scholarly journals Earthquake-induced liquefaction in the coastal zone, Case of Martil city, Morocco

2021 ◽  
Vol 298 ◽  
pp. 01002
Author(s):  
Mohamed El Hilali ◽  
Youssef Timoulali ◽  
Taj Benyounes ◽  
Mohamed Ahniche ◽  
Rabie El Bardai ◽  
...  
Keyword(s):  
Coastal Zone ◽  
Amplification Factor ◽  
Sedimentary Basins ◽  
Vulnerability Index ◽  
Supporting Evidence ◽  
Liquefaction Potential ◽  
Liquefaction Assessment ◽  
First Time ◽  
Seismic Hazard Estimation ◽  
Microtremor Measurements

According to historical documents and Moroccan earthquakes catalogs, the coastal zone has suffered in the past from several earthquakes. Understanding how sedimentary basins respond to seismic-wave energy generated by earthquake events is a significant concern for seismic-hazard estimation and risk analysis. The main goal of this study is to determine the distribution of the natural frequency value (F), the amplification factor value (A), and the soil vulnerability index (Kg) were carried out as an indicator for liquefaction potential sites in the Martil city based on the microtremor measurements. Liquefaction assessment was done at 96 stations using the HVSR approach provided by Nakamura (1989). According to the analysis results, the predominant frequency values range from about 0.31 to 5.63 Hz, and the amplification factor values range from 3 to 15. Based on these parameters, the vulnerability index Kg is determined, which can be used as a parameter in calculating the liquefaction potential of an area. This study shows supporting evidence for the first time that the HVSR of microtremors can be an excellent alternative indicator for an area's potential for liquefaction.

Contribution to the flora of marine algae of the coastal zone of the northeastern part of the Sea of Okhotsk

2018 ◽  
Vol 52 (1) ◽  
pp. 63-73
Author(s):  
N. V. Evseeva
Keyword(s):  
Coastal Zone ◽  
Sea Of Okhotsk ◽  
Marine Algae ◽  
Herbarium Material ◽  
Northeastern Part ◽  
The Sea Of Okhotsk ◽  
The Family ◽  
First Time

The revision of the herbarium material, collected in the northern part of the Sea of Okhotsk in 1965–1966 and stored in VNIRO, allowed to expand the taxonomic list of macrophyte algae of the coastal zone of this area. The locations of discovery of 24 previously unmentioned species are described. Myrionema balticum, Ulvella repens, Syncoryne reinkei, Acrochaetium arcuatum were found in the Sea of Okhotsk for the first time. Most species new for the Sea of Okhotsk is represented by epiphytes of the family Ulvellaceae (Chlorophyta). The final taxonomic list of this region, including literature data, consists of 169 species.

Indicators of Land Degradation Vulnerability due to Anthropic Factors

2013 ◽  
pp. 1400-1413 ◽  
Author(s):  
V. Imbrenda ◽  
M. D’Emilio ◽  
M. Lanfredi ◽  
M. Ragosta ◽  
T. Simoniello
Keyword(s):  
Land Management ◽  
Land Degradation ◽  
Resource Availability ◽  
Census Data ◽  
Vulnerability Index ◽  
Decision Makers ◽  
Accurate Estimation ◽  
Spatial Characterization ◽  
Land Cover Data ◽  
First Time

Land degradation is one of the most impacting phenomena on natural resource availability, both in quantitative and qualitative terms. In order to provide efficient tools for territorial sustainable management in areas affected by land degradation, it is important to define suitable models and indicators able to identify exposed areas and their vulnerability level, so as to provide an effective support for decision makers in identifying intervention priorities and planning mitigation/adaptation strategies. This work is focused on the evaluation at high spatial detail of land degradation vulnerability due to anthropic factors, which is a crucial issue in areas devoted to farming practices. Vulnerability is evaluated by integrating a new indicator of the mechanization level the authors recently developed, with a set of census based indicators of land management. The new indicator is independent of census data being based on land cover data; thus, it can provide a better spatial characterization and a more frequent updating compared to commonly adopted indices that are evaluated at municipal scale. By analyzing data for the whole Southern Italy, such an indicator was integrated for the first time at full spatial resolution to obtain a final vulnerability index of land management. This comprehensive index enabled a more accurate estimation of the land degradation vulnerability due to anthropic factors allowing the discrimination of priority areas within the municipal areas.

