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Topic Review
17O in Hydrological Cycle
17O is the one of the naturally occurring stable isotopes of oxygen, and also it has the lowest abundance, 0.038%(). The distribution of isotopes in hydrological systems is controlled by isotope fractionation processes. Oxygen isotopes fractionate through mass-dependent isotopic fractionation, which includes kinetic processes, isotopic exchange reactions, and physicochemical phenomena (diffusion, condensation, and evaporation).
  • 1.7K
  • 03 Aug 2021
Topic Review
Groundwater–Surface Water Interaction
Groundwater and surface water, though thought to be different entities in the past, are connected throughout the different landforms of the world. The interaction between groundwater and surface water (GW–SW) is responsible for a phenomenon like contaminant transport, and understanding it helps to estimate the effects of climate change, land use on chemical behavior, and the nature of water. 
  • 1.7K
  • 18 Apr 2023
Topic Review
Rainfall Threshold
Sediment-related disaster is one of the most significant natural disasters, from the perspective of magnitude, damage and loss to human life and infrastructure, and disruption to socio-economic activities. The rainfall threshold is the condition or amount of rainfall that is likely to initiate sediment-related disasters, it is agreed that the rainfall threshold is the most significant tool to predict impending occurrences.
  • 1.7K
  • 26 Oct 2022
Topic Review
Cultural Values in Water Management and Governance
Water is a fundamental resource for ecological and economic imperatives across the globe, contributing to the sustenance of livelihoods, food production and energy generation. Despite its importance, water resources are increasingly under threat due to overexploitation, pollution, scarcity, depletion and issues of accessibility/affordability. In addition to these threats, competitive water uses and strong interdependencies across different productive sectors. As such, “water crises” have been repeatedly identified among the top five global risks since 2012, with the international community acknowledging that water crises are regularly a crisis of management and/or governance. Cultural values associated with water management revolve around anthropocentrism, whereas values associated with water governance revolve around concepts of provenance/places. Implementation of ToC/cultural values is limited in practical applications, and an example is provided on how to improve on that. It's suggested that a succinct theory of culture such as Schwartz’s cultural values be considered to be an alternative to capture a greater heterogeneity across the breadth of water governance/management-related and basin-specific contexts. 
  • 1.6K
  • 18 Mar 2022
Topic Review
California Current
The California Current is a Pacific Ocean current that moves southward along the western coast of North America, beginning off southern British Columbia and ending off southern Baja California Sur. It is considered an Eastern boundary current due to the influence of the North American coastline on its course. It is also one of five major coastal currents affiliated with strong upwelling zones, the others being the Humboldt Current, the Canary Current, the Benguela Current, and the Somali Current. The California Current is part of the North Pacific Gyre, a large swirling current that occupies the northern basin of the Pacific.
  • 1.6K
  • 08 Nov 2022
Topic Review
Water Resource Management
Water resource management is the activity of planning, developing, distributing and managing the optimum use of water resources. It is an aspect of water cycle management. Water is essential for our survival. The field of water resources management will have to continue to adapt to the current and future issues facing the allocation of water. With the growing uncertainties of global climate change and the long-term impacts of past management actions, this decision-making will be even more difficult. It is likely that ongoing climate change will lead to situations that have not been encountered. As a result, alternative management strategies, including participatory approaches and adaptive capacity are increasingly being used to strengthen water decision-making. Ideally, water resource management planning has regard to all the competing demands for water and seeks to allocate water on an equitable basis to satisfy all uses and demands. As with other resource management, this is rarely possible in practice so decision-makers must prioritise issues of sustainability, equity and factor optimisation (in that order!) to achieve acceptable outcomes. One of the biggest concerns for our water-based resources in the future is the sustainability of the current and future water resource allocation. As water becomes scarce, the importance of water management grows vastly—finding a balance between humans' needs and the essential step of water resources sustainability in the environment.
  • 1.6K
  • 03 Nov 2022
Topic Review
Submarine Canyon
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km, from canyon floor to canyon rim, as with the Great Bahama Canyon. Just as above-sea-level canyons serve as channels for the flow of water across land, submarine canyons serve as channels for the flow of turbidity currents across the seafloor. Turbidity currents are flows of dense, sediment laden waters that are supplied by rivers, or generated on the seabed by storms, submarine landslides, earthquakes, and other soil disturbances. Turbidity currents travel down slope at great speed (as much as 70 km/h), eroding the continental slope and finally depositing sediment onto the abyssal plain, where the particles settle out. About 3% of submarine canyons include shelf valleys that have cut transversely across continental shelves, and which begin with their upstream ends in alignment with and sometimes within the mouths of large rivers, such as the Congo River and the Hudson Canyon. About 28.5% of submarine canyons cut back into the edge of the continental shelf, whereas the majority (about 68.5%) of submarine canyons have not managed at all to cut significantly across their continental shelves, having their upstream beginnings or "heads" on the continental slope, below the edge of continental shelves. The formation of submarine canyons is believed to occur as the result of at least two main process: 1) erosion by turbidity current erosion; and 2) slumping and mass wasting of the continental slope. While at first glance, the erosion patterns of submarine canyons may appear to mimic those of river-canyons on land, due to the markedly different erosion processes that have been found to take place underwater at the soil/ water interface, several notably different erosion patterns have been observed in the formation of typical submarine canyons. Many canyons have been found at depths greater than 2 km below sea level. Some may extend seawards across continental shelves for hundreds of kilometres before reaching the abyssal plain. Ancient examples have been found in rocks dating back to the Neoproterozoic. Turbidites are deposited at the downstream mouths or ends of canyons, building an abyssal fan.
