Responses of Surface Runoff to Climate Change and Human Activities in the Arid Region of Central Asia: A Case Study in the Tarim River Basin, China

NASA Astrophysics Data System (ADS)

Xu, Changchun; Chen, Yaning; Chen, Yapeng; Zhao, Ruifeng; Ding, Hui

2013-04-01

Based on hydrological and climatic data and land use/cover change data covering the period from 1957 to 2009, this paper investigates the hydrological responses to climate change and to human activities in the arid Tarim River basin (TRB). The results show that the surface runoff of three headstreams (Aksu River, Yarkant River and Hotan River) of the Tarim River exhibited a significant increasing trend since 1960s and entered an even higher-runoff stage in 1994. In the contrary, the surface runoff of Tarim mainstream displayed a persistent decreasing trend since 1960s. The increasing trend of surface runoff in the headstreams can be attributed to the combined effects of both temperature and precipitation changes during the past five decades. But, the decreasing trend of surface runoff in the mainstream and the observed alterations of the temporal and spatial distribution patterns were mainly due to the adverse impacts of human activities. Specifically, increasingly intensified water consumption for irrigation and the associated massive constructions of water conservancy projects were responsible for the decreasing trend of runoff in the mainstream. And, the decreasing trend has been severely jeopardizing the ecological security in the lower reaches. It is now unequivocally clear that water-use conflicts among different sectors and water-use competitions between upper and lower reaches are approaching to dangerous levels in TRB that is thus crying for implementing an integrated river basin management scheme.

Responses of surface runoff to climate change and human activities in the arid region of central Asia: a case study in the Tarim River basin, China.

PubMed

Xu, Changchun; Chen, Yaning; Chen, Yapeng; Zhao, Ruifeng; Ding, Hui

2013-04-01

Based on hydrological and climatic data and land use/cover change data covering the period from 1957 to 2009, this paper investigates the hydrological responses to climate change and to human activities in the arid Tarim River basin (TRB). The results show that the surface runoff of three headstreams (Aksu River, Yarkant River and Hotan River) of the Tarim River exhibited a significant increasing trend since 1960s and entered an even higher-runoff stage in 1994. In the contrary, the surface runoff of Tarim mainstream displayed a persistent decreasing trend since 1960s. The increasing trend of surface runoff in the headstreams can be attributed to the combined effects of both temperature and precipitation changes during the past five decades. But, the decreasing trend of surface runoff in the mainstream and the observed alterations of the temporal and spatial distribution patterns were mainly due to the adverse impacts of human activities. Specifically, increasingly intensified water consumption for irrigation and the associated massive constructions of water conservancy projects were responsible for the decreasing trend of runoff in the mainstream. And, the decreasing trend has been severely jeopardizing the ecological security in the lower reaches. It is now unequivocally clear that water-use conflicts among different sectors and water-use competitions between upper and lower reaches are approaching to dangerous levels in TRB that is thus crying for implementing an integrated river basin management scheme.

A coupled modeling framework of the co-evolution of humans and water: case study of Tarim River Basin, western China

NASA Astrophysics Data System (ADS)

Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.

2014-04-01

The complex interactions and feedbacks between humans and water are very essential issues but are poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable to improve our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simple coupled modeling framework for socio-hydrology co-evolution is developed for the Tarim River Basin in Western China, and is used to illustrate the explanatory power of such a model. The study area is the mainstream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four parts, i.e. social sub-system, economic sub-system, ecological sub-system, and hydrological sub-system. In each modeling unit, four coupled ordinary differential equations are used to simulate the dynamics of the social sub-system represented by human population, the economic sub-system represented by irrigated crop area, the ecological sub-system represented by natural vegetation cover and the hydrological sub-system represented by stream discharge. The coupling and feedback processes of the four dominant sub-systems (and correspondingly four state variables) are integrated into several internal system characteristics interactively and jointly determined by themselves and by other coupled systems. For example, the stream discharge is coupled to the irrigated crop area by the colonization rate and mortality rate of the irrigated crop area in the upper reach and the irrigated area is coupled to stream discharge through irrigation water consumption. In a similar way, the stream discharge and natural vegetation cover are coupled together. The irrigated crop area is coupled to human population by the colonization rate and mortality rate of the population. The inflow of the lower reach is

A conceptual socio-hydrological model of the co-evolution of humans and water: case study of the Tarim River basin, western China

NASA Astrophysics Data System (ADS)

Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.

2015-02-01

The complex interactions and feedbacks between humans and water are critically important issues but remain poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable for improving our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simplified conceptual socio-hydrological model based on logistic growth curves is developed for the Tarim River basin in western China and is used to illustrate the explanatory power of such a co-evolutionary model. The study area is the main stream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four sub-systems, i.e., the hydrological, ecological, economic, and social sub-systems. In each modeling unit, the hydrological equation focusing on water balance is coupled to the other three evolutionary equations to represent the dynamics of the social sub-system (denoted by population), the economic sub-system (denoted by irrigated crop area ratio), and the ecological sub-system (denoted by natural vegetation cover), each of which is expressed in terms of a logistic growth curve. Four feedback loops are identified to represent the complex interactions among different sub-systems and different spatial units, of which two are inner loops occurring within each separate unit and the other two are outer loops linking the two modeling units. The feedback mechanisms are incorporated into the constitutive relations for model parameters, i.e., the colonization and mortality rates in the logistic growth curves that are jointly determined by the state variables of all sub-systems. The co-evolution of the Tarim socio-hydrological system is then analyzed with this conceptual model to gain insights into the overall system dynamics and its sensitivity to the

Estimating terrestrial water storage changes in the Tarim River Basin using GRACE data

NASA Astrophysics Data System (ADS)

Zhao, Kefei; Li, Xia

2017-12-01

Terrestrial water storage (TWS) plays a fundamental role in the arid Tarim River Basin, which is mainly fed by glacier and snow melt water. However, the significant scarcity of ground-based observations, especially in the high-altitude mountain areas, limits our understanding of TWS changes in this region. In this study, TWS variations in the Tarim River Basin were estimated using monthly GRACE Level 2 Release 5 (RL05) products from 2002 to August 2015. The GRACE results were validated against outputs of Global Land Data Assimilation System (GLDAS) including spatial and temporal correlation analysis. The correlation between the regional TWS time-series of GRACE and GLDAS is 0.7777. It was found that GRACE TWS shows a slightly decreasing trend of -1.4069 ± 0.5060 mm yr-1 in the entire Tarim River Basin during the study period and a significant spatial difference over the study area. An apparent decreasing trend in Tien Shan and the Taklamakan Desert, and a significant increasing trend in the Kunlun Mountains and eastern Pamirs Plateau were also detected. Moreover, seasonal analysis of regional TWS time-series, precipitation and the 0 °C isotherm height in summer showed that detrended TWS variations were consistent with precipitation while long-term trends of TWS were contrary to that of the 0 °C isotherm height in summer. It implied that the interannual TWS variations were dominated by precipitation and the long-term trend of TWS changes was affected by changes of the 0 °C isotherm height in summer. This information could enrich our knowledge about water storage changes, including glacier mass balance and groundwater, and its response to climate change in this vast but sparse in-situ measurements area.

Multiple cooling episodes in the Central Tarim (Northwest China) revealed by apatite fission track analysis and vitrinite reflectance data

NASA Astrophysics Data System (ADS)

Chang, Jian; Qiu, Nansheng; Song, Xinying; Li, Huili

2016-06-01

Apatite fission track and vitrinite reflectance are integrated for the first time to study the cooling history in the Central Tarim, northwest China. The paleo-temperature profiles from vitrinite reflectance data of the Z1 and Z11 wells showed a linear relationship with depth, suggesting an approximately 24.8 °C/km paleo-geothermal gradient and 2700-3900 m of erosion during the Early Mesozoic. The measured apatite fission track ages from well Z2 in the Central Tarim range from 39 to 159 Ma and effectively record the Meso-Cenozoic cooling events that occurred in Central Tarim. Moreover, two cooling events at 190-140 Ma in the Early Jurassic-Early Cretaceous and 80-45 Ma in the Late Cretaceous-Paleocene revealed by measured AFT data and thermal modeling results are related to the collisions of the Qiangtang-Lhasa terranes and the Greater India Plate with the southern margin of the Eurasian Plate, respectively. This study provides new insights into the tectonic evolution of the Tarim Basin (and more broadly Central Asia) and for hydrocarbon generation and exploration in the Central Tarim.

Analysis of water use strategies of the desert riparian forest plant community in inland rivers of two arid regions in northwestern China

NASA Astrophysics Data System (ADS)

Chen, Y. N.; Li, W. H.; Zhou, H. H.; Chen, Y. P.; Hao, X. M.; Fu, A. H.; Ma, J. X.

2014-10-01

Studies of the water use of the desert riparian forest plant community in arid regions and analyses of the response and adaptive strategies of plants to environmental stress are of great significance to the formulation of effective ecological conservation and restoration strategies. Taking two inland rivers in the arid regions of northwestern China, downstream of the Tarim River and Heihe River Basin as the research target regions, this paper explored the stem water potential, sap flow, root hydraulic lift, and characteristics of plant water sources of the major constructive species in the desert riparian forest, Populus euphratica and Tamarix ramosissima. Specifically, this was accomplished by combining the monitoring of field physiological and ecological indicators, and the analysis of laboratory tests. Then, the water use differences of species in different ecological environments and their ecological significance were analyzed. This study indicated that: (1) in terms of water sources, Populus euphratica and Tamarix ramosissima mainly used deep subsoil water and underground water, but the plant root system in the downstream of the Tarim River was more diversified than that in the downstream of the Heihe River in water absorption, (2) in terms of water distribution, Populus euphratica root possessed hydraulic lift capacity, but Populus euphratica root in the downstream of the Tarim River presented stronger hydraulic lift capacity and more significant ecological effect of water redistribution, (3) in terms of water transport, the plants in the downstream of the Heihe River can adapt to the environment through the current limiting of branch xylem, while plants in the downstream of the Tarim River substantially increased the survival probability of the whole plant by sacrificing weak branches and improving the water acquisition capacity of dominant branches; and (4) in terms of water dissipation, the water use and consumption of Populus euphratica at night exhibited

Paleomagnetism and tectonics of the Southern Tarim Basin, northwestern China

NASA Astrophysics Data System (ADS)

Gilder, Stuart; Zhao, Xixi; Coe, Robert; Meng, Zifang; Courtillot, Vincent; Besse, Jean

1996-10-01

We report Late Carboniferous, Permian, and early Tertiary paleomagnetic data from the southern Tarim basin. Prefolding magnetizations were isolated in each case. The Late Carboniferous-Permian and early Tertiary poles lie at 64.6°N, 166.5°E, A95 = 6.3° and 58.1°N, 202.0°E, A95 = 12.7°, respectively. The Late Jurassic to early Tertiary (J3-E1) paleolatitudes of Tarim and several basins throughout central Asia are similar, yet significantly (10° to 20°) shallower than those predicted by the Eurasian apparent polar wander path. Resolving this discrepancy remains a major problem in Asian paleomagnetism. Discordance of the late Paleozoic poles from Tarim and Siberia suggest that Tarim has rotated about 30° counterclockwise with respect to Siberia since the Permian. Where paleomagnetic samples of both Late Carboniferous to Early Triassic (C3-T1) and J3-E1 ages were collected from the same area of Tarim, a great circle passes through the means of the poles and the sampling locality. This suggests that (1) only a difference in inclination (and not declination) distinguishes the two data sets, and (2) vertical axis block rotations of the C3-E1 strata occurred after E1. Although based on data of lesser quality, the mean Early to Middle Jurassic (J1-2) pole from Tarim differs significantly from the Eurasian reference pole, requiring radical tectonic solutions to resolve them. The Tarim J1-2 pole is indistinguishable from both the mean J3-E1 and C3-T1 poles. The similarity of all the poles and the analogous tectonic setting of present-day central Asia to that of the late Paleozoic in eastern North America raises the question whether all the data from Tarim are overprinted.

Stability and tilting of regional water cycle over Tarim Basin

NASA Astrophysics Data System (ADS)

Zhang, Hongquan; Ma, Zhuguo

2018-06-01

The Tarim Basin is located upwind of the Gobi Desert where individual deserts have expanded significantly during the last 50 years. In recent history, stable runoff in the Tarim Basin has been observed despite the Lop Nur dry up and dramatic water consumption shift from east to west. This regional water cycle stability is conceptually explained based on the relationship between precipitation and evapotranspiration. The water consumption imbalance is caused by human activities near the river sources, which tilts the humidity profile over the basin. As a result, more water vapour spills from the western part of the basin and causes precipitation to increase in adjacent areas. At the same time, the Westerlies carry the low humidity air mass out of the eastern part of the basin to make the downwind Gobi Desert and surrounding areas drier. Therefore, the observed wetting on the west and drying on the east of northwest China are coupled.

Quantile regression and clustering analysis of standardized precipitation index in the Tarim River Basin, Xinjiang, China

NASA Astrophysics Data System (ADS)

Yang, Peng; Xia, Jun; Zhang, Yongyong; Han, Jian; Wu, Xia

2017-11-01

Because drought is a very common and widespread natural disaster, it has attracted a great deal of academic interest. Based on 12-month time scale standardized precipitation indices (SPI12) calculated from precipitation data recorded between 1960 and 2015 at 22 weather stations in the Tarim River Basin (TRB), this study aims to identify the trends of SPI and drought duration, severity, and frequency at various quantiles and to perform cluster analysis of drought events in the TRB. The results indicated that (1) both precipitation and temperature at most stations in the TRB exhibited significant positive trends during 1960-2015; (2) multiple scales of SPIs changed significantly around 1986; (3) based on quantile regression analysis of temporal drought changes, the positive SPI slopes indicated less severe and less frequent droughts at lower quantiles, but clear variation was detected in the drought frequency; and (4) significantly different trends were found in drought frequency probably between severe droughts and drought frequency.

Heat flow, deep formation temperature and thermal structure of the Tarim Basin, northwest China

NASA Astrophysics Data System (ADS)

Liu, Shaowen; Lei, Xiao; Feng, Changge; Li, Xianglan

2016-04-01

Geothermal regime of a sedimentary basin not only provides constraint on understanding the basin formation and evolution, but also offers fundamental parameters for hydrocarbon resources assessment. As one of three Precambrian blocks in China, the Tarim craton is also a current hydrocarbon exploration target where the largest sedimentary basin (Tarim Basin) develops with great potential. Although considerable advancement of geothermal regime of this basin has been made during the past decades, nearly all the temperature data in previous studies are from the exploration borehole formation testing temperatures. Recently, we have conducted the steady-state temperature logging in the Tarim basin, and measured abundant rock thermal properties, enabling us to re-visit the thermal regime of this area with more confidence. Our results show that the present-day geothermal gradients for the Tarim Basin vary from 23 K/km to 27 K/km, with a mean of 22 K/km; the values of heat flow range from 40 mW/m2 to 49 mW/m2, with a mean of 43 mW/m2. These new data confirmed that the Tarim Basin has relatively low heat flow and shares similar geothermal regime with other Precambrian cratons in the world. In addition, the new temperatures from the steady-state logs are larger than the bottom hole temperatures (BHT) as 22 degree Celsius, indicating the thermal non-equilibrium for the BHTs used in previous studies. Spatial distribution of the estimated formation temperatures-at-depth of 1~5km within the basin is similar and mainly controlled by crystalline basement pattern. Generally, the temperatures at the depth of 1km range from 29 to 41 degree Celsius, with a mean of 35 degree Celsius; while the temperatures at 3km vary from 63 to 100 degree Celsius, and the mean is 82 degree Celsius; at 5km below the surface, the temperatures fall into a range between 90 and 160 degree Celsius, with a mean of 129 degree Celsius. We further proposed the long-term low geothermal background and large burial

Neoproterozoic paleogeography of the Tarim Block: An extended or alternative "missing-link" model for Rodinia?

NASA Astrophysics Data System (ADS)

Wen, Bin; Evans, David A. D.; Li, Yong-Xiang

2017-01-01

Recent reconstructions of the Rodinia supercontinent and its breakup incorporate South China as a "missing link" between Australia and Laurentia, and place the Tarim craton adjacent to northwestern Australia on the supercontinent's periphery. However, subsequent kinematic evolution toward Gondwana amalgamation requires complex geometric shuffling between South China and Tarim, which cannot be easily resolved with the stratigraphic records of those blocks. Here we present new paleomagnetic data from early Ediacaran strata of northwest Tarim, and document large-scale rotation at near-constant paleolatitudes during Cryogenian time. The rotation is coeval with Rodinia breakup, and Tarim's paleolatitudes are compatible with its placement between Australia and Laurentia, either by itself as an alternative "missing link" or joined with South China in that role. At the same time, indications of subduction-related magmatism in Tarim's Neoproterozoic record suggest that Rodinia breakup was dynamically linked to subduction retreat along its northern margin. Such a model is akin to early stages of Jurassic fragmentation within southern Gondwana, and implies more complicated subduction-related dynamics of supercontinent breakup than superplume impingement alone.

Geothermal regime of Tarim basin, NW China: insights from borehole temperature logging

NASA Astrophysics Data System (ADS)

Liu, S.; Lei, X.

2013-12-01

Geothermal regime of sedimentary basin is vital for understanding basin (de)formation process, hydrocarbon generation status and assessing the resource potential. Located at the Precambrian craton block, the Tarim basin is the largest intermountain basin in China, which is also the ongoing target of oil and gas exploration. Previous knowledge of thermal regime of this basin is from limited oil exploration borehole testing temperature, the inherent deficiency of data of this type makes accurate understanding of its thermal regime impossible. Here we reported our latest steady temperature logging results in this basin and analyze its thermal regime as well. In this study, 10 temperature loggings are conducted in the northern Tarim basin where the major oil and gas fields are discovered. All the boreholes for temperature logging are non-production wells and are shut in at least more than 2~3 years, ensuring the temperature equilibrium after drilling. The derived geothermal gradient varies from 20.2 to 26.1 degree/km, with a mean of 22.0 degree/km. However, some previous reported gradients in this area are obviously lower than our results; for example, the previous gradient of THN2 well is 13.2 degree/km but 23.2 degree/km in this study, and not enough equilibrium time in previous logging accounts for this discrepancy. More important, it is found that high gradients usually occur in the gas field and the gradients of the gas fields are larger than those in other oil fields, indicating higher thermal regime in gas field. The cause of this phenomenon is unclear, and the upward migration of hot fluid along fault conduit is speculated as the possible mechanism for this high geothermal anomaly in the oil and gas fields. Combined with measured thermal conductivity data, 10 new heat flow values are also achieved, and the heat flow of the Tarim basin is between 38mW/m2 and 52mW/m2, with a mean of 43 mW/m2. This relatively low heat flow is coincident with that of typical

Estimate of subsurface formation temperature in the Tarim basin, northwest China

NASA Astrophysics Data System (ADS)

Liu, Shaowen; Lei, Xiao; Feng, Changge; Hao, Chunyan

2015-04-01

Subsurface formation temperature in the Tarim basin, the largest sedimentary basin in China, is significant for its hydrocarbon generation, preservation and geothermal energy potential assessment, but till now is not well understood, due to poor data coverage and a lack of highly accurate temperature data. Here, we combined recently acquired steady-state temperature logging data, drill stem test temperature data and measured rock thermal properties, to investigate the geothermal regime, and estimate the formation temperature at specific depths in the range 1000~5000 m in this basin. Results show that the heat flow of the Tarim basin ranges between 26.2 and 66.1 mW/m2, with a mean of 42.5±7.6 mW/m2; geothermal gradient at the depth of 3000 m varies from 14.9 to 30.2 °C/km, with a mean of 20.7±2.9 °C/km. Formation temperature at the depth of 1000 m is estimated to be between 29 °C and 41°C, with a mean of 35°C; whilst the temperature at 2000 m ranges from 46~71°C with an average of 59°C; 63~100°C is for that at the depth of 3000 m, and the mean is 82°C; the temperature at 4000 m varies from 80 to 130°C, with a mean of 105°C; 97~160°C is for the temperature at 5000 m depth. In addition, the general pattern of the subsurface formation temperatures at different depths is basically similar and is characterized by high temperatures in the uplift areas and low temperatures in the sags. Basement structure and lateral variations in thermal properties account for this pattern of the geo-temperature field in the Tarim basin.

[Spatiotemporal variation of Populus euphratica's radial increment at lower reaches of Tarim River after ecological water transfer].

PubMed

An, Hong-Yan; Xu, Hai-Liang; Ye, Mao; Yu, Pu-Ji; Gong, Jun-Jun

2011-01-01

Taking the Populus euphratica at lower reaches of Tarim River as test object, and by the methods of tree dendrohydrology, this paper studied the spatiotemporal variation of P. euphratic' s branch radial increment after ecological water transfer. There was a significant difference in the mean radial increment before and after ecological water transfer. The radial increment after the eco-water transfer was increased by 125%, compared with that before the water transfer. During the period of ecological water transfer, the radial increment was increased with increasing water transfer quantity, and there was a positive correlation between the annual radial increment and the total water transfer quantity (R2 = 0.394), suggesting that the radial increment of P. euphratica could be taken as the performance indicator of ecological water transfer. After the ecological water transfer, the radial increment changed greatly with the distance to the River, i.e. , decreased significantly along with the increasing distance to the River (P = 0.007). The P. euphratic' s branch radial increment also differed with stream segment (P = 0.017 ), i.e. , the closer to the head-water point (Daxihaizi Reservoir), the greater the branch radial increment. It was considered that the limited effect of the current ecological water transfer could scarcely change the continually deteriorating situation of the lower reaches of Tarim River.

Comparison of Tarim and central Asian FSU basins, I: Phanerozoic paleogeography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heubeck, C.; Shangyou N.

1996-12-31

Large amounts of previously unpublished data on the petroleum geology of the FSU`s Central Asian Republics and of China`s Tarim region have found their way into the western public domain in the past few years. These data provide for the first time the opportunity to merge detailed stratigraphic, tectonic, and paleogeographic studies done during the past decades on both sides of the FSU-Chinese border and to place the results in a plate-tectonic and palinspastically restored reference frame. Major tectonic events affecting the active post-Silurian south-facing margin of Asia between the Caspian Sea and Tarim include (1) the collapse of themore » Kazakhstan arc fragments (ca. 400-300 Ma); (2) collision of YiIi with Tarim (ca. 375 Ma); (3) consolidation of the Turan Platform from pre-existing basement blocks (ca. 280-220 Ma), (4) collision of Tarim/Yili with the Kazakhstan arcs (ca. 260 Ma); (5) stabilization of a south-facing Triassic active margin (ca. 250 - 200 Ma); (6) accretion of Cimmeria (ca. 200 Ma) and associated reactivation events in Turan, Syr-Darja, and Tarim; (7) reactivation and modification of intracontinental structures during the collision of central Asia with India (ca. 55 Ma to present) and with the Arabian platform (ca. 25 Ma). Periodic large-scale flooding of denuded continental platforms (Turan, Tadjik) during sea-level highstands is recorded in the Jurassic, Mid-Late Cretaceous, and the Early Tertiary, resulting in extensive tracts of restricted marine sedimentary systems and marine incursions deep into central Asia (SW Tarim, Kuche Depression, Fergana, Turgay). Mesozoic-Cenozoic source rocks are sensitive to rapid lateral facies changes, and understanding their distribution requires detailed stratigraphic analysis. The attempted synthesis of data from China and the FSU with plate-tectonic concepts allows the transfer and testing of play concepts and hydrocarbons systems across the FSU-Chinese border.« less

Paleoclimatic and paleomagnetic constraints on the Paleozoic reconstructions of south China, north China and Tarim

NASA Astrophysics Data System (ADS)

Shangyou, Nie

1991-10-01

Paleomagnetic and paleoclimatic data provide the most useful latitudinal constraints for plate reconstructions. Distributions through the Paleozoic of five types of climatically sensitive sediments (coals, evaporites, reefs, dolomites and limestones) for south China, north China and Tarim are shown on 15 maps that include 1578 reliable data points. These paleoclimatic data agree reasonably well with available paleomagnetic directions, although significant divergence between the two exists for the Early Paleozoic. These data indicate the following: (1) South China was in low latitudes during the entire Paleozoic, with a subtropical position in the Cambrian. (2) North China also remained near the equator in the Early and Late Paleozoic, except for the Ordovian and the Late Permian when extensive evaporites suggest slightly higher latitudinal positions, while its Middle Paleozoic position is uncertain due to the missing stratigraphie record. (3) In south China, local tectonics appears to have played a dominant role in determining paleogeography and therefore marine sedimentation, especially after the Late Ordovician-Early Silurian, because the areal coverage of marine sediments through time is distinctly different from what would be expected from published global sea-level curves. (4) Paleoclimatic and paleomagnetic data are compatible with biogeographic data which suggest that south China was part of eastern Gondwana in the Early Paleozoic, but was widely separated from Gondwana in the Late Paleozoic, and the split between the two probably happened in the Devonian, giving rise to a major break-up unconformity in central south China.

[Correlationships between the coverage of vegetation and the quality of groundwater in the lower reaches of the Tarim River].

PubMed

Chen, Yong-jin; Chen, Ya-ning; Liu, Jia-zhen

2010-03-01

The variations vegetation coverage is the result of conjunct effects of inner and outer energy of the earth, however, the human activity always makes the coverage of vegetation change a lot. Based on the monitoring data of chemistry of groundwater and the coverage of vegetation from 2002 to 2007 in the lower reaches of Tarim River, relations between vegetation coverage and groundwater chemistry were studied. It is found that vegetation coverage at Sector A was more than 80%, and decreased from sector to sector, the coverage of Sector I was less than 10%. At the same sector, samples near to water source owned high coverage index, and samples far away from the river had low coverage index. The variations of pH in groundwater expressed similar regulation to vegetation coverage, that is, Sectors near the water source had higher pH index comparing than those far away. Regression between groundwater quality and vegetation coverage disclosed that the coverage of Populus euphratica climbed up along with increase of pH in groundwater, change of Tamarix ramosissima coverage expressed an opposite trend to the Populus euphratica with the same environmental factors. This phenomenon can interpret spatial distribution of Populus euphratica and Tamarix ramosissima in lower reaches of the Tarim River.

Recognized Multiple Rifts of the Neoproterozoic in the Initiation of the Tarim Craton (NW China) and Their Tectonic Implications

NASA Astrophysics Data System (ADS)

He, B.; Jiao, C.; Huang, T.; Zhou, X.; Cai, Z.; Cao, Z.; Jiang, Z.; Cui, J.; Yu, Z.; Chen, W.

2017-12-01

The Tarim Basin is the largest, oil-bearing and superimposed basin in the northwest of China. The development and tectonic property of the initial Tarim basin have been acutely disputed and remain enigmatic. Urgently need to reveal the origin and formation dynamics of the Tarim Carton and evaluate the potential of the deep energy resources. However, covered by vast desert and huge-thickness sedimentary strata, suffered by multiple tectonic movements, seismic data with low signal- to- noise ratio in the deep are the critical difficulties. We analyse 4 field outcrops, 18 wells, 27 reprocessed seismic reflection profiles with high SNR across the basin and many ancillary ones and aeromagnetic data. We find about 20 normal fault-controlled rift depressions of the Cryogenian and Ediacaran scattered in the Tarim basin, which developed on the Precambrian metamorphic and crystalline basements and covered by the epeiric sea and basin facies sediments of the Lower Cambrian. The structural styles of the rifts are mainly half grabens, symmetrical troughs and horst-grabens. The regional differences exist obviously in spatial and temporal. The WNW-ESE-trending faults occur in the central part and northern of the basin and the NE, and the NEE-trending faults occur in the southern parts, which response with the anomaly of aeromagnetic. Some main faults of the Ediacaran inherited from the Cryogenian and some occurred newly, the more rifting depressions occurred during the Ediacaran. The extensional NNW-SSE-oriented and NNE-SSW-oriented paleostress field occurred simultaneously during rifting, and accompanied with the clockwise shearing. According to the activities of syn-sedimentary faults, magmatic events and sediments, the tectonic properties of the rifts are different depending on their locations in the Tarim craton. The rifting phases mainly occurred from 780 Ma to 615 Ma. The formation of rifts were associated with the opening of the South Tianshan Ocean and the South Altun

Comparison of Tarim and central Asian FSU basins, I: Phanerozoic paleogeography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heubeck, C.; Shangyou N.

1996-01-01

Large amounts of previously unpublished data on the petroleum geology of the FSU's Central Asian Republics and of China's Tarim region have found their way into the western public domain in the past few years. These data provide for the first time the opportunity to merge detailed stratigraphic, tectonic, and paleogeographic studies done during the past decades on both sides of the FSU-Chinese border and to place the results in a plate-tectonic and palinspastically restored reference frame. Major tectonic events affecting the active post-Silurian south-facing margin of Asia between the Caspian Sea and Tarim include (1) the collapse of themore » Kazakhstan arc fragments (ca. 400-300 Ma); (2) collision of YiIi with Tarim (ca. 375 Ma); (3) consolidation of the Turan Platform from pre-existing basement blocks (ca. 280-220 Ma), (4) collision of Tarim/Yili with the Kazakhstan arcs (ca. 260 Ma); (5) stabilization of a south-facing Triassic active margin (ca. 250 - 200 Ma); (6) accretion of Cimmeria (ca. 200 Ma) and associated reactivation events in Turan, Syr-Darja, and Tarim; (7) reactivation and modification of intracontinental structures during the collision of central Asia with India (ca. 55 Ma to present) and with the Arabian platform (ca. 25 Ma). Periodic large-scale flooding of denuded continental platforms (Turan, Tadjik) during sea-level highstands is recorded in the Jurassic, Mid-Late Cretaceous, and the Early Tertiary, resulting in extensive tracts of restricted marine sedimentary systems and marine incursions deep into central Asia (SW Tarim, Kuche Depression, Fergana, Turgay). Mesozoic-Cenozoic source rocks are sensitive to rapid lateral facies changes, and understanding their distribution requires detailed stratigraphic analysis. The attempted synthesis of data from China and the FSU with plate-tectonic concepts allows the transfer and testing of play concepts and hydrocarbons systems across the FSU-Chinese border.« less

Analysis on the adaptive countermeasures to ecological management under changing environment in the Tarim River Basin, China

NASA Astrophysics Data System (ADS)

Yang, Fan; Xue, Lianqing; Zhang, Luochen; Chen, Xinfang; Chi, Yixia

2017-12-01

This article aims to explore the adaptive utilization strategies of flow regime versus traditional practices in the context of climate change and human activities in the arid area. The study presents quantitative analysis of climatic and anthropogenic factors to streamflow alteration in the Tarim River Basin (TRB) using the Budyko method and adaptive utilization strategies to eco-hydrological regime by comparing the applicability between autoregressive moving average model (ARMA) model and combined regression model. Our results suggest that human activities played a dominant role in streamflow deduction in the mainstream with contribution of 120.7%~190.1%. While in the headstreams, climatic variables were the primary determinant of streamflow by 56.5~152.6% of the increase. The comparison revealed that combined regression model performed better than ARMA model with the qualified rate of 80.49~90.24%. Based on the forecasts of streamflow for different purposes, the adaptive utilization scheme of water flow is established from the perspective of time and space. Our study presents an effective water resources scheduling scheme for the ecological environment and provides references for ecological protection and water allocation in the arid area.

Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China

NASA Astrophysics Data System (ADS)

Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan

2017-12-01

The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

Mesozoic non-marine petroleum source rocks determined by palynomorphs in the Tarim Basin, Xinjiang, northwestern China

USGS Publications Warehouse

Jiang, D.-X.; Wang, Y.-D.; Robbins, E.I.; Wei, J.; Tian, N.

2008-01-01

The Tarim Basin in Northwest China hosts petroleum reservoirs of Cambrian, Ordovician, Carboniferous, Triassic, Jurassic, Cretaceous and Tertiary ages. The sedimentary thickness in the basin reaches about 15 km and with an area of 560000 km2, the basin is expected to contain giant oil and gas fields. It is therefore important to determine the ages and depositional environments of the petroleum source rocks. For prospective evaluation and exploration of petroleum, palynological investigations were carried out on 38 crude oil samples collected from 22 petroleum reservoirs in the Tarim Basin and on additionally 56 potential source rock samples from the same basin. In total, 173 species of spores and pollen referred to 80 genera, and 27 species of algae and fungi referred to 16 genera were identified from the non-marine Mesozoic sources. By correlating the palynormorph assemblages in the crude oil samples with those in the potential source rocks, the Triassic and Jurassic petroleum source rocks were identified. Furthermore, the palynofloras in the petroleum provide evidence for interpretation of the depositional environments of the petroleum source rocks. The affinity of the miospores indicates that the petroleum source rocks were formed in swamps in brackish to lacustrine depositional environments under warm and humid climatic conditions. The palynomorphs in the crude oils provide further information about passage and route of petroleum migration, which is significant for interpreting petroleum migration mechanisms. Additionally, the thermal alternation index (TAI) based on miospores indicates that the Triassic and Jurassic deposits in the Tarim Basin are mature petroleum source rocks. ?? Cambridge University Press 2008.

Influence of intermittent water releases on groundwater chemistry at the lower reaches of the Tarim River, China.

PubMed

Chen, Yong-jin; Chen, Ya-ning; Liu, Jia-zhen; Zhang, Er-xun

2009-11-01

Based on the data of the depths and the chemical properties of groundwater, salinity in the soil profile, and the basic information on each delivery of water collected from the years 2000 to 2006, the varied character of groundwater chemistry and related factors were studied. The results confirmed the three stages of the variations in groundwater chemistry influenced by the intermittent water deliveries. The factors that had close relations to the variations in groundwater chemistry were the distances of monitoring wells from the water channel, the depths of the groundwater, water flux in watercourse, and the salinities in soils. The relations between chemical variation and groundwater depths indicated that the water quality was the best with the groundwater varying from 5 to 6 m. In addition, the constructive species in the study area can survive well with the depth of groundwater varying from 5 to 6 m, so the rational depth of groundwater in the lower reaches of the Tarim River should be 5 m or so. The redistribution of salts in the soil profile and its relations to the chemical properties and depths of groundwater revealed the linear water delivery at present combining with surface water supply in proper sections would promote water quality optimized and speed up the pace of ecological restoration in the study area.

[Patterns and characteristics of ecological water demand in west arid zone of China--a case study of green corridor in the lower reaches of Tarim River].

PubMed

Wang, Ranghui; Lu, Xinming; Song, Yudong; Fan, Zili; Ma, Yingjie

2003-04-01

Ecological water demand has some characteristics. The ecological water demand that was used for protection of the green corridor in the lower reaches of Tarim River was chiefly water demand by natural vegetation below Daxihaizi reservoir, and it included gross restoration water amount of ground water level and gross stand water amount in all over the lower reaches of Tarim River. The gross restoration water amount of ground water level mainly included restoration water amount of ground water level and lateral discharge, as well as evaporation of the course. Based on the drainage target of Alagan in 2005, gross ecological water demand was the gross water amount of restoration ground water level between Daxihaizi and Alagan, which would be 13.20 x 10(8) m3. Meanwhile, the annual average water demand would be 2.64 x 10(8) m3. Because the drainage target and vegetation protection target would be all Taitema lake in 2010, the gross ecological water demand included not only the gross water amount of restoration ground water level between Alagan and Taitema lake, but also the ecological stand water amount between Daxihaizi and Taitema lake, which would be 18.32 x 10(8) m3. Meanwhile, the annual average water demand would be 3.66 x 10(8) m3. From the year 2010 to 2030, the gross ecological water demand would be consisted of two parts (the gross stand water amount between Daxihaizi and Alagan, and the water demand by increased vegetation of 18.67 x 10(4) hm2), and the total ecological water demand during the 20 years would be 139.00 x 10(8) m3. Meanwhile, the annual average water demand would be 6.95 x 10(8) m3.

A New age Constraint on Sturtian Glaciation: SHRIMP U-Pb zircon geochronology of Neoproterozoic Altungol Formation in Tarim Basin, NW China

NASA Astrophysics Data System (ADS)

Zhou, X.; Li, J.; Li, W.; Wang, H.

2013-12-01

Neoproterozoic glaciations with a wide distribution, punctuated the largely ice-free Precambrian world within tropical latitudes, interpreted as evidence record the cold paleoclimate intervals which made a Snowball Earth with the frozen ocean. More recently, Quruqtagh of Northeast Tarim Basin, Northwest China, catches the increasing eyes, not only because of its three or four Neoproterzoic glacial periods in China, but also its tectonic significance for breakup of Rodinia supercontinent. There are many Neoproterozoic glaciation strata exposures in Quruqtagh. The Nanhua System is divided into the Bayisi, Zhaobishan (absent in south aera), Altungol and Tereeken formations. Thick tillites were found in Bayisi, Tereeken and Hankalchough formations, while minor was found in Altungol Formation. After the field investigation of the south Yaerdang Mountain in the South aera, it is suggested that the Altungol Formation in the South aera differs from that the North aera. In the North, it is a set of littoral-neritic clastic facies sediment with few volcanic rocks and marine tillites in the bottom. In South Quruqtagh, it consists of 45m-thick gray-green tillites in the bottom with different size and complex components gravels, volcanic interbed near the top of tillites, overlying strata is cap dolomite of 15m thickness, with abundant drop-stones, the upper is black shales and gray to black thin-interbeded siliceous rock. The reported ages without Altungol glaciation age are all focused on the north Quruqtagh and conversely in South Quruqtagh without reported glaciation age. Based on field investigation of Nanhua System (Cryogenian) in NE Tarim Basin, we offer the first set of Sturtian glaciation age 729.4×6.6Ma, in the form of SHRIMP(sensitive high-resolution ion microprobe) U-Pb zircon age dating of volcanic interbedded near the top of Altungol Formation tillites, South Quruqtagh, which provides a new constraint on the Sturtian glaciation from global perspective. It is a

Identification of potential impacts of climate change and anthropogenic activities on streamflow alterations in the Tarim River Basin, China.

PubMed

Xue, Lianqing; Yang, Fan; Yang, Changbing; Chen, Xinfang; Zhang, Luochen; Chi, Yixia; Yang, Guang

2017-08-15

Understanding contributions of climate change and human activities to changes in streamflow is important for sustainable management of water resources in an arid area. This study presents quantitative analysis of climatic and anthropogenic factors to streamflow alteration in the Tarim River Basin (TRB) using the double mass curve method (DMC) and the Budyko methods. The time series (1960~2015) are divided into three periods: the prior impacted period (1960~1972) and the two post impacted periods, 1973~1986 and 1987~2015 with trend analysis. Our results suggest that human activities played a dominant role in deduction in the streamflow in TRB with contribution of 144.6% to 120.68% during the post impacted period I and 228.68% to 140.38% during the post impacted period II. Climatic variables accounted for 20.68%~44.6% of the decrease during the post impacted period I and 40.38% ~128.68% during the post impacted period II. Sensitivity analysis indicates that the streamflow alteration was most sensitive to changes in landscape parameters. The aridity index and all the elasticities showed an obvious increasing trend from the upstream to the downstream in the TRB. Our study suggests that it is important to take effective measures for sustainable development of eco-hydrological and socio-economic systems in the TRB.

Structural features of northern Tarim basin: Implications for regional tectonics and petroleum traps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong Jia; Juafu Lu; Dongsheng Cai

1998-01-01

The rhombus-shaped Tarim basin in northwestern China is controlled mainly by two left-lateral strike-slip systems: the northeast-trending Altun fault zone along its southeastern side and the northeast-trending Aheqi fault zone along its northwestern side. In this paper, we discuss the northern Tarim basin`s structural features, which include three main tectonic units: the Kalpin uplift, the Kuqa depression, and the North Tarim uplift along the northern margin of the Tarim basin. Structural mapping in the Kalpin uplift shows that a series of imbricated thrust sheets have been overprinted by strike-slip faulting. The amount of strike-slip displacement is estimated to be 148more » km by restoration of strike-slip structures in the uplift. The Kuqa depression is a Mesozoic-Cenozoic foredeep depression with well-developed flat-ramp structures and fault-related folds. The Baicheng basin, a Quaternary pull-apart basin, developed at the center of the Kuqa depression. Subsurface structures in the North Tarim uplift can be divided into the Mesozoic-Cenozoic and the Paleozoic lithotectonic sequences in seismic profiles. The Paleozoic litho-tectonic sequence exhibits the interference of earlier left-lateral and later right-lateral strike-slip structures. Many normal faults in the Mesozoic-Cenozoic litho-tectonic sequence form the negative flower structures in the North Tarim uplift; these structures commonly directly overlie the positive flower structures in the Paleozoic litho-tectonic sequence. The interference regions of the northwest-trending and northeast-trending folds in the Paleozoic tectonic sequence have been identified to have the best trap structures. Our structural analysis indicates that the Tarim basin is a transpressional foreland basin rejuvenated during the Cenozoic.« less

Relationship between deep structure and oil-gas in the eastern Tarim Basin

NASA Astrophysics Data System (ADS)

Yu, Changqing; Qu, Chen; Han, Jianguang

2017-04-01

The Tarim Basin is a large composite superimposed basin which developed in the Presinian continental basement. It is an important area for oil and gas replacement in China. In the eastern part of Tarim Basin, the exploration and research degree is very low and less system, especially in the study of tectonic evolution and physical property change. Basing on the study of geophysics, drilling and regional geological data in this area, analysis of comprehensive geophysical, geological and geophysical analysis comparison are lunched by new methods and new technology of geophysical exploration. Fault, tectonic evolution and change of deep character in the eastern Tarim Basin are analyzed in system. Through in-depth study and understanding of the deep structure and physical changes of the eastern region, we obtain the fault characteristics in the study area and the deep structure and physical change maps to better guide the oil and gas exploration in this area. The east area is located in the eastern Tarim Basin, west from the Garr Man depression, Well Kunan 1 - Well Gucheng 4 line to the East, north to Kuruketage uplift group near Qunke 1 wells, south to Cherchen fault zone, east to Lop Nor depression, an area of about 9 * 104 square kilometres, Including the East of Garr Man sag, Yingjisu depression, Kongquehe slope, Tadong low uplift and the Lop Nor uplift, five two grade tectonic units. The east area of Tarim is belonging to Tarim plate. It changes with the evolution of the Tarim plate. The Tarim plate is closely related to the collision between the Yining - the Junggar plate, the Siberia plate and the southern Qiangtang - the central Kunlun plate. Therefore, it creates a complex tectonic pattern in the eastern Tarim basin. Earth electromagnetic, gravity, deep seismic and other geophysical data are processed by a new generation of geophysical information theory and method, including multi-scale inversion of potential field inversion (Hou and Yang, 2011), 3D

Experimental study on water transport observations of desert riparian forests in the lower reaches of the Tarim River in China.

PubMed

Chen, Yaning; Li, Weihong; Zhou, Honghua; Chen, Yapeng; XinmingHao; Fu, Aihong; Ma, Jianxin

2017-06-01

Studying the water use processes of desert riparian vegetation in arid regions and analyzing the response and adaptation strategies of plants to drought stress are of great significance for developing ecological restoration measures. Based on field monitoring and test analyses of physiological ecological indicators of dominant species (Populus euphratica and Tamarix chinensis) in the desert riparian forest in the lower reaches of the Tarim River, the water relations of P. euphratica and T. chinensis under drought stress are discussed and some water use strategies put forward. The results show that (1) concerning plant water uptake, desert riparian forests depend mainly on groundwater to survive under long-term water stress. (2) Concerning plant water distribution, the survival of P. euphratica and nearby shallow root plants is mainly due to the hydraulic lift and water redistribution of P. euphratica under drought stress. (3) Concerning plant water transport, P. euphratica sustains the survival of competitive and advantageous branches by improving their ability to acquire water while restraining the growth of inferior branches. (4) Concerning plant transpiration, the sap flow curves of daily variations of P. euphratica and T. chinensis were wide-peak sin and narrower-peak respectively. T. chinensis has better environmental adaptability.

[Interrelations between plant communities and environmental factors of wetlands and surrounding lands in mid- and lower reaches of Tarim River].

PubMed

Zhao, Ruifeng; Zhou, Huarong; Qian, Yibing; Zhang, Jianjun

2006-06-01

A total of 16 quadrants of wetlands and surrounding lands in the mid- and lower reaches of Tarim River were surveyed, and the data about the characteristics of plant communities and environmental factors were collected and counted. By using PCA (principal component analysis) ordination and regression procedure, the distribution patterns of plant communities and the relationships between the characteristics of plant community structure and environmental factors were analyzed. The results showed that the distribution of the plant communities was closely related to soil moisture, salt, and nutrient contents. The accumulative contribution rate of soil moisture and salt contents in the first principal component accounted for 35.70%, and that of soil nutrient content in the second principal component reached 25.97%. There were 4 types of habitats for the plant community distribution, i. e., fenny--light salt--medium nutrient, moist--medium salt--medium nutrient, mesophytic--medium salt--low nutrient, and medium xerophytic-heavy salt--low nutrient. Along these habitats, swamp vegetation, meadow vegetation, riparian sparse forest, halophytic desert, and salinized shrub were distributed. In the wetlands and surrounding lands of mid- and lower reaches of Tarim River, the ecological dominance of the plant communities was markedly and unitary-linearly correlated with the compound gradient of soil moisture and salt contents. The relationships between species diversity, ecological dominance, and compound gradient of soil moisture and salt contents were significantly accorded to binary-linear regression model.

Interactions of Multiple Atmospheric Circulation Drive the Drought in Tarim River Basin.

PubMed

Wu, Yong-Ping; Feng, Guo-Lin; Li, Bai-Lian

2016-05-20

Global warming is likely to cause overall drying of land surfaces and aridity increasing leading to expansion of dry climate zones. There is an increased risk of extremely arid environment and large deserts developed progressively in the central Asia. However, the key factors causing the drying in mid-Asia remain inconclusive. Here, we analyzed the relationship among precipitation, water vapor transportation in Tarim River Basin (TRB) and Multiple Atmospheric Circulation (MAC) to explore the mechanism of MAC driving the drying in TRB, through comparing MAC between abundant and scarce precipitation years. We found that Westerly Circulation (WC) and Asian Summer Monsoon (ASM) are likely to promote the precipitation respectively. Whereas, they not only have their own influence but also restrict each other and facilitate the forming of peculiar water vapor transport channel for TRB, which is probably to restrain the precipitation and its distribution pattern and accelerate the drying in this region. Our results enrich the findings on mechanisms of wet places becoming wetter while dry areas getting drier under the global warming.

Interactions of Multiple Atmospheric Circulation Drive the Drought in Tarim River Basin

NASA Astrophysics Data System (ADS)

Wu, Yong-Ping; Feng, Guo-Lin; Li, Bai-Lian

2016-05-01

Global warming is likely to cause overall drying of land surfaces and aridity increasing leading to expansion of dry climate zones. There is an increased risk of extremely arid environment and large deserts developed progressively in the central Asia. However, the key factors causing the drying in mid-Asia remain inconclusive. Here, we analyzed the relationship among precipitation, water vapor transportation in Tarim River Basin (TRB) and Multiple Atmospheric Circulation (MAC) to explore the mechanism of MAC driving the drying in TRB, through comparing MAC between abundant and scarce precipitation years. We found that Westerly Circulation (WC) and Asian Summer Monsoon (ASM) are likely to promote the precipitation respectively. Whereas, they not only have their own influence but also restrict each other and facilitate the forming of peculiar water vapor transport channel for TRB, which is probably to restrain the precipitation and its distribution pattern and accelerate the drying in this region. Our results enrich the findings on mechanisms of wet places becoming wetter while dry areas getting drier under the global warming.

Estimation of subsurface formation temperature in the Tarim Basin, northwest China: implications for hydrocarbon generation and preservation

NASA Astrophysics Data System (ADS)

Liu, Shaowen; Lei, Xiao; Feng, Changge; Hao, Chunyan

2016-07-01

Subsurface formation temperature in the Tarim Basin, northwest China, is vital for assessment of hydrocarbon generation and preservation, and of geothermal energy potential. However, it has not previously been well understood, due to poor data coverage and a lack of highly accurate temperature data. Here, we combined recently acquired steady-state temperature logging data with drill stem test temperature data and measured rock thermal properties, to investigate the geothermal regime and estimate the subsurface formation temperature at depth in the range of 1000-5000 m, together with temperatures at the lower boundary of each of four major Lower Paleozoic marine source rocks buried in this basin. Results show that heat flow of the Tarim Basin ranges between 26.2 and 66.1 mW/m2, with a mean of 42.5 ± 7.6 mW/m2; the geothermal gradient at depth of 3000 m varies from 14.9 to 30.2 °C/km, with a mean of 20.7 ± 2.9 °C/km. Formation temperature estimated at the depth of 1000 m is between 29 and 41 °C, with a mean of 35 °C, while 63-100 °C is for the temperature at the depth of 3000 m with a mean of 82 °C. Temperature at 5000 m ranges from 97 to 160 °C, with a mean of 129 °C. Generally spatial patterns of the subsurface formation temperature at depth are basically similar, characterized by higher temperatures in the uplift areas and lower temperatures in the sags, which indicates the influence of basement structure and lateral variations in thermal properties on the geotemperature field. Using temperature to identify the oil window in the source rocks, most of the uplifted areas in the basin are under favorable condition for oil generation and/or preservation, whereas the sags with thick sediments are favorable for gas generation and/or preservation. We conclude that relatively low present-day geothermal regime and large burial depth of the source rocks in the Tarim Basin are favorable for hydrocarbon generation and preservation. In addition, it is found that the

Analysis of spatial pattern Change of LU/LC over the upper Tarim River region since 1990 using remote sensing data

NASA Astrophysics Data System (ADS)

Bai, L. Y.; Feng, J. Z.; Ma, Y. X.; Ran, Q. Y.; Wang, K.; Zhao, Y.

2017-02-01

The upper reaches of Tarim River (URTR) is an important port of trade between China and central Asia. The development of the URTR is thus significant for the SREB initiative. The LU/LC data in the URTR from 1990 to 2015 were used to quantitatively explore the dynamics of LU/LC changes, and its driving force was discussed from two aspects of nature and human. Results showed that the unused land and grassland were the main land use types in this area, accounting for more than 79%. Compared with the data of 1990, the areas of woodland, water, farmland, and building land of 2015 increased with 3.24%, 6.53%, 10.57%, and 0.40%, respectively, and the areas of unused land and grassland decreased, which accounted for 53.25% and 26.01%, respectively. The increases of the woodland and farmland areas mainly is originated from grassland and unused land. The woodland increased sharply around 2000 due to the abundant water during the period between 1998 and 2000. Subsequently, part of the woodland was shifted into the farmland. The extension of building land wasn’t obvious, but showed a salient feature of population urbanization. It was essential that the LU/LC patterns of the URTR were deeply influenced by human farming and living activities.

Origin and production process of eolian dust emitted from the Tarim Basin and their evolution through the Plio-Pleostocene based on ESR signal intensity and crystallinity of quartz

NASA Astrophysics Data System (ADS)

Tada, R.; Isozaki, Y.; Zheng, H.; Sun, Y.; Toyoda, S.; Hasegawa, H.; Yoshida, T.

2010-12-01

Tarim Basin (or Taklimakan Desert) is regarded as one of the major source area of eolian dust in the northern hemisphere. Although a previous study hypothesized that the detrital materials in the Tarim Basin were produced by glacial activity in the surrounding mountains, delivered by rivers, and homogenized by wind within the basin, not enough evidence has been presented to support this hypothesis. Here, we conducted provenance study of eolian dust in the Tarim Basin by examining fine silt fraction (< 20 μm) of the sediments collected from all over the Tarim Basin. We focused on quartz and measured its electron spin resonance [ESR] signal intensity and Crystallinity Index [CI] in the fine (<16μm) and coarse (> 64μm) fractions of various types of sediments including river sediments derived from the Kunlun and Tian Shan Mountains, dry lake sediments in the eastern part of the basin, and mountain loess on the northern slope of the Kunlun Mountains, to examine the process to produce eolian dust within the Tarim Basin. The result revealed that the coarse fractions of river sediments were derived from bedrocks exposed in the drainage area of each river, and that quartz in coarse fraction of the river sediment has ESR signal intensity and CI values unique to each river. ESR signal intensity and CI of quartz in fine fractions of river sediments discharged from the Tian Shan Mountains, which are located windward of the basin, and those discharged from mountainous rivers show values similar to the values for coarse fractions, suggesting that their sources are the same as those for the coarse fractions. On the other hand, ESR signal intensity and CI of quartz in fine fractions of river sediments discharged from the Kunlun Mountains show values different from those for the coarse fractions, and converged to the values close to the average values for the fine fractions of river sediments in the basin and also for the mountain loess, the latter represents the eolian dust

Soil wind erodibility based on dry aggregate-size distribution in the Tarim Basin

USDA-ARS?s Scientific Manuscript database

The Tarim Basin is an important source of airborne particulate matter that contributes to poor air quality in China. However, little attention has been given to estimating wind erodibility of soils in the region. The objective of this study was to determine the soil wind erodibility for six land use...

The earliest well-dated archeological site in the hyper-arid Tarim Basin and its implications for prehistoric human migration and climatic change

NASA Astrophysics Data System (ADS)

Han, WenXia; Yu, LuPeng; Lai, ZhongPing; Madsen, David; Yang, Shengli

2014-07-01

The routes and timing of human occupation of the Tibetan Plateau (TP) are crucial for understanding the evolution of Tibetan populations and associated paleoclimatic conditions. Many archeological sites have been found in/around the Tarim Basin, on the northern margin of the Tibetan Plateau. Unfortunately, most of these sites are surface sites and cannot be directly dated. Their ages can only be estimated based on imprecise artifact comparisons. We recently found and dated an archeological site on a terrace along the Keriya River. Our ages indicate that the site was occupied at ~ 7.0-7.6 ka, making it the earliest well-dated archeological site yet identified in the Tarim Basin. This suggests that early human foragers migrated into this region prior to ~ 7.0-7.6 ka during the early to mid-Holocene climatic optimum, which may have provided the impetus for populating the region. We hypothesize that the Keriya River, together with the other rivers originating from the TP, may have served as access routes onto the TP for early human foragers. These rivers may also have served as stepping stones for migration further west into the now hyper-arid regions of the Tarim Basin, leading ultimately to the development of the Silk Road.

Source, evolution and emplacement of Permian Tarim Basalts: Evidence from U-Pb dating, Sr-Nd-Pb-Hf isotope systematics and whole rock geochemistry of basalts from the Keping area, Xinjiang Uygur Autonomous region, northwest China

NASA Astrophysics Data System (ADS)

Zhang, Dayu; Zhou, Taofa; Yuan, Feng; Jowitt, Simon M.; Fan, Yu; Liu, Shuai

2012-04-01

Permian basalts distribute at least 250,000 km2, and underlie the southwest Tarim Basin in Xinjiang Uygur Autonomous region, northwest China. This vast accumulation of basalt is the main part of the Tarim Large Igneous Province (LIP). The basaltic units in the Lower Permian Kupukuziman and Kaipaizileike Formations in the Keping area, Tarim Basin; were the best exposure of the Permian basalt sequence in the basin. LA-ICP-MS U-Pb dating of zircon from the basal basaltic unit in the section gives an age of 291.9 ± 2.2 Ma (MSWD = 0.30, n = 17); this age, combined with previously published geochronological data, indicates that the basalts in the Tarim Basin were emplaced between 292 Ma and 272 Ma, with about 90% of the basalts being emplaced between 292 and 287 Ma. Basalts from the Keping area have high FeOT (10.8-18.6 wt.%), low Mg#s (0.26-0.60), and exhibit primitive mantle normalized patterns with positive Pb, P and Ti but negative Zr, Y and Ta anomalies. The basalts from both formations have similar 206Pb/204Pb (18.192-18.934), 207Pb/204Pb (15.555-15.598) and 208Pb/204Pb (38.643-38.793) ratios. The basalts also have high ɛSr(t) (45.7-62.1), low ɛNd(t) (-3.6 to -2.2) and low zircon ɛHf(t) (-4.84 to -0.65) values. These characteristics are typical of alkali basalts and suggest that the basalts within the Tarim Basin were derived from an OIB-type mantle source and interacted with enriched mantle (EMI-type) before emplacement. Rare earth element systematics indicate that the parental melts for the basalts were high-degree partial melts derived from garnet lherzolite mantle at the base of the lithosphere. Prior to emplacement, the Tarim Permian Basalts (TPB) underwent fractional crystallization and assimilated crustal material; the basalts were finally emplaced during crustal extension in an intra-plate setting. The wide distribution, deep source and high degree partial melting of the TPB was consistent with a mantle plume origin. The TPB and other coeval igneous

Windblown sediment transport and loss in a desert–oasis ecotone in the Tarim Basin

USDA-ARS?s Scientific Manuscript database

The Tarim Basin is regarded as one of the most highly erodible areas in China. Desert comprises 64% of the land use in the Basin, but the desert–oasis ecotone plays a prominent role in maintaining oasis ecological security and stability. Yet, little is known concerning the magnitude of windblown sed...

Annual distributions and variations of dust weather occurrence over the Tarim Basin, China

NASA Astrophysics Data System (ADS)

Zhao, Yong; Zhou, Yang; Wang, Minzhong; Huo, Wen; Huang, Anning; Yang, Xinhua; Yang, Fan

2018-04-01

The annual distribution and variations in dust weather occurrence (DWO) have been analyzed using monthly DWO data from 26 stations over the Tarim Basin during the period of 1961 to 2010. The results show that the DWO presents a significant decreasing trend for different parts of the Tarim Basin in recent decades. The monthly DWO has two peaks in the east and west. In the first half of the year, the peak is in April, but in the second half of the year, the peak is in September. According to the concentration period and concentration degree (CD) of DWO, we can find that the maximum DWO occurs in April in the eastern, western, and northern parts of the basin, but it occurs in May in the southern part. The dust weather season is shorter for the northern and eastern parts of the basin than those of the remaining parts. On average, the dust weather season initiates in April in the northeast and in May for the rest of the region. As an indicator for the length of dust weather season, the CD is significantly related to DWO, with a correlation coefficient of -0.51, revealing an interesting feature of regional climate change with declining DWO and declining dust weather season over the Tarim Basin. The correlation analysis exhibits that all the Arctic Oscillation, Antarctic Oscillation, and North Atlantic Oscillation have a negative relation with the DWO but a positive relation with the length of dust weather season.

Remote sensing research on fragile ecological environment in continental river basin

NASA Astrophysics Data System (ADS)

Wang, Ranghui; Peng, Ruyan; Zhang, Huizhi

2003-07-01

Based on some remote sensing data and software platform of image processing and analysis, the standard image for ecological thematic mapping is decided. Moreover, the vegetation type maps and land sandy desertification type maps are made. Relaying on differences of natural resources and ecological environment in Tarim River Basin, the assessment indicator system and ecological fragility index (EFI) of ecological environment are built up. The assessment results are very severely. That is, EFI is only 0.08 in Akesu River Basin, it belongs to slight fragility area. EFI of Yarkant River Basin and upper reaches of Tarim River Basin are 0.23 and 0.25 respectively, both of them belong to general fragility areas. Meanwhile, EFI of Hotan River Basin and middle reaches of Tarim River Basin are 0.32 and 0.49 respectively; they all belong to middle fragility areas. However, the fragility of the lower reaches of Tarim River Basin belongs to severe fragility area that the EFI is 0.87.The maladjustment among water with hot and land as well as salt are hindrance of energy transfer and material circulation and information transmission. It is also the main reason that caused ecological environment fragility.

Late Cenozoic Deformation in the Western Tarim Basin, NW China

NASA Astrophysics Data System (ADS)

Thompson, J. A.; Burbank, D. W.; Chen, J.; Li, T.

2009-12-01

The Tian Shan in NW China is one of the most active regions of intracontinental deformation in the world, accommodating a large fraction (~40%) of the shortening from the Indo-Eurasian collision. The western Tarim Basin, situated between the southern Tian Shan and Pamir Mountains, manifests this deformation through a series of east-west trending fault-related folds that have formed during the late Cenozoic. Previous studies in this region have focused on the kinematics, style, and timing of detachment folds related to folding within the foreland basin of the southern Tian Shan. In contrast, this study focuses on the deformation caused by fault-propagation folding resulting from the northward movement of the Pamir. The rates of deformation are calculated using a combination of optically stimulated luminescence (OSL) ages, structural mapping and differential GPS surveys of fault scarps and deformed terrace surfaces crossing active folds. OSL dating provides the time since the sediment was last exposed to daylight, i.e., time since burial. Consequently, OSL is useful for dating the abandonment of terrace surfaces due to tectonic (fold growth) or climatic events. OSL quartz samples were collected from silt lenses within gravel topping the terraces. Most of the quartz OSL signals are weak, thus several grain sizes (silt (4-11 µm, 8-15 µm) and sand (90-125 µm)) were analyzed and different integrations of the shine-down curves were explored to calculate equivalent doses. The implications for different equivalent doses and ages on the calculation of rates of deformation are also addressed.

