First record of <Emphasis Type="Italic">Sinocorophium homoceratum</Emphasis> (Yu, 1938) (Crustacea,Amphipoda, Corophiidae) from Korea     

Ara Ko  Kwan Ha Park  Soo-Gun Jo 《Ocean Science Journal》2017,52(2):277-281

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Drinking quality assessment of some groundwater sources along the stretch of Jhelum River in Kashmir Himalaya   总被引：1，自引：0，他引：1  

Rifat Ara Wani  Bhat Mohd Skinder  Aasimah Tanveer  Bashir Ahmad Ganai 《Environmental Earth Sciences》2017,76(18):630

The physicochemical properties and major ion chemistry of the groundwater sources from alluvial aquifers along the stretch (60 km) of Jhelum River in Kashmir Himalaya were determined in order to identify hydro-geochemical processes and their suitability for drinking purposes. The data depicted that calcium and bicarbonates were dominating among the cations and anions. The results indicate the trend of cation dominance as Ca²⁺ > Na⁺ > Mg²⁺ > K⁺, whereas anion dominance was in the order of HCO₃ ^? > Cl^? > SO₄ ^2?. Ratio of calcium to magnesium indicated the dissolution of Ca²⁺ from CaCO₃, which results in an increased levels of Ca²⁺ in the groundwater. Interpretation of Piper Trilinear plot understands the various geochemical processes affecting the groundwater quality and shows groundwater was dominated by Ca–HCO₃ type. The pH was recorded in the slightly alkalinity range 7.2–7.8 and was showing positive correlation with HCO₃ ^?. The chloro-alkaline indices revealed 86% of the sources exchange by a type of base-exchange reactions, rest by cation–anion exchange. Gibbs diagram revealed groundwater sources fall in the category of rock dominance. The concentration of the nitrogen compounds was in the progression of NO₃–N > NH₄–N > NO₂–N, and the PO₄ ^? fluctuated from 0.12 to 0.22 mg/L. Moreover, corrosivity ratio indicated that water from the majority of sources (71%) is safe to supply using pipes without any corrosive effects, while 29% of sources are corrosive in nature and need non-corrosive pipes for transporting and lifting of groundwater. The results revealed, groundwater samples were within permissible limits as prescribed by International and National standards, for drinking purposes. The State government and NGO’s can show their interest in utilizing such water resources to overcome the shortage of drinking water in a sustainable way for the daily consumption of the people living in the vicinity of Jhelum River.  相似文献   

Aeromagnetic contributions to the study of the Paleozoic basement structure of Southern High Plateaus (Eastern Morocco)     

Jamila Abderbi  Driss Khattach  Jamila Kenafi 《Arabian Journal of Geosciences》2017,10(19):423

The observed aeromagnetic anomaly map of Southern High Plateaus provides general information about the magnetization variations that are associated with subsurface magnetic sources, but it does not bring clear information about all geological elements of the study area. In this work, we attempt, by analyzing these aeromagnetic data, to determine structures of Paleozoic basement that may indicate the presence of major deep-seated structures in this area. To better understand and outline the basement geological structures, two approaches have been performed. Such analysis includes application of a low-pass filtering and spectral analysis, which permits an enhanced visual interpretation of the magnetization sources and leads to a better knowledge of the geological structures especially basins or intrusive bodies. The results obtained show magnetic anomalies indicating geological features trending NE–SW. They also reveal two depths of magnetic sources in the area. The deeper sources range from 1074 to 4057 m and reflect the Paleozoic basement. However, the shallower sources range from 153 and 596 m reflecting magnetic sources shallower than the basement. The outcomes of this study suggest a new structure and will contribute to better understand the characteristics and organization of the basin as well as the improvement of the geological map of the area for hydrocarbon exploration.  相似文献   

Use of time-domain electromagnetic (TDEM) method to investigate seawater intrusion in the Lebna coastal aquifer of eastern Cap Bon,Tunisia     

