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

   Online First

Administered by

, Volume 3 Issue 4

For Selected: View Abstracts Toggle Thumbnails
Research articles
Variability and stability of water resource in the arid regions of China: a case study of the Tarim River basin
Qiang ZHANG, Chong-Yu XU, Hui TAO,
Front. Earth Sci.. 2009, 3 (4): 381-388.  
https://doi.org/10.1007/s11707-009-0050-4

Abstract   PDF (374KB)
In this study, we analyzed two long term streamflow records of the Aksu River basin, the main water source of the Tarim River basin, using multiscale t-test and F-test with the aim to understand the changing characteristics of hydrological regimes in terms of the first moment (mean or average) and the second moment (variance). The results indicate the following: 1) In general, increasing streamflow was observed in two periods: 1965―1970 and 1980―1985. Since 1986, the streamflow of the Aksu River has been persistently increasing. 2) Synchronous variations can be found between the subseries variance and the subseries mean, i.e., an increase in the subseries mean is usually consistent with an increase in the subseries variance, and vice versa. Therefore, streamflow changes of the Aksu River tend to be unsteady, although streamflow is persistently increasing since 1986. 3) The streamflow changes of the Aksu River are heavily dependent on precipitation and ice melting. Increase of precipitation and more ice melting in recent decades, particularly after the 1980s, are the major causes of streamflow changes of the Aksu River basin.
References | Related Articles | Metrics
Spatio-temporal analysis of different levels of road expansion on soil erosion distribution: a case study of Fengqing county, Southwest China
Zhaoling ZHANG, Shiliang LIU, Shikui DONG, Wei FU, Baoshan CUI,
Front. Earth Sci.. 2009, 3 (4): 389-396.  
https://doi.org/10.1007/s11707-009-0058-9

Abstract   PDF (399KB)
The construction of roads has direct and indirect impacts on soil erosion, with spatio-temporal variations existing among different levels of road zones. Aiming to quantitatively analyze the soil loss, this paper explored the relationship between the erosion of soil and its distance from the road in Fengqing county, Southwest China in 1987 and 2004, respectively. The average soil erosion was calculated and expressed with grid map using universal soil loss equation (USLE) model based on GIS and RS. Along the different levels of roads classified as trunk, county, town, village and unpaved road, the buffer zones were subdivided into five stripes, each of which was 200 meters wide. The average soil erosion modulus of each buffer zone was also counted. Results show that the soil loss decreases with increasing distance to the road except rare trunk roads in the region. In addition, the declined intensity varies with the different levels of roads. Soil erosion was more serious along the lower level road than the higher ones. And soil erosion was more severe for all levels of roads in 1987 than those in 2004 because much more rainfalls affected the situation of soil erosion in 1987.
References | Related Articles | Metrics
Influence of water quality change in Fu River on Wetland Baiyangdian
Ruzhi QIU, Yingxia LI, Zhifeng YANG, Jianghong SHI,
Front. Earth Sci.. 2009, 3 (4): 397-401.  
https://doi.org/10.1007/s11707-009-0056-y

Abstract   PDF (246KB)
Fu River is the only river that has perennial flow into Wetland Baiyangdian and is mainly composed of living sewage and industrial wastewater from Baoding city. Pollutant concentrations were monitored at three sections in the upstream, midstream, and downstream of Fu River and water quality in Wetland Baiyangdian was monitored at seven monitoring sites from 2001 to 2005. Results show that pollutant concentrations in Fu River and pollution load entering Wetland Baiyangdian generally increased during 2001―2005. On average, the concentrations of CODMn and BOD5 increased by 46.5% and 50% from 2001 to 2005 in Fu River and CODMn increased by 17% in Wetland Baiyangdian. The total amount of CODMn and BOD5 entering Wetland Baiyangdian increased from 1630 and 997t/a to 2243 and 1583 tons/year from 2001 to 2005, respectively. Total amount of water within the wetland and non-point source pollution input from surrounding areas also influenced the water quality in the wetland.
References | Related Articles | Metrics
Impact of phased uplift of Tibetan Plateau on environmental changes since late Middle Pleistocene: Palynological records in the three terraces of Middle Shiquan River
Rongke XU, Xiongfei CAI, Yulian ZHANG, Liang SHAN, Yaoyu CHEN, Jianhong QI, Gang WANG,
Front. Earth Sci.. 2009, 3 (4): 402-410.  
https://doi.org/10.1007/s11707-009-0051-3