Concept for a Wireless Sensor Network to support GIS based water and land resource management in the Aksu-Tarim Basin, Xinjiang, China

NASA Astrophysics Data System (ADS)

Doluschitz, Reiner; Feike, Til

2013-04-01

Farmers in the oases along the Aksu-Tarim River suffer from severe seasonal water shortage caused by high fluctuations of river run-off. The uncertainty of water availability makes the planning of crop production and related investments extremely difficult. As a consequence farm management is often sub-optimal, manifesting in low input efficiencies, and the value generated in the agricultural sector being way below its potential. The "Tarim Basin Water Resource Bureau" (TBWRB) was founded in the 1990s. Its major task is to implement a basin wide water resources management plan, which involves fair allocation of water resources among the farmers in the different administrative units along the river. Among others, the lack of reliable and timely information on water quantities and qualities within the major water bodies of the basin hinders the implementation of an effective water management plan. Therefore we introduce the concept of a wireless sensor network (WSN) that provides reliable instantaneous information on the status of all important water resources within the basin. In the first step a GIS including all vital geospatial data, like river courses, channel and reservoir network and capacities, soil and land use map, is built. In the second step a WSN that monitors all important parameters at essential positions throughout the basin needs to be established. Measured parameters comprise meteorological data, river run-off, water levels of reservoirs, groundwater levels, and salinity levels of water resources. All data is centrally collected and processed by the TBWRB. Apart from generating a prompt and complete picture of currently available water resources, the TBWRB can use the system to record actual water allocation, and develop an early warning system for upcoming droughts or floods. Finally an integrated water and land management scheme can be established that allocates resources maximizing the benefits at basin level. Financed by public funding, the data

Lithospheric density structure beneath the Tarim basin and surroundings, northwestern China, from the joint inversion of gravity and topography

USGS Publications Warehouse

Deng, Yangfan; Levandowski, William Brower; Kusky, Tim

2017-01-01

Intraplate strain generally focuses in discrete zones, but despite the profound impact of this partitioning on global tectonics, geodynamics, and seismic hazard, the processes by which deformation becomes localized are not well understood. Such heterogeneous intraplate strain is exemplified in central Asia, where the Indo-Eurasian collision has caused widespread deformation while the Tarim block has experienced minimal Cenozoic shortening. The apparent stability of Tarim may arise either because strain is dominantly accommodated by pre-existing faults in the continental suture zones that bound it—essentially discretizing Eurasia into microplates—or because the lithospheric-scale strength (i.e., viscosity) of the Tarim block is greater than its surroundings. Here, we jointly analyze seismic velocity, gravity, topography, and temperature to develop a 3-D density model of the crust and upper mantle in this region. The Tarim crust is characterized by high density, vs, vp, and vp/vs, consistent with a dominantly mafic composition and with the presence of an oceanic plateau beneath Tarim. Low-density but high-velocity mantle lithosphere beneath southern (southwestern) Tarim underlies a suite of Permian plume-related mafic intrusions and A-type granites sourced in previously depleted mantle lithosphere; we posit that this region was further depleted, dehydrated, and strengthened by Permian plume magmatism. The actively deforming western and southern margins of Tarim—the Tien Shan, Kunlun Shan, and Altyn Tagh fault—are underlain by buoyant upper mantle with low velocity; we hypothesize that this material has been hydrated by mantle-derived fluids that have preferentially migrated along Paleozoic continental sutures. Such hydrous material should be weak, and herein strain focuses there because of lithospheric-scale variations in rheology rather than the pre-existence of faults in the brittle crust. Thus this world-class example of strain partitioning arises not

Neoproterozoic stratigraphic framework of the Tarim Craton in NW China: Implications for rift evolution

NASA Astrophysics Data System (ADS)

Wu, Lin; Guan, Shuwei; Zhang, Shuichang; Yang, Haijun; Jin, Jiuqiang; Zhang, Xiaodan; Zhang, Chunyu

2018-06-01

The Tarim Craton is overlain by thick Neoproterozoic sedimentary successions in rift tectonic setting. This study examines the latest outcrop, seismic, and drilling core data with the objective of investigating the regional stratigraphy to deeply recognize the evolution of rifting in the craton. Cryogenian to Lower Ediacaran successions are mainly composed of clastic rocks with thicknesses of 2000-3000 m, and the Upper Ediacaran successions are composed of carbonate rocks with thicknesses of 500-800 m. The rift basins and stratigraphic zones are divided into northern and southern parts by a central paleo-uplift. The northern rift basin extends through the northern Tarim Craton in an E-W direction with two depocenters (Aksu and Kuruktag). The southern rift basin is oriented NE-SW. There are three or four phases of tillites in the northern zone, while there are two in the southern zone. Given the north-south difference of the stratigraphic framework, the northern rift basin initiated at ca. 740 Ma and the southern rift basin initiated at ca. 780 Ma. During the Cryogenian and Ediacaran, the northern and southern rift basins were separated by the central paleo-uplift, finally connecting with each other in the early Cambrian. Tectonic deformation in the Late Ediacaran led to the formation of a parallel unconformity in the rift basins and an angular unconformity in the central paleo-uplift. The Neoproterozoic rift basins continued to affect the distribution of Lower Cambrian hydrocarbon source rocks. The north-south distribution and evolution of the rift basins in the Tarim Craton have implications for reconstructions of the Rodinia supercontinent.

Hydrochemistry of inland rivers in the north Tibetan Plateau: Constraints and weathering rate estimation.

PubMed

Wu, Weihua

2016-01-15

The geographic region around the northern and northeastern Tibetan Plateau is the source of several inland rivers (e.g. Tarim River) of worldwide importance that are generated in the surrounding mountains systems of Tianshan, Pamir, Karakorum, and Qilian. To characterize chemical weathering and atmospheric CO2 consumption in these regions, water samples from the Tarim, Yili, Heihe, Shule, and Shiyang Rivers were collected and analyzed for major ion concentrations. The hydrochemical characteristics of these inland rivers pronouncedly distinguish them from large exorheic rivers (e.g., the Yangtze River and the Yellow River), as reflected in very high total dissolution solids (TDS) values. TDS was 115-4345 mg l(-1) with an average of 732 mg l(-1), which is an order of magnitude higher than the mean value for world rivers (65 mg l(-1)). The Cheerchen River, Niya River, Keliya River and the terminal lakes of the Tarim River and the Heihe River have TDS values higher than 1 gl(-1), indicating saline water that cannot be directly consumed. Therefore, the problem of sufficient and safe drinking water has become increasingly prominent in the northwestern China arid zone. According to an inversion model, the contribution from evaporite dissolution to the dissolved loads in these rivers is 12.5%-99% with an average of 54%. The calculated silicate and carbonate weathering rates are 0.02-4.62 t km(-2)y(-1) and 0.01-11.7 t km(-2)y(-1) for these rivers. To reduce the influence of lithology, only the silicate weathering rates in different parts of the Tibetan Plateau are compared. A rough variation tendency can be seen in the rates: northern regional (0.15-1.73 t km(-2)y(-1))

Geochemistry and geochronology of the ∼0.82 Ga high-Mg gabbroic dykes from the Quanji Massif, southeast Tarim Block, NW China: Implications for the Rodinia supercontinent assembly

NASA Astrophysics Data System (ADS)

Liao, Fanxi; Wang, Qinyan; Chen, Nengsong; Santosh, M.; Xu, Yixian; Mustafa, Hassan Abdelsalam

2018-05-01

The role of the Tarim Block in the reconstruction of the Neoproterozoic supercontinent Rodinia remains contentious. Here we report a suite of high-Mg gabbroic dykes from the Yingfeng area in northwestern Quanji Massif, which is considered as a fragment of the Tarim Block in NW China. Magmatic zircons from these dykes yield to have a weighted mean 206Pb/238U age of 822.2 ± 5.3 Ma, recording the timing of their emplacement. The gabbros have high MgO (9.91-13.09 wt%), Mg numbers (69.89-75.73) and CaO (8.41-13.55 wt%), medium FeOt (8.50-9.67 wt%) and TiO2 (0.67-0.93 wt%), variable Al2O3 (13.04-16.07 wt%), and high Cr (346.14-675.25 ppm), but relatively low Ni (138.72-212.94 ppm), suggestive of derivation from a primary magma. The rocks display chondrite-normalized LREE patterns with weak fractionation but flat HREE patterns relative to those of the N-MORB. Their primitive mantle normalized trace elemental patterns show positive Rb, Ba and U but negative Th, Nb, Ti and Zr anomalies, carrying characteristics of both mid-ocean ridge basalts and arc basalts. The εHf(t) values of the zircons from these rocks vary from +4.7 to +13.5 with depleted mantle model ages (TDM) of 1.23-0.85 Ga, and the youngest value nearly approaching that for the coeval depleted mantle, suggesting significant addition of juvenile materials. Our data suggest that the strongly depleted basaltic magma was probably sourced from a depleted mantle source that had undergone metasomatism by subduction-related components in a back-arc setting. Accordingly we postulate that a subduction-related tectonic regime possibly prevailed at ∼0.8 Ga along the southeastern margin of the Tarim Block. Combining with available information from the northern Tarim Block, we propose an opposite verging double-sided subduction model for coeval subduction of the oceanic crust beneath both the southern and northern margins of the Tarim Block during early Neoproterozoic.

High Resolution Biostratigraphy and the Origin of the Basal Cambrian Bedded Chert from the Aksu Area (Tarim Block, Northwestern China)

NASA Astrophysics Data System (ADS)

Wang, Z.; Liu, H.; Dong, L.

2017-12-01

The early Cambrian Yurtus Formation in the Aksu area (Tarim block, northwestern China) consists of two lithostratigraphic units, lower black shale with interbedded chert unit and upper siltstone/carbonate unit. This time period represents the most important Proterozoic- Phanerozoic transition in earth's history. In recent years, the black shale has been confirmed to have high hydrocarbon generation potential. However, the depositional environment of the Yurtus Formation remains controversial and the biostratigraphic constrains are rather poor. The chert that is interbedded with black shale in the Yurtus Formation provides an exceptional taphonomic window to capture the diversity of the early Cambrian microfossils. Meanwhile, the origin of the bedded chert would give us some insight into the environmental background when the source rock was deposited. Therefore, in this research, we focus on the chert in the lower Yurtus formation and our purpose is to establish high resolution biostratigraphic framework and to better understand the depositional environment of the source rock. We investigated 4 sections in the Tarim basin: Kungaikuotan, Sugaite, Kule, and Yurtus VI. Abundant acritarch fossils have been identified, including Heliosphaeridium ampliatum, Yurtusia uniformis, and Comasphaeridium annulare. The tubular fossil Megathrix longus is also very common in this formation. In addition, two new types of specimens have been discovered, sheet-like encrolled fossils ( 0.5 mm in size) and regular spindle-like double layered microfossils ( 10μm in diameter). All of these fossils have constant occurrences in the studied sections, and can be well correlated with those yielded from the equivalent interval in South China. The biostratigraphic work suggests the source rock in the lower unit of the Yurtus Formation could be correlated with the Meishucunian small shelly fossil assemblage I and II. The Gemenium/Silicon ratio of the Yurtus chert is less than 1�

Modern dust aerosol availability in northwestern China.

PubMed

Wang, Xunming; Cheng, Hong; Che, Huizheng; Sun, Jimin; Lu, Huayu; Qiang, Mingrui; Hua, Ting; Zhu, Bingqi; Li, Hui; Ma, Wenyong; Lang, Lili; Jiao, Linlin; Li, Danfeng

2017-08-18

The sources of modern dust aerosols and their emission magnitudes are fundamental for linking dust with climate and environment. Using field sample data, wind tunnel experiments and statistical analysis, we determined the contributions of wadis, gobi (stony desert), lakebeds, riverbeds, and interdunes to modern dust aerosol availability in the three important potential dust sources including the Tarim Basin, Qaidam Basin, and Ala Shan Plateau of China. The results show that riverbeds are the dominant landscape for modern dust aerosol availabilities in the Qaidam Basin, while wadis, gobi, and interdunes are the main landscapes over the Ala Shan Plateau and Tarim Basin. The Ala Shan Plateau and Tarim Basin are potential dust sources in northwestern China, while the Qaidam Basin is not a major source of the modern dust aerosols nowadays, and it is not acting in a significant way to the Loess Plateau presently. Moreover, most of modern dust aerosol emissions from China originated from aeolian processes with low intensities rather than from major dust events.

Yellow River Delta, China

NASA Image and Video Library

2009-12-08

The Yellow River is the second-longest river in China, and the sixth longest in the world and makes many dramatic shifts over time. This image was taken with the ASTER instrument aboard NASA Terra spacecraft in 2009.

Land cover of oases and forest in XinJiang, China retrieved from ASTER data

NASA Astrophysics Data System (ADS)

Buhe, Aosier; Tsuchiya, K.; Kaneko, M.; Ohtaishi, N.; Halik, Mahmut

ASTER aboard NASA’s satellite Terra is a high-resolution multispectral radiometer of 14 bands. The spatial resolution is 15 m in VNIR, 30 m in SWIR and 90 m in TIR spectra, respectively. With the data observed with ASTER, the land cover classification is produced for the Tarim Diversifolious Poplar Protection Area along the Tarim River in the northern Tarim Basin (Taklamakan Desert) in XinJiang, China. The classification of the vegetation (plants) in the arid and semiarid regions using remote-sensing technology is very difficult. Because the cause has low vegetable cover density and the influence of reflection from background soil is large. ASTER data are effective in studying the spectrum characteristics of land cover in arid and semiarid regions. The sensor has several bands in the shortwave infrared wavelength region that is designed for exploration of earth resources and study of the arid and semiarid region natural environment. However, we are not clear combination of which band is the most effective in research of the arid region like the Taklamakan desert in the data of 14 bands of ASTER. The optimum index factor (OIF), based on total variance within bands and correlation coefficient between bands, is a statistical approach to rank all possible three-band combinations. In the process of analyzing the data, the pixel sizes of all the data are converted (layer stacking and re-sampling) into consistent same size of 15 m. The three-band composite with the largest OIF value will have most information (as measured by variance) with the least amount of duplication (as measured by correlation). We used the OIF technique to rank all three-band combinations of ASTER original 14-band data over Tarim River Poplar Protection Area. Our study indicates that RGB color overlay using atmospheric corrected ASTER original bands 2, 3 (VNIR), and 6 (SWIR) has the highest OIF. When NDVI is considered as one ASTER band, highest OIF will have by carrying out bands 3 (VNIR), 4

Fauna of Cladocera and Copepoda from Xinjiang Uyghur Autonomous Region (China).

PubMed

Chertoprud, Elena S; Sinev, Artem Y; Dimante-Deimantovica, Inta

2017-05-03

This study evaluates the species composition of Cladocera and Copepoda in the five lakes of the Bogda-Shan Mountain range and in the floodplain of the Tarim and Konchedarya rivers located in the Xinjiang Uygur Autonomous Region of China (Xinjiang). We collected seven species of Cladocera and six species of Copepoda. Seven species were identified as new for Xinjiang fauna, and two species (Cyclops cf. herberti Einsle, 1996, and Eucyclops roseus Ishida, 1997) were first records for China. Herein, we characterize the distribution ranges for the detected species and provide taxonomic remarks. The total species list for water bodies in Xinjiang compiled from original data and available literature includes 56 species of Cladocera and 33 species of Copepoda. We also discuss the biogeographical structure of Cladocera and Copepoda faunas in Xinjiang.

The Cretaceous - Paleogene paleogeography of Central Asia recorded in depositional environments of the Proto-Paratethys Sea in the Tarim Basin (Western China)

NASA Astrophysics Data System (ADS)

Yücel Kaya, Mustafa; Dupont-Nivet, Guillaume; Proust, Jean-Noel; Bougeois, Laurie; Meijer, Niels; Frieling, Joost; Fioroni, Chiara; Stoica, Marius; Roperch, Pierrick; Mamtimin, Mehmut; Aminov, Jovid

2017-04-01

The Proto-Paratethys, a shallow epicontinental sea, extended from Cretaceous to Paleogene times across Eurasia from the Mediterranean Tethys to the Tarim Basin in western China. Transgressive and regressive episodes of the Proto-Paratethys Sea have been previously recognized but their timing, extent and depositional environments remain poorly constrained especially for the Cretaceous and early Paleogene. This hampers understanding of their driving mechanisms (geodynamic and/or eustatic) and paleoclimatic consequences on regional aridification and monsoons. As part of the ERC "MAGIC" project, we report an integrated sedimentologic and stratigraphic analysis of the Proto-Paratethys from its initial Cretaceous onset to the final Paleogene retreat from multiple investigated sections in the western border of Tarim Basin. Facies associations include field observations and microfacies analyses from carbonate samples. New bio- and magneto-stratigraphic results from key intervals are also provided to testify the previously constructed regional stratigraphic framework. The previously controversial number of marine incursions in the Tarim Basin is resolved to 6 (3 Cretaceous and 3 Paleogene) also recognized in the neighboring Tajik and Turan Basins to the west and the present-day Alai Valley. The eastward extent of these marine incursions varied through time with a maximum extent during late Paleocene - early Eocene. The first marine incursion is a Cenomanian transgression recorded in the marls and calcareous mudstones of the Kukebai Formation. The next two are Coniacian and Campanian transgressions recognized in the carbonate units of the Yigeziya Formation. The first Paleogene incursion is characterized by thick evaporites of the Paleocene Aertashi Formation overlain by the marine shales of the Lower Qimugen Formation. The latter represents the maximum extent and the deepest environments of the Proto-Paratethys. The marine Kalatar limestones and silty shales of the Wulagen

Gravity anomalies and the structure of western Tibet and the southern Tarim Basin

NASA Technical Reports Server (NTRS)

Lyon-Caen, H.; Molnar, P.

1984-01-01

Gravity anomalies across the western part of the Tarim Basin and the Kunlun mountain belt show that this area is not in local isostatic equilibrium. These data can be explained if a strong plate underlying the Tarim Basin extends southwestward beneath the belt at least 80 km and supports part of the topography of northwest Tibet. This corroborates Norin's inference that late Tertiary crustal shortening has occurred in this area by southward underthrusting of the Tarim Basin beneath the Kunlun. This study places a lower bound on the amount of underthrusting.

The significance of 24-norcholestanes, triaromatic steroids and dinosteroids in oils and Cambrian-Ordovician source rocks from the cratonic region of the Tarim Basin, NW China

USGS Publications Warehouse

Li, Meijun; Wang, T.-G.; Lillis, Paul G.; Wang, Chunjiang; Shi, Shengbao

2012-01-01

Two oil families in Ordovician reservoirs from the cratonic region of the Tarim Basin are distinguished by the distribution of regular steranes, triaromatic steroids, norcholestanes and dinosteroids. Oils with relatively lower contents of C28 regular steranes, C26 20S, C26 20R + C27 20S and C27 20R regular triaromatic steroids, dinosteranes, 24-norcholestanes and triaromatic dinosteroids originated from Middle–Upper Ordovician source rocks. In contrast, oils with abnormally high abundances of the above compounds are derived from Cambrian and Lower Ordovician source rocks. Only a few oils have previously been reported to be of Cambrian and Lower Ordovician origin, especially in the east region of the Tarim Basin. This study further reports the discovery of oil accumulations of Cambrian and Lower Ordovician origin in the Tabei and Tazhong Uplifts, which indicates a potential for further discoveries involving Cambrian and Lower Ordovician sourced oils in the Tarim Basin. Dinosteroids in petroleum and ancient sediments are generally thought to be biomarkers for dinoflagellates and 24-norcholestanes for dinoflagellates and diatoms. Therefore, the abnormally high abundance of these compounds in extracts from the organic-rich sediments in the Cambrian and Lower Ordovician and related oils in the cratonic region of the Tarim Basin suggests that phytoplankton algae related to dinoflagellates have appeared and might have flourished in the Tarim Basin during the Cambrian Period. Steroids with less common structural configurations are underutilized and can expand understanding of the early development history of organisms, as well as define petroleum systems.

Yellow River, China

NASA Image and Video Library

1994-09-30

STS068-220-033 (30 September-11 October 1994) --- Photographed through the Space Shuttle Endeavour's flight deck windows, this 70mm frame shows a small section of China's Yellow River (Huang Ho) highlighted by sunglint reflection off the surface of the water. The river flows northeastward toward the village of Tung-lin-tzu. The low dissected mountains that cover more than half of this scene rise some 2,000 feet (on the average) above the valley floor. A major east-west transportation corridor (both railway and automobile) is observed traversing the landscape north of the river. This entire region is considered to be part of the Ordos Desert, actually part of the greater Gobi located just north of this area. Approximate center coordinates of this scene are 37.5 degrees north latitude and 105.0 degrees east longitude.

Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt.

PubMed

Wang, Lei; Tian, Wei; Shi, Yongmin

2017-08-07

The morphology and structure of plumbing systems can provide key information on the eruption rate and style of basalt lava fields. The most powerful way to study subsurface geo-bodies is to use industrial 3D reflection seismological imaging. However, strategies to image subsurface volcanoes are very different from that of oil and gas reservoirs. In this study, we process seismic data cubes from the Northern Tarim Basin, China, to illustrate how to visualize sills through opacity rendering techniques and how to image the conduits by time-slicing. In the first case, we isolated probes by the seismic horizons marking the contacts between sills and encasing strata, applying opacity rendering techniques to extract sills from the seismic cube. The resulting detailed sill morphology shows that the flow direction is from the dome center to the rim. In the second seismic cube, we use time-slices to image the conduits, which corresponds to marked discontinuities within the encasing rocks. A set of time-slices obtained at different depths show that the Tarim flood basalts erupted from central volcanoes, fed by separate pipe-like conduits.

Semi-natural areas of Tarim Basin in northwest China: Linkage to desertification.

PubMed

Liu, Fang; Zhang, Hongqi; Qin, Yuanwei; Dong, Jinwei; Xu, Erqi; Yang, Yang; Zhang, Geli; Xiao, Xiangming

2016-12-15

Semi-natural lands are not intensively managed lands, which have ecological significance in protecting artificial oasis and preventing desertification in arid regions. The significant shrinkage and degradation of semi-natural lands in the land-use intensification process have caused severe desertification. However, there is a knowledge gap regarding the spatio-temporal pattern and detailed classification of semi-natural lands and its quantitative relationship with desertification. Taking the Tarim Basin as an example, we proposed a comprehensive classification system to identify semi-natural lands for 1990, 2000, and 2010, respectively, using multi-source datasets at large scales. Spatio-temporal changes of semi-natural lands were then characterized by map comparisons at decade intervals. Finally, statistical relationships between semi-natural lands and desertification were explored based on 241 watersheds. The area of semi-natural lands in Tarim Basin was 10.77×10 4 km 2 in 2010, and desert-vegetation type, native-oasis type, artificial-oasis type, saline type and wetland type accounted for 59.59%, 14.65%, 11.25%, 9.63% and 4.88% of the total area, respectively. A rapid loss of semi-natural lands (9769.05km 2 ) was demonstrated from 1990 to 2010. In the fragile watersheds, the semi-natural lands were mainly converted to desert; while in the watersheds with advanced oasis agriculture, artificial-oasis type reclaimed to arable land was the major change. The occurrence of desertification was closely related to the type, area proportion and combination patterns of semi-natural lands. Desertification was prone to occur in regions abundant in desert-vegetation type and saline type, while less serious desertification was observed in regions with high proportion of artificial-oasis type and wetland type. Policy intervention and reasonable water resource allocation were encouraged to prevent the substantial loss of semi-natural lands, especially for the water

Windblown sediment transport and loss in a desert-oasis ecotone in the Tarim Basin.

PubMed

Pi, Huawei; Sharratt, Brenton; Lei, Jiaqiang

2017-08-10

The Tarim Basin is regarded as one of the most highly erodible areas in China. Desert comprises 64% of the land use in the Basin, but the desert-oasis ecotone plays a prominent role in maintaining oasis ecological security and stability. Yet, little is known concerning the magnitude of windblown sediment transport in a desert-oasis ecotone. Therefore, aeolian sediment transport and loss was assessed from a desert-oasis experimental site located near Alaer City in the northwestern Tarim Basin. Sediment transport and factors governing transport were measured during three high wind events in 2012 and four events in 2013. Sediment transport was measured to a height of 10 m using passive aeolian airborne sediment samplers. The mass flux profile over the eroding surface was well represented by the power-law (R 2  > 0.77). Sediment loss from the site ranged from 118 g m -2 for the 20-24Apr 2012 wind event to 2925 g m -2 for the 31Mar-11Apr 2012 event. Suspension accounted for 67.4 to 84.8% of sediment loss across all high wind events. Our results indicate the severity of wind erosion in a desert-oasis ecotone and thus encourage adoption of management practices that will enhance oasis ecological security.

[Monitoring of soil salinization in Northern Tarim Basin, Xinjiang of China in dry and wet seasons based on remote sensing].

PubMed

Yao, Yuan; Ding, Jian-Li; Zhang, Fang; Wang, Gang; Jiang, Hong-Nan

2013-11-01

Soil salinization is one of the most important eco-environment problems in arid area, which can not only induce land degradation, inhibit vegetation growth, but also impede regional agricultural production. To accurately and quickly obtain the information of regional saline soils by using remote sensing data is critical to monitor soil salinization and prevent its further development. Taking the Weigan-Kuqa River Delta Oasis in the northern Tarim River Basin of Xinjiang as test object, and based on the remote sensing data from Landsat-TM images of April 15, 2011 and September 22, 2011, in combining with the measured data from field survey, this paper extracted the characteristic variables modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), and the third principal component from K-L transformation (K-L-3). The decision tree method was adopted to establish the extraction models of soil salinization in the two key seasons (dry and wet seasons) of the study area, and the classification maps of soil salinization in the two seasons were drawn. The results showed that the decision tree method had a higher discrimination precision, being 87.2% in dry season and 85.3% in wet season, which was able to be used for effectively monitoring the dynamics of soil salinization and its spatial distribution, and to provide scientific basis for the comprehensive management of saline soils in arid area and the rational utilization of oasis land resources.

Cenozoic Deformation of the Tarim Basin (Xinjiang, China): a Record of the Deformation Propagation through the Asian Orogenic System

NASA Astrophysics Data System (ADS)

Laborde, A.; Barrier, L.; Simoes, M.; Li, H.

2016-12-01

During the Cenozoic, the ongoing India-Eurasia collision resulted in the formation of the Himalayan-Tibetan plateau and reactivated the Tian Shan and Altai ranges located thousands of kilometers further north. Despite numerous studies carried out on the geology and tectonics of this large convergent orogenic system, several mechanisms remain controversial such as the stress propagation through the Asia Continent or the strain partitioning between crustal thickening and lateral extruding of its lithosphere. Located between the Tibetan Plateau and the Tian Shan Range, the Tarim Basin and its several kilometres thick Cenozoic sediments derived from the surrounding mountain belts are key recorders to reconstruct the evolution of the latters. Moreover, this basin is often considered as a relatively rigid block, which behaved as a secondary ``indenter'' transmitting collisional stresses to the Tian Shan. However, due to the size of the Tarim and its thick Cenozoic sedimentary series hiding most of its structures, the constraints on the spatial distribution and timing of the its Cenozoic deformation remain fragmentary. Therefore, the main objective of our study was to produce a synthetic view of this deformation at the scale of the whole basin. Based on numerous surface and subsurface data (satellite images, field surveys, seismic profiles, and well data), we established a tectonic map of the Cenozoic structures in the region and built balanced geological cross-sections across the basin. Our surface and subsurface observations confirm that, contrary to what had been proposed, the Tarim block has also undergone a major deformation during the Cenozoic. The quantification and history of this deformation provide useful insights into the modalities of the crustal shortening in the area and the problems of stress propagation and strain partitioning following the Indo-Asian collision.

Depositional environments and cyclicity of the Early Ordovician carbonate ramp in the western Tarim Basin (NW China)

NASA Astrophysics Data System (ADS)

Guo, Chuan; Chen, Daizhao; Song, Yafang; Zhou, Xiqiang; Ding, Yi; Zhang, Gongjing

2018-06-01

During the Early Ordovician, the Tarim Basin (NW China) was mainly occupied by an extensive shallow-water carbonate platform, on which a carbonate ramp system was developed in the Bachu-Keping area of the western part of the basin. Three well-exposed typical outcrop sections of the Lower Ordovician Penglaiba Formation were investigated in order to identify the depositional facies and to clarify origins of meter-scale cycles and depositional sequences, thereby the platform evolution. Thirteen lithofacies are identified and further grouped into three depositional facies (associations): peritidal, restricted and open-marine subtidal facies. These lithofacies are vertically stacked into meter-scale, shallowing-upward peritidal and subtidal cycles. The peritidal cycles are mainly distributed in the lower and uppermost parts of the Penglaiba Formation deposited in the inner-middle ramp, and commonly start with shallow subtidal to intertidal facies followed by inter- to supratidal facies. In contrast, the subtidal cycles occur throughout the formation mostly in the middle-outer ramp and are dominated by shallow to relatively deep (i.e., intermediate) subtidal facies. The dominance of asymmetrical and incomplete cycles suggests a dominant control of Earth's orbital forcing on the cyclic deposition on the platform. On the basis of vertical facies and cycle stacking patterns, and accommodation changes illustrated by the Fischer plots from all studied sections, five third-order depositional sequences are recognized in the Penglaiba Formation. Individual sequences comprise a lower transgressive part and an upper regressive one. In shallow-water depositional environments, the transgressive packages are dominated by thicker-than-average subtidal cycles, indicating an increase in accommodation space, whereas regressive parts are mainly represented by thinner-than-average peritidal and subtidal cycles, denoting a decrease in accommodation space. In contrast, in intermediate to

[Bayesian geostatistical prediction of soil organic carbon contents of solonchak soils in nor-thern Tarim Basin, Xinjiang, China.

PubMed

Wu, Wei Mo; Wang, Jia Qiang; Cao, Qi; Wu, Jia Ping

2017-02-01

Accurate prediction of soil organic carbon (SOC) distribution is crucial for soil resources utilization and conservation, climate change adaptation, and ecosystem health. In this study, we selected a 1300 m×1700 m solonchak sampling area in northern Tarim Basin, Xinjiang, China, and collected a total of 144 soil samples (5-10 cm). The objectives of this study were to build a Baye-sian geostatistical model to predict SOC content, and to assess the performance of the Bayesian model for the prediction of SOC content by comparing with other three geostatistical approaches [ordinary kriging (OK), sequential Gaussian simulation (SGS), and inverse distance weighting (IDW)]. In the study area, soil organic carbon contents ranged from 1.59 to 9.30 g·kg -1 with a mean of 4.36 g·kg -1 and a standard deviation of 1.62 g·kg -1 . Sample semivariogram was best fitted by an exponential model with the ratio of nugget to sill being 0.57. By using the Bayesian geostatistical approach, we generated the SOC content map, and obtained the prediction variance, upper 95% and lower 95% of SOC contents, which were then used to evaluate the prediction uncertainty. Bayesian geostatistical approach performed better than that of the OK, SGS and IDW, demonstrating the advantages of Bayesian approach in SOC prediction.

The provenance of Taklamakan desert sand

NASA Astrophysics Data System (ADS)

Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

2016-03-01

Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run

[Distribution and sources of polycyclic aromatic hydrocarbons in sediments from rivers of Pearl River Delta and its nearby South China Sea].

PubMed

Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian; Zeng, Yong-Ping; Sheng, Guo-Ying; Fu, Jia-Mo

2005-07-01

Polycyclic aromatic hydrocarbons (PAHs) are measured in surface sediments from rivers and estuary of Pearl River Delta and its nearby South China Sea. Total PAH concentration varied from 255.9 - 16 670.3 ng/g and a moderate to low level compare to relevant areas worldwide. The order of PAHs concentration in sediments was: rivers of Pearl River Delta > estuary > South China Sea, and the most significant PAH contamination was at Guangzhou channel of Zhujiang river. A decrease trend for PAHs concentration with distance from estuary to open sea can be sees in South China Sea. Coal and biomass combustion is the major source of PAHs in nearshore of South China Sea, and petroleum combustion is the main source of pyrolytic PAHs in rivers and estuary of Pearl River Delta according to PAHs diagnostic ratios. Petroleum PAHs are revealed have a high contribution to PAHs in Xijiang River, estuary and some stations in Zhujiang River. A comparison of data from study in 1997 with data from present study indicates that there is no clear change in the PAH concentration over time but the source of PAHs in Pearl River Delta have been change from a main coal combustion to petroleum combustion and being reflect in the sediments in rivers and estuary of Pearl River Delta where there have high sedimentation rate.

Analysis of the ancient river system in Loulan period in Lop Nur region

NASA Astrophysics Data System (ADS)

Zhu, Jianfeng; Jia, Peng; Nie, Yueping

2010-09-01

The Lop Nur region is located in the east of the Tarim Basin. It has served as the strategic passage and communication hub of the Silk Road since Han Dynasty. During Wei-Jin period, the river system there was well developed and the ancient city of Loulan was bred there. In this study, GIS is used to accomplish automatic extraction of the river course in the Lop Nur region at first using ArcGIS. Then the RCI index is constituted to extract ancient river course from Landsat ETM image with band 3 and band 4. It is concluded that the north river course of Peacock River conformed before the end of the 4th century AD according to the distribution of the entire river course of the Lop Nur region. Later, the Peacock River changed its way to south to Tarim River, and flowed into Lop Nur along the direction paralleling Altun Mountain from west to east. It was the change of the river system that mainly caused the decrease in water supply around ancient city of Loulan before the end of 4th century. The ancient city of Loulan has been gradually ruined in the sand because of the absence of water supply since then.

Diversity and Contributions to Nitrogen Cycling and Carbon Fixation of Soil Salinity Shaped Microbial Communities in Tarim Basin

PubMed Central

Ren, Min; Zhang, Zhufeng; Wang, Xuelian; Zhou, Zhiwei; Chen, Dong; Zeng, Hui; Zhao, Shumiao; Chen, Lingling; Hu, Yuanliang; Zhang, Changyi; Liang, Yunxiang; She, Qunxin; Zhang, Yi; Peng, Nan

2018-01-01

Arid and semi-arid regions comprise nearly one-fifth of the earth's terrestrial surface. However, the diversities and functions of their soil microbial communities are not well understood, despite microbial ecological importance in driving biogeochemical cycling. Here, we analyzed the geochemistry and microbial communities of the desert soils from Tarim Basin, northwestern China. Our geochemical data indicated half of these soils are saline. Metagenomic analysis showed that bacterial phylotypes (89.72% on average) dominated the community, with relatively small proportions of Archaea (7.36%) and Eukaryota (2.21%). Proteobacteria, Firmicutes, Actinobacteria, and Euryarchaeota were most abundant based on metagenomic data, whereas genes attributed to Proteobacteria, Actinobacteria, Euryarchaeota, and Thaumarchaeota most actively transcribed. The most abundant phylotypes (Halobacterium, Halomonas, Burkholderia, Lactococcus, Clavibacter, Cellulomonas, Actinomycetospora, Beutenbergia, Pseudomonas, and Marinobacter) in each soil sample, based on metagenomic data, contributed marginally to the population of all microbial communities, whereas the putative halophiles, which contributed the most abundant transcripts, were in the majority of the active microbial population and is consistent with the soil salinity. Sample correlation analyses according to the detected and active genotypes showed significant differences, indicating high diversity of microbial communities among the Tarim soil samples. Regarding ecological functions based on the metatranscriptomic data, transcription of genes involved in various steps of nitrogen cycling, as well as carbon fixation, were observed in the tested soil samples. Metatranscriptomic data also indicated that Thaumarchaeota are crucial for ammonia oxidation and Proteobacteria play the most important role in other steps of nitrogen cycle. The reductive TCA pathway and dicarboxylate-hydroxybutyrate cycle attributed to Proteobacteria and

Timing and Spatial Distribution of Loess in Xinjiang, NW China.

PubMed

Li, Yun; Song, Yougui; Yan, Libin; Chen, Tao; An, Zhisheng

2015-01-01

Central Asia is one of the most significant loess regions on Earth, with an important role in understanding Quaternary climate and environmental change. However, in contrast to the widely investigated loess deposits in the Chinese Loess Plateau, the Central Asian loess-paleosol sequences are still insufficiently known and poorly understood. Through field investigation and review of the previous literature, the authors have investigated the distribution, thickness and age of the Xinjiang loess, and analyzed factors that control these parameters in the Xinjiang in northwest China, Central Asia. The loess sediments cover river terraces, low uplands, the margins of deserts and the slopes of the Tianshan Mountains and Kunlun Mountains and are also present in the Ili Basin. The thickness of the Xinjiang loess deposits varies from several meters to 670 m. The variation trend of the sand fraction (>63 μm) grain-size contour can indicate the local major wind directions, so we conclude that the NW and NE winds are the main wind directions in the North and South Xinjiang, and the westerly wind mainly transport dust into the Ili basin. We consider persistent drying, adequate regional wind energy and well-developed river terraces to be the main factors controlling the distribution, thickness and formation age of the Xinjiang loess. The well-outcropped loess sections have mainly developed since the middle Pleistocene in Xinjiang, reflecting the appearance of the persistent drying and the present air circulation system. However, the oldest loess deposits are as old as the beginning of the Pliocene in the Tarim Basin, which suggests that earlier aridification occurred in the Tarim Basin rather than in the Ili Basin and the Junggar Basin.

An agricultural drought index to incorporate the irrigation process and reservoir operations: A case study in the Tarim River Basin

NASA Astrophysics Data System (ADS)

Li, Zehua; Hao, Zhenchun; Shi, Xiaogang; Déry, Stephen J.; Li, Jieyou; Chen, Sichun; Li, Yongkun

2016-08-01

To help the decision making process and reduce climate change impacts, hydrologically-based drought indices have been used to determine drought severity in the Tarim River Basin (TRB) over the past decades. As the major components of the surface water balance, however, the irrigation process and reservoir operations have not been incorporated into drought indices in previous studies. Therefore, efforts are needed to develop a new agricultural drought index, which is based on the Variable Infiltration Capacity (VIC) model coupled with an irrigation scheme and a reservoir module. The new drought index was derived from the simulated soil moisture data from a retrospective VIC simulation from 1961 to 2007 over the irrigated area in the TRB. The physical processes in the coupled VIC model allow the new agricultural drought index to take into account a wide range of hydrologic processes including the irrigation process and reservoir operations. Notably, the irrigation process was found to dominate the surface water balance and drought evolution in the TRB. Furthermore, the drought conditions identified by the new agricultural drought index presented a good agreement with the historical drought events that occurred in 1993-94, 2004, and 2006-07, respectively. Moreover, the spatial distribution of coupled VIC model outputs using the new drought index provided detailed information about where and to what extent droughts occurred.

Late Neoproterozoic paleomagnetic results from the Sugetbrak Formation of the Aksu area, Tarim basin (NW China) and their implications on the paleogeographic reconstruction and snowball Earth hypothesis

NASA Astrophysics Data System (ADS)

Zhan, S.; Chen, Y.; Xu, B.; Wang, B.; Faure, M.

2006-12-01

In order to better constrain the Neoproterozoic paleogeographic reconstruction of continents and improve the understanding of the snowball Earth hypothesis, paleomagnetic collections on Neoproterozoic rocks were carried out in the Aksu area of the northwestern Tarim basin from 2001 to 2005. Six sites of limestone from the Chigebrak formation, 38 sites of sandstone and 4 sites of volcanic rocks from the Sugetbrak formation were sampled. The remaining 24 sites of sandstone and volcanic rocks reveal stable characteristic remanent component (ChRm) isolated from 500 to 680? The computed magnetic directions from these components are relatively consistent and significantly distinguished from those of younger ages. Both normal and reverse polarities have been observed though the normal one is dominant, moreover, the positive fold test is revealed after bedding corrections at 95% confidence level. A paleomagnetic pole is, therefore, calculated: l =19.1? f =149.7? k = 11.2, A95 = 9.3?with n = 24, yielding a paleolatitude of ~27 for the sampling area. The chemostratigraphic correlation of this section with reference ones reveals an average of ~595 Ma for the age for this collection. Comparing paleomagnetic data of the similar ages from Australia and South China as well as other major blocks, the Tarim block seemed being closely located in the north of Australia. A new paleogeographic reconstruction has been attempted which showing a general feature of lower paleolatitude for these blocks. Referring to the paleogeographic reconstruction at about 760Ma proposed by Chen et al. (2004), the continental landmass including the above mentioned blocks seemed having experienced a relatively slow southward kinematic drift and kept their rather low paleolatitude. These observations provide, therefore, evidences to the snowball Earth hypothesis in the late Neoproterozoic time.

Temporal and spatial variations of precipitation in Northwest China during 1960-2013

NASA Astrophysics Data System (ADS)

Yang, Peng; Xia, Jun; Zhang, Yongyong; Hong, Si

2017-01-01

Based on the precipitation data from 96 weather stations in Northwest China (NWC) during 1960-2013, the Continuous Wavelet Transform (CWT) and the Mann-Kendall (MK) test were applied to analyze the precipitation spatiotemporal variations at different time scales. The relationships between the original precipitation and different periodic components were investigated. The results indicated that the annual precipitation was significantly increasing (P < 0.01) at the rate of 0.55 mm/a in the NWC. In terms of seasonal precipitation, the summer original precipitation significantly increased (P < 0.05) in the Southern Altay Mountain Basin (SAMB), Qaidam Basin (QB), Qiang Tang Plateau Basin (QTPB), Turpan-Hami Basin (THB), Tarim Desert Basin (TDB), Northern Tianshan Mountain Basin (NTMB) and NWC. For the winter original precipitation, except the Inner Mongolia Inland Rivers Basin and Northern Kunlun Mountain Basin, the significant increases (P < 0.05) were detected in the other sub-basins. In terms of monthly precipitation, significant increases were detected in January in the SAMB, NTMB and NWC, and July in the QB, Headstreams of Tarim River Basin (HTRB) and N. Additionally, most of the increasing and decreasing trends began in the mid-1980s or mid-1990s. Moreover, the periodic components were not always similar to the original data with the significant trends. The dominant scale of the original data from the periodic components was different in spatiotemporal distribution. Meanwhile, the relationship between the precipitation and El Niño-Southern Oscillation (ENSO) was different from period to period and from time scale to time scale. This study will help to develop better management measures to account for climate change and the supply/demand of water.

Wind erosion of cropland in the northwestern Tarim Basin

USDA-ARS?s Scientific Manuscript database

The Aksu region within the Tarim Basin is a major source of windblown dust due to aridity and vast areas under intensive irrigated crop production. Despite the importance of crop production to the local economy and sustenance, little is known about the amount of soil eroded by wind from agricultural...

The wheat R2R3-MYB transcription factor TaRIM1 participates in resistance response against the pathogen Rhizoctonia cerealis infection through regulating defense genes.

PubMed

Shan, Tianlei; Rong, Wei; Xu, Huijun; Du, Lipu; Liu, Xin; Zhang, Zengyan

2016-07-01

The necrotrophic fungus Rhizoctonia cerealis is a major pathogen of sharp eyespot that is a devastating disease of wheat (Triticum aestivum). Little is known about roles of MYB genes in wheat defense response to R. cerealis. In this study, TaRIM1, a R. cerealis-induced wheat MYB gene, was identified by transcriptome analysis, then cloned from resistant wheat CI12633, and its function and preliminary mechanism were studied. Sequence analysis showed that TaRIM1 encodes a R2R3-MYB transcription factor with transcription-activation activity. The molecular-biological assays revealed that the TaRIM1 protein localizes to nuclear and can bind to five MYB-binding site cis-elements. Functional dissection results showed that following R. cerealis inoculation, TaRIM1 silencing impaired the resistance of wheat CI12633, whereas TaRIM1 overexpression significantly increased resistance of transgenic wheat compared with susceptible recipient. TaRIM1 positively regulated the expression of five defense genes (Defensin, PR10, PR17c, nsLTP1, and chitinase1) possibly through binding to MYB-binding sites in their promoters. These results suggest that the R2R3-MYB transcription factor TaRIM1 positively regulates resistance response to R. cerealis infection through modulating the expression of a range of defense genes, and that TaRIM1 is a candidate gene to improve sharp eyespot resistance in wheat.

Magnetic minerals in three Asian rivers draining into the South China Sea: Pearl, Red, and Mekong Rivers

NASA Astrophysics Data System (ADS)

Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

2016-05-01

The use of the marine sedimentary magnetic properties, as tracers for changes in precipitation rate and in oceanic water masses transport and exchanges, implies to identify and to characterize the different sources of the detrital fraction. This is of particular importance in closed and/or marginal seas such as the South China Sea. We report on the magnetic properties of sedimentary samples collected in three main Asian rivers draining into the South China Sea: the Pearl, Red, and Mekong Rivers. The geological formations as well as the present climatic conditions are different from one catchment to another. The entire set of performed magnetic analyses (low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis parameters, FORC diagrams, and low-temperature magnetic measurements) allow us to identify the magnetic mineralogy and the grain-size distribution when magnetite is dominant. Some degree of variability is observed in each basin, illustrating different parent rocks and degree of weathering. On average it appears that the Pearl River is rich in magnetite along the main stream while the Mekong River is rich in hematite. The Red River is a mixture of the two. Compared to clay mineral assemblages and major element contents previously determined on the same samples, these new findings indicate that the magnetic fraction brings complementary information of great interest for environmental reconstructions based on marine sediments from the South China Sea.

Research on and Application to BH-HTC High Density Cementing Slurry System on Tarim Region

NASA Astrophysics Data System (ADS)

Yuanhong, Song; Fei, Gao; Jianyong, He; Qixiang, Yang; Jiang, Yang; Xia, Liu

2017-08-01

A large section of salt bed is contented in Tarim region Piedmont which constructs complex geological conditions. For high-pressure gas well cementing difficulties from the region, high density cement slurry system has been researched through reasonable level of particle size distribution and second weighting up. The results of laboratory tests and field applications show that the high density cementing slurry system is available to Tarim region cementing because this system has a well performance in slurry stability, gas breakthrough control, fluidity, water loss, and strength.

Early Development of Four Cyprinids Native to the Yangtze River, China

USGS Publications Warehouse

Chapman, Duane C.

2006-01-01

Chapter 1 -- Notes on the Translation and Use of "A Study of the Early Development of Grass Carp, Black Carp, Silver Carp, and Bighead Carp in the Yangtze River, China" By Duane C. Chapman and Ning Wang Chapter 2 -- A Study of the Early Development of Grass Carp, Black Carp, Silver Carp, and Bighead Carp in the Yangtze River, China By Bolu Yi, Zhishen Liang, Zhitang Yu, Randuan Lin, and Mingjue HeTranslated by Duane C. Chapman and Ning Wang The document A Study of the Early Development of Grass Carp, Black Carp, Silver Carp, and Bighead Carp in the Yangtze River, China (Chapter 2 of this volume) was translated from the Chinese with the approval and assistance of the living authors of that study. It contains the most detailed description available, and approximately 200 drawings, of the early development of the subject fishes. Chapter 1 provides important instructions on the use of the translation, including a description of the Chinese morphometric conventions, which differ from those used by North American scientists. Chapter 1 also provides the historical context in which Chapter 2 was developed, and information on how the larvae of the subject fishes, which have invaded the Mississippi River basin, may be distinguished from other fishes present in the basin.

The wheat R2R3-MYB transcription factor TaRIM1 participates in resistance response against the pathogen Rhizoctonia cerealis infection through regulating defense genes

PubMed Central

Shan, Tianlei; Rong, Wei; Xu, Huijun; Du, Lipu; Liu, Xin; Zhang, Zengyan

2016-01-01

The necrotrophic fungus Rhizoctonia cerealis is a major pathogen of sharp eyespot that is a devastating disease of wheat (Triticum aestivum). Little is known about roles of MYB genes in wheat defense response to R. cerealis. In this study, TaRIM1, a R. cerealis-induced wheat MYB gene, was identified by transcriptome analysis, then cloned from resistant wheat CI12633, and its function and preliminary mechanism were studied. Sequence analysis showed that TaRIM1 encodes a R2R3-MYB transcription factor with transcription-activation activity. The molecular-biological assays revealed that the TaRIM1 protein localizes to nuclear and can bind to five MYB-binding site cis-elements. Functional dissection results showed that following R. cerealis inoculation, TaRIM1 silencing impaired the resistance of wheat CI12633, whereas TaRIM1 overexpression significantly increased resistance of transgenic wheat compared with susceptible recipient. TaRIM1 positively regulated the expression of five defense genes (Defensin, PR10, PR17c, nsLTP1, and chitinase1) possibly through binding to MYB-binding sites in their promoters. These results suggest that the R2R3-MYB transcription factor TaRIM1 positively regulates resistance response to R. cerealis infection through modulating the expression of a range of defense genes, and that TaRIM1 is a candidate gene to improve sharp eyespot resistance in wheat. PMID:27364458

Emission estimation and multimedia fate modeling of seven steroids at the river basin scale in China.

PubMed

Zhang, Qian Qian; Zhao, Jian-Liang; Ying, Guang-Guo; Liu, You-Sheng; Pan, Chang-Gui

2014-07-15

Steroids are excreted from humans and animals and discharged with wastewaters into the environment, resulting in potential adverse effects on organisms. Based on the excretion rates from different groups of humans and animals, the emissions of seven steroids (estrone (E1), 17β-estradiol (E2), estriol (E3), testosterone (T), androsterone (A), progesterone (P), and cortisol (C)) were comprehensively estimated in 58 river basins of whole China, and their multimedia fate was simulated by using a level III fugacity multimedia model. The results showed that higher emission densities for the steroids were found in the river basins of east China than in west China. This distribution was found to be generally similar to the distribution of Gross Domestic Product (GDP) across China. E3, A, and P displayed higher emission densities than the other steroids in most of the river basins. The total excretion of steroids by humans and animals in China was estimated to be 3069 t/yr. The excretion of steroids from animals was two times larger than that from humans. After various treatments, the total emission of steroids was reduced to 2486 t/yr, of which more than 80% was discharged into the water compartment. The predicted concentrations in water were within an order of magnitude of the measured concentrations available in the literature. Owing to wastewater irrigation, more steroid mass loadings in agricultural soil were found in the basins of Haihe River and Huaihe River in comparison with the other river basins. To the best of our knowledge, this is the first report on the emissions and multimedia fate of seven steroids in the river basins of China.

Characterizing Air Temperature Changes in the Tarim Basin over 1960–2012

PubMed Central

Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

2014-01-01

There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960–2012, and analyzed annual mean temperature (AMT), the annual minimum (Tmin) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the Tmin (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from −0.09 to 0.43 °C/10a) and Tmin (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with Tmin and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960–1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales. PMID

Model identification and control of development of deeply buried paleokarst reservoir in the central Tarim Basin, northwest China

NASA Astrophysics Data System (ADS)

Yu, Jingbo; Li, Zhong; Yang, Liu; Han, Yinxue

2018-04-01

The paleokarst reservoirs of the Ordovician Yingshan formation, rich in oil and gas, are deeply buried in the central Tarim Basin, northwest China. Dozens of imaging well-logs in this region reveal five typical paleokarst features, including solution vugs, solution-enlarged fractures, filled caves, unfilled caves and collapsed caves, as well as two typical paleokarst structures located in different paleotopographic sites, including paleokarst vadose and phreatic zones. For seismic data, the large wave impedance contrast between the paleocave system and the surrounding rocks leads to a strong seismic reflection, which is highlighted as a bead-like ‘bright spot’ in a seismic section. By quantitatively estimating the seismic resolution limits of deep seismic reflections, a single paleocave cannot be identified from a seismic profile, and the bead-like reflection represents an entire paleocave complex. The spectral decomposition technique was employed to depict the planar shape and semi-quantitatively measure the size of the paleocave complexes. The results indicate that the sizes of the paleokarst caves are all small, and most of the karst caves are nearly completely filled by clay and calcite. The small cave size and the effective support of cave fills for the overlying strata mean that some individual paleocaves in a paleocave complex are preserved at a burial depth of more than 6000 m. Paleotopography and faults strongly impact the distribution of paleokarst reservoirs. Well-developed paleokarst reservoirs are generally located in paleotopographic highlands and on slopes, and for a specific paleotopographic site, the distribution of paleokarst reservoirs is obviously controlled by NW-SE trending faults. The most favorable area for paleokarst development is the Tazhong No. 10 fault zone, a faulted anticline bounded by two NW-SE trending back thrusts.

Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age

PubMed Central

2010-01-01

Background The Tarim Basin, located on the ancient Silk Road, played a very important role in the history of human migration and cultural communications between the West and the East. However, both the exact period at which the relevant events occurred and the origins of the people in the area remain very obscure. In this paper, we present data from the analyses of both Y chromosomal and mitochondrial DNA (mtDNA) derived from human remains excavated from the Xiaohe cemetery, the oldest archeological site with human remains discovered in the Tarim Basin thus far. Results Mitochondrial DNA analysis showed that the Xiaohe people carried both the East Eurasian haplogroup (C) and the West Eurasian haplogroups (H and K), whereas Y chromosomal DNA analysis revealed only the West Eurasian haplogroup R1a1a in the male individuals. Conclusion Our results demonstrated that the Xiaohe people were an admixture from populations originating from both the West and the East, implying that the Tarim Basin had been occupied by an admixed population since the early Bronze Age. To our knowledge, this is the earliest genetic evidence of an admixed population settled in the Tarim Basin. PMID:20163704

Aerodynamic properties of agricultural and natural surfaces in northwestern Tarim Basin

USDA-ARS?s Scientific Manuscript database

Friction velocity (u*) and aerodynamic roughness (z0) are important parameters that influence soil erosion, but no attempts have been made to quantify these parameters as affected by different land use types in the northwestern Tarim Basin. Wind velocity profiles were measured and used to determine ...

Kink-style detachment folding in Bachu fold belt of central Tarim Basin, China: geometry and seismic interpretation

NASA Astrophysics Data System (ADS)

Bo, Zhang; Jinjiang, Zhang; Shuyu, Yan; Jiang, Liu; Jinhai, Zhang; Zhongpei, Zhang

2010-05-01

The phenomenon of Kink banding is well known throughout the engineering and geophysical sciences. Associated with layered structures compressed in a layer-parallel direction, it arises for example in stratified geological systems under tectonic compression. Our work documented it is also possible to develop super large-scale kink-bands in sedimentary sequences. We interpret the Bachu fold uplift belt of the central Tarim basin in western China to be composed of detachment folds flanked by megascopic-scale kink-bands. Those previous principal fold models for the Bachu uplift belt incorporated components of large-scale thrust faulting, such as the imbricate fault-related fold model and the high-angle, reverse-faulted detachment fold model. Based on our observations in the outcrops and on the two-dimension seismic profiles, we interpret that first-order structures in the region are kink-band style detachment folds to accommodate regional shortening, and thrust faulting can be a second-order deformation style occurring on the limb of the detachment folds or at the cores of some folds to accommodate the further strain of these folds. The belt mainly consists of detachment folds overlying a ductile decollement layer. The crests of the detachment folds are bounded by large-scale kink-bands, which are zones of angularly folded strata. These low-signal-tonoise, low-reflectivity zones observed on seismic profiles across the Bachu belt are poorly imaged sections, which resulted from steeply dipping bedding in the kink-bands. The substantial width (beyond 200m) of these low-reflectivity zones, their sub-parallel edges in cross section, and their orientations at a high angle to layering between 50 and 60 degrees, as well as their conjugate geometry, support a kink-band interpretation. The kink-band interpretation model is based on the Maximum Effective Moment Criteria for continuous deformation, rather than Mohr-Column Criteria for brittle fracture. Seismic modeling is done to

Assessment of River Habitat Quality in the Hai River Basin, Northern China.

PubMed

Ding, Yuekui; Shan, Baoqing; Zhao, Yu

2015-09-17

We applied a river habitat quality (RHQ) assessment method to the Hai River Basin (HRB); an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 10⁴ km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 10⁴ km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m); lower coverage of riparian vegetation (≤40%); artificial land use patterns (public and industrial land); frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m³); single flow channels; and rare aquatic plants (≤1 category). At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p < 0.01) and urban land (r = 0.998; p < 0.05); and was significantly and positively correlated with grassland and woodland (r = 1.000; p < 0.01). Intensive artificial land use; created through urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08-16.56); caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated.

Assessment of River Habitat Quality in the Hai River Basin, Northern China

PubMed Central

Ding, Yuekui; Shan, Baoqing; Zhao, Yu

2015-01-01

We applied a river habitat quality (RHQ) assessment method to the Hai River Basin (HRB); an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 104 km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 104 km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m); lower coverage of riparian vegetation (≤40%); artificial land use patterns (public and industrial land); frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m3); single flow channels; and rare aquatic plants (≤1 category). At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p < 0.01) and urban land (r = 0.998; p < 0.05); and was significantly and positively correlated with grassland and woodland (r = 1.000; p < 0.01). Intensive artificial land use; created through urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08–16.56); caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated. PMID:26393628

An Integrated Decision Support System with Hydrological Processes and Socio-economic Assessments

NASA Astrophysics Data System (ADS)

Yu, Yang; Disse, Markus; Yu, Ruide

2017-04-01

The debate over the effectiveness of Integrated Water Resources Management (IWRM) in practice has lasted for years. As the complexity and scope of IWRM increases, the difficulties of hydrological modeling is shifting from the model itself into the links with other cognate sciences, to understand the interactions among water, earth, ecosystem and humans. This work presents the design and development of a decision support system (DSS) that links the outputs of hydrological models with real-time decision making on social-economic assessments and land use changes. Discharge and glacier geometry changes were simulated with hydrological model WASA. Irrigation and ecological water were simulated by a new commercial software MIKE HYDRO. Groundwater was simulated by MODFLOW. All the outputs of theses hydrological models were integrated as inputs into the DSS in three types of links: regression equations, stationary data inputs, or dynamic data inputs into DSS as the models running parallel in the simulation periods. Within DSS, three types of logics were established: equations, conditional statements and fuzzy logics. The programming was realized in C++. The implementation of DSS takes place in the Tarim River Basin. With the mainstream of 1,321km and located in an arid area in northwest China, the Tarim River is China's longest inland river. The Tarim basin on the northern edge of the Taklamakan desert is an extremely arid region. In this region, agricultural water consumption and allocation management are crucial to address the conflicts among irrigation water users from upstream to downstream. Since 2011, the German Ministry of Science and Education BMBF established the Sino-German SuMaRiO project, for the sustainable management of river oases along the Tarim River. Project SuMaRiO focus on realizable management strategies, considering social, economic and ecological criteria. This will have positive effects for nearly 10 million inhabitants of different ethnic groups

[Estimation of desert vegetation coverage based on multi-source remote sensing data].

PubMed

Wan, Hong-Mei; Li, Xia; Dong, Dao-Rui

2012-12-01

Taking the lower reaches of Tarim River in Xinjiang of Northwest China as study areaAbstract: Taking the lower reaches of Tarim River in Xinjiang of Northwest China as study area and based on the ground investigation and the multi-source remote sensing data of different resolutions, the estimation models for desert vegetation coverage were built, with the precisions of different estimation methods and models compared. The results showed that with the increasing spatial resolution of remote sensing data, the precisions of the estimation models increased. The estimation precision of the models based on the high, middle-high, and middle-low resolution remote sensing data was 89.5%, 87.0%, and 84.56%, respectively, and the precisions of the remote sensing models were higher than that of vegetation index method. This study revealed the change patterns of the estimation precision of desert vegetation coverage based on different spatial resolution remote sensing data, and realized the quantitative conversion of the parameters and scales among the high, middle, and low spatial resolution remote sensing data of desert vegetation coverage, which would provide direct evidence for establishing and implementing comprehensive remote sensing monitoring scheme for the ecological restoration in the study area.

Evaluation of ecological instream flow considering hydrological alterations in the Yellow River basin, China

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Zhang, Zongjiao; Shi, Peijun; Singh, Vijay P.; Gu, Xihui

2018-01-01

The Yellow River is the second largest river in China and is the important source for water supply in the northwestern and northern China. It is often regarded as the mother river of China. Owing to climatic change and intensifying human activities, such as increasing withdrawal of water for meeting growing agricultural irrigation needs since 1986, the flow of Yellow River has decreased, with serious impacts on the ecological environment. Using multiple hydrological indicators and Flow Duration Curve (DFC)-based ecodeficit and ecosurplus, this study investigates the impact of hydrological alterations, such as the impact of water reservoirs or dams, on downstream ecological instream flow. Results indicate that: (1) due to the impoundment and hydrological regulations of water reservoirs, occurrence rates and magnitudes of high flow regimes have decreased and the decrease is also found in the magnitudes of low flow events. These changes tend to be more evident from the upper to the lower Yellow River basin; (2) human activities tend to enhance the instream flow variability, particularly after the 1980s;(3) the ecological environment in different parts of the Yellow River basin is under different degrees of ecological risk. In general, lower to higher ecological risk can be detected due to hydrological alterations from the upper to the lower Yellow River basin. This shows that conservation of ecological environment and river health is facing a serious challenge in the lower Yellow River basin; (4) ecological instream flow indices, such as ecodeficit and ecosurplus, and IHA32 hydrological indicators are in strong relationships, suggesting that ecodeficit and ecosurplus can be regarded as appropriate ecological indicators for developing measures for mitigating the adverse impact of human activities on the conservation of ecological environment in the Yellow River basin.

Monitoring the spatio-temporal changes of terrestrial water storage using GRACE data in the Tarim River basin between 2002 and 2015.

PubMed

Yang, Peng; Xia, Jun; Zhan, Chesheng; Qiao, Yunfeng; Wang, Yueling

2017-10-01

With the threat of water shortages intensifying, the need to identify the terrestrial water storage (TWS) variation in the Tarim River Basin (TRB) becomes very significant for managing its water resource. Due to the lack of large-scale hydrological data, this study employed the Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) to monitor TWS variation in the TRB during the period of 2002-2015, cooperating with two statistical techniques, Principal Component Analysis (PCA) - Empirical Orthogonal Function (EOF) and Multiple Linear Regression (MLR). Results indicated that (1) the Tropical rainfall measuring mission (TRMM) data can be applied well in the TRB; (2) the EOF result showed that both the time series of TRMM precipitation and GRACE-derived TWS in the TRB between 2002 and 2015 were dominated by the annual signals, which were followed by the semiannual signals; (3) the linear trend for the spatially averaged GRACE-derived TWS changes exhibited an decrease of 1.6±1.1mm/a, and the EOF result indicated a significant decrease of 4.1±1.5mm/a in the north of TRB; (4) while the precipitation variations was the major driver for the TWS changes, the GLDAS-derived TWS (i.e., soil moisture) decrease and ground water decrease played the major role in the TWS decrease in the north of TRB for the significant correlation (P<0.05). The changes of TWS might be linked to excessive exploitation of water resources, increased population, and shrinking water supplies, which would impact on the water level of the lakes or reservoir. Copyright © 2017 Elsevier B.V. All rights reserved.

