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1.
Alluvial fans and shallow carbonate lakes interfered in the Teruel half‐graben during the Late Miocene–Pliocene. Tectonic influence is recorded in alluvial and lacustrine–palustrine successions, with long‐term climate changes being recorded in detail in the isotopic signatures of carbonates. Episodes of tectonic activity induced alluvial fan progradation and lake retraction in the whole basin. Three lacustrine stages have been identified, which support the idea that climate also exerted an important control on sedimentation. The transition between stages 1 and 2 occurred during a tectonically calm episode due to an increase in aridity in the Early Turolian; small fans with source areas next to the lake margin prograded, inducing lake‐shore retraction. The transition from stage 2 to 3 was caused by the superimposition of increasing tectonic activity and aridity effects. Our study demonstrates that discrimination of allogenic factors controlling sedimentation in continental closed basins is possible using sequence stratigraphy in combination with other techniques such as geochemistry of carbonates.  相似文献   
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Boundary-Layer Meteorology - The Obukhov length, although often adopted as a characteristic scale of the atmospheric boundary layer, has been introduced purely based on a dimensional argument...  相似文献   
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Pathogen removal is essential for wastewater treatment and its potential reuse in agriculture. Three field-scale wastewater treatment systems consisting of free surface flow were operated around 1.5 years receiving water from urban domestic, rural domestic and industrial sources. The study was conducted to evaluate seasonal performance of constructed wetland systems in removing Escherichia coli, Enterococci and total coliforms under continuous hydraulic flow. Results displayed that all three wetlands gain recognition in removing pathogen load with high removal efficacy till water reaches output ports. Removal efficiencies were even higher, 66–93, 78–92 and 80–94% for E. coli, Enterococci and total coliforms, respectively, within constructed wetlands. Remarkably at shorter temporal scales in CW-A, greater homogeneity of pathogen concentrations was assessed at wetland outlet sites. In outlet ports, results displayed a highly effective removal of E. coli concentration 80–90% (June 2015), 86–92% (October 2015) and 79–92% (February 2016), Enterococci 80–94% (June 2015), 83–94% (October 2015) and 80–94% (February 2016) and total coliforms 85–93% (June 2015), 87–95% (October 2015) and 88–96% (February 2016). Positive correlation was observed between bacterial indicators (E. coliEnterococci, r = 0.038; p < 0.01 and E. coli–total coliforms, r = 0.142; p < 0.01). Removal of bacterial indicators in constructed wetland was also displayed by PCA in which three-component analysis of variance was 98.39% and showed a clear decrease in measured parameter gradients toward samples from outlet ports. Constructed wetlands provide cost-effective treatment systems for reducing the pathogen load in wastewater in variable agro-climatic conditions and thus improve water quality.  相似文献   
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Groundwater is the most important source of water in meeting irrigation, drinking, and other needs in India. The assessment of the potential zone for its recharge is critical for sustainable usage, quality management, and food security. This study reports alternative mapping of the groundwater recharge potential of a selected block by including large-scale soil data. Thematic layers of soil, geomorphology, slope, land use land cover, topographical wetness index, and drainage density of Darwha block (District Yavatmal, Maharashtra, India) were generated and integrated in a geographic information system environment. The topographic maps, thematic maps, field data, and satellite image were processed, classified, and weighted using analytical hierarchical process for their contribution to groundwater recharge. The layers were integrated by weighted linear combination method in the GIS environment to generate four groundwater potential zones viz., “poor,” “poor to moderate,” “moderate to high,” and “high.” Based on the generated groundwater potential map, about 9830 ha (12%) of the study area was categorized as high potential for recharge, 25,558 ha (31%) as poor to moderate, 33,398 ha (40%) as moderate to high, and 12,565 ha (15%) as poor potential zone. The zonation corresponds well with the field data on greater well density (0.22/ha) and irrigated crop area (27%) in the high potential zone as against 0.02 wells/ha and only 6% irrigated area in the poor zone. The map is recommended for use in regulating groundwater development decisions and judicious expenditure on drilling new wells by farmers and the state authorities.  相似文献   
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Ocean Science Journal - The abundance of bacteria inhabiting the sediment-water interface and their taxonomic composition were determined with the fluorescence in situ hybridization (FISH) method...  相似文献   
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The temporal‐spatial resolution of input data‐induced uncertainty in a watershed‐based water quality model, Hydrologic Simulation Program‐FORTRAN (HSPF), is investigated in this study. The temporal resolution‐induced uncertainty is described using the coefficient of variation (CV). The CV is found to decrease with decreasing temporal resolution and follow a log‐normal relation with time interval for temperature data while it exhibits a power‐law relation for rainfall data. The temporal‐scale uncertainties in the temperature and rainfall data follow a general extreme value distribution and a Weibull distribution, respectively. The Nash‐Sutcliffe coefficient (NSC) is employed to represent the spatial resolution induced uncertainty. The spatial resolution uncertainty in the dissolved oxygen and nitrate‐nitrogen concentrations simulated using HSPF is observed to follow a general extreme value distribution and a log‐normal distribution, respectively. The probability density functions (PDF) provide new insights into the effect of temporal‐scale and spatial resolution of input data on uncertainties involved in watershed modelling and total maximum daily load calculations. This study exhibits non‐symmetric distributions of uncertainty in water quality modelling, which simplify weather and water quality monitoring and reducing the cost involved in flow and water quality monitoring. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
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The stable carbon isotopic compositions of light hydrocarbon gases adsorbed in near-surface soil and sediments from the Saurashtra basin were characterized for their origin and maturity. Saurashtra is considered geologically prospective for oil and gas reserves; however, a major part of the basin is covered by the Deccan Traps, hindering the exploration of Mesozoic hydrocarbon targets. Surface geochemical prospecting, based on micro-seepage of hydrocarbons from subsurface accumulations, could be advantageous in such areas. In light of this, 150 soil samples were collected from the northwestern part of Saurashtra, around the Jamnagar area, where a thick sedimentary sequence of about 2–3 km exists under 1–1.5 km of Deccan basalt. The concentration of acid desorbed alkane gases from soil samples was found to vary (in ppb) as: methane (C1) = 3–518; ethane (C2) = 0–430; propane (C3) = 0–331; i-butane (iC4) = 0–297; n-butane (nC4) = 2–116; i-pentane (iC5) = 0–31 and n-pentane (nC5) = 0–23, respectively.Fifteen samples with high concentrations of alkane gases were measured for their δ13C1; δ13C2 and δ13C3 compositions using gas chromatography–combustion-isotope ratio mass spectrometry (GC–C-IRMS). The values for methane varied from ? 27 to ? 45.4‰, ethane from ? 20.9 to ? 27.6‰, and propane from ? 20.4 to ? 29.1‰ versus the Vienna PeeDee Belemnite (VPDB). The carbon isotope ratio distribution pattern represents isotopic characteristics pertaining to hydrocarbon gases derived from thermogenic sources. Comparisons of carbon isotopic signatures and compositional variations with the standard carbon isotopic models suggest that hydrocarbon gases found in the shallow depths of the study area are not of bacterial origin but are formed thermally from deeply buried organic matter, likely to be mainly a terrestrial source rock with a partial contribution from a marine source. These gases may have migrated to the near-surface environment, where they represent an admixture of thermally generated hydrocarbon gases from mixed sources and maturity. The maturity scale (δ13C versus Log Ro %) applied to the surface sediment samples of the Jamnagar area indicated the source material to be capable of generating oil and gas. The detection of thermogenic alkane gases in near-surface sediments offers the possibility of hydrocarbons at depth in Saurashtra.  相似文献   
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