scholarly journals Selected Grain-Size and Geochemical Analyses of the Loess-Paleosol Sequence of Pécel (Northern Hungary): An Attempt to Determine Sediment Accumulation Conditions and the Source Area Location

Quaternary ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 17
Author(s):  
László Makó ◽  
Dávid Molnár ◽  
Boglárka Runa ◽  
Gábor Bozsó ◽  
Péter Cseh ◽  
...  
Keyword(s):  
Composition Studies ◽  
Sediment Accumulation ◽  
Source Area ◽  
Sufficient Information ◽  
Source Areas ◽  
Sulphide Minerals ◽  
The Past ◽  
Geochemical Indices ◽  
Geochemical Analyses ◽  
Buda Thermal Karst

The loess-paleosol profile near the settlement of Pécel has a notable size among the loess-paleosol sequences of the Northern Carpathian territories. Therefore, comprehensive sedimentological examinations were performed to understand the profile and the information preserved in it. The past periodicity and intensity of winds were showed by particle composition studies (GSI, U-ratio). At least two source areas can be presumed based on geochemical indices (CIA, CIW, Rb/Sr, Zr/Rb). Based on the characteristics of the chemical composition of sulphide minerals (P, S, Pb, Ni, As sulphides), the lower 10 m of the profile was supposed to be transported from the NW direction (Buda Thermal Karst, Börzsöny, Cserhát). Sufficient information is not yet available in order to determine the source area of the upper 10 m. By using the mentioned indexes, major developing and weathering horizons also could be identified.

scholarly journals Correction of Eddy Covariance Based Crop ET Considering the Heat Flux Source Area

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 281
Author(s):  
Stuart L. Joy ◽  
José L. Chávez
Keyword(s):  
Heat Flux ◽  
Eddy Covariance ◽  
Agricultural Land ◽  
Flux Measurement ◽  
Source Area ◽  
Mean Bias Error ◽  
Bias Error ◽  
Crop Water ◽  
The Past ◽  
Measurement Results

Eddy covariance (EC) systems are being used to measure sensible heat (H) and latent heat (LE) fluxes in order to determine crop water use or evapotranspiration (ET). The reliability of EC measurements depends on meeting certain meteorological assumptions; the most important of such are horizontal homogeneity, stationarity, and non-advective conditions. Over heterogeneous surfaces, the spatial context of the measurement must be known in order to properly interpret the magnitude of the heat flux measurement results. Over the past decades, there has been a proliferation of ‘heat flux source area’ (i.e., footprint) modeling studies, but only a few have explored the accuracy of the models over heterogeneous agricultural land. A composite ET estimate was created by using the estimated footprint weights for an EC system in the upwind corner of four fields and separate ET estimates from each of these fields. Three analytical footprint models were evaluated by comparing the composite ET to the measured ET. All three models performed consistently well, with an average mean bias error (MBE) of about −0.03 mm h−1 (−4.4%) and root mean square error (RMSE) of 0.09 mm h−1 (10.9%). The same three footprint models were then used to adjust the EC-measured ET to account for the fraction of the footprint that extended beyond the field of interest. The effectiveness of the footprint adjustment was determined by comparing the adjusted ET estimates with the lysimetric ET measurements from within the same field. This correction decreased the absolute hourly ET MBE by 8%, and the RMSE by 1%.

scholarly journals An efficient semi-distributed hillslope erosion model for the subhumid Ethiopian Highlands

2013 ◽  
Vol 17 (3) ◽  
pp. 1051-1063 ◽  
Author(s):  
S. A. Tilahun ◽  
C. D. Guzman ◽  
A. D. Zegeye ◽  
T. A. Engda ◽  
A. S. Collick ◽  
...  
Keyword(s):  
Surface Runoff ◽  
Source Area ◽  
Sediment Concentration ◽  
Erosion Model ◽  
Ethiopian Highlands ◽  
Source Areas ◽  
Blue Nile Basin ◽  
Field Evidence ◽  
Sediment Loss ◽  
Main Variable