Petrogenesis of nephelinites from the Tarim Large Igneous Province, NW China: Implications for mantle source characteristics and plume-lithosphere interaction

NASA Astrophysics Data System (ADS)

Cheng, Zhiguo; Zhang, Zhaochong; Hou, Tong; Santosh, M.; Zhang, Dongyang; Ke, Shan

2015-04-01

The nephelinite exposed in the Wajilitage area in the northwestern margin of the Tarim large igneous province (TLIP), Xinjiang, NW China display porphyritic textures with clinopyroxene, nepheline and olivine as the major phenocryst phases, together with minor apatite, sodalite and alkali feldspar. The groundmass typically has cryptocrystalline texture and is composed of crystallites of clinopyroxene, nepheline, Fe-Ti oxides, sodalite, apatite, rutile, biotite, amphibole and alkali feldspar. We report rutile SIMS U-Pb age of 268 ± 30 Ma suggesting that the nephelinite may represent the last phase of the TLIP magmatism, which is also confirmed by the field relation. The nephelinite shows depleted Sr-Nd isotopic compositions with age-corrected 87Sr/86Sr and εNd(t) values of 0.70348-0.70371 and + 3.28 to + 3.88 respectively indicating asthenospheric mantle source. Based on the reconstructed primary melt composition, the depth of magma generation is estimated as 115-140 km and the temperatures of mantle melting as 1540-1575 °C. The hotter than normal asthenospheric mantle temperature suggests the involvement of mantle thermal plume. The Mg isotope values display a limited range of δ26Mg from - 0.35 to - 0.55‰, which are lower than the mantle values (- 0.25‰). The Mg isotopic compositions, combined with the Sr-Nd isotopes and major and trace element data suggest that the Wajilitage nephelinite was most likely generated by low-degree partial melting of the hybridized carbonated peridotite/eclogite source, which we correlate with metasomatism by subducted carbonates within the early-middle Paleozoic convergent regime. A plume-lithosphere model is proposed with slight thinning of the lithosphere and variable depth and degree of melting of the carbonated mantle during the plume-lithosphere interaction. This model also accounts for the variation in lithology of the TLIP.

Comparing bias correction methods in downscaling meteorological variables for a hydrologic impact study in an arid area in China

NASA Astrophysics Data System (ADS)

Fang, G. H.; Yang, J.; Chen, Y. N.; Zammit, C.

2015-06-01

Water resources are essential to the ecosystem and social economy in the desert and oasis of the arid Tarim River basin, northwestern China, and expected to be vulnerable to climate change. It has been demonstrated that regional climate models (RCMs) provide more reliable results for a regional impact study of climate change (e.g., on water resources) than general circulation models (GCMs). However, due to their considerable bias it is still necessary to apply bias correction before they are used for water resources research. In this paper, after a sensitivity analysis on input meteorological variables based on the Sobol' method, we compared five precipitation correction methods and three temperature correction methods in downscaling RCM simulations applied over the Kaidu River basin, one of the headwaters of the Tarim River basin. Precipitation correction methods applied include linear scaling (LS), local intensity scaling (LOCI), power transformation (PT), distribution mapping (DM) and quantile mapping (QM), while temperature correction methods are LS, variance scaling (VARI) and DM. The corrected precipitation and temperature were compared to the observed meteorological data, prior to being used as meteorological inputs of a distributed hydrologic model to study their impacts on streamflow. The results show (1) streamflows are sensitive to precipitation, temperature and solar radiation but not to relative humidity and wind speed; (2) raw RCM simulations are heavily biased from observed meteorological data, and its use for streamflow simulations results in large biases from observed streamflow, and all bias correction methods effectively improved these simulations; (3) for precipitation, PT and QM methods performed equally best in correcting the frequency-based indices (e.g., standard deviation, percentile values) while the LOCI method performed best in terms of the time-series-based indices (e.g., Nash-Sutcliffe coefficient, R2); (4) for temperature, all

Suitability Evaluation on River Bank Filtration of the Second Songhua River, China

NASA Astrophysics Data System (ADS)

Wang, Lixue; Ye, Xueyan; Du, Xinqiang

2016-04-01

The Second Songhua River is the biggest river with the most economic value in Jilin Province, China. In recent years, with the rapid development of economy, water resources and water environment problem is getting prominent, including surface water pollution and over exploitation of groundwater resources, etc. By means of bank filtration, the Second Songhua River basin might realize the combined utilization of regional groundwater and surface water, and thus has important significance for the guarantee of water demand for industrial and agricultural production planning in the basin. The following steps were adopted to evaluate the suitability of bank filtration nearby the Scond Songhua River : Firstly, in order to focus on the most possible area, the evaluation area was divided based on the aspects of natural geographical conditions and hydraulic connection extent between river water and groundwater. Second, the main suitability indexes including water quantity, water quality, interaction intensity between surface water and groundwater, and the exploitation condition of groundwater resource, and nine sub-indexes including hydraulic conductivity, aquifer thickness, river runoff, the status of groundwater quality, the status of surface water quality, groundwater hydraulic gradient, possible influence zone width of surface water under the condition of groundwater exploitation, permeability of riverbed layer and groundwater depth were proposed to establish an evaluation index system for the suitability of river bank filtration. Thirdly, Combined with the natural geography, geology and hydrogeology conditions of the Second Songhua River basin, the ArcGIS technology is used to complete the evaluation of the various indicators. According to the weighted sum of each index, the suitability of river bank filtration in the study area is divided into five grades. The evaluation index system and evaluation method established in this article are applicable to the Second Songhua

Monitoring potential geographical distribution of four wild bird species in China

NASA Astrophysics Data System (ADS)

Dai, S.; Feng, D.; Xu, B.

2015-12-01

The outbreak of highly pathogenic avian influenza (HPAI) of the H5N1 subtype in wild birds and poultry have caught worldwide attention. To explore the association between wild bird migration and avian influenza virus transmission, we monitored potential geographical distribution of four wild bird species that might carry the avian influenza viruses in China. They are Bar-headed geese (Anser indicus), Ruddy Shelduck (Tadorna ferruginea), Whooper Swan (Cygnus cygnus) and Black-headed Gull (Larus ridibundus). They served as major reservoir of the avian influenza viruses. We used bird watching records with the precise latitude/longitude coordinates from January 2002 to August 2014, and environmental variables with a pixel resolution of 5 km × 5 km from 2002 to 2014. The study utilized maximum entropy (MaxEnt) model based on ecological niche model approaches, and got the following results: 1) MaxEnt model have good discriminatory ability with the area under the curve (AUC) of the receiver operating curve (ROC) of 0.86-0.97; 2) The four wild bird species were estimated to concentrate in the North China Plain, the middle and lower region of the Yangtze River, Qinghai Lake, Tianshan Mountain and Tarim Basin, part of Tibet Plateau, and Hengduan Mountains; 3) Radiation and the minimum temperature were found to provide the most significant information. Our findings will help to understand the spread of avian influenza viruses by wild bird migration in China, which benefits for effective monitoring strategies and prevention measures.

Evaluation of two empirical wind erosion models in arid and semi-arid regions of China and the USA

USDA-ARS?s Scientific Manuscript database

The Tarim Basin in China and Columbia Plateau in the USA are important agricultural regions as well as source regions of windblown dust that impact air quality in Asia and North America. Wind erosion models are important tools for assessing the potential erodibility of soils and best management prac...

Human-induced hydrologic and geomorphic changes in the crisscross river network of the Pearl River Delta, South China

NASA Astrophysics Data System (ADS)

Chen, Y. D.; Chen, X. H.

2003-04-01

The West River, the North River and the East River, collectively called the Pearl River, have a total drainage area of 453,690 km2 in southern and southwestern China and flow into the South China Sea. The three rivers join together and form the Pearl River Delta (PRD) with an area of 26,820 km2. The crisscross river network (density: 0.68-1.07 km/km2) in the PRD is one of the most complicated deltaic drainage systems in the world. As the region experiencing the most rapid economic growth in China over the past two decades, the PRD has witnessed massive changes in both the social and the natural environment, leading to an urgent need of studying regional environmental changes caused by intensive human activities. This paper aims to summarize and illustrate a variety of human-induced hydrologic and geomorphic changes in the PRD river network and to present an analysis of the causes and effects of these changes. Findings of this study will help decision-makers to formulate river management and mitigation strategies and policies in the region. The hydrologic characteristics of the PRD river network have been altered to varying degrees in the following three main aspects. First and most importantly, stage has become higher or lower over the past several decades in an uneven manner in different parts of the delta. From the early 1950s to the 1980s, scattered and small embankments were enlarged and combined to expand land mass and reduce flood hazards in the PRD. However, reduction of water surface area and concentration of flow into major channels generally caused stage to go up slightly. Since the early 1990s, stage in the upper part of the PRD has significantly dropped down while the opposite situation has become more and more common in the central PRD where enormous flood damages have occurred. Secondly, corresponding to the stage changes, the stage-discharge relationship has been substantially modified, as evidenced by over 2 m drop of stage for the same amount of

Spatiotemporal characteristics of organic contaminant concentrations and ecological risk assessment in the Songhua River, China

EPA Science Inventory

To control source pollution and improve water quality, an understanding of the spatiotemporal characteristics of organic contaminant concentrations in affected receiving waters is necessary. The Songhua River in northeast China is the country's third-largest domestic river and lo...

Heavy metal contamination status and source apportionment in sediments of Songhua River Harbin region, Northeast China.

PubMed

Li, Ning; Tian, Yu; Zhang, Jun; Zuo, Wei; Zhan, Wei; Zhang, Jian

2017-02-01

The Songhua River represents one of the seven major river systems in China. It flows through Harbin city with 66 km long, locating in the northern China with a longer winter time. This paper aimed to study concentration distributions, stability, risk assessment, and source apportionment of heavy metals including chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), and nickel (Ni) in 11 selected sections of the Songhua River Harbin region. Results showed that Cr, Cd, Pb, Hg, and As exceeded their respective geochemical background values in sediments of most monitoring sections. Compared with other important rivers and lakes in China, Cr, Hg, Cd, and As pollutions in surface sediments were above medium level. Further analysis of chemical speciation indicated that Cr and As in surface sediments were relatively stable while Pb and Cd were easily bioavailable. Correlation analysis revealed sources of these metals except As might be identical. Pollution levels and ecological risks of heavy metals in surface sediments presented higher in the mainstream region (45° 47.0' N ~ 45° 53.3' N, 126° 37.0' E ~ 126° 42.1' E). Source apportionment found Hejiagou and Ashi River were the main contributors to metal pollution of this region. Thus, anthropogenic activities along the Hejiagou and Ashi River should be restricted in order to protect the Songhua River Harbin region from metal contamination.

Occurrence of polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls pollution in sediments from the Haihe River and Dagu Drainage River in Tianjin City, China.

PubMed

Liu, Hanxia; Zhang, Qinghua; Wang, Yawei; Cai, Zongwei; Jiang, Guibin

2007-08-01

The pollution status of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in the sediments of Haihe River, which is the most polluted among the seven largest basins in China, Dagu Drainage River flowing through a chemical industry zone, and two other rivers flowing into Bohai Sea in Tianjin City, China were investigated. The concentrations of PCDD/Fs and PCBs in the sediments from the mainstream of Haihe River were 1.3-26pgI-TEQg(-1) dry weight (dw) and 0.07-0.54pgTEQg(-1)dw, respectively. Heavy PCDD/Fs and PCBs pollution, with 1264pgI-TEQg(-1)dw and 21pgTEQg(-1)dw, was found in sediment from Dagu Drainage River. The congener profiles of PCDD/Fs indicated that the principal contamination source was the production of pentachlorophenol (PCP) or PCP-Na in this area. The correlation between PCDD/Fs or PCBs and total organic matter (TOM) showed that PCDD/Fs or PCBs were independent on TOM.

Simulation of blue and green water resources in the Wei River basin, China

NASA Astrophysics Data System (ADS)

Xu, Z.; Zuo, D.

2014-09-01

The Wei River is the largest tributary of the Yellow River in China and it is suffering from water scarcity and water pollution. In order to quantify the amount of water resources in the study area, a hydrological modelling approach was applied by using SWAT (Soil and Water Assessment Tool), calibrated and validated with SUFI-2 (Sequential Uncertainty Fitting program) based on river discharge in the Wei River basin (WRB). Sensitivity and uncertainty analyses were also performed to improve the model performance. Water resources components of blue water flow, green water flow and green water storage were estimated at the HRU (Hydrological Response Unit) scales. Water resources in HRUs were also aggregated to sub-basins, river catchments, and then city/region scales for further analysis. The results showed that most parts of the WRB experienced a decrease in blue water resources between the 1960s and 2000s, with a minimum value in the 1990s. The decrease is particularly significant in the most southern part of the WRB (Guanzhong Plain), one of the most important grain production basements in China. Variations of green water flow and green water storage were relatively small on the spatial and temporal dimensions. This study provides strategic information for optimal utilization of water resources and planning of cultivating seasons in the Wei River basin.

Microfacies and depositional environments of the Late Ordovician Lianglitage Formation at the Tazhong Uplift in the Tarim Basin of Northwest China

NASA Astrophysics Data System (ADS)

Gao, Da; Lin, Changsong; Yang, Haijun; Zuo, Fanfan; Cai, Zhenzhong; Zhang, Lijuan; Liu, Jingyan; Li, Hong

2014-04-01

The Late Ordovician Lianglitage Formation comprises 13 microfacies (Mf1-Mf13) that were deposited on a carbonate platform at the Tazhong Uplift of the Tarim Basin in Northwest China. Each type of microfacies indicates a specific depositional environment with a certain level of wave energy. Four primary groups of microfacies associations (MA1-MA4) were determined. These associations represent different depositional facies, including reef-shoal facies in the platform margin (MA1), carbonate sand shoal facies (MA2) and oncoid shoal (MA3) on open platforms, and lagoon and tidal flat facies (MA4) in the platform interior. Each microfacies association was generated in a fourth-order sedimentary sequence developing within third-order sequences (SQ1, SQ2, and SQ3, from bottom to top), showing a shallowing-upward trend. High-frequency sequences and facies correlation between wells suggests that the reef-shoal facies more successively developed in the southeastern part of the platform margin, and high-energy microfacies were more strictly confined by the top boundary of fourth-order sequences in the northwestern part of the platform. The highstand systems tract (HST) of the SQ2 is characterized by reef-shoals that developed along the platform margin and tidal flats and lagoons that developed in the platform interior, while the SQ3 is characterized by the oncoid shoal facies that generally developed on the uplift due to a regionally extensive transgression that occurred during the latter part of the Late Ordovician. The results of this study can be used for investigating the development and distribution of potential reservoirs; the reservoirs in southeastern part of the platform margin may be of premium quality because the high-energy microfacies were best preserved there.

Landsat and SPOT data for oil exploration in North-Western China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishidai, Takashi

1996-07-01

Satellite remote sensing technology has been employed by Japex to provide information related to oil exploration programs for many years. Since the beginning of the 1980`s, regional geological interpretation through to advanced studies using satellite imagery with high spectral and spatial resolutions (such as Landsat TM and SPOT HRV), have been carried out, for both exploration programs and for scientific research. Advanced techniques (including analysis of airborne hyper-multispectral imaging sensor data) as well as conventional photogeological techniques were used throughout these programs. The first program using remote sensing technology in China focused on the Tarim Basin, Xinjiang Uygur Autonomous Region,more » and was carried out using Landsat MSS data. Landsat MSS imagery allows us to gain useful preliminary geological information about an area of interest, prior to field studies. About 90 Landsat scenes cover the entire Xinjiang Uygru Autonomous Region, this allowed us to give comprehensive overviews of 3 hydrocarbon-bearing basins (Tarim, Junggar, and Turpan-Hami) in NW China. The overviews were based on the interpretations and assessments of the satellite imagery and on a synthesis of the most up-to-date accessible geological and geophysical data as well as some field works. Pairs of stereoscopic SPOT HRV images were used to generate digital elevation data with a 40 in grid cover for part of the Tarim Basin. Topographic contour maps, created from this digital elevation data, at scales of 1:250,000 and 1:100,000 with contour intervals of 100 m and 50 m, allowed us to make precise geological interpretation, and to carry out swift and efficient geological field work. Satellite imagery was also utilized to make medium scale to large scale image maps, not only to interpret geological features but also to support field workers and seismic survey field operations.« less

Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

NASA Astrophysics Data System (ADS)

Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

2017-11-01

Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

Projection of actual evapotranspiration using the COSMO-CLM regional climate model under global warming scenarios of 1.5 °C and 2.0 °C in the Tarim River basin, China

NASA Astrophysics Data System (ADS)

Su, Buda; Jian, Dongnan; Li, Xiucang; Wang, Yanjun; Wang, Anqian; Wen, Shanshan; Tao, Hui; Hartmann, Heike

2017-11-01

Actual evapotranspiration (ETa) is an important component of the water cycle. The goals for limiting global warming to below 2.0 °C above pre-industrial levels and aspiring to 1.5 °C were negotiated in the Paris Agreement in 2015. In this study, outputs from the regional climate model COSMO-CLM (CCLM) for the Tarim River basin (TRB) were used to calculate ETa with an advection-aridity model, and changes in ETa under global warming scenarios of 1.5 °C (2020 to 2039) and 2.0 °C (2040 to 2059) were analyzed. Comparison of warming at the global and regional scale showed that regional 1.5 °C warming would occur later than the global average, while regional 2.0 °C warming would occur earlier than the global average. For global warming of 1.5 °C, the average ETa in the TRB is about 222.7 mm annually, which represents an increase of 6.9 mm relative to the reference period (1986-2005), with obvious increases projected for spring and summer. The greatest increases in ETa were projected for the northeast and southwest. The increment in the annual ETa across the TRB considering a warming of 1.5 °C was 4.3 mm less than that for a warming of 2.0 °C, and the reduction between the two levels of warming was most pronounced in the summer, when ETa was 3.4 mm smaller. The reduction in the increment of annual ETa for warming of 1.5 °C relative to warming of 2.0 °C was most pronounced in the southwest and northeast, where it was projected to be 8.2 mm and 9.3 mm smaller, respectively. It is suggested that the higher ETa under a warming of 2.0 °C mainly results from an increase in the sunshine duration (net radiation) in the southwestern basin and an increase in precipitation in the northeastern basin. Vapor is removed from the limited surface water supplies by ETa. The results of this study are therefore particularly relevant for water resource planning in the TRB.

Fluoroquinolones in the Wenyu River catchment, China: Occurrence simulation and risk assessment.

PubMed

Hao, Xuewen; Cao, Yan; Zhang, Lai; Zhang, Yongyong; Liu, Jianguo

2015-12-01

Concern is increasing regarding the environmental impact of the high usage rate and intensive release of antibiotics used for human and animal therapy in major urban areas of China. In the present study, regional environmental distribution simulations and risk assessments for 3 commonly used fluoroquinolones in the Wenyu River catchment were conducted using a typical catchment model widely used in Europe. The fluoroquinolone antibiotics investigated (ofloxacin, norfloxacin, and ciprofloxacin) are consumed at high levels for personal health care in China. These antibiotics were simulated in the aquatic environment of the Wenyu River catchment across the Beijing City area for annual average concentrations, with regional predicted environmental concentrations (PECs) of approximately 711 ng/L, 55.3 ng/L, and 22.2 ng/L and local PECs up to 1.8 µg/L, 116 ng/L, and 43 ng/L, respectively. Apart from hydrological conditions, the concentrations of fluoroquinolones were associated closely with the sewage treatment plants (STPs) and their serving population, as well as hospital distributions. The presence of these fluoroquinolones in the catchment area of the present study showed significant characteristics of the occurrence of pharmaceuticals in the aquatic environment in an urban river, with typical "down-the-drain" chemicals. Significantly high concentrations of specific antibiotics indicated non-negligible risks caused by the intensive use in the local aquatic environment in a metropolitan area, particularly ofloxacin in upstream Shahe Reservoir, middle stream and downstream Qing River, and Liangma River to the Ba River segment. Specific treatment measures for these pharmaceuticals and personal care products in STPs are required for such metropolitan areas. © 2015 SETAC.

Evaluation of evapotranspiration and deep percolation under mulched drip irrigation in an oasis of Tarim basin, China

NASA Astrophysics Data System (ADS)

Li, Xianwen; Jin, Menggui; Zhou, Nianqing; Huang, Jinou; Jiang, Simin; Telesphore, Habiyakare

2016-07-01

Mulched drip irrigation for cotton field is an effective measure for the utilization of saline water, and the regulation of soil water and salt. However, the reasonable methods for quantifying actual evapotranspiration (ET) and deep percolation of recharge to groundwater are still not very well understood, which restricts the accurate regulation of soil water and salt for cotton growth in oasis. In this paper, a set of experiments of mulched drip irrigation with brackish water were conducted in a typical arid region of Tarim basin in southern Xinjiang, China. The irrigation events were recorded, and ET and fluctuations of groundwater table were carefully measured for two consecutive irrigation periods of flowering and bolling stages. A group of upscaling conversion methods were used to quantify the ET, in which canopy structure was considered to estimate the transpiration from leaf scale to a unit of field scale. The groundwater table had a significant response to the irrigation events, thus the deep percolation was estimated using water-table fluctuation method (WTF). Results showed that during the two irrigation events of flowering and bolling stages, the total ET was 31.1 mm with the soil surface evaporation of only 0.4 mm. The total percolation of recharge to groundwater was 48.2 mm which contributed to the groundwater run-off of 22.1 mm. Transpiration of 30.7 mm accounted for 98.6% of the total ET of 31.1 mm and 34.3% of the irrigation water of 90.6 mm. Compared with transpiration, the deep percolation accounted for 53.2% of irrigation water, indicating a serious excessive irrigation that recharged to groundwater. Soil salt budget showed that the salt leached into groundwater was 1.56 times of the input from brackish irrigation water and fertilization during the two irrigation periods. Even for the irrigation practice with brackish water, the accumulated salt of soil profile could also be leached out under large amount of irrigation water (e.g. 90.6 mm for the

Coastline change and marine geo-hazards in the Yellow River Delta (China)

NASA Astrophysics Data System (ADS)

Zhou, L.; Liu, J.; Liu, X.

2003-04-01

COASTLINE CHANGE AND MARINE GEO-HAZARDS IN THE YELLOW RIVER DELTA (CHINA) Zhou Liangyong(1,2), Liu Jian(1,3), Liu Xiqing(1) (1)Qingdao Institute of Marine Geology,(2)Ocean University of China,(3)Research Centre for Coastal Geology, CGS qdzliangyong@cgs.gov.cn/Fax: +86-532-5720553 Satellite remote sensing, bathymetry and high-resolution seismic data have been used to examine the coastline change during the period from 1976 to 2001 and the offshore marine geo-hazards in the modern Yellow River Delta. Trends in the temporal sequence of the eight coastlines derived from Landsat images were used in the definition of erosional classes of the coastline. Four classes were distinguished, including rapid erosion (>100 m/yr), moderate erosion (20-100 m/yr), no detectable erosion (-1 - 20 m/yr), and accretion (-200--1 m/yr). We revealed the subtle variations in sea floor morphology and sediment geometries using high-resolution acoustic survey. Many kinds of geo-hazards were identified in the active subaqueous delta lobe and abandoned delta lobes, such as seabed erosions, gas-charged sediments, listric faults, synsedimentary rises, incised palaeo-valleys, infilled gullies, diapirs, active slope failures and sediment collapses. The resultant map of geo-envrionment and geo-hazards presents the coastline change and distribution of geo-hazards mentioned above in the Yellow River Delta. The gas-charged sediment distributes mainly in the abandoned delta lobes. The synsedimentary rise outside of the modern river mouth is a new evidence for the seabed mass-movement which modifies the progradational subaquaeous slopes of modern Yellow River Delta.

Where on Earth...? MISR Mystery Image Quiz #8:Yarlung Tsangpo River, China

NASA Image and Video Library

2002-05-15

The mighty river featured in this image is called the Yarlung Tsangpo in China, and is then known as the Dikrong during its passage through India state of Arunachal Pradesh. This image from NASA Terra satellite is MISR Mystery Image Quiz #8.

Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years

NASA Astrophysics Data System (ADS)

Tan, Liangcheng; Cai, Yanjun; Cheng, Hai; Edwards, Lawrence R.; Gao, Yongli; Xu, Hai; Zhang, Haiwei; An, Zhisheng

2018-01-01

The upper Hanjiang River region is the recharge area of the middle route of South-to-North Water Transfer Project. The region is under construction of the Hanjiang-Weihe River Water Transfer Project in China. Monsoon precipitation variations in this region are critical to water resource and security of China. In this study, high-resolution monsoon precipitation variations were reconstructed in the upper Hanjiang River region over the past 6650 years from δ18O and δ13C records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite δ18O record since the middle Holocene is consistent with other speleothem records from monsoonal China. This trend follows the gradually decreasing Northern Hemisphere summer insolation, which indicates that solar insolation may control the orbital-scale East Asian summer monsoon (EASM) variations. Despite the declined EASM intensity since the middle Holocene, local precipitation may not have decreased remarkably, as revealed by the δ13C records. A series of centennial- to decadal-scale cyclicity was observed, with quasi-millennium-, quasi-century-, 57-, 36- and 22-year cycles by removing the long-term trend of stalagmite δ18O record. Increased monsoon precipitation during periods of 4390-3800 a BP, 3590-2960 a BP, 2050-1670 a BP and 1110-790 a BP had caused four super-floods in the upper reach of Hanjiang River. Dramatically dry climate existed in this region during the 5.0 ka and 2.8 ka events, coinciding with notable droughts in other regions of monsoonal China. Remarkably intensified and southward Westerly jet, together with weakened summer monsoon, may delay the onset of rainy seasons, resulting in synchronous decreasing of monsoon precipitation in China during the two events. During the 4.2 ka event and the Little Ice Age, the upper Hanjiang River region was wet, which was similar to the climate conditions in central and southern China, but was the opposite of drought observed in northern China. We

Spatio-temporal variation analysis of hydrochemical characteristics in the Luanhe River Basin, China.

PubMed

Xie, Ying; Li, Xuyong; Wang, Huiliang; Li, Wenzan

2013-01-01

The analysis of river pollution and assessment of spatial and temporal variation in hydrochemistry are essential to river water pollution control in the context of rapid economic growth and growing pollution threats in China. In this study, we focused on hydrochemical characteristics of the Luanhe River Basin (China) and evaluation of 12 hydrochemical variables obtained from 32 monitoring stations during 2001-2010. In each study year, the streams were monitored in the three hydrological periods (April, August, and October) to observe differences in the impacts of agricultural activity and rainfall pattern. Multivariate statistical methods were applied to the data set, and the river water hydrochemical characteristics were assessed using the water quality identification index (WQIIM). The results showed that parameters had variable contribution to water quality status in different months except for ammonia nitrogen (NH4-N) and total nitrogen (TN), which were the most important parameters in contributing to water quality variations for all three periods. Results of WQIIM revealed that 18 sites were classified as 'meeting standard' while the other 14 sites were classified as 'not meeting standard', with most of the seriously polluted sites located in urban area, mainly due to discharge of wastewater from domestic and industrial sources. Sites with low pollution level were located primarily in smaller tributaries, whereas sites of medium and high pollution levels were in the main river channel and the larger tributaries. Our findings provide valuable information and guidance for water pollution control and water resource management in the Luanhe River Basin.

Simulating Water Resource Disputes of Transboundary River: A Case Study of the Zhanghe River Basin, China

NASA Astrophysics Data System (ADS)

Yuan, Liang; He, Weijun; Liao, Zaiyi; Mulugeta Degefu, Dagmawi; An, Min; Zhang, Zhaofang

2018-01-01

Water resource disputes within transboundary river basin has been hindering the sustainable use of water resources and efficient management of environment. The problem is characterized by a complex information feedback loop that involves socio-economic and environmental systems. This paper presents a system dynamics based model that can simulate the dynamics of water demand, water supply, water adequacy and water allocation instability within a river basin. It was used for a case study in the Zhanghe River basin of China. The base scenario has been investigated for the time period between 2000 and 2050. The result shows that the Chinese national government should change the water allocation scheme of downstream Zhanghe River established in 1989, more water need to be allocated to the downstream cities and the actual allocation should be adjusted to reflect the need associated with the socio-economic and environmental changes within the region, and system dynamics improves the understanding of concepts and system interactions by offering a comprehensive and integrated view of the physical, social, economic, environmental, and political systems.

Nutrient Loads Flowing into Coastal Waters from the Main Rivers of China (2006-2012).

PubMed

Tong, Yindong; Zhao, Yue; Zhen, Gengchong; Chi, Jie; Liu, Xianhua; Lu, Yiren; Wang, Xuejun; Yao, Ruihua; Chen, Junyue; Zhang, Wei

2015-11-19

Based on monthly monitoring data of unfiltered water, the nutrient discharges of the eight main rivers flowing into the coastal waters of China were calculated from 2006 to 2012. In 2012, the total load of NH3-N (calculated in nitrogen), total nitrogen (TN, calculated in nitrogen) and total phosphorus (TP, calculated in phosphorus) was 5.1 × 10(5), 3.1 × 10(6) and 2.8 × 10(5) tons, respectively, while in 2006, the nutrient load was 7.4 × 10(5), 2.2 × 10(6) and 1.6 × 10(5) tons, respectively. The nutrient loading from the eight major rivers into the coastal waters peaked in summer and autumn, probably due to the large water discharge in the wet season. The Yangtze River was the largest riverine nutrient source for the coastal waters, contributing 48% of the NH3-N discharges, 66% of the TN discharges and 84% of the TP discharges of the eight major rivers in 2012. The East China Sea received the majority of the nutrient discharges, i.e. 50% of NH3-N (2.7 × 10(5) tons), 70% of TN (2.2 × 10(6) tons) and 87% of TP (2.5 × 10(5) tons) in 2012. The riverine discharge of TN into the Yellow Sea and Bohai Sea was lower than that from the direct atmospheric deposition, while for the East China Sea, the riverine TN input was larger.

Estimation of nutrient discharge from the Yangtze River to the East China Sea and the identification of nutrient sources.

PubMed

Tong, Yindong; Bu, Xiaoge; Chen, Junyue; Zhou, Feng; Chen, Long; Liu, Maodian; Tan, Xin; Yu, Tao; Zhang, Wei; Mi, Zhaorong; Ma, Lekuan; Wang, Xuejun; Ni, Jing

2017-01-05

Based on a time-series dataset and the mass balance method, the contributions of various sources to the nutrient discharges from the Yangtze River to the East China Sea are identified. The results indicate that the nutrient concentrations vary considerably among different sections of the Yangtze River. Non-point sources are an important source of nutrients to the Yangtze River, contributing about 36% and 63% of the nitrogen and phosphorus discharged into the East China Sea, respectively. Nutrient inputs from non-point sources vary among the sections of the Yangtze River, and the contributions of non-point sources increase from upstream to downstream. Considering the rice growing patterns in the Yangtze River Basin, the synchrony of rice tillering and the wet seasons might be an important cause of the high nutrient discharge from the non-point sources. Based on our calculations, a reduction of 0.99Tg per year in total nitrogen discharges from the Yangtze River would be needed to limit the occurrences of harmful algal blooms in the East China Sea to 15 times per year. The extensive construction of sewage treatment plants in urban areas may have only a limited effect on reducing the occurrences of harmful algal blooms in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Magnetic Properties of the Rivers Feeding the South China Sea: a Critical Step for Understanding the Paleo-Marine Records.

NASA Astrophysics Data System (ADS)

Kissel, C.; Liu, Z.; Wandres, C.

2014-12-01

In order to use the magnetic properties of marine sediments as a tracer for past changes in the precipitation rate on land and in oceanic water masses transport and exchanges in the South China Sea, we identify and characterize the different sources of the detrital fraction among which the magnetic particles. This work is presently conducted in the framework of the Franco-Chinese LIA-MONOCL Thanks to the Westpac project, we had access to sediments collected in the deltas of the main rivers feeding the South China Sea from about 25°N to the equator. This is represented on the Asian continent by the Pearl river, the Red River, the Mekong river, by Malaysia, Sumatra and Borneo regions with minor rivers but also contributing to the South China Sea, and finally by Luzon and Taiwan. The geological formations contributing to the river sediment discharges are different from one catchment basin to another as well as the present climatic conditions. The magnetic analyses consist in the analysis of low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of 3-axes IRM, hysteresis parameters, and FORC diagrams. The obtained parameters all together allow us to define the nature of the magnetic grains and their grain size distribution when magnetite is dominant. Some degree of variability is observed at the river mouths, illustrating different geological sources at the local/regional scale. As an average, it appears that the Southern basin of the South China Sea is surrounded by regions richer in high coercivity magnetic minerals than the northern basin. This mineral is identified as hematite while magnetites (and sulfides) are more abundant in the north. These results are complementary to the clay mineral assemblages previously determined on the same samples. The first steps of a similar study conducted on marine core-tops well distributed in the South China Sea will also be illustrated.

Influence of changes in hydrodynamic conditions on cadmium transport in tidal river network of the Pearl River Delta, China.

PubMed

Dou, Ming; Zuo, Qiting; Zhang, Jinping; Li, Congying; Li, Guiqiu

2013-09-01

With rapid economic development, the Pearl River Delta (PRD) of China has experienced a series of serious heavy metal pollution events. Considering complex hydrodynamic and pollutants transport process, one-dimensional hydrodynamic model and heavy metal transport model were developed for tidal river network of the PRD. Then, several pollution emergency scenarios were designed by combining with the upper inflow, water quality and the lower tide level boundary conditions. Using this set of models, the temporal and spatial change process of cadmium (Cd) concentration was simulated. The influence of change in hydrodynamic conditions on Cd transport in tidal river network was assessed, and its transport laws were summarized. The result showed the following: Flow changes in the tidal river network were influenced remarkably by tidal backwater action, which further influenced the transport process of heavy metals; Cd concentrations in most sections while encountering high tide were far greater than those while encountering middle or low tides; and increased inflows from upper reaches could intensify water pollution in the West River (while encountering high tide) or the North River (while encountering middle or low tides).

Flux and fate of Yangtze River sediment delivered to the East China Sea

NASA Astrophysics Data System (ADS)

Liu, J. P.; Xu, K. H.; Li, A. C.; Milliman, J. D.; Velozzi, D. M.; Xiao, S. B.; Yang, Z. S.

2007-03-01

Numerous cores and dating show the Yangtze River has accumulated about 1.16 × 10 12 t sediment in its delta plain and proximal subaqueous delta during Holocene. High-resolution seismic profiling and coring in the southern East China Sea during 2003 and 2004 cruises has revealed an elongated (˜ 800 km) distal subaqueous mud wedge extending from the Yangtze River mouth southward off the Zhejiang and Fujian coasts into the Taiwan Strait. Overlying what appears to be a transgressive sand layer, this distal clinoform thins offshore, from ˜ 40 m thickness between the 20 and 30 m water depth to < 1-2 m between 60 and 90 m water depth, corresponding to an across shelf distance of less than 100 km. Total volume of this distal mud wedge is about 4.5 × 10 11 m 3, equivalent to ˜ 5.4 × 10 11 t of sediment. Most of the sediment in this mud wedge comes from the Yangtze River, with some input presumably coming from local smaller rivers. Thus, the total Yangtze-derived sediments accumulated in its deltaic system and East China Sea inner shelf have amounted to about 1.7 × 10 12 t. Preliminary analyses suggest this longshore and across-shelf transported clinoform mainly formed in the past 7000 yrs after postglacial sea level reached its mid-Holocene highstand, and after re-intensification of the Chinese longshore current system. Sedimentation accumulation apparently increased around 2000 yrs BP, reflecting the evolution of the Yangtze estuary and increased land erosion due to human activities, such as farming and deforestation. The southward-flowing China Coastal Current, the northward-flowing Taiwan Warm Current, and the Kuroshio Current appear to have played critical roles in transporting and trapping most of Yangtze-derived materials in the inner shelf, and hence preventing the sediment escape into the deep ocean.

Contamination characteristics of organochlorine pesticides in multimatrix sampling of the Hanjiang River Basin, southeast China.

PubMed

Liu, Jia; Qi, Shihua; Yao, Jun; Yang, Dan; Xing, Xinli; Liu, Hongxia; Qu, Chengkai

2016-11-01

Hanjiang River, the second largest river in Guangdong Province, Southern China, is the primary source of drinking water for the cities of Chaozhou and Shantou. Our previous studies indicated that soils from an upstream catchment area of the Hanjiang River are moderately contaminated with organochlorine pesticides (OCPs), which can easily enter the river system via soil runoff. Therefore, OCPs, especially downstream drinking water sources, may pose harmful health and environmental risks. On the basis of this hypothesis, we measured the OCP concentrations in dissolved phase (DP), suspended particle matter (SPM), and surface sediment (SS) samples collected along the Hanjiang River Basin in Fujian and Guangdong provinces. OCP residue levels were quantified through electron capture detector gas chromatography to identify the OCP sources and deposits. The concentration ranges of OCPs in DP, SPM, and SS, respectively, were 2.11-12.04 (ng/L), 6.60-64.77 (ng/g), and 0.60-4.71 (ng/g) for hexachlorocyclohexanes (HCHs), and 2.49-4.77 (ng/L), 6.75-80.19 (ng/g), and 0.89-252.27 (ng/g) for dichloro-diphenyl-trichloroethanes (DDTs). Results revealed that DDTs represent an ecotoxicological risk to the Hanjiang River Basin, as indicated by international sediment guidelines. This study serves as a basis for the future management of OCP concentrations in the Hanjiang River Basin, and exemplifies a pattern of OCP movement (like OCP partition among multimedia) from upstream to downstream. This pattern may be observed in similar rivers in China. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of mantle dynamics in rebuilding the Tianshan Orogenic Belt in NW China: A seismic tomographic investigation

NASA Astrophysics Data System (ADS)

He, Chuansong; Santosh, M.

2018-05-01

The Tianshan orogenic belt, Junggar terrane and Altai terrane are located at the southwestern part of the Central Asian Orogenic Belt (CAOB). Here, we investigate the velocity structure beneath the Xinjiang region in NW China, which includes the Tarim terrane, Tianshan orogenic belt, Junggar terrane and Altai terrane with a view to evaluate the mantle dynamics based on teleseismic data recorded by 103 seismic stations. Our tomographic results show both high and low velocity perturbations beneath the Tianshan orogenic belt. We suggest that the high velocity perturbations beneath this orogenic belt might represent the northward subducted lithosphere of the Tarim Basin and the southward subducted lithosphere of the Junggar Basin. The low velocity structure beneath the Tianshan orogenic belt might represent asthenosphere upwelling that triggered the extensive magmatism which contributed to rebuilding of the Tianshan orogenic belt.

Investigating the evolutionary history of irrigated agricultural technology in the Heihe River Basin, China

NASA Astrophysics Data System (ADS)

Wu, S.; Wei, Y.; Zhao, Y.; Zheng, H.

2017-12-01

Human's innovative abilities do not only enable rapid expansion of civilization, but also lead to enormous modifications on the natural environment. Technology, while a key factor embedded in socioeconomic developments, its impacts have been rarely appropriately considered in river basin management. This research aims to examine the evolutionary history of irrigated agricultural technology in the Heihe River Basin, China, and how its characteristics interacted with the river basin environment. It adopts a content analysis approach to collect and summarize quantitative technological information in the Heihe River Basin across a time span of more than 2000 years from the Han Dynasty (206 BC) to 2015. Two Chinese academic research databases: Wan Fang Data and China National Knowledge Infrastructure (CNKI) were chosen as data sources. The results show that irrigated agricultural technologies in Heihe River Basin have shifted from focusing on developing new farming tools and cultivation methods to adapting modernized, water-saving irrigation methods and water diversion infrastructures. In additions, the center of irrigated agricultural technology in the Heihe river basin has moved from downstream to middle stream since the Ming Dynasty (1368AD) as a result of degraded natural environment. The developing trend of technology in the Heihe River Basin thus coincides with the change of societal focus from agricultural production efficiency to the human-water balance and environmental remediation. This research demonstrates that irrigated agricultural technologies had a twisted evolutionary history in the Heihe River Basin, influenced by a diverse range of environmental and socioeconomic factors. It provides insights into the fact that technology exhibits a co-evolutionary characteristic with the social development history in the region, pointing towards the urgent need to maintain the balance between human and environment.

Hydrological controls on chemical weathering in the typical carbonated river basin, SW China

NASA Astrophysics Data System (ADS)

LI, S. L.; Jin, L.; Zhong, J., Sr.

2016-12-01

The dynamics of dissolved load in the riverine system could provide an insight in understanding the surface processes, such as chemical weathering and carbon cycle. The Xijiang River is a typical carbonated river basin, located at southwestern China. The Xijiang River catchment is controlled by a humid subtropical climate. In spite of being impacted by monsoonal climate and with significant variations of discharge, the temporal variations of compositions of main ions and chemical weathering of Xijiang River are rarely documented. In this study, a systematic investigation on the seasonal and episodic water geochemistry (major ions and d13CDIC) of the major branch and outlet of Xijiang River were carried out with the purpose of 1) characterizing temporal variations of aqueous geochemistry and its controlling factors, 2) exploring the impact of hydrological controls on chemical weathering of the Xijiang River Basin. The results show that the concentrations of Cl, Na, Ca, Mg, and HCO3 are generally decreased during monsoon season, which should be mainly caused by dilution. However, the dilution effect does not strictly follow the theoretical dilution curve. Moreover, d13CDIC in the high-flow period has more negative values than in low-flow period. More negative δ13CDIC values in the river during the wet season reflected the influx of rain water with biological CO2 during the rain event. This study suggested that hydrochemistry and d13CDIC had a large variation responding to rainstorm events. The calculated results show that the weathering rates of silicate and carbonate as well as that of related CO2 consumption have a positive relation with water discharge, highlighting the hydrological controls on chemical weathering and CO2 consumption rates. The results indicated carbonated weathering rate responding to hydrological condition sensitivity in the typical carbonate river basin. This work was supported by The China National Science Fund for Outstanding Young Scholars

Occurrence of PPCPs in Pearl River Estuary and South China Sea

NASA Astrophysics Data System (ADS)

Fisch, Kathrin; Waniek, Joanna J.; Schulz-Bull, Detlef E.

2017-04-01

The development of a coastal megacity has put the South China Sea under human induced stress. Pharmaceuticals and personal care products (PPCPs) are ubiquitous contaminants and can be used as anthropogenic indicators for pollution of the marine environment. They enter the marine environment indirectly via waste water or directly due to recreational activities. PPCPs make up a group of different pharmaceuticals such as antibiotic, anti-inflammatories etc. and personal care products such as UV-filters. A mayor concern is the unknown fate and the effect these pollutants on the marine environment and especially its organisms. In some studies it was proven that some of these PPCPs have an endocrine disrupting and/or a subtle chronic effect on aquatic organisms. They are of concern for the health of the marine environment and may have an effect on human health. With our study we could determine the occurrence of PPCPs in the Pearl River estuary and the South China Sea. Salicylic acid (metabolite of acetylsalicylic acid) and octocrylene (UV-filter) were found in the open Sea in low ng/L concentration. Octocrylene is used in sunscreen and as a light stabilizer in paints and polymer-based products. It is of environmental concern because of its potential to be bioaccumulative. In addition to our findings in the open South China Sea, could we detect PPCPs, especially antibiotics, in higher ng/L-concentrations in the Pearl River Estuary.

Nutrient Loads Flowing into Coastal Waters from the Main Rivers of China (2006–2012)

PubMed Central

Tong, Yindong; Zhao, Yue; Zhen, Gengchong; Chi, Jie; Liu, Xianhua; Lu, Yiren; Wang, Xuejun; Yao, Ruihua; Chen, Junyue; Zhang, Wei

2015-01-01

Based on monthly monitoring data of unfiltered water, the nutrient discharges of the eight main rivers flowing into the coastal waters of China were calculated from 2006 to 2012. In 2012, the total load of NH3-N (calculated in nitrogen), total nitrogen (TN, calculated in nitrogen) and total phosphorus (TP, calculated in phosphorus) was 5.1 × 105, 3.1 × 106 and 2.8 × 105 tons, respectively, while in 2006, the nutrient load was 7.4 × 105, 2.2 × 106 and 1.6 × 105 tons, respectively. The nutrient loading from the eight major rivers into the coastal waters peaked in summer and autumn, probably due to the large water discharge in the wet season. The Yangtze River was the largest riverine nutrient source for the coastal waters, contributing 48% of the NH3-N discharges, 66% of the TN discharges and 84% of the TP discharges of the eight major rivers in 2012. The East China Sea received the majority of the nutrient discharges, i.e. 50% of NH3-N (2.7 × 105 tons), 70% of TN (2.2 × 106 tons) and 87% of TP (2.5 × 105 tons) in 2012. The riverine discharge of TN into the Yellow Sea and Bohai Sea was lower than that from the direct atmospheric deposition, while for the East China Sea, the riverine TN input was larger. PMID:26582206

Magnetic properties of the rivers feeding the South China Sea: a critical step for understanding the paleo-marine records.

NASA Astrophysics Data System (ADS)

Kissel, Catherine; Liu, Zhifei; Wandres, Camille; Liu, Qingsong

2014-05-01

In order to use the magnetic properties of marine sediments as a tracer for past changes in the precipitation rate and in oceanic water masses transport and exchanges, it is critical to identify and to characterize the different sources of the detrital fraction among which the magnetic particles. This is of peculiar importance in marginal seas such as the South China Sea extending from about 25°N to the equator. Thanks to the Westpac project, we had access to a number of sediments collected in the deltas of the main rivers feeding the South China Sea. This is represented on the Asian continent by the Pearl river, the Red River, the Mekong river, by Malaysia, Sumatra and Borneo regions with minor rivers but also contributing to the South China Sea, and finally by Luzon and Taiwan. The geological formations contributing to the river sediment discharges are different from one catchment basin to another as well as the present climatic conditions. The magnetic analyses conducted on the samples are the low-field magnetic susceptibility, the ARM acquisition and decay, the IRM acquisition and decay, the back-field acquisition, the thermal demagnetization of 3-axes IRM, the hysteresis parameters, the FORC diagrams. The obtained parameters all together allow us to define the nature of the magnetic grains and their grain size distribution when magnetite is dominant. Some degree of variability is observed at the river mouths, illustrating different geological sources at the local/regional scale. As an average, it appears that the Southern basin of the South China Sea is surrounded by regions richer in high coercivity magnetic minerals than the northern basin. This mineral is identified as hematite while magnetite is more abundant in the north. These results are complementary to the clay mineral assemblages previously determined on the same samples. We'll give some example of how this knowledge allows us to interpret the paleo-marine records from the South China Sea in terms

Temporal variation and regional transfer of heavy metals in the Pearl (Zhujiang) River, China.

PubMed

Zhen, Gengchong; Li, Ying; Tong, Yindong; Yang, Lei; Zhu, Yan; Zhang, Wei

2016-05-01

Heavy metals are highly persistent in water and have a particular significance in ecotoxicology. Heavy metals loading from the Pearl River are likely to cause significant impacts on the environment in the South China Sea and the West Pacific. In this study, using monthly monitoring data from a water quality monitoring campaign during 2006-2012, the temporal variation and spatial transfer of six heavy metals (lead (Pb), copper (Cu), cadmium (Cd), zinc (Zn), arsenic (As), and mercury (Hg)) in the Pearl River were analyzed, and the heavy metal fluxes into the sea were calculated. During this period, the annual heavy metal loads discharged from the Pearl River into the South China Sea were 5.8 (Hg), 471.7 (Pb), 1524.6 (Cu), 3819.6 (Zn), 43.9 (Cd), and 621.9 (As) tons, respectively. The metal fluxes showed a seasonal variation with the maximum fluxes occurring from June to July. There is a close association between metal fluxes and runoff. The analysis of the heavy metal transfer from the upstream to the downstream revealed that the transfer from the upstream accounted for a major portion of the heavy metals in the Pearl River Delta. Therefore, earlier industry relocation efforts in the Pearl River watershed may have limited effect on the water quality improvement in surrounding areas. It is suggested that watershed-based pollution control measures focusing on wastewater discharge in both upstream and downstream areas should be developed and implemented in the future.

[Pollution and Potential Ecology Risk Evaluation of Heavy Metals in River Water, Top Sediments on Bed and Soils Along Banks of Bortala River, Northwest China].

PubMed

Zhang, Zhao-yong; Abuduwaili, Jilili; Jiang, Feng-qing

2015-07-01

This paper focuses on the sources, pollution status and potential ecology risks of heavy metals (Cr, Cu, Hg, As, Cd, Pb, and Zn) in the surface water, top sediment of river bed and soil along banks of Bortala River, which locates in the oasis region of Xinjiang, northwest China. Results showed that: (1) As a whole, contents of 7 tested heavy metals of Bortala River were low, while the maximum values of Hg, Cd, Pb, and Cr in the river water were significantly higher than those of Secondary Category of the Surface Water Quality Standards of People's Republic of China (GB 3838-2002) and Drinking Water Guideline from WHO. Analysis showed that the heavy metals contents of top sediment on river bed and soils along river banks were significantly higher than those of the river water. (Correlation analysis and enrichment factor (EF) calculation showed that in the river water, top sediment on river bed and soils along river banks, Hg, Cd, Pb, and Cr mainly originated from industrial emissions, urban and rural anthropogenic activities, transportation and agricultural production activities; While Cu, Zn, and As mainly originated from natural geological background and soil parent materials. (3) Pollution assessment showed that in three matrices, the single factor pollution index(Pi) and the integrated pollution index (Pz) of 7 heavy metals were all lower than 1, and they all belonged to safe and clean levels. (4) Potential ecology risk evaluation showed that as a whole the single factor potential ecological risk (Eir) and the integrated potential ecology risks (RI) of 7 heavy metals were relatively low, and would not cause threats to the health of water and soil environment of river basin, while the potential ecology risks of Cd, Hg, Pb, and Cr were significantly higher than those of other heavy metals.

Occurrence, distribution and sources of organochlorine pesticides (OCPs) in surface sediments from the Lijiang River, a typical karst river of southwestern China.

PubMed

Zhang, Dan; Wang, Yinghui; Yu, Kefu; Li, Pingyang; Zhang, Ruijie; Xu, Yiyin

2014-11-01

The Lijiang River is a typical karst river of southwestern China. Karst-aquifer systems are more vulnerable to contamination compared to other types of aquifers. The occurrence and distribution of organochlorine pesticides (OCPs) in surface sediments from the Lijiang River were investigated to evaluate their potential ecological risks. The total concentrations of them in sediments ranged from 0.80 to 18.73 ng/g dry weight (dw) (mean 6.83 ng/g dw). The residue levels of OCPs varied in the order of HCB > HCHs > DDTs. Compositional analyses of OCPs showed that HCHs and DDTs were mainly from historical usage. The ecological risk assessment suggested that HCHs and DDTs in Lijiang River sediments may cause adverse ecological risks, particularly at sites near agricultural areas.

Sources of excess urban carbonaceous aerosol in the Pearl River delta region, China

EPA Science Inventory

Carbonaceous aerosol is one of the important constituents of fine particulate matter (PM2.5) in Southern China, including the Pearl River Delta (PRD) region and Hong Kong (HK). During the study period (October and December of 2002, and March and June of 2003), the monthly average...

Modifications in the land surface model ORCHIDEE and application in the Tarim basin

NASA Astrophysics Data System (ADS)

Zhou, Xudong; Polcher, Jan; Yang, Tao; Nguyen Quang, Trung; Hirabayashi, Yukiko

2017-04-01

Land surface modeling in regions mixing high mountains and arid deserts remains a great challenge due to the inadequate representations of physical processes in atmospheric forcings , runoff generation, evaporation and river routing. A few key improvements were analyzed within ORCHIDEE (Organising Carbon and Hydrology in Dynamic Ecosystems) to better understand these limitations as well as quantify their influence on the water cycle over Tarim basin (TRB). The TRB is a representative endorheic basin in center Asia, with glacier and snow melting, limited precipitation but strong evaporation, high spatial heterogeneity and intensive human interference, thus challenging any land surface model. National observations on daily precipitation from China Meteorological Administration (CMA) were used to correct precipitation inputs on the basis of WATCH forcing datasets. The independent glacier melting simulation by HYOGA2 was added to the forcing to overcome the lack of glacier module in ORCHIDEE. Improvements in the snow scheme provided more accurate simulations of the soil temperature which restrict the infiltration process when the soil is frozen. In addition, a novel routing scheme with finer spatial resolution from 50km to 1km was developed based on HydroSHED map. It improves the descriptions of catchments boundaries, the flow direction and the water residence time within sub-basins that make significant difference especially for the mountainous area and flat plains. Model results with these modifications were compared through various atmospheric and hydrological variables (i.e. evaporation, soil moisture, runoff and discharge). In conclusion, the correction by the precipitation observations and involvement of glacier melting simulations increase the water input to the basin by 37.2% and 8.4% respectively, which in turn increases evaporation, soil moisture and runoff to different extents. The new snow and soil freezing scheme advance in time the spring high-water in

Agricultural land use doubled sediment yield of western China's rivers

NASA Astrophysics Data System (ADS)

Schmidt, A. H.; Bierman, P. R.; Sosa-Gonzalez, V.; Neilson, T. B.; Rood, D. H.; Martin, J.; Hill, M.

2017-12-01

Land use changes, such as deforestation and agriculture, increase soil erosion rates on the scale of hillslopes and small drainage basins; however, the effects of these changes on the sediment load in larger rivers is poorly quantified, with a few studies scattered globally, and only 10 data points in the world's most populous nation, China. At 20 different sites in western China, we compare contemporary (1945-1987) fluvial sediment yield data collected daily over 4 to 26 years (median = 19 years) to long-term measures of erosion (sediment generation) based on new isotopic measurements of in situ 10Be in river sediments. We find that median sediment transport at these sites exceeds background sediment generation rates by a factor of two (from 0.13 to 5.79 times, median 1.85 times) and that contemporary sediment yield is statistically significantly different from long-term sediment yield (p < 0.05). Agricultural land use is directly and significantly proportional to the ratio of contemporary sediment yield to long term sediment generation rates (Spearman correlation coefficient rho = 0.52, p < 0.05). We support these findings by calculating erosion indices (following Brown et al., 1988), which compare the delivery of meteoric 10Be to each watershed with the export of meteoric 10Be bound to riverine sediment. Erosion indices are also directly and significantly proportional to agricultural land use (rho = 0.58, p < 0.05). We measured unsupported 210Pb and 137Cs in 130 detrital samples from throughout the region. We find that only 4 samples (those from high elevation, low relief watersheds) have detectable 137Cs and 31 samples have detectable unsupported 210Pb. The lack of 137Cs in most samples suggests high rates of erosion in the 1950s-1960s when 137Cs would have been delivered to the landscape. Detectable 210Pb in 25% of the watersheds suggests that in some areas erosion rates have slowed since that time allowing 210Pb to accumulate to measurable levels. Together

An integrated multiscale river basin observing system in the Heihe River Basin, northwest China

NASA Astrophysics Data System (ADS)

Li, X.; Liu, S.; Xiao, Q.; Ma, M.; Jin, R.; Che, T.

2015-12-01

Using the watershed as the unit to establish an integrated watershed observing system has been an important trend in integrated eco-hydrologic studies in the past ten years. Thus far, a relatively comprehensive watershed observing system has been established in the Heihe River Basin, northwest China. In addition, two comprehensive remote sensing hydrology experiments have been conducted sequentially in the Heihe River Basin, including the Watershed Allied Telemetry Experimental Research (WATER) (2007-2010) and the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) (2012-2015). Among these two experiments, an important result of WATER has been the generation of some multi-scale, high-quality comprehensive datasets, which have greatly supported the development, improvement and validation of a series of ecological, hydrological and quantitative remote-sensing models. The goal of a breakthrough for solving the "data bottleneck" problem has been achieved. HiWATER was initiated in 2012. This project has established a world-class hydrological and meteorological observation network, a flux measurement matrix and an eco-hydrological wireless sensor network. A set of super high-resolution airborne remote-sensing data has also been obtained. In addition, there has been important progress with regard to the scaling research. Furthermore, the automatic acquisition, transmission, quality control and remote control of the observational data has been realized through the use of wireless sensor network technology. The observation and information systems have been highly integrated, which will provide a solid foundation for establishing a research platform that integrates observation, data management, model simulation, scenario analysis and decision-making support to foster 21st-century watershed science in China.

Sources and Dynamics of Inorganic Carbon within the Upper Reaches of the Xi River Basin, Southwest China

PubMed Central

Zou, Junyu

2016-01-01

The carbon isotopic composition (δ13C) of dissolved and particulate inorganic carbon (DIC; PIC) was used to compare and analyze the origin, dynamics and evolution of inorganic carbon in two headwater tributaries of the Xi River, Southwest China. Carbonate dissolution and soil CO2 were regarded as the primary sources of DIC on the basis of δ13CDIC values which varied along the Nanpan and Beipan Rivers, from −13.9‰ to 8.1‰. Spatial trends in DIC differed between the two rivers (i.e., the tributaries), in part because factors controlling pCO2, which strongly affected carbonate dissolution, differed between the two river basins. Transport of soil CO2 and organic carbon through hydrologic conduits predominately controlled the levels of pCO2 in the Nanpan River. However, pCO2 along the upper reaches of the Nanpan River also was controlled by the extent of urbanization and industrialization relative to agriculture. DIC concentrations in the highly urbanized upper reaches of the Nanpan River were typical higher than in other carbonate-dominated areas of the upper Xi River. Within the Beipan River, the oxidation of organic carbon is the primary process that maintains pCO2 levels. The pCO2 within the Beipan River was more affected by sulfuric acid from coal industries, inputs from a scenic spot, and groundwater than along the Nanpan River. With regards to PIC, the contents and δ13C values in the Nanpan River were generally lower than those in the Beipan River, indicating that chemical and physical weathering contributes more marine carbonate detritus to the PIC along the Beipan River. The CO2 evasion flux from the Nanpan River was higher than that in the Beipan River, and generally higher than along the middle and lower reaches of the Xi River, demonstrating that the Nanpan River is an important net source of atmospheric CO2 in Southwest China. PMID:27513939

Landsat View: Pearl River Delta, China

NASA Image and Video Library

2017-12-08

In 1979, China established two special economic zones around the Pearl River Delta, north of Hong Kong. This image, taken by Landsat 3 on October 19, 1973, shows that the region was rural when the zone was established. Plant-covered land, which is red in this false-color image, dominates the scene. Square grids are agriculture. By January 10, 2003, when Landsat 7 took this image, the Pearl River Delta was a densely populated urban corridor with several large cities. The urban areas are gray in this image. The region is a major manufacturing center with an economy the size of Taiwan’s. As of 2010, the Pearl River Economic Zone had a population of 36 million people. ---- NASA and the U.S. Department of the Interior through the U.S. Geological Survey (USGS) jointly manage Landsat, and the USGS preserves a 40-year archive of Landsat images that is freely available over the Internet. The next Landsat satellite, now known as the Landsat Data Continuity Mission (LDCM) and later to be called Landsat 8, is scheduled for launch in 2013. In honor of Landsat’s 40th anniversary in July 2012, the USGS released the LandsatLook viewer – a quick, simple way to go forward and backward in time, pulling images of anywhere in the world out of the Landsat archive. NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Flooding Mitigation of seawalls and river embankments to storm surges in the coastal areas of Guangdong Province, China

NASA Astrophysics Data System (ADS)

Wang, Xianwei; Wang, Xina

2017-04-01

The coastal areas of Guangdong Province, China are susceptible to the destructions of tropical cyclones and storm surges. The projected global warming, coastal subsidence and sea level rise together will bring about greater flooding risk to these areas. The seawall and river embankment have played a significant role in mitigating and preventing the coastal low-land areas from the impairment of storm surges flooding and wave runup. However, few risk assessment studies in this region consider the existence of seawall and river embankment and often overestimate the risk and potential economic loss and population affected due to storm surge flooding. This study utilizes a hydraulic model to simulate the overtop flooding and compare those without seawall and river embankment using several specific tropic storm events and extreme events of tropic storm surges in different return periods of 2, 10, 20, 50, 100, 200 and 500 years. Most seawalls are 4 or 5 meters plus another meter of wave levee above the local mean sea level. The river embankments are usually 4 or 5 meter higher than the local mean sea level as well and decrease from the outer estuary to the inner riverine. The modeling results considering seawall and river embankments and from real storm surges are in agreement with on-site survey and observations, while those without infusing seawall and river embankments overestimate the inundation condition and economic loss. Modeling results demonstrate that seawall and river embankment greatly reduce the flooding risk and prevent the low-land area from inundation for most tropic storm events, e.g., for extreme events less than 20 to 50 years, in the coastal areas of Guangdong Province, China. However, the seawall and river embankment may also cause catastrophic disasters once there is an engineering failure of seawalls and river embankment, especially once encountering with an extreme typhoon event, e.g., the 1969 super typhoon Viola in Shantou China and the 2005

Introduction to special section: China shale gas and shale oil plays

USGS Publications Warehouse

Jiang, Shu; Zeng, Hongliu; Zhang, Jinchuan; Fishman, Neil; Bai, Baojun; Xiao, Xianming; Zhang, Tongwei; Ellis, Geoffrey S.; Li, Xinjing; Richards-McClung, Bryony; Cai, Dongsheng; Ma, Yongsheng

2015-01-01

Even though China shale gas and shale oil exploration is still in an early stage, limited data are already available. We are pleased to have selected eight high-quality papers from fifteen submitted manuscripts for this timely section on the topic of China shale gas and shale oil plays. These selected papers discuss various subject areas including regional geology, resource potentials, integrated and multidisciplinary characterization of China shale reservoirs (geology, geophysics, geochemistry, and petrophysics) China shale property measurement using new techniques, case studies for marine, lacustrine, and transitional shale deposits in China, and hydraulic fracturing. One paper summarizes the regional geology and different tectonic and depositional settings of the major prospective shale oil and gas plays in China. Four papers concentrate on the geology, geochemistry, reservoir characterization, lithologic heterogeneity, and sweet spot identification in the Silurian Longmaxi marine shale in the Sichuan Basin in southwest China, which is currently the primary focus of shale gas exploration in China. One paper discusses the Ordovician Salgan Shale in the Tarim Basin in northwest China, and two papers focus on the reservoir characterization and hydraulic fracturing of Triassic lacustrine shale in the Ordos Basin in northern China. Each paper discusses a specific area.