Abstract   PDF (462KB)
Three fluvial terraces in Porougong River in the middle reach of Shiquan River were identified, and the palynological records were investigated to decipher the paleoenvironmental changes in the west inland of the Tibetan Plateau. Three phases of uplift in the west inland of the Tibetan Plateau are suggested to be associated with the third, second, and first fluvial terraces (T3, T2, and T1) being formed at ca.126―25.1 ka B.P., 25.1―4.5 ka B.P., and 4.5―1.3 ka B.P., respectively. The differentiated uplift rate infers that the inland Tibetan Plateau shows an earlier uplift than the surroundings. Coincident with the phased uplift, three episodes of the changes in paleovegetation and paleoclimate since late Middle Pleistocene could be identified by the spore–pollen records, including the forests under the warm–wet climate featured by the assemblage of Picea + Pinus–Betula–Ulmus–Chenopodiaceae–Epheara in the third terrace, the forest–grassy vegetation under the semi–arid and semi–wet climate as shown by the Picea + Pinus–Chenopodiaceae–Epheara assemblage in the second terrace, and the grassland under the cold–dry climate indicated by the Chenopodiaceae–Artemisia–Ephedra assemblage in the first terrace. The association of the paleovegetation and paleoclimate changes with the phased uplift of the fluvial terraces has revealed the important impact of the Plateau uplift.
References | Related Articles | Metrics
Changes in summer monsoon precipitation over Hunan Province during 1952―2007: response to the west Pacific sea surface temperature and global warming
Jingjing TANG, Hao XU, Zhanghua WANG,
Front. Earth Sci.. 2009, 3 (4): 411-418.  
https://doi.org/10.1007/s11707-009-0063-z

Abstract   PDF (632KB)
Using a historical database (1952―2007) of sea surface temperature (SST) from a subtropical high-controlled area (110°E―140°E, 15°N―35°N) of the west Pacific Ocean and the precipitation over Hunan Province of southeast China, we analyzed time series variations of precipitation in relation to the East Asian summer monsoon and a global warming setting. The results show that there has been a significant increase in SST of the subtropical high-controlled area in the recent 50 years. Although the increase in annual summer monsoon precipitation during the same period has been subtle over Hunan province, seasonal rainfall distribution has obviously changed, represented by a reduction in May, but a significant increase through June to August, especially in July. We suggest that the mechanism of seasonal redistribution of monsoon precipitation is primarily due to the increasing SST that delays the intrusion of the west Pacific Subtropical High, therefore leading to a postponing of migration of the East Asian summer monsoon rainfall belt inland and northward.
References | Related Articles | Metrics
Study on sustainable water use of the Haihe River Basin using ecological network analysis
Yuan LI, Bin CHEN,
Front. Earth Sci.. 2009, 3 (4): 419-430.  
https://doi.org/10.1007/s11707-009-0054-0

Abstract   PDF (328KB)
Sustainable water use of the Haihe River Basin is studied by using the ecological network analysis (ENA) approach. Two related aspects including socioeconomic and environmental water uses sustainability and network organization inherent in system structures are analyzed. For the study of sustainable water use from each single aspect including water use intensity, water use pressure, and environmental protection, a series of new indicators termed as total system throughput water use intensity (TSTUI), total system throughput pressure (TSTP), and environmental flow indicator (EFI) are set up by incorporating parameters of GDP, population, and environmental flow. Based on these three indices, a new integrated index, intensity-pressure-environment (IPE) is established for synthesized measure of sustainable socioeconomic and environmental water uses. The indices of ascendency and overhead are applied for analyzing and characterizing water use network organization. The four subbasins of the Haihe River during 1999–2002, 2005–2007 are studied. The results show that (i) the water use intensity in subbasin II is the best, while that in subbasins I and III are the worst; (ii) subbasin II and subbasins I and III suffer the highest and lowest water use pressure, respectively; (iii) the environmental flow situations in subbasins II and III are the worst and that of subbasin I is the best; (iv) as for the integrated socioeconomic and environmental water uses sustainability, subbasin III is the best, and subbasins I and IV are the worst; (v) the organization level of subbasin I is better than the others’, in which that of subbasin IV is the worst. It can be concluded that the application of ENA in sustainable water use study can provide new angles for water resources management to address the challenges of assessing and optimizing options to obtain more sustainable water use.
References | Related Articles | Metrics
An evaluation on performance of rural eco-environment public expenditure of Chinese local governments : theoretical and empirical analysis
Sheng WANG, Guanghe RAN, Lin WANG, Biao SHI,
Front. Earth Sci.. 2009, 3 (4): 431-436.  
https://doi.org/10.1007/s11707-009-0059-8

Abstract   PDF (85KB)
This paper presents an empirical analysis on Chinese local government rural eco-environment public expenditure performance in 2003―2006 with the method of non-parametric data envelope analysis-malmquist (DEA-Malmquist). The basic conclusion is: first of all, Inner Mongolia, Jiangsu, Zhejiang, Hainan, Tibet, Shanxi, Ningxia and Shanxi, Heilongjiang, Shandong and Gansu are the benchmark units, while Guangdong, Jilin, Liaoning, Guangxi, and Guizhou provinces are far from the frontier and inefficient in fund allocation and management. Secondly, in the entire Chinese local government, the technical efficiency of fiscal support to rural eco-environment investment during 2003/2004 and 2005/2006 was improved and stable, while it degenerated in 2004/2005. Finally, there are 23 provinces in China that have growing and stable technical efficiencies in rural eco-environment public expenditure.
References | Related Articles | Metrics
Pollution in Taihu Lake, China: causal chain and policy options analyses
Liang WANG, Yongli CAI, Liyan FANG,
Front. Earth Sci.. 2009, 3 (4): 437-444.  
https://doi.org/10.1007/s11707-009-0043-3

Abstract   PDF (268KB)
Taihu Lake is located at the densely populated region of the eastern coast of China. Taihu Basin is one of the most developed regions of China. Over the past decades, especially since the reforming and opening-up of China in 1980s, the lake has received more and more pressure from a variety of interlinked human activities, including industrial pollution, fertilizer and pesticide application, eutrophication, overfishing, etc. Water quality has been deteriorating sharply in the lake. In this paper,we made a comprehensive assessment of the environmental and socio-economic issues to affect Taihu Lake ecosystem health. Pollution was identified as the most serious environmental concern. The root causes of these environmental problems are recognized to be diverse, including dense population, high urbanization, heavy industrialization, fast economic development, insufficient sewage treatment, weak public awareness of environment conservation, and lack of institutional capacity and insufficient enforcement through regulations and legislation. On the policy part, past and current policies and measures are reviewed, especially the “Zero” discharge action and phosphate ban in detergents in Taihu Basin. In order to mitigate environmental problems, some further policy options have been proposed, including: improving the fishery management; strengthening cross- provincial collaboration; making efforts to reduce flood disaster and increasing investment to new environmental protection technologies. It is important to assess the economic, social and environmental values of natural resources (soil, water and organisms) in order to allocate them efficiently and fairly between the present and future generations.
References | Related Articles | Metrics
n -alkanol ratios as proxies of paleovegetation and paleoclimate in a peat-lacustrine core in southern China since the last deglaciation
Yanhong ZHENG, Shucheng XIE, Xiaomin LIU, Weijian ZHOU, Philip A. MEYERS,
Front. Earth Sci.. 2009, 3 (4): 445-451.  
https://doi.org/10.1007/s11707-009-0052-2

Abstract   PDF (212KB)
High resolution records of long chain n-alkanol biomarkers were obtained from a peat-lacustrine core from the Dingnan profile in southern China. The n-alkanol distributions are characterized by the predominance of even-over-odd carbon number and maximize at C24 or C26. On the basis of the reported n-alkanol records in the literature and the n-alkane record in our samples, we concluded that the n-alkanol ratio of C26/C30 varying from 1.25 to 6.48, together with the n-alkanol ratio C22/C24 less than unity, is indicative of the presence of a dominant forest paleovegetation. A 2000-year cycling in the variation of the n-alkanol ratio C26/C30 is identifiable in our profile, and probably results from the change in the abundance of the grass relative to trees induced by a cyclic paleoclimate. The n-alkanol ratio C24/C26 appears to be more sensitive to change in precipitation than in temperature, and may be a potential indicator of precipitation/humidity, with increased values being associated with relatively dry conditions. The paleovegetation and the paleoclimate reconstructed on the basis of the n-alkanol records for the recent 18000 cal a BP in general accord with the pollen data and other lipid evidence recorded in the Dingnan region in southern China. In particular, both the n-alkanol records and the pollen data infer the different paleoclimate conditions for the two peat sequences, with a cool and wet climate dominating in the lower peat deposition formed during the latest Pleistocene and a change to a drier and cooler climate occurring in the upper peat sequence in mid-Holocene.
References | Related Articles | Metrics
Paleofire indicated by triterpenes and charcoal in a culture bed in eastern Kunlun Mountain, Northwest China
Dan JIAO, Huan YANG, Xinjun WANG, Shucheng XIE, Shuyuan XIANG,
Front. Earth Sci.. 2009, 3 (4): 452-456.  
https://doi.org/10.1007/s11707-009-0053-1

Abstract   PDF (154KB)
A series of biomarkers were analyzed in the 4000 a B.P. loess sediments in Balong, Dulan County at the north of the eastern Kunlun Mountain in Northwest China using gas chromatography-mass spectrometry. Olean-2,13(18)-ene, olean-2,12-ene, urs-2,12-ene and 5a14a17a20R-stigmasterane identified in an ancient culture bed were observed in association with charcoal grains, believed to be the products of paleofire due to the anthropogenic activity in Qijia culture. These triterpenes were proposed to be derived from dehydration of oleanolic acid and ursolic acid present in angiosperms, and 5a14 a17a20R-stigmasterane was derived from stenols; they both were formed during incomplete combustion. The n-alkane distributions show a shift in the dominant carbon from C27 or C29 to C31, indicative of the abrupt change in paleovegetation from woody to herbaceous plants driven by the changing paleoclimate at 4000 a B.P. after the Holocene Optimum. Coincidently, the Qjijia agriculture culture began to collapse during the 200-year cooling and dryness, and was replaced by nomadism in the mountainous area. The paleofire identified is such a record as to document the change of ancient culture induced by paleoclimate change.
References | Related Articles | Metrics
A numerical study on rapid intensification of Hurricane Charley (2004) near landfall
Kyungjeen PARK, X. ZOU, Gang LI
Front. Earth Sci.. 2009, 3 (4): 457-470.  
https://doi.org/10.1007/s11707-009-0048-y

Abstract   PDF (1106KB)
The rapid intensification of Hurricane Charley (2004) near landfall is studied using the fifth-generation Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Model (MM5) and its adjoint system for both vortex initialization and forecasts. A significant improvement in both track and intensity forecasts is achieved after an ill-defined storm vortex, derived from large-scale analysis, in the initial condition is replaced by the vortex generated by a four-dimensional data variational (4D-Var) hurricane initialization scheme. Results from numerical experiments suggest that both the inclusion of the upper-level trough and the use of high horizontal resolution (6 km) are important for numerical simulations to capture the observed rapid intensification as well as the size reduction during the rapid intensification of Hurricane Charley. The approach of the upper-level trough significantly enhanced the upper-level divergence and vertical motion within simulated hurricanes. Small-scale features that are not resolvable at 18 km resolution are important to the rapid intensification and shrinking of Hurricane Charley (2004). Numerical results from this study further confirm that the theoretical relationship between the intensification and shrinking of tropical cyclones based on the angular momentum conservation and the cyclostrophic approximation can be applied to the azimuthal mean flows.
References | Related Articles | Metrics
Centennial fluctuations of flood-season discharge of Upper and Middle Yangtze River Basin, China (1865―1988): cause and impact
Yonghong DONG, Zhanghua WANG, Zhongyuan CHEN, Daowei YIN,
Front. Earth Sci.. 2009, 3 (4): 471-479.  
https://doi.org/10.1007/s11707-009-0064-y

Abstract   PDF (404KB)
This paper reveals the nature of flood-season discharge and the associated impact on the upper and middle Yangtze river basin, on the basis of a historical database of daily discharges recorded at the Yichang (1865―1985) and Hankou (1878―1988) hydrological stations. Results show the period of discharge fluctuations of 2―6a, which is significant during 1878―1900 and 1915―1975 at Yichang station and the period of 2―7a during 1865―1905 and 1925―1975 at Hankou station. Within these periods, a major period of 2.9―3.5a and two secondary periods of 7―8a and 13.9―16.5a can be further identified from both stations. Our observation verifies that the fluctuations of streamflows of the upper and middle Yangtze River are fairly consistent with the periodicities of the Asia monsoon precipitation and ENSO event, reflecting coupling effect on the fluctuations of discharges in the Yangtze basin. In the 1920s―1960s, intensified variability of streamflows of the upper and middle Yangtze River was closely associated with warming temperature in the basin and in China as well. In 1975―1988, insignificant discharge fluctuations recorded at both stations can be chiefly attributed to human activities, i.e., the large number of reservoirs constructed and associated increasing capacity of water storage, which has largely weakened the discharge fluctuations throughout the basin.
References | Related Articles | Metrics
Thin layer molecularly imprinted composite membranes for selective separation of erythromycin from water
Jinyang YU, Xiaoling HU, Dapeng LI, Cuicui JIAO,
Front. Earth Sci.. 2009, 3 (4): 480-489.  
https://doi.org/10.1007/s11707-009-0055-z

Abstract   PDF (396KB)
Molecularly imprinted composite membranes for selective binding of erythromycin were synthesized by UV initiated photo-copolymerization using polysulfone ultrafiltration (PSF) membranes as porous supports. The thin imprinted layers deposited on the surface of the support membranes were formed by copolymerization of acrylic acid (AA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker in the presence of erythromycin as template molecule in acetonitrile solution. Fourier transform infrared spectroscopy (FT-IR) was used to study the binding mechanism between the imprinted sites and the template. Scanning electron microscope (SEM) was utilized to visualize surface and cross-sections of membranes to gain better understanding in the analysis of imprinted layers deposited on PSF support membranes. The modification degrees for imprinted and nonimprinted membranes are 2.04 and 2.15mg/cm2, respectively. Static equilibrium binding and recognition properties of the imprinted and nonimprinted membranes to erythromycin (EM) and its analogue roxithromycin (RM) in aqueous system were tested. The results showed that saturated binding capacity of imprinted membranes to erythromycin was about 0.185mg/cm2, nearly eight times that of nonimprinted ones, and the selectivity factor of αEM/RM was 3.24. The results of this study implied that the synthesized molecularly imprinted composite membranes could be used as selective separation materials for erythromycin enrichment from water.
References | Related Articles | Metrics
Relationship between soil physiochemistry and land degradation in the lower Heihe River basin of northwestern China
Qi FENG, Haiyang XI, Wei LIU,
Front. Earth Sci.. 2009, 3 (4): 490-499.  
https://doi.org/10.1007/s11707-009-0061-1

Abstract   PDF (222KB)
Monitoring of soil-water physiochemistry (pH, total salt content, ion types, and ion ratios) across the lower Heihe River basin of northwestern China indicated that the distribution of different soil hydrochemical types typically correlated with that of different levels of soil desertification, specifically: 1) lands with the potential for desertification showed a "Graphic" soil-water ion complement, 2) those under on-going desertification a "Graphic" ion complement, 3) those under severe desertification a "Graphic" ion complement, and 4) those under very severe desertification a "Graphic" ion complement. The total soil N, P, and K, pH and organic matter of desertified lands tend to be relatively spatially concentrated, whereas available N, P and K are scattered. Based on an analysis of the main nutrients, the cumulative percent contribution of total N, total P, organic matter, and available N reached 76.24% of ecosystem needs and basically reflect the level of soil fertility. According to a low-dimensional cluster analysis of principal components and the differentiation and alikeness of integrated nutrient gradients, the soils in the study region were classified into four types, which coincided spatially with the four desertification land types. With a decrease in the quantity of water exiting the upper and middle reaches of the Heihe River basin, the salinity of surface waters and shallow water table depth (WTD) in the lower reaches have significantly increased through evaporation. The changes in the hydrological process have caused an imbalance in water distribution across the basin, and altered the state of oasis-supporting water resources. The deterioration of soil water and expansion of desertification progress from non-salinized soils in the oasis, to soils slightly salinized through periodic salt accumulation, salinized Chao soils, and salinized forest shrub meadow soils along the riverbanks and on lake shores. These can then evolve into moderately to heavily salinized soils and eventually into alkali lands. All together, these degradative processes constitute the complex dynamics of oasis desertification, whereby the natural oases’ surface biotic productivity system is degraded, leading to oasis shrinkage, ecosystem deterioration, and land desertification. Consequently, there is an urgent need to extend the study of soil and surface water chemistry in the region.
References | Related Articles | Metrics
14 articles