Abstract. Erosion modeling has been generally scaling up from plot scale but not based on landscape topographic position, which is a main variable in saturation excess runoff. In addition, predicting sediment loss in Africa has been hampered by using models developed in western countries and do not perform as well in the monsoon climate prevailing in most of the continent. The objective of this paper is to develop a simple erosion model that can be used in the Ethiopian Highlands in Africa. We base our sediment prediction on a simple distributed saturated excess hydrology model that predicts surface runoff from severely degraded lands and from bottom lands that become saturated during the rainy season and estimates interflow and baseflow from the remaining portions of the landscape. By developing an equation that relates surface runoff to sediment concentration generated from runoff source areas, assuming that baseflow and interflow are sediment-free, we were able to predict daily sediment concentrations from the Anjeni watershed with a Nash–Sutcliffe efficiency ranging from 0.64 to 0.78 using only two calibrated sediment parameters. Anjeni is a 113 ha watershed in the 17.4 million ha Blue Nile Basin in the Ethiopian Highlands. The discharge of the two watersheds was predicted with Nash–Sutcliffe efficiency values ranging from 0.80 to 0.93. The calibrated values in Anjeni for degraded (14%) and saturated (2%) runoff source area were in agreement with field evidence. The analysis suggests that identifying the runoff source areas and predicting the surface runoff correctly is an important step in predicting the sediment concentration.

scholarly journals Lake-level variability in Salar de Coipasa, Bolivia during the past ∼40,000 yr

2018 ◽  
Vol 91 (2) ◽  
pp. 881-891 ◽  
Author(s):  
J. Andrew Nunnery ◽  
Sherilyn C. Fritz ◽  
Paul A. Baker ◽  
Wout Salenbien
Keyword(s):  
Lake Level ◽  
Sediment Accumulation ◽  
Geochemical Data ◽  
South American ◽  
Climate History ◽  
Oxygen Isotope Stage ◽  
The Past ◽  
History Of ◽  
Diatom Stratigraphy ◽  
The Last Glacial

AbstractVarious paleoclimatic records have been used to reconstruct the hydrologic history of the Altiplano, relating this history to past variability of the South American summer monsoon. Prior studies of the southern Altiplano, the location of the world’s largest salt flat, the Salar de Uyuni, and its neighbor, the Salar de Coipasa, generally agree in their reconstructions of the climate history of the past ∼24 ka. Some studies, however, have highly divergent climatic records and interpretations of earlier periods. In this study, lake-level variation was reconstructed from a ∼14-m-long sediment core from the Salar de Coipasa. These sediments span the last ∼40 ka. Lacustrine sediment accumulation was apparently continuous in the basin from ∼40 to 6 ka, with dry or very shallow conditions afterward. The fossil diatom stratigraphy and geochemical data (δ13C, δ15N, %Ca, C/N) indicate fluctuations in lake level from shallow to moderately deep, with the deepest conditions correlative with the Heinrich-1 and Younger Dryas events. The stratigraphy shows a continuous lake of variable depth and salinity during the last glacial maximum and latter stages of Marine Oxygen Isotope Stage 3 and is consistent with environmental inferences and the original chronology of a drill core from Salar de Uyuni.

scholarly journals Dragos Gheorghiu, Livia Stefan, Immersing into the Past: an Augmented Reality Method to Link Tangible and Intangible Heritage

2020 ◽  
Vol 8 (2) ◽  
pp. 91-102
Author(s):  
Dragos Gheorghiu ◽  
Livia Stefan
Keyword(s):  
Augmented Reality ◽  
Research Work ◽  
Modern Method ◽  
Sufficient Information ◽  
Efficient Manner ◽  
The Past ◽  
Intangible Heritage ◽  
Points Of Interest ◽  
Local Material ◽  
World Information

