services. Full article

Water and wastewater services are invaluable for communities. The aim of this article is to understand and explain the overall long-term development of water services in Finland in the wider PESTEL framework with policy implications for the future. The original megastudy was based on an extensive literature review. The article first covers the birth and development of urban and rural water systems in Finland. This is followed by analysing selected decisions with long-term impacts, institutional issues, discussion and lessons learnt, and conclusions. The development of water services in Finland has largely been based on trust. In socio-institutional factors, institutional diversity is fundamental. Gradual expansion of water supply and wastewater systems has brought technical, economic and social benefits in a country with quite a dispersed population. Efficient water pollution control in communities was implemented within two decades through developing technology and applying proper legislation and control. Continuous and dynamic development has been a key principle. Nature-based solutions include raw water source selection, treatment processes such as managed aquifer recharge, sites for final effluents disposal, and water related land use planning. Aging infrastructure is the most pressing future challenge in Finland and worldwide and will need new requirements and innovations. Full article

There is a vivid scientific debate on how climate change affects stability, resilience, and conflict dynamics of human societies. Environmental security and collapse theory are theoretical approaches that claim severe negative impacts of climatic disasters on political stability, allegedly through the vector of food insecurity. Yet there is a disconnect between this work and the rich body of knowledge on food insecurity and society. The literature is fairly unanimous that (a) drought does not necessarily lead to famines, since (b) famines have a political context that is often more important than other factors; in addition, (c) famines and the distribution of suffering reflect social hierarchies within afflicted societies, and (d) even large-scale famines do not necessarily cause collapse of a polity’s functioning, as (e) food systems are highly interconnected and complex. As an illustrative case, the paper offers a longitudinal study of Malawi. By combining environmental history and analysis of Malawi’s idiosyncratic (post-)colonial politics, it discusses the possible connections between droughts, food insecurity, and political crises in the African country. The single-case study represents a puzzle for adherents of the “collapse” theory but highlights the complex political ecology of food crises in vulnerable societies. This has implications for a formulation of climate justice claims beyond catastrophism. Full article

Tidal flats are widely recognized as sentinels of coastal environment change, and are also the guardians for beachfront communities. As a result of urban expansion, tidal flats have increasingly received environmental pressures and the surrounding ecosystem has been functionally downgraded. However, the existing studies could not provide an effective method to identify and quantify the interactions between urban areas and tidal flats, which is essential work particularly for the coastal preservations in the United States. Aiming at this environmental crisis, we proposed an approach which quantifies the change patterns from a spatiotemporal perspective. To justify the rationality and feasibility of this approach, this study selected three highly urbanized coastal counties in the southeastern United States as the study area. We analyzed the annual dynamics during 1985~2015, and the generated spatiotemporal regularities were used to identify and quantify the correlations between urban expansion and tidal flat dynamics. This study not only justified that the coastal urban expansion could considerably damage the environment of tidal flats, but also verified an effective approach to investigate the correlations between urban expansion and tidal flat loss on a large spatiotemporal scale. Full article

The non-interconnected islands of Greece can benefit from the comprehensive use of RES to avoid water droughts and ensure energy autonomy. The present paper analyzes an HRES with two possible operating scenarios. Both of them include a wind park of 27.5 MW capacity, an 1175 m³/day desalination plant, and a 490,000 m³/day water tank in Lemnos, Greece. Regarding the wind power, 70% is used in the HRES, while the rest is channeled directly to the grid. The main difference comes down to how the wind energy is stored, either in the form of hydraulic energy or in the form of hydrogen. The lifespan of the system is 25 years, such as the produced stochastic series of rainfall, temperature, and wind of the area. Through the comparison of the operating scenarios, the following results arise: (i) the water needs of the island are fully covered and the irrigation needs have a reliability of 66%, in both scenarios. (ii) Considering the energy needs, the pumping storage seems to be the most reliable solution. (iii) However, depending on the amount of wind energy surplus, the use of hydrogen could produce more energy than the hydroelectric plant. Full article

The implementation of the European Landscape Convention (ELC) at national and regional scales has brought with it the need to rethink landscape governance policies. In view of the disparity of possible methods for approaching landscape knowledge derived from the ELC, this article proposes the study of the three most ambitious landscape assessment methods developed in Spain at present. Specifically, those of Valencia, Galicia and Catalonia. Their study and comparative reading allow us to conclude that they have a similar structure imposed in part by the requirements of the Convention. Despite this, all three demonstrate a wide operational flexibility depending on the purpose of each one. As a derivative of the study, it is argued that a method seeking to fulfill both a sustainability and a public participation agenda would have to combine quantitative forms of socio-ecological assessment with a qualitative measurement of cultural appreciation of landscapes. Full article

The upper-ocean processes controlling the near-surface layer temperature in the western Gulf of Mexico (GOM) are examined by estimating the contributing terms in the heat equation based on a 54-year simulation of an eddy-resolving HYbrid Coordinate Ocean Model (HYCOM). An eddy-active region defined by large surface eddy kinetic energy, representing the Loop Current eddies (LCEs) primary trajectory region, is selected for analysis. Both observations and the simulation reveal that the mean net surface heat flux cools the northern GOM and warms the southern GOM. Mean horizontal heat advection contributes to an overall cooling in the eddy-active region. Mean vertical heat advection has a strong seasonal variability associated with the strong seasonal cycle of the mixed layer process: winters tend to have a strong downward heat advection in the eddy-active region and a strong upward heat advection in the rest of the western GOM, while summers tend to have a weak advective heat flux. The downwelling (upwelling) is primarily due to the dominant anticyclonic (cyclonic) wind stress curl. Mean eddy heat flux convergence contributes to the overall warming in the upper ocean of the western GOM. Diffusive flux is not small across the thermocline, and it is expected to have an insignificant influence on the near-surface temperature. Full article