  • 1.6K
  • 09 Nov 2022
Topic Review Video
New Drip Irrigation Technologies in Upper Egypt
Saving fresh water is a big challenge for the next generation due to enhanced living standards and population growth. In addition, the expansion of agricultural and industrial activities is causing unmatched demands for fresh water supplies across Egypt. The Nile River is Egypt’s main water resource, representing 69.4% of the total water resources, while rainwater, torrential water and groundwater, as well as recycled agricultural and sanitary drainage water and desalinated seawater, are estimated at about 30.6%. Smart drip irrigation systems are in great demand, especially in Upper Egypt. SDG’s of the circular economy and the WEF nexus lead to full implementation of drip irrigation systems, achieving ~6.6 BM3/year of direct saving from fresh water and/or doubling the cultivated area. In addition to PV tubes and other utilities, renewable energy, e.g, photovoltaic panels, will posses an important role in low-energy driven drip irrigation systems, reducing fossil-uses, CO2 emissions and devolving more sustainable processes that are less dependent on conventional energy sources.
  • 1.5K
  • 01 Nov 2022
Topic Review
Gas Hydrate Technology
Innovating methods for treating industrial wastewater containing heavy metals frequently incorporate toxicity-reduction technologies to keep up with regulatory requirements. This research reviews the latest advances, benefits, opportunities and drawbacks of several heavy metal removal treatment systems for industrial wastewater in detail. The conventional physicochemical techniques used in heavy metal removal processes with their advantages and limitations are evaluated. A particular focus is given to innovative gas hydrate-based separation of heavy metals from industrial effluent with their comparison, advantages and limitations in the direction of commercialization as well as prospective remedies. Clathrate hydrate-based removal is a potential technology for the treatment of metal-contaminated wastewater. In this research, a complete assessment of the literature is addressed based on removal efficiency, enrichment factor and water recovery, utilizing the gas hydrate approach. It is shown that gas hydrate-based treatment technology may be the way of the future for water management purposes, as the industrial treated water may be utilized for process industries, watering, irrigation and be safe to drink. 
  • 1.5K
  • 15 Apr 2022
Topic Review
Water Scarcity
Water scarcity, defined as long-term water imbalances occurring when the level of water demand exceeds natural water availability and supply capacity, is expected to pose high risks to both societies and economies in the next decade.
  • 1.5K
  • 03 Feb 2022
Topic Review
Driving Forces behind Climate Change
Climate change occurs through a complex set of interactive driving forces. According to the Intergovernmental Panel on Climate Change sixth assessment report (AR6; https://wg1.ipcc.ch/index.php/ar6/sixth-assessment-report-ar6; Accessed on 5 November 2022), human activity is the main driving force of climate change, whereas others contend that natural factors are also main causes.
  • 1.5K
  • 06 Dec 2022
Topic Review
GeoAI in Integrated Hydrological and Fluvial Systems Modeling
Geospatial artificial intelligence (GeoAI) allows the harnessing of big and high-dimensional data to better understand the hydrological processes in a particular system. Specifically, GeoAI provides new data analytic tools to the entire data processing cycle, such as sensor data fusion, hydrological modeling, data assimilation, multi-objective scenario optimization, smart decision support, evaluation of climate change impact, construction of early warning systems, and geo-visualization. 
  • 1.4K
  • 22 Jul 2022
Topic Review
Stepwells as Sustainable Water Management Structures
Stepwells were one such effective water management technologies used in India. Stepwells were constructed based on their geographical and topographical suitability, which revealed socio-cultural behaviors and beliefs.
  • 1.3K
  • 28 Sep 2022
Topic Review
Plastic Food Packaging: Consumer Perspective
The use of plastics for packaging has some advantages, since they are flexible and inexpensive. However, most plastics are of single use, which, combined with low recycling or reuse ratios, contributes substantially to environmental pollution. This work is part of a project studying the habits of Portuguese citizens concerning plastic food packaging and focuses on aspects related to sustainability. The survey was carried out via an online questionnaire about sustainability, recycling, and knowledge of the effects of plastic materials or their residues on the environment. The results were obtained based on a statistical analysis of the data. The participants tend to think about the negative impact of plastic packages on the environment; 39% sometimes do not buy plastic; and 30% try to look for alternatives. A substantial fraction, 81%, support the avoidance of plastic utensils and reduction in the use of plastic bags. Most participants have a good knowledge of recycling and strongly agree with the use of recycled materials, and 87% of respondents practice separation of different types of waste for recycling. Changing plastic consumption habits has not been an easy task. Nevertheless, it is expected that society will increasingly move toward sustainable habits, questioning its actions and considering their impact on the environment.
