Environmental & Earth Sciences | Encyclopedia MDPI

Subject:

Sort:

Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)

Type:

All Topic Review Biography

Topic Review

Transcaucasia, also known as the South Caucasus, is a geographical region on the border of Eastern Europe and Western Asia, straddling the southern Caucasus Mountains. Transcaucasia roughly corresponds to modern Armenia, Georgia and Azerbaijan, and are sometimes collectivelly known as the Caucasian States. The total area of these countries measures about 186,100 square kilometres (71,850 square miles). Transcaucasia and Ciscaucasia (North Caucasus) together comprise the larger Caucasus geographical region that divides Eurasia.

3.7K
23 Nov 2022

Topic Review

The White Sea is a small shallow semi-closed sea in the North-West of Russia. It is strongly affected by induced tides, so the tidal motion dominates in the sea. Sea ice is seasonal and the water salinity is less than in the neighbouring Barents sea due to strong river discharge. In this entry, we focus on the sources of data on the Sea.

3.7K
21 Jan 2021

Topic Review

Influence of Technologies on Sustainable Tourism

This study’s objective is to provide an overview on literature state-of-the-art related to sustainable tourism and technological innovations, offering insights for further advancing this domain. We employ a bibliometric analysis and a comprehensive review of 139 articles, collected from Web of Science and Scopus databases, for the purpose of: (i) exploring and discussing the most relevant contributions in the publication network: (ii) highlighting key issues and emerging topics; (iii) uncovering open questions for the future. Our findings reveal contradictory views on the risks and benefits of technology adoption. Artificial intelligence, internet of things, circular economy, big data, augmented and virtual reality emerge as major trends. Five work streams are identified and described, leading to a broader perspective on how technology can shape the future of sustainable tourism. Relevant theoretical and managerial implications are derived. Finally, a research agenda is proposed as guidance for future studies addressing the outcomes of digital disruption on sustainable tourism.

3.7K
29 Nov 2021

Topic Review

Soil contamination with heavy metals and organic pollutants poses an environmental problem due to their persistence, bioaccumulation and toxicity. Soil washing is one of the most common remediation technologies for permanent removal of undesirable pollutants. The effectiveness of soil washing is affected by many factors such as soil geochemistry, pollutant characteristics, type and chemistry of washing agents, and processing conditions. A variety of washing agents have been tested in soil washing with their different effect on pollutant removal and on the overall quality of treated soil. Development of soil washing is based on searching for an inexpensive, readily-available and environmentally-friendly agents to remediate polluted soils. Despite the unquestionable effectiveness of soil washing, spent washing solutions are generated that need further treatment. This entry presents the principles and application of soil washing technology, as well as the examples of washing agents and methods for liquid waste treatment. Soil washing is an ex-situ technology, including physical and/or chemical processes that aim to effectively remove pollutants from soil.

3.7K
08 Sep 2020

Topic Review

Barcelona (/ˌbɑːrsəˈloʊnə/ BAR-sə-LOH-nə, Catalan: [bəɾsəˈlonə], Spanish: [baɾθeˈlona]) is a city in Spain . It is the capital and largest city of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within city limits, its urban area extends to numerous neighbouring municipalities within the Province of Barcelona and is home to around 4.8 million people, making it the sixth most populous urban area in the European Union after Paris, London, Madrid, the Ruhr area and Milan. It is one of the largest metropolises on the Mediterranean Sea, located on the coast between the mouths of the rivers Llobregat and Besòs, and bounded to the west by the Serra de Collserola mountain range, the tallest peak of which is 512 metres (1,680 feet) high. Founded as a Roman city, in the Middle Ages Barcelona became the capital of the County of Barcelona. After merging with the Kingdom of Aragon, Barcelona continued to be an important city in the Crown of Aragon as an economic and administrative centre of this Crown and the capital of the Principality of Catalonia. Barcelona has a rich cultural heritage and is today an important cultural centre and a major tourist destination. Particularly renowned are the architectural works of Antoni Gaudí and Lluís Domènech i Montaner, which have been designated UNESCO World Heritage Sites. The headquarters of the Union for the Mediterranean are located in Barcelona. The city is known for hosting the 1992 Summer Olympics as well as world-class conferences and expositions and also many international sport tournaments. Barcelona is one of the world's leading tourist, economic, trade fair and cultural centres, and its influence in commerce, education, entertainment, media, fashion, science, and the arts all contribute to its status as one of the world's major global cities. It is a major cultural and economic centre in southwestern Europe, 24th in the world (before Zürich, after Frankfurt) and a financial centre. In 2008 it was the fourth most economically powerful city by GDP in the European Union and 35th in the world with GDP amounting to €177 billion. In 2012 Barcelona had a GDP of $170 billion; and it was leading Spain in employment rate in that moment. In 2009 the city was ranked Europe's third and one of the world's most successful as a city brand. In the same year the city was ranked Europe's fourth best city for business and fastest improving European city, with growth improved by 17% per year, and the city has been experiencing strong and renewed growth for the past three years. Since 2011 Barcelona has been a leading smart city in Europe. Barcelona is a transport hub, with the Port of Barcelona being one of Europe's principal seaports and busiest European passenger port, an international airport, Barcelona–El Prat Airport, which handles over 40 million passengers per year, an extensive motorway network, and a high-speed rail line with a link to France and the rest of Europe.