Permian charnockites in the Pobeda area: Implications for Tarim mantle plume activity and HT metamorphism in the South Tien Shan range

NASA Astrophysics Data System (ADS)

Loury, Chloé; Rolland, Yann; Lanari, Pierre; Guillot, Stéphane; Bosch, Delphine; Ganino, Clément; Jourdon, Anthony; Petit, Carole; Gallet, Sylvain; Monié, Patrick; Riel, Nicolas

2018-04-01

The Permian history of the Central Asian Orogenic belt is marked by large-scale strike-slip faults that reactivate former Paleozoic structures, delineated by widespread alkaline magmatism. The genetic link between the syn-kinematic granitoids emplaced in the Tien Shan range and magmas emplaced within the Tarim Large Igneous Province, and the interaction between this plume and transcurrent tectonics, are still unsolved issues. We investigated the Pobeda massif, in the eastern Kyrgyz Tien Shan, located at the boundary between the Tien Shan range and the Tarim Craton, which exhibits a high-temperature unit. In this unit, Permian magmatism resulted in the emplacement of alkaline charnockites at mid-crustal levels. The primary mineralogical assemblage is nominally anhydrous and made of ortho- and clino-pyroxenes, fayalite, K-feldspar, plagioclase and quartz. These charnockites are associated with partially-molten paragneisses and marbles. Thermobarometry on these rocks indicates that the charnockites emplaced following the intrusion of a melt at a temperature > 1000 °C and pressure of around 6 kbar, corresponding to depth of 20 km. The resulting thermal anomaly triggered the partial melting of paragneisses. Bulk geochemistry including Sr, Nd, Pb and Hf isotopes suggests that charnockites fit into the Tarim Large Igneous Province magmatic series, with minor crustal assimilation. U-Pb ages on zircons of charnockites and surrounding paragneisses indicate that charnockites intruded and triggered partial melting of the gneisses at c. 287, 275 and 265 Ma. 40Ar/39Ar dating on amphibole gives a similar age as the U-Pb age at 276.2 ± 2.0 Ma. 40Ar/39Ar dating on biotite from the Charnockite unit marbles gives ages at ca. 256-265 Ma, which shows that exhumation onset directly follows the HT history, and is tentatively correlated to top-to-the-North thrusting of the Charnockite unit in a transpressive context. Additional 40Ar/39Ar dating on syn-kinematic white micas from an

Simulation of 1998-Big Flood in Changjiang River Catchment, China

NASA Astrophysics Data System (ADS)

Nakayama, T.; Watanabe, M.

2006-05-01

Almost every year, China is affected by severe flooding, which causes considerable economic loss and serious damage to towns and farms. Big floods are mainly concentrated in the middle and lower reaches of the "seven big rivers", which include the Changjiang (Yangtze) River, the Yellow (Huanghe) River, and the Huaihe River. The Changjiang River is the fourth largest water resource to the oceans after the Amazon, Zaire, and Orinoco Rivers. In addition to abnormal weather, artificial effects were considered as main causes of the big flood disaster in the Changjiang River catchment by the previous researches; (i) extreme deforestation and soil erosion in the upper reaches, (ii) shrinking of lake water volumes and their reduced connection with the Changjiang River due to reclamation of lakes that retarded water in the middle reaches, and (iii) restriction of channel capacity following levee construction. Because there is an urgent need to quantify these relations on the spatial scale of the whole catchment in order to prevent flood damage as small as possible, it is very important to evaluate the complicated phenomena of water/heat dynamics in the Changjiang River catchment by using process-based models. The present research focuses on simulating the water/heat dynamics for 1998 big-flood with 60-year recurrent period in the Changjiang River catchment. We compared the flood period of 1998 with the normal period of 1987-1988. We expanded the NIES Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama and Watanabe, 2004; Nakayama et al., 2006) for the application to broader catchments in order to evaluate large- scale flooding in the Changjiang River (NICE-FLD). We simulated the water/heat dynamics in the entire catchment (3,000 km wide by 1,000 km long) with a resolution of 10 km mesh by using the NICE-FLD. The model reproduced excellently the river discharge, soil moisture, evapotranspiration, groundwater level, et al. Furthermore, we evaluated the role of

Effective Elastic Thickness of the Lithosphere in Continental China from Heat Flow: Implications for the Lithospheric Rheology

NASA Astrophysics Data System (ADS)

Liu, S.; Wang, L.

2006-12-01

The effective elastic thickness (Te) of lithosphere is one parameter describing the responses of the lithosphere to long term forces, and is still controversial in estimation by different methods. Here we present the effective elastic thickness of the lithosphere in continental China from heat flow data by the method proposed by Burov et al, J.G.R., 1995,100(B3):3905-3927. Our results show that Te varies much in different sub-areas in continental China due to different geological evolution and associated thermal regimes. Te is much greater than the crustal thickness in the area where the heat flow is really low and the lithosphere is really thick, indicating much more contribution from the lithospheric mantle and the dominative control of the mantle with olivine on the rheology of the lithosphere, and the major basins (Tarim, Junggar, Ordos and Sichuan basins) in central-western China share this characteristic. For instance, the Te of the Tarim basin is 66km with crustal thickness of 45km. Te is less than the crustal thickness in the region where the heat flow is relatively high, and approximates to the crustal brittle-ductile transition depth, suggesting more contribution from the crust and the dominative control of the felsic crust on the rheology of the lithosphere, and this phenomenon is obvious in the SE coastal China, eastern North China and the orogenic belts. Compared the estimated Te with the seismogenic layer thickness (Ts) available in China, it is also found that the Te is much greater than Ts in the major basins with low heat flow, and is similar to Ts in the active zones with high heat flow, which is inconsistent with that Te is usually smaller than Ts proposed by Maggi et al., Geology,2000,28(6):495-498. Generally, two end elements rheological modes for continental lithosphere of the strong crust-weak mantle and the weak crust-strong mantle are all available in continental China considering different thermal regime, composition and geological

Anomalies of natural gas compositions and carbon isotope ratios caused by gas diffusion - A case from the Donghe Sandstone reservoir in the Hadexun Oilfield, Tarim Basin, northwest China

NASA Astrophysics Data System (ADS)

Wang, Yangyang; Chen, Jianfa; Pang, Xiongqi; Zhang, Baoshou; Wang, Yifan; He, Liwen; Chen, Zeya; Zhang, Guoqiang

2018-05-01

Natural gases in the Carboniferous Donghe Sandstone reservoir within the Block HD4 of the Hadexun Oilfield, Tarim Basin are characterized by abnormally low total hydrocarbon gas contents (<65%), low methane contents (<10%) and low dryness coefficients (<0.5), and a reversal of the normal trend of carbon isotope ratios, showing δ13C methane (C1) > δ13C ethane (C2) < δ13C propane (C3) < δ13C butane (C4). Specifically, methane is enriched in 13C with the variations in δ13C1 values between gases from Block HD4 and gases from its neighboring blocks reaching 10‰. This type of abnormal gas has never been reported previously in the Tarim Basin and such large variations in δ13C have rarely been observed in other basins globally. Based on a comprehensive analysis of gas geochemical data and the geological setting of the Carboniferous reservoirs in the Hadexun Oilfield, we reveal that the anomalies of the gas compositions and carbon isotope ratios in the Donghe Sandstone reservoir are caused by gas diffusion through the poorly-sealed caprock rather than by pathways such as gas mixing, microorganism degradation, different kerogen types or thermal maturity degrees of source rocks. The documentation of an in-reservoir gas diffusion during the post entrapment process as a major cause for gas geochemical anomalies may offer important insight into exploring natural gas resources in deeply buried sedimentary basins.

An Integrated 3S and Historical Materials Analysis of the Keriya Paleoriver, NW China

NASA Astrophysics Data System (ADS)

Luo, Lei; Wang, Xinyuan; Cai, Heng

2014-03-01

Combining analysis of 3S (RS, GIS and GPS) and historical materials (historical records, ancient map and academic and literary writings) allows mapping of the Keriya Paleoriver of Southern Xinjiang, NW China. Keriya Paleoriver, one of the ancient Four Green Corridors which passes through the Taklimakan Desert from south to north in the Tarim Basin, recorded changes of the climate-environment in the ancient Silk Road of the region. According to the archaeological data, historical materials and paleoclimates information, its eco-environment and climate have had great changes since the 1.09Ma B.P., especially during the last 2,000 years, which has led to many famous ancient cities to be abandoned and the route of the ancient Silk Road to be moved southward. Using RS (optical and radar imagery), GIS (mapping and spatial analysis) and GPS (study area investigation), we mapped a major paleodrainage system of Keriya River, which have linked the Kunlun Mountains to the Tienshan Mountains through the Taklimakan Desert, possibly as far back as the early Pleistocene. This study illustrates the capability of the 3S and historical materials, in mapping the Keriya Paleoriver drainage networks and archaeological study on the ancient Silk Road.

The concentration and chemical speciation of arsenic in the Nanpan River, the upstream of the Pearl River, China.

PubMed

Yang, Silin; Zhao, Ning; Zhou, Dequn; Wei, Rong; Yang, Bin; Pan, Bo

2016-04-01

The concentration and chemical speciation of arsenic (As) in different environmental matrixes (water, sediment, agricultural soils, and non-agricultural soils) were investigated in the Nanpan River area, the upstream of Pearl River, China. The results did not show any obvious transport of As along the flow direction of the river (from upstream to downstream). Total As concentrations in sediment were significantly different from those in agricultural soil. According to the comparison to quality standards, the As in sediments of the studied area have potential ecological risks and a minority of the sampling sites of agricultural soils in the studied area were polluted with As. As speciations were analyzed using sequential extraction and the percentage of non-residual fraction in sediment predominated over residual fraction. We thus believe that As in the studied area was with low mobility and bioavailability in sediment, agricultural soils, and non-agricultural soils. However, the bioavailability and mobility of As in sediment were higher than in both agricultural and non-agricultural soils, and thus, special attention should be paid for the risk assessment of As in the river in future studies.

Reciever Function Transect Across Tibet, Tarim and Tien Shan

NASA Astrophysics Data System (ADS)

Marshall, B.; Levin, V. L.; Huang, G.; Roecker, S. W.; Wang, H.

2010-12-01

We investigate the region of the ongoing collision between the India and Eurasia tectonic plates that results in widespread deformation of the continental lithosphere. Over the past decade, numerous regional studies were conducted between the Himalaya and the Tien Shan mountains, each illuminating a small part of the area. We combine the data from a number of portable and permanent networks to construct a ~1800 km long profile of lithospheric properties that cross three very different tectonic domains: the Tibetan plateau, the Tarim basin, and the Tien Shan mountains. We use data from 60 stations operated in the region by US, Chinese and French researchers. We use records of distant earthquakes to construct receiver function gathers for each station. The uniformity of processing ensures that our results are comparable along the transect. We examine receiver function gathers at each site, and rank their quality on the basis of number of records, noise levels, and directional stability of the wavefield. We select 27 sites with high-quality data. For these we construct average receiver function traces using data in the 60-85 degree range, and use them as a guide to the lithospheric layering beneath the region. On most receiver functions we constructed the most prominent feature is a positive phase likely associated with the crust-mantle transition. The timing of this phase varies significantly over the length of the profile. Beneath the Tibetan plateau delay times ~7-8 s are seen close to the Himalayas, and nearly 10 s delays are found further north. Delays of 6 to 8 s are seen beneath sites in the Tarim basin and the Tien Shan mountains, and nearly 10 s delays are seen at the border between them. In addition to the pulse associated with the crust-mantle transition we see other locally-consistent features, for example a negative phase with delay values between 3 and 5 s beneath much of the Tibetan plateau.

Distribution, sources and ecological risk assessment of PAHs in surface sediments from the Luan River Estuary, China.

PubMed

Zhang, Daolai; Liu, Jinqing; Jiang, Xuejun; Cao, Ke; Yin, Ping; Zhang, Xunhua

2016-01-15

The distribution, sources and risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) of surface sediments in the Luan River Estuary, China, have been investigated in the research. The results indicated that the total concentrations of 16 PAHs in surface sediments of the Luan River Estuary ranged from 5.1 to 545.1 ng g(-1)dw with a mean value of 120.8 ng g(-1)dw, which is relatively low in comparison with other estuaries around the world. The PAHs in the study area were mainly originated from pyrogenic sources. Besides, PAHs may be contaminated by petrogenic PAHs as indicated by the selected ratios of PAHs, the 2-tailed Pearson correlation analysis and principal components analysis at different sites. The result of the ecological risk assessment shows little negative effect for most individual PAHs in surface sediments of the Luan River Estuary, China. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessing the comprehensive restoration of an urban river: an integrated application of contingent valuation in Shanghai, China.

PubMed

Zhao, Jun; Liu, Qiuxia; Lin, Liqing; Lv, Huafang; Wang, Yao

2013-08-01

Around 2000, China began to address the comprehensive restoration of its urban rivers and attempt to restore river ecosystem services. This paper reports an integrated contingent valuation of the ecosystem services of Zhangjiabang Creek in Shanghai, which is in the most developed region of China. A total of 1440 questionnaires were delivered, and 1153 were returned as usable in August 2008. The willingness to pay for the restoration of the urban river is 20.22 RMB (2.91 USD) per month per household under the payment card and 110.64 RMB (15.92 USD) under the dichotomous format. Several important methodological issues of the contingent valuation method (CVM) are observed, including the disparity between willingness to pay and willingness to accept, the difference between payment card and dichotomous choice question formats, and the comparison of different models in welfare estimation using dichotomous choice data. Several new findings are disclosed for these three issues of CVM. Copyright © 2013 Elsevier B.V. All rights reserved.

Temporal and spatial variation of hydrological condition in the Ziwu River Basin of the Han River in China

NASA Astrophysics Data System (ADS)

Li, Ziyan; Liu, Dengfeng; Huang, Qiang; Bai, Tao; Zhou, Shuai; Lin, Mu

2018-06-01

The middle route of South-To-North Water Diversion in China transfers water from the Han River and Han-To-Wei Water Diversion project of Shaanxi Province will transfer water from the Ziwu River, which is a tributary of the Han River. In order to gain a better understanding of future changes in the hydrological conditions within the Ziwu River basin, a Mann-Kendall (M-K) trend analysis is coupled with a persistence analysis using the rescaled range analysis (R/S) method. The future change in the hydrological characteristics of the Ziwu River basin is obtained by analysing the change of meteorological factors. The results show that, the future precipitation and potential evaporation are seasonal, and the spatial variation is significant. The proportion of basin area where the spring, summer, autumn and winter precipitation is predicted to continue increase is 0.00, 100.00, 19.00 and 16.00 %, meanwhile, the proportion of basin area that will continue to decrease in the future respectively will be 100.00, 0.00, 81.00 and 74.00 %.The future potential evapotranspiration of the four seasons in the basin shows a decreasing trend. The future water supply situation in the spring and autumn of the Ziwu River basin will degrade, and the future water supply situation in the summer and winter will improve. In addition, the areas with the same water supply situation are relatively concentrated. The results will provide scientific basis for the planning and management of river basin water resources and socio-hydrological processes analysis.

Modeled effects of irrigation on surface climate in the Heihe River Basin, Northwest China

NASA Astrophysics Data System (ADS)

Zhang, Xuezhen; Xiong, Zhe; Tang, Qiuhong

2017-08-01

In Northwest China, water originates from the mountain area and is largely used for irrigation agriculture in the middle reaches. This study investigates the local and remote impact of irrigation on regional climate in the Heihe River Basin, the second largest inland river basin in Northwest China. An irrigation scheme was developed and incorporated into the Weather Research and Forecasting (WRF) model with the Noah-MP land surface scheme (WRF/Noah-MP). The effects of irrigation is assessed by comparing the model simulations with and without consideration of irrigation (hereafter, IRRG and NATU simulations, respectively) for five growth seasons (May to September) from 2009 to 2013. As consequences of irrigation, daily mean temperature decreased by 1.7°C and humidity increased by 2.3 g kg-1 (corresponding to 38.5%) over irrigated area. The temperature and humidity of IRRG simulation matched well with the observations, whereas NATU simulation overestimated temperature and underestimated humidity over irrigated area. The effects on temperature and humidity are generally small outside the irrigated area. The cooling and wetting effects have opposing impacts on convective precipitation, resulting in a negligible change in localized precipitation over irrigated area. However, irrigation may induce water vapor convergence and enhance precipitation remotely in the southeastern portion of the Heihe River Basin.

Multimedia fate modeling and risk assessment of a commonly used azole fungicide climbazole at the river basin scale in China.

PubMed

Zhang, Qian-Qian; Ying, Guang-Guo; Chen, Zhi-Feng; Liu, You-Sheng; Liu, Wang-Rong; Zhao, Jian-Liang

2015-07-01

Climbazole is an antidandruff active ingredient commonly used in personal care products, but little is known about its environmental fate. The aim of this study was to evaluate the fate of climbazole in water, sediment, soil and air compartments of the whole China by using a level III multimedia fugacity model. The usage of climbazole was calculated to be 345 t in the whole China according to the market research data, and after wastewater treatment a total emission of 245 t was discharged into the receiving environment with approximately 93% into the water compartment and 7% into the soil compartment. The developed fugacity model was successfully applied to estimate the contamination levels and mass inventories of climbazole in various environmental compartments of the river basins in China. The predicted environmental concentration ranges of climbazole were: 0.20-367 ng/L in water, and 0.009-25.2 ng/g dry weight in sediment. The highest concentration was mainly found in Haihe River basin and the lowest was in basins of Tibet and Xinjiang regions. The mass inventory of climbazole in the whole China was estimated to be 294 t, with 6.79% in water, 83.7% in sediment, 9.49% in soil, and 0.002% in air. Preliminary risk assessment showed high risks in sediment posed by climbazole in 2 out of 58 basins in China. The medium risks in water and sediment were mostly concentrated in north China. To the best of our knowledge, it is the first report on the emissions and multimedia fate of climbazole in the river basins of the whole China. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution and source analysis of aluminum in rivers near Xi'an City, China.

PubMed

Wang, Dongqi; He, Yanling; Liang, Jidong; Liu, Pei; Zhuang, Pengyu

2013-02-01

To study the status and source of aluminum (Al) contamination, a total of 21 sampling sites along six rivers near Xi'an City (Shaanxi province, China) were investigated during 2008-2010. The results indicated that the average concentration of total Al (Al(t)) in the six rivers increased by 1.6 times from 2008 to 2010. The spatial distribution of Al(t) concentrations in the rivers near Xi'an City was significantly different, ranged from 367 μg/L (Bahe River) to 1,978 μg/L (Taiping River). The Al(t) concentration was highest near an industrial area for pulp and paper-making (2,773 μg/L), where the Al level greatly exceeded the water quality criteria of both the USA (Criterion Continuous Concentration, 87 μg/L) and Canada (100 μg/L). The average concentration of inorganic monometric aluminum (Al(im)) was 72 μg/L which would pose threats to fishes and other aquatic lives in the rivers. The concentrations of exchangeable Al (Al(ex)) in the sediment of the Taiping River sampled were relatively high, making it to be an alternative explanation of increasing Al concentrations in the rivers near Xi'an City. Furthermore, an increasing Al level has been detected in the upstream watershed near Xi'an City in recent years, which might indicate another notable pollution source of Al.

Preliminary investigation on the occurrence of several sulfonamide antibiotics in the Haihe River Basin of China

NASA Astrophysics Data System (ADS)

Zhang, S. L.; Zhang, J.; Wang, Z. G.; Wang, Y. Z.; Liang, S. T.; Liu, C.; Wang, Z.

2017-08-01

Several samples collected from lakes, rivers and reservoirs in Haihe river basin of China were analyzed for 8 sulfonamide antibiotics by using solid-phase extraction and liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). All water samples were enriched with HLB extraction cartridges. The antibiotics were separated by gradient elution with methanol as the mobile phase adding 0.1% formic acid. The eluate was then analyzed by the mode of multiple reaction monitoring (MRM). The limits of detection (LOD) and quantification (LOQ) were 0.4-1.0 ng/L and 1.0-3.0 ng/L respectively. The method was used for the analysis of 13 samples from Haihe river basin in China. The results showed that sulfamethoxazole was present in all water samples with maximum concentration of 107.59 ng/L. Sulfadiazine was also frequently detected, concentrations ranging from 2.81 ng/L to 85.35 ng/L. Other sulfonamide antibiotics were not detected in most water samples, especially for those samples from drinking water resources.

Horse-mounted invaders from the Russo-Kazakh steppe or agricultural colonists from western Central Asia? A craniometric investigation of the Bronze Age settlement of Xinjiang.

PubMed

Hemphill, Brian E; Mallory, J P

2004-07-01

Numerous Bronze Age cemeteries in the oases surrounding the Täklamakan Desert of the Tarim Basin in the Xinjiang Uyghur Autonomous Region, western China, have yielded both mummified and skeletal human remains. A dearth of local antecedents, coupled with woolen textiles and the apparent Western physical appearance of the population, raised questions as to where these people came from. Two hypotheses have been offered by archaeologists to account for the origins of Bronze Age populations of the Tarim Basin. These are the "steppe hypothesis" and the "Bactrian oasis hypothesis." Eight craniometric variables from 25 Aeneolithic and Bronze Age samples, comprising 1,353 adults from the Tarim Basin, the Russo-Kazakh steppe, southern China, Central Asia, Iran, and the Indus Valley, are compared to test which, if either, of these hypotheses are supported by the pattern of phenetic affinities possessed by Bronze Age inhabitants of the Tarim Basin. Craniometric differences between samples are compared with Mahalanobis generalized distance (d2), and patterns of phenetic affinity are assessed with two types of cluster analysis (the weighted pair average linkage method and the neighbor-joining method), multidimensional scaling, and principal coordinates analysis. Results obtained by this analysis provide little support for either the steppe hypothesis or the Bactrian oasis hypothesis. Rather, the pattern of phenetic affinities manifested by Bronze Age inhabitants of the Tarim Basin suggests the presence of a population of unknown origin within the Tarim Basin during the early Bronze Age. After 1200 B.C., this population experienced significant gene flow from highland populations of the Pamirs and Ferghana Valley. These highland populations may include those who later became known as the Saka and who may have served as "middlemen" facilitating contacts between East (Tarim Basin, China) and West (Bactria, Uzbekistan) along what later became known as the Great Silk Road. Copyright

Intensified pluvial conditions during the twentieth century in the inland Heihe River Basin in arid northwestern China over the past millennium

NASA Astrophysics Data System (ADS)

Qin, Chun; Yang, Bao; Burchardt, Iris; Hu, Xiaoli; Kang, Xingcheng

2010-06-01

Past streamflow variability is of special significance in the inland river basin, i.e., the Heihe River Basin in arid northwestern China, where water shortage is a serious environmental and social problem. However, the current knowledge of issues related to regional water resources management and long-term planning and management is limited by the lack of long-term hydro-meteorological records. Here we present a 1009-year annual streamflow (August-July) reconstruction for the upstream of the Heihe River in the arid northwestern China based on a well-replicated Qilian juniper ( Sabina przewalskii Kom.) ring-width chronology. This reconstruction accounts for 46.9% of the observed instrumental streamflow variance during the period 1958-2006. Considerable multidecadal to centennial flow variations below and above the long-term average are displayed in the millennium streamflow reconstruction. These periods 1012-1053, 1104-1212, 1259-1352, 1442-1499, 1593-1739 and 1789-1884 are noteworthy for the persistence of low-level river flow, and for the fact that these low streamflow events are not found in the observed instrumental hydrological record during the recent 50 years. The 20th century witnessed intensified pluvial conditions in the upstream of the Heihe River in the arid northwestern China in the context of the last millennium. Comparison with other long-term hydrological reconstructions indicates that the intensification of the hydrological cycle in the twentieth century from different regions could be attributable to regional to large-scale temperature increase during this time. Furthermore, from a practical perspective, the streamflow reconstruction can serve as a robust database for the government to work out more scientific and more reasonable water allocation alternatives for the Heihe River Basin in arid northwestern China.

Progress and prospects of climate change impacts on hydrology in the arid region of northwest China.

PubMed

Chen, Yaning; Li, Zhi; Fan, Yuting; Wang, Huaijun; Deng, Haijun

2015-05-01

The arid region of Northwest China, located in the central Asia, responds sensitively to global climate change. Based on the newest research results, this paper analyzes the impacts of climate change on hydrology and the water cycle in the arid region of Northwest China. The analysis results show that: (1) In the northwest arid region, temperature and precipitation experienced "sharply" increasing in the past 50 years. The precipitation trend changed in 1987, and since then has been in a state of high volatility, during the 21st century, the increasing rate of precipitation was diminished. Temperature experienced a "sharply" increase in 1997; however, this sharp increasing trend has turned to an apparent hiatus since the 21st century. The dramatic rise in winter temperatures in the northwest arid region is an important reason for the rise in the average annual temperature, and substantial increases in extreme winter minimum temperature play an important role in the rising average winter temperature; (2) There was a significant turning point in the change of pan evaporation in the northwest arid area in 1993, i.e., in which a significant decline reversed to a significant upward trend. In the 21st century, the negative effects of global warming and increasing levels of evaporation on the ecology of the northwest arid region have been highlighted; (3) Glacier change has a significant impact on hydrology in the northwest arid area, and glacier inflection points have appeared in some rivers. The melting water supply of the Tarim River Basin possesses a large portion of water supplies (about 50%). In the future, the amount of surface water will probably remain at a high state of fluctuation. Copyright © 2015 Elsevier Inc. All rights reserved.

Sources identification and pollution evaluation of heavy metals in the surface sediments of Bortala River, Northwest China.

PubMed

Zhang, Zhaoyong; Juying, Li; Mamat, Zulpiya; QingFu, Ye

2016-04-01

The current study focused on the Bortala River - a typical inland river located in an oasis of arid area in northwestern China. The sediment and soil samples were collected from the river and drainage basin. Results showed that: (1) the particle size of the sand fraction of the sediments was 78-697 µm, accounting for 78.82% of the total samples; the average concentrations of eight heavy metals fell within the concentration ranges recommended by the Secondary National Standard of China, while the maximum concentrations of Pb, Cd, and Hg exceeded these standards; (2) results from multivariate statistical analysis indicated that Cu, Ni, As, and Zn originated primarily from natural geological background, while Cd, Pb, Hg and Cr in the sediments originated from human activities; (3) results of the enrichment factor analysis and the geo-accumulation index evaluation showed that Cd, Hg, and Pb were present in the surface sediments of the river at low or partial serious pollution levels, while Zn, Cr, As, Ni, and Cu existed at zero or low pollution levels; (4) calculation of the potential ecological hazards index showed that among the eight tested heavy metals, Cd, Pb, Hg, and Cr were the main potential ecological risk factors, with relative contributions of 25.43%, 22.23%, 21.16%, and 14.87%, respectively; (5) the spatial distribution of the enrichment factors (EF(S)), the Geo-accumulation index (I(geo)), and the potential ecological risk coefficient (E(r)(i)) for eight heavy metals showed that there was a greater accumulation of heavy metals Pb, Cd, and Hg in the sediments of the central and eastern parts of the river. Results of this research can be a reference for the heavy metals pollution prevention, the harmony development of the ecology protection and the economy development of the oases of inland river basin of arid regions of China, Central Asia and also other parts of the world. Copyright © 2015 Elsevier Inc. All rights reserved.

Sources and characteristics of organochlorine pesticides in the soil and sediment along the Kaidu-Peacock River, Northwest of China

NASA Astrophysics Data System (ADS)

Chen, Wei; Qi, Shihua; Peng, Fei; Qu, Chengkai; Zhang, Yuan; Xing, Xinli; Zhang, Jiaquan

2016-04-01

Organochlorine pesticides (OCPs) are a sub-group of persistent organic pollutants (POPs), which have raised the concerns from researchers all around the world for several decades. But very little research has been conducted on POPs in the arid zone of Northwest China. More than 100 soil and sediment samples were collected from Kaidu-Peacock River of Xinjiang, Northwest of China, to investigate the organochlorine pesticides (OCPs) in this region analysed by the gas chromatograph equipped with a mass selective detector (GC-MSD). Our pre-study in 2006 (Chen et al. 2011) in the same region, showed that OCPs except o,p'-DDT were detected in sediments from the Peacock River. Similar results were found in the whole river catchment in this investigation. DDTs, HCHs, chlordanes and endosulfans were the dominant OCPs residual in the soil and sediments. This study confirmed that POPs, such as OCPs in this region were contributed to by both local emissions and long-term atmospheric transport and may pose risks to human health and the ecosystem. Chen, W., Jing, M., Bu, J., Ellis Burnet, J., Qi, S., Song, Q., Ke, Y., Miao, J., Liu, M. & Yang, C. (2011) Organochlorine pesticides in the surface water and sediments from the Peacock River Drainage Basin in Xinjiang, China: a study of an arid zone in Central Asia. Environmental Monitoring and Assessment, 177, 1-21.

Driving forces and their contribution to the recent decrease in sediment flux to ocean of major rivers in China.

PubMed

Li, Tong; Wang, Shuai; Liu, Yanxu; Fu, Bojie; Zhao, Wenwu

2018-09-01

Understanding the mechanisms behind land-ocean sediment transport processes is crucial, due to the resulting impacts on the sustainable management of water and soil resources. This study investigated temporal trends and historical phases of sediment flux delivered to the sea by nine major rivers in China, while also quantifying the contribution of key anthropogenic and natural driving forces. During the past six decades, sediment flux from these nine major rivers exhibited a statistically significant negative trend, decreasing from 1.92Gtyr -1 during 1954-1968 to 1.39Gtyr -1 , 0.861Gtyr -1 and 0.335Gtyr -1 during 1969-1985, 1986-1999 and 2000-2016, respectively. We used a recently developed Sediment Identity approach and found that the sharp decrease in sediment load observed across China was mainly (~95%) caused by a reduction in sediment concentration. Reservoir construction exerted the strongest influence on land-ocean sediment fluxes, while soil conservation measures represented a secondary driver. Before 1999, soil erosion was not controlled effectively in China and reservoirs, especially large ones, played a dominant role in reducing riverine sediments. After 1999, soil erosion has gradually been brought under control across China, so that conservation measures directly accounted for ~40% of the observed decrease in riverine sediments. With intensifying human activities, it is predicted that the total sediment flux delivered to the sea by the nine major rivers will continue to decrease in the coming decades, although at a slower rate, resulting in severe challenges for the sustainable management of drainage basins and river deltas. Copyright © 2018 Elsevier B.V. All rights reserved.

Occurrence of organotins in the Yangtze River and the Jialing River in the urban section of Chongqing, China.

PubMed

Gao, Jun-Min; Zhang, Ying; Guo, Jin-Song; Jin, Fen; Zhang, Ke

2013-05-01

The occurrence of organotins in the Yangtze River and the Jialing River in the urban section of Chongqing, China and their impact on drinking water waterworks are reported in this study. Water samples were extracted by solid-phase microextraction and measured using a gas chromatograph with mass spectrometer. The results showed that the rivers studied were polluted by both butyltins and phenyltins and that the butyltin species was the dominant pollutant. Butyltins, especially monobutyltin, were detected in all 18 sampling stations, and phenyltins were detected only in 11 sampling stations. Majority of the organotins were MBTs with concentrations varying from 27.3 to 1,145.8 ng Sn L(-1). Diphenyltin and dibutyltin were the second most common with the highest levels of 113.7 and 202.5 ng Sn L(-1), respectively. Monophenyltin, tributyltin, and triphenyltin had the lowest detection rates with concentration levels of 9.7, 161.8, and 37.2 ng Sn L(-1), respectively. Some of the organotins were also detected in drinking water waterworks, which posed a threat to the water quality of Chongqing.

Impact of Yangtze River Water Transfer on the Water Quality of the Lixia River Watershed, China

PubMed Central

Ma, Xiaoxue; Wang, Lachun; Wu, Hao; Li, Na; Ma, Lei; Zeng, Chunfen; Zhou, Yi; Yang, Jun

2015-01-01

To improve water quality and reduce the negative impacts of sudden inputs of water pollution in the Lixia River watershed, China, a series of experimental water transfers from the Yangtze River to the Lixia River were conducted from 2 December 2006 to 7 January 2007. Water samples were collected every six days at 55 monitoring sites during this period. Eight water parameters (water temperature, pH, dissolved oxygen (DO), chemical oxygen demand (COD), potassium permanganate index (CODMn), ammonia nitrogen (NH4 +-N), electrical conductivity (EC), and water transparency (WT)) were analyzed to determine changes in nutrient concentrations during water transfers. The comprehensive pollution index (Pi) and single-factor (Si) evaluation methods were applied to evaluate spatio-temporal patterns of water quality during water transfers. Water quality parameters displayed different spatial and temporal distribution patterns within the watershed. Water quality was improved significantly by the water transfers, especially for sites closer to water intake points. The degree of improvement is positively related to rates of transfer inflow and drainage outflow. The effects differed for different water quality parameters at each site and at different water transfer times. There were notable decreases in NH4 +-N, DO, COD, and CODMn across the entire watershed. However, positive effects on EC and pH were not observed. It is concluded that freshwater transfers from the Yangtze River can be used as an emergency measure to flush pollutants from the Lixia River watershed. Improved understanding of the effects of water transfers on water quality can help the development and implementation of effective strategies to improve water quality within this watershed. PMID:25835525

A review of environmental and human exposure to persistent organic pollutants in the Pearl River Delta, South China.

PubMed

Zhang, Kai; Wei, Yan-Li; Zeng, Eddy Y

2013-10-01

Rapid economic growth in South China (including Guangdong Province, Hong Kong, and Macau), particularly within the Pearl River Delta region, has resulted in severe pollution of the natural eco-environment in the last three decades. Large amounts of monitoring data on organic pollution in the Pearl River Delta have been accumulated, which allows us to conduct a fairly comprehensive assessment of the state of the Pearl River Delta and elucidate spatial and temporal patterns of pollution on a regional scale. Of various causes for environmental deterioration, negative impact from persistent organic pollutants (POPs) is a global concern. This review examines the current levels and distribution patterns of several POPs, namely DDT (and its metabolites DDD and DDE), hexachlorocyclohexanes, and polybrominated diphenyl ethers, in various environmental compartments of South China. The general information on environmental occurrence, regional behaviors, ecological effects, and human exposure of these POPs in this region are reviewed. Copyright © 2012 Elsevier B.V. All rights reserved.

The spatiotemporal distribution of dissolved carbon in the main stems and their tributaries along the lower reaches of Heilongjiang River Basin, Northeast China.

PubMed

Wang, Lili; Song, Changchun; Guo, Yuedong

2016-01-01

The Heilongjiang River Basin in the eastern Siberia, one of the largest river basins draining to the North Pacific Ocean, is a border river between China, Mongolia, and Russia. In this study, we examined the spatial and seasonal variability in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved total carbon (DTC) concentrations along lower reaches of Heilongjiang River Basin, China. Water samples were collected monthly along the mouths of main rivers (Heilongjiang River, Wusuli River, and Songhua River) and their ten tributary waters for 2 years. The DOC concentrations of waters ranged from 1.74 to 16.64 mg/L, with a mean value of 8.90 ± 0.27 mg/L (n = 165). Notably, mean DIC concentrations were 9.08 ± 0.31 mg/L, accounting for 13.26∼83.27% of DTC. DIC concentrations increased significantly after the Heilongjiang River passed through Northeast China, while DOC concentrations decreased. Over 50% of DIC concentrations were decreased during exports from groundwater to rice fields and from rice fields to ditches. Water dissolved carbon showed large spatial and temporal variations during the 2-year measurement, suggesting that more frequently samplings were required. Carbon (DIC + DOC) loads from the Heilongjiang River to the Sea of Okhotsk were estimated to be 3.26 Tg C/year in this study, accounting for 0.64% of the global water dissolved carbon flux. DIC export contributed an average of 51.84% of the estimated carbon load in the Heilongjiang River, acting as an important carbon component during riverine transport. Our study could provide some guides on agricultural water management and contribute to more accurately estimate global carbon budgets.

Changing Regulations of COD Pollution Load of Weihe River Watershed above TongGuan Section, China

NASA Astrophysics Data System (ADS)

Zhu, Lei; Liu, WanQing

2018-02-01

TongGuan Section of Weihe River Watershed is a provincial section between Shaanxi Province and Henan Province, China. Weihe River Watershed above TongGuan Section is taken as the research objective in this paper and COD is chosen as the water quality parameter. According to the discharge characteristics of point source pollutions and non-point source pollutions, a method—characteristic section load (CSLD) method is suggested and point and non-point source pollution loads of Weihe River Watershed above TongGuan Section are calculated in the rainy, normal and dry season in 2013. The results show that the monthly point source pollution loads of Weihe River Watershed above TongGuan Section discharge stably and the monthly non-point source pollution loads of Weihe River Watershed above TongGuan Section change greatly and the non-point source pollution load proportions of total pollution load of COD decrease in the rainy, wet and normal period in turn.

Occurrence and sources of antibiotics and their metabolites in river water, WWTPs, and swine wastewater in Jiulongjiang River basin, south China.

PubMed

Jiang, Hongyou; Zhang, Dandan; Xiao, Shichang; Geng, Chunnv; Zhang, Xian

2013-12-01

In this study, the occurrence and sources of five cataloged antibiotics and metabolites were studied in Jiulongjiang River basin, south China. Nineteen antibiotics and 13 metabolites were detected in water samples from 16 river sampling sites, wastewater from 5 swine-raising facilities, and effluent from 5 wastewater treatment plants (WWTPs). The results showed that 12 antibiotics and 6 metabolites were detected in river water samples. Sulfonamides (SAs) and their metabolites were detected at high concentrations (8.59-158.94 ng/L). Tetracyclines (TCs) and their metabolites were frequently detected in swine wastewater, and the maximum concentration was up to the level in milligram per liter. Macrolides (MLs) and β-lactams (β-Ls) were found in all WWTP effluent samples and some river samples, while they were never found in any of the swine wastewater samples. SAs and quinolones (QNs) were detected in all samples. Hierarchical cluster analysis of 16 surface water samples was applied to achieve the spatial distribution characteristics of antibiotics in the Jiulongjiang River. As a result, two categories were obviously obtained. Principal component analysis and redundancy analysis showed that TCs and SAs as well as their metabolites were the major antibiotics in Jiulongjiang River, and they mainly originated from swine wastewater, while the QNs, MLs, and β-Ls in the Jiulongjiang River came from WWTP effluent.

Biocides in the Yangtze River of China: spatiotemporal distribution, mass load and risk assessment.

PubMed

Liu, Wang-Rong; Zhao, Jian-Liang; Liu, You-Sheng; Chen, Zhi-Feng; Yang, Yuan-Yuan; Zhang, Qian-Qian; Ying, Guang-Guo

2015-05-01

Nineteen biocides were investigated in the Yangtze River to understand their spatiotemporal distribution, mass loads and ecological risks. Fourteen biocides were detected, with the highest concentrations up to 166 ng/L for DEET in surface water, and 54.3 ng/g dry weight (dw) for triclocarban in sediment. The dominant biocides were DEET and methylparaben, with their detection frequencies of 100% in both phases. An estimate of 152 t/y of 14 biocides was carried by the Yangtze River to the East China Sea. The distribution of biocides in the aquatic environments was significantly correlated to Gross Domestic Product (GDP), total phosphorus (TP) and total nitrogen (TN), suggesting dominant input sources from domestic wastewater of the cities along the river. Risk assessment showed high ecological risks posed by carbendazim in both phases and by triclosan in sediment. Therefore, proper measures should be taken to reduce the input of biocides into the river systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of reclaimed water in the watercourse of Huai River on groundwater from Chaobai River basin, Northern China

NASA Astrophysics Data System (ADS)

Yu, Yilei; Song, Xianfang; Zhang, Yinghua; Zheng, Fandong; Liu, Licai

2017-12-01

Reclaimed water is efficient for replenishing the dry rivers in northern China, but regional groundwater may be at risk from pollution. Therefore, samples of reclaimed water, river water, and groundwater were collected at the Huai River in the Chaobai River basin in 2010. The water chemistry and isotopic compositions of the samples were analyzed in the laboratory. The reclaimed water had stable compositions of water chemistry and isotopes, and the Na·Ca-HCO3·Cl water type. The water chemistry of the river water was consistent with that of the reclaimed water. A June peak of total nitrogen was the prominent characteristic in the shallow groundwater, which also had the Na·Ca-HCO3·Cl water type. However, the water chemistry and isotopes in most of the deep groundwater remained stable, and the water type was Ca·Mg-HCO3. The amount of reclaimed water recharging the groundwater was about 2.5 × 107 m3/yr. All of the shallow groundwater was impacted by the reclaimed water, with the mixing proportion of reclaimed water ranging from 42% to 80 % in the dry season and from 20% to 86% in the wet season. Only one deep well, with proportions of 67% (dry season) and 28% (wet season), was impacted. TDS, EC, and major ions (Na, K, Cl, NH4-N, NO2-N, and NO3-N) were increased in the impacted wells.

Microplastics in freshwater river sediments in Shanghai, China: A case study of risk assessment in mega-cities.

PubMed

Peng, Guyu; Xu, Pei; Zhu, Bangshang; Bai, Mengyu; Li, Daoji

2018-03-01

Microplastics, which are plastic debris with a particle diameter of less than 5 mm, have attracted growing attention in recent years. Its widespread distributions in a variety of habitats have urged scientists to understand deeper regarding their potential impact on the marine living resources. Most studies on microplastics hitherto are focused on the marine environment, and research on risk assessment methodology is still limited. To understand the distribution of microplastics in urban rivers, this study investigated river sediments in Shanghai, the largest urban area in China. Seven sites were sampled to ensure maximum coverage of the city's central districts, and a tidal flat was also included to compare with river samples. Density separation, microscopic inspection and μ-FT-IR analysis were conducted to analyze the characteristics of microplastics and the type of polymers. The average abundance of microplastics in six river sediment samples was 802 items per kilogram of dry weight. The abundance in rivers was one to two orders of magnitude higher than in the tidal flat. White microplastic spheres were most commonly distributed in river sediments. Seven types of microplastics were identified, of which polypropylene was the most prevailing polymers presented. The study then conducted risk assessment of microplastics in sediments based on the observed results, and proposed a framework of environmental risk assessment. After reviewing waste disposal related legislation and regulations in China, this study conclude that in situ data and legitimate estimations should be incorporated as part of the practice when developing environmental policies aiming to tackle microplastic pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sustainability of Water Resources in Arid Ecosystems: A View from Hei River Basin, China (Invited)

NASA Astrophysics Data System (ADS)

Zheng, C.; Cheng, G.; Xiao, H.; Ma, R.

2009-12-01

The northwest of China is characterized by an arid climate and fragile ecosystems. With irrigated agriculture, the region is a prolific producer of cotton, wheat, and maize with some of the highest output per acre in the country. The region is also rich in ore deposits, with the reserves of numerous minerals ranked at or near the top in the country. However, the sustainability of irrigated agriculture and economic development in the region is threaten by severe eco-environmental problems resulting from both global changes and human activities, such as desertification, salinization, groundwater depletion, and dust storms. All these problems are a direct consequence of water scarcity. As global warming accelerates and rapid economic growth continues, the water shortage crisis is expected to worsen. To improve the bleak outlook for the health of ecosystem and environment in northwest China, the Chinese government has invested heavily in ecosystem restoration and watershed management in recent years. However, the effectiveness of such measures and actions depends on scientific understanding of the complex interplays among ecological, hydrological and socioeconomic factors. This presentation is intended to provide an overview of a major new research initiative supported by the National Natural Science Foundation of China to study the integration of ecological principles, hydrological processes and socioeconomic considerations toward more sustainable exploitation of surface water and groundwater resources in the Hei River Basin in northwest China. The Hei River Basin is an inland watershed located at the center of the arid region in East Asia, stretching from Qilianshan Mountains in the south to the desert in the north bordering China’s Inner Mongolia Autonomous Region and Mongolia. The total area of Hei River Basin is approximately 130,000 km2. The research initiative builds on existing research infrastructure and ecohydrological data and seeks to reveal complex

Distribution and assessment of heavy metals in the surface sediment of Yellow River, China.

PubMed

Yan, Nan; Liu, Wenbin; Xie, Huiting; Gao, Lirong; Han, Ying; Wang, Mengjing; Li, Haifeng

2016-01-01

Large amounts of heavy metals discharged by industrial cities that are located along the middle reach of Yellow River, China have detrimental impacts on both the ecological environment and human health. In this study, fourteen surface sediment samples were taken in the middle reach of the Yellow River. Contents of Zn, Pb, Ni, Cu, Cr, Cd, As were measured, and the pollution status was assessed using three widely used pollution assessment methods, including the single factor index method, Nemerow pollution index method and potential ecological risk index. The concentrations of the studied heavy metals followed the order: Zn>Cr>Cu>Ni>Pb>As>Cd. Nearly 50% of sites had Cu and Cr accumulation. The concentration of Cu at the Yiluo River exceeded the secondary standard value of the Environmental quality standard for soils. Comparison of heavy metal concentrations between this study and other selected rivers indicated that Cu and Cr may be the major pollutants in our case. The single factor index indicated that many samples were at high levels of pollution for Cu and Cd; the Nemerow pollution index indicated that the Yihe River, Luohe River, Yiluo River and Huayuankou were polluted. According to the results of potential ecological risk assessment, Cd in the tributaries of Luo River, Yihe River, and Yiluo River showed high risk toward the ecosystem and human health, Cd in Huanyuankou and Cu in Yiluo River showed a middle level of risk and other samples were at a low level of risk. Copyright © 2015. Published by Elsevier B.V.

Spatial distribution and partition of perfluoroalkyl acids (PFAAs) in rivers of the Pearl River Delta, southern China.

PubMed

Liu, Baolin; Zhang, Hong; Xie, Liuwei; Li, Juying; Wang, Xinxuan; Zhao, Liang; Wang, Yanping; Yang, Bo

2015-08-15

This study investigated the occurrence of perfluoroalkyl acids (PFAAs) in surface water from 67 sampling sites along rivers of the Pearl River Delta in southern China. Sixteen PFAAs, including perfluoroalkyl carboxylic acids (PFCAs, C5-14, C16 and C18) and perfluoroalkyl sulfonic acids (PFSAs, C4, C6, C8 and C10) were determined by high performance liquid chromatography-negative electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS). Total PFAA concentrations (∑ PFAAs) in the surface water ranged from 1.53 to 33.5 ng·L(-1) with an average of 7.58 ng·L(-1). Perfluorobutane sulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) were the three most abundant PFAAs and on average accounted for 28%, 16% and 10% of ∑ PFAAs, respectively. Higher concentrations of ∑ PFAAs were found in the samples collected from Jiangmen section of Xijiang River, Dongguan section of Dongjiang River and the Pearl River flowing the cities which had very well-developed manufacturing industries. PCA model was employed to quantitatively calculate the contributions of extracted sources. Factor 1 (72.48% of the total variance) had high loading for perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), PFBS and PFOS. For factor 2 (10.93% of the total variance), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUdA) got high loading. The sorption of PFCAs on suspended particulate matter (SPM) increased by approximately 0.1 log units for each additional CF2 moiety and that on sediment was approximately 0.8 log units lower than the SPM logKd values. In addition, the differences in the partition coefficients were influenced by the structure discrepancy of absorbents and influx of fresh river water. These data are essential for modeling the transport and environmental fate of PFAAs. Copyright © 2015 Elsevier B.V. All rights reserved.

Quaternary tectonic evolution of the Pamir-Tian Shan convergence zone, Northwest China

NASA Astrophysics Data System (ADS)

Thompson Jobe, Jessica Ann; Li, Tao; Chen, Jie; Burbank, Douglas W.; Bufe, Aaron

2017-12-01

The Pamir-Tian Shan collision zone in the western Tarim Basin, northwest China, formed from rapid and ongoing convergence in response to the Indo-Eurasian collision. The arid landscape preserves suites of fluvial terraces crossing structures active since the late Neogene that create fault and fold scarps recording Quaternary deformation. Using geologic and geomorphic mapping, differential GPS surveys of deformed terraces, and optically stimulated luminescence dating, we create a synthesis of the active structures that delineate the timing, rate, and migration of Quaternary deformation during ongoing convergence. New deformation rates on eight faults and folds, when combined with previous studies, highlight the spatial and temporal patterns of deformation within the Pamir-Tian Shan convergence zone during the Quaternary. Terraces spanning 130 to 8 ka record deformation rates between 0.1 and 5.6 mm/yr on individual structures. In the westernmost Tarim Basin, where the Pamir and Tian Shan are already juxtaposed, the fastest rates occur on actively deforming structures at the interface of the Pamir-Tian Shan orogens. Farther east, as the separation between the Pamir-Tian Shan orogens increases, the deformation has not been concentrated on a single structure, but rather has been concurrently distributed across a zone of faults and folds in the Kashi-Atushi fold-and-thrust belt and along the NE Pamir margin, where shortening rates vary on individual structures during the Quaternary. Although numerous structures accommodate the shortening and the locus of deformation shifts during the Quaternary, the total shortening across the western Tarim Basin has remained steady and approximately matches the current geodetic rate of 6-9 mm/yr.

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

NASA Astrophysics Data System (ADS)

Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

2015-05-01

Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

The Spatial and Temporal Distribution of Dissolved Organic Carbon Exported from Three Chinese Rivers to the China Sea

PubMed Central

Shi, Guohua; Peng, Changhui; Wang, Meng; Shi, Shengwei; Yang, Yanzheng; Chu, Junyao; Zhang, Junjun; Lin, Guanghui; Shen, Yan; Zhu, Qiuan

2016-01-01

The lateral transport of dissolved organic carbon (DOC) plays an important role in linking the carbon cycles of terrestrial and aquatic ecosystems. Neglecting the lateral flow of dissolved organic carbon can lead to an underestimation of the organic carbon budget of terrestrial ecosystems. It is thus necessary to integrate DOC concentrations and flux into carbon cycle models, particularly with regard to the development of models that are intended to directly link terrestrial and ocean carbon cycles. However, to achieve this goal, more accurate information is needed to better understand and predict DOC dynamics. In this study, we compiled an inclusive database of available data collected from the Yangtze River, Yellow River and Pearl River in China. The database is collected based on online literature survey and analysed by statistic method. Overall, our results revealed a positive correlation between DOC flux and discharge in all three rivers, whereas the DOC concentration was more strongly correlated with the regional net primary productivity (NPP). We estimated the total DOC flux exported by the three rivers into the China Sea to be approximately 2.73 Tg yr-1. Specifically, the annual flux of DOC from the Yangtze River, Yellow River and Pearl River was estimated to be 1.85 Tg yr-1, 0.06 Tg yr-1 and 0.82 Tg yr-1, respectively, and the average annual DOC concentrations were estimated to be 2.24 ± 0.53 mg L-1, 2.70 ± 0.38 mg L-1 and 1.51 ± 0.09 mg L-1, respectively. Seasonal variations in DOC concentrations are greatly influenced by the interaction between temperature and precipitation. NPP is significantly and positively related to the DOC concentration in the Yangtze River and the Pearl River. In addition, differences in climate and the productivity of the vegetation may influence both the flux and concentrations of DOC transported by the rivers and thus potentially affect estuarine geochemistry. PMID:27755581

Linking Monsoon Activity with River-Derived Sediment Deposition in the northern South China Sea

NASA Astrophysics Data System (ADS)

Ge, Q.; Xue, Z. G.; Liu, P.; Chu, F.

2016-02-01

Sediments retrieved from a gravity core were analyzed to examine the connection between East Asian Monsoon (EAM) and river-derived sediment deposition on the continental slope in the South China Sea since the Last Glacial Maximum. Combined clay mineralogy and grain size index analysis provided evidence of the sources of fine-grained sediment as well as for rebuilding the history of paleo-EAM. A shift of sediment source from the Pearl River to southwestern Taiwanese rivers was identified during the Holocene. The 4-8μm grain size fraction, as an environmental sensitive component and thus the EAM proxy, indicated the local deposition environment is mainly controlled by sea-level variations. And during the Holocene, the East Asian summer monsoon exhibited an in-phase relationship with East Asian winter monsoon, both following variations of the insolation intensity.

Clay mineralogy and source-to-sink transport processes of Changjiang River sediments in the estuarine and inner shelf areas of the East China Sea

NASA Astrophysics Data System (ADS)

Zhao, Yifei; Zou, Xinqing; Gao, Jianhua; Wang, Chenglong; Li, Yali; Yao, Yulong; Zhao, Wancang; Xu, Min

2018-02-01

We examined the source-to-sink sediment transport processes from the Changjiang River to the estuarine coastal shelf area by analyzing the clay mineral assemblages in suspended sediment samples from the Changjiang River catchment and surface samples from the estuarine coastal shelf area following the impoundment of the Three Gorges Dam (TGD) in 2003. The results indicate that the clay mineral compositions throughout the study area are dominated by illite, with less abundant kaolinite and chlorite and scarce smectite. The clay minerals display distinct differences in the tributaries and exhibit obvious changes in the trunk stream compared with the periods before 2003, and the source of sediment has largely shifted to the mid- to lower reaches of the river after 2003. Spatially, the clay mineral assemblages in the estuarine area define two compositionally distinct provinces. Province I covers the mud area of the Changjiang River estuary and the Zhe-Min coastal region, where sediment is primarily supplied by the Changjiang River. Province II includes part of the Changjiang River estuary and the southeastern portion of the study area, where the sediment is composed of terrestrial material from the Changjiang River and re-suspended material from the Huanghe River carried by the Jiangsu coastal current. Moreover, the other smaller rivers in China (including the Oujiang and Minjiang rivers of mainland China and the rivers of West Taiwan) also contribut sediments to the estuarine and inner shelf areas. In general, the clay mineral assemblages in the Changjiang River estuarine area are have mainly been controlled by sediment supplied from upstream of the Changjiang River tributaries. However, since the completion of the TGD in 2003, the mid- to downstream tributaries have become the main source of sediments from the Changjiang catchment into the East China Sea. These analyses further demonstrate that the coastal currents and the decrease in the sediment load of the river

Occurrence and preliminarily environmental risk assessment of selected pharmaceuticals in the urban rivers, China

PubMed Central

Zhou, Haidong; Ying, Tianqi; Wang, Xuelian; Liu, Jianbo

2016-01-01

Twelve selected pharmaceuticals including antibiotics, analgesics, antiepileptics and lipid regulators were analysed and detected in water samples collected from 18 sampling sections along the three main urban rivers in Yangpu District of Shanghai, China during four sampling campaigns. Besides, algal growth inhibition test was conducted to preliminarily assess the eco-toxicology induced by the target pharmaceuticals in the rivers. Mean levels for most of target compounds were generally below 100 ng/L at sampling sections, with the exception of caffeine and paracetamol presenting considerably high concentration. The detected pharmaceuticals in the urban rivers ranged from River could be regarded as the most polluted according to total detected pharmaceutical concentrations. The target pharmaceuticals varied and fluctuated irregularly from the upstreams to the downstreams of the three rivers, indicating the wastewater inputs from non-point sources and their individual different characteristics of transference and transportation. Preliminary eco-toxicological risk assessment showed that the presence of azithromycin, clarithromycin and caffeine may present an ecotoxicological risk in the urban rivers. For other tested pharmaceuticals the inhibition effects of single substances in the urban aquatic environment, based on the algae inhibition tests, were very imperceptible. PMID:27713558

Occurrence and preliminarily environmental risk assessment of selected pharmaceuticals in the urban rivers, China

NASA Astrophysics Data System (ADS)

Zhou, Haidong; Ying, Tianqi; Wang, Xuelian; Liu, Jianbo

2016-10-01

Twelve selected pharmaceuticals including antibiotics, analgesics, antiepileptics and lipid regulators were analysed and detected in water samples collected from 18 sampling sections along the three main urban rivers in Yangpu District of Shanghai, China during four sampling campaigns. Besides, algal growth inhibition test was conducted to preliminarily assess the eco-toxicology induced by the target pharmaceuticals in the rivers. Mean levels for most of target compounds were generally below 100 ng/L at sampling sections, with the exception of caffeine and paracetamol presenting considerably high concentration. The detected pharmaceuticals in the urban rivers ranged from River could be regarded as the most polluted according to total detected pharmaceutical concentrations. The target pharmaceuticals varied and fluctuated irregularly from the upstreams to the downstreams of the three rivers, indicating the wastewater inputs from non-point sources and their individual different characteristics of transference and transportation. Preliminary eco-toxicological risk assessment showed that the presence of azithromycin, clarithromycin and caffeine may present an ecotoxicological risk in the urban rivers. For other tested pharmaceuticals the inhibition effects of single substances in the urban aquatic environment, based on the algae inhibition tests, were very imperceptible.

Spatial and temporal variation of H and O isotopic compositions of the Xijiang River system, Southwest China.

PubMed

Han, Guilin; Lv, Pin; Tang, Yang; Song, Zhaoliang

2018-05-01

Ratios of stable isotopes of hydrogen and oxygen ( 2 H/ 1 H and 18 O/ 16 O) in river waters were measured to investigate the hydrological pathway of the Xijiang River, Southwest China. The δ 2 H and δ 18 O values of river waters exhibit significant spatial and temporal variations and the isotopic compositions vary with elevation, temperature and precipitation of the recharge area. Spatially, δ 18 O values of river waters from high mountain areas are lower than those from the lower reaches of the Xijiang River due to lower temperature and higher elevation for the recharge area. However, both 2 H and 18 O are enriched differently in river waters from the middle reaches during the high flow season, depending on the season and degree of anthropogenic disturbances (e.g. water impoundments). In contrast, deuterium excess (d-excess) values of waters from the middle reaches are substantially lower than those from the upper and lower reaches, suggesting that river waters may be resided in the reservoir and evaporation increases in the middle reaches of the Xijiang River.

Valuing trade-offs of river ecosystem services in large hydropower development in Tibet, China

NASA Astrophysics Data System (ADS)

Yu, B.; Xu, L.

2015-12-01

Hydropower development can be considered as a kind of trade-offs of ecosystem services generated by human activity for their economic and energy demand, because it can increase some river ecosystem services but decrease others. In this context, an ecosystem service trade-off framework in hydropower development was proposed in this paper. It aims to identify the ecological cost of river ecosystem and serve for the ecological compensation during hydropower development, for the hydropower services cannot completely replace the regulating services of river ecosystem. The valuing trade-offs framework was integrated by the influenced ecosystem services identification and ecosystem services valuation, through ecological monitoring and ecological economic methods, respectively. With a case study of Pondo hydropower project in Tibet, China, the valuing trade-offs of river ecosystem services in large hydropower development was illustrated. The typical ecological factors including water, sediment and soil were analyzed in this study to identify the altered river ecosystem services by Pondo hydropower project. Through the field monitoring and valuation, the results showed that the Lhasa River ecosystem services value could be changed annually by Pondo hydropower project with the increment of 5.7E+8CNY, and decrement of 5.1E+7CNY. The ecological compensation for river ecosystem should be focus on water and soil conservation, reservoir dredging and tributaries habitat protection.

Effects of Vegetation Type on Soil Carbon Dynamics Along the Kaidu River in the Yanqi Basin of Northwestern China

NASA Astrophysics Data System (ADS)

Wang, J.; Wang, X.; Wang, W.

2010-12-01

The Kaidu River originates from the central southern slopes of the Tian Shan from where it flows through the Yulduz Basin and the Yanqi Basin into Lake Bosten. There has been intensive agricultural development along the Kaidu River in the Yanqi Basin. Corn and pepper are two of the main crops. Here, we present a study includes comparisons of soil organic carbon (SOC) between typical native vegtation types (e.g., Glycyrhiza uralensis Fisch, Achnatherum splendens and Sophora alopecuroides Linn) and agricultural crops (i.e., corn and pepper). Fourteen soil pits were sampled at five depths (0-5, 5-15, 15-30, 30-50 and 50-100 cm) in August 2010 (Figure 1). Soil organic matter are determined using the traditional Walkley and Black method and Loss-on-ignition at 375°C for 17 hours. As expected, agricultural soils contain higher SOC than non-agriculatural lands. Native vegetation has various effects on vertical distribution of SOC. We discuss how root system influences SOC dynamics along the Kaidu River in the central Xinjiang, China. Fig. 1. Map of sampling sites along the Kaidu River in northwestern China.

Using runoff slope-break to determine dominate factors of runoff decline in Hutuo River Basin, North China.

PubMed

Tian, Fei; Yang, Yonghui; Han, Shumin

2009-01-01

Water resources in North China have declined sharply in recent years. Low runoff (especially in the mountain areas) has been identified as the main factor. Hutuo River Basin (HRB), a typical up-stream basin in North China with two subcatchments (Ye and Hutuo River Catchments), was investigated in this study. Mann-Kendall test was used to determine the general trend of precipitation and runoff for 1960-1999. Then Sequential Mann-Kendall test was used to establish runoff slope-break from which the beginning point of sharp decline in runoff was determined. Finally, regression analysis was done to illustrate runoff decline via comparison of precipitation-runoff correlation for the period prior to and after sharp runoff decline. This was further verified by analysis of rainy season peak runoff flows. The results are as follows: (1) annual runoff decline in the basin is significant while that of precipitation is insignificant at alpha=0.05 confidence level; (2) sharp decline in runoff in Ye River Catchment (YRC) occurred in 1968 while that in Hutuo River Catchment (HRC) occurred in 1978; (3) based on the regression analysis, human activity has the highest impact on runoff decline in the basin. As runoff slope-breaks in both Catchments strongly coincided with increase in agricultural activity, agricultural water use is considered the dominate factor of runoff decline in the study area.

Analysis of vegetation condition and its relationship with meteorological variables in the Yarlung Zangbo River Basin of China

NASA Astrophysics Data System (ADS)

Han, Xianming; Zuo, Depeng; Xu, Zongxue; Cai, Siyang; Gao, Xiaoxi

2018-06-01

The Yarlung Zangbo River Basin is located in the southwest border of China, which is of great significance to the socioeconomic development and ecological environment of Southwest China. Normalized Difference Vegetation Index (NDVI) is an important index for investigating the change of vegetation cover, which is widely used as the representation value of vegetation cover. In this study, the NDVI is adopted to explore the vegetation condition in the Yarlung Zangbo River Basin during the recent 17 years, and the relationship between NDVI and meteorological variables has also been discussed. The results show that the annual maximum value of NDVI usually appears from July to September, in which August occupies a large proportion. The minimum value of NDVI appears from January to March, in which February takes up most of the percentage. The higher values of NDVI are generally located in the lower elevation area. When the altitude is higher than 3250 m, NDVI began to decline gradually, and the NDVI became gradual stabilization as the elevation is up to 6000 m. The correlation coefficient between NDVI and precipitation in the Yarlung Zangbo River Basin is greater than that with temperature. The Hurst index of the whole basin is 0.51, indicating that the NDVI of the Yarlung Zangbo River Basin shows a weak sustainability.