Amira Ziadi  Najla Tlatli Hariga  Jamila Tarhouni 《Arabian Journal of Geosciences》2017,10(22):492

A multi-method geophysical survey, using time-domain electromagnetic (TDEM) fields, is conducted on the north-eastern coastal aquifer of Cap Bon, Tunisia. The aim of the study is to investigate the inland extent saltwater intrusion, to estimate the fresh-saltwater transition zone, and to characterize the lithologic spatial variability of the underground layers. Moreover, the TDEM is used to determine both fluid resistivity and bulk resistivity which are required to calculate the porosity by applying the Archie’s equation. The survey of TDEM profiles is carried out along the left and right overbanks of the Lebna river from the coast until the Lebna dam. The interpretation and the analysis of these profiles allow us to better identify the flux exchanges between the river and the underlying aquifer. On the basis of the 1D and 2D longitudinal and transversal resistivity profiles as well as the existing boreholes data and groundwater quality, it seems that the freshwater-saltwater interface is moving forward inland. Furthermore, electromagnetic results combined to the Archie’s law show that the porosity values are at the ranges of 12–36 and 5–31% for the Quaternary outcropping and Pliocene formation, respectively.  相似文献   

Comparative hydrology: analysis of a semiarid and a humid tropical watershed   总被引：1，自引：0，他引：1  

José Carlos de Araújo  Julio Iván González Piedra 《水文研究》2009,23(8):1169-1178

This paper analyses measured data from two small tropical watersheds: one in a semiarid (Aiuaba, Brazil, 12·0 km², 5 years of measurements) and another in a humid environment (Jaruco, Cuba, 43·5 km², 21 years of measurements). The watersheds are similar with respect to catchment area (tens of km²), potential evaporation (2·1–2·6 m year^?1), temperature (22–30 °C) and relief (mild hillslope steepness); but show considerable hydrological discrepancies: average precipitation in the humid watershed is two times higher; average river discharge (mm year^?1) is five times higher; and surface water availability (mm year^?1) is 14 times higher than in the semiarid watershed. Long‐term operation of hypothetical surface reservoirs in both basins is simulated. The analysis shows that 73% of the average river discharge are available (with 90% annual reliability) in the humid watershed, against only 28% in the semiarid. The main cause of this difference is the excess evaporation, which consumes 55% of the stored water in the semiarid reservoir, but only 12% in the humid one. The research concludes that: (1) although precipitation indicators are higher in the humid area, they are of the same order of magnitude as in the semiarid; and (2) fluvial‐regime and water‐availability variables are more than one order of magnitude higher in the humid basin, which shows a multiplication effect of these hydrological processes. Such major hydrological differences, despite the similarities between the two tropical watersheds, show the importance of further investigations in the field of comparative hydrology. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Inter-annual changes in fish communities of a tropical bay in southeastern Brazil: What can be inferred from anthropogenic activities?     

Francisco Gerson Araújo  Samara Macedo Pinto  Leonardo Mitrano Neves  Márcia Cristina Costa de Azevedo 《Marine pollution bulletin》2017,114(1):102-113

We assessed inter-annual changes in fish assemblages of a tropical bay which experienced a heavily industrialized process in the last decades. A highly significant difference in community structure among the bay zones, and a decrease in fish richness and abundance over time were found. Changes in fish richness and abundance between the two first (1987–1988 and 1993–1995) and the two latter time periods (1998–2001 and 2012–2013) were sharpest in the inner bay zone, the most impacted bay area, and in the middle zone, whereas the outer zone remained comparatively stable over time. These changes coincided with increased metal pollution (mainly, Zn and Cd) in the bay and with the enlargement of the Sepetiba Port. Spatial changes in the fish community structure among the bay zones were related to differences in salinity, transparency and depth with this latter variable acting as a buffer stabilizing temporal community changes.  相似文献   

The new CutSprof sampling tool and method for micromorphological and microfacies analyses of subsurface salt marsh sediments,Algarve, Portugal     