Indicators of Land Degradation Vulnerability Due to Anthropic Factors

2013 ◽  
pp. 87-101 ◽  
Author(s):  
V. Imbrenda ◽  
M. D’Emilio ◽  
M. Lanfredi ◽  
M. Ragosta ◽  
T. Simoniello
Keyword(s):  
Land Management ◽  
Land Degradation ◽  
Resource Availability ◽  
Census Data ◽  
Vulnerability Index ◽  
Decision Makers ◽  
Accurate Estimation ◽  
Spatial Characterization ◽  
Land Cover Data ◽  
First Time

Land degradation is one of the most impacting phenomena on natural resource availability, both in quantitative and qualitative terms. In order to provide efficient tools for territorial sustainable management in areas affected by land degradation, it is important to define suitable models and indicators able to identify exposed areas and their vulnerability level, so as to provide an effective support for decision makers in identifying intervention priorities and planning mitigation/adaptation strategies. This work is focused on the evaluation at high spatial detail of land degradation vulnerability due to anthropic factors, which is a crucial issue in areas devoted to farming practices. Vulnerability is evaluated by integrating a new indicator of the mechanization level the authors recently developed, with a set of census based indicators of land management. The new indicator is independent of census data being based on land cover data; thus, it can provide a better spatial characterization and a more frequent updating compared to commonly adopted indices that are evaluated at municipal scale. By analyzing data for the whole Southern Italy, such an indicator was integrated for the first time at full spatial resolution to obtain a final vulnerability index of land management. This comprehensive index enabled a more accurate estimation of the land degradation vulnerability due to anthropic factors allowing the discrimination of priority areas within the municipal areas.

scholarly journals Swedish Weight Sounding: A prospective portable soil investigation tools for liquefaction assessment of residential houses in Indonesia

2020 ◽  
Vol 156 ◽  
pp. 02010
Author(s):  
Yusa Muhamad ◽  
Bowman Elisabeth T. ◽  
Nugroho S.A
Keyword(s):  
Indirect Method ◽  
Direct Method ◽  
Low Cost ◽  
Fine Sand ◽  
Good Prospect ◽  
Torque Measurement ◽  
Liquefaction Potential ◽  
Potential Index ◽  
National Disaster ◽  
Liquefaction Assessment

National Disaster Management Agency (BNPB) statistics show that the majority of earthquake affected buildings are residential houses, whereas in practice, soil investigation is rarely conducted for residential houses in Indonesia. This study is preliminary work on the prospective of Swedish Weight Sounding (SWST) for liquefaction assessment for residential houses. Material used is poorly graded sand. The number of half turns from SWST (NSW) per meter for very loose and loose clean fine sand ranges from 4 to 168 (equivalent to SPT 0-30). Liquefaction potential was assessed using an indirect method by converting NSW into equivalent NSPT and direct method. In general, the factor of safety obtained from the direct method is more conservative (thus giving lower liquefaction potential index) than the indirect method. Torque measured for material in this study ranged from 6-54 Nm, equivalent to a specific energy range from 7-70 N/mm2. Liquefaction assessment using SWST data with torque measurement also indicated the soil is liquefiable. SWST also may be able to detect sand ageing. In summary SWS has a good prospect as a highly portable and low cost investigation tool for liquefaction assessment of residential houses in Indonesia.

scholarly journals Effect of Population Density of Pseudomonas fluorescens on Production of 2,4-Diacetylphloroglucinol in the Rhizosphere of Wheat

1999 ◽  
Vol 89 (6) ◽  
pp. 470-475 ◽  
Author(s):  
Jos M. Raaijmakers ◽  
Robert F. Bonsall ◽  
David M. Weller
Keyword(s):  
Biological Control ◽  
Population Density ◽  
Supporting Evidence ◽  
Pseudomonas Spp ◽  
Fluorescent Pseudomonas ◽  
Naturally Occurring ◽  
Rhizosphere Population ◽  
First Time ◽  
Take All

The role of antibiotics in biological control of soilborne pathogens, and more generally in microbial antagonism in natural disease-suppressive soils, often has been questioned because of the indirect nature of the supporting evidence. In this study, a protocol for high pressure liquid chromatography/mass spectrometry is described that allowed specific identification and quantitation of the antibiotic 2,4-diacetylphloroglucinol (Phl) produced by naturally occurring fluorescent Pseudomonas spp. on roots of wheat grown in a soil suppressive to take-all of wheat. These results provide, for the first time, biochemical support for the conclusion of previous work that Phl-producing fluorescent Pseudomonas spp. are key components of the natural biological control that operates in take-all—suppressive soils in Washington State. This study also demonstrates that the total amount of Phl produced on roots of wheat by P. fluorescens strain Q2-87, at densities ranging from approximately 105 to 107 CFU/g of root, is proportional to its rhizosphere population density and that Phl production per population unit is a constant (0.62 ng/105 CFU). Thus, Phl production in the rhizosphere of wheat is strongly related to the ability of the introduced strain to colonize the roots.

On some Paleocene invertebrates from the Potrerillos Formation (Difunta Group), northeastern Mexico

1995 ◽  
Vol 69 (5) ◽  
pp. 862-869 ◽  
Author(s):  
Francisco J. Vega ◽  
Maria Del Carmen Perrilliat
Keyword(s):  
Tidal Flat ◽  
Sedimentary Basins ◽  
Depositional Environments ◽  
Northeastern Mexico ◽  
Potrerillos Formation ◽  
First Time

Three species of mollusks and one annelid are described from the Paleocene upper mudstone member of the Potrerillos Formation (La Popa Basin), and from the upper part of the Rancho Nuevo Formation (Parras Basin). The species described include a gastropod, a bivalve, a nautiloid and a serpulid worm, which are formally reported for first time as Paleocene fauna of the Difunta Group in northeastern Mexico. The nautiloid species provides the basis for correlation between the two sedimentary basins of the Difunta Group, as it is reported for Paleocene layers of the two formations studied. Shoreface and tidal-flat depositional environments are inferred for the Paleocene rocks of the Difunta Group.

scholarly journals Benthic Diatom Composition in Coastal Zone of Black Sea, Sasyk Reservoir (Ukraine)

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 458
Author(s):  
Olena P. Bilous ◽  
Agata Z. Wojtal ◽  
Natalia O. Ivanova ◽  
Petro M. Tsarenko ◽  
Olga V. Burova ◽  
...  
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
Ecological Status ◽  
Assessment Method ◽  
Benthic Diatoms ◽  
The Black Sea ◽  
Salinity Changes ◽  
The Status ◽  
Freshwater Reservoir ◽  
First Time

The Sasyk Reservoir is one of the largest seaside reservoirs in Ukraine, artificially maintained as a freshwater area including various floodplain areas. The Reservoir originated from an estuary to now being an almost freshwater reservoir. The diatoms (Bacillariophyta) in benthos were investigated for analyzing the coastal zone diversity of the Black Sea inside the borders of Ukraine. The indicated diatom composition was formed by 97 species (100 infraspecies taxa). Some rare marine and freshwater taxa were noted, as well as three species reported in Ukrainian territory for the first time (Navicula vandamii Schoeman et R.E.M. Archibald, Sellaphora difficillima (Hustedt) C.E. Wetzel, L. Ector et D.G. Mann, and Mastogloia laterostrata Hustedt). The bioindicative characteristics of the diatom composition testified to the freshwater condition of the reservoir. Changes to the salinity level of the Sasyk Reservoir were exposed due to the composition of benthic diatoms. The presence of mesohalobous species (7 taxa) acknowledges conditions that are typical for estuaries and mouths of rivers and reveals the salinity changes in the Sasyk Reservoir. Likewise, the prevailing number of oligohalobous diatoms (61 taxa) reveal presence of freshwater in the reservoir. The implementation of the Polish phytobenthos lake assessment method for the nearby Ukrainian Reservoir was conducted for the first time. The multimetric Diatom Index for lake values varied from 0.39 to 0.76, and revealed alterations in the status over the Sasyk sites, ranging from good, moderate, to poor. Thus, it may be concluded that the current ecological status relating to the composition of benthic diatoms of the reservoir located in the coastal zone of the Black Sea is evaluated as having a moderate status class with some exceptions.

Overview of the liquefaction assessment and seismic stability of Duncan Dam: Specialty session, 46th Annual Canadian Geotechnical Conference Saskatoon, Saskatchewan, September 27–29, 1993

1994 ◽  
Vol 31 (6) ◽  
pp. 918-918
Author(s):  
Alan S. Imrie
Keyword(s):  
Key Words ◽  
Deformation Behaviour ◽  
Seismic Stability ◽  
Dam Safety ◽  
Safety Study ◽  
Liquefaction Potential ◽  
Glacial Sediments ◽  
Current State ◽  
State Of Practice ◽  
Liquefaction Assessment

This overview introduces a series of six papers describing the approach taken in a recent dam safety study to evaluate the liquefaction potential and deformation behaviour for the current seismic setting of Duncan Dam. The dam was originally designed and built in the mid-1960s and is an embankment structure founded on a thick sequence of glacial sediments. The papers were initially presented by a team of B.C. Hydro and their consultants at a specialty session held at the 46th Annual Canadian Conference in Saskatoon in September 1993. The papers provide an excellent summary of the current state of practice in evaluating liquefaction and post-liquefaction behaviour. Key words : embankment, liquefaction, seismic, specialty session.

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