Contingency table analysis of pebble lithology and roundness: A case study of Huangshui River, China and comparison to rivers in the Rocky Mountains, USA

USGS Publications Warehouse

Miao, X.; Lindsey, D.A.; Lai, Z.; Liu, Xiuying

2010-01-01

Contingency table analysis of pebble lithology and roundness is an effective way to identify the source terrane of a drainage basin and to distinguish changes in basin size, piracy, tectonism, and other events. First, the analysis to terrace gravel deposited by the Huangshui River, northeastern Tibet Plateau, China, shows statistically contrasting pebble populations for the oldest terrace (T7, Dadongling, 1.2. Ma) and the youngest terraces (T0-T3, ?. 0.15. Ma). Two fluvial processes are considered to explain the contrast in correlation between lithology and roundness in T7 gravel versus T0-T3 gravel: 1) reworking of T7 gravel into T0-T3 gravel and 2) growth in the size of the river basin between T7 and T0-T3 times. We favor growth in basin size as the dominant process, from comparison of pebble counts and contingency tables. Second, comparison of results from Huangshui River of China to three piedmont streams of the Rocky Mountains, USA highlights major differences in source terrane and history. Like Rocky Mountain piedmont gravel from Colorado examples, the Huangshui gravels show a preference (observed versus expected frequency) for rounded granite. But unlike Rocky Mountain gravel, Huangshui gravel shows a preference for angular quartzite and for rounded sandstone. In conclusion, contrasting behavior of lithologies during transport, not always apparent in raw pebble counts, is readily analyzed using contingency tables to identify the provenance of individual lithologies, including recycled clasts. Results of the analysis may help unravel river history, including changes in basin size and lithology. ?? 2009.

The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China.

PubMed

Ma, Hongbo; Nittrouer, Jeffrey A; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

2017-05-01

Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams.

The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China

PubMed Central

Ma, Hongbo; Nittrouer, Jeffrey A.; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J.; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

2017-01-01

Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams. PMID:28508078

Pharmaceuticals and personal care products (PPCPs) in urban and suburban rivers of Beijing, China: occurrence, source apportionment and potential ecological risk.

PubMed

Dai, Guohua; Wang, Bin; Fu, Chaochen; Dong, Rui; Huang, Jun; Deng, Shubo; Wang, Yujue; Yu, Gang

2016-04-01

This study analyzed 15 pharmaceuticals and personal care products (PPCPs) in two rivers with different urbanization levels in the surrounding watershed (urban and suburb) in Beijing, China. Along the rivers, effluent samples from wastewater treatment plants (WWTPs) and wastewater samples from direct discharge outlets were also collected to reveal their possible contribution to the occurrence of PPCPs in these two rivers. Among the 15 PPCPs, 14 compounds were detected with caffeine (maximum 11,900 ng L(-1)) being the dominant compound. The total concentration of the detected PPCPs in direct discharge outlets (median 4706 ng L(-1)) was much higher than that in river waters (2780 ng L(-1)) and WWTP effluents (1971 ng L(-1)). The suburban-influenced Liangshui River had significantly higher PPCP concentrations compared to the urban-influenced Qing River due to more input of untreated wastewater from direct discharge outlets. Source apportionment showed that approximately 55% of the total PPCPs were contributed by untreated wastewater in the suburban-influenced river. Finally, ecological risk assessment has been regarded as a necessary part of general research. According to the environmental risk assessment results, caffeine, trimethoprim and metoprolol were found to be the most critical compounds, due to their high risk quotient values. The results of the present study can provide useful information for future PPCP pollution control and sustainable water management in Beijing, China.

Hydrological and pollution processes in mining area of Fenhe River Basin in China.

PubMed

Yang, Yonggang; Meng, Zhilong; Jiao, Wentao

2018-03-01

The hydrological and pollution processes are an important science problem for aquatic ecosystem. In this study, the samples of river water, reservoir water, shallow groundwater, deep groundwater, and precipitation in mining area are collected and analyzed. δD and δ 18 O are used to identify hydrological process. δ 15 N-NO 3 - and δ 18 O-NO 3 - are used to identify the sources and pollution process of NO 3 - . The results show that the various water bodies in Fenhe River Basin are slightly alkaline water. The ions in the water mainly come from rock weathering. The concentration of SO 4 2- is high due to the impact of coal mining activity. Deep groundwater is significantly less affected by evaporation and human activity, which is recharged by archaic groundwater. There are recharge and discharge between reservoir water, river water, soil water, and shallow groundwater. NO 3 - is the main N species in the study area, and forty-six percent of NO 3 - -N concentrations exceed the drinking water standard of China (NO 3 - -N ≤ 10 mg/L content). Nitrification is the main forming process of NO 3 - . Denitrification is also found in river water of some river branches. The sources of NO 3 - are mainly controlled by land use type along the riverbank. NO 3 - of river water in the upper reaches are come from nitrogen in precipitation and soil organic N. River water in the lower reaches is polluted by a mixture of soil organic N and fertilizers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heavy metal pollution and health risk assessment in the Wei River in China.

PubMed

Yang, Xuefu; Duan, Jinming; Wang, Lei; Li, Wei; Guan, Jianling; Beecham, Simon; Mulcahy, Dennis

2015-03-01

From data collected monthly at 26 monitoring cross sections in the Wei River in the Shaanxi Region of China during the period 2008-2012, the temporal pollution characteristics of heavy metals (Hg, Cd, Cr(VI), Pb, and As) were analyzed based on a heavy metal pollution index (HPI). The monthly HPI values of the five heavy metals in the river fluctuated greatly in 2008 and then declined gradually with time. This general trend of reduction in HPI appears not to have a seasonal variation and most likely resulted from the continued improvement in heavy metal pollution control strategies implemented by local environmental agencies combined with a significant improvement in wastewater treatment capacities. Among the five heavy metals, Cd and Pb were below 0.1 and 3 μg L(-1), respectively, at all the sampling points in the studied areas in the year 2012. The detection rates of As, Hg, and Cr(VI) were in the order of Hg > Cr(VI) > As. Hg, Cr(VI), and As exceeded, in a month of the dry season in 2012, the standard limits for category III surface waters according to the China Environment Quality Standards for Surface Water (CEQSSW). Based on the assessment using the HPI method, the pollution status of these heavy metals in water of the Wei River in the Shaanxi Region was generally at an acceptable level, but exhibited distinctive characteristics between the main stream river and tributaries. Most of the tributaries were more seriously polluted than the main river. A health risk assessment was conducted based on the Human Health Risk Assessment (HHRA) method recommended by the United States Environmental Protection Agency (USEPA). Apart from As, the health risk for the five heavy metals in the region were at acceptable levels for drinking water sources (hazard quotient (HQ) < 1, carcinogenic risk (CR) ranged from 10(-4)-10(-6)) according to the Risk Assessment Guidance for Superfund (RAGS), USEPA. Arsenic was identified as the most important pollutant of concern

Seasonal variations of nitrogen and phosphorus retention in an agricultural drainage river in East China.

PubMed

Chen, Dingjiang; Lu, Jun; Wang, Hailong; Shen, Yena; Kimberley, Mark O

2010-02-01

Riverine retention decreases loads of nitrogen (N) and phosphorus (P) in running water. It is an important process in nutrient cycling in watersheds. However, temporal riverine nutrient retention capacity varies due to changes in hydrological, ecological, and nutrient inputs into the watershed. Quantitative information of seasonal riverine N and P retention is critical for developing strategies to combat diffuse source pollution and eutrophication in riverine and coastal systems. This study examined seasonal variation of riverine total N (TN) and total P (TP) retention in the ChangLe River, an agricultural drainage river in east China. Water quality, hydrological parameters, and hydrophyte coverage were monitored along the ChangLe River monthly during 2004-2006. Nutrient export loads (including chemical fertilizer, livestock, and domestic sources) entering the river from the catchment area were computed using an export coefficient model based on estimated nutrient sources. Riverine TN and TP retention loads (RNRL and RPRL) were estimated using mass balance calculations. Temporal variations in riverine nutrient retention were analyzed statistically. Estimated annual riverine retention loads ranged from 1,538 to 2,127 t year(-1) for RNRL and from 79.4 to 90.4 t year(-1) for RPRL. Monthly retention loads varied from 6.4 to 300.8 t month(-1) for RNRL and from 1.4 to 15.3 t month(-1) for RPRL. Both RNRL and RPRL increased with river flow, water temperature, hydrophyte coverage, monthly sunshine hours, and total TN and TP inputs. Dissolved oxygen concentration and the pH level of the river water decreased with RNRL and RPRL. Riverine nutrient retention ratios (retention as a percentage of total input) were only related to hydrophyte coverage and monthly sunshine hours. Monthly variations in RNRL and RPRL were functions of TN and TP loads. Riverine nutrient retention capacity varied with environmental conditions. Annual RNRL and RPRL accounted for 30.3-48.3% and 52

The ~2.4 Ga granitoids in the Quanji Massif，NW China: Petrogenesis and Implication for the early Paleoproterozoic Tectonics

NASA Astrophysics Data System (ADS)

Gong, S.; Chen, N.; Wang, Q.

2014-12-01

The 2.4-2.2 Ga collision-related magmatism had once been considered to be weak or lacking, and were interpreted to represent the stagnation and deceleration of plate subduction. However, large-scale intermediate to acid intrusions at 2.4-2.2 Ga are widely reported in the Trans-North China Orogen and Tarim Craton, NW China. Here we presented geochronological and geochemical and Nd-Hf isotopic studies of the Hudesheng and Delingha granitoids in the Quanji Massif, which could shed new light on the NW China and global tectonics in the Paleoproterozoic. The two granitoids are exposed in the eastern and central parts of the Quanji Massif, showing similar rock types and including mainly the syenogranitic, monzogranitic and adamellitic gneisses, with ~2.41 Ga low P/T-type amphibolite enclaves. They were formed at 2.37-2.39 Ga and underwent medium P/T-type amphibolite-facies metamorphism at ~1.95-1.90 Ga. Both granitoids have relatively high Si, K contents and FeO*/Mg, 104Ga/Al ratios, and are characterized by a relative enrichment in LILEs and LREEs, but depletion in Ba, Sr, Eu and Nb. These signatures are similar to those of the high-K calc-alkaline I-type granites, and with some geochemical features of A-type granites as well, suggesting that their formation might be related to a post-collisional setting with transition from compression to extension regimes at ~2.4 Ga. The whole-rock Nd and zircon Hf isotopes suggest important crustal growth occurred at ~2.5-2.8 Ga, and the precursor magmas of both granitoids were derived from partial melting of the Neo-Archean juvenile and ancient crustal components. Collectively, the ~2.37-2.39 Ga magmatic activities in the Quanji Massif took place right after arc-related metamorphism and arc-continent collision, thus probably making up part of the arc-related ~2.4-2.2 Ga magmatic activities, including those in the Trans-North China Orogen and Tarim Craton, NW China. This implies that a prolonged strong subduction

Aliphatic and polycyclic aromatic hydrocarbons in the Xihe River, an urban river in China's Shenyang City: distribution and risk assessment.

PubMed

Guo, Wei; He, Mengchang; Yang, Zhifeng; Lin, Chunye; Quan, Xiangchun

2011-02-28

The characteristics of petroleum hydrocarbons and the risks they pose to the ecosystem were studied in the Xihe River, which is an urban river located in Shenyang, China. High levels of aliphatic hydrocarbons (AHc) and polycyclic aromatic hydrocarbons (PAHs) were observed in the river due to the discharge of wastewater from industrial and municipal facilities for a long period of time. High-molecular-weight hydrocarbons, including unresolved complex mixtures (UCM) of n-alkanes between n-C16 and n-C32 and of PAHs with four to six rings, were the dominant hydrocarbons in the river, particularly in suspended particulate matter (SPM) and sediments. The AHc was mainly from petrogenic sources, whereas PAHs was from both pyrolytic and petrogenic source inputs. Our results suggest that there is a high risk of toxicity for the soils and groundwater of the study area. The overall toxicity in the sediments can be described using the toxic equivalent (TEQ) of dibenzo[a,h]anthracene (DBA) based on benzo(a)pyrene (TEQ(BaP)) and dioxins (TEQ(TCDD)) toxic equivalent concentrations. The TEQ values for benzo(a)pyrene (TEQ(BaP)) and dioxins (TEQ(TCDD)) presented a consistent assessment of sediment PAHs. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

Effects of climate change on hydrology and hydraulics of Qu River Basin, East China.

NASA Astrophysics Data System (ADS)

Gao, C.; Zhu, Q.; Zhao, Z.; Pan, S.; Xu, Y. P.

2015-12-01

The impacts of climate change on regional hydrological extreme events have attracted much attention in recent years. This paper aims to provide a general overview of changes on future runoffs and water levels in the Qu River Basin, upper reaches of Qiantang River, East China by combining future climate scenarios, hydrological model and 1D hydraulic model. The outputs of four GCMs BCC, BNU, CanESM and CSIRO under two scenarios RCP4.5 and RCP8.5 for 2021-2050 are chosen to represent future climate change projections. The LARS-WG statistical downscaling method is used to downscale the coarse GCM outputs and generate 50 years of synthetic precipitation and maximum and minimum temperatures to drive the GR4J hydrological model and the 1D hydraulic model for the baseline period 1971-2000 and the future period 2021-2050. Finally the POT (Peaks Over Threshold) method is applied to analyze the change of extreme events in the study area. The results show that design runoffs and water levels all indicate an increasing trend in the future period for Changshangang River, Jiangshangang River and Qu River at most cases, especially for small return periods(≤20), and for Qu River the increase becomes larger, which suggests that the risk of flooding will probably become greater and appropriate adaptation measures need to be taken.

River habitat assessment for ecological restoration of Wei River Basin, China.

PubMed

Yang, Tao; Wang, Shuo; Li, Xiaoping; Wu, Ting; Li, Li; Chen, Jia

2018-04-11

As an important composition component of river ecosystems, river habitats must undergo quality assessment to potentially provide scientific basis for river ecological restoration. Substrate composition, habitat complexity, bank erosion degree, river meandering degree, human activity intensity, vegetation buffer width, water quality, and water condition were determined as indicators for river habitat assessment. The comprehensive habitat quality index (CHQI) was established for the Wei River Basin. In addition, the indicator values were determined on the basis of a field investigation at 12 national hydrological stations distributed across the Wei, Jing, and Beiluo Rivers. The analytic hierarchy process was used to determine the indicator weights and thus distinguish the relative importance of the assessment indicator system. Results indicated that the average CHQIs for the Wei, Jing, and Beiluo Rivers were 0.417, 0.508, and 0.304, respectively. The river habitat quality for the three rivers was well. As for the whole river basin, the river habitat quality for 25% of the cross section was very well, the other 25% was well, and the 50% remaining was in critical state. The river habitat quality of the Jing River was better than that of the Wei and Beiluo Rivers.

Influence of the South-to-North Water Transfer and the Yangtze River Mitigation Projects on the water quality of Han River, China

NASA Astrophysics Data System (ADS)

Liu, W.; Kuo, Y. M.

2016-12-01

The Middle Route of China's South-to-North Water Transfer (MSNW) and Yangtze-Han River Water Diversion (YHWD) Projects have been operated since 2014, which may deteriorate water quality in Han River. The 11 water sampling sites distributed from the middle and down streams of Han River watershed were monitored monthly between July 2014 and December 2015. Factor analysis and cluster analysis were applied to investigate the major pollution types and main variables influencing water quality in Han River. The factor analysis distinguishes three main pollution types (agricultural nonpoint source, organic, and phosphorus point source pollution) affecting water quality of Han River. Cluster analysis classified all sampling sites into four groups and determined their pollution source for both Dry and Wet seasons. The sites located at central city receive point source pollution in both seasons. The water quality in downstream Han River (excluding central city sites) was influenced by nonpoint source pollution from Jianghan Plain. Variations of water qualities are associated with hydrological conditions varied from operations of engineering projects and seasonal variability especially in Dry season. Good water quality as Class III mainly occurred when flow rate is greater than 800 cms in Dry season. The low average flow rate below 583 cms will degrade water quality as Class V at almost all sites. Elevating the flow rate discharged from MSNW and YHWD Projects to Han River can avoid degrading water quality especially in low flow conditions and may decrease the probability of algal bloom occurrence in Han River. Increasing the flow rate from 400 cms to 700 cms in main Han River can obviously improve the water quality of Han River. The investigation of relationships between water quality and flow rate in both projects can provide management strategies of water quality for various flow conditions.

Emergy and Economic Evaluations of Four Fruit Production Systems on Reclaimed Wetlands Surrounding the Pearl River Estuary, China

EPA Science Inventory

Emergy and economic methods were used to evaluate and compare a traditional tropical fruit cultivation system, for bananas, and three newly introduced fruit cultivation systems, for papaya, guava and wampee, on reclaimed wetlands of the Pearl River Estuary, China. The evaluations...

Occurrences of pharmaceuticals in drinking water sources of major river watersheds, China.

PubMed

Sun, Jing; Luo, Qian; Wang, Donghong; Wang, Zijian

2015-07-01

Pharmaceuticals in drinking water sources (DWSs) have raised significant concerns for their persistent input and potential human health risks. Currently, little is known about the occurrence of pharmaceuticals in DWSs in China. In this study, a survey for multi-class pharmaceuticals in DWSs of five major river watersheds in China was conducted from 2012 to 2013. Samples were collected from 25 sampling sites in rivers and reservoirs. 135 pharmaceuticals were analyzed using solid-phase extraction and ultra-performance liquid chromatography tandem mass spectrometry. The results showed that a total of 70 pharmaceuticals were present in the samples, and the most frequently detected ones included sulfonamides, macrolides, antiepileptic drugs, anti-inflammatory drugs, and β-blockers, etc. Amongst these, maximum concentrations of lincomycin, sulfamethoxazole, acetaminophen and paraxanthine were between 44 ng/L and 134 ng/L, and those of metoprolol, diphenhydramine, venlafaxine, nalidixic acid and androstenedione were less than 1 ng/L. Concentrations of the two that were most persistent, DEET and carbamazepine, were 0.8-10.2 ng/L and 0.01-3.5 ng/L, respectively. Higher concentrations of cotinine were observed in warm season than in cold season, while concentrations of lincomycin were the opposite. In a causality analysis, the occurrence of pharmaceuticals in DWSs depends mainly on the detection limits of the methods, their usage and the persistence in the aquatic environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Solanaceae plant malformation in Chongqing City, China, reveals a pollution threat to the Yangtze River.

PubMed

Zhang, Hongbo; Liu, Guanshan; Timko, Michael P; Li, Jiana; Wang, Wenjing; Ma, Haoran

2014-10-21

Water quality is under increasing threat from industrial and natural sources of pollutants. Here, we present our findings about a pollution incident involving the tap water of Chongqing City in China. In recent years, Solanaceae plants grown in greenhouses in this city have displayed symptoms of cupped, strappy leaves. These symptoms resembled those caused by chlorinated auxinic herbicides. We have determined that these symptoms were caused by the tap water used for irrigation. Using a bioactivity-guided fractionation method, we isolated a substance with corresponding auxinic activity from the tap water. The substance was named "solanicide" because of its strong bioactivity against Solanaceae plants. Further investigation revealed that the solanicide in the water system of Chongqing City is derived from the Jialing River, a major tributary of the Yangtze River. Therefore, it is also present in the Yangtze River downstream of Chongqing after the inflow of the Jialing River. Biological analyses indicated that solanicide is functionally similar to, but distinct from, other known chlorinated auxinic herbicides. Chemical assays further showed that solanicide structurally differs from those compounds. This study has highlighted a water pollution threat to the Yangtze River and its floodplain ecosystem.

Distribution of PAEs in the middle and lower reaches of the Yellow River, China.

PubMed

Sha, Yujuan; Xia, Xinghui; Yang, Zhifeng; Huang, Gordon H

2007-01-01

Samples of water, sediment and suspended particulates were collected from 13 sites in the middle and lower reaches of the Yellow River in China. Phthalic acid esters (PAEs) concentrations in different phases of each sample were determined by Gas Chromatogram GC-FID. The results are shown as follows: (1) In the Xiao Langdi-Dongming Bridge section, PAEs concentrations in water phase from the main river ranged from 3.99 x 10(-3) to 45.45 x 10(-3) mg/L, which were similar to those from other rivers in the world. The PAEs levels in the tributaries of the Yellow River were much higher than those of the main river. (2) In the studied branches, the concentration of PAEs in sediment for Luoyang Petrochemical Channel (331.70 mg/Kg) was the highest. The concentrations of PAEs in sediment phase of the main river were 30.52 to 85.16 mg/Kg, which were much higher than those from other rivers in the world. In the main river, the concentration level of PAEs on suspended solid phases reached 94.22 mg/Kg, and it reached 691.23 mg/Kg in the Yiluo River - one tributary of the Yellow River. (3) Whether in the sediment or on the suspended solid phases, there was no significant correlation between the contents of PAEs and TOC or particle size of the solid phase; and the calculated Koc of Di (2-Ethylhexyl) Phthalate (DEHP) in the river were much less than the theoretical value, which inferred that PAEs were not on the equilibrium between water and suspended solid phases/sediment. (4) Among the measured PAEs compounds, the proportions of DEHP and di-n-butyl phthalate (DBP) were much higher than the others. The concentrations of DEHP exceeded the Quality Standard in all the main river and tributary stations except those in the Mengjin and Jiaogong Bridge of the main river. This indicates that more attention should be paid to pollution control and further assessment in understanding risks associated with human health.

Evidence on the impact of sustained exposure to air pollution on life expectancy from China's Huai River policy.

PubMed

Chen, Yuyu; Ebenstein, Avraham; Greenstone, Michael; Li, Hongbin

2013-08-06

This paper's findings suggest that an arbitrary Chinese policy that greatly increases total suspended particulates (TSPs) air pollution is causing the 500 million residents of Northern China to lose more than 2.5 billion life years of life expectancy. The quasi-experimental empirical approach is based on China's Huai River policy, which provided free winter heating via the provision of coal for boilers in cities north of the Huai River but denied heat to the south. Using a regression discontinuity design based on distance from the Huai River, we find that ambient concentrations of TSPs are about 184 μg/m(3) [95% confidence interval (CI): 61, 307] or 55% higher in the north. Further, the results indicate that life expectancies are about 5.5 y (95% CI: 0.8, 10.2) lower in the north owing to an increased incidence of cardiorespiratory mortality. More generally, the analysis suggests that long-term exposure to an additional 100 μg/m(3) of TSPs is associated with a reduction in life expectancy at birth of about 3.0 y (95% CI: 0.4, 5.6).

Reconstruction of the Paleoenvironment of the Early Cambrian Yurtus Black Shale in the Tarim Basin, Northwestern China, and Its Control on Organic Matter Accumulation

NASA Astrophysics Data System (ADS)

Li, J.; Ding, W.; Dong, L.

2017-12-01

The black shale in the early Cambrian Yurtus Formation (>521 Ma) in the Tarim basin, northwestern China, is characterized by its high TOC value (up to 16%) andgreat lateral continuity. It has been proven to be high-quality hydrocarbon source rocks. Abundant phytoplanktons and small shelly fossils have been reported from the lower Yurtus chert. However, recent biomarker discovery of aryl isoprenoid hydrocarbons suggests the existence of green sulfur bacteria, which indicates that the water column was stratified and the photic zone was prevailingly euxinic. These seemingly contradictory observations hamper our further understanding of the paleoenvironment in which the Yurtus shale was deposited and its control on the accumulation of organic matter. In this study, we systematically collected samples from the Yurtus Formation at the Kungaikuotan Section, and measured the organic carbon and nitrogen isotopic compositions and the content of trace element Barium (Ba). The strong negative excursions of nitrogen isotope ( -13‰) in the lower and upper parts of the Yurtus Formation are likely attributed to the biological activity of green and purple sulfur bacteria, which is consistent with our organic carbon isotope data as well as previous biomarker discovery. As green sulfur bacteria can only live in euxinic photic zone, it may indicate that the water column above this euxinic zone contains prolific organic matters which consume all the dissolved oxidants in surface ocean. It is well accepted that Ba flux can be used as an indicator for surface ocean primary productivity. Significant increase of barium content (from <100 to 2000 ppm) is observed at the same horizon as where the negative excursion of δ15Norg occurs, suggesting the substantive organic matter in the early Cambrian surface ocean mainly result from extremely high primary productivity. The abundant phytoplankton fossil record from this time period also supports this interpretation. In summary, high TOC in the

Assessment of Heavy Metal Pollution in Sediments of Inflow Rivers to Lake Taihu, China.

PubMed

Niu, Yong; Niu, Yuan; Pang, Yong; Yu, Hui

2015-11-01

Lake Taihu, the third-largest freshwater body in China, has many functions, including drinking water supply, flood control, cultivation, navigation, and tourism. In this study, sediment samples were collected at 31 sites from 11 inflow rivers in 2012, to investigate the distribution and concentration of heavy metals copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), and chromium (Cr), and to assess their potential ecological risk. The highest mean concentration was found for Zn, followed by Cu, Cr, Pb, and Ni. Generally, heavy metal pollution was more serious in Wu Jingang River and Caoqiao River, probably because they receive large amounts of wastewater from various local industrial enterprises. The potential ecological risk values of the heavy metals were larger than 120 in more than 25.8% of the sediment samples, indicating a very high risk. The largest ecological risk was due to copper. Furthermore, the results of a principal component analysis and subsequent analysis of variance showed that heavy metal concentrations in the sediment of inflow rivers were higher than those of the lake, which created a large hazard for the aquatic ecosystems of Lake Taihu.

Effects of damming on the distribution and methylation of mercury in Wujiang River, Southwest China.

PubMed

Zhao, Lei; Guo, Yanna; Meng, Bo; Yao, Heng; Feng, Xinbin

2017-10-01

Newly built reservoirs are regarded as sensitive ecosystem for mercury (Hg) methylation. A comprehensive study was conducted to understand the influence of damming on the distribution and methylation of Hg within a river-reservoir ecosystem in Wujiang River Basin (WRB), Southwest China. Hg species in inflow-outflow rivers of six cascade reservoirs were analyzed each month during 2006. Mean concentrations of total Hg (THg) and methylmercury (MeHg) in river water in WRB were 3.41 ± 1.98 ng L -1 and 0.15 ± 0.06 ng L -1 , respectively. THg and particulate Hg (PHg) concentrations in outflow rivers of reservoirs significantly decreased after dam construction, suggesting that a considerable amount of PHg was intercepted by way of sedimentation. However, the influence of damming on the distributions of dissolved Hg (DHg) and reactive Hg (RHg) in rivers was less pronounced. MeHg concentrations in outflow rivers of the older reservoirs significantly increased compared to inflow rivers with the maximum increasing factor of 92%, indicating the active net Hg methylation in the reservoirs. However, the difference between MeHg in inflow rivers and outflow rivers were less pronounced in the newly constructed reservoirs, indicating that these reservoirs were not active sites of Hg methylation. The construction of the cascade reservoirs resulted in the elevation of MeHg in several sections of the Wujiang River, which attributed to the net Hg methylation in reservoirs and discharge of MeHg from hypolimnion. MeHg-enriched water in outflow rivers from hypolimnetic water could be transported to downstream, posing potential threat to the aquatic food web and human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variation of phytoplankton community structure from the Pearl River estuary to South China Sea.

PubMed

Jiang, Zhao-Yu; Wang, You-Shao; Cheng, Hao; Sun, Cui-Ci; Wu, Mei-Lin

2015-10-01

The Pearl River is located in the northern part of South China Sea. The environment of the Pearl River estuary (PRE) is significantly impacted by nutrients from anthropogenic activities. Along the anthropogenic pollution gradient from the PRE to South China Sea, the phylogenetic diversity and biomass of phytoplankton was examined in relation to physic-chemical variables. The richness of rbcL gene was higher in the open sea than the estuary, while the concentration of chlorophyll a (Chl a) was higher in the estuary than in the open sea. The cluster analysis of the sequences data resulted in seven phytoplankton community types and the dominant species of phytoplankton changed from Cryptophytes and Diatoms to Prymnesiophytes and Diatoms along the gradient. The community structure of phytoplankton was shaped by nutrients and salinity. The phytoplankton biomass was significantly positively affected by phosphorus, nitrite and ammonium (P < 0.01) but negatively by salinity (P < 0.05); the phytoplankton diversity was highly positively affected by salinity (P < 0.05) but negatively by silicate and nitrate (P < 0.01; P < 0.05, respectively). Anthropogenic activities played a critical role in the phytoplankton distribution and biomass of the study area. Further research is necessary to reveal the influence mechanism of environmental factors on the phytoplankton.

Eco-Design of River Fishways for Upstream Passage: Application for Hanfeng Dam, Pengxi River, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Gary E.; Rainey, William S.

2012-05-20

This paper provides a scientific approach to eco-design of river fishways to allow upstream movement of fish past new and existing dams in China. This eco-design approach integrates principles of fish ecology/behavior and engineering, a scientific field also known as bio-engineering or eco-hydraulics. We define a fishway as a structure or mechanism to convey fish upstream past a dam. Man-made or natural stream beds can be part of the fishway mechanism. Fish include bony and non-bony fishes, and upstream passage is the concern here, not downstream passage. The problem is dams block access to upstream habitat used for spawning, rearing,more » and refuge, i.e., dams decrease habitat connectivity. A solution to alleviate this problem is to design fishways, preferably while the dam is being designed, but if necessary, as retrofits afterward to provide a route that fish can and will use to pass safely upstream without undue delay. Our eco-design approach for fishways involves eight steps: 1) identify the primary species of importance; 2) understand basic ecology and behavior of these fish; 3) characterize the environmental conditions where passage is or will be blocked; 4 identify fishway alternatives and select a preferred alternative; 5) establish eco-design criteria for the fishway, either from management agencies or, if necessary, developed specifically for the given site; 6) where needed, identify and perform research required to resolve critical uncertainties and finalize the eco-design criteria; 7) apply the eco-design criteria and site-specific considerations to design the fishway, involving peer-review by local stakeholders in the process; 8) build the fishway, monitor its effectiveness, and apply the lessons learned. Example fishways are described showing a range of eco-designs depending on the dam site and fish species of concern. We apply the eco-design principles to recommend an approach and next steps for a fishway to pass fish upstream at Hanfeng Dam, an

Distribution of Organic Carbon in the Sediments of Xinxue River and the Xinxue River Constructed Wetland, China.

PubMed

Cao, Qingqing; Wang, Renqing; Zhang, Haijie; Ge, Xiuli; Liu, Jian

2015-01-01

Wetland ecosystems are represented as a significant reservoir of organic carbon and play an important role in mitigating the greenhouse effect. In order to compare the compositions and distribution of organic carbon in constructed and natural river wetlands, sediments from the Xinxue River Constructed Wetland and the Xinxue River, China, were sampled at two depths (0-15 cm and 15-25 cm) in both upstream and downstream locations. Three types of organic carbon were determined: light fraction organic carbon, heavy fraction organic carbon, and dissolved organic carbon. The results show that variations in light fraction organic carbon are significantly larger between upstream and downstream locations than they are between the two wetland types; however, the opposite trend is observed for the dissolved organic carbon. There are no significant differences in the distribution of heavy fraction organic carbon between the discrete variables (e.g., between the two depths, the two locations, or the two wetland types). However, there are significant cross-variable differences; for example, the distribution patterns of heavy fraction organic carbon between wetland types and depths, and between wetland types and locations. Correlation analysis reveals that light fraction organic carbon is positively associated with light fraction nitrogen in both wetlands, while heavy fraction organic carbon is associated with both heavy fraction nitrogen and the moisture content in the constructed wetland. The results of this study demonstrate that the constructed wetland, which has a relatively low background value of heavy fraction organic carbon, is gradually accumulating organic carbon of different types, with the level of accumulation dependent on the balance between carbon accumulation and carbon decomposition. In contrast, the river wetland has relatively stable levels of organic carbon.

Sedimentary record and luminescence chronology of palaeoflood events along the Gold Gorge of the upper Hanjiang River, middle Yangtze River basin, China

NASA Astrophysics Data System (ADS)

Guo, Yongqiang; Huang, Chun Chang; Zhou, Yali; Pang, Jiangli; Zha, Xiaochun; Fan, Longjiang; Mao, Peini

2018-05-01

Palaeoflood slackwater deposits (SWDs) along the river banks have important implications for the reconstruction of the past hydro-climatic events. Two palaeoflood SWD beds were identified in the Holocene loess-soil sequences on the cliff river banks along the Gold Gorge of the upper Hanjiang River by field investigation and laboratory analysis. They have recorded two palaeoflood events which were dated by optically stimulated luminescence to 3.2-2.8 ka and 2.1-1.8 ka, respectively. The reliability of the ages obtained for the two events are further confirmed by the presence of archaeological remains and good regional pedostratigraphic correlation. The peak discharges of two palaeoflood events at the studied sites were estimated to be 16,560-17,930 m3/s. A correlation with the palaeoflood events identified in the other reaches shows that great floods occurred frequently during the episodes of 3200-2800 and 2000-1700 a BP along the upper Hanjiang River valley during the last 4000 years. These phases of palaeoflood events in central China are well correlated with the climatic variability identified by δ18O record in the stalagmites from the middle Yangtze River Basin and show apparent global linkages. Palaeoflood studies in a watershed scale also imply that strengthened human activities during the Shang dynasty (BCE 1600-1100) and Han dynasty (BCE206-CE265) may have caused accelerated soil erosion along the upper Hanjiang River valley.

Spatial and temporal variations of water quality in Cao-E River of eastern China.

PubMed

Chen, Ding-jiang; Lu, Jun; Yuan, Shao-feng; Jin, Shu-quan; Shen, Ye-na

2006-01-01

Evaluation and analysis of water quality variations were performed with integrated consideration of water quality parameters, hydrological-meteorologic and anthropogenic factors in Cao-E River, Zhejiang Province of China. Cao-E River system has been polluted and the water quality of some reaches are inferior to Grade V according to National Surface Water Quality Standard of China (GB2002). However, mainly polluted indices of each tributary and mainstream are different. Total nitrogen (TN) and total phosphorus (TP) in the water are the main polluted indices for mainstream that varies from 1.52 to 45.85 mg/L and 0.02 to 4.02 mg/L, respectively. TN is the main polluted indices for Sub-watershed I, II, IV and V (0.76 to 18.27 mg/L). BOD5 (0.36 to 289.5 mg/L), CODMn (0.47 to 78.86 mg/L), TN (0.74 to 31.09 mg/L) and TP (0 to 3.75 mg/L) are the main polluted indices for Sub-watershed III. There are tow pollution types along the river including nonpoint source pollution and point source pollution types. Remarkably temporal variations with a few spatial variations occur in nonpoint pollution type reaches (including mainstream, Sub-watershed I and II) that mainly drained by arable field and/or dispersive rural dwelling district, and the maximum pollutant concentration appears in flooding seasons. It implied that the runoff increases the pollutant concentration of the water in the nonpoint pollution type reaches. On the other hand, remarkably spatial variations occur in the point pollution type reaches (include Sub-watershed III, IV and V) and the maximum pollutant concentration appears in urban reaches. The runoff always decreases the pollutant concentration of the river water in the seriously polluted reaches that drained by industrial point sewage. But for the point pollution reaches resulted from centralized town domestic sewage pipeline and from frequent shipping and digging sands, rainfall always increased the concentration of pollutant (TN) in the river water too

Tectonics and distribution of gold deposits in China - An overview

USGS Publications Warehouse

Zhou, T.; Goldfarb, R.J.; Phillips, G.N.

2002-01-01

Gold exploration in China has expanded rapidly during the last two decades since a modern approach to economic development has become a national priority. China currently produces 180 tonnes (t) of gold annually, which is still significantly less than South Africa, USA, and Australia. However, China is now recognized as possessing significant gold resources in a wide range of mineral deposit types. Present estimates of gold resources in China exceed 4,500 t, which comprise 60% in gold-only deposits, more than 25% in base metal-rich skarn, porphyry, and vein deposits, and more than 10% in placer accumulations. The major gold provinces in China formed during the main episodes of Phanerozoic tectonism. Such tectonism involved interaction of China's three major Precambrian cratons, North China, Tarim, and Yangtze (or South China when combined with Cathysia block), with the Angara (or Siberian), Kazakhstan-Kyrgyzstan, and Indian cratons. Resulting collisions included deformation of accreted oceanic sequences between the cratonic blocks. The most important ore-forming orogenies were (1) the late Paleozoic Variscan (405-270 Ma), which led to amalgamation of the Angara, North China and Yangtze cratons, (2) the Indosinian (270-208 Ma), which led to the collision of North China and South China cratons, (3) the Yanshanian (208-90 Ma), which was largely influenced by the subduction of the Izanagi-Pacific plates beneath eastern China, and (4) the Himalayan (<90 Ma) indentation of the Indian continent into Eurasia. No important Precambrian gold systems are recognized in China, mainly because of reworking of exposed Precambrian rocks by these younger orogenies, but there are a few Caledonian (600-405 Ma) gold-bearing system in northern Xinjiang. Most of China's orogenic, epithermal, and Carlinlike gold deposits are in the reworkerd margins of major cratonic blocks and in metasedimentary rock-dominated fold belts adjacent to these margins. Accordingly, the major gold provinces are

Runoff projection under climate change over Yarlung Zangbo River, Southwest China

NASA Astrophysics Data System (ADS)

Xuan, Weidong; Xu, Yue-Ping

2017-04-01

The Yarlung Zangbo River is located in southwest of China, one of the major source of "Asian water tower". The river has great hydropower potential and provides vital water resource for local and downstream agricultural production and livestock husbandry. Compared to its drainage area, gauge observation is sometimes not enough for good hydrological modeling in order to project future runoff. In this study, we employ a semi-distributed hydrologic model SWAT to simulate hydrological process of the river with rainfall observation and TRMM 3B4V7 respectively and the hydrological model performance is evaluated based on not only total runoff but snowmelt, precipitation and groundwater components. Firstly, calibration and validation of the hydrological model are executed to find behavioral parameter sets for both gauge observation and TRMM data respectively. Then, behavioral parameter sets with diverse efficiency coefficient (NS) values are selected and corresponding runoff components are analyzed. Robust parameter sets are further employed in SWAT coupled with CMIP5 GCMs to project future runoff. The final results show that precipitation is the dominating contributor nearly all year around, while snowmelt and groundwater are important in the summer and winter alternatively. Also sufficient robust parameter sets help reduce uncertainty in hydrological modeling. Finally, future possible runoff changes will have major consequences for water and flood security.

Spatial distribution and speciation of mercury and methyl mercury in the surface water of East River (Dongjiang) tributary of Pearl River Delta, South China.

PubMed

Liu, Jinling; Feng, Xinbin; Zhu, Wei; Zhang, Xian; Yin, Runsheng

2012-01-01

The distribution and speciation of mercury in surface water of East River, Guangdong province, China were investigated. All told 63 water samples were collected during a bi-weekly sampling campaign from July 15th to 26th, 2009. Total mercury (THg) concentrations in water samples ranged from 11 to 49 ng/L. Maximum levels of THg were measured in the lower reaches of East River, where it passes through a major industrial area adjacent to Dongguang city. Higher ratios of dissolved mercury (THg (aq)) in proportion to THg were restricted to the downstream section of East River. Concentrations of the minor constituent methyl mercury varied in the range from 0.08 to 0.21 ng/L. On average, methyl mercury made up 0.8% and 0.56% of THg (aq) and THg, respectively. Dissolved species dominated the speciation of methyl mercury in proportions up to 81%, which may imply that methyl mercury is largely produced in situ within the river water. Environmental factors (such as water temperature, dissolved oxygen, etc.) are regarded to play an important role in Hg methylation processes were monitored and assessed. In an international perspective, East River must be classified as a polluted river with considerably sources within its industrial areas. The THg (aq) and particle mercury fluxes to the Pearl River Estuary by East River run-off were estimated to be 0.31 ± 0.11 and 0.17 ± 0.13 t/year, respectively. Hence, in total nearly 0.5 t Hg is annually released to the sea from the East River tributary.

Effects of land-use patterns on in-stream nitrogen in a highly-polluted river basin in Northeast China.

PubMed

Bu, Hongmei; Zhang, Yuan; Meng, Wei; Song, Xianfang

2016-05-15

This study investigated the effects of land-use patterns on nitrogen pollution in the Haicheng River basin in Northeast China during 2010 by conducting statistical and spatial analyses and by analyzing the isotopic composition of nitrate. Correlation and stepwise regressions indicated that land-use types and landscape metrics were correlated well with most river nitrogen variables and significantly predicted them during different sampling seasons. Built-up land use and shape metrics dominated in predicting nitrogen variables over seasons. According to the isotopic compositions of river nitrate in different zones, the nitrogen sources of the river principally originated from synthetic fertilizer, domestic sewage/manure, soil organic matter, and atmospheric deposition. Isotope mixing models indicated that source contributions of river nitrogen significantly varied from forested headwaters to densely populated towns of the river basin. Domestic sewage/manure was a major contributor to river nitrogen with the proportions of 76.4 ± 6.0% and 62.8 ± 2.1% in residence and farmland-residence zones, respectively. This research suggested that regulating built-up land uses and reducing discharges of domestic sewage and industrial wastewater would be effective methods for river nitrogen control. Copyright © 2016 Elsevier B.V. All rights reserved.

Antibiotics in riverine runoff of the Pearl River Delta and Pearl River Estuary, China: concentrations, mass loading and ecological risks.

PubMed

Xu, Weihai; Yan, Wen; Li, Xiangdong; Zou, Yongde; Chen, Xiaoxiang; Huang, Weixia; Miao, Li; Zhang, Ruijie; Zhang, Gan; Zou, Shichun

2013-11-01

Ten antibiotics belonging to three groups (macrolides, fluoroquinolones and sulfonamides) were investigated in riverine runoff of the Pearl River Delta (PRD) and Pearl River Estuary (PRE), South China for assessing the importance of riverine runoff in the transportation of contaminants from terrestrial sources to the open ocean. All antibiotics were detected in the eight outlets with concentrations ranging from 0.7 to 127 ng L(-1). The annual mass loadings of antibiotics from the PRD to the PRE and coast were 193 tons with 102 tons from the fluoroquinolone group. It showed that antibiotics decreased from the riverine outlets to the PRE and open ocean. Risk assessment showed that most of these antibiotics showed various ecological risks to the relevant aquatic organisms, in which ofloxacin (OFL), erythromycin (ETM) and ciprofloxacin (CIP) posed high ecological risks to the studied aquatic environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Response of dissolved trace metals to land use/land cover and their source apportionment using a receptor model in a subtropic river, China.

PubMed

Li, Siyue; Zhang, Quanfa

2011-06-15

Water samples were collected for determination of dissolved trace metals in 56 sampling sites throughout the upper Han River, China. Multivariate statistical analyses including correlation analysis, stepwise multiple linear regression models, and principal component and factor analysis (PCA/FA) were employed to examine the land use influences on trace metals, and a receptor model of factor analysis-multiple linear regression (FA-MLR) was used for source identification/apportionment of anthropogenic heavy metals in the surface water of the River. Our results revealed that land use was an important factor in water metals in the snow melt flow period and land use in the riparian zone was not a better predictor of metals than land use away from the river. Urbanization in a watershed and vegetation along river networks could better explain metals, and agriculture, regardless of its relative location, however slightly explained metal variables in the upper Han River. FA-MLR analysis identified five source types of metals, and mining, fossil fuel combustion, and vehicle exhaust were the dominant pollutions in the surface waters. The results demonstrated great impacts of human activities on metal concentrations in the subtropical river of China. Copyright © 2011 Elsevier B.V. All rights reserved.

Antibiotics in water and sediments of rivers and coastal area of Zhuhai City, Pearl River estuary, south China.

PubMed

Li, Si; Shi, Wanzi; Li, Huimin; Xu, Nan; Zhang, Ruijie; Chen, Xuejiao; Sun, Weiling; Wen, Donghui; He, Shanliang; Pan, Jianguo; He, Zhidong; Fan, Yingying

2018-09-15

The occurrence, spatiotemporal distribution and ecological risks of 27 antibiotics in water and sediments from rivers and coastal area of Zhuhai, Pearl River estuary, south China were investigated. Higher concentrations of antibiotics were found in river water in dry season than those in wet season (p < 0.01), especially for quinolones (QNs) (6.36-463 ng/L) and aminoglycosides (AGs) (94.9-458 ng/L). In coastal water samples, the concentrations of antibiotics were up to 419 ng/L and 357 ng/L in dry season and wet season, respectively. Higher concentrations of antibiotics in coastal sediment samples were observed in wet season compared with those in dry season (p < 0.01). This may be ascribed to the greater discharge of antibiotics from mariculture and surface sediment flushing in wet season, leading to the accumulation of polluted sediments in the estuary. Redundancy analysis showed that the concentrations of antibiotics in water were correlated with biological/chemical oxygen demand, ammonia nitrogen, and/or total nitrogen (TN). In addition, sediment organic matter (SOC) and TN strongly affected the distribution of antibiotics in sediments. Ecological risk assessment based on risk quotients (RQs) indicated that most antibiotics in water samples posed insignificant risk to fish and green algae, and insignificant to medium risk to daphnid. Copyright © 2018 Elsevier B.V. All rights reserved.

Pollution by Nonylphenol in river, tap water, and aquatic in an acid rain-plagued city in southwest China.

PubMed

Jie, Yu; Jie, Zhou; Ya, Luo; Xuesong, Yang; Jing, Yang; Yu, Yang; Jiaqi, Yang; Jie, Xu

2017-06-01

Nonylphenol (NP) has provoked much environmental concern because of their weak estrogenic activities; however, few data are available on the environmental levels of the chemical in China. Environmental or river samples were assayed for NP by high-performance liquid chromatography (HPLC) technique. The concentration for NP measured in Xiangjiang River, ranging from 0.174 to 3.411 μg/L with a mean value of 1.73 μg/L, was lower than the Water Quality Criteria for NP of the US (6.6 μg/L); however, the NP concentration was maintained at a higher level compare to the developed countries and other civil cities. NP concentration in downstream water was markedly higher than that both in midstream and upstream water. Tissue accumulation of NP was observed in aquatics. A ratio of mean concentration of NP in aquatic (chlamys farreri and hemiculter leucisculus) to that in river water was 241 and 1087, respectively. The presence of NP in tap water in two urban districts of Zunyi was common with a detectable rate reached 100.0%. Mean NP concentration in terminal tap water in Huichuan district was six times as high as Honghuagang district, which was above Standards for the Drinking Water Quality for Phenols of China (2 μg/L). The pollution of NP in Xiangjiang River, tap water, and aquatic in Zunyi belongs to moderate or severe level in the world.

[Variation trends of natural vegetation net primary productivity in China under climate change scenario].

PubMed

Zhao, Dong-sheng; Wu, Shao-hong; Yin, Yun-he

2011-04-01

Based on the widely used Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ) for climate change study, and according to the features of natural environment in China, the operation mechanism of the model was adjusted, and the parameters were modified. With the modified LPJ model and taking 1961-1990 as baseline period, the responses of natural vegetation net primary productivity (NPP) in China to climate change in 1991-2080 were simulated under the Special Report on Emissions Scenarios (SRES) B2 scenario. In 1961-1990, the total NPP of natural vegetation in China was about 3.06 Pg C a(-1); in 1961-2080, the total NPP showed a fluctuant decreasing trend, with an accelerated decreasing rate. Under the condition of slight precipitation change, the increase of mean air temperature would have definite adverse impact on the NPP. Spatially, the NPP decreased from southeast coast to northwest inland, and this pattern would have less variation under climate change. In eastern China with higher NPP, especially in Northeast China, east of North China, and Loess Plateau, the NPP would mainly have a decreasing trend; while in western China with lower NPP, especially in the Tibetan Plateau and Tarim Basin, the NPP would be increased. With the intensive climate change, such a variation trend of NPP would be more obvious.

Characterization of heavy metal concentrations in the sediments of three freshwater rivers in Huludao City, Northeast China.

PubMed

Zheng, Na; Wang, Qichao; Liang, Zhongzhu; Zheng, Dongmei

2008-07-01

Wuli River, Cishan River, and Lianshan River are three freshwater rivers flowing through Huludao City, in a region of northeast China strongly affected by industrialization. Contamination assessment has never been conducted in a comprehensive way. For the first time, the contamination of three rivers impacted by different sources in the same city was compared. This work investigated the distribution and sources of Hg, Pb, Cd, Zn and Cu in the surface sediments of Wuli River, Cishan River, and Lianshan River, and assessed heavy metal toxicity risk with the application of two different sets of Sediment Quality Guideline (SQG) indices (effect range low/effect range median values, ERL/ERM; and threshold effect level/probable effect level, TEL/PEL). Furthermore, this study used a toxic unit approach to compare and gauge the individual and combined metal contamination for Hg, Pb, Cd, Zn and Cu. Results showed that Hg contamination in the sediments of Wuli River originated from previous sediment contamination of the chlor-alkali producing industry, and Pb, Cd, Zn and Cu contamination was mainly derived from atmospheric deposition and unknown small pollution sources. Heavy metal contamination to Cishan River sediments was mainly derived from Huludao Zinc Plant, while atmospheric deposition, sewage wastewater and unknown small pollution were the primary sources for Lianshan River. The potential acute toxicity in sediment of Wuli River may be primarily due to Hg contamination. Hg is the major toxicity contributor, accounting for 53.3-93.2%, 7.9-54.9% to total toxicity in Wuli River and Lianshan River, respectively, followed by Cd. In Cishan River, Cd is the major sediment toxicity contributor, however, accounting for 63.2-66.9% of total toxicity.

Distribution and pollution, toxicity and risk assessment of heavy metals in sediments from urban and rural rivers of the Pearl River delta in southern China.

PubMed

Xiao, Rong; Bai, Junhong; Huang, Laibin; Zhang, Honggang; Cui, Baoshan; Liu, Xinhui

2013-12-01

Sediments were collected from the upper, middle and lower reaches of both urban and rural rivers in a typical urbanization zone of the Pearl River delta. Six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) were analyzed in all sediment samples, and their spatial distribution, pollution levels, toxicity and ecological risk levels were evaluated to compare the characteristics of heavy metal pollution between the two rivers. Our results indicated that the total contents of the six metals in all samples exceeded the soil background value in Guangdong province. Based on the soil quality thresholds of the China SEPA, Cd levels at all sites exceeded class III criteria, and other metals exhibited pollution levels exceeding class II or III criteria at both river sites. According to the sediment quality guidelines of the US EPA, all samples were moderately to heavily polluted by Cr, Cu, Ni, Pb and Zn. Compared to rural river sites, urban river sites exhibited heavier pollution. Almost all sediment samples from both rivers exhibited moderate to serious toxicity to the environment, with higher contributions from Cr and Ni. A "hot area" of heavy metal pollution being observed in the upper and middle reaches of the urban river area, whereas a "hot spot" was identified at a specific site in the middle reach of the rural river. Contrary metal distribution patterns were also observed along typical sediment profiles from urban and rural rivers. However, the potential ecological risk indices of rural river sediments in this study were equal to those of urban river sediments, implying that the ecological health issues of the rivers in the undeveloped rural area should also be addressed. Sediment organic matter and grain size might be important factors influencing the distribution profiles of these heavy metals.

Heavy metal fractions and ecological risk assessment in sediments from urban, rural and reclamation-affected rivers of the Pearl River Estuary, China.

PubMed

Zhang, Guangliang; Bai, Junhong; Xiao, Rong; Zhao, Qingqing; Jia, Jia; Cui, Baoshan; Liu, Xinhui

2017-10-01

Rapid urbanization and reclamation processes in coastal areas have resulted in serious pollution to the aquatic environment. Less is known on the geochemical fractions and ecological risks in river sediment under various human activities pressures, which is essential for addressing the connections between heavy metal pollution and anthropogenic influences. River sediments were collected from different landscapes (i.e., urban, rural and reclamation areas) to investigate the impacts of urbanization and reclamation on the metallic pollution levels and ecological risks in the Pear River Estuary of China. Results showed that Cd, Zn and Cu with high total contents and geoaccumulation index (I geo ) were the primary metals in the Peal River sediments. Generally, urban river sediments, especially the surface sediment layer (0-10 cm), exhibited higher metallic pollution levels. As for geochemical fractions, reducible and residual fractions were the dominant forms for six determined metals. And the percentage of heavy metals bound to Fe-Mn oxides decreased with increasing soil depth but the reverse tendency was observed for residual fractions. Compared with rural river sediments, heavy metals were highly associated with the exchangeable and carbonate fractions in both urban and reclamation-affected river sediments, suggesting that anthropogenic activities mainly increased the active forms of metals. Approximately 80% of Cd existed in the non-residual fraction and posed medium to high ecological risk according to the risk assessment code (RAC) values. The redundancy analysis (RDA) revealed that both urbanization and reclamation processes would cause similar metallic characteristics, and sediment organic matter (SOC) might be the prominent influencing factor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Managing the three-rivers headwater region, china: from ecological engineering to social engineering.

PubMed

Fang, Yiping

2013-09-01

The three-rivers headwater region (THRHR) of Qinghai province, China plays a key role as source of fresh water and ecosystem services for central and eastern China. Global warming and human activities in the THRHR have threatened the ecosystem since the 1980s. Therefore, the Chinese government has included managing of the THRHR in the national strategy since 2003. The State Integrated Test and Demonstration Region of the THRHR highlights the connection with social engineering (focus on improving people's livelihood and well-being) in managing nature reserves. Based on this program, this perspective attempts a holistic analysis of the strategic role of the THRHR, requirements for change, indices of change, and approaches to change. Long-term success of managing nature reserves requires effective combination of ecological conservation, economic development, and social progress. Thus, the philosophy of social engineering should be employed as a strategy to manage the THRHR.

Occurrence and partitioning of bisphenol analogues in water and sediment from Liaohe River Basin and Taihu Lake, China.

PubMed

Jin, Hangbiao; Zhu, Lingyan

2016-10-15

Bisphenol analogues are widely used in the manufacture of polycarbonate plastics and epoxy resins, and the demand and production capacity of these compounds are growing rapidly in China. The occurrence and distribution of bisphenol analogues other than bisphenol A (BPA) in the aquatic environment is still poorly understood. In this study, nine bisphenol analogues were measured in water and sediment samples from Taihu Lake (TL), Liaohe River basin, including Liaohe River (LR) and Hunhe River (HR), China. Water samples from LR and HR contained much higher total bisphenols (∑BPs) concentrations. BPA and bisphenol S (BPS) were predominant with a summed contribution of 55, 75, and 75% to the ∑BPs in TL, LR, and HR waters, respectively. This suggests that BPA and BPS were the most widely used and manufactured bisphenols in these regions. In sediment, BPA was always predominant, with the next abundant compound bisphenol F (BPF) in TL and HR sediment, but BPS in LR sediment. The average field sediment-water partitioning coefficients (log Koc) were calculated for the first time for certain bisphenols and were determined to be 4.7, 4.6, 3.8, 3.7, and 3.5 mL/g for BPF, BPAP, BPA, BPAF, and BPS, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution of Organic Carbon in the Sediments of Xinxue River and the Xinxue River Constructed Wetland, China

PubMed Central

Cao, Qingqing; Wang, Renqing; Zhang, Haijie; Ge, Xiuli; Liu, Jian

2015-01-01

Wetland ecosystems are represented as a significant reservoir of organic carbon and play an important role in mitigating the greenhouse effect. In order to compare the compositions and distribution of organic carbon in constructed and natural river wetlands, sediments from the Xinxue River Constructed Wetland and the Xinxue River, China, were sampled at two depths (0–15 cm and 15–25 cm) in both upstream and downstream locations. Three types of organic carbon were determined: light fraction organic carbon, heavy fraction organic carbon, and dissolved organic carbon. The results show that variations in light fraction organic carbon are significantly larger between upstream and downstream locations than they are between the two wetland types; however, the opposite trend is observed for the dissolved organic carbon. There are no significant differences in the distribution of heavy fraction organic carbon between the discrete variables (e.g., between the two depths, the two locations, or the two wetland types). However, there are significant cross-variable differences; for example, the distribution patterns of heavy fraction organic carbon between wetland types and depths, and between wetland types and locations. Correlation analysis reveals that light fraction organic carbon is positively associated with light fraction nitrogen in both wetlands, while heavy fraction organic carbon is associated with both heavy fraction nitrogen and the moisture content in the constructed wetland. The results of this study demonstrate that the constructed wetland, which has a relatively low background value of heavy fraction organic carbon, is gradually accumulating organic carbon of different types, with the level of accumulation dependent on the balance between carbon accumulation and carbon decomposition. In contrast, the river wetland has relatively stable levels of organic carbon. PMID:26230255

Occurrence and transport of 17 perfluoroalkyl acids in 12 coastal rivers in south Bohai coastal region of China with concentrated fluoropolymer facilities.

PubMed

Wang, Pei; Lu, Yonglong; Wang, Tieyu; Fu, Yaning; Zhu, Zhaoyun; Liu, Shijie; Xie, Shuangwei; Xiao, Yang; Giesy, John P

2014-07-01

Perfluoroalkyl acids (PFAAs) are emerging contaminants that have raised great concern in recent years. While PFAAs manufacturing becomes regulated in developed countries, production has been partly shifted to China. Eight fluoropolymer manufacturing facilities located in the South Bohai coastal region, one of the most populated areas of China, have been used to manufacture PFAA-related substances since 2001. The environmental consequence of the intensive production of PFAAs in this region remains largely unknown. We analyzed 17 PFAAs in twelve coastal rivers of this region, and found staggeringly high concentrations of perfluorooctanoic acid (PFOA) ranging from 0.96 to 4534.41 ng/L. The highest concentration was observed in the Xiaoqing River which received effluents from certain fluoropolymer facilities. Principal component analysis indicated similar sources of several perfluoroalkyl carboxylic acids (PFCAs) in all rivers, which indicated that atmospheric transport, wastewater treatment and surface runoff also acted as important supplements to direct discharge to surface water. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of agricultural practice on trace metals in soils and vegetation in the water conservation area along the East River (Dongjiang River), South China.

PubMed

Luo, Chunling; Yang, Renxiu; Wang, Yan; Li, Jun; Zhang, Gan; Li, Xiangdong

2012-08-01

Dongjiang (East River) is the key resource of potable water for the Pearl River Delta region, South China. Although industrial activities are limited in the water conservation area along this river, agriculture is very intensive. The present study evaluated trace metals in four soils under different cultivation. The total concentrations of trace metals decreased in the order orchard soil>vegetable soil>paddy soil>natural soil, reflecting decreasing inputs of agrochemicals to soils. Relatively high concentrations of Cd were recorded in the 60-cm soil profiles. The (206)Pb/(207)Pb ratio in the above-ground tissues of plant was significantly lower than their corresponding soils. In combination with the low transfer factor of Pb from soil to plant shoots, atmospheric deposition is probably a major pathway for Pb to enter plant leaves. Regular monitoring on the soil quality in this area is recommended for the safety of water resource and agricultural products. Copyright © 2012 Elsevier B.V. All rights reserved.

Red River barrier and Pleistocene climatic fluctuations shaped the genetic structure of Microhyla fissipes complex (Anura: Microhylidae) in southern China and Indochina

PubMed Central

Yuan, Zhi-Yong; Suwannapoom, Chatmongkon; Yan, Fang; Poyarkov, Nikolay A.; Nguyen, Sang Ngoc; Chen, Hong-man; Chomdej, Siriwadee; Murphy, Robert W.

2016-01-01

South China and Indochina host striking species diversity and endemism. Complex tectonic and climatic evolutions appear to be the main drivers of the biogeographic patterns. In this study, based on the geologic history of this region, we test 2 hypotheses using the evolutionary history of Microhyla fissipes species complex. Using DNA sequence data from both mitochondrial and nuclear genes, we first test the hypothesis that the Red River is a barrier to gene flow and dispersal. Second, we test the hypothesis that Pleistocene climatic cycling affected the genetic structure and population history of these frogs. We detect 2 major genetic splits that associate with the Red River. Time estimation suggests that late Miocene tectonic movement associated with the Red River drove their diversification. Species distribution modeling (SDM) resolves significant ecological differences between sides of the Red River. Thus, ecological divergence also probably promoted and maintained the diversification. Genogeography, historical demography, and SDM associate patterns in southern China with climate changes of the last glacial maximum (LGM), but not Indochina. Differences in geography and climate between the 2 areas best explain the discovery. Responses to the Pleistocene glacial–interglacial cycling vary among species and regions. PMID:29491943

Red River barrier and Pleistocene climatic fluctuations shaped the genetic structure of Microhyla fissipes complex (Anura: Microhylidae) in southern China and Indochina.

PubMed

Yuan, Zhi-Yong; Suwannapoom, Chatmongkon; Yan, Fang; Poyarkov, Nikolay A; Nguyen, Sang Ngoc; Chen, Hong-Man; Chomdej, Siriwadee; Murphy, Robert W; Che, Jing

2016-12-01

South China and Indochina host striking species diversity and endemism. Complex tectonic and climatic evolutions appear to be the main drivers of the biogeographic patterns. In this study, based on the geologic history of this region, we test 2 hypotheses using the evolutionary history of Microhyla fissipes species complex. Using DNA sequence data from both mitochondrial and nuclear genes, we first test the hypothesis that the Red River is a barrier to gene flow and dispersal. Second, we test the hypothesis that Pleistocene climatic cycling affected the genetic structure and population history of these frogs. We detect 2 major genetic splits that associate with the Red River. Time estimation suggests that late Miocene tectonic movement associated with the Red River drove their diversification. Species distribution modeling (SDM) resolves significant ecological differences between sides of the Red River. Thus, ecological divergence also probably promoted and maintained the diversification. Genogeography, historical demography, and SDM associate patterns in southern China with climate changes of the last glacial maximum (LGM), but not Indochina. Differences in geography and climate between the 2 areas best explain the discovery. Responses to the Pleistocene glacial-interglacial cycling vary among species and regions.

Geochemistry of dissolved trace elements and heavy metals in the Dan River Drainage (China): distribution, sources, and water quality assessment.

PubMed

Meng, Qingpeng; Zhang, Jing; Zhang, Zhaoyu; Wu, Tairan

2016-04-01

Dissolved trace elements and heavy metals in the Dan River drainage basin, which is the drinking water source area of South-to-North Water Transfer Project (China), affect large numbers of people and should therefore be carefully monitored. To investigate the distribution, sources, and quality of river water, this study integrating catchment geology and multivariate statistical techniques was carried out in the Dan River drainage from 99 river water samples collected in 2013. The distribution of trace metal concentrations in the Dan River drainage was similar to that in the Danjiangkou Reservoir, indicating that the reservoir was significantly affected by the Dan River drainage. Moreover, our results suggested that As, Sb, Cd, Mn, and Ni were the major pollutants. We revealed extremely high concentrations of As and Sb in the Laoguan River, Cd in the Qingyou River, Mn, Ni, and Cd in the Yinhua River, As and Sb in the Laojun River, and Sb in the Dan River. According to the water quality index, water in the Dan River drainage was suitable for drinking; however, an exposure risk assessment model suggests that As and Sb in the Laojun and Laoguan rivers could pose a high risk to humans in terms of adverse health and potential non-carcinogenic effects.