3.7K
16 Nov 2022

Topic Review

Basalt (/bəˈsɔːlt, ˈbæsɒlt, -sɔːlt/) is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt. Basalt lava has a low viscosity, due to its low silica content, resulting in rapid lava flows that can spread over great areas before cooling and solidification. Flood basalt describes the formation in a series of lava basalt flows.

3.7K
09 Nov 2022

Topic Review

Water-Related Issues in Bhutan

Water for hydropower in Bhutan has been in focus as compared to that allocated for irrigation, industries, and environmental demand. The demand for water in Bhutan has also increased in the last decade due to population increase, changes in lifestyle, and economic advancements through tourism and hydropower projects.

3.6K
28 Apr 2021

Topic Review

Acid rain has an acidity that is higher than that of normal rainwater. Normal rainwater is not neutral (which would be pH 7) but slightly acidic (it has a pH < 5.5), because some of the carbon dioxide CO2 dissolved in the water is present as carbonic acid H2CO3. In acid rain, chemicals from pollution and natural causes such as volcanic eruptions and emissions from vegetation increase the acidity of the water to as low as pH 4.4 to 4 (as measured in the 1990s in various places). Such acidic rainwater is dangerous for people, vegetation, water bodies including the oceans and its inhabitants, buildings and soil. Since the pH scale is logarithmic, a change from 5.5 to 4.5 means a tenfold increase in acidity. The three main pollutants that cause acid rain are the nitric oxides NO and NO2 (summarized as NOx) and sulfur dioxide SO2. These substances react with water to nitric acid HNO3 and sulfuric acid H2SO4. In the 1980s, in nearly all of Northern Europe and in the Northern United States, suddenly and unexpectedly, whole forests began to die (this effect got to be known as forest dieback). German forests especially experienced severe damage: from 8% in 1982 it increased to 50% in 1984, and stayed as such till 1987. The damage occurred amongst various tree species. Researchers established connections of this damage to acid rain. The mandatory installment of sulfur filters in coal power plants and of catalytic converters in cars in various industrialized countries reduced air pollution with the chemicals related to the formation of acid rain, and, although the forests are still not in perfect shape (about 20% are heavily impaired) a complete death was prevented.

3.6K
15 Nov 2022

Topic Review

Deforestation and Global Warming

Deforestation is a primary contributor to climate change. Land use changes, especially in the form of deforestation, are the second largest anthropogenic source of atmospheric carbon dioxide emissions, after fossil fuel combustion. Greenhouse gases are emitted during combustion of forest biomass and decomposition of remaining plant material and soil carbon. Global models and national greenhouse gas inventories give similar results for deforestation emissions. Although deforestation and peatland degradation are only about 10% of global carbon dioxide emissions (As of 2019), growing forests are also a carbon sink with additional potential to mitigate the effects of climate change. Some of the effects of climate change, such as more wildfires, may increase deforestation. Deforestation comes in many forms: wildfire, agricultural clearcutting, livestock ranching, and logging for timber, among others. The vast majority of agricultural activity resulting in deforestation is subsidized by government tax revenue. Forests cover 31% of the land area on Earth and annually 75,700 square kilometers (18.7 million acres) of the forest is lost. Mass deforestation continues to threaten tropical forests, their biodiversity and the ecosystem services they provide. The main area of concern of deforestation is in tropical rain forests since they are home to the majority of the planet's biodiversity.

3.6K
29 Nov 2022

Topic Review

Artificial Island

An artificial island or man-made island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure, to those that support entire communities and cities. Early artificial islands included floating structures in still waters, or wooden or megalithic structures erected in shallow waters (e.g. crannógs and Nan Madol discussed below). In modern times artificial islands are usually formed by land reclamation, but some are formed by the incidental isolation of an existing piece of land during canal construction (e.g. Donauinsel, Ko Kret, and much of Door County), or flooding of valleys resulting in the tops of former knolls getting isolated by water (e.g. Barro Colorado Island). One of the world's largest artificial islands, René-Levasseur Island, was formed by the flooding of two adjacent reservoirs.

3.6K
11 Oct 2022

Page
of
271

Featured Entry Collections

>>

Featured Books

>>

Encyclopedia of Social Sciences

Encyclopedia of Social Sciences
Chief Editor:
Michael McAleer

Encyclopedia of COVID-19

Encyclopedia of COVID-19
Chief Editor:
Stephen Bustin

Encyclopedia of Fungi

Encyclopedia of Fungi
Chief Editor:
Luis V. Lopez-Llorca

Encyclopedia of Digital Society, Industry 5.0 and Smart City

Encyclopedia of Digital Society, Industry 5.0 and Smart City
Chief Editor:
Sandro Serpa

Video Production Service

Feedback

Top