Innovative Uses of Wave Power: Environmental Management of the Port of Ensenada, Mexico

2002 ◽  
Vol 36 (4) ◽  
pp. 74-84 ◽  
Author(s):  
Steven Czitrom ◽  
Ismael Núñez ◽  
Isabel Ramírez
Keyword(s):  
Environmental Management ◽  
Numerical Model ◽  
Water Column ◽  
Human Activities ◽  
Wave Power ◽  
Past Century ◽  
The Past ◽  
National University ◽  
Restrictive Measures ◽  
Shed Light

Over the past century, the water and sediments of the port of Ensenada, México, have accumulated a lot of pollution from human activities. Although present day restrictive measures inhibit any further accumulation, the existing aggregation in the sediments is sufficient to maintain high levels of contamination throughout the port, despite the flushing action of the tides. A SIBEO (SIBEO is an acronym for the Spanish SIstema de Bombeo por Energía de Oleaje) wave-driven seawater pump recently developed at the National University of Mexico is proposed to inject clean and oxygen rich seawater from outside the port to promote flushing in the more stagnant sections of the harbour. Results from a numerical model of the port hydrodynamics shed light on why the tides cannot on their own adequately flush the system, and how the wave-driven seawater pump will help to promote ventilation. Over the next 4 years, a cluster of SIBEO pumps is proposed to be installed on the Ensenada breakwater to inject unpolluted seawater at various locations in the port. A programme will be carried out to study the effects on the water column and sediments, in this first full-scale application of the SIBEO.

The use of historical data and artifacts in geomorphology

2008 ◽  
Vol 32 (1) ◽  
pp. 3-29 ◽  
Author(s):  
Stanley W. Trimble
Keyword(s):  
Environmental Management ◽  
Historical Data ◽  
Historical Geography ◽  
Past Century ◽  
The Past ◽  
Geomorphological Processes ◽  
Induced Changes

Historical data and artifacts, as commonly used in historical geography, can provide powerful tools for dating geomorphological processes over the past century or more and applications can range from months to millennia. Investigations in geomorphology and environmental management can be greatly enhanced by the use of historical techniques. The approach is useful for tracing human-induced changes as well as for those occurring naturally. Several primary techniques are introduced in this essay.

Coastal dune mobility over the past century: A global review

2020 ◽  
Vol 44 (6) ◽  
pp. 814-836 ◽  
Author(s):  
Jinjuan Gao ◽  
David M Kennedy ◽  
Teresa M Konlechner
Keyword(s):  
Human Activities ◽  
Vegetation Cover ◽  
Dominant Role ◽  
Coastal Dunes ◽  
Mediterranean Area ◽  
Global Scale ◽  
Coastal Dune ◽  
Sediment Supply ◽  
Past Century ◽  
The Past

The mobility of coastal dunes is characterised by bio-geomorphological responses related to change in boundary conditions, particularly sediment supply, wind and vegetation cover, as well as human activities. There remains uncertainty regarding the relative importance of these drivers on dune mobility at a global scale. In this study, trends and dominant drivers of coastal dune mobility are synthesised through the literature review focusing on shifts in dune mobility over the last century (1870–2018). In total, 176 individual dunes, with 55 dunes from the Europe-Mediterranean area, 23 from Africa, 30 from North America, 23 from South America, 20 from Oceania and 23 from Asia, are reviewed in this work. The results show that there is a worldwide trend of dune stabilisation, with 93% (164 out of 176) of the reviewed sites showing a loss of bare sand area due to an increase in vegetation cover and urbanisation expansion. Multiple factors have contributed to the stabilisation process, including (a) land-use change such as the change of traditional farming practises, coastal urbanisation and tourism development; (b) dune stabilisation projects; (c) sediment decline caused by the riverine and coastal constructions; and (d) change in climate (i.e. the decrease in windiness, and the increase in temperature and rainfall) and storms. Our results suggest human intervention played a dominant role in altering dune mobility for most dunes during the past century, while climate and storms are also important drivers, especially for dune sites with limited human activities.

scholarly journals Human-Induced Enrichment of Potentially Toxic Elements in a Sediment Core of Lake Balkhash, the Largest Lake in Central Asia

2020 ◽  
Vol 12 (11) ◽  
pp. 4717 ◽  
Author(s):  
Kun Huang ◽  
Long Ma ◽  
Jilili Abuduwaili ◽  
Wen Liu ◽  
Gulnura Issanova ◽  
...  
Keyword(s):  
Central Asia ◽  
Sediment Core ◽  
Human Activities ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Dominant Factor ◽  
Past Century ◽  
The Past ◽  
Lake Balkhash ◽  
The Impact