Increased levels of antibiotic resistance in urban stream of Jiulongjiang River, China.

PubMed

Ouyang, Wei-Ying; Huang, Fu-Yi; Zhao, Yi; Li, Hu; Su, Jian-Qiang

2015-07-01

The rapid global urbanization and other extensive anthropogenic activities exacerbated the worldwide human health risks induced by antibiotic resistance genes (ARGs). Knowledge of the origins and dissemination of ARGs is essential for understanding modern resistome, while little information is known regarding the overall resistance levels in urban river. In this study, the abundance of multi-resistant bacteria (MRB) and ARGs was investigated using culture-based method and high-throughput qPCR in water samples collected from urban stream and source of Jiulongjiang River, China, respectively. The abundance of MRB (conferring resistance to three combinations of antibiotics and vancomycin) was significantly higher in urban samples. A total of 212 ARGs were detected among all the water samples, which encoded resistance to almost all major classes of antibiotics and encompassed major resistant mechanisms. The total abundance of ARGs in urban samples (ranging from 9.72 × 10(10) to 1.03 × 10(11) copies L(-1)) was over two orders of magnitude higher than that in pristine samples (7.18 × 10(8) copies L(-1)), accompanied with distinct ARGs structures, significantly higher diversity, and enrichment of ARGs. Significant correlations between the abundance of ARGs and mobile genetic elements (MGEs) were observed, implicating the potential of horizontal transfer of ARGs. High abundance and enrichment of diverse ARGs and MGEs detected in urban river provide evidence that anthropogenic activities are responsible for the emergence and dissemination of ARGs to the urban river and management options should be taken into account for minimizing the spread of ARGs.

Spatial and temporal variations of water quality in an artificial urban river receiving WWTP effluent in South China.

PubMed

Zhang, Di; Tao, Yi; Liu, Xiaoning; Zhou, Kuiyu; Yuan, Zhenghao; Wu, Qianyuan; Zhang, Xihui

2016-01-01

Urban wastewater treatment plant (WWTP) effluent as reclaimed water provides an alternative water resource for urban rivers and effluent will pose a significant influence on the water quality of rivers. The objective of this study was to investigate the spatial and temporal variations of water quality in XZ River, an artificial urban river in Shenzhen city, Guangdong Province, China, after receiving reclaimed water from WWTP effluent. The water samples were collected monthly at different sites of XZ River from April 2013 to September 2014. Multivariate statistical techniques and a box-plot were used to assess the variations of water quality and to identify the main pollution factor. The results showed the input of WWTP effluent could effectively increase dissolved oxygen, decrease turbidity, phosphorus load and organic pollution load of XZ River. However, total nitrogen and nitrate pollution loads were found to remain at higher levels after receiving reclaimed water, which might aggravate eutrophication status of XZ River. Organic pollution load exhibited the lowest value on the 750 m downstream of XZ River, while turbidity and nutrient load showed the lowest values on the 2,300 m downstream. There was a higher load of nitrogen and phosphorus pollution in the dry season and at the beginning of wet season.

Carbon dioxide and methane dynamics in a human-dominated lowland coastal river network (Shanghai, China)

NASA Astrophysics Data System (ADS)

Yu, Zhongjie; Wang, Dongqi; Li, Yangjie; Deng, Huanguang; Hu, Beibei; Ye, Mingwu; Zhou, Xuhui; Da, Liangjun; Chen, Zhenlou; Xu, Shiyuan

2017-07-01

Evasion of carbon dioxide (CO2) and methane (CH4) in streams and rivers play a critical role in global carbon (C) cycle, offsetting the C uptake by terrestrial ecosystems. However, little is known about CO2 and CH4 dynamics in lowland coastal rivers profoundly modified by anthropogenic perturbations. Here we report results from a long-term, large-scale study of CO2 and CH4 partial pressures (pCO2 and pCH4) and evasion rates in the Shanghai river network. The spatiotemporal variabilities of pCO2 and pCH4 were examined along a land use gradient, and the annual CO2 and CH4 evasion were estimated to assess its role in regional C budget. During the study period (August 2009 to October 2011), the overall mean pCO2 and median pCH4 from 87 surveyed rivers were 5846 ± 2773 μatm and 241 μatm, respectively. Internal metabolic CO2 production and dissolved inorganic carbon input via upstream runoff were the major sources sustaining the widespread CO2 supersaturation, coupling pCO2 to biogeochemical and hydrological controls, respectively. While CH4 was oversaturated throughout the river network, CH4 hot spots were concentrated in the small urban rivers and highly discharge-dependent. The Shanghai river network played a disproportionately important role in regional C budget, offsetting up to 40% of the regional terrestrial net ecosystem production and 10% of net C uptake in the river-dominated East China Sea fueled by anthropogenic nutrient input. Given the rapid urbanization in global coastal areas, more research is needed to quantify the role of lowland coastal rivers as a major landscape C source in global C budget.

Application of HEC-RAS for flood forecasting in perched river-A case study of hilly region, China

NASA Astrophysics Data System (ADS)

Sun, Pingping; Wang, Shuqian; Gan, Hong; Liu, Bin; Jia, Ling

2017-04-01

Flooding in small and medium rivers are seriously threatening the safety of human beings’ life and property. The simulation forecasting of the river flood and bank risk in hilly region has gradually become a hotspot. At present, there are few studies on the simulation of hilly perched river, especially in the case of lacking section flow data. And the method of how to determine the position of the levee breach along the river bank is not much enough. Based on the characteristics of the sections in hilly perched river, an attempt is applied in this paper which establishes the correlation between the flow profile computed by HEC-RAS model and the river bank. A hilly perched river in Lingshi County, Shanxi Province of China, is taken as the study object, the levee breach positions along the bank are simulated under four different design storm. The results show that the flood control standard of upper reach is high, which can withstand the design storm of 100 years. The current standard of lower reach is low, which is the flooding channel with high frequency. As the standard of current channel between the 2rd and the 11th section is low, levee along that channel of the river bank is considered to be heighten and reinforced. The study results can provide some technical support for flood proofing in hilly region and some reference for the reinforcement of river bank.

Chemical characteristics of PM2.5 during summer at a background site of the Yangtze River Delta in China

NASA Astrophysics Data System (ADS)

Liang, Linlin; Engling, Guenter; Zhang, Xiaoye; Sun, Junying; Zhang, Yangmei; Xu, Wanyun; Liu, Chang; Zhang, Gen; Liu, Xuyan; Ma, Qianli

2017-12-01

With rapid economic development and urbanization, particular attention has been paid to atmospheric chemical studies in the Yangtze River Delta in China. PM2.5 samples were collected by a MiniVol™ air sampler in summer time at a background site of the Yangtze River Delta in China. Carbonaceous components, i.e., OC and EC, levoglucosan and water-soluble inorganic ions, including sulfate, nitrate, ammonium, etc., were quantified. The average concentration of PM2.5 in summer at Lin'an was 30.19 ± 8.86 μg m-3, lower than previous studies reported, confirming that air pollution in China is improving, e.g., by emission control measures and subsequent reduction in PM emissions in China. Investigating the relationship among sulfate, nitrate and ammonium showed that SO42- existed as (NH4)2SO4, while NO3- may have been present as NaNO3 and KNO3. Based on molecular tracers, synoptic data as well as air mass back trajectory analysis, it was revealed that regional transport and stable synoptic conditions both play an important role in controlling the variations of aerosol chemical components. The comparison of chemical species between clean and hazy days showed that secondary organic and inorganic aerosols have different production processes. Secondary organic carbon (SOC) was much more important during clean days, while secondary inorganic aerosol species were readily produced and consequently became more important during polluted periods in Lin'an during summer time.

Sources and mass fluxes of the main contaminants in a heavily polluted and modified river of the North China Plain.

PubMed

Li, Wenzan; Li, Xuyong; Su, Jingjun; Zhao, Hongtao

2014-04-01

Many rivers in China and other newly industrialized countries have suffered from severe degradation of water quality in the context of rapid economic growth. An accounting method was developed to investigate the source and mass fluxes of the main contaminants in the Ziya River, a severely polluted and heavily modified river in a semiarid area of the North China Plain, where chemical oxygen demand (COD) and ammonia nitrogen (NH4-N) were the most important indicators of pollution. The results showed that the urban sewage with high concentration of COD and NH4-N dominated the streams, contributing to 80.7 % of the streamflow, 92.2 % of COD, and 94.5 % of NH4-N. The concentrations of COD and NH4-N in streams varied from 24.0-195.0 to 5.8-43.8 mg/L, respectively. Mass fluxes of COD and NH4-N of all pathways were quantified. Much of the polluted water was diverted to irrigation, and some eventually flowed into the Bohai Sea. Installation of adequate wastewater treatment facilities and making strict discharge standards can help improve the water quality. Our findings imply that a simple accounting method provides an extremely well-documented example for load estimation and can be useful for intervention strategies in heavily polluted and modified rivers in newly industrialized countries.

Desert disturbance assessments of regional oil exploitation by Aster and ETM+ images in Taklimakan Desert China.

PubMed

Ouyang, Wei; Hao, Fang-Hua; Fu, Yongshuo; Zhang, Jiaxun

2008-09-01

To feed its rapidly growing energy demand, oil exploitation in China has never been more intensive. The most obvious characteristics of oil exploitation are progressive and regional, which can be monitored by remote sensing, such as land use and cover change, either perpetual or temporary, during oil field development such as construction of oil well, roads, transportation systems and other facilities. In this paper, the oil field located on the north edge of Taklimakan Desert, in the Tarim River watershed in northwest of China. The disturbance effects of regional oil exploitation were the main content of regional environmental managements and monitoring. Based on Enhanced Thematic Mapper Plus (ETM+) and Aster images, analyzed regional land use and landscape change from 2001 to 2003. By the comparison, it can be concluded that the ecological quality was deteriorating in these 3 years. The woodland was degrading to grass and desert. The area of woodland dropped from 9.06 km(2) in 2001 to 3.24 km(2) in 2003 with a 64.23% decrease. At the same time, the area of shrubbery lessened 18.23%. On the other hand, the whole area of desert and Saline soils inflated from 15.08 km(2) in 2001 to 25.36 km(2) in 2003. The patch number of bare land did climb dramatically, but single patch area increased. The research demonstrated that desert and Saline soils patches were activated by the human behavior and climate change. The information from the ETM+ and Aster images was proved be an effective and efficient way to be applied in regional environmental managements.

Proterozoic polymetamorphism in the Quanji Block, northwestern China: Evidence from microtextures, garnet compositions and monazite CHIME ages

NASA Astrophysics Data System (ADS)

Wang, Qinyan; Pan, Yuanming; Chen, Nengsong; Li, Xiaoyan; Chen, Haihong

2009-05-01

The Quanji Block, situated close to the triple junction of three major Precambrian terranes in China (i.e., the North China Craton, the Yangtze Block and the Tarim Block), is composed of Precambrian metamorphic crystalline basement and an unmetamorphosed Mesozoic-Paleozoic sedimentary cover; it has been interpreted as a remnant continental fragment. Microtextural relationships, garnet trace element compositions, and monazite CHIME ages in paragneisses, schists and granitic leucosomes show two episodes of regional metamorphism in the Quanji Block basement. The first regional metamorphism and accompaning anatexis took place at ˜1.93 Ga; the second regional metamorphism occurred between ˜1.75 and ˜1.71 Ga. Mineral compositions of the first metamorphism, including those of monazite, were significantly disturbed by the second event. These two regional metamorphic episodes were most likely linked to assembly and breakup of the supercontinent Columbia, respectively.

Contamination by persistent toxic substances in surface sediment of urban rivers in Chaohu City, China.

PubMed

Li, Feipeng; Zhang, Haiping; Meng, Xiangzhou; Chen, Ling; Yin, Daqiang

2012-01-01

The concentration and spatial distribution of persistent toxic substances (PTS) in the river sediment in Chaohu City, China were investigated. A total of nine surface sediments were collected and the selected PTS pollutants including six heavy metals and nineteen polybrominated diphenyl ethers (PBDEs) were analyzed. The mean heavy metal concentrations (in mg/kg, dry weight) ranged within 0.18-1.53 (Hg), 50.08-200.18 (Cu), 118.70-313.65 (Zn), 50.77-310.85 (Cr), 37.12-92.72 (Pb) and 13.29-197.24 (As), and Cu, Zn and As have been regarded as the main metal pollutants. The levels of PBDEs (1.2-12.1 ng/g) and BDE-209 (2.4-30.5 ng/g) were at the middle level of the global range. BDE-209 was the predominant congener (67.0%-85.7%), which agrees with the fact that technical deca-BDE mixtures are the dominant PBDE formulation in China. The relative high level of PTS pollutants in the western part of the city is probably owing to the intensive agricultural activities and lack of sewerage system there. The ecological risk assessment with the sediment quality guidelines (SOGs) indicates that the urban river sediments in the city have been heavily contaminated by heavy metals with probable ecotoxicological impacts on freshwater organisms and the main toxic pollutants are Hg and As. The results of current study imply that the city, and perhaps many other small cities in China as well, requires immediate pollution control measures with emphasis on not only conventional organic pollutants but also on PTS such as heavy metals and PBDEs.

Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China.

PubMed

Mai, Bi-Xian; Fu, Jia-Mo; Sheng, Guo-Ying; Kang, Yue-Hui; Lin, Zheng; Zhang, Gan; Min, Yu-Shuan; Zeng, Eddy Y

2002-01-01

Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng/g, dry weight, while those of PCBs range from 11 to 486 ng/g. The CPs concentrations of the estuarine sediment samples are in the range 6-1658 ng/g, while concentrations of PCBs are in the range 10-339 ng/g. Total PAH concentration ranges from 1168 to 21,329 ng/g in the riverine sediment samples, whereas the PAH concentration ranges from 323 to 14,812 ng/g in the sediment samples of the Estuary. Sediment samples of the Zhujiang River and Macao harbor around the Estuary show the highest concentrations of CPs, PCBs, and PAHs. Possible factors affecting the distribution patterns are also discussed based on the usage history of the chemicals, hydrologic condition, and land erosion due to urbanization processes. The composition of PAHs is investigated and used to assess petrogenic, combustion and naturally derived PAHs of the sediment samples of the Pearl River Delta. In addition, the concentrations of a number of organic compounds of the Pearl River Delta samples indicate that sediments of the Zhujiang river and Macao harbor are most likely to pose biological impairment.

Total, chemical, and biological oxygen consumption of the sediments in the Ziya River watershed, China.

PubMed

Rong, Nan; Shan, Baoqing

2016-07-01

Sediment oxygen demand (SOD) is a critical dissolved oxygen (DO) sink in many rivers. Understanding the relative contributions of the biological and chemical components of SOD would improve our knowledge of the potential environmental harm SOD could cause and allow appropriate management systems to be developed. A various inhibitors addition technique was conducted to measure the total, chemical, and biological SOD of sediment samples from 13 sites in the Ziya River watershed, a severely polluted and anoxic river system in the north of China. The results showed that the major component of SOD was chemical SOD due to iron predominate. The ferrous SOD accounted for 21.6-78.9 % of the total SOD and 33.26-96.79 % of the chemical SOD. Biological SOD represented 41.13 % of the overall SOD averagely. Sulfide SOD accounted for 1.78-45.71 % of the total SOD and it was the secondary predominate of the chemical SOD. Manganous SOD accounted for 1.2-16.6 % of the total SOD and it was insignificant at many sites. Only four kinds of benthos were collected in the Ziya River watershed, resulting from the low DO concentration in the sediment surface due to SOD. This study would be helpful for understanding and preventing the potential sediment oxygen depletion during river restoration.

Quantitative tolerance values for common stream benthic macroinvertebrates in the Yangtze River Delta, Eastern China.

PubMed

Qin, Chun-Yan; Zhou, Jin; Cao, Yong; Zhang, Yong; Hughes, Robert M; Wang, Bei-Xin

2014-09-01

Aquatic organisms' tolerance to water pollution is widely used to monitor and assess freshwater ecosystem health. Tolerance values (TVs) estimated based on statistical analyses of species-environment relationships are more objective than those assigned by expert opinion. Region-specific TVs are the basis for developing accurate bioassessment metrics particularly in developing countries, where both aquatic biota and their responses to human disturbances have been poorly documented. We used principal component analysis to derive a synthetic gradient for four stressor variables (total nitrogen, total phosphorus, dissolved oxygen, and % silt) based on 286 sampling sites in the Taihu Lake and Qiantang River basins (Yangtze River Delta), China. We used the scores of taxa on the first principal component (PC1), which explained 49.8% of the variance, to estimate the tolerance values (TV(r)) of 163 macroinvertebrates taxa that were collected from at least 20 sites, 81 of which were not included in the Hilsenhoff TV lists (TV(h)) of 1987. All estimates were scaled into the range of 1-10 as in TV(h). Of all the taxa with different TVs, 46.3% of TV(r) were lower and 52.4% were higher than TV(h). TV(r) were significantly (p < 0.01, Fig. 2), but weakly (r(2) = 0.34), correlated with TVh. Seven biotic metrics based on TVr were more strongly correlated with the main stressors and were more effective at discriminating references sites from impacted sites than those based on TV(h). Our results highlight the importance of developing region-specific TVs for macroinvertebrate-based bioassessment and to facilitate assessment of streams in China, particularly in the Yangtze River Delta.

A new strain of Crimean-Congo hemorrhagic fever virus isolated from Xinjiang, China.

PubMed

Guo, Rong; Shen, Shu; Zhang, Yanfang; Shi, Junming; Su, Zhengyuan; Liu, Dan; Liu, Jinliang; Yang, Juan; Wang, Qiguo; Hu, Zhihong; Zhang, Yujiang; Deng, Fei

2017-02-01

Crimean-Congo hemorrhagic fever virus (CCHFV) is a highly pathogenic tick-borne virus with a fatality rate of up to 50% in humans. CCHFV is widely distributed in countries around the world. Outbreaks of CCHFV infection in humans have occurred in prior years in Xinjiang Province, China. Epidemiological surveys have detected CCHFV RNA in ticks and animals; however, few isolates were identified. In this study, we identified and isolated a new CCHFV strain from Hyalomma asiaticum asiaticum ticks collected from north of Tarim Basin in Xinjiang, China. A preliminary investigation of infection and antigens expression of CCHFV was performed in newborn mice. The target tissues for CCHFV replication in newborn mice were identified. The analysis of the phylogenetic relationships with other Chinese strains suggested that diverse genotypes of CCHFV have circulated in Xinjiang for years. These findings provide important insights into our understanding of CCHFV infection and evolution as well as disease prevention and control for local residents.

Distributions, Early Diagenesis, and Spatial Characteristics of Amino Acids in Sediments of Multi-Polluted Rivers: A Case Study in the Haihe River Basin, China.

PubMed

Zhao, Yu; Shan, Baoqing; Tang, Wenzhong; Zhang, Hong; Rong, Nan; Ding, Yuekui

2016-02-19

The Haihe River Basin, which is one of the most water-scarce and polluted river basins in China, has abnormally high nitrogen levels. In this study, total hydrolyzable amino acids (THAAs) were measured in surface sediment and sediment core samples in the Haihe River Basin to determine if amino acids were potential sources of ammonium, organic nitrogen, and organic carbon. The rivers were found to be in a state of hypoxia and contain abnormally high levels of ammonium and organic nitrogen. Additionally, NH₃-N was the predominant form of inorganic nitrogen in the surface sediments, while organic nitrogen accounted for 92.53% of sedimentary nitrogen. THAAs-C accounted for 14.92% of the total organic carbon, while THAAs-N accounted for more than 49.59% of organic nitrogen and 45.68% of total nitrogen. The major fraction of THAAs were protein amino acids. Three sediment cores of the most heavily polluted rivers also showed high levels of THAAs. Evaluation of the degradation index (DI) of sedimentary organic matter in sediments evaluated based on the THAAs revealed that most positive DI values were found in the downstream portion of the Ziya River Watershed. Additionally, the DI of surface sediment was correlated with THAAs (r² = 0.763, p < 0.001), as was the DI of sediment cores (r² = 0.773, p < 0.001). Overall, amino acids in sediments were found to be an important potential source of ammonium, organic nitrogen, and organic carbon.

Distributions, Early Diagenesis, and Spatial Characteristics of Amino Acids in Sediments of Multi-Polluted Rivers: A Case Study in the Haihe River Basin, China

PubMed Central

Zhao, Yu; Shan, Baoqing; Tang, Wenzhong; Zhang, Hong; Rong, Nan; Ding, Yuekui

2016-01-01

The Haihe River Basin, which is one of the most water-scarce and polluted river basins in China, has abnormally high nitrogen levels. In this study, total hydrolyzable amino acids (THAAs) were measured in surface sediment and sediment core samples in the Haihe River Basin to determine if amino acids were potential sources of ammonium, organic nitrogen, and organic carbon. The rivers were found to be in a state of hypoxia and contain abnormally high levels of ammonium and organic nitrogen. Additionally, NH3-N was the predominant form of inorganic nitrogen in the surface sediments, while organic nitrogen accounted for 92.53% of sedimentary nitrogen. THAAs-C accounted for 14.92% of the total organic carbon, while THAAs-N accounted for more than 49.59% of organic nitrogen and 45.68% of total nitrogen. The major fraction of THAAs were protein amino acids. Three sediment cores of the most heavily polluted rivers also showed high levels of THAAs. Evaluation of the degradation index (DI) of sedimentary organic matter in sediments evaluated based on the THAAs revealed that most positive DI values were found in the downstream portion of the Ziya River Watershed. Additionally, the DI of surface sediment was correlated with THAAs (r2 = 0.763, p < 0.001), as was the DI of sediment cores (r2 = 0.773, p < 0.001). Overall, amino acids in sediments were found to be an important potential source of ammonium, organic nitrogen, and organic carbon. PMID:26907310

Regional variations of organophosphorus flame retardants - Fingerprint of large river basin estuaries/deltas in Europe compared with China.

PubMed

Wolschke, Hendrik; Sühring, Roxana; Massei, Riccardo; Tang, Jianhui; Ebinghaus, Ralf

2018-05-01

This study reports the occurrence and distribution of organophosphorus flame retardants and plasticizer (OPEs) in sediments of eight large river basin estuaries and deltas across Europe. A robust and sensitive OPE analysis method was developed through the application of an in-cell clean-up in an accelerated solvent extraction and the use of an GC-MSMS System for instrumental analyses. OPEs were detected in all sediment samples with sum concentrations of up to 181 ng g -1 dw. A fingerprinting method was used to identify river specific pattern to compare river systems. The estuaries and deltas were chosen to have a conglomerate print of the whole river. The results are showing very similar OPE patterns across Europe with minor differences driven by local industrial input. The European estuary concentrations and patterns were compared with OPEs detected in the Xiaoquing River in China, as an example for a region with other production, usage and legislative regulations. The Chinese fingerprint differed significant from the overall European pattern. Copyright © 2018 Elsevier Ltd. All rights reserved.

Economic compensation standard for irrigation processes to safeguard environmental flows in the Yellow River Estuary, China

NASA Astrophysics Data System (ADS)

Pang, Aiping; Sun, Tao; Yang, Zhifeng

2013-03-01

SummaryAgriculture and ecosystems are increasingly competing for water. We propose an approach to assess the economic compensation standard required to release water from agricultural use to ecosystems while taking into account seasonal variability in river flow. First, we defined agricultural water shortage as the difference in water volume between agricultural demands and actual supply after maintaining environmental flows for ecosystems. Second, we developed a production loss model to establish the relationship between production losses and agricultural water shortages in view of seasonal variation in river discharge. Finally, we estimated the appropriate economic compensation for different irrigation stakeholders based on crop prices and production losses. A case study in the Yellow River Estuary, China, demonstrated that relatively stable economic compensation for irrigation processes can be defined based on the developed model, taking into account seasonal variations in river discharge and different levels of environmental flow. Annual economic compensation is not directly related to annual water shortage because of the temporal variability in river flow rate and environmental flow. Crops that have stable planting areas to guarantee food security should be selected as indicator crops in economic compensation assessments in the important grain production zone. Economic compensation may be implemented by creating funds to update water-saving measures in agricultural facilities.

Systematic impact assessment on inter-basin water transfer projects of the Hanjiang River Basin in China

NASA Astrophysics Data System (ADS)

Zhou, Yanlai; Guo, Shenglian; Hong, Xingjun; Chang, Fi-John

2017-10-01

China's inter-basin water transfer projects have gained increasing attention in recent years. This study proposes an intelligent water allocation methodology for establishing optimal inter-basin water allocation schemes and assessing the impacts of water transfer projects on water-demanding sectors in the Hanjiang River Basin of China. We first analyze water demands for water allocation purpose, and then search optimal water allocation strategies for maximizing the water supply to water-demanding sectors and mitigating the negative impacts by using the Standard Genetic Algorithm (SGA) and Adaptive Genetic Algorithm (AGA), respectively. Lastly, the performance indexes of the water supply system are evaluated under different scenarios of inter-basin water transfer projects. The results indicate that: the AGA with adaptive crossover and mutation operators could increase the average annual water transfer from the Hanjiang River by 0.79 billion m3 (8.8%), the average annual water transfer from the Changjiang River by 0.18 billion m3 (6.5%), and the average annual hydropower generation by 0.49 billion kW h (5.4%) as well as reduce the average annual unmet water demand by 0.40 billion m3 (9.7%), as compared with the those of the SGA. We demonstrate that the proposed intelligent water allocation schemes can significantly mitigate the negative impacts of inter-basin water transfer projects on the reliability, vulnerability and resilience of water supply to the demanding sectors in water-supplying basins. This study has a direct bearing on more intelligent and effectual water allocation management under various scenarios of inter-basin water transfer projects.

Distribution and sources of the polycyclic aromatic hydrocarbons in the sediments of the Pearl River estuary, China.

PubMed

Zhang, Jian-Dong; Wang, You-Shao; Cheng, Hao; Jiang, Zhao-Yu; Sun, Cui-Ci; Wu, Mei-Lin

2015-10-01

The Pearl River delta, one of the most prosperous economically region in China, has experienced significant contaminant inputs. However, the dynamics of pollutants in the Pearl River estuary and the adjacent coastal areas are still unclear at present. In the paper, distribution and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments of the Pearl River estuary. The total PAHs concentrations ranged from 126.08 to 3828.58 ng/g with a mean value of 563.52 ng/g, whereas the highest PAHs were observed in Guangzhou channel. Among the U.S. Environmental Protection Agency's 16 priority PAHs, PAHs with 3-4 rings exhibited relative higher levels. A positive relationship was found between PAHs and total organic carbon. The source analysis further showed that the major sources of PAHs in the Pearl River estuary were originated from the pyrolytic inputs, reflecting a mixed energy structure such as wood, coal and petroleum combustion. In summary, although PAHs in Lingding Bay and the adjacent coastal areas of the Pearl River estuary exhibited a relatively low pollution level, the relatively high pollution level of PAHs in Guangzhou channel will be attended.

Dissolved trace elements in a nitrogen-polluted river near to the Liaodong Bay in Northeast China.

PubMed

Bu, Hongmei; Song, Xianfang; Guo, Fen

2017-01-15

Dissolved trace element concentrations (Ba, Fe, Mn, Si, Sr, and Zn) were investigated in the Haicheng River near to the Liaodong Bay in Northeast China during 2010. Dissolved Ba, Fe, Mn, and Sr showed significant spatial variation, whereas dissolved Fe, Mn, and Zn displayed seasonal variations. Conditions such as water temperature, pH, and dissolved oxygen were found to have an important impact on redox reactions involving dissolved Ba, Fe, and Zn. Dissolved Fe and Mn concentrations were regulated by adsorption or desorption of Fe/Mn oxyhydroxides and the effects of organic carbon complexation on dissolved Ba and Sr were found to be significant. The sources of dissolved trace elements were found to be mainly from domestic sewage, industrial waste, agricultural surface runoff, and natural origin, with estimated seasonal and annual river fluxes established as important inputs of dissolved trace elements from the Haicheng River into the Liaodong Bay or Bohai Sea. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydroclimate-driven changes in the landscape structure of the terminal lakes and wetlands of the China's Heihe River Basin.

PubMed

Xiao, Shengchun; Xiao, Honglang; Peng, Xiaomei; Song, Xiang

2015-01-01

Changes in the landscape structure of terminal lakes and wetlands along inland rivers in arid areas are determined by the water balance in the river basins under the impacts of climate change and human activities. Studying the evolution of these landscapes and the mechanisms driving these changes is critical to the sustainable development of river basins. The terminal lakes and wetlands along the lower reaches of the Heihe River, an inland river in arid northwestern China, can be grouped into three types: runoff-recharged, groundwater-recharged, and precipitation-recharged. These water-recharge characteristics determine the degree to which the landscape structure of a terminal lake or wetland is impacted by climate change and human activities. An analysis of seven remote-sensing and hydroclimatic data sets for the Heihe River basin during the last 50 years indicates that hydrological changes in the basin caused by regional human activities were the primary drivers of the observed changes in the spatial and temporal landscape-structure patterns of the terminal lakes and wetlands of the Heihe River. In this warm, dry climatic context, the lakes and wetlands gradually evolved toward and maintained a landscape dominated by saline-alkaline lands and grasslands.

Magnetic signature of river sediments drained into the southern and eastern part of the South China Sea (Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan)

NASA Astrophysics Data System (ADS)

Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

2017-01-01

Magnetic properties of 22 river samples collected in the Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan have been investigated in order to magnetically characterize the sediments drained and deposited into the South China Sea. The geological formations as well as the present climatic conditions are different from one region to another. Laboratory analyses include low-field magnetic susceptibility, anhysteretic (ARM) and isothermal (IRM) remanent magnetizations acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis cycles and low-temperature magnetic measurements. The magnetic properties indicate that the sediments are a mixture of hematite, magnetite and pyrrhotite in different proportions depending on the region. Combined with results previously reported for the three main Asian rivers (Pearl, Red and Mekong rivers), the new data indicate that, in general, hematite-rich sediments are delivered to the southern basin of the South China Sea while the northern basin is fed with magnetite and pyrrhotite-rich sediments. In addition to this general picture, some variability is observed at smaller geographic scales. Indeed, the magnetic assemblages are closely related to the geology of the various catchments while clay minerals, previously reported for the same samples, are more representative of the climatic conditions under which the parent rocks have evolved within each catchment. The magnetic fraction, now well characterized in the main river sediments drained into the South China Sea, can be used as a tracer for changes in precipitation on land and in oceanic water mass transport and exchange.

Hydrological effects of cropland and climatic changes in arid and semi-arid river basins: A case study from the Yellow River basin, China

NASA Astrophysics Data System (ADS)

Li, Huazhen; Zhang, Qiang; Singh, Vijay P.; Shi, Peijun; Sun, Peng

2017-06-01

The Yellow River basin is a typical semi-arid river basin in northern China. Serious water shortages have negative impacts on regional socioeconomic development. Recent years have witnessed changes in streamflow processes due to increasing human activities, such as agricultural activities and construction of dams and water reservoirs, and climatic changes, e.g. precipitation and temperature. This study attempts to investigate factors potentially driving changes in different streamflow components defined by different quantiles. The data used were daily streamflow data for the 1959-2005 period from 5 hydrological stations, daily precipitation and temperature data from 77 meteorological stations and data pertaining to cropland and large reservoirs. Results indicate a general decrease in streamflow across the Yellow River basin. Moreover significant decreasing streamflow has been observed in the middle and lower Yellow River basin with change points during the mid-1980s till the mid-1990s. The changes of cropland affect the streamflow components and also the cumulative effects on streamflow variations. Recent years have witnessed moderate cropland variations which result in moderate streamflow changes. Further, precipitation also plays a critical role in changes of streamflow components and human activities, i.e. cropland changes, temperature changes and building of water reservoirs, tend to have increasing impacts on hydrological processes across the Yellow River basin. This study provides a theoretical framework for the study of the hydrological effects of human activities and climatic changes on basins over the globe.

Characterization of CDOM of river waters in China using fluorescence excitation-emission matrix and regional integration techniques

NASA Astrophysics Data System (ADS)

Zhao, Ying; Song, Kaishan; Shang, Yingxin; Shao, Tiantian; Wen, Zhidan; Lv, Lili

2017-08-01

The spatial characteristics of fluorescent dissolved organic matter (FDOM) components in river waters in China were first examined by excitation-emission matrix spectra and fluorescence regional integration (FRI) with the data collected during September to November between 2013 and 2015. One tyrosine-like (R1), one tryptophan-like (R2), one fulvic-like (R3), one microbial protein-like (R4), and one humic-like (R5) components have been identified by FRI method. Principal component analysis (PCA) was conducted to assess variations in the five FDOM components (FRί (ί = 1, 2, 3, 4, and 5)) and the humification index for all 194 river water samples. The average fluorescence intensities of the five fluorescent components and the total fluorescence intensities FSUM differed under spatial variation among the seven major river basins (Songhua, Liao, Hai, Yellow and Huai, Yangtze, Pearl, and Inflow Rivers) in China. When all the river water samples were pooled together, the fulvic-like FR3 and the humic-like FR5 showed a strong positive linear relationship (R2 = 0.90, n = 194), indicating that the two allochthonous FDOM components R3 and R5 may originate from similar sources. There is a moderate strong positive correlation between the tryptophan-like FR2 and the microbial protein-like FR4 (R2 = 0.71, n = 194), suggesting that parts of two autochthonous FDOM components R2 and R4 are likely from some common sources. However, the total allochthonous substance FR(3+5) and the total autochthonous substances FR(1+2+4) exhibited a weak correlation (R2 = 0.40, n = 194). Significant positive linear relationships between FR3 (R2 = 0.69, n = 194), FR5 (R2 = 0.79, n = 194), and chromophoric DOM (CDOM) absorption coefficient a(254) were observed, which demonstrated that the CDOM absorption was dominated by the allochthonous FDOM components R3 and R5.

Prediction of dissolved oxygen concentration in hypoxic river systems using support vector machine: a case study of Wen-Rui Tang River, China.

PubMed

Ji, Xiaoliang; Shang, Xu; Dahlgren, Randy A; Zhang, Minghua

2017-07-01

Accurate quantification of dissolved oxygen (DO) is critically important for managing water resources and controlling pollution. Artificial intelligence (AI) models have been successfully applied for modeling DO content in aquatic ecosystems with limited data. However, the efficacy of these AI models in predicting DO levels in the hypoxic river systems having multiple pollution sources and complicated pollutants behaviors is unclear. Given this dilemma, we developed a promising AI model, known as support vector machine (SVM), to predict the DO concentration in a hypoxic river in southeastern China. Four different calibration models, specifically, multiple linear regression, back propagation neural network, general regression neural network, and SVM, were established, and their prediction accuracy was systemically investigated and compared. A total of 11 hydro-chemical variables were used as model inputs. These variables were measured bimonthly at eight sampling sites along the rural-suburban-urban portion of Wen-Rui Tang River from 2004 to 2008. The performances of the established models were assessed through the mean square error (MSE), determination coefficient (R 2 ), and Nash-Sutcliffe (NS) model efficiency. The results indicated that the SVM model was superior to other models in predicting DO concentration in Wen-Rui Tang River. For SVM, the MSE, R 2 , and NS values for the testing subset were 0.9416 mg/L, 0.8646, and 0.8763, respectively. Sensitivity analysis showed that ammonium-nitrogen was the most significant input variable of the proposal SVM model. Overall, these results demonstrated that the proposed SVM model can efficiently predict water quality, especially for highly impaired and hypoxic river systems.

Changes in nutrient ratios and phytoplankton community structure caused by hydropower development in the Maotiao River, China.

PubMed

Wang, Fushun; Wang, Baoli; Liu, Cong-Qiang; Liu, Xiaolong; Gao, Yang; Zhang, Jing; Li, Shuang

2014-06-01

Reservoirs created for hydropower production have become an important feature impacting a river. Understanding the effects of river impoundment on the downstream environment is critical to decision-making for water resource protection. The changes caused by impoundment are changes in water quality and the resulting effect on the phytoplankton community structure. The impacts caused by a series of reservoirs along a river are still not well understood. In this study, we conducted an investigation of five reservoirs along the Maotiao River, China. We found that a series of impoundments plays a role in decreasing the phytoplankton biomass in downstream reservoirs. Within the studied area, nitrogen is not a limiting factor for phytoplankton growth. The ratio of silicon to phosphorus (Si:P) can become a major factor in the regulation of phytoplankton community structure. The Si:P ratio increased from upstream to downstream reservoirs, causing a concurrent increase in the percentage of Bacillariophyta, particularly during the winter. In addition, our results indicate that the creation of dams eliminates Si limitation downstream.

Control factors and scale analysis of annual river water, sediments and carbon transport in China.

PubMed

Song, Chunlin; Wang, Genxu; Sun, Xiangyang; Chang, Ruiying; Mao, Tianxu

2016-05-11

Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

Distribution and Risk Assessment of Antibiotics in a Typical River in North China Plain.

PubMed

Li, Qingzhao; Gao, Junxia; Zhang, Qiuling; Liang, Lizhen; Tao, He

2017-04-01

We evaluated the occurrence and distribution of 12 antibiotics from the sulfonamide (SAs), fluoroquinolone (FQs) and tetracycline (TCs) groups in the Weihe River, North China. The total antibiotic concentrations in surface water, pore water, and sediment samples ranged from 11.1 to 173.1 ng/L, 5.8 to 103.9 ng/L, and 9.5 to 153.4 μg/kg, respectively. The values of the sediment-water partitioning coefficient in the Weihe River varied widely, from not detected to 943, 2213, and 2405 L/kg for SAs, FQs, and TCs, respectively. The values of the partitioning coefficients between sediment and surface water were generally lower than those between sediment and pore water, which indicated ongoing inputs to the water. The risk assessment showed that there were relatively high ecological risks to aquatic algae in this area from sulfamethoxazole, norfloxacin, tetracycline, ofloxacin, and ciprofloxacin.

Optimization of wetland restoration siting and zoning in flood retention areas of river basins in China: A case study in Mengwa, Huaihe River Basin

NASA Astrophysics Data System (ADS)

Zhang, Xiaolei; Song, Yuqin

2014-11-01

Wetland restoration in floodplains is an ecological solution that can address basin-wide flooding issues and minimize flooding and damages to riverine and downstream areas. High population densities, large economic outputs, and heavy reliance on water resources make flood retention and management pressing issues in China. To balance flood control and sustainable development economically, socially, and politically, flood retention areas have been established to increase watershed flood storage capacities and enhance the public welfare for the populace living in the areas. However, conflicts between flood storage functions and human habitation appear irreconcilable. We developed a site-specific methodology for identifying potential sites and functional zones for wetland restoration in a flood retention area in middle and eastern China, optimizing the spatial distribution and functional zones to maximize flood control and human and regional development. This methodology was applied to Mengwa, one of 21 flood retention areas in China's Huaihe River Basin, using nine scenarios that reflected different flood, climatic, and hydraulic conditions. The results demonstrated improved flood retention and ecological functions, as well as increased economic benefits.

Spatio-temporal variability of periphytic protozoa related to environment in the Niyang River, Tibet, China

NASA Astrophysics Data System (ADS)

Liu, Haiping; Ye, Shaowen; Yang, Xuefeng; Guo, Chuanbo; Zhang, Huijuan; Fan, Liqing; Zhang, Liangsong; Sovan, Lek; Li, Zhongjie

2017-05-01

The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau river ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and river ecology. In this study, the composition, abundance, and diversity of periphytic protozoa were investigated across four seasons from 2008 to 2009 to better understand their spatio-temporal patterns and relationship to the environment. Our investigation shows that periphytic protozoa in the Niyang River contained 15 genera, belonged to Tubulinea, Alveolata, Discosea and Rhizaria, Alveolata possessed most genera, up to nine, with highest share in abundance, exceeding 50%, Difflugia and Glaucoma were dominant genera. Moreover, four diversity indices of periphytic protozoa, including species richness, total abundance, Shannon-Wiener diversity index and Pielou's evenness index, displayed a significant descending trend as the seasons continued, in the order of winter, spring, summer and autumn; with a significant difference existing between winter and summer (or autumn) for Shannon-Wiener diversity index and species richness ( P<0.05). Four of these diversity indices also presented a V-shaped pattern between the upper middle course of the Niyang River and the confluence of the Niyang River and Yarlung Zangbo River, with the lowest value occurred in the middle course of the Niyang River. However, no significant variation was found through the Niyang River ( P>0.05). In addition, canonical correlation analysis (CCA) shows that the densities of Difflugia, Glaucomais, Enchelydium, Cyphoderia, and Enchelys correlate with water temperature, alkalinity, hardness, pH, and dissolved oxygen, respectively. Lastly, the relationship between periphytic protozoa diversity and the environmental factors of the Niyang River can be predicted using classification and regression trees (CART) annalysis, which suggests that the total abundance and Shannon-Wiener diversity index would be

[Influence of land use change on dissolved organic carbon export in Naoli River watershed. Northeast China].

PubMed

Yin, Xiao-min; Lyu, Xian-guo; Liu, Xing-tu; Xue, Zhen-shan

2015-12-01

The present study was conducted to evaluate the influence of land use change on dissolved organic carbon (DOC) export in Naoli River watershed, Northeast China. Seasonal variation of DOC concentrations of the river water and its relationship with land use in the whole watershed and 100 m riparian zone at the annual average scale were analyzed using the method of field sampling, laboratory analysis, GIS and statistics analysis. The results showed that the concentrations of DOC under base flow conditions in spring and summer were significantly higher than that in fall in the study watershed. The seasonal trend of DOC concentrations in wetland-watersheds was similar to that in all the sub-watersheds, while significantly different from that in non-wetland watersheds. On the annual average scale, percentage of wetland in the whole watershed and paddy field in the 100 m riparian zone had positive relationship with the DOC concentration in the river water, while percentage of forest in the whole watershed had negative relationship with it (P < 0.05). It indicated that wetland in the sub-watershed played a significant role in the seasonal variation of DOC in river water of Naoli River watershed. Wetland in the watershed and paddy field in the 100 m riparian zone significantly promoted DOC export, while forest alleviated it. Land use change in the watershed in the past few decades dramatically changed the DOC balance of river water.

Water-ecosystem-economy nexus under human intervention and climate change: a study in the Heihe River Basin (China)

NASA Astrophysics Data System (ADS)

Zheng, Y.; Tian, Y.; Wu, X.; Feng, D.

2017-12-01

Recently, "One Belt and One Road" initiative, namely, building the "Silk Road Economic Belt" and "21st Century Maritime Silk Road", has become a global strategy of China and has been discussed as China's "Marshall Plan". The overland route of "One Belt" comes across vast arid lands, where the local population and ecosystem compete keenly for limited water resources. Water and environmental securities represent an important constraint of the "One Belt" development, and therefore understanding the complex water-ecosystem-economy nexus in the arid inland areas is very important. One typical case is Heihe River Basin (HRB), the second largest inland river basin of China, where the croplands in its middle part sucked up the river flow and groundwater, causing serious ecological problems in its lower part (Gobi Desert). We have developed an integrated hydrological-ecological model for the middle and lower HRB (the modeling domain has an area of 90,589 km2), which served as a platform to fuse multi-source data and provided a coherent understanding on the regional water cycle. With this physically based model, we quantitatively investigated how the nexus would be impacted by human intervention, mainly the existing and potential water regulations, and what would be the uncertainty of the nexus under the climate change. In studying the impact of human intervention, simulation-optimization analyses based on surrogate modeling were performed. In studying the uncertainty resulted from the climate change, outputs of multiple GCMs were downscaled for this river basin to drive ecohydrological simulations. Our studies have demonstrated the significant tradeoffs among the crop production in the middle HRB, the water and environmental securities of the middle HRB, and the ecological health of the lower HRB. The underlying mechanisms of the tradeoffs were also systematically addressed. The climate change would cause notable uncertainty of the nexus, which makes the water resources

Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in surface water from Liaohe River Basin, northeast China.

PubMed

Lv, Jiapei; Xu, Jian; Guo, Changsheng; Zhang, Yuan; Bai, Yangwei; Meng, Wei

2014-01-01

Liaohe River Basin is an important region in northeast China, which consists of several main rivers including Liao River, Taizi river, Daliao River, and Hun River. As a highly industrialized region, the basin receives dense waste discharges, causing severe environmental problems. In this study, the spatial and temporal distribution of aqueous polycyclic aromatic hydrocarbons (PAHs) in Liaohe River Basin from 50 sampling sites in both dry (May) and level (October) periods in 2012 was investigated. Sixteen USEPA priority PAHs were quantified by gas chromatography/mass selective detector. The total PAH concentration ranged from 111.8 to 2,931.6 ng/L in the dry period and from 94.8 to 2766.0 ng/L in the level period, respectively. As for the spatial distribution, the mean concentration of PAHs followed the order of Taizi River > Daliao River > Hun River > Liao River, showing higher concentrations close to large cities with dense industries. The composition and possible sources of PAHs in the water samples were also determined. The fractions of low molecular weight PAHs ranged from 58.2 to 93.3 %, indicating the influence of low or moderate temperature combustion process. Diagnostic ratios, principal component analysis, and hierarchical cluster analysis were used to study the possible source categories in the study area, and consistent results were obtained from different techniques, that PAHs in water samples mainly originated from complex sources, i.e., both pyrogenic and petrogenic sources. The benzo[a]pyrene equivalents (EBaP) characterizing the ecological risk of PAHs to the aquatic environment suggested that PAHs in Liaohe River Basin had already caused environmental health risks.

The distribution of antibiotics in water of a river basin in South China

NASA Astrophysics Data System (ADS)

Meng, T.; Cheng, W.; Wang, M.; Wan, T.; Cheng, M.; Zhang, C. C.; Jia, Z. Y.

2017-08-01

In water environment field, one of the most attractive research topics is the determination of contamination characteristics of antibiotics in water. In order to investigate the distribution of antibiotics in surface water and drinking water of a certain river basin in southern China, we determined the types and concentrations of antibiotics that contaminated the river by performing HPLC-ESI-MS/MS method. Thus, we detected 17 antibiotics in four surface water samples (B1, B2, B3, and B4). In sampling points B3 and B4, we detected 16 antibiotics separately. The detection rates of norfloxacin, ofloxacin, and erythromycin-H2O were 100%, and the antibiotic erythromycin-H2O had the maximum concentration. In six drinking water samples (A1, A2, A3, A4, A5, and A6), we detected 13 antibiotics. In A5 water samples, we detected all the 13 antibiotics. The detection rate of ofloxacin and erythromycin-H2O was 100%, and erythromycin-H2O was the antibiotic with the highest concentration. We also found that from the upstream to the downstream of the river basin, the types of antibiotics in river increased gradually. In the upstream water samples (B1), we detected three antibiotics. Erythromycin-H2O was the antibiotic with the highest concentration of 6.61 ng/L, and sulfapyridine had the lowest concentration of 2.82 ng/L. In the downstream water samples (B4), we detected 16 antibiotics. Erythromycin-H2O was the antibiotic with the highest concentration of 277.58 ng/L, and the Sulfamonomethoxine was the antibiotic with the second-highest concentration of 242.1 ng/L. In addition, different membrane treatment processes could remove different amounts of antibiotics from the water samples. The study is an important reference for providing environmental protection to river water basin.

Sediment heavy metals and benthic diversities in Hun-Tai River, northeast of China.

PubMed

Qu, Xiaodong; Ren, Ze; Zhang, Min; Liu, Xiaobo; Peng, Wenqi

2017-04-01

In aquatic ecosystems, metal contamination in sediments has become a ubiquitous environmental problem, causing serious issues. Hun-Tai River, located in northeast of China, flows through an important heavy industry region and metropolitan area. This study examined the heavy metals (Cd, Cr, Cu, Fe, Mn, Pb, Ni, and Zn) of sediments and diversities (taxa richness, Shannon diversity, and evenness) of benthic assemblages (benthic algae and macroinvertebrate) in Hun-Tai River. The results clearly described the spatial patterns of metal contamination in terms of geo-accumulation index and contamination factor, as well as the spatial patterns of benthic diversities in terms of taxa richness, Shannon index, and evenness by kriging interpolation. The sediments were largely contaminated by Cd, followed by Cu, Fe, Zn, Mn, and Ni. Cd and Zn had similar spatial patterns and similar sources. Cu, Fe, Mn, and Ni showed similar spatial patterns and similar sources. The surface sediments were unpolluted by Cr and Pb. The metal mines and the heavy industry in the major cities were the potential pollution sources. Benthic algae and macroinvertebrate responded similarly to the heterogeneous environment and metal contamination, with high taxa richness and Shannon index in middle-upper reaches of Hun-Tai River. Evenness showed complex spatial patterns. Under low contamination, both taxa richness, Shannon diversity, and evenness had a large variation range. However, under the moderate and high contamination, the taxa richness and Shannon diversity kept to a low level but the evenness had a high level. This study provided insights into the sediment heavy metal contamination in Hun-Tai River.

River water quality and pollution sources in the Pearl River Delta, China.

PubMed

Ouyang, Tingping; Zhu, Zhaoyu; Kuang, Yaoqiu

2005-07-01

Some physicochemical parameters were determined for thirty field water samples collected from different water channels in the Pearl River Delta Economic Zone river system. The analytical results were compared with the environmental quality standards for surface water. Using the SPSS software, statistical analyses were performed to determine the main pollutants of the river water. The main purpose of the present research is to investigate the river water quality and to determine the main pollutants and pollution sources. Furthermore, the research provides some approaches for protecting and improving river water quality. The results indicate that the predominant pollutants are ammonium, phosphorus, and organic compounds. The wastewater discharged from households in urban and rural areas, industrial facilities, and non-point sources from agricultural areas are the main sources of pollution in river water in the Pearl River Delta Economic Zone.

The development and adaption of early agriculture in Huanghe River Valley, China

NASA Astrophysics Data System (ADS)

Li, X.

2017-12-01

support that the likely route of wheat into China was via Russia and Mongolia. After 4000 cal BP, Eight crop types of foxtail millet, broomcorn millet, rice, wheat, barley, oats, soybean and buckwheat appeared together in Huanghe River valley, which suggest the earliest complexity agriculture in East Asia.

Assessment of heavy metals in sediment in a heavily polluted urban river in the Chaohu Basin, China

NASA Astrophysics Data System (ADS)

Shao, Shiguang; Xue, Lianqing; Liu, Cheng; Shang, Jingge; Wang, Zhaode; He, Xiang; Fan, Chengxin

2016-05-01

The Nanfei River (Anhui Province, China) is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution, the current pollution status, and spatial and temporal variations in heavy metal pollution in sediments. The concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in sediments ranged from 5.67-113, 0.08-40.2, 41.6-524, 15.5-460, 0.03-4.84, 13.5-180, 18.8-250, and 47.9-1 996 mg/kg, and the average concentrations of each metal were 1.7, 38.7, 1.8, 5.5, 18.8, 1.3, 2.5, and 11.1 times greater than the background values, respectively. Multivariate statistical analysis demonstrated that Hg, Cu, Cr, Cd, and Ni may have originated from industrial activities, whereas As and Pb came from agricultural activities. The fuzzy comprehensive assessment method, based on the fuzzy mathematics theory, was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed. The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers, but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sili and Banqiao Rivers. Therefore, sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status.

Satellite remote sensing of water resources in the Yangtze and Yellow Rivers of China based on infrared imagery of cloud distributions

NASA Technical Reports Server (NTRS)

Hung, R. J.; Dodge, James C.

1990-01-01

Although the two largest rivers in China originate in the same region, separated only by the Bayanhar Mountains as a watershed, the Yangtze and Yellow Rivers behave in quite different ways. Most of the warm and humid air currents from the Arabian Sea and Bay of Bengal are blocked by the Bayanhar Mountains. As a result, the amount of water in the Yellow River is only 5 percent of that in the Yangtze River. Based on the cloud coverage area and the cloud volumetric distributions, and also the thickness above 9.4 kms of the cumulus clouds located north and south of the Bayanhar Mountains, from GEO satellite IR imagery, the results suggest that a more detailed investigation is warranted in the hope that the proper modification of cumuli north of the Bayanhar Mountains would enhance the rainfall over the fountainhead of the Yellow River.

Multi-element study of sediments from the river Khai River - Nha Trang Bay estuarine system, South China Sea.

NASA Astrophysics Data System (ADS)

Koukina, Sofia; Lobus, Nikolai; Peresypkin, Valery; Baturin, Gleb; Smurov, Andrey

2013-04-01

Major (Al, Fe, Ti, Mg, Ca, Na, K), minor (Mn) and trace (Cr, Ni, Cd, V, Zn, Cu, Pb, Sb, Bi, Sn, Ag, Li, Co, As, Zr, Mo, Hg) elements along with nutrients (TOC, TS, TP) and TIC were first determined in ten surface sediment samples from the Khai River - Nha Trang Bay estuarine system, South China Sea. According to the sediment quality guidelines and reference background values, most of the element contents that were studied were below the threshold levels, while the content of Ag exceeded significantly the hazardous levels in the most of the samples along the river - sea transect. The local anthropogenic and/or environmental sources of Ag within the region need special study. Aluminum and lithium normalization indicated some specific features in the abundance and distribution of the elements along the salinity gradient. The mean grain size of the sediments decreased from the river part to the bay part of the transect. Sedimentary TOC was relatively low (1-2 %) and showed independent distribution along the river - sea transect in relation to the other elements that were studied. Ca, Ba and Sr distribution showed some sporadic enrichment and were largely controlled by the TIC content in sediments. Sedimentary TP, Al, Fe, Mn, Ti, Na, K, Li, Co, Cs, Zn and V varied within the narrow range and tended to increase seaward. These elements are most likely controlled by the accumulation of their fine grained aluminosilicate host minerals and materials at sites determined by hydrodynamic conditions, i. e., in the sea floor depression. TS, As, Sn, Bi, U, Cd and Mo were relatively low in the sediments studied and tended to decrease seaward with the slight elevation in the intermediate part of the transect. These elements can be scavenged by and/or co-precipitated with the dissolved and particulate materials of the river discharge and further deposited on the river - sea geochemical barrier in the course of estuarine sedimentation. The distribution of Ni, Cr, Zr Cu, Pb, Sb, Hg and

The biogeography of fungal communities in wetland sediments along the Changjiang River and other sites in China

PubMed Central

Wu, Bing; Tian, Jianqing; Bai, Chunming; Xiang, Meichun; Sun, Jingzu; Liu, Xingzhong

2013-01-01

Whether fungal community structure depends more on historical factors or on contemporary factors is controversial. This study used culture-dependent and -independent (polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)) methods to assess the influence of historical and contemporary factors on the distributions of fungi in the wetland sediments at 10 locations along the Changjiang River and at 10 other locations in China. The culture-dependent approach detected greater species diversity (177 operational taxonomic units (OTUs)) than PCR-DGGE analysis (145 OTUs), and the species in the genera of Penicillium (relative frequency=16.8%), Fusarium (15.4%), Aspergillus (7.6%), Trichoderma (5.8%) and Talaromyces (4.2%) were dominant. On the basis of DGGE data, fungal diversity along the Changjiang River increased from upstream to downstream; altitude explained 44.8% of this variation in diversity. And based on the data from all 20 locations, the fungal communities were geographically clustered into three groups: Southern China, Northern China and the Qinghai-Tibetan Plateau. Multivariate regression tree analysis for data from the 20 locations indicated that the fungal community was influenced primarily by location (which explained 61.8% of the variation at a large scale), followed by total potassium (9.4%) and total nitrogen (3.5%) at a local scale. These results are consistent with the concept that geographic distance is the dominant factor driving variation in fungal diversity at a regional scale (1000–4000 km), whereas environmental factors (total potassium and total nitrogen) explain variation in fungal diversity at a local scale (<1000 km). PMID:23446835

Distribution, sources, and fluxes of heavy metals in the Pearl River Delta, South China.

PubMed

Geng, Junjie; Wang, Yiping; Luo, Hanjin

2015-12-30

Riverine samples were collected at various locations in the Pearl River Delta (PRD) to determine the concentrations of heavy metals (Cr, Ni, Cu, Mn, Zn, Cd, and Pb) in time and space and to estimate the fluxes of heavy metals to the coastal waters off South China. Most of the elements exhibit clear temporal and spatial trends. Principal component analysis shows that surface erosion is the major factor affecting metal concentrations in particulates in the PRD. Natural geology is an important source of these heavy metals. The annual fluxes of Cr, Ni, Cu, Mn, Zn, Cd, and Pb in upstream and downstream were 445, 256, 241, 3293, 1279, 12, and 317 t/year and 1823, 1144, 1786, 15,634, 6183, 74, and 2017 t/year, respectively. A comparison indicated that the annual fluxes of Mn accounted for 1.3% of the global river fluxes, whereas other elements contribute <1%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Trace metal pollution and carbon and nitrogen isotope tracing through the Yongdingxin River estuary in Bohai Bay, Northern China.

PubMed

Sun, Conghui; Wei, Qi; Ma, Lixia; Li, Li; Wu, Guanghong; Pan, Ling

2017-02-15

A tide gate was built in 2010 to prevent seawater from moving upstream into the Yongdingxin River estuary in Bohai Bay, Northern China. We analysed the concentrations of Hg, Cd, Pb, TOC, TN, δ 13 C and δ 15 N and studied their variations in the surface layer and vertical profiles of sediment cores collected from the Yongdingxin River estuary. Contamination factors and geo-accumulation indices were calculated for each metal, which revealed high levels of contamination for Hg and Cd in the sediments, likely from anthropogenic sources. δ 13 C and δ 15 N were used as natural tracers to determine the sources of TOC and TN. The results revealed that sewage was the main source of TOC, while TN may have more than one source in the Yongdingxin River estuary. Sewage dominated trace metal pollution in the Yongdingxin River estuary. Our results provide a baseline for trace metal contamination in an estuary facing a large water project. Copyright © 2016 Elsevier Ltd. All rights reserved.

Crustal structure of mainland China from deep seismic sounding data

USGS Publications Warehouse

Li, S.; Mooney, W.D.; Fan, J.

2006-01-01

Since 1958, about ninety seismic refraction/wide angle reflection profiles, with a cumulative length of more than sixty thousand kilometers, have been completed in mainland China. We summarize the results in the form of (1) a new contour map of crustal thickness, (2) fourteen representative crustal seismic velocity-depth columns for various tectonic units, and, (3) a Pn velocity map. We found a north-south-trending belt with a strong lateral gradient in crustal thickness in central China. This belt divides China into an eastern region, with a crustal thickness of 30-45??km, and a western region, with a thickness of 45-75??km. The crust in these two regions has experienced different evolutionary processes, and currently lies within distinct tectonic stress fields. Our compilation finds that there is a high-velocity (7.1-7.4??km/s) layer in the lower crust of the stable Tarim basin and Ordos plateau. However, in young orogenic belts, including parts of eastern China, the Tianshan and the Tibetan plateau, this layer is often absent. One exception is southern Tibet, where the presence of a high-velocity layer is related to the northward injection of the cold Indian plate. This high-velocity layer is absent in northern Tibet. In orogenic belts, there usually is a low-velocity layer (LVL) in the crust, but in stable regions this layer seldom exists. The Pn velocities in eastern China generally range from 7.9 to 8.1??km/s and tend to be isotropic. Pn velocities in western China are more variable, ranging from 7.7 to 8.2??km/s, and may display azimuthal anisotropy. ?? 2006.

Simulation of unsteady flow and solute transport in a tidal river network

USGS Publications Warehouse

Zhan, X.

2003-01-01

A mathematical model and numerical method for water flow and solute transport in a tidal river network is presented. The tidal river network is defined as a system of open channels of rivers with junctions and cross sections. As an example, the Pearl River in China is represented by a network of 104 channels, 62 nodes, and a total of 330 cross sections with 11 boundary section for one of the applications. The simulations are performed with a supercomputer for seven scenarios of water flow and/or solute transport in the Pearl River, China, with different hydrological and weather conditions. Comparisons with available data are shown. The intention of this study is to summarize previous works and to provide a useful tool for water environmental management in a tidal river network, particularly for the Pearl River, China.

Development of a model-based flood emergency management system in Yujiang River Basin, South China

NASA Astrophysics Data System (ADS)

Zeng, Yong; Cai, Yanpeng; Jia, Peng; Mao, Jiansu

2014-06-01

Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and reliability. The applied case study results show the development and application of a decision support system for real-time flood forecasting and operation is beneficial for flood control.

Evaluation of Drought Occurrence and Climate Change in the Pearl River Basin in South China

NASA Astrophysics Data System (ADS)

DU, Y.; Chen, J.; Wang, K.; Shi, H.

2015-12-01

This study uses the Variable Infiltration Capacity (VIC) Model to simulate the hydrological processes over the Pearl River basin in South China. The observed streamflow data in the Pearl River Basin for the period 1951-2000 are used to evaluate the model simulation results. Further, in this study, the 55 datasets of climate projection from 18 General Circulation Models (GCMs) for the IPCC AR4 (SRES A2/A1B/B1) and AR5 (RCP 2.6/4.5/6.0/8.5) are used to drive the VIC model at 0.5°× 0.5°spatial resolution and daily temporal resolution. Then, the monthly Standard Precipitation Index (SPI) and standardized runoff index (SRI) are generated to detect the drought occurrence. This study validates the GCMs projection through comparing the observed precipitation for the period of 2000-2013. Then, spatial variation of the frequency change of moderate drought, severe drought and extreme drought are analyzed for the 21st century. The study reveals that the frequencies of severe drought and extreme drought occurrences over the Pearl River Basin increase along with time. Specifically, for the scenario of AR5 RCP 8.5, the east and west parts of the Pearl River Basin most likely suffer from severe drought and extreme drought with an increased frequency throughout the 21st century.

Hydrological studies of the historical and palaeoflood events on the middle Yihe River, China

NASA Astrophysics Data System (ADS)

Hu, Guiming; Huang, Chun Chang; Zhou, Yali; Pang, Jiangli; Zha, Xiaochun; Guo, Yongqiang; Zhang, Yuzhu; Zhao, Xueru

2016-12-01

Palaeo-hydrological and sedimentary investigations were carried out in the Longmenxia Gorge of the middle Yihe River. Five bedsets of flood slackwater deposits (SWD) were found interbedded into Holocene aeolian loess-soil profiles in the river bank at the Longmenxia site. They were identified as the deposits of the suspended sediment load during the extreme flood events of the Holocene. The minimum flood peak discharges were estimated to be 12, 300-15, 300 m3/s using the slope-area method. These are about twice the largest gauged record (7180 m3/s) that has occurred since 1937. These flood events occurred at 3100-3000 a B.P., 1800-1700 a B.P., 700-550 a B.P. and 350-250 a B.P., as dated by optically stimulated luminescence (OSL) in combination with stratigraphic correlation, to which may be added the recorded events of the 223 and 1761 CE floods. These were associated with Holocene monsoonal shifts and abrupt climatic events. This research not only provides palaeoflood discharge estimates on the middle Yihe River, but also provides important data for understanding interactions between regional hydro-climatic systems and global climate change in humid and semi-humid monsoonal regions, such as China.

[Phylogeny and divergence time estimation of Schizothoracinae fishes in Xinjiang].

PubMed

Ayelhan, Haysa; Guo, Yan; Meng, Wei; Yang, Tianyan; Ma, Yanwu

2014-10-01

Based on combined data of mitochondrial COI, ND4 and 16S RNA genes, molecular phylogeny of 4 genera, 10 species or subspecies of Schizothoracinae fishes distributed in Xinjiang were analyzed. The molecular clock was calibrated by divergence time of Cyprininae and geological segregation event between the upper Yellow River and Qinghai Lake. Divergence time of Schizothoracinae fishes was calculated, and its relationship with the major geological events and the climate changes in surrounding areas of Tarim Basin was discussed. The results showed that genus Aspiorhynchus did not form an independent clade, but clustered with Schizothorax biddulphi and S. irregularis. Kimura 2-parameter model was used to calculate the genetic distance of COI gene, the genetic distance between genus Aspiorhynchus and Schizothorax did not reach genus level, and Aspiorhynchus laticeps might be a specialized species of genus Schizothorax. Cluster analysis showed a different result with morphological classification method, and it did not support the subgenus division of Schizothorax fishes. Divergence of two groups of primitive Schizothoracinae (8.18Ma) and divergence of Gymnodiptychus dybowskii and Diptychus maculates (7.67Ma) occurred in late Miocene, which might be related with the separation of Kunlun Mountain and north Tianshan Mountain River system that was caused by the uplift of Qinghai-Tibet Plateau and Tianshan Mountain, and the aridification of Tarim Basin. The terrain of Tarim Basin that was affected by Quaternary Himalayan movement was high in west but low in east, as a result, Lop Nor became the center of surrounding mountain rivers in Tarim Basin, which shaped the distribution pattern of genus Schizothorax.

Linkages between ENSO/PDO signals and precipitation, streamflow in China during the last 100 years

NASA Astrophysics Data System (ADS)

Ouyang, R.; Liu, W.; Fu, G.; Liu, C.; Hu, L.; Wang, H.

2014-09-01

This paper investigates the single and combined impacts of El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) on precipitation and streamflow in China over the last century. Results indicate that the precipitation and streamflow overall decrease during El Niño/PDO warm phase periods and increase during La Niña/PDO cool phase periods in the majority of China, although there are regional and seasonal differences. Precipitation and streamflow in the Yellow River basin, Yangtze River basin and Pearl River basin are more significantly influenced by El Niño and La Niña events than is precipitation and streamflow in the Songhua River basin, especially in October and November. Moreover, significant influence of ENSO on streamflow in the Yangtze River mainly occurs in summer and autumn while in the Pearl River influence primarily occurs in the winter and spring. The precipitation and streamflow are relatively greater in the warm PDO phase in the Songhua River basin and several parts of the Yellow River basin and relatively less in the Pearl River basin and most parts of Northwest China compared to those in the cool PDO phase, though there is little significance detected by Wilcoxon signed-rank test. When considering the combined influence of ENSO and PDO, the responses of precipitation/streamflow are shown to be opposite in northern China and southern China, with ENSO-related precipitation/streamflow enhanced in northern China and decreased in southern China during the warm PDO phases, and enhanced in southern China and decreased in northern China during the cool PDO phases. It is hoped that this study will be beneficial for understanding the precipitation/streamflow responses to the changing climate and will correspondingly provide valuable reference for water resources prediction and management across China.

First survey of parasitic helminths of goats along the Han River in Hubei Province, China.

PubMed

Yang, Xin; Gasser, Robin B; Fang, Rui; Zeng, Jinrong; Zhu, Kaixiang; Qi, Mingwei; Zhang, Zongze; Tan, Li; Lei, Weiqiang; Zhou, Yanqin; Zhao, Junlong; Hu, Min

2016-09-01

Diseases caused by parasitic helminths cause considerable production and economic losses in livestock worldwide. Understanding the epidemiology of these parasites has important implications for controlling them. The main purpose of the present study was to estimate the prevalence of key parasitic helminths in goats along the Han River in Zhanggang, Hubei Province (from January to December 2014). We used faecal flotation and sedimentation techniques as well as PCR-based DNA sequencing to detect and identify helminths. Results showed that the prevalence of helminths was high throughout the year, particularly for gastrointestinal nematodes. These first findings provide useful baseline information for goat helminths in Zhanggang, and a starting point for the implementation of control programs. With an increased expansion of the goat industry in China, the findings also emphasise the need to undertake prevalence surveys in other regions of China where extensive farming practices are used.

Development of upwelling on pathway and freshwater transport of Pearl River plume in northeastern South China Sea

NASA Astrophysics Data System (ADS)

Chen, Zhaoyun; Jiang, Yuwu; Liu, James T.; Gong, Wenping

2017-08-01

In situ observations, satellite images, and numerical modeling results have shown that the Pearl River plume axis extends alongshore and passes through two separate upwelling regions—one off the Guangdong and Fujian coasts (the Yuedong upwelling) and the other in the Taiwan Bank during the initial and medium stages of the Yuedong upwelling, while it is directed offshore when the Yuedong upwelling is strong. Model experiments are conducted to examine the effects of wind strength and baroclinicity on the upwelling and the corresponding pathway and freshwater transport of the Pearl River plume. The baroclinic effect is important to intensifying the horizontal velocity at the upwelling front and freshwater transport in the northeastern South China Sea. The freshwater transport flux is further decomposed into advection, vertical shear, and tidal pumping components, and advection is the dominant contributor. As the Yuedong upwelling develops, the zone with a relatively high-pressure gradient moves offshore due to offshore Ekman transport and the shift in the upwelling front, which is responsible for the offshore transport of the river plume. When the river plume is transported to the outer-shelf, sometimes it can be further entrained into eddies, allowing its export to the open sea.

Tracing sources of nitrate using water chemistry, land use and nitrogen isotopes in the Ganjiang River, China.

PubMed

Wang, Peng; Liu, Junzheng; Qi, Shuhua; Wang, Shiqin; Chen, Xiaoling

2017-10-01

In this work, we traced sources of nitrate in the Ganjiang River, a major tributary of Yangtze River, China, by analysing the water chemistry, nitrogen isotopes and land use. Water samples from 20 sites in the main stream and tributaries were collected in the dry and wet seasons. The [Formula: see text] ranged from 0.97 to 8.60 ‰, and was significantly higher in the wet season than in the dry season, and significantly higher in tributaries than in the main stream. In the dry season, [Formula: see text] concentrations and [Formula: see text] were significantly negatively correlated with forest and grassland areas, and positively correlated with paddy field and residential area. However, most of the correlations were not significant in the wet season. The results showed that fertilizer was the main source of nitrate in the Ganjiang River, and domestic sewage was important in the dry season, but its contribution was lower than that in other rivers in the Yangtze Basin. In the wet season, the intensified nitrogen cycle caused by high temperature and the mixing effect caused by rainfall made it difficult to trace nitrate sources using [Formula: see text] and land use.

Modelling and Analysis of Hydrodynamics and Water Quality for Rivers in the Northern Cold Region of China

PubMed Central

Tang, Gula; Zhu, Yunqiang; Wu, Guozheng; Li, Jing; Li, Zhao-Liang; Sun, Jiulin

2016-01-01

In this study, the Mudan River, which is the most typical river in the northern cold region of China was selected as the research object; Environmental Fluid Dynamics Code (EFDC) was adopted to construct a new two-dimensional water quality model for the urban sections of the Mudan River, and concentrations of CODCr and NH3N during ice-covered and open-water periods were simulated and analyzed. Results indicated that roughness coefficient and comprehensive pollutant decay rate were significantly different in those periods. To be specific, the roughness coefficient in the ice-covered period was larger than that of the open-water period, while the decay rate within the former period was smaller than that in the latter. In addition, according to the analysis of the simulated results, the main reasons for the decay rate reduction during the ice-covered period are temperature drop, upstream inflow decrease and ice layer cover; among them, ice sheet is the major contributor of roughness increase. These aspects were discussed in more detail in this work. The model could be generalized to hydrodynamic water quality process simulation researches on rivers in other cold regions as well. PMID:27070631

Measuring Density Stratification and Understanding its Impact on Sediment Transport in Fine-grained Rivers, Based on Observations from the Lower Yellow River, China

NASA Astrophysics Data System (ADS)

Moodie, A. J.; Nittrouer, J. A.; Ma, H.; Lamb, M. P.; Carlson, B.; Kineke, G. C.; Parker, G.

2017-12-01

High concentrations of suspended sediment in channelized fluid flow produces density stratification that can alter the turbulent flow structure, thus limiting fluid momentum redistribution and affecting sediment transport capacity. A low channel-bed slope and large flow depth are hypothesized to be additional important factors contributing to density stratification. However, there are limited observations of density stratification in large rivers, especially those that carry significant fluxes of mud, and so the conditions leading to the development of density stratification are poorly constrained. The Yellow River, China, is a fine-grained and low-sloping river that maintains some of the highest suspended sediment concentrations in large rivers worldwide, making it an ideal natural laboratory for studying density stratification and its impact on sediment transport. Suspended sediment samples from the lower Yellow River, collected over a range of discharge conditions, produced sediment concentration profiles that are used in conjunction with velocity profiles to determine the threshold shear velocity for density stratification effects to develop. Comparing measured and predicted concentration and velocity profiles demonstrates that, there is no significant density stratification for base flow conditions; however, above a shear velocity value of 0.05 m/s, there is a progressive offset between the measured and predicted profiles, indicating that density stratification is increasingly important with higher shear stress values. The analyses further indicate that sediment entrainment from the bed and sediment diffusivity within the water column are significantly impacted by density stratification, suggesting that shear stress and sediment transport rates are inhibited by the development of density stratification. Near-bed concentration measurements are used to assess a stress-to-entrainment relationship, accounting for density stratification. These measurements are

Spatio-temporal pattern of schistosomiasis in Anhui Province, East China: Potential effect of the Yangtze River - Huaihe River Water Transfer Project.

PubMed

Cao, Zhi-Guo; Li, Si; Zhao, Ya-E; Wang, Tian-Ping; Bergquist, Robert; Huang, Yin-Yin; Gao, Feng-Hua; Hu, Yi; Zhang, Zhi-Jie

2018-05-09

Anhui Province has been one of typical epidemic areas of schistosomiasis in East China as a wide range of large lake and marshland regions provide an ideal environment for growth and reproduction of the intermediate snail host. With the completion of the Yangtze River-Huaihe River Water Transfer Project (YHWTP), launched by the end of 2016, the epidemic areas are expected to expand and controlling schistosomiasis remains a challenge. Based on annual surveillance data at the county level in Anhui for the period 2006-2015, spatial and temporal cluster analyses were conducted to assess the pattern of risk through spatial (Local Moran's I and flexible scan statistic) and space-time scan statistic (Kulldorff). It was found that schistosomiasis sero-prevalence was dramatically reduced and maintained at a low level. Cluster results showed that spatial extent of schistosomiasis contracted, but snail distribution remained geographically stable across the study area. Clusters, both for schistosomiasis and snail presence, were common along the Yangtze River. Considering the effect of the ongoing YHWTP on the potential spread of schistosomiasis, Zongyang County and Anqing, which will be transected by the new water-transfer route, should be given a priority for strengthened surveillance and control. Attention should also be paid to Guichi since it is close to one of the planned inlets of the YHWTP. Copyright © 2018 Elsevier B.V. All rights reserved.

Polycyclic aromatic hydrocarbons in water, sediment, soil, and plants of the Aojiang River waterway in Wenzhou, China

PubMed Central

Li, Jianwang; Shang, Xu; Zhao, Zhixu; Tanguay, Robert L.; Dong, Qiaoxiang; Huang, Changjiang

2012-01-01

The town of Shuitou was renowned as the leather capital of China because of its large-scale tanning industry, but the industry’s lack of pollution controls has caused severe damage to the local water system. This study determined 15 priority polycyclic aromatic hydrocarbons (PAHs) in water, sediment, soil, and plant samples collected from Aojiang River and its estuary. The total PAHs ranged from 910 to 1520 ng/L in water samples. The total PAH in sediments were moderate to low in comparison with other rivers and estuaries in China, but the relative proportions of PAHs per million people are high when considering the population size associated with each watershed. Ratios of fluoranthene/pyrene and PAHs with low/high molecular weight suggest a petrogenic PAH origin. The PAH composition profile in soil was similar to that in sediment with 4–6 ring PAHs being dominant. The PAHs with 2–3 rings were the dominant species in plant leaves. There were no correlations between PAHs in soils and in plants, suggesting that PAHs accumulate in plant leaves through absorption from the air. The general observation of elevated PAH concentrations in all matrix suggests a possible contribution by the local leather industry on the PAH concentrations in the Aojiang watershed. PMID:19726127

Restoring ecosystem services to littoral zones of rivers in the urban core of Chongqing, China.

PubMed

Xian, Xu-Dong; Feng, Yi-Long; Willison, J H Martin; Ai, Li-Jiao; Wang, Ping; Wu, Zhi-Neng

2015-08-01

Two examples of the creation of naturalized areas in the littoral zone of the Three Gorges Reservoir in the urban core of Chongqing City, China, are described. The areas were created for the purpose of restoring ecological functions and services. Plants were selected based on surveys of natural wetland vegetation in the region, and experiments were conducted to discover the capacity of species of interest to survive the sometimes extreme hydrological regimes at the sites. Novel methods were developed to stabilize the plants against the rigors of extreme summer floods and constant swash, notably zigzag berms of rocks wrapped in iron mesh. The areas include native reeds, grasses, shrubs, and trees. Plant communities in the areas are zoned according to flooding stress, and their structure is less stable at lower elevations that are subjected to greater stress. The tall grass Saccharum spontaneum (widespread in Southern Asia) and the tree Pterocarya stenoptera (native to Southwest China) are notable for their utility at these sites in the center of a large city. Communities of tall reeds and grasses have become so dense and stable that they now provide the ecosystem services of capturing river sediments and resisting erosion of the river banks. It is recommended that extensive greening of the riparian zones in urban areas of the Three Gorges Reservoir be conducted for the purpose of providing ecosystem services, based in part on the experiences described here.

Sacred rivers: their spiritual significance in Hindu religion.

PubMed

Agoramoorthy, Govindasamy

2015-06-01

The ancient civilizations in India, China, Egypt and Mesopotamia have flourished due to large rivers that provided water for agriculture over millennia. Egypt was able to grow well because of the Nile. Similarly, Mesopotamia had two rivers namely the Tigris and the Euphrates. Likewise, India and China have several great rivers that continue to support the agrarian culture. This article discusses the sacred significance of rivers in the ancient and contemporary Indian culture with examples from popular Hindu scriptures. It also presents the ancient model of an eco-friendly check dam and its modern application with potential to mitigate future water-related problems across the drylands of India and elsewhere.

Occurrence and transport of tetracycline, sulfonamide, quinolone, and macrolide antibiotics in the Haihe River Basin, China.

PubMed

Luo, Yi; Xu, Lin; Rysz, Michal; Wang, Yuqiu; Zhang, Hao; Alvarez, Pedro J J

2011-03-01

The occurrence and transport of 12 antibiotics (from the tetracycline, sulfonamide, quinolone, and macrolide families) was studied in a 72-km stretch of the Haihe River, China, and in six of its tributaries. Aqueous and sediment samples were analyzed by HPLC-MS/MS. Sulfonamides were detected at the highest concentrations (24-385 ng/L) and highest frequencies (76-100%). Eight of the 12 antibiotics likely originated from veterinary applications in swine farms and fishponds, and concentrations at these sources (0.12-47 μg/L) were 1-2 orders of magnitude higher than in the effluent of local wastewater treatment plants. Sulfachloropyridazine (SCP) was detected in all swine farm and fishpond samples (maximum concentration 47 μg/L), which suggests its potential usefulness to indicate livestock source pollution in the Haihe River basin. Hydrological and chemical factors that may influence antibiotic distribution in the Haihe River were considered by multiple regression analysis. River flow rate exerted the most significant effect on the first-order attenuation coefficient (K) for sulfonamides, quinolones, and macrolides, with higher flow rates resulting in higher K, probably due to dilution. For tetracyclines, sediment total organic matter and cation exchange capacity exerted a greater impact on K than flow rate, indicating that adsorption to sediments plays an important role in attenuating tetracycline migration. Overall, the predominance of sulfonamides in the Haihe River underscores the need to consider regulating their veterinary use and improving the management and treatment of associated releases.

Heavy Metal Accumulation by Periphyton Is Related to Eutrophication in the Hai River Basin, Northern China

PubMed Central

Tang, Wenzhong; Cui, Jingguo; Shan, Baoqing; Wang, Chao; Zhang, Wenqiang

2014-01-01

The Hai River Basin (HRB) is one of the most polluted river basins in China. The basin suffers from various types of pollutants including heavy metals and nutrients due to a high population density and rapid economic development in this area. We assessed the relationship between heavy metal accumulation by periphyton playing an important role in fluvial food webs and eutrophication in the HRB. The concentrations of the unicellular diatoms (type A), filamentous algae with diatoms (type B), and filamentous algae (type C) varied along the river, with type A dominating upstream, and types B then C increasing in concentration further downstream, and this was consistent with changes in the trophic status of the river. The mean heavy metal concentrations in the type A, B and C organisms were Cr: 18, 18 and 24 mg/kg, respectively, Ni: 9.2, 10 and 12 mg/kg, respectively, Cu: 8.4, 19 and 29 mg/kg, respectively, and Pb: 11, 9.8 and 7.1 mg/kg respectively. The bioconcentration factors showed that the abilities of the organisms to accumulate Cr, Ni and Pb decreased in the order type A, type B, then type C, but their abilities to accumulate Cu increased in that order. The Ni concentration was a good predictor of Cr, Cu and Pb accumulation by all three periphyton types. Our study shows that heavy metal accumulation by periphyton is associated with eutrophication in the rivers in the HRB. PMID:24482681

Polycyclic aromatic hydrocarbons in sediments from the Old Yellow River Estuary, China: occurrence, sources, characterization and correlation with the relocation history of the Yellow River.

PubMed

Yuan, Zijiao; Liu, Guijian; Wang, Ruwei; Da, Chunnian

2014-11-01

The levels of 16 USEPA priority PAHs were determined in surface sediments and one dated sediment core from the abandoned Old Yellow River Estuary, China. Total PAH concentrations in the surface sediments ranged from 100.4 to 197.3 ng g(-1) dry weight and the total toxic equivalent quantity (TEQ(carc)) values of the carcinogenic PAHs were very low. An evaluation of PAH sources based on diagnostic ratios and principal component analysis suggested that PAHs in the surface sediments mainly derived from combustion sources. The total PAH concentrations altered significantly with year of deposition and showed quite different patterns of change compared with other studies: it is hypothesized that the principal cause of these changes is the relocation of the course of the Yellow River to the sea in 1976 and 1996. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluating a 5-year metal contamination remediation and the biomonitoring potential of a freshwater gastropod along the Xiangjiang River, China.

PubMed

Li, Deliang; Pi, Jie; Zhang, Ting; Tan, Xiang; Fraser, Dylan J

2018-05-16

Effective remediation of heavy metal pollution in aquatic systems is desired in many regions, but it requires integrative assessments of sediments, water, and biota that can serve as robust biomonitors. We assessed the effects of a 5-year metal contamination remediation along the Xiangjiang River, China, by comparing concentrations of trace metals in water and surface sediments between 2010-2011 and 2016. We also explored the trace metal biomonitoring potential of a freshwater gastropod (Bellamya aeruginosa). Metal concentrations in water (means and ranges) dropped over time to within permissible limits of drinking water guidelines set by China, USEPA, and WHO in 2016. Although sediment means and ranges of Cd, Pb, Zn, and Mn also diminished with remediation, those for Cr and Cu slightly increased, and all six metals retained concentrations higher than standards set by China. All metals in sediments could also be associated with anthropogenic inputs using a hierarchical clustering analysis, and they generate high potential ecological risks based on several indices, especially for Cd and As. The bio-sediment accumulation factors of all measured trace metals in gastropod soft tissues and shells were lower than 1.0, except for Ca. Trace metal contents in gastropods were positively correlated with those in water and surface sediments for As (soft tissues) and Cr (shells). Collectively, our results do not yet highlight strong beneficial effects of 5-year remediation and clearly illustrate the heavy metal pollution remaining in Xiangjiang River sediment. Additional physical, chemical, and biological measurements should be implemented to improve sediment quality. We further conclude that gastropod soft tissues and shells can be suitable biomonitors of spatial differences in some heavy metals found within river sediments (e.g., As, Cr).

Genotoxicity and cytotoxicity reduction of the polluted urban river after ecological restoration: a field-scale study of Jialu River in northern China.

PubMed

Sun, Jie; Zhang, Rui; Qin, Long; Zhu, Haixiao; Huang, Yu; Xue, Yingang; An, Shuqing; Xie, Xianchuan; Li, Aimin

2017-03-01

To further treat the reclaimed municipal wastewater and rehabilitate the aquatic ecosystem of polluted urban rivers, an 18.5-km field-scale ecological restoration project was constructed along Jialu River, a polluted urban river which receives only reclaimed municipal wastewater from Zhengzhou City without natural upland water dilution. This study investigated the potential efficiency of water quality improvement, as well as genotoxicity and cytotoxicity reduction along the ecological restoration project of this polluted urban river. Results showed that the chemical oxygen demand (COD) and ammonia nitrogen (NH 3 -N) of the reclaimed municipal effluent were reduced by more than 45 and 70%, respectively, meeting the Chinese surface water environmental quality standard level IV, while the total phosphorus and metal concentrations had no significant reduction along the restoration project, and Pb concentrations in all river water samples exceeded permissible limit in drinking water set by WHO (2006) and China (GB5749-2006). The in vitro SOS/umu assay showed 4-nitroquinoline-1-oxide equivalent (4-NQO-EQ) values of reclaimed municipal wastewater of 0.69 ± 0.05 μg/L in April and 0.68 ± 0.06 μg/L in December, respectively, indicating the presence of genotoxic compounds. The results of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hepatic cell apoptosis in zebrafish after a chorionic long-term (21 days) in vivo exposure also demonstrated that the reclaimed municipal wastewater caused significant DNA oxidative damage and cytotoxicity. After the ecological purification of 18.5-km field-scale restoration project, the genotoxicity assessed by in vitro assay was negligible, while the DNA oxidative damage and cytotoxicity in exposed fish were still significantly elevated. The mechanisms of DNA oxidative damage and cytotoxicity caused by the reclaimed municipal wastewater need further study.

Kinematics of Active Deformation Across the Western Kunlun Mountain Range (Xinjiang, China) and Potential Seismic Hazards Within the Southern Tarim Basin

NASA Astrophysics Data System (ADS)

Guilbaud, Christelle; Simoes, Martine; Barrier, Laurie; Laborde, Amandine; Van der Woerd, Jérôme; Li, Haibing; Tapponnier, Paul; Coudroy, Thomas; Murray, Andrew

2017-12-01

The Western Kunlun mountain range is a slowly converging intracontinental orogen where deformation rates are too low to be properly quantified from geodetic techniques. This region has recorded little seismicity, but the recent July 2015 (Mw 6.4) Pishan earthquake shows that this mountain range remains seismic. To quantify the rate of active deformation and the potential for major earthquakes in this region, we combine a structural and quantitative morphological analysis of the Yecheng-Pishan fold, along the topographic mountain front in the epicentral area. Using a seismic profile, we derive a structural cross section in which we identify the fault that broke during the Pishan earthquake, an 8-12 km deep blind ramp beneath the Yecheng-Pishan fold. Combining satellite images and DEMs, we achieve a detailed morphological analysis of the Yecheng-Pishan fold, where we find nine levels of incised fluvial terraces and alluvial fans. From their incision pattern and using age constraints retrieved on some of these terraces from field sampling, we quantify the slip rate on the underlying blind ramp to 0.5 to 2.5 mm/yr, with a most probable long-term value of 2 to 2.5 mm/yr. The evolution of the Yecheng-Pishan fold is proposed by combining all structural, morphological, and chronological observations. Finally, we compare the seismotectonic context of the Western Kunlun to what has been proposed for the Himalayas of Central Nepal. This allows for discussing the possibility of M ≥ 8 earthquakes if the whole decollement across the southern Tarim Basin is seismically locked and ruptures in one single event.

[Effects of thinning on Calligonum arborescens growth and soil water-salt distribution in Tarim Desert Highway shelterbelt, Xinjiang of Northwest China].

PubMed

Zhang, Jian-Guo; Li, Ying-Gang; Xu, Xin-Wen; Lei, Jia-Qiang; Li, Sheng-Yu

2012-09-01

In order to understand the effects of thinning on the growth of Calligonum arborescens and the soil water-salt distribution in Tarim Desert Highway shelterbelt, a thinning experiment was conducted on an aged and declined C. arborescens woodland in a demonstration section of the shelterbelt, with the growth of C. arborescens and the soil water-salt distribution monitored. Thinning had no effects on the phenophase of C. arborescens, but after thinning, the growth of the current year plant height, crown width, ground diameter, and new branch length of reserved trees was larger than that of the control, and the increment was in the order of planting space 2 mx 1 m > 1 m x 1 m > the control, with significant differences among the treatments. The assimilation branch surface area in treatments 2 mx 1 m and 1 m x 1 m were 5.97 m2 and 5.22 m2 per plant, respectively, being significantly larger than the control (3.1 m2 per plant). The soil moisture content in 0-160 cm layer was significantly higher in treatments 2 m x 1 m and 1 mx 1 m than in the control, and increased obviously with thinning intensity. The soil salt content was in the order of control > planting space 1 m x 1 m > 2 m x 1 m, and the differences among the treatments were significant. It was suggested that the best reserved plant density after thinning was planting space 2 m x 1 m.

Public perception of an ecological rehabilitation project in inland river basins in northern China: Success or failure.

PubMed

Feng, Qi; Miao, Zheng; Li, Zongxing; Li, Jianguo; Si, Jianhua; S, Yonghong; Chang, Zongqiang

2015-05-01

The need for environmental protection challenges societies to deal with difficult problems because strategies designed by scientists to protect the environment often create negative effects on impoverished local residents. We investigated the effects of China's national and regional policies related to environmental protection and rehabilitation projects in inland river basins, by studying the effect of projects in the Heihe and Shiyang river basins, in northwest China. Interviews and surveys were conducted at 30 sites in the lower reaches of these two arid basins, an area that has experienced severe ecological degradation. The survey results show the ecological rehabilitation projects adversely affected the livelihoods of 70.35% of foresters, 64.89% of farmers and 62.24% of herders in the Minqing region in the lower Shiyang River Basin; also, the projects negatively affected 51.9% of residents in the Ejin Qi in the lower Heihe River Basin. This caused 16.33% of foresters, 39.90% of farmers and 45.32% of herders in the Minqing region to not support the project and 37.5% of residents in the Ejin Qi region said they will deforest and graze again after the project ends. The negative impacts of the policies connected to the projects cause these attitudes. The projects prohibit felling and grazing and require residents to give up groundwater mining; this results in a great amount of uncompensated economic loss to them. Extensive survey data document the concerns of local residents, concerns that are supported by the calculation of actual incomes. In addition, the surveys results show poorer interviewees believe the projects greatly affected their livelihoods. While citizens in this region support environment protection work, the poor require considerable assistance if one expects them to support this type of work. Governmental assistance can greatly improve their living conditions, and hence encourage them to participate in and support the implementation of the projects

Anthropogenic impact on biogenic substance distribution and bacterial community in sediment along the Yarlung Tsangpo River on Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Wang, C.; Peifang, W.; Wang, X.; Hou, J.; Miao, L.

2017-12-01

Lotic river system plays an important part in water-vapor transfer and biogenic substances migration and transformation. Anthropogenic activities, including wastewater discharging and river damming, have altered river ecosystem and continuum. However, as the longest alpine river in China and suffered from increasing anthropogenic activities, the Yarlung Tsangpo River has been rarely studied. Recently, more attention has also been paid to the bacteria in river sediment as they make vital contributions to the biogeochemical nutrient cycling. Here, the distribution of biogenic substances, including nitrogen, phosphorus, silicon and carbon, was explored in both water and sediment of the Yarlung Tsangpo River. By using the next generation 16S rRNA sequencing, the bacterial diversity and structure in river sediment were presented. The results indicated that the nutrient concentrations increased in densely populated sites, revealing that biogenic substance distribution corresponded with the intensity of anthropogenic activity along the river. Nitrogen, phosphorus, silicon and carbon in water and sediment were all retained by the Zangmu Dam which is the only dam in the mainstream of the river. Moreover, the river damming decreased the biomass and diversity of bacteria in sediment, but no significant alteration of community structure was observed upstream and downstream of the dam. The most dominant bacteria all along the river was Proteobacteria. Meanwhile, Verrucomicrobia and Firmicutes also dominated the community composition in upstream and downstream of the river, respectively. In addition, total organic carbon (TOC) was proved to be the most important environmental factor shaping the bacterial community in river sediment. Our study offered the preliminary insights into the biogenic substance distribution and bacterial community in sediment along an alpine river which was affected by anthropogenic activities. In the future, more studies are needed to reveal the

Direct dating of left-lateral deformation along the Red River shear zone, China and Vietnam

NASA Astrophysics Data System (ADS)

Gilley, Lisa D.; Harrison, T. Mark; Leloup, P. H.; Ryerson, F. J.; Lovera, Oscar M.; Wang, Jiang-Hai

2003-02-01

Exposures of high-grade, midcrustal rocks within the Red River shear zone (RRSZ), which separates the Indochina and South China blocks, exhibit clear evidence of left-lateral, ductile deformation. Assuming that the South China Sea represents a pull-apart basin formed at the southeastern termination of the RRSZ, it has been argued that seafloor magnetic anomalies constrain the timing of sinistral slip accommodated by the RRSZ between ˜32 and 17 Ma at a rate of ˜4 cm/yr. While 40Ar/39Ar thermochronometry indicates that left-lateral slip occurred along the RRSZ between 25 and 17 Ma, the timing of earlier high-temperature deformation has not been directly constrained. In situ Th-Pb ion microprobe dating of monazite inclusions in garnets allows direct assessment of the timing of amphibolite-grade metamorphism and synchronous left-lateral shearing. Results from northern segments of the RRSZ in Yunnan, China, indicate that synkinematic garnet growth occurred between 34 and 21 Ma and are the first to document late Oligocene metamorphism and left-lateral shearing. Data from the southern RRSZ within Vietnam are complicated by Tertiary overprinting of rocks that experienced amphibolite facies metamorphism during the Indosinian orogeny (˜220 Ma). The period during which sinistral deformation is now constrained to have occurred along the RRSZ (i.e., 34-17 Ma) is essentially coincident with spreading of the South China seafloor (32-17 Ma). This temporal and kinematic link between left-lateral shearing along the RRSZ and opening of the South China Sea supports the view that Indochina was extruded from Asia as a block along lithospheric-scale strike-slip faults.

Evolution of the great river systems of southern Asia during the Cenozoic India-Asia collision: Rivers draining north from the Pamir syntaxis

NASA Astrophysics Data System (ADS)

Brookfield, M. E.

2008-08-01

During uplift of the Tibetan plateau and surrounding ranges, tectonic processes have interacted with climatic change and with local random effects (such as landslides) to determine the development of the major river systems of Asia. Rivers draining northward from the Pamir syntaxis have three distinctive patterns that are controlled by different tectonic and climatic regimes. West of the Pamir, the rivers have moderate but irregular gradients and drain northwards to disappear into arid depressions. Relatively steady uplift of the Hindu Kush in northern Afghanistan allowed rivers to cut across the rising ranges, modified by the shear along the Harirud fault zone, local faulting, and by increasing rain-shadow effects from the rising Makran. In the transition to the Pamir the rivers have steeper but more even gradients suggesting more even flow and downcutting during uplift, possibly related to larger glacial sources. In the central Pamir, only one antecedent river, the Pyandzh appears to have kept its northward course with compression and uplift of the indenter, and its course strangely corresponds with a major geophysical boundary (a distorted subducted slab) but not a geological boundary: the other rivers are subsequent rivers developed along deformation fronts during development and northward displacements of the Pamir structural units. The above areas have sources north of the Cretaceous Karakorum-South Pamir Andean margin. On the eastern flank of the Pamir, in the Kunlun and northern Tibetan plateau, the rivers rise similarly north of the Cretaceous Andean margin of southern Tibet, but then flow with low gradients across the plateau, before cutting and plunging steeply down across the Kunlun to disappear into the arid Tarim. These steep profiles are the result of late Neogene uplift of the northern Tibetan plateau and Kunlun possibly modified by glacial diversion and river capture. The drainage history of the Pamir indenter can be reconstructed by restoring the

Water geochemistry of the Qiantangjiang River, East China: Chemical weathering and CO2 consumption in a basin affected by severe acid deposition

NASA Astrophysics Data System (ADS)

Liu, Wenjing; Shi, Chao; Xu, Zhifang; Zhao, Tong; Jiang, Hao; Liang, Chongshan; Zhang, Xuan; Zhou, Li; Yu, Chong

2016-09-01

The chemical composition of the Qiantangjiang River, the largest river in Zhejiang province in eastern China, was measured to understand the chemical weathering of rocks and the associated CO2 consumption and anthropogenic influences within a silicate-dominated river basin. The average total dissolved solids (TDS, 113 mg l-1) and total cation concentration (TZ+, 1357 μeq l-1) of the river waters are comparable with those of global major rivers. Ca2+ and HCO3- followed by Na2+ and SO42-, dominate the ionic composition of the river water. There are four major reservoirs (carbonates, silicates, atmospheric and anthropogenic inputs) contributing to the total dissolved load of the investigated rivers. The dissolved loads of the rivers are dominated by both carbonate and silicate weathering, which together account for about 76.3% of the total cationic load origin. The cationic chemical weathering rates of silicate and carbonate for the Qiantangjiang basin are estimated to be approximately 4.9 ton km-2 a-1 and 13.9 ton km-2 a-1, respectively. The calculated CO2 consumption rates with the assumption that all the protons involved in the weathering reaction are provided by carbonic acid are 369 × 103 mol km-2 a-1 and 273 × 103 mol km-2 a-1 by carbonate and silicate weathering, respectively. As one of the most severe impacted area by acid rain in China, H2SO4 from acid precipitation is also an important proton donor in weathering reactions. When H2SO4 is considered, the CO2 consumption rates for the river basin are estimated at 286 × 103 mol km-2 a-1 for carbonate weathering and 211 × 103 mol km-2 a-1 for silicate weathering, respectively. The results highlight that the drawdown effect of CO2 consumption by carbonate and silicate weathering can be largely overestimated if the role of sulfuric acid is ignored, especially in the area heavily impacted by acid deposition like Qiantangjiang basin. The actual CO2 consumption rates (after sulfuric acid weathering effect

Design rainfall depth estimation through two regional frequency analysis methods in Hanjiang River Basin, China

NASA Astrophysics Data System (ADS)

Xu, Yue-Ping; Yu, Chaofeng; Zhang, Xujie; Zhang, Qingqing; Xu, Xiao

2012-02-01

Hydrological predictions in ungauged basins are of significant importance for water resources management. In hydrological frequency analysis, regional methods are regarded as useful tools in estimating design rainfall/flood for areas with only little data available. The purpose of this paper is to investigate the performance of two regional methods, namely the Hosking's approach and the cokriging approach, in hydrological frequency analysis. These two methods are employed to estimate 24-h design rainfall depths in Hanjiang River Basin, one of the largest tributaries of Yangtze River, China. Validation is made through comparing the results to those calculated from the provincial handbook approach which uses hundreds of rainfall gauge stations. Also for validation purpose, five hypothetically ungauged sites from the middle basin are chosen. The final results show that compared to the provincial handbook approach, the Hosking's approach often overestimated the 24-h design rainfall depths while the cokriging approach most of the time underestimated. Overall, the Hosking' approach produced more accurate results than the cokriging approach.

Employee Training Needs and Perceived Value of Training in the Pearl River Delta of China: A Human Capital Development Approach

ERIC Educational Resources Information Center

Au, Alan Kai Ming; Altman, Yochanan; Roussel, Josse

2008-01-01

Purpose: This paper aims to explore Hong Kong firms' training needs in the Pearl River Delta, a booming region in the fast growing People Republic of China economy, by resorting to a human capital approach. Also, to identify the training policies selected by those firms in order to cater for those needs. Design/methodology/approach: A survey based…

Environmental lead pollution threatens the children living in the Pearl River Delta region, China.

PubMed

Chen, Jianmin; Tong, Yongpeng; Xu, Jiazhang; Liu, Xiaoli; Li, Yulan; Tan, Mingguang; Li, Yan

2012-09-01

The objective of this study is to determine children's blood lead levels and identify sources of lead exposure. Childhood lead exposure constitutes a major pediatric health problem today in China. A blood lead screening survey program for children in the age group of 2-12 years residing in Pearl River Delta region, south of China, was carried out from Dec 2007 to Jan 2008. Blood lead levels and lead isotope ratios of a total of 761 participants were assessed by inductively coupled plasma mass spectroscopy. Measurements of urban environmental samples for source identification of children lead exposure were also performed. The geometric mean value of the children's blood lead levels was 57.05 μg/L, and 9.6% of them were higher than 100 μg/L. The blood lead levels were still much higher than those in developed countries. Based on the data of environmental lead source inventories, lead isotopic tracing revealed that there is about 6.7% past used gasoline Pb embedded in Shenzhen residential dust and about 15.6% in Guangzhou dust, respectively.

Evaluation of blue and green water resources in the upper Yellow River basin of China

NASA Astrophysics Data System (ADS)

Gao, Xiaoxi; Zuo, Depeng; Xu, Zongxue; Cai, Siyang; Xianming, Han

2018-06-01

The total amount of water resources severely affects socioeconomic development of a region or watershed, which means that accurate quantification of the total amount of water resources is vital for the area, especially for the arid and semi-arid regions. Traditional evaluation of water resources only focused on the qualification of blue water, while the importance of green water was not fully considered. As the second largest river in China, the Yellow River plays an important role in socioeconomic development of the Yellow River basin. Therefore, the blue and green water resources in the upper Yellow River basin (UYRB) were evaluated by the SWAT model in this study. The results show that the average annual total amount of water resources in the UYRB was 140.5 billion m3, in which the blue water resources is 37.8 billion m3, and green water resources is 107.7 billion m3. The intra-annual variability of the blue water and green water is relatively similar during the same period. The higher temperature, the greater difference between the blue and green water. The inter-annual variability of the blue and green water shows that the trends in precipitation, blue and green water have a relatively similar characteristic. The spatial distribution of the blue and green water is characteristic with gradually decreasing from the northwest to the southeast, and the blue water around the main stream is greater than that in the other areas.

Carbonate system and nutrients in the Pearl River estuary, China: Seasonal and inter-annual variations

NASA Astrophysics Data System (ADS)

Guo, X.

2017-12-01

Located in southern China and surrounded by several metropolis, the Pearl River estuary is a large subtropical estuary under significant human perturbation. We examined the impact of sewage treatment rate on the water environmental factors. Carbonate system parameters (Dissolved inorganic carbon or DIC, Total alkalinity or TA, and pH), and nutrients were surveyed in the Pearl River estuary from 2000 to 2015. Spatially, concentrations of nutrients were high at low salinity and decreased with salinity in both wet and dry seasons although seasonal variation occurred. However, distribution patterns of DIC and TA differed in wet and dry seasons. In wet season, both DIC and TA were low at low salinity (600-1500 umol kg-1) and increased with salinity, but in dry season they were high at low salinity (3000-3500 umol kg-1) and decreased with salinity. Compared with the years before 2010, both values and distribution patterns of DIC, TA and pH were similar among the years in wet season, but they were conspicuously different in the upper estuary in dry season. Both DIC and TA were more than 1000 umol kg-1 lower than those in the years before 2010. For nutrients at low salinity, the ammonia concentration was much lower in the years after 2010 (200 vs. 400 umol kg-1 in wet season and 400 vs. 800 umol kg-1 in dry season), but nitrate concentration was slightly higher (180 vs 120 mmol kg-1 in wet season and 200 vs 180 mmol kg-1 in dry season). As a reference, carbonate system parameters and nutrients were stable among the 16 years in the adjacent northern South China Sea. The variations in biogeochemical processes induced by nutrients concentration and structure as a result of sewage discharge will be discussed in detail. The decrease in DIC, TA and nutrients in the upper Pearl River estuary after 2010 was due mainly to the improvement of sewage treatment rate and capacity.

Modeling of soil erosion and sediment transport in the East River Basin in southern China.

PubMed

Wu, Yiping; Chen, Ji

2012-12-15

Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide. Published by Elsevier B.V.

Modeling of soil erosion and sediment transport in the East River Basin in southern China

USGS Publications Warehouse

Wu, Yping; Chen, Ji

2012-01-01

Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide.

Water transparency distribution under varied currents in the largest river-connected lake of China.

PubMed

Wang, Hua; Zhao, Yijun; Zhang, Zhizhang; Pang, Yong; Liang, Dongfang

2017-01-01

Water transparency is an important ecological indicator for shallow lakes. The largest shallow lake, Poyang Lake, as well as the most typical river-connected lake in China was selected as the research area. In view of the complicated water-sediment conditions induced by its frequent water exchange with external rivers, the dominant factors driving water transparency were determined against the field investigated data from 2003 to 2013 and a specific driving function was established. A numerical model coupling suspended sediment, Chl-a and chemical oxygen demand was developed and validated, and the spatial water transparency distributions under three typical current structures in Poyang Lake, Gravity-style, Jacking-style and Backflow-style, were quantitatively estimated. The following results stood out: water transparency in the lake varied distinctly with the current status; Backflow-style current was basically characterized by the lowest water transparency, while that under Jacking-style was the highest due to the lower sediment carrying capacity. In some outlying regions in the lake, where the water current is hardly influenced by the mainstream, the water transparency was always kept at a stable level.

Ecosystem Health Assessment in the Pearl River Estuary of China by Considering Ecosystem Coordination

PubMed Central

Chen, Xiaoyan; Gao, Huiwang; Yao, Xiaohong; Chen, Zhenhua; Fang, Hongda; Ye, Shufeng

2013-01-01

Marine ecosystem is a complex nonlinear system. However, ecosystem health assessment conventionally builds on a linear superposition of changes in ecosystem components and probably fails to evaluate nonlinear interactions among various components. To better reflect the intrinsic interactions and their impacts on ecosystem health, an ecosystem coordination index, defined as the matching level of ecosystem structure/services, is proposed and incorporated into the ecosystem health index for a systematic diagnosis in the Pearl River Estuary, China. The analysis results show that the ecosystem health index over the last three decades decreased from 0.91 to 0.50, indicating deteriorating from healthy to unhealthy status. The health index is 3–16% lower than that calculated using the common method without considering ecosystem coordination. Ecosystem health degradation in the Pearl River Estuary manifested as significant decreases in structure/services and somewhat mismatching among them. Overall, the introduction of coordination in ecosystem health assessment could improve the understanding of the mechanism of marine ecosystem change and facilitate effective restoration of ecosystem health. PMID:23894670

Characteristics of soil C:N ratio and δ13C in wheat-maize cropping system of the North China Plain and influences of the Yellow River.

PubMed

Shi, Huijin; Wang, Xiujun; Xu, Minggang; Zhang, Haibo; Luo, Yongming

2017-12-04

To better understand the characteristics of soil organic matter (SOM) in the North China Plain, we evaluate the large scale variations of soil organic carbon (SOC), total nitrogen (TN), carbon to nitrogen (C:N) ratio and stable carbon isotopic compositions (δ 13 C) in SOC over 0-100 cm. To assess the influence of the Yellow River, 31 sites are selected from the wheat-maize double cropping system, and grouped into two: 10 sites near and 21 sites far from the river. Our data show that mean soil C:N ratio is low (7.6-9.9) across the region, and not affected by the Yellow River. However, SOC and TN are significantly (P < 0.05) lower in subsoil near the Yellow River (2.0 and 0.2-0.3 g kg -1 for SOC and TN) than far away (3.1 and 0.4 g kg -1 ); δ 13 C is significantly more negative below 60 cm near the river (-23.3 to -22.6‰) than far away (-21.8 to -21.4‰). We estimate that the contributions of wheat and maize to SOC are 61.3-68.1% and 31.9-38.8%, respectively. Our analyses indicate that the overall low levels of SOC in the North China Plain may be associated with the low soil C:N ratio and less clay content. The hydrological processes may also partly be responsible, particularly for those near the Yellow River.

Heavy metals in surface sediments of the Jialu River, China: their relations to environmental factors.

PubMed

Fu, Jie; Zhao, Changpo; Luo, Yupeng; Liu, Chunsheng; Kyzas, George Z; Luo, Yin; Zhao, Dongye; An, Shuqing; Zhu, Hailiang

2014-04-15

This work investigated heavy metal pollution in surface sediments of the Jialu River, China. Sediment samples were collected at 19 sites along the river in connection with field surveys and the total concentrations were determined using atomic fluorescence spectrometer and inductively coupled plasma optical emission spectrometer. Sediment samples with higher metal concentrations were collected from the upper reach of the river, while sediments in the middle and lower reaches had relatively lower metal concentrations. Multivariate techniques including Pearson correlation, hierarchical cluster and principal components analysis were used to evaluate the metal sources. The ecological risk associated with the heavy metals in sediments was rated as moderate based on the assessments using methods of consensus-based Sediment Quality Guidelines, Potential Ecological Risk Index and Geo-accumulation Index. The relations between heavy metals and various environmental factors (i.e., chemical properties of sediments, water quality indices and aquatic organism indices) were also studied. Nitrate nitrogen, total nitrogen, and total polycyclic aromatic hydrocarbons concentrations in sediments showed a co-release behavior with heavy metals. Ammonia nitrogen, total nitrogen, orthophosphate, total phosphate and permanganate index in water were found to be related to metal sedimentation. Heavy metals in sediments posed a potential impact on the benthos community. Copyright © 2014 Elsevier B.V. All rights reserved.

Nutrient (N, P) budgets for the Red River basin (Vietnam and China)

NASA Astrophysics Data System (ADS)

Quynh, Le Thi Phuong; Billen, Gilles; Garnier, Josette; ThéRy, Sylvain; FéZard, CéDric; Minh, Chau Van

2005-06-01

In order to examine the degree of human-induced alteration of the nitrogen and phosphorus cycles at the scale of a tropical watershed of regional dimension, the budgets of these two elements were estimated in the four main sub-basins (Da, Lo, Thao, and Delta) of the Red River system (156 448 km2, Vietnam and China). The four sub-basins differ widely in population density (from 101 inhabitants km-2 in the upstream basins to more than 1000 inhabitants km-2 in the delta), land use, and agricultural practices. In terms of agricultural production, on the one hand, and consumption of food and feed on the other, the upstream sub-basins are autotrophic systems, exporting agricultural goods, while the delta is a heterotrophic system, depending on agricultural goods imports. The budget of the agricultural soils reveals great losses of nitrogen, mostly attributable to denitrification in rice paddy fields and of phosphorus, mostly caused by erosion. The budget of the drainage network shows high retention/elimination of nitrogen (from 62 to 77% in the upstream basins and 59% in the delta), and of phosphorus, with retention rates as high as 80% in the Da and Lo sub-basins which have large reservoirs in their downstream course (Hoa Binh on the Da and Thac Ba on the Lo). The total specific delivery estimated at the outlet of the whole Red River System is 855 kg km-2 yr-1 total N and 325 kg km-2 yr-1 total P. Nitrogen rather than phosphorus seems to be the potential limiting factor of algal growth in the plume of the Red River in Tonkin Bay.

Holocene evolution of the Liaohe Delta, a tide-dominated delta formed by multiple rivers in Northeast China

NASA Astrophysics Data System (ADS)

He, Lei; Xue, Chunting; Ye, Siyuan; Laws, Edward Allen; Yuan, Hongming; Yang, Shixiong; Du, Xiaolei

2018-02-01

The Liaohe Delta in Northeast China is one of the ecologically important estuarine deltas in China. It has been formed via the accumulation of sediment discharged by four rivers in the Liaohe Plain that enter Liaodong Bay. Twenty-seven 30-40 m long cores recovered from the Liaohe Plain and Liaodong Bay were analyzed for sedimentary characteristics, grain size, foraminifera species, and ages determined by accelerator mass spectrometry (AMS) 14C to document the stratigraphical sequence and the spatio-temporal evolution of the Liaohe Delta. Our results revealed that the sedimentary environments have evolved from fluvial, tidal flat/estuarine, to neritic and finally to a deltaic environment since the Late Pleistocene. The Holocene transgression arrived at the present coastline at ∼8500 cal a BP and flooded the maximum area of land at ∼7000 cal a BP. A deltaic environment prevailed in this area after 7000 cal a BP. Bounded by the modern Liaohe River mouth, the present deltaic sedimentary system can be divided into the eastern and western components. The rate of seaward progradation of the eastern paleocoastline was estimated to be ∼8.6 m/a since 7000 cal a BP; the eastern cores in the present coastline began receiving the deltaic sediments at ∼5000 cal a BP. The rate of seaward progradation of the western paleocoastline was estimated to be only ∼2.8 m/a since 7000 cal a BP. The coastline on the western side began accumulating deltaic sediments about 2000 years later than the eastern coastline. Depocenter shifting was hypothesized to be the reason for the spatial differences in the sedimentary processes. However, the change of sediment fluxes of the western rivers due to climate changes and ancient human impacts might be the reason for the differences of the temporal evolution of the eastern and western sedimentary systems in the Liaohe Delta.

Illicit drugs and their metabolites in 36 rivers that drain into the Bohai Sea and north Yellow Sea, north China.

PubMed

Wang, De-Gao; Zheng, Qiu-Da; Wang, Xiao-Ping; Du, Juan; Tian, Chong-Guo; Wang, Zhuang; Ge, Lin-Ke

2016-08-01

Illicit drugs and their metabolites have recently been recognized as an emerging group of contaminants due to their potential ecotoxicological impact in aquatic ecosystems. To date, information on the occurrence of these compounds in the aquatic environment of China remains limited. In this study, we collected surface water samples from 36 rivers in north China that discharge into the Bohai Sea and north Yellow Sea and measured the concentrations of amphetamine-like compounds, ketamines, cocainics, and opioids. The occurrence and spatial patterns of these substances show significant differences between the rivers and regions. Two designer drugs, methamphetamine (METH) and ketamine (KET), were the most abundant compounds detected in the entire set of samples (detection frequency of 92 and 69 %). The concentrations of METH and KET ranged from <0.1 to 42.0 ng L(-1) (mean = 4.53 ng L(-1)) and <0.05 to 4.50 ng L(-1) (mean = 0.49 ng L(-1)), respectively. The high detection frequencies of METH and KET are consistent with the fact that they are the main illicit drugs consumed in China. The high concentrations of these illicit drugs and their metabolites were found in areas that have a high population density. The riverine input of total illicit drugs into the Bohai Sea and north Yellow Sea was estimated to be in the range of 684 to 1160 kg per year.

Rapid development of microsatellite markers for the endangered fish Schizothorax biddulphi (Günther) using next generation sequencing and cross-species amplification.

PubMed

Luo, Wei; Nie, Zhulan; Zhan, Fanbin; Wei, Jie; Wang, Weimin; Gao, Zexia

2012-11-14

Tarim schizothoracin (Schizothorax biddulphi) is an endemic fish species native to the Tarim River system of Xinjiang and has been classified as an extremely endangered freshwater fish species in China. Here, we used a next generation sequencing platform (ion torrent PGM™) to obtain a large number of microsatellites for S. biddulphi, for the first time. A total of 40577 contigs were assembled, which contained 1379 SSRs. In these SSRs, the number of dinucleotide repeats were the most frequent (77.08%) and AC repeats were the most frequently occurring microsatellite, followed by AG, AAT and AT. Fifty loci were randomly selected for primer development; of these, 38 loci were successfully amplified and 29 loci were polymorphic across panels of 30 individuals. The H(o) ranged from 0.15 to 0.83, and H(e) ranged from 0.15 to 0.85, with 3.5 alleles per locus on average. Cross-species utility indicated that 20 of these markers were successfully amplified in a related, also an endangered fish species, S. irregularis. This study suggests that PGM™ sequencing is a rapid and cost-effective tool for developing microsatellite markers for non-model species and the developed microsatellite markers in this study would be useful in Schizothorax genetic analysis.

Dynamic reorganization of river basins.

PubMed

Willett, Sean D; McCoy, Scott W; Perron, J Taylor; Goren, Liran; Chen, Chia-Yu

2014-03-07

River networks evolve as migrating drainage divides reshape river basins and change network topology by capture of river channels. We demonstrate that a characteristic metric of river network geometry gauges the horizontal motion of drainage divides. Assessing this metric throughout a landscape maps the dynamic states of entire river networks, revealing diverse conditions: Drainage divides in the Loess Plateau of China appear stationary; the young topography of Taiwan has migrating divides driving adjustment of major basins; and rivers draining the ancient landscape of the southeastern United States are reorganizing in response to escarpment retreat and coastal advance. The ability to measure the dynamic reorganization of river basins presents opportunities to examine landscape-scale interactions among tectonics, erosion, and ecology.

Heavy Metal Pollution, Fractionation, and Potential Ecological Risks in Sediments from Lake Chaohu (Eastern China) and the Surrounding Rivers

PubMed Central

Zhang, Lei; Liao, Qianjiahua; Shao, Shiguang; Zhang, Nan; Shen, Qiushi; Liu, Cheng

2015-01-01

Heavy metal (Cr, Ni, Cu, Zn, Cd, and Pb) pollution, fractionation, and ecological risks in the sediments of Lake Chaohu (Eastern China), its eleven inflowing rivers and its only outflowing river were studied. An improved BCR (proposed by the European Community Bureau of Reference) sequential extraction procedure was applied to fractionate heavy metals within sediments, a geoaccumulation index was used to assess the extent of heavy metal pollution, and a risk assessment code was applied to evaluate potential ecological risks. Heavy metals in the Shuangqiao and Nanfei Rivers were generally higher than the other studied sites. Of the three Lake Chaohu sites, the highest concentrations were identified in western Chaohu. Heavy metal pollution and ecological risks in the lake’s only outflowing river were similar to those in the eastern region of the lake, to which the river is connected. Heavy metal concentrations occurred in the following order: Cd > Zn > Cu > Pb ≈ Ni ≈ Cr. Cr, Ni, and Cu made up the largest proportion of the residual fraction, while Cd was the most prominent metal in the exchangeable and carbonate-included fraction. Cd posed the greatest potential ecological risk; the heavy metals generally posed risks in the following order: Cd > Zn > Cu > Ni > Pb > Cr. PMID:26561822

[Spatiotemporal variation characteristics and related affecting factors of actual evapotranspiration in the Hun-Taizi River Basin, Northeast China].

PubMed

Feng, Xue; Cai, Yan-Cong; Guan, De-Xin; Jin, Chang-Jie; Wang, An-Zhi; Wu, Jia-Bing; Yuan, Feng-Hui

2014-10-01

Based on the meteorological and hydrological data from 1970 to 2006, the advection-aridity (AA) model with calibrated parameters was used to calculate evapotranspiration in the Hun-Taizi River Basin in Northeast China. The original parameter of the AA model was tuned according to the water balance method and then four subbasins were selected to validate. Spatiotemporal variation characteristics of evapotranspiration and related affecting factors were analyzed using the methods of linear trend analysis, moving average, kriging interpolation and sensitivity analysis. The results showed that the empirical parameter value of 0.75 of AA model was suitable for the Hun-Taizi River Basin with an error of 11.4%. In the Hun-Taizi River Basin, the average annual actual evapotranspiration was 347.4 mm, which had a slightly upward trend with a rate of 1.58 mm · (10 a(-1)), but did not change significantly. It also indicated that the annual actual evapotranspiration presented a single-peaked pattern and its peak value occurred in July; the evapotranspiration in summer was higher than in spring and autumn, and it was the smallest in winter. The annual average evapotranspiration showed a decreasing trend from the northwest to the southeast in the Hun-Taizi River Basin from 1970 to 2006 with minor differences. Net radiation was largely responsible for the change of actual evapotranspiration in the Hun-Taizi River Basin.

The response of drought in Beiluo River Basin of China based on the comprehensive method of Pa, SPI and fuzzy

NASA Astrophysics Data System (ADS)

Zhang, L. P.; Liu, D. F.; Zhang, H. X.; Huang, Q.; Chang, J. X.

2017-08-01

The meteorological drought is threatening the agricultural economic development with the change of the climate. In order to analyze the characteristics of drought spatiotemporal change, the precipitation data of eight meteorological stations in the Beiluo River Basin of Shaanxi Province of China have been collected, and the drought index of Pa, SPI and FSE have been selected to analyze the drought in Shaanxi Province for the last 55 years. The results of Pa, SPI and FSE test show that the droughts happened in the Beiluo River Basin are 149, 215 and 203 times in the past 55 years, respectively. Overall, the Beiluo River has a tendency to dry out. The main type of drought is low-grade drought, followed by the mediumgrade drought, and the specially-grade drought happened least. The average rainfall decreases in the Beiluo River Basin from the southeast to the northwest, and the change of the number of drought is just opposite to that of precipitation trend, which increases from southeast to northwest. The results will provide the scientific basis for the monitoring, evaluation, early warning and drought relief.

Modes, hydrodynamic processes and ecological impacts exerted by river-groundwater transformation in Junggar Basin, China

NASA Astrophysics Data System (ADS)

Wang, Wenke; Wang, Zhan; Hou, Rongzhe; Guan, Longyao; Dang, Yan; Zhang, Zaiyong; Wang, Hao; Duan, Lei; Wang, Zhoufeng

2018-05-01

The hydrodynamic processes and impacts exerted by river-groundwater transformation need to be studied at regional and catchment scale, especially with respect to diverse geology and lithology. This work adopted an integrated method to study four typical modes (characterized primarily by lithology, flow subsystems, and gaining/losing river status) and the associated hydrodynamic processes and ecological impacts in the southern part of Junggar Basin, China. River-groundwater transformation occurs one to four times along the basin route. For mode classification, such transformation occurs: once or twice, controlled by lithological factors (mode 1); twice, impacted by geomorphic features and lithological structures (mode 2); and three or four times, controlled by both geological and lithological structures (modes 3 and 4). Results also suggest: (1) there exist local and regional groundwater flow subsystems at 400 m depth, which form a multistage nested groundwater flow system. The groundwater flow velocities are 0.1-1.0 and <0.1 m/day for each of two subsystems; (2) the primary groundwater hydro-chemical type takes on apparent horizontal and vertical zoning characteristics, and the TDS of the groundwater evidently increases along the direction of groundwater flow, driven by hydrodynamic processes; (3) the streams, wetland and terminal lakes are the end-points of the local and regional groundwater flow systems. This work indicates that not only are groundwater and river water derived from the same source, but also hydrodynamic and hydro-chemical processes and ecological effects, as a whole in arid areas, are controlled by stream-groundwater transformation.

Geochemistry of the dissolved loads of the Liao River basin in northeast China under anthropogenic pressure: Chemical weathering and controlling factors

NASA Astrophysics Data System (ADS)

Ding, Hu; Liu, Cong-Qiang; Zhao, Zhi-Qi; Li, Si-Liang; Lang, Yun-Chao; Li, Xiao-Dong; Hu, Jian; Liu, Bao-Jian

2017-05-01

This study focuses on the chemical and Sr isotopic compositions of the dissolved load of the rivers in the Liao River basin, which is one of the principal river systems in northeast China. Water samples were collected from both the tributaries and the main channel of the Liao River, Daling River and Hun-Tai River. Chemical and isotopic analyses indicated that four major reservoirs (carbonates (+gypsum), silicates, evaporites and anthropogenic inputs) contribute to the total dissolved solutes. Other than carbonate (+gypsum) weathering, anthropogenic inputs provide the majority of the solutes in the river water. The estimated chemical weathering rates (as TDS) of silicate, carbonate (+gypsum) and evaporites are 0.28, 3.12 and 0.75 t/km2/yr for the main stream of the Liao River and 7.01, 25.0 and 2.80 t/km2/yr for the Daliao River, respectively. The associated CO2 consumption rates by silicate weathering and carbonate (+gypsum) weathering are 10.1 and 9.94 × 103 mol/km2/yr in the main stream of the Liao River and 69.0 and 80.4 × 103 mol/km2/yr in the Hun-Tai River, respectively. The Daling River basin has the highest silicate weathering rate (TDSsil, 3.84 t/km2/yr), and the Hun-Tai River has the highest carbonate weathering rate (TDScarb, 25.0 t/km2/yr). The Raoyang River, with an anthropogenic cation input fraction of up to 49%, has the lowest chemical weathering rates, which indicates that human impact is not a negligible parameter when studying the chemical weathering of these rivers. Both short-term and long-term study of riverine dissolved loads are needed to a better understanding of the chemical weathering and controlling factors.

A gradient analysis on urban sprawl and urban landscape pattern between 1985 and 2000 in the Pearl River Delta, China

NASA Astrophysics Data System (ADS)

Dai, Erfu; Wu, Zhuo; Du, Xiaodian

2017-04-01

Urbanization is an irreversible trend worldwide, especially in rapidly developing China. Accelerated urbanization has resulted in rapid urban sprawl and urban landscape pattern changes. Quantifying the spatiotemporal dynamics of urban land use and landscape pattern not only can reveal the characteristics of social transfer and economic development, but also can provide insights into the driving mechanisms of land use changes. In this study, we integrated remote sensing (RS), geographic information system (GIS), landscape metrics, and gradient analysis to quantitatively compare the spatiotemporal dynamics of land use, urban sprawl, and landscape pattern for nine cities in the Pearl River Delta from 1985‒2000. For the whole study region, urbanization was obvious. The results show an increase in urban buildup land and shrinkage of cropland in the Pearl River Delta. However, the nine cities differed greatly in terms of the process and magnitude of urban sprawl for both the spatial and temporal dimensions. This was most evident for the cities of Guangzhou and Shenzhen. Gradient analysis on urban landscape changes could deepen understanding of the stages of urban development and provide a scientific foundation for future urban planning and land management strategies in China.

Historical levels of heavy metals reconstructed from sedimentary record in the Hejiang River, located in a typical mining region of Southern China.

PubMed

Wang, Shaopeng; Wang, Yinghui; Zhang, Ruijie; Wang, Weitao; Xu, Daoquan; Guo, Jing; Li, Pingyang; Yu, Kefu

2015-11-01

Historical levels of Pb, Zn, Cd, Cr, Cu, Ni, As, Fe, Al and Mn were found in C1 and C2 sediment cores from the Hejiang River, which is located in a typical mining region of Southern China, the levels date back approximately 57 and 83 years. Temporal variations in the core C1 around the mining peaked in the 1960s, after which they exhibited a decreasing trend, which reflects successful government management. Historical events such as the Pacific War and China's first 5-year economic plan were recorded in core C2, which was collected from the downstream portion of the Hejiang River. Enrichment factors (EF), geo-accumulation (Igeo), and excess flux indicate that severe contamination occurred during the period between 1956 and 1985 due to the release of high amounts of mining waste from human activities around the core C1 region. The highest EF value was displayed by As (67); this was followed by Pb (64), Cd (39), and Zn (35). In contrast, the core C2 sediments exhibited minor pollution because of dilution from tributaries (the Fu River and the Daning River) that do not flow through the mined area and because C2 was farther from the source of the metals. The results of the risk assessment codes (RAC) for both cores indicate that Cd posed a high risk to the local environment. Principal component analysis (PCA) and correlation analysis (CA) revealed that accumulation of heavy metals was mainly due to mining pollution. Copyright © 2015. Published by Elsevier B.V.

Decline in suspended sediment concentration delivered by the Changjiang (Yangtze) River into the East China Sea between 1956 and 2013

NASA Astrophysics Data System (ADS)

Dai, Zhijun; Fagherazzi, Sergio; Mei, Xuefei; Gao, Jinjuan

2016-09-01

The temporal evolution of suspended sediment concentration (SSC) in a river debouching into the ocean provides vital insights into erosion processes in the watershed and dictates the evolution of the inner continental shelf. While the delivery of sediment from rivers to the ocean has received special attention in the recent past, few studies focused on the variability and dynamics of river SSC, especially in the Changjiang (Yangtze) river, China, the longest river in Asia. Here, variations in SSC delivered by the Changjiang River to the East China Sea and possible causes of its variability were detected based on a long-term time series of daily SSC and monthly water discharge measured at the Datong gauging station. The SSC data are further compared to a hydrological analysis of yearly precipitation covering the entire catchment. The results indicate the presence of a decline in SSC in the period 1956-2013, which can be divided into three phases: (i) high SSC (0.69 kg/m3) in the wet season and low SSC (0.2 kg/m3) in the dry season from 1956 to 1970; (ii) relative high SSC (0.58 kg/m3) in the wet season and low SSC (0.15 kg/m3) in the dry season from 1971 to 2002; and (iii) low SSC (0.19 kg/m3) in the wet season and very low SSC (0.09 kg/m3) in the dry season after 2002. These three periods have a mean yearly SSC values of 0.62, 0.42, and 0.18 kg/m3, respectively. Compared with 1956-1970, the slope of the rating curve between SSC and water discharge decreased, respectively, by 2% and 30% during the period 1971-2002 and 2002-2013. Soil erosion, dam construction, and banks reinforcement along the Changjiang River are the main causes of SSC variations. Fluctuations in water discharge are also controlling the SSC long-term variations. Specifically, from 1956 to 1970, the effect of soil erosion overrules that of dam impoundment, which is likely responsible for the high SSC; during the period 1970-2002, the influence of dam impoundment increases while that of soil erosion

Suggestions on water sources protection for the Gan River of Jiangxi, People's Republic of China

NASA Astrophysics Data System (ADS)

Fu, C.; Jiang, Z.

2007-05-01

The Gan River is the largest river in Jiangxi Province, which is located in the southeast of China and is the second branch of the Yangtze River. The Gan River flows through Jiangxi Province from the South to the North and plays an important role in the economic development for 14 counties or cities with a population of 22 million. Currently, there are 5 drinking water sources, such as the capital city, Nanchang, with a daily capacity of 0.72 million cubic meters. With the rapid economic development and increasing population in the Gan River basin, water pollution has become more serious. The water quality of the river has serious pollution on both side reaches and slight pollution on the middle reach. In the upstream, the main pollution problems come from the industrial wastewater and soil erosion, with industrial and sewage wastewater affecitng the downstream region. Based on the Provincial Environmental Quality Report of 2005, of 39 monitoring sections, the ones which reach a favorable rating of a National Standard are 71.8 per cent. The water quality in the upstream region had a good situation with 80 percent of locations meeting standards, but the water quality downstream of the capital city deteriorates and only 45.4 percent of this region can meet the standard. Standards are frequently exceeded for BOD5, TP, TN, fecal coliform, and petrolueum oil in the downstream portion. The industrial wastewater drained into the river was 139 million tons in 2005, of which Nanchang city is the largest contributor with 214 million tons of wastewater composed of 75 million tons of industrial wastewater and 139 million tons of domestic sewage. The largest COD contributor was from Ganzhou in the upstream of the river with a total of 83,800 tons in 2005. Currently, there are only two wastewater treatment facilities with daily treatment capacity of 402,000 tons along the river, which are located in the capital city. Some parameters in the treated water stil exceed the drainage

Using hydrodynamic model to predict PFOS and PFOA transport in the Daling River and its tributary, a heavily polluted river into the Bohai Sea, China.

PubMed

Li, Qifeng; Wang, Tieyu; Zhu, Zhaoyun; Meng, Jing; Wang, Pei; Suriyanarayanan, Sarvajayakesavalu; Zhang, Yueqing; Zhou, Yunqiao; Song, Shuai; Lu, Yonglong; Yvette, Baninla

2017-01-01

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are extremely persistent in the environment, and have the potential for long-range transport. The present study focused on the Daling River and its tributary, a larger river flowing into Liaodong Bay of the Bohai Sea. Recent studies have shown the elevated levels of PFOS and PFOA in the Daling River. Hence, the objective of this study was to investigate the seasonal changes, fate and transport modeling of PFOS and PFOA concentrations using one-dimensional DHI MIKE-11 river model. We designed three scenarios to assess the risk of PFOS and PFOA in surface water: the measured concentrations, constant maximum and the magnitude of a continuous constant load. The mean absolute errors divided by the mean of measured concentrations were 41-64% for PFOS and 29-36% for PFOA. The result indicated that PFOS and PFOA in the downstream of the Daling River would not reach a harmful level with the current load. The fluorochemical parks contributed an average of 44.57% of the total PFOS and 95.44% of the total PFOA flow that reached the estuary. The mass flow was observed as 1.74 kg y -1 for PFOS and 40.57 kg y -1 for PFOA to the Bohai Sea. These modeling results may be useful for monitoring the status and trends of emerging POPs and will help the determination of the risk to both humans and wildlife, in the estuarine and coastal areas of the Bohai Sea, China. Copyright © 2016 Elsevier Ltd. All rights reserved.

How to allocate water resources under climate change in the arid endorheic river basin, Northwest China

NASA Astrophysics Data System (ADS)

Zhang, A.; Feng, D.; Tian, Y.; Zheng, Y.

2017-12-01

Water resource is of fundamental importance to the society and ecosystem in arid endorheic river basins, and water-use conflicts between upstream and downstream are usually significant. Heihe river basin (HRB) is the second largest endorheic river basin in china, which is featured with dry climate, intensively irrigated farmlands in oases and significant surface water-groundwater interaction. The irrigation districts in the middle HRB consume a large portion of the river flow, and the low HRB, mainly Gobi Desert, has an extremely vulnerable ecological environment. The water resources management has significantly altered the hydrological processes in HRB, and is now facing multiple challenges, including decline of groundwater table in the middle HRB, insufficient environmental flow for the lower HRB. Furthermore, future climate change adds substantial uncertainty to the water system. Thus, it is imperative to have a sustainable water resources management in HRB in order to tackle the existing challenges and future uncertainty. Climate projection form a dynamical downscaled climate change scenario shows precipitation will increase at a rate of approximately 3 millimeter per ten years and temperature will increase at a rate of approximately 0.2 centigrade degree per ten years in the following 50 years in the HRB. Based on an integrated ecohydrological model, we evaluated how the climate change and agricultural development would collaboratively impact the water resources and ecological health in the middle and lower HRB, and investigated how the water management should cope with the complex impact.

Atmospheric deposition of PBDEs and DPs in Dongjiang River Basin, South China.

PubMed

Wu, Xiaowei; Wang, Yan; Hou, Minmin; Luo, Chunling; Zhao, Hongxia; Zhang, Gan

2017-02-01

The atmospheric deposition fluxes of polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DPs) in Dongjiang River Basin of the Pearl River Delta in South China were investigated during winter and summer, respectively. The total deposition fluxes varied from 4.74 to 27.0 ng/m 2 /day for PBDEs and 8.77 to 206 ng/m 2 /day for DPs, respectively. The fractions of anti-DP to the total DPs (f anti ) varied from 0.28 to 0.63 (mean = 0.43 ± 0.06), i.e., generally lower than those in commercial products, which might be attributed to the different environmental fates of the two isomers. Significant seasonal and spatial variations of PBDEs and DPs were observed. The deposition fluxes in summer were generally higher than those in winter, which may be due to the relatively high temperature and rainfall in summer under the influence of prevailing subtropical monsoon climate. Moreover, high deposition fluxes of PBDEs and DPs in urban areas and significant urban/rural gradient implied that local industrial activities in the urban areas were primary sources, which were further confirmed by the results of principal component analysis. The highest deposition of PBDE and DP fluxes was found at different sampling sites, suggesting PBDEs and DPs may be derived from different industries or products.

Modern Pearl River Delta and Permian Huainan coalfield, China: A comparative sedimentary facies study

USGS Publications Warehouse

Suping, P.; Flores, R.M.

1996-01-01

Sedimentary facies types of the Pleistocene deposits of the Modern Pearl River Delta in Guangdong Province, China and Permian Member D deposits in Huainan coalfield in Anhui Province are exemplified by depositional facies of anastomosing fluvial systems. In both study areas, sand/sandstone and mud/mudstone-dominated facies types formed in diverging and converging, coeval fluvial channels laterally juxtaposed with floodplains containing ponds, lakes, and topogenous mires. The mires accumulated thin to thick peat/coal deposits that vary in vertical and lateral distribution between the two study areas. This difference is probably due to attendant sedimentary processes that affected the floodplain environments. The ancestral floodplains of the Modern Pearl River Delta were reworked by combined fluvial and tidal and estuarine processes. In contrast, the floodplains of the Permian Member D were mainly influenced by freshwater fluvial processes. In addition, the thick, laterally extensive coal zones of the Permian Member D may have formed in topogenous mires that developed on abandoned courses of anastomosing fluvial systems. This is typified by Seam 13-1, which is a blanket-like body that thickens to as much as 8 in but also splits into thinner beds. This seam overlies deposits of diverging and converging, coeval fluvial channels of the Sandstone D, and associated overbank-floodplain deposits. The limited areal extent of lenticular Pleistocene peat deposits of the Modern Pearl River Delta is due to their primary accumulation in topogenous mires in the central floodplains that were restricted by contemporaneous anastomosing channels.

The Perspective of Riverbank Filtration in China

NASA Astrophysics Data System (ADS)

Li, J.; Teng, Y.; Zhai, Y.; Zuo, R.

2014-12-01

Sustainable drinking water supply can affect the health of people, and the surrounding ecosystems. According to statistics of the monitoring program of drinking water sources in 309 at or above prefecture level of China in 2013, the major pollutants index were total phosphorus, ammonia and manganese in surface drinking water sources, respectively, iron, ammonia and manganese in groundwater drinking water sources, respectively. More than 150 drinking water emergency environmental accidents happened since 2006, 52 of these accidents led to the disruption of water supply in waterworks, and a population of over ten million were affected. It indicated that there is a potential risk for people's health by the use of river water directly and it is necessary to require alternative techniques such as riverbank filtration for improving the drinking water quality. Riverbank filtration is an inexpensive natural process, not only smoothing out normal pollutant concentration found in surface water but also significantly reducing the risk from such emergency events as chemical spill into the river. Riverbank filtration technique has been used in many countries more than 100 years, including China. In China, in 1950s, the bank infiltration technique was first applied in northeast of China. Extensive bank infiltration application was conducted in 1980s, and more than 300 drinking water sources utilities bank infiltration established mainly near the Songhua River Basin, the Yellow River Basin, Haihe River Basin. However, the comparative lack of application and researches on riverbank filtration have formed critical scientific data gap in China. As the performance of riverbank filtration technique depend on not only the design and setting such as well type, pumping rate, but also the local hydrogeology and environmental properties. We recommend more riverbank filtration project and studies to be conducted to collect related significant environmental geology data in China

Identifying the hydrochemical characteristics of rivers and groundwater by multivariate statistical analysis in the Sanjiang Plain, China

NASA Astrophysics Data System (ADS)

Cao, Yingjie; Tang, Changyuan; Song, Xianfang; Liu, Changming; Zhang, Yinghua

2016-06-01

Two multivariate statistical technologies, factor analysis (FA) and discriminant analysis (DA), are applied to study the river and groundwater hydrochemistry and its controlling processes in the Sanjiang Plain of the northeast China. Factor analysis identifies five factors which account for 79.65 % of the total variance in the dataset. Four factors bearing specific meanings as the river and groundwater hydrochemistry controlling processes are divided into two groups, the "natural hydrochemistry evolution" group and the "pollution" group. The "natural hydrochemistry evolution" group includes the salinity factor (factor 1) caused by rock weathering and the residence time factor (factor 2) reflecting the groundwater traveling time. The "pollution" group represents the groundwater quality deterioration due to geogenic pollution caused by elevated Fe and Mn (factor 3) and elevated nitrate (NO3 -) introduced by human activities such as agriculture exploitations (factor 5). The hydrochemical difference and hydraulic connection among rivers (surface water, SW), shallow groundwater (SG) and deep groundwater (DG) group are evaluated by the factor scores obtained from FA and DA (Fisher's method). It is showed that the river water is characterized as low salinity and slight pollution, and the shallow groundwater has the highest salinity and severe pollution. The SW is well separated from SG and DG by Fisher's discriminant function, but the SG and DG can not be well separated showing their hydrochemical similarities, and emphasize hydraulic connections between SG and DG.

An Enhanced K-Means Algorithm for Water Quality Analysis of The Haihe River in China.

PubMed

Zou, Hui; Zou, Zhihong; Wang, Xiaojing

2015-11-12

The increase and the complexity of data caused by the uncertain environment is today's reality. In order to identify water quality effectively and reliably, this paper presents a modified fast clustering algorithm for water quality analysis. The algorithm has adopted a varying weights K-means cluster algorithm to analyze water monitoring data. The varying weights scheme was the best weighting indicator selected by a modified indicator weight self-adjustment algorithm based on K-means, which is named MIWAS-K-means. The new clustering algorithm avoids the margin of the iteration not being calculated in some cases. With the fast clustering analysis, we can identify the quality of water samples. The algorithm is applied in water quality analysis of the Haihe River (China) data obtained by the monitoring network over a period of eight years (2006-2013) with four indicators at seven different sites (2078 samples). Both the theoretical and simulated results demonstrate that the algorithm is efficient and reliable for water quality analysis of the Haihe River. In addition, the algorithm can be applied to more complex data matrices with high dimensionality.

Trace Elements in Dominant Species of the Fenghe River, China: Their Relations to Environmental Factors.

PubMed

Yang, Yang; Zhou, Zhengchao; Bai, Yanying; Jiao, Wentao; Chen, Weiping

2016-07-01

The distribution of trace elements (TEs) in water, sediment, riparian soil and dominant plants was investigated in the Fenghe River, Northwestern China. The Fenghe River ecosystem was polluted with Cd, Cr, Hg and Pb. There was a high pollution risk in the midstream and downstream regions and the risk level for Cd was much higher than that of the other elements. The average values of bioconcentration coefficient for Cd and Zn were 2.21 and 1.75, respectively, indicating a large accumulation of Cd and Zn in the studied species. With broad ecological amplitudes, L. Levl. et Vant. Trin., and L. had the greatest TE concentrations in aboveground and belowground biomass of the studied species and were potential biomonitors or phytoremediators for the study area. Multivariate techniques including cluster analysis, correlation analysis, principal component analysis, and canonical correspondence analysis were used to analyze the relations between TE concentrations in plants and various environmental factors. The soil element concentration is the main factor determining the accumulation of TEs in plants. The co-release behavior of common pollutants and TEs drove the accumulation of Hg, Cd, and As in the studied plants. Significant enrichment of some elements in the Fenghe River has led to a decline in the biodiversity of plants. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Urban Household Carbon Emission and Contributing Factors in the Yangtze River Delta, China

PubMed Central

Xu, Xibao; Tan, Yan; Chen, Shuang; Yang, Guishan; Su, Weizhong

2015-01-01

Carbon reduction at the household level is an integral part of carbon mitigation. This study analyses the characteristics, effects, contributing factors and policies for urban household carbon emissions in the Yangtze River Delta of China. Primary data was collected through structured questionnaire surveys in three cities in the region – Nanjing, Ningbo, and Changzhou in 2011. The survey data was first used to estimate the magnitude of household carbon emissions in different urban contexts. It then examined how, and to what extent, each set of demographic, economic, behavioral/cognitive and spatial factors influence carbon emissions at the household level. The average of urban household carbon emissions in the region was estimated to be 5.96 tonnes CO2 in 2010. Energy consumption, daily commuting, garbage disposal and long-distance travel accounted for 51.2%, 21.3%, 16.0% and 11.5% of the total emission, respectively. Regulating rapidly growing car-holdings of urban households, stabilizing population growth, and transiting residents’ low-carbon awareness to household behavior in energy saving and other spheres of consumption in the context of rapid population aging and the growing middle income class are suggested as critical measures for carbon mitigation among urban households in the Yangtze River Delta. PMID:25884853

Characteristics and source identification of dissolved trace elements in the Jinshui River of the South Qinling Mts., China.

PubMed

Bu, Hongmei; Wang, Weibo; Song, Xianfang; Zhang, Quanfa

2015-09-01

Dissolved trace elements and physiochemical parameters were analyzed to investigate their physicochemical characteristics and identify their sources at 12 sampling sites of the Jinshui River in the South Qinling Mts., China from October 2006 to November 2008. The two-factor ANOVA indicated significant temporal variations of the dissolved Cu, Fe, Sr, Si, and V (p < 0.001 or p < 0.05). With the exception of Sr (p < 0.001), no significant spatial variations were found. Distributions and concentrations of the dissolved trace elements displayed that dissolved Cu, Fe, Sr, Si, V, and Cr were originated from chemical weathering and leaching from the soil and bedrock. Dissolved Cu, Fe, Sr, As, and Si were also from anthropogenic inputs (farming and domestic effluents). Correlation and regression analysis showed that the chemical and physical processes of dissolved Cu was influenced by water temperature and dissolved oxygen (DO) to some degree. Dissolved Fe and Sr were affected by colloid destabilization or sedimentary inputs. Concentrations of dissolved Si were slightly controlled by biological uptake. Principal component analysis confirmed that Fe, Sr, and V resulted from domestic effluents, agricultural runoff, and confluence, whereas As, Cu, and Si were from agricultural activities, and Cr and Zn through natural processes. The research results provide a reference for ecological restoration and protection of the river environment in the Qinling Mts., China.

Sequencing Insights into Microbial Communities in the Water and Sediments of Fenghe River, China.

PubMed

Lu, Sidan; Sun, Yujiao; Zhao, Xuan; Wang, Lei; Ding, Aizhong; Zhao, Xiaohui

2016-07-01

The connection between microbial community structure and spatial variation and pollution in river waters has been widely investigated. However, water and sediments together have rarely been explored. In this study, Illumina high-throughput sequencing was performed to analyze microbes in 24 water and sediment samples from natural to anthropogenic sources and from headstream to downstream areas. These data were used to assess variability in microbial community structure and diversity along in the Fenghe River, China. The relationship between bacterial diversity and environmental parameters was statistically analyzed. An average of 1682 operational taxonomic units was obtained. Microbial diversity increased from the headstream to downstream and tended to be greater in sediment compared with water. The water samples near the headstream endured relatively low Shannon and Chao1 indices. These diversity indices and the number of observed species in the water and sediment samples increase downstream. The parameters also differ in the two river tributaries. Community structures shift based on the extent of nitrogen pollution variation in the sediment and water samples. The four most dominant genera in the water community were Escherichia, Acinetobacter, Comamonadaceae, and Pseudomonas. In the sediments, the most dominant genera were Stramenopiles, Flavobacterium, Pseudomonas, and Comamonadaceae. The number of ammonia-oxidizing archaea in the headstream water slightly differed from that in the sediment but varied considerably in the downstream sediments. Statistical analysis showed that community variation is correlated with changes in ammonia nitrogen, total nitrogen, and nitrate nitrogen. This study identified different microbial community structures in river water and sediments. Overall this study emphasized the need to elucidate spatial variations in bacterial diversity in water and sediments associated with physicochemical gradients and to show the effects of such

Walled Sedimentary Basins of China: Perpetrators or Victims of Plateau Growth?

NASA Astrophysics Data System (ADS)

Carroll, A. R.; Graham, S. A.; Smith, M. E.

2004-12-01

Western China and adjacent areas of central Asia are characterized by low relief, internally drained sedimentary basins that are divided by actively uplifting mountain ranges. The margins of these basins often show evidence for extensive contractional deformation, yet their interiors are surprisingly stable. Basins such as the Tarim and Junggar also exhibit long and apparently continuous histories of closed drainage in the same approximate location (over 250 my in the case of Junggar). In contrast to traditional foreland basins, these basins are not uniquely associated with a specific thrust belt, nor do they show evidence for underlying decollements. We therefore propose the new term "walled basin", in recognition of the essential role of peripheral orogenic walls in creating and maintaining closed drainage and impounding sediments. Walled basins in Asia currently are restricted to areas that receive less than 40 cm/yr precipitation, suggesting that aridity plays a role in preventing fluvial breach of the basin walls (cf., Sobel et al., 2003). Entrapment of sediment within the closed Qaidam basin in the northeast Tibetan plateau has been implicated as a potential mechanism of plateau growth, based on the observations that the basin retains mass within the orogen and creates level topography. However, we propose that the Qaidam instead represents a walled basin that has been elevated due to underplating of the plateau, and is fated to eventual destruction as deformation continues. Several lines of reasoning support this conclusion. First, DEM analysis shows that modern drainage divides for the Qaidam and other walled basins never rise more than 1-2 km above the basin floors, limiting the amount of possible topgraphic infill. Second, the Tarim and Junggar basins presently remain well below 2000 m and probably have never been higher, despite receiving large influxes of detritus from adjacent ranges. Third, the Qaidam basin, like the Tarim and Junggar basins, has an

Occurrence and ecological risk assessment of emerging organic chemicals in urban rivers: Guangzhou as a case study in China.

PubMed

Peng, Feng-Jiao; Pan, Chang-Gui; Zhang, Min; Zhang, Nai-Sheng; Windfeld, Ronja; Salvito, Daniel; Selck, Henriette; Van den Brink, Paul J; Ying, Guang-Guo

2017-07-01

Urban rivers may receive contamination from various sources including point sources like domestic sewage and nonpoint sources (e.g., runoff), resulting in contamination with various chemicals. This study investigated the occurrence of emerging organic contaminants (3 endocrine disrupting compounds (EDCs), and 17 pharmaceuticals and personal care products (PPCPs)) in six urban rivers of a representative subtropical city, Guangzhou (southern China). Our results showed that EDCs and personal care products were frequently detected in the water phase and sediment phase. 4-nonylphenol (4-NP) was the most predominant compound with the highest concentration of 5050ng/L in the water phase and 14,400ng/g dry weight (dw) in the sediment. Generally, higher total concentrations of EDCs and PPCPs were detected in the four urban streams compared to the main stream Zhujiang River and the Liuxi River at the suburb area. A screening-level risk assessment showed that 4-nonylphenol and triclosan (TCS) pose potential risks to aquatic organisms in most sampling sites. For individual taxa, 4-NP may pose risks to various groups of aquatic organisms, while TCS only might pose high risks to algae. Higher contamination of EDCs and PPCPs was observed in rivers in urban area; 4-nonylphenol and triclosan showed RQs>1 in >70% of the reported area. Copyright © 2017 Elsevier B.V. All rights reserved.

Urban rivers as hotspots of regional nitrogen pollution.

PubMed

Zhang, Xiaohong; Wu, Yiyun; Gu, Baojing

2015-10-01

Excess nitrogen inputs to terrestrial ecosystems via human activities have deteriorated water qualities on regional scales. Urban areas as settlements of over half global population, however, were usually not considered in the analysis of regional water pollution. Here, we used a 72-month monitoring data of water qualities in Hangzhou, China to test the role of urban rives in regional nitrogen pollution and how they response to the changes of human activities. Concentrations of ammonium nitrogen in urban rivers were 3-5 times higher than that in regional rivers. Urban rivers have become pools of reactive nitrogen and hotspots of regional pollution. Moreover, this river pollution is not being measured by current surface water monitoring networks that are designed to measure broader regional patterns, resulting in an underestimation of regional pollution. This is crucial to urban environment not only in China, but also in other countries, where urban rivers are seriously polluted. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aquatic environmental changes and anthropogenic activities reflected by the sedimentary records of the Shima River, Southern China.

PubMed

Gao, Lei; Wang, Zhuowei; Shan, Jiju; Chen, Jianyao; Tang, Changyuan; Yi, Ming

2017-05-01

Reconstructing historical sedimentary records is essential for better understanding the effects of anthropogenic activities on river environments. We used lead-210 to date riverine sediment core from the Shima River in China. We obtained a sedimentary history of 34 years (1982-2015) for core S2, which had a length of 34 cm. The sedimentation rate of 0.304-2.04 cm y -1 was controlled by both flood events and anthropogenic activities. The conservative element content depth profiles remained relatively constant, suggestive of a relatively stable sediment provenance; therefore, the increase in the sedimentation rate over time was mainly the result of domestic and industrial wastewater effluent and the construction of a rubber dam at the middle and lower reach of the Shima River. From 1982 to 2015, the nutrient and trace metal depth profiles could be divided in three periods based on their trends. From 1982 to 1993, the vertical profiles of nutrients (organic carbon, total phosphorus, and total nitrogen) and three trace metals (nickel, zinc, and manganese) were relatively stable; however, the gradual decrease in copper and cadmium was likely associated with a reduction in agricultural chemical application. From 1993 to 2003, a population explosion and rapid industrialization were responsible for an increase in the input of pollutants into the Shima River, which was partly attenuated by water from the Dong River, leading to a gradual increase in nutrient and trace metal contents. Finally, from 2003 to 2015, the Shima River stopped being used as a source of water due to its deteriorating water quality. The relatively lower velocity of the water flow after the recovery of its flow direction and the reconstruction of the rubber dam in 2009 provided advantageous sedimentary conditions, promoting nutrient accumulation and significant trace metal enrichment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sulfate migration in a river affected by acid mine drainage from the Dabaoshan mining area, South China.

PubMed

Chen, Meiqin; Lu, Guining; Guo, Chuling; Yang, Chengfang; Wu, Jingxiong; Huang, Weilin; Yee, Nathan; Dang, Zhi

2015-01-01

Sulfate, a major component of acid mine drainage (AMD), its migration in an AMD-affected river which located at the Dabaoshan mine area of South China was investigated to pursue the remediation strategy. The existing factors of relatively low pH values of 2.8-3.9, high concentrations of SO4(2-) (∼1940 mg L(-1)) and Fe(3+) (∼112 mg L(-1)) facilitated the precipitation of schwertmannite (Fe8O8(OH)6SO4·nH2O) in the upstream river. Geochemical model calculations implied the river waters were supersaturated, creating the potential for precipitation of iron oxyhydroxides. These minerals evolved from schwertmannite to goethite with the increasing pH from 2.8 to 5.8 along the river. The concentration of heavy metals in river waters was great reduced as a result of precipitation effects. The large size of the exchangeable sulfate pool suggested that the sediments had a strong capacity to bind SO4(2-). The XRD results indicated that schwertmannite was the predominant form of sulfate-bearing mineral phases, which was likely to act as a major sulfate sink by incorporating water-borne sulfate into its internal structure and adsorbing it onto its surface. The small size of reduced sulfur pools and strong oxidative status in the surface sediments further showed that SO4(2-) shifting from water to sediment in form of sulfate reduction was not activated. In short, precipitation of sulfate-rich iron oxyhydroxides and subsequent SO4(2-) adsorption on these minerals as well as water dilution contributed to the attenuation of SO4(2-) along the river waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microplastics in Freshwater River Sediments in Shanghai, China: A Case Study of Risk Assessment in Mega Cities

NASA Astrophysics Data System (ADS)

Peng, G.; Xu, P.

2017-12-01

Microplastics are plastics that measure less than 5 mm, which attracted exponential interest in recent years. Microplastics are widely distributed in water, sediments, and biotas. Most of distribution studies focus on the marine environment, yet methods to conduct risk assessment are limited. Widespread of microplastics has raised alarm for the well-being of marine living resources because of its negative ecological effects that has been proved. To understand the distribution of microplastics in urban rivers and source of marine microplastics, we investigated into river sediments in Shanghai, the biggest city in China. Seven sampling sites covered most of city central districts including one sampling site from a tidal flat. Density separation, microscopic inspection and identification were conducted to analyze microplastic abundance, shape and color. It is found that pellets were the most prevalent shape, followed by fiber and fragment. White microplastics were the most common type in terms of color. White foamed microplastic pellets were widely distributed in urban river sediments. Microplastic abundance from rivers was one to two orders of magnitude higher than that from the tidal flat. The significant difference between river and tidal flat samples lead to the conclusion that coastal rivers may be the source of microplastics, therefore in situ data and legitimate estimation should be considered by policy-makers. Seven types of microplastics were identified by μ-FT-IR analysis, indicating a secondary source. Comparison between two types of μ-FT-IR instruments was summarized. Framework for environmental risk assessment for microplastics in sediments was proposed. Indicators and ranks were select for the assessment of microplastic in sediments. It is recommended to select the index, integrate statistical data, follow expert opinions extensively and construct comprehensive evaluation method and ecological risk assessment system for the Chinese context.

Spatial heterogeneity of stream environmental conditions and macroinvertebrates community in an agriculture dominated watershed and management implications for a large river (the Liao River, China) basin.

PubMed

Gao, Xin; Niu, Cuijuan; Chen, Yushun; Yin, Xuwang

2014-04-01

Understanding the effects of watershed land uses (e.g., agriculture, urban industry) on stream ecological conditions is important for the management of large river basins. A total of 41 and 56 stream sites (from first to fourth order) that were under a gradient of watershed land uses were monitored in 2009 and 2010, respectively, in the Liao River Basin, Northeast China. The monitoring results showed that a total of 192 taxa belonging to four phyla, seven classes, 21 orders and 91 families were identified. The composition of macroinvertebrate community in the Liao River Basin was dominated by aquatic insect taxa (Ephemeroptera and Diptera), Oligochaeta and Molluscs. The functional feeding group GC (Gatherer/Collector) was dominant in the whole basin. Statistical results showed that sites with less watershed impacts (lower order sites) were characterized by higher current velocity and habitat score, more sensitive taxa (e.g., Ephemeroptera), and the substrate was dominated by high percentage of cobble and pebble. The sites with more impacts from agriculture and urban industry (higher order sites) were characterized by higher biochemical (BOD5) and chemical oxygen demand (COD), more tolerant taxa (e.g., Chironominae), and the substrate was dominated by silt and sand. Agriculture and urban-industry activities have reduced habitat condition, increased organic pollutants, reduced macroinvertebrate abundance, diversity, and sensitive taxa in streams of the lower Liao River Basin. Restoration of degraded habitat condition and control of watershed organic pollutants could be potential management priorities for the Basin.

More frequent flooding? Changes in flood frequency in the Pearl River basin, China, since 1951 and over the past 1000 years

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Shi, Peijun; Sun, Peng

2018-05-01

Flood risks across the Pearl River basin, China, were evaluated using a peak flood flow dataset covering a period of 1951-2014 from 78 stations and historical flood records of the past 1000 years. The generalized extreme value (GEV) model and the kernel estimation method were used to evaluate frequencies and risks of hazardous flood events. Results indicated that (1) no abrupt changes or significant trends could be detected in peak flood flow series at most of the stations, and only 16 out of 78 stations exhibited significant peak flood flow changes with change points around 1990. Peak flood flow in the West River basin increased and significant increasing trends were identified during 1981-2010; decreasing peak flood flow was found in coastal regions and significant trends were observed during 1951-2014 and 1966-2014. (2) The largest three flood events were found to cluster in both space and time. Generally, basin-scale flood hazards can be expected in the West and North River basins. (3) The occurrence rate of floods increased in the middle Pearl River basin but decreased in the lower Pearl River basin. However, hazardous flood events were observed in the middle and lower Pearl River basin, and this is particularly true for the past 100 years. However, precipitation extremes were subject to moderate variations and human activities, such as building of levees, channelization of river systems, and rapid urbanization; these were the factors behind the amplification of floods in the middle and lower Pearl River basin, posing serious challenges for developing measures of mitigation of flood hazards in the lower Pearl River basin, particularly the Pearl River Delta (PRD) region.

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in sediments from the Yellow and Yangtze Rivers, China.

PubMed

Gao, Lirong; Huang, Huiting; Liu, Lidan; Li, Cheng; Zhou, Xin; Xia, Dan

2015-12-01

Polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are toxic environmental pollutants that are often found in sediments. The Yangtze and Yellow rivers in China are two of the largest rivers in Asia and are therefore important aquatic ecosystems; however, few studies have investigated the PCDD/F and PCB content in the sediments of these rivers. Accordingly, this study was conducted to generate baseline data for future environmental risk assessments. In the present study, 26 surface sediments from the middle reaches of the Yellow and Yangtze rivers were analyzed for PCDD/Fs and dioxin-like (dl) PCBs by high-resolution gas chromatography and high-resolution mass spectrometry. The ranges of PCDD/F, dl-PCB, and WHO-TEQ content in sediments from the Yellow River were 2.1-19.8, 1.11-9.9, and 0.08-0.57 pg/g (dry weight), respectively. The ranges of PCDD/F, dl-PCB, and WHO-TEQ content in sediments from the Yangtze River were 6.1-84.9, 1.8-24.1, and 0.13-0.29 pg/g (dry weight), respectively. Total organic carbon and dl-PCB contents in the Yellow River were significantly correlated (Spearman's correlation coefficient, r = 0.64, P < 0.05). It is well known that total organic carbon plays a role in the transport and redistribution of dl-PCB. Principal component analysis indicated that PCDD/Fs may arise from pentachlorophenol, sodium pentachlorophenate, and atmospheric deposition, while dl-PCBs likely originate from burning of coal and wood for domestic heating. The dioxin levels in the river sediments examined in this study were relatively low. These findings advance our knowledge regarding eco-toxicity and provide useful information regarding contamination sources.

Contamination and ecological risk assessment of toxic trace elements in the Xi River, an urban river of Shenyang city, China.

PubMed

Lin, Chunye; He, Mengchang; Liu, Xitao; Guo, Wei; Liu, Shaoqing

2013-05-01

The objectives of this study were to assess the enrichment, contamination, and ecological risk posed by toxic trace elements in the sediments of the Xi River in the industrialized city of Shenyang, China. Surface sediment and sediment core were collected; analyzed for toxic trace elements; and assessed with an index of geoaccumulation (Igeo), enrichment factor (EF) value, potential ecological risk factor (Er), ecological risk index (RI), and probable effect concentration quotient (PECQ). Elemental concentrations (milligram per kilogram) were 8.5-637.9 for As, 6.5-103.9 for Cd, 12.2-21.9 for Co, 90.6-516.0 for Cr, 258.1-1,791.5 for Cu, 2.6-19.0 for Hg, 70.5-174.5 for Ni, 126.9-1,405.8 for Pb, 3.7-260.0 for Sb, 38.4-100.4 for V, and 503-4,929 for Zn. The Igeo, EF, Er, and PECQ indices showed that the contamination of Cd and Hg was more serious than that of As, Cr, Cu, Ni, Pb, Sb, and Zn, whereas the presence of Co and V might be primarily from natural sources. The Igeo index for Cr and Ni might underestimate the degree of contamination, potentially as a result of high concentrations of these elements in the shale. The RI index was higher than 600, indicating a notably high ecological risk of sediment for the river. The average PECQ for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn ranged from 1.4 to 4.1 for surface sediment and from 5.2 to 9.6 in the sediment cores, indicating a high potential for an adverse biological effect. It was concluded that the sediment in the Xi River was severely contaminated and should be remediated as a hazardous material.

Potential relationships between the river discharge and the precipitation in the Jinsha River basin, China

NASA Astrophysics Data System (ADS)

Wang, Gaoxu; Zeng, Xiaofan; Zhao, Na; He, Qifang; Bai, Yiran; Zhang, Ruoyu

2018-02-01

The relationships between the river discharge and the precipitation in the Jinsha River basin are discussed in this study. In addition, the future precipitation trend from 2011-2050 and its potential influence on the river discharge are analysed by applying the CCLM-modelled precipitation. According to the observed river discharge and precipitation, the annual river discharge at the two main hydrological stations displays good correlations with the annual precipitation in the Jinsha River basin. The predicted future precipitation tends to change similarly as the change that occurred during the observation period, whereas the monthly distributions over a year could be more uneven, which is unfavourable for water resources management.

Is ENSO related to 2015 Easter Star Capsized on the Yangtze River of China?

NASA Astrophysics Data System (ADS)

Xie, P.

2015-12-01

Natural disasters have profound effects on community security and economic damage of China's Hubei province. In June 1st, 2015, a cruise ship, Easter Star, capsized on Yangtze River in Hubei province with 442 died. What reason gives rise to such strong convection causing ship sunk? Based on the wind disasters of Hubei province happened in 1963-2015, this study analyzes their features bytime-series regression, and correlates them to global El Niño/Southern Oscillation (ENSO) events. The compared results demonstrated that the wind disasters shown an increasing tendency. There are two peaks corresponding to the strongest ENSO peaks during the past 50 years; each peak lasts two-three years. The facts demonstrated an essential linear relation between the ENSO phenomena and wind disasters in Hubei province. 2015 Easter Star capsized happened at current El Niño event in 2014-2015. We also observed that the historical wind disasters appeared in seasonal variation. Over 90% events concentrated in spring and summer; very few events happened in autumn and winter. Moreover, the disasters depend on the geographic conditions. Most disasters concentrated in four zones, named as Xingshan-Baokang, Xuanen, Wufeng-Yichang, Jingzhou-Gongan, in which Xingshan and Changyang are the two most density of zones. Yangtze River provides an air flowing conduct for strong convective winds. It can be concluded that the strong convection causing 2015 Easter Star capsized is related to current global ENSO phenomenon.Keywords: ENSO, wind disaster, time-series regression analysis, Easter Star, Yangtze River, Hubei Province,

Changes and Relationships of Climatic and Hydrological Droughts in the Jialing River Basin, China.

PubMed

Zeng, Xiaofan; Zhao, Na; Sun, Huaiwei; Ye, Lei; Zhai, Jianqing

2015-01-01

The comprehensive assessment of climatic and hydrological droughts in terms of their temporal and spatial evolutions is very important for water resources management and social development in the basin scale. To study the spatial and temporal changes of climatic and hydrological droughts and the relationships between them, the SPEI and SDI are adopted to assess the changes and the correlations of climatic and hydrological droughts by selecting the Jialing River basin, China as the research area. The SPEI and SDI at different time scales are assessed both at the entire Jialing River basin and at the regional levels of the three sub basins. The results show that the SPEI and SDI are very suitable for assessing the changes and relationships of climatic and hydrological droughts in large basins. Based on the assessment, for the Jialing River basin, climatic and hydrological droughts have the increasing tendency during recent several decades, and the increasing trend of climatic droughts is significant or extremely significant in the western and northern basin, while hydrological drought has a less significant increasing trend. Additionally, climatic and hydrological droughts tend to increase in the next few years. The results also show that on short time scales, climatic droughts have one or two months lag impact on hydrological droughts in the north-west area of the basin, and have one month lag impact in south-east area of the basin. The assessment of climatic and hydrological droughts based on the SPEI and SDI could be very useful for water resources management and climate change adaptation at large basin scale.

Changes and Relationships of Climatic and Hydrological Droughts in the Jialing River Basin, China

PubMed Central

Zeng, Xiaofan; Zhao, Na; Sun, Huaiwei; Ye, Lei; Zhai, Jianqing

2015-01-01

The comprehensive assessment of climatic and hydrological droughts in terms of their temporal and spatial evolutions is very important for water resources management and social development in the basin scale. To study the spatial and temporal changes of climatic and hydrological droughts and the relationships between them, the SPEI and SDI are adopted to assess the changes and the correlations of climatic and hydrological droughts by selecting the Jialing River basin, China as the research area. The SPEI and SDI at different time scales are assessed both at the entire Jialing River basin and at the regional levels of the three sub basins. The results show that the SPEI and SDI are very suitable for assessing the changes and relationships of climatic and hydrological droughts in large basins. Based on the assessment, for the Jialing River basin, climatic and hydrological droughts have the increasing tendency during recent several decades, and the increasing trend of climatic droughts is significant or extremely significant in the western and northern basin, while hydrological drought has a less significant increasing trend. Additionally, climatic and hydrological droughts tend to increase in the next few years. The results also show that on short time scales, climatic droughts have one or two months lag impact on hydrological droughts in the north-west area of the basin, and have one month lag impact in south-east area of the basin. The assessment of climatic and hydrological droughts based on the SPEI and SDI could be very useful for water resources management and climate change adaptation at large basin scale. PMID:26544070

Ecological status classification of the Taizi River Basin, China: a comparison of integrated risk assessment approaches.

PubMed

Fan, Juntao; Semenzin, Elena; Meng, Wei; Giubilato, Elisa; Zhang, Yuan; Critto, Andrea; Zabeo, Alex; Zhou, Yun; Ding, Sen; Wan, Jun; He, Mengchang; Lin, Chunye

2015-10-01

Integrated risk assessment approaches allow to achieve a sound evaluation of ecological status of river basins and to gain knowledge about the likely causes of impairment, useful for informing and supporting the decision-making process. In this paper, the integrated risk assessment (IRA) methodology developed in the EU MODELKEY project (and implemented in the MODELKEY Decision Support System) is applied to the Taizi River (China), in order to assess its Ecological and Chemical Status according to EU Water Framework Directive (WFD) requirements. The available dataset is derived by an extensive survey carried out in 2009 and 2010 across the Taizi River catchment, including the monitoring of physico-chemical (i.e. DO, EC, NH3-_N, chemical oxygen demand (COD), biological oxygen demand in 5 days (BOD5) and TP), chemical (i.e. polycyclic aromatic hydrocarbons (PAHs) and metals), biological (i.e. macroinvertebrates, fish, and algae), and hydromorphological parameters (i.e. water quantity, channel change and morphology diversity). The results show a negative trend in the ecological status from the highland to the lowland of the Taizi River Basin. Organic pollution from agriculture and domestic sources (i.e. COD and BOD5), unstable hydrological regime (i.e. water quantity shortage) and chemical pollutants from industry (i.e. PAHs and metals) are found to be the main stressors impacting the ecological status of the Taizi River Basin. The comparison between the results of the IRA methodology and those of a previous study (Leigh et al. 2012) indicates that the selection of indicators and integrating methodologies can have a relevant impact on the classification of the ecological status. The IRA methodology, which integrates information from five lines of evidence (i.e., biology, physico-chemistry, chemistry, ecotoxicology and hydromorphology) required by WFD, allows to better identify the biological communities that are potentially at risk and the stressors that are most

WRF model for precipitation simulation and its application in real-time flood forecasting in the Jinshajiang River Basin, China

NASA Astrophysics Data System (ADS)

Zhou, Jianzhong; Zhang, Hairong; Zhang, Jianyun; Zeng, Xiaofan; Ye, Lei; Liu, Yi; Tayyab, Muhammad; Chen, Yufan

2017-07-01

An accurate flood forecasting with long lead time can be of great value for flood prevention and utilization. This paper develops a one-way coupled hydro-meteorological modeling system consisting of the mesoscale numerical weather model Weather Research and Forecasting (WRF) model and the Chinese Xinanjiang hydrological model to extend flood forecasting lead time in the Jinshajiang River Basin, which is the largest hydropower base in China. Focusing on four typical precipitation events includes: first, the combinations and mode structures of parameterization schemes of WRF suitable for simulating precipitation in the Jinshajiang River Basin were investigated. Then, the Xinanjiang model was established after calibration and validation to make up the hydro-meteorological system. It was found that the selection of the cloud microphysics scheme and boundary layer scheme has a great impact on precipitation simulation, and only a proper combination of the two schemes could yield accurate simulation effects in the Jinshajiang River Basin and the hydro-meteorological system can provide instructive flood forecasts with long lead time. On the whole, the one-way coupled hydro-meteorological model could be used for precipitation simulation and flood prediction in the Jinshajiang River Basin because of its relatively high precision and long lead time.

Coastal environmental monitoring using remotely sensed data and GIS techniques in the Modern Yellow River delta, China.

PubMed

Zhang, Yang

2011-08-01

On the basis of remote sensing and GIS techniques, the Landsat data obtained in 1987, 1996, and 2008 were used to examine coastline changes in the Modern Yellow River (MYR) delta in China. The coastal land lost and gained illustrations were derived, the rates of coastal change were estimated, and the coastal parts that experienced severe changes were identified. The results revealed that the accretion rates in the MYR delta coast has been decelerating while the accretion effect remained. Taken the artificial coast from the south of ShenXianGou (SXG) to Gudong Oil Field (GOF) as the landmark, the coast in the south of the landmark showed an accretion pattern, while the coast in the west of the landmark showed an erosion pattern. Wherein, the coast from Chao River Estuary (CRE) to Zhuang 106 (Z106) showed an erosion pattern with the transition from erosion to accretion and the accelerated rates from east to west. The coast from Z106 to the south border of GOF also showed erosion pattern but significant differences existed among the internal coastal parts. The coast from the south border of GOF to XiaoDao River Estuary (XDRE) showed a pattern from rapid accretion to dynamic balance of accretion/erosion, and the trend towards erosion. The coast from XDRE to XiaoQing River Estuary (XQRE) showed slow accretion pattern. Human activities have heavily influenced the natural evolution of the MYR delta coast.

Spatio-temporal variational characteristics analysis of heavy metals pollution in water of the typical northern rivers, China

NASA Astrophysics Data System (ADS)

Lu, Hongwei; Yu, Sen

2018-04-01

The rapid urbanization and industrialization in developing countries have increased pollution by heavy metals, which is a concern for human health and the environment. In this study, according to the data obtained from the monitoring stations in the Songhua River basin, the multivariate statistical analysis methods are applied to the hydrological data of the Songhua River basin in order to examine the relation between human activities and the spatio-temporal change of heavy metals (Pb and Cu) in water. By comparing the concentrations at different flow periods, the minimum Pb concentrations are found to have occurred most frequently in low flow periods while the maximum values mostly appeared in average flow periods. Moreover, the minimum Cu concentration in the water frequently occurred in high flow periods. The results show there are low Pb and Cu concentrations in upstream and downstream sections and high concentrations in mid-stream sections, and high concentrations are most frequently measured in the sections of Ashihe' downstream and estuary. Moreover, we have predicted the future (during 2018-2025) trend of the change for the heavy metals pollution in the rivers. The results demonstrated intense human activities are the most important factor causing jump features of typical heavy metal pollution in the different periods for different sections of this study area. The research would provide decision-making and planning for the Songhua River basin during the period of China's 13th Five-Year Plan.

Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China

PubMed Central

Gong, Yao; Yu, Zhigang; Yao, Qingzhen; Chen, Hongtao; Mi, Tiezhu; Tan, Jiaqiang

2015-01-01

The rapid growth of the economy in China has caused dramatic growth in the industrial and agricultural development in the Yellow River (YR) watershed. The hydrology of the YR has changed dramatically due to the climate changes and water management practices, which have resulted in a great variation in the fluxes of riverine nutrients carried by the YR. To study these changes dissolved nutrients in the YR were measured monthly at Lijin station in the downstream region of the YR from 2002 to 2004. This study provides detailed information on the nutrient status for the relevant studies in the lower YR and the Bohai Sea. The YR was enriched in nitrate (average 314 μmol·L−1) with a lower concentration of dissolved silicate (average 131 μmol·L−1) and relatively low dissolved phosphate (average 0.35 μmol·L−1). Nutrient concentrations exhibited substantial seasonal and yearly variations. The annual fluxes of dissolved inorganic nitrogen, phosphate, and silicate in 2004 were 5.3, 2.5, and 4.2 times those in 2002, respectively, primarily due to the increase in river discharge. The relative contributions of nutrient inputs to nitrogen in the YR were: wastewater > fertilizer > atmospheric deposition > soil; while to phosphorus were: wastewater > fertilizer > soil > atmospheric deposition. The ratios of N, P and Si suggest that the YR at Lijin is strongly P-limited with respect to potential phytoplankton growth. PMID:26287226

Air Stagnations for China (1985-2014): Climatological Mean Features and Trends

NASA Astrophysics Data System (ADS)

Huang, Qianqian; Cai, Xuhui; Song, Yu; Zhu, Tong

2017-04-01

Air stagnation is an important meteorological measurement for unfavourable air pollution conditions, but little is known about it in China. We conducted a comprehensive investigation of air stagnation in China, based on sounding and surface observations of 81 stations, from January 1985 to December 2014. The stagnation criteria were revised to be topographically dependent for the great physical diversity in this country. It is found that the annual mean air stagnation occurrences are closely related to general topography and climate features. Two basins in the northwest and southwest of China—Tarim and Sichuan Basins—exhibit the most frequent stagnation occurrence (50% days per year), whereas two plateaus (Tibet-Qinghai and Inner Mongolia Plateau) and the east coastal areas experience the least (20% days per year). Over the whole country, air stagnations achieve maxima in summer and minima in winter, except for Urumqi, a major city in the northwest of China, where stagnations keep a rather constant value yearly around with a minimum in spring. There is a nationwide positive trend in stagnation occurrence during 1985-2014, with the strongest increasing centres over Shandong Peninsula in eastern China and the south of Shaanxi in central China. Dependence degrees of air stagnations on three components (upper- and lower-air winds, precipitation-free days) are examined. It shows that the spatial distribution and trend of air stagnations are mainly driven by the behaviours of upper-air wind speeds. Air stagnation climatology presents a specific view to the natural background of atmosphere features being responsible to air pollution levels. The results presented in this paper may have significant implication to air pollution research, and may be used in atmospheric environment management or air pollution control.

High aerosol load over the Pearl River Delta, China, observed with Raman lidar and Sun photometer

NASA Astrophysics Data System (ADS)

Ansmann, Albert; Engelmann, Ronny; Althausen, Dietrich; Wandinger, Ulla; Hu, Min; Zhang, Yuanghang; He, Qianshan

2005-07-01

Height-resolved data of the particle optical properties, the vertical extend of the haze layer, aerosol stratification, and the diurnal cycle of vertical mixing over the Pearl River Delta in southern China are presented. The observations were performed with Raman lidar and Sun photometer at Xinken (22.6°N, 113.6°E) near the south coast of China throughout October 2004. The lidar run almost full time on 21 days. Sun photometer data were taken on 23 days, from about 0800 to 1700 local time. The particle optical depth (at about 533-nm wavelength) ranged from 0.3-1.7 and was, on average, 0.92. Ångström exponents varied from 0.65-1.35 (for wavelengths 380 to 502 nm) and from 0.75-1.6 (for 502 to 1044 nm), mean values were 0.97 and 1.22. The haze-layer mean extinction-to-backscatter ratio ranged from 35-59 sr, and was, on average, 46.7 sr. The top of the haze layer reached to heights of 1.5-3 km in most cases.

Games between stakeholders and the payment for ecological services: evidence from the Wuxijiang River reservoir area in China

PubMed Central

2018-01-01

A gambling or “game” phenomenon can be observed in the complex relationship between sources and receptors of ecological compensation among multiple stakeholders. This paper investigates the problem of gambling to determine payment amounts, and details a method to estimate the ecological compensation amount related to water resources in the Wuxijiang River reservoir area in China. Public statistics and first-hand data obtained from a field investigation were used as data sources. Estimation of the source and receptor amount of ecological compensation relevant to the water resource being investigated was achieved using the contingent valuation method (CVM). The ecological compensation object and its benefit and gambling for the Wuxijiang River water source area are also analyzed in this paper. According to the results of a CVM survey, the ecological compensation standard for the Wuxijiang River was determined by the CVM, and the amount of compensation was estimated. Fifteen blocks downstream of the Wuxijiang River and 12 blocks in the water source area were used as samples to administer a survey that estimated the willingness to pay (WTP) and the willingness to accept (WTA) the ecological compensation of Wuxijiang River for both nonparametric and parametric estimation. Finally, the theoretical value of the ecological compensation amount was estimated. Without taking other factors into account, the WTP of residents in the Wuxi River water source was 297.48 yuan per year, while the WTAs were 3864.48 yuan per year. The theoretical standard of ecological compensation is 2294.39–2993.81 yuan per year. Under the parameter estimation of other factors, the WTP of residents in the Wuxi River water source area was 528.72 yuan per year, while the WTA was 1514.04 yuan per year. The theoretical standard of ecological compensation is 4076.25–5434.99 yuan per year. The main factors influencing the WTP ecological compensation in the Wuxi River basin are annual income and age

Games between stakeholders and the payment for ecological services: evidence from the Wuxijiang River reservoir area in China.

PubMed

Shu, Lin

2018-01-01

A gambling or "game" phenomenon can be observed in the complex relationship between sources and receptors of ecological compensation among multiple stakeholders. This paper investigates the problem of gambling to determine payment amounts, and details a method to estimate the ecological compensation amount related to water resources in the Wuxijiang River reservoir area in China. Public statistics and first-hand data obtained from a field investigation were used as data sources. Estimation of the source and receptor amount of ecological compensation relevant to the water resource being investigated was achieved using the contingent valuation method (CVM). The ecological compensation object and its benefit and gambling for the Wuxijiang River water source area are also analyzed in this paper. According to the results of a CVM survey, the ecological compensation standard for the Wuxijiang River was determined by the CVM, and the amount of compensation was estimated. Fifteen blocks downstream of the Wuxijiang River and 12 blocks in the water source area were used as samples to administer a survey that estimated the willingness to pay (WTP) and the willingness to accept (WTA) the ecological compensation of Wuxijiang River for both nonparametric and parametric estimation. Finally, the theoretical value of the ecological compensation amount was estimated. Without taking other factors into account, the WTP of residents in the Wuxi River water source was 297.48 yuan per year, while the WTAs were 3864.48 yuan per year. The theoretical standard of ecological compensation is 2294.39-2993.81 yuan per year. Under the parameter estimation of other factors, the WTP of residents in the Wuxi River water source area was 528.72 yuan per year, while the WTA was 1514.04 yuan per year. The theoretical standard of ecological compensation is 4076.25-5434.99 yuan per year. The main factors influencing the WTP ecological compensation in the Wuxi River basin are annual income and age. The

Distribution and potential ecological risk of 50 phenolic compounds in three rivers in Tianjin, China.

PubMed

Zhong, Wenjue; Wang, Donghong; Wang, Zijian

2018-04-01

Phenolic compounds widely exist in the surface water of many countries; however, few studies have simultaneously analyzed and evaluated broad-spectrum phenolic compounds in various components of the water environment. Therefore this study analyzed the distribution and potential ecological risk of 50 phenolic compounds in the surface water, sediment and suspended particulate matter of three important rivers in Tianjin, the main heavy industry city with high pollution in China. The qualitative results show that phenolic pollution existed extensively in the three rivers and the kinds of phenolic compounds in the water were relatively higher than in both sediment and suspended particulate matter. The quantitative results show that the phenolic pollution in the wet-season samples was serious than dry-season samples. Meanwhile, total concentrations of phenolic compounds in three components from the Dagu Drainage River (DDR) were all much higher than those in the Beitang Drainage River (BDR) and Yongdingxin River (YDXR). The highest total concentrations of phenolic compounds in three components all appeared in wet-season samples in DDR, and the highest total concentration was 1354 μg/L in surface water, 719 μg/kg dw in suspended particulate matter and 2937 μg/kg dw in sediment, respectively. The ecological risk of phenolic compounds in surface water was evaluated using the quotient method, and phenolic compounds with risk quotient (RQ) > 1 (RQ > 0.3 for YDXR) were identified as priority pollutants. Five kinds of phenolic compounds were identified as priority phenolic compounds in BDR, and the order of risk was 2-cresol > 2,4-xylenol > 2-sec-butylphenol > 2-naphthol > 3-cresol. Six kinds of phenolic compounds were identified as priority phenolic compounds in DDR, and the order of risk was 2-naphthol > p-chloro-m-xylenol > 4-cresol > 3-cresol > 2,4-xylenol > 2,3,6-Trimethylphenol. In YDXR, only phenol, 2-naphthol and 2,4-xylenol were identified as

Preliminary results of water quality assessment using phytoplankton and physicochemical approaches in the Huai River Basin, China.

PubMed

Chen, Hao; Zuo, Qi-Ting; Zhang, Yong-Yong

2017-11-01

Water pollution has been a significant issue in the Huai River Basin (HRB) of China since the late 1970s. In July and December 2013, two field investigations were carried out at 10 sites along the main streams of the basin. The monitoring indices contained both physicochemical variables and the structure and composition of phytoplankton communities. The correlations between communities and physicochemical variables were analyzed using cluster analysis and redundancy analysis. Moreover, water quality was evaluated using the comprehensive nutrition state index (TLI) and Shannon-Wiener diversity index (H). Results indicated that more phytoplankton species were present in December than in July, but total density was less in December. Phytoplankton communities in the midstream of the Shaying River were affected by the same physicochemical factors throughout the year, but ammonia nitrogen and total phosphorus had the greatest influence on these sites in July and December, respectively. The water pollution status of the sampling sites was much greater in the Shaying River midstream than at other sites. TLI was more suitable than H for assessing water quality in the study area. These results provide valuable information for policy makers and stakeholders in water quality assessment, water ecosystem restoration, and sustainable basin management in the HRB.

Studies on kinetics of water quality factors to establish water transparency model in Neijiang River, China.

PubMed

Li, Ronghui; Pan, Wei; Guo, Jinchuan; Pang, Yong; Wu, Jianqiang; Li, Yiping; Pan, Baozhu; Ji, Yong; Ding, Ling

2014-05-01

The basis for submerged plant restoration in surface water is to research the complicated dynamic mechanism of water transparency. In this paper, through the impact factor analysis of water transparency, the suspended sediment, dissolved organic matter, algae were determined as three main impactfactors for water transparency of Neijiang River in Eastern China. And the multiple regression equation of water transparency and sediment concentration, permanganate index, chlorophyll-a concentration was developed. Considering the complicated transport and transformation of suspended sediment, dissolved organic matter and algae, numerical model of them were developed respectively for simulating the dynamic process. Water transparency numerical model was finally developed by coupling the sediment, water quality, and algae model. These results showed that suspended sediment was a key factor influencing water transparency of Neijiang River, the influence of water quality indicated by chemical oxygen demand and algal concentration indicated by chlorophyll a were indeterminate when their concentrations were lower, the influence was more obvious when high concentrations are available, such three factors showed direct influence on water transparency.

Occurrence and distribution of antibiotics, antibiotic resistance genes in the urban rivers in Beijing, China.

PubMed

Xu, Yan; Guo, Changsheng; Luo, Yi; Lv, Jiapei; Zhang, Yuan; Lin, Haixia; Wang, Li; Xu, Jian

2016-06-01

The occurrence and distribution of sulfonamide and tetracycline, corresponding bacterial resistant rate and resistance genes (ARGs) and two integrase genes were investigated in seven urban rivers in Beijing, China. The total concentration of sulfonamide and tetracycline ranged from 1.3 × 10(1)-1.5 × 10(3) ng/L and 3.9 × 10(1)-5.4 × 10(4) ng/L for water, and 1.0 × 10(0)-2.7 × 10(2) and 3.1 × 10(1)-1.6 × 10(2) ng/g for sediment, respectively. The sul resistant rate was 2-3 times higher than tet resistant rate in both surface water and sediment. The average rate of sul resistance and tet resistance were up to 81.3% and 38.6% in surface water, 89.1% and 69.4% in the sediment, respectively. The sul1, tetA and tetE genes were predominant in term of the absolute abundance. The absolute abundance of ARGs in Wenyu River and Qinghe River, which were close to the direct discharging sites, were 5-50 times higher than those in the other investigated urban rivers, suggesting that the source release played an important role in the distribution of ARGs. The sul1 and sul2 genes had positive correlation (p < 0.05) with sulfonamides, and the tet resistance genes was significantly correlated with tetracyclines (p < 0.05), indicating that some ARGs and antibiotics in the urban rivers had identical sources of pollution. Considering principal component analysis, sampling sites (QH5, QH6, B1, B2, B3 and BX2) intimated that a complex interplay of processes govern fate and transport of ARGs in the junction of rivers. These results are significant to understand the fate, and the contribution of ARGs from the source release. In view of the large-scale investigation of urban rivers system in Beijing, it reflected the bacterial resistance in sewage drainage system. Such investigation highlights the management on controlling the pollutant release which was seemed as a major driving force for the maintenance and propagation of many ARGs during the development of

Factor analysis and cluster analysis applied to assess the water quality of middle and lower Han River in Central China

NASA Astrophysics Data System (ADS)

Kuo, Yi-Ming; Liu, Wen-Wen

2015