The current IT and digital technologies such as Mobile Augmented Reality (MAR) enable the overlap of digital and real world information in relation with a topic, in an engaging and efficient manner, and therefore can be used to store intangible heritage and to study it in the context as well. The current paper refers to such an augmentation of cultural information, performed at the Kallatis site, whose ruins, at present mostly covered by the modern town, do not offer sufficient information on the complexity of the Greek civilization. The implementation of a MAR application consisted in defining several points of interest of the important local archaeologic discoveries, which can trigger, for the visitors using our application, an augmentation of the historical site with images and videos. With the current research work, the authors propose and demonstrate that a mobile MAR application can constitute a modern method for providing visitors with an immersive and holistic experience for understanding the local material and intangible heritage.

Spatial heterogeneity of debris-flow watershed

2021 ◽  
Author(s):  
Yingjie Yao
Keyword(s):  
Potential Energy ◽  
Debris Flow ◽  
Spatial Autocorrelation ◽  
Gravitational Potential ◽  
Source Area ◽  
Geospatial Analysis ◽  
Gravitational Potential Energy ◽  
Source Areas ◽  
Hypsometric Analysis ◽  
Inflection Points

<p>The intermittent surge is the basic manifestation of viscous debris flow, which emerges universally over the world, especially exemplified by those in Jiangjia Gully (JJG), a valley famous for its high frequency and variety of debris flow surges. It has been found that the surges originate from various sources in the watershed, thus identifying the source areas plays a fundamental role in studying the mechanism and process of surge developing. Advancement of GIS provides an apparent convenience in geospatial analysis of the watershed, which is used as a dominate tool in this paper.</p><p>In this study the JJG is divided into 97 tributaries (sub-watershed) and the hypsometric analysis is performed for each, from which derive the height of inflection points and the gravitational potential energy, coupled with the fitted parameters of specific power function. Then the morphology parameters, including slope, roundness, vegetation and soil, are revealed in tributaries. Besides, spatial autocorrelation among tributaries is quantified both globally and locally through Moran’s I and Getis-Ord G<sub>i</sub>*, so that the HI spatial distributions are quantified and visualized. In particular, hot spots are conspicuously visible and highlight the geologic meaning of the HI when exploratory spatial data analysis is applied to the data distributions through local indices of spatial autocorrelation.</p><p>The results show that H-curves approximately present as S-shaped, and the integral values (HI) range from 0.18 to 0.69 and show positive relationship with both gravitational potential energy and the height of the inflection points. By the HI value, the tributaries are identified as in 5 phases of evolution. The younger tributaries (HI>0.49) make up the majority, which are expected to be the main possible sources for debris flows. Additionally, the slope distribution of tributaries all conform to the extreme distribution while the curves for the upstream, where the HI of tributaries generally manifest higher coupled with larger roundness, tends to skew to the right.</p><p>Finally the correlation between possible sources are explored through geospatial analysis. The spatial association in JJG provides an explanation of the debris flow source areas. Global spatial autocorrelation manifests significantly clustered (Moran’s I shows 0.449, passing the significance test) while tributaries with high HI value concentrate mainly in the Menqian Valley. Moreover, the drainage form of Menqian Valley represents a large possibility of debris flow source area with the respect of that being in Duozhao Valley.</p><p><strong>Keywords: </strong>debris flow source area; hypsometric analysis; topographical characteristics; spatial autocorrelation; evolutionary phases</p>

scholarly journals The Occurrence and Risks of Selected Emerging Pollutants in Drinking Water Source Areas in Henan, China

2019 ◽  
Vol 16 (21) ◽  
pp. 4109 ◽  
Author(s):  
Donghai Wu ◽  
Ying Zhou ◽  
Guanghua Lu ◽  
Kai Hu ◽  
Jingjing Yao ◽  
...  
Keyword(s):  
Drinking Water ◽  
Hazard Index ◽  
Source Area ◽  
Dry Weight ◽  
Water Source ◽  
Triphenylphosphine Oxide ◽  
Drinking Water Source ◽  
Uv Filters ◽  
Source Areas ◽  
Total Concentrations

The occurrence of organic micropollutants (OMPs) in aqueous environments has potential effects on ecological safety and human health. Three kinds of OMPs (namely, pharmaceuticals, ultraviolet (UV) filters and organophosphate esters (OPEs)) in four drinking water source areas in Henan Province of China were analyzed, and their potential risks were evaluated. Among 48 target chemicals, 37 pollutants with total concentrations ranging from 403.0 to 1751.6 ng/L were detected in water, and 13 contaminants with total concentrations from 326.0 to 1465.4 ng/g (dry weight) were observed in sediment. The aqueous pollution levels in Jiangang Reservoir and Shahe Water Source Area were higher than that in Nanwan Reservoir and Baiguishan Reservoir, while the highest total amount of pollutants in sediment was found in Baiguishan Reservoir. Compared with pharmaceuticals and UV filters, OPEs presented higher concentrations in all investigated drinking water source areas. The highest observed concentration was triphenylphosphine oxide (TPPO, 865.2 ng/L) in water and tripentyl phosphate (TPeP, 1289.8 ng/g) in sediment. Moreover, the risk quotient (RQ) analysis implies that the determined aqueous contaminants exhibited high risks to algae and invertebrates, whereas moderate risk to fish was exhibited. The health risk assessment of aqueous OMPs by means of the hazard index (HI) indicates that the risks to adults and children were negligible. These observations are expected to provide useful information for the assessment of water quality in drinking water sources in Henan, China.

Holocene vegetation history in the Northern Vosges Mountains (NE France): Palynological, geochemical and sedimentological data

The Holocene ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 888-904
Author(s):  
Emilie Gouriveau ◽  
Pascale Ruffaldi ◽  
Loïc Duchamp ◽  
Vincent Robin ◽  
Annik Schnitzler ◽  
...  
Keyword(s):  
Bronze Age ◽  
Human Activities ◽  
Vegetation History ◽  
Second Phase ◽  
Human Occupation ◽  
Vosges Mountains ◽  
The Past ◽  
History Of ◽  
Geochemical Analyses ◽  
Evolution Of Vegetation

Palynological data from the Northern Vosges Mountains (NVM) are very rare, unlike for the Southern and Central Vosges Mountains, where the past vegetation history is relatively well known. As a consequence, the beginning of human activities has never been clearly identified and dated in the NVM. In order to reconstruct the evolution of vegetation in this region, multiproxy studies (pollen, non-pollen palynomorphs, sedimentological and geochemical analyses) were conducted in two peatlands. Overall, the results, extending from about 9500 cal. BP to recent times, show a classical vegetation succession with local particularities resulting from human activities. In the La Horn peatland, a strong human impact related to pastoralism is attested from the late Bronze Age onwards. The second phase of human occupation, mainly characterized by crop cultures, begins during the Hallstatt period. The geochemical results (x-ray fluorescence) also highlight the presence of metallic elements, which, combined with significant quantities of carbonized particles, point to potential metal working. In the Kobert-Haut peatland, human occupation began much later (1500 cal. BP), but lasted from the Gallo-Roman period to the beginning of the Modern Period. Unlike for the vegetation history of the rest of the Vosges, Pinus remains a prevailing taxon throughout the Holocene in the NVM. Another particularity is the early establishment of Picea, long before the 18th to 19th century plantations.

scholarly journals Rural Households’ Willingness to Accept Compensation Standards for Controlling Agricultural Non-Point Source Pollution: A Case Study of the Qinba Water Source Area in Northwest China

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1251 ◽  
Author(s):  
Xiaoping Li ◽  
Wenxin Liu ◽  
Yan Yan ◽  
Gongyuan Fan ◽  
Minjuan Zhao
Keyword(s):  
Rural Households ◽  
Source Area ◽  
Water Source ◽  
Willingness To Accept ◽  
Point Source Pollution ◽  
Ecological Benefits ◽  
Source Areas ◽  
Compensation Standard ◽  
Non Point Source Pollution ◽  
Willingness To Accept Compensation

Agricultural non-point source pollution (ANSP) has become one of the main sources of pollution in water source areas. An effective solution to this problem is the use of ecological compensation to encourage rural households to adopt agricultural pollution control measures. This study aims to answer two questions: How much compensation should be given to encourage rural households in water source areas to participate in ANSP control? What factors will influence their participation? In this study, paddy rice planting in water source area has been used as an example aiming to answer these questions. This study used the random parameter logit (RPL) model with survey data from 632 rural households in the Qinba water source area to empirically analyze rural households’ willingness to accept compensation for ANSP control and the influencing factors of this willingness. From this information, the compensation standards for ANSP control in a water source area were calculated. The results show that (1) compensation had a significant incentive effect on rural households’ willingness to control ANSP. The marginal compensation standard for reducing the use of fertilizer and pesticide was $3.40/ha and $2.00/ha, respectively. The compensation standard for not applying chemical fertilizer and pesticide at all was $540.23/ha. (2) There was heterogeneity in rural households’ preference for ANSP control compensation policies. Rural households characterized by younger residents, higher family income, higher perception of the ecological benefits, and higher perception of government policy were more willing to participate in the compensation policy. It is suggested that rural households showed a strong preference for ANSP control policies by considering both of their economic losses and ecological benefits. Our study contributes to the literature by enriching the evaluation method in providing references for the compensation of ANSP control policies

Resistance of zircons to U–Pb resetting in a prograde metamorphic sequence of Caledonian age in East Greenland

1985 ◽  
Vol 22 (3) ◽  
pp. 330-338 ◽  
Author(s):  
J. J. Peucat ◽  
D. Tisserant ◽  
R. Caby ◽  
N. Clauer
Keyword(s):  
Source Area ◽  
Detrital Zircons ◽  
Metamorphic Event ◽  
Great Resistance ◽  
East Greenland ◽  
Geological Interpretation ◽  
Source Areas ◽  
Metasedimentary Rocks ◽  
Sedimentary Source

In the Alpefjord area, Caledonian metamorphism from the chlorite zone to the sillimanite zone is seen to cut across the sedimentary pile of the lower Eleonore Bay Group. Zircons have been collected from quartzite layers enriched in heavy minerals.U–Pb zircon dating in the chlorite and the sillimanite zones does not reveal the Caledonian event but, instead, previous episodes at 1100 and 2500 Ma ago. The Caledonian event can be recognized in anatectic gneisses where detrital zircons are surrounded by overgrowths, K–Ar and Rb–Sr methods yield 1030–410 Ma ages on micas, with a positive correlation between the degree of apparent reselling of mica ages and the grade of the Caledonian metamorphism.The following geological interpretation of the age data is proposed. (1) A major metamorphic event occurred around 1100 Ma ago in the source area for the lower Eleonore Bay Group sediments. During this Grenvillian event, Archaean detrital zircons were affected by an episodic lead loss and a muscovite phase recorded the cooling and uplift of a basement source area. (2) Erosion of this source area occurred after 1100 Ma, followed by sedimentation of the lower Eleonore Bay Group [Formula: see text]. The 2500–1100 Ma U–Pb system remained nearly a closed system during Caledonian metamorphism up to and including sillimanite-zone conditions.This example shows the great resistance or inherited zircons to an important secondary Pb loss during Caledonian metamorphism and consequently shows that the lower-intercept ages of zircons from metasedimentary rocks do not always record the last metamorphic event observed in situ, but retain memories of previous geological events in the sedimentary source areas. By contrast, zircons separated from quartzitic xenoliths in migmatitic gneisses have recorded a disturbance in their U–Pb systems that corresponds to Caledonian partial melting.

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