Over the past century, the impacts of human activities on the natural environment have continued to increase. Historic evolution of the environment under anthropogenic influences is an important reference for sustainable social development. Based on the geochemical analyses of a short sediment core of 49 cm from Lake Balkhash, the largest lake in Central Asia, potential factors historically influencing geochemical variation were revealed, and influences of human activity on regional environmental change were reconstructed over the past 150 years. The results showed that the dominant factor inducing changes in potentially toxic elements (V, Cr, Co, Ni, Zn, Cu, Cd, and Pb) is the physical weathering of the terrestrial materials. The variation in Ca content was influenced by the formation of authigenic carbonate. Since 1930, potentially toxic elements (Cr, Co, Ni, Zn, Cu, Cd, and Pb) in the lake sediments have obviously been affected by human activities, but the impact of human activities has not exceeded that of natural terrestrial weathering. In particular, the enrichment factors (EFs) for Cd and Pb reached 1.5. The average ecological risks of Cd were higher than the criterion of 30, suggesting a moderate risk to the local ecosystem in recent years. Total risk indices indicated moderate potential ecological risk for the lake ecology. The results will provide support for the environmental protection and better management practices of the Lake Balkhash watershed.

scholarly journals The November 2017Mw5.5 Pohang earthquake: A possible case of induced seismicity in South Korea

Science ◽  
2018 ◽  
Vol 360 (6392) ◽  
pp. 1003-1006 ◽  
Author(s):  
F. Grigoli ◽  
S. Cesca ◽  
A. P. Rinaldi ◽  
A. Manconi ◽  
J. A. López-Comino ◽  
...  
Keyword(s):  
South Korea ◽  
Induced Seismicity ◽  
Geothermal System ◽  
Past Century ◽  
Enhanced Geothermal System ◽  
Causal Factors ◽  
Industrial Activities ◽  
The Past ◽  
The Moment ◽  
Shed Light

The moment magnitude (Mw) 5.5 earthquake that struck South Korea in November 2017 was one of the largest and most damaging events in that country over the past century. Its proximity to an enhanced geothermal system site, where high-pressure hydraulic injection had been performed during the previous 2 years, raises the possibility that this earthquake was anthropogenic. We have combined seismological and geodetic analyses to characterize the mainshock and its largest aftershocks, constrain the geometry of this seismic sequence, and shed light on its causal factors. According to our analysis, it seems plausible that the occurrence of this earthquake was influenced by the aforementioned industrial activities. Finally, we found that the earthquake transferred static stress to larger nearby faults, potentially increasing the seismic hazard in the area.

The *amn'tgap: The view from West Yorkshire

2009 ◽  
Vol 45 (2) ◽  
pp. 251-284 ◽  
Author(s):  
JUDITH M. BROADBENT
Keyword(s):  
Nineteenth Century ◽  
Standard English ◽  
Past Century ◽  
First Person ◽  
British English ◽  
Repair Strategy ◽  
The Past ◽  
The Creation ◽  
Shed Light ◽  
Negative Form

The absence ofI amn'tfor the first person singular present tense negative form is taken to indicate that there is a gap in the paradigm. Recent accounts take a morphosyntactic approach and phonology is largely ignored. Such accounts typically focus on contemporary forms of Standard English. This paper, in contrast, compares nineteenth-century and contemporary West Yorkshire (WY) aux+n'tforms and pursues a largely phonological solution. The paper sets out to demonstrate that WY has never had a *amn'tgap and that changes over the past century shed light on the *amn'tgap problem. Contemporary WY is known to exhibit a phenomenon called secondary contraction, wherebyshouldn't[ʃʊdʔ], for example, may be pronounced [ʃunʔ]. I argue that secondary contraction is responsible for the creation of homophones foramn'tandaren't: [aːnt]/[aːt]. I will consider the possibility that certain aux+n'tforms have become lexicalised and that this has triggered secondary contraction as a phonological repair strategy. With the analysis of WY data as a backdrop, the paper then pursues the possibility that lexicalisation may have occurred, at a much earlier date, in precursors of Standard British English (SBE). Indeed, it seems plausible that homophony foramn'tandaren'tmay have led to prescription against new realisations ofamn't. The paper will show that grammaticallyamn'thas evolved in exactly the same way as other auxn'tforms, and it is only commentators who have treated it differently. If this is so, the *amn'tgap in SBE is man-made rather than grammatical in nature.

scholarly journals Legal issues concerning mine closure and social responsibility on the West Rand

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Francois Durand ◽  
Mariette Liefferink ◽  
Elize S Van Eeden
Keyword(s):  
South Africa ◽  
Environmental Management ◽  
Multidisciplinary Approach ◽  
Past Century ◽  
The West ◽  
The Past ◽  
The Social ◽  
Petroleum Resources ◽  
Current Water ◽  
National Environmental

