Frontiers of Earth Science

ISSN 2095-0195

ISSN 2095-0209(Online)

CN 11-5982/P

Postal Subscription Code 80-963

2018 Impact Factor: 1.205

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, Volume 3 Issue 3

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RESEARCH ARTICLE
Magnetic characteristics of topsoil from Xinjiang, Northwestern China, and their implications
Haitao WEI, Dunsheng XIA, Fahu CHEN, Ming JIN, Haibin WANG, Jia JIA
Front Earth Sci Chin. 2009, 3 (3): 259-265.  
https://doi.org/10.1007/s11707-009-0041-5

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In this study, a set of environmental magnetic parameters (χlf, χfd%,χARM, SIRM, HIRM, SOFT and SIRM/χlf, χARM/SIRM and χARM/χlf) of 331 top-soil samples from Xinjiang Uygur Autonomous Region of China were systematically measured and the magnetic characteristics and its environmental significance were discussed. Our results indicate that the main magnetic minerals of these top-soils are single-domain magnetite. The content of magnetic minerals in top-soils from north Xinjiang is higher than that from south Xinjiang; however, the content of hard magnetic minerals is higher in the top-soils from south Xinjiang. The top-soils from Yili region contain similar magnetic minerals as that from south Xinjiang, but with much stronger magnetic SP content due to higher pedogenic processes. The differences in magnetic characteristics among top-soils from different regions of Xinjiang might reflect the differences of regional climatic factors, especially the precipitation.

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CPI values of terrestrial higher plant-derived long-chain n-alkanes: a potential paleoclimatic proxy
Zhiguo RAO, Zhaoyu ZHU, Suping WANG, Guodong JIA, Mingrui QIANG, Yi WU
Front Earth Sci Chin. 2009, 3 (3): 266-272.  
https://doi.org/10.1007/s11707-009-0037-1

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Carbon Preference Index (CPI values) of higher plant-derived long-chain n-alkanes extracted from 62 surface soil samples in eastern China exhibited a specific pattern of variations, namely gradual increase with the increasing latitudes. Such regular variations existed in both forest soil and grassland soil. Our data implied that CPI values of higher plant-derived long-chain n-alkanes had a certain connection with climatic conditions, and such a connection was not influenced by vegetation types. Together with previous data from marine sediments, loess/paleosol sequences, tertiary red clay and modern plants, our observation made us conclude that CPI values of higher plant-derived long-chain n-alkanes may be used as an excellent proxy for paleoclimatic studies.

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Simulation of nitrogen and phosphorus loads in the Dongjiang River basin in South China using SWAT
Yiping WU, Ji CHEN
Front Earth Sci Chin. 2009, 3 (3): 273-278.  
https://doi.org/10.1007/s11707-009-0032-6

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Population growth, urbanization, and intensified agriculture have resulted in mobilization of nitrogen and phosphorus, which is the main cause of river water quality deterioration. Environmental regulation has expedited the necessity for agricultural producers to design and implement more environmentally suitable practices. Therefore, there is a need to identify critical nutrients and their loss/transport potential. Watershed model can be used to better understand the relationship between land use activities/management and hydrologic processes/water quality changes that occur within a watershed. The objective of the study is to test the performance of the SWAT model and the feasibility of using this model as a simulator of water flow and nitrogen and phosphorus yields over the Dongjiang River basin in South China.

Spatial data layers of land slope, soil type, and land use were combined with geographic information system (GIS) to aid in creating model inputs. The observed streamflow and sediment at Boluo station in the Dongjiang River basin were used to calibrate and validate the model. Time series plots and statistical measures were used to verify model predictions. Predicted values generally matched well with the observed values during calibration and validation (R20.6 and Nash-Suttcliffe Efficiency 0.5) except for underestimation of sediment peaks and overestimation of sediment valleys at Boluo. This study shows that SWAT is able to predict streamflow, sediment generation, and nutrients transport with satisfactory results.