  • 1.3K
  • 13 Sep 2021
Topic Review
Sand Dam Technology
Sand dam technology filters and protects water from contamination and evaporation with low to no maintenance cost. Sand dams improve the socio-economy of the community and help to cope with drought and climate change. However, success depends on the site selection, design, and construction. The ideal site for a sand dam is at a transition between mountains and plains, with no bend, intermediate slope, and impermeable riverbed in a catchment with a slope greater than 2°. The spillway dimensioning considers the flow velocity, sediment properties, and storage target, and the construction is in multi-stages. Recently, the failure of several sand dams because of incorrect siting, evaporation loss, and one-stage construction were reported. Revision of practitioners’ manuals by considering catchment scale hydrological and hydrogeological characteristics, spillway height, and sediment transport are recommended. Research shows that protected wells have better water quality than open wells and scoop holes. Therefore, the community should avoid open defecation, pit latrines, tethering of animals, and applying pesticides near the sand dam. 
  • 1.3K
  • 01 Jul 2021
Topic Review
Astrooceanography
Astrooceanography is the study of oceans outside planet Earth. Unlike other planetary sciences like astrobiology, astrochemistry and planetary geology, it only began after the discovery of underground oceans in Saturn's Titan and Jupiter's Ganymede. This field remains speculative until further missions reach the oceans beneath the rock or ice layer of the moons. There are many theories about oceans or even ocean worlds of celestial bodies in the Solar System, from oceans made of diamond in Neptune to a gigantic ocean of liquid hydrogen that may exist underneath Jupiter's surface. Early in their geologic histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, and a runaway greenhouse effect may have boiled away the global ocean of Venus. Compounds such as salts and ammonia dissolved in water lower its freezing point so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice. Unconfirmed oceans are speculated beneath the surface of many dwarf planets and natural satellites; notably, the ocean of the moon Europa is estimated to have over twice the water volume of Earth. The Solar System's giant planets are also thought to have liquid atmospheric layers of yet to be confirmed compositions. Oceans may also exist on exoplanets and exomoons, including surface oceans of liquid water within a circumstellar habitable zone. Ocean planets are a hypothetical type of planet with a surface completely covered with liquid. Astrooceanography is closely related to Astrobiology, as oceans are expected to have higher chances to house simple forms of life.
  • 1.3K
  • 01 Nov 2022
Topic Review
Probiotics for Freshwater Fish Farming
Probiotics for freshwater fish farming can be administered as single or multiple mixtures. The expected benefits of probiotics include disease prophylaxis, improved growth, and feed conversion parameters, such as the feed conversion rate (FCR) and specific growth rate (SGR).
  • 1.2K
  • 20 Dec 2021
Topic Review
Groundwater Level Modeling with Machine Learning
Groundwater is the largest global reservoir of liquid freshwater, which is under increasing stress due to overdraft. Groundwater is a vital source of freshwater, supporting the livelihood of over two billion people worldwide. The quantitative assessment of groundwater resources is critical for sustainable management of this strained resource, particularly as climate warming, population growth, and socioeconomic development further press the water resources. Rapid growth in the availability of a plethora of in-situ and remotely sensed data alongside advancements in data-driven methods and machine learning offer immense opportunities for an improved assessment of groundwater resources at the local to global levels.
  • 1.2K
  • 06 Apr 2022
Topic Review
Lemongrass Essential Oil
Cymbopogon spp. are fast-growing C4 perennial sedges from the grass family Poaceae and are primarily cultivated for their essential oils. The genus lemongrass comprises about 180 species, such as Cymbopogon citratus, Cymbopogon flexuosus, Cymbopogon winterianus, Cymbopogon martinii, Cymbopogon nardus, and Cymbopogon refractus. Lemongrass (Cymbopogonspp.) oil is a cocktail of various terpenes and terpenoids, out of which the major components belong to cyclic and acyclic monoterpenes. The monoterpenes are derived from geranyl diphosphate (GPP).
  • 1.2K
  • 29 Mar 2022
Topic Review
Health Impact of Drying Aral Sea: One Health
Once one of the largest saline lakes, the Aral Sea, was recognized as a significant environmental disaster as the water level decreased dramatically. Water level decrease increases water salinity, affecting biodiversity. Exposed lake beds become the source for fine dust picked up by the dust storms and spread across a long distance, affecting people’s health in surrounding areas. 
  • 1.2K
  • 13 Apr 2022
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