Mining and, especially, gold and uranium mining have played a major role in the economy, history, and demography of South Africa. The contribution of the mines to the economy of South Africa over the past century has been overvalued, while the social injustices and negative environmental impacts that accompanied mining have been underplayed or ignored by the mining houses and government. The environmental situation has worsened significantly over the past few years due to the abandonment and pending closure of most of these mines. A reluctance is perceived on the part of the mining companies, and even government, to take responsibility for the damage caused by pollution, ecological degradation, and impact on human health by mining. Instead, the current informal policy appears to take smaller companies to court on minor environmental injustices to, perhaps, impress the broader public, while one of the biggest environmental concerns is stylishly treated. The inability of government to address the damage by mines effectively is in conflict with the National Water Act, the National Environmental Management Act, the Mineral and Petroleum Resources Act, the National Nuclear Regulator Act, and the Constitution of South Africa. The authors propose a multidisciplinary approach to address water-related environmental injustices on the West Rand and Far West Rand. We also describe the application of the National Environmental Management Act of South Africa (Act No. 107 of 1998) in the Wonderfonteinspruit and Tweelopiespruit Catchments and the current water quality situation.

Spin reversal of the rattleback: theory and experiment

1988 ◽  
Vol 418 (1854) ◽  
pp. 165-197 ◽  
Keyword(s):  
Numerical Model ◽  
Numerical Models ◽  
Spin Model ◽  
The Body ◽  
Past Century ◽  
Spin Direction ◽  
The Past ◽  
Spin Reversal ◽  
Observed Behaviour ◽  
Theory And Experiment

The behaviour of a top known variously as the rattleback, celt or wobblestone is studied. When spun on a flat, smooth, horizontal surface, self-induced oscillations about a horizontal axis eventually consume the initial spin energy; once the spinning has ceased, the oscillations decay and the body spins in the opposite direction. Many rattlebacks seem to be spin biased, reversing spin direction only once and only if the initial spin has the proper sense; others reverse readily from either initial spin direction. Analysis and simulation papers appearing over the past century have attempted, respectively, to explain and qualitatively predict the top’s possible behaviours, and to reconcile observed behaviour with various numerical models. In this work, the two broad theories proposed to explain the spin bias, one which neglects slipping and dissipation and one which incorporates these effects, are critically investigated by several means. The validity of the no-slip assumption is questioned. A numerical model which allows for aerodynamic effects and dry friction due to spinning and slipping is developed. The complicated equations of the numerical model are simplified by analysing the transfer of energy between the spin and oscillations. A comprehensive explanation of the behaviour based on this simplified spin model and the realistic limits of the no-slip motion is proposed. Finally, the predictions of the ‘complete’ numerical model and the simplified model are compared with experimental data.

scholarly journals A 100-year record of climate change and human activities inferred from the geochemical composition of sediments in Chaiwopu Lake, arid northwest China

2016 ◽  
Author(s):  
Wen Liu ◽  
Jinglu Wu ◽  
Xiangliang Pan
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Chemical Weathering ◽  
Northwest China ◽  
Past Century ◽  
Surface Erosion ◽  
Geochemical Composition ◽  
The Past ◽  
Element Concentrations ◽  
Arid Northwest China

An 81-cm sediment core from Chaiwopu Lake in arid northwest China was analyzed for <sup>137</sup>Cs activity and concentrations of major and trace elements. We used these data to discriminate between the influence of climate change and human activities on the geochemical change of the lake sediments over the past century. Elements Al, K, Ba, Ti, V, Fe, Ni, Mn, Li, and Be were mainly from detrital. Ca, Sr, and Mg concentrations were controlled by chemical weathering processes. Na came mainly from salt precipitation caused by a decline in water level. Enrichment factors for Pb and P in recent deposits are large, indicating they were influenced by human activies. Geochemical conditions during the past century can be divided into three stages: i) From ca. 1900 to the1950s element concentrations varied widely and frequently. In general, concentrations of typical mobile elements Ca, Sr, and Mg stay relatively high whereas values for other elements remained relatively low. This was interpreted to reflect variable climate under conditions of weak surface erosion intensity. ii) From the 1950s to the early 2000s, element concentrations display less variability. The Al, K, Ba, Ti, P, Cr, V, Fe, Ni, Mn, Co, Cu, Li, Zn, Be, Pb, and Na contents were generally higher, whereas contents of Ca, Sr, and Mg were on average lower. This indicates that the regional environment was conducive to surface erosion. Enrichment of trace metals and major elements in the sediment reflects enhanced human activities. iii) In the last decade, Pb and P exhibited a great increase, possibly associated with the input from fossil fuel combustion, sewage discharge and non-point-source pollution in the watershed. The lake volume decreased substantially because of groundwater extraction for municipal water, which resulted in a marked increase in salinity and enhanced Na precipitation.

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