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Response of geochemical records in lacustrine sediments to climate change and human impact during middle Holocene in Mengjin, Henan Province, China
Guanghui DONG, Zhengkai XIA, Robert ELSTON, Xiongwei SUN, Fahu CHEN
Front Earth Sci Chin. 2009, 3 (3): 279-285.  
https://doi.org/10.1007/s11707-009-0038-0

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In this paper, we examined the response of geochemical records in lacustrine sediments to climate and human activity in Mengjin, Henan Province of China during the middle Holocene. Indices used in this study include K, Na, Mn, Ba, Sr, Al, Ti, cation ratios, and Gramineae pollen in lacustrine sediments. Results indicate a drought event in this area around 5660 cal a BP, which weakened soil leaching and changed the element composition of surface soil runoff entering the paelo-lake and lacustrine sediments. Human activity appearing from 4695 cal a BP to 4000 cal a BP also affected the chemical composition of lake sediments. Human activities led to enhanced soil erosion and destroyed soil leaching horizons. Therefore, the substance of soil illuvial layer exposed to the surface and entering the paleo-lake were substantially altered by human activities.

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Huayanpeng boulder beach of Putuo Island, southeast coast of China: characteristics and explanation
Bin CHEN, Zhongyuan CHEN
Front Earth Sci Chin. 2009, 3 (3): 286-290.  
https://doi.org/10.1007/s11707-009-0026-4

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Huayanpeng boulder beach is located at the Cape of Putuo Island, southeast coast of China. From 6000 years ago, sea level changed little and turned steady, which was prone to forming the boulder beach. Since then, numerous storm surges propagated from the West Pacific Ocean have imposed on the bedrock of the eastern coast of Putuo Island, resulting in a large amount of rocks fallen from the hill-slope onto the beach. The similarity of rock lithology between the bedrock and the boulders of the study area supports the hypothesis of Holocene steady sea-level controls on the formation of the beach. Long-term littoral currents, including storm weather and normal weather conditions, have greatly sorted the boulder beach vertically and transversely. From east to west, the beach turns wider and gradient becomes gentler, and the boulders reduce its size, from, on average, 1.0 m to 0.5 m, with a decrease in flattening and an increase in sphericity and psephicity. The sizes of the boulders and flattening turn bigger from supra-littoral to inter-littoral zone, while sphericity and psephicity turn smaller and lower. These basal characteristics of boulders highlight the linkage of beach formation to the high-storm energy propagated from the open seas during the typhoon season.

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Climate implications of major geochemical elements in the Holocene sediments of the North and East China monsoonal regions
Qianli SUN, Zhanghua WANG, Jing CHEN, Wu FENG
Front Earth Sci Chin. 2009, 3 (3): 291-296.  
https://doi.org/10.1007/s11707-009-0035-3

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Two Holocene sediment cores were retrieved respectively from the enclosed Lake Daihai in the monsoon/arid transition zone of North China and the Taihu Lake coast in the monsoonal area of the Yangtze delta, Eastern China. Distribution of major geochemical elements and their ratios were employed to reveal the characteristics of Holocene climate and associated environmental implications in the two regions. It is suggested that the temporal distribution of major elements serve as a useful indicator to denote the variations of monsoon effective precipitation for the enclosed lake area. High values of resistant elements such as Al2O3, SiO2, TiO2, (FeO+Fe2O3), MnO in the lake sediments correspond to the depressed chemical weathering and weakened monsoon effective precipitation, while the highs of mobile and easy soluble elements such as MgO, CaO, Na2O reflect the enhanced chemical weathering and increased monsoon effective precipitation in the lake basin. In comparison, the behaviors of the major elements in sediments of the Taihu Lake coast were largely controlled by the changes both in sea transgression in the different Holocene time periods and the monsoon precipitation. The relatively highs of Al2O3, TiO2, (FeO+Fe2O3), in marine-influenced sediments suggest relatively strong coastal hydrodynamics and chemical weathering, and vice versa. Meanwhile, the lows of SiO2, Na2O and CaO in the non-marine-influenced sediments also denote relatively strong hydrodynamics and chemical weathering due to enhanced monsoon precipitation, and vice versa. Sedimentary environment should be taken into account when achieving a full understanding of their climate implications.

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Effect of rainfall and antecedent dry periods on heavy metal loading of sediments on urban roads
Peng TIAN, Yingxia LI, Zhifeng YANG
Front Earth Sci Chin. 2009, 3 (3): 297-302.  
https://doi.org/10.1007/s11707-009-0042-4

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Concentration and mass loadings of heavy metals adsorbed on sediment from an urban road surface in Beijing were investigated. The buildup and washoff processes are discussed. Results showed that masses of sediments smaller than 500 μm in diameter varied from 11.2 to 25.5 g/m2. On average, sediments smaller than 125?μm accounted for 42.9% of sediments smaller than 500 μm in mass. Cd, Cr, Cu, and Ni were more likely to attach to smaller sediments than bigger ones, compared to Pb and Zn. Mass loading of the sediments generally increased with antecedent dry periods, but the linear relationship was better for smaller sediments than for bigger ones. Heavy metal concentrations adsorbed on sediments with diameter less than 40?μm generally decreased more obviously than those adsorbed on bigger ones after rainfall events.

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REVIEW ARTICLE
A review on soil cover in waste and contaminant containment: design, monitoring, and modeling
Sheng PENG, Huilian JIANG
Front Earth Sci Chin. 2009, 3 (3): 303-311.  
https://doi.org/10.1007/s11707-009-0046-0

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Soil cover is a widely-used but relatively new method for solid waste containment. Standard while site-specific procedures for cover design, monitoring, and evluation are needed to insure reliable cover performance. This paper presents a review of soil cover types, design principles and procedures, cover monitoring, Cover types and cover design are introduced with the general concepts and discussed on their specific applicabilities in different circumstances. and long-term performance modeling. Detailed discussion is given on unsaturated flow system properties and their field measurements, including methods, apparatuses/equipments and their advantages and disadvantages. Several unsaturated flow simulators are discussed and compared with regards to their simulation capacities for critical parameters closely related to soil cover performance such as runoff, infiltration and evaporation. Finally, research subjects are suggested for future work for better soil cover monitoring and modeling.

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RESEARCH ARTICLE
Township ecosystem health assessment based on fuzzy synthesis evaluation method: a case study of Tongzhou District, Beijing, China
Shan SHAN, Lina ZHANG, Xuan WANG, Bin CHEN
Front Earth Sci Chin. 2009, 3 (3): 312-319.  
https://doi.org/10.1007/s11707-009-0031-7

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With the quick development of urbanization, the urban environmental problem has broken out in rural towns. In this study, a reasonable review of the research progress in the field of urban ecosystem health was addressed. Based on the analysis of the structure-function characteristics of the compound ecosystem, the connotation of the township ecosystem health was determined. Then ecosystem health of eleven towns of Tongzhou District was evaluated. This was accomplished by first constructing an index system including three layers which were criterion, factor and index. The criterion layer contained five elements including vigor, organization structure, resilience, ecosystem service function and population health. The indicators amounted in the aggregate to twenty-two. Then the health assessment of the study area was carried out using the fuzzy synthesis evaluation method. The evaluation results were analyzed by GIS techniques. Comprehensive analysis for integral health has shown that eight towns are in sub-healthy conditions, and the other three towns of Songzhuang, Xiji and Yongledian are healthy.

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Occurrence of highly abundant bacterial hopanoids in Dajiuhu peatland, central China
Ze ZHANG, Canfa WANG, Xuan QIU, Xianyu HUANG, Shucheng XIE
Front Earth Sci Chin. 2009, 3 (3): 320-326.  
https://doi.org/10.1007/s11707-009-0039-z

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Based on gas chromatography and gas chromatography-mass spectrometry analyses, an amazing amount of hopanoids were detected in the peat deposits in the Dajiuhu National Wetland Park in Central China. The hopanoids identified included hopanes (C27–C31 αβ, C27–C32 ββ, C29 βα), hopenes (hop-22(29)-ene, 22,29,30-trinorhop-17(21)-ene, hop-17(21)-ene, hop-13(18)-ene, etc.), hopanoic acids (C31–C34 ββ, C32–C33 βα, C32 αβ), hopanols (C32 ββ and αβ) and hopanone (22,29,30-trinor-hop-21-one). C31 αβ-22R hopane was found to be the dominant hopanoid, more abundant than individual n-alkanes derived from higher plants. These hopanoids, exclusive of some hopenes, are proposed to be primarily from bacteria. The dominant C31 αβ-22R hopane in young sediments, without any thermal maturation, might be formed through microbial epimerization under acidic conditions in the peatland as suggested before, or directly from aerobic bacteria. This finding highlights the importance of microbes in the formation of peatland as well as in the reconstruction of paleoenvironments.

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n-alkane distribution coupled with organic carbon isotope composition in shell bar section, Qarhan paleolake, Qaidam basin, NE Tibetan Plateau
Yang PU, Hucai ZHANG, Guoliang LEI, Fengqin CHANG, Mingsheng YANG, Xianyu HUANG
Front Earth Sci Chin. 2009, 3 (3): 327-335.  
https://doi.org/10.1007/s11707-009-0044-2

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Lipids extracted from lacustrine deposits in the paleolake Qarhan of the Qaidam basin in the northeastern Tibetan Plateau were determined by conventional gas chromatography-mass spectrometry. Several series of biomarkers were identified, mainly including n-alkanes, n-alkan-2-ones, n-alkanoic acids, branched alkanes, triterpenoids and steroids, indicative of various biogenic contributions. On the basis of cluster analysis, the n-C15, n-C17, n-C19 alkanes were proposed to be derived from algae and/or photosynthetic bacteria, the n-C21, n-C23, n-C25 homologues from aquatic plants, and the n-C29, n-C31 homologues from vascular plants. In contrast, the n-C27 alkane is not categorized in the n-C29 and n-C31 group of alkanes, probably due to more complex origins including both aquatic and vascular plants, and/or differential biodegradation. Stratigraphically, layers-2, 4 and 5 were found to show a close relationship in n-alkane distribution, associated with a positive shift in carbon isotope composition of bulk organic matter (δ13Corg), inferring a cold/dry period. Layers-1 and 6 were clustered together in association with a negative δ13Corg excursion, probably indicating a relatively warm/humid climate. The potential coupling between the n-alkane distributions and δ13Corg, suggests a consequence of vegetation change in response to climate change, with the late MIS3 being shown to be unstable, thought to be the climatic optimum in the Tibetan Plateau. Our results suggest that the cluster analysis used in this study probably provides an effective and authentic method to investigate the n-alkane distribution in paleolake sediments.

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Stress of urban energy consumption on air environment
Gang YAN, Li LI, Bin CHEN
Front Earth Sci Chin. 2009, 3 (3): 337-348.  
https://doi.org/10.1007/s11707-009-0045-1

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With rapid urbanization and heavy industrialization as well as the rapid increase of cars in China, the effect of energy consumption on urban air environment is increasingly becoming serious, and has become a hot topic for both scholars and decision-makers. This paper explores the effect mechanism and regulation of urban energy consumption on the air environment, and summarizes the framework of the stress effect relationship and the evolutionary process. In accordance with the effect relationship of the internal factors between the two, analytic approaches studying the stress effect of urban energy consumption on air environment are proposed, including the analysis of air environment effects caused by urban energy consumption structure change, and the analysis of air environment effects caused by urban energy economic efficiency change, as well as a decomposition analysis of air pollutant emission caused by urban energy consumption. Applying the above-mentioned approaches into a case study on Beijing City, this paper analyzes the effect relationship among urban energy consumption structure improvement, energy economic efficiency increase and air quality change since the period when Beijing City officially proposed to bid for the 2008 Olympic Games in 1998. In addition, it further analyzes the effect and contribution of urban industrial activity level, industrial economic structure, industrial energy intensity, and industrial energy structure as well as emission coefficients on the change in industrial SO2 emission, which can provide valuable information to the government for making comprehensive environmental policies, with the use of the logarithmic mean Divisia index (LMDI) method. It is shown that under the precondition that the industrial economy maintain a continuous and rapid increase, improvements in energy intensity and a decline in emission coefficients are the main means for reducing Beijing’s industrial SO2 emissions.

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Simulation analysis of domestic water demand and its future uncertainty in water scarce areas
Shouke WEI, Albrecht GNAUCK, Alin LEI
Front Earth Sci Chin. 2009, 3 (3): 349-360.  
https://doi.org/10.1007/s11707-009-0047-z

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This paper demonstrates a practical simulation approach to analyze domestic water demand and its future uncertainty in water scarce areas through a case study of Beijing, China. Analytic models and a forecasting model were constructed using statistic and econometric regression approaches. The analytic models were used to analyze the interrelationships between domestic water demand and some socio-economic factors of Beijing. The forecasting model was applied to predict domestic water demand from 2009 to 2015, and this model was validated by comparing the prediction values with the observations. Scenario analysis was applied to simulate uncertainty and risks in domestic water demand in the future. The simulation results proved that domestic water demand will increase from 13.9×108 m3 to 16.7×108 m3 from 2009 to 2015. Three more sustainable strategies were also found through scenario analysis. The simulation and modeling approaches and results would be very supportive for water decision makers in allocating water efficiently and making sustainable water strategies.

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A granulation model using diosgenin wastewater in an upflow anaerobic sludge blanket reactor
Jianguo BAO, Hui LIU, Yanxin WANG, Lijun ZHANG
Front Earth Sci Chin. 2009, 3 (3): 361-366.  
https://doi.org/10.1007/s11707-009-0030-8

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An enhanced start-up of an upflow anaerobic sludge blanket (UASB) reactor for diosgenin wastewater treatment was designed and experimentally tested. Granular sludge was formed on day 35 in the reactor with high concentrations of chloride (4000-7000 mg/L) and COD (5000-13000 mg/L) as substrate. A new model for the granulation was proposed which divides the formation of anaerobic granules into six consecutive stages; they include semi-embryonic granule formation, embryonic granule formation, single-nucleus granule formation, multi-nuclei granule formation, granule growth and granule maturation. A model of the granule structure was also proposed based on scanning electron microscope observation. The microspores occurring on the surface and further leading into the interior of the granules were considered as the channels and the passage of the materials and the products of the microorganisms’ metabolism inside the granules.

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General introduction on payloads, ground segment and data application of Fengyun 3A
Peng ZHANG, Jun YANG, Chaohua DONG, Naimeng LU, Zhongdong YANG, Jinmin SHI
Front Earth Sci Chin. 2009, 3 (3): 367-373.  
https://doi.org/10.1007/s11707-009-0036-2

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Fengyun 3 series are the second-generation polar-orbiting meteorological satellites of China. The first satellite of Fengyun 3 series, FY-3A, is a research and development satellite with 11 payloads onboard. FY-3A was launched successfully at 11 a.m. on May 27, 2008. Since the launch, FY-3A data have been applied to the services on the flood season and the Beijing 2008 Olympic Games. In this paper, the platform, payloads, and ground segment designs are introduced. Some typical images during the on-orbit commission test are rendered. Improvements of FY-3A on Earth observations are summarized at the end by comparing them with FY-1D, the last satellite of Fengyun 1 series.

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Parameters optimization on DHSVM model based on a genetic algorithm
Changqing YAO, Zhifeng YANG
Front Earth Sci Chin. 2009, 3 (3): 374-380.  
https://doi.org/10.1007/s11707-009-0040-6

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Due to the multiplicity of factors including weather, the underlying surface and human activities, the complexity of parameter optimization for a distributed hydrological model of a watershed land surface goes far beyond the capability of traditional optimization methods. The genetic algorithm is a new attempt to find a solution to this problem. A genetic algorithm design on the Distributed-Hydrology-Soil-Vegetation model (DHSVM) parameter optimization is illustrated in this paper by defining the encoding method, designing the fitness value function, devising the genetic operators, selecting the arithmetic parameters and identifying the arithmetic termination conditions. Finally, a case study of the optimization method is implemented on the Lushi Watershed of the Yellow River Basin and achieves satisfactory results of parameter estimation. The result shows that the genetic algorithm is feasible in optimizing parameters of the DHSVM model.

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16 articles