João Araújo-Gomes  Ana Ramos-Pereira 《Geo-Marine Letters》2015,35(1):69-75

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Characterizing a complex aquifer system using geophysics, hydrodynamics and geochemistry: A new distribution of Miocene aquifers in the Zéramdine and Mahdia–Jébéniana blocks (east-central Tunisia)     

Fethi Lachaal  Mourad Bdir  Jamila Tarhouni  Ayadi Ben Gacha  Christian Leduc 《Journal of African Earth Sciences》2011,60(4):222-236

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Temporal variability in physicochemical properties,phytoplankton standing crop and primary production for 7 years (2002–2008) in the neritic area of Sagami Bay,Japan     

Koichi Ara  Koh Yamaki  Keisuke Wada  Satoshi Fukuyama  Takeshi Okutsu  Sadao Nagasaka  Akihiro Shiomoto  Juro Hiromi 《Journal of Oceanography》2011,67(1):87-111

Seasonal and interannual variations in physicochemical properties (i.e., temperature, salinity, dissolved oxygen and dissolved inorganic nutrients), chlorophyll a (Chl-a), particulate carbon and nitrogen (PC and PN, respectively), and primary production were investigated in the neritic area of Sagami Bay, Kanagawa, Japan, from January 2002 to December 2008. These abiotic/biotic variables, except for NH₄ ⁺–N, repeated similar seasonal variations for all 7 years. On the basis of the analysis of data obtained on 167 sampling dates, depth-integrated primary production in this water can be easily estimated from Chl-a at the surface using the regression equations obtained in the present study. Intermittently high values of dissolved inorganic nutrients, Chl-a, PC, PN and primary productivity at the surface during the summer stratified period were induced by high freshwater discharge from the rivers after rainfalls and by the expansion of nutrient-rich Tokyo Bay Water. Temperature, salinity and dissolved inorganic nutrients showed drastic variations within a scale of a few days and/or weeks, and these variations were related to sea levels that represent the intrusion of the Kuroshio Water, Intermediate Oyashio Water or deep water from the continental slope. However, there was no consistent trend in the variations in Chl-a, PC, PN and primary production due to the complex effects of these waters.  相似文献   

Holocene climate and environmental changes inferred from sediment characteristics and diatom assemblages in a core from Hwajinpo Lagoon,Korea     

Ara Cho  Daekyo Cheong  Jin Cheul Kim  Dong-Yoon Yang  Jin-Young Lee  Kaoru Kashima  Kota Katsuki 《Journal of Paleolimnology》2018,60(4):553-570

Hwajinpo is the largest lagoon in Korea and is located along the east coast of the country. It possesses Holocene sediments that provide an important record of past climate change. We studied the evolution of Hwajinpo Lagoon using grain size data and diatom assemblages in an 11.0-m core (HJ02), which was obtained at the mouth of a small river that drains into the lagoon. Core chronology was established with accelerator mass spectrometry ¹⁴C dates and optically stimulated luminescence dates. Diatom assemblages and grain size analysis revealed that estuarine conditions in the inner lagoon area transitioned to an open embayment ca. 8 ka as a result of sea-level rise. Around 7.8 ka, the open bay became a semi-closed bay as a consequence of development of a sand barrier. After the bay was semi-closed, marine water inflow was increasingly restricted as the sand barrier developed, and the semi-closed bay became a completely enclosed, low-salinity, brackish lagoon around 6 ka. There was an erosional hiatus between 5.5 and 1.7 ka (7.0 m depth), likely caused by river flooding and a switch in the location of drainage along the delta. The lagoon became oligohaline around 1.6 ka, likely because of increasing precipitation associated with an intensified Asian summer monsoon. This increase in precipitation resulted in expansion of the sand bar by sediment inflow, driven by agricultural development in the area. About 1000 years ago, the diatom assemblage was similar to the modern assemblage, suggesting the lagoon’s current geomorphic conditions had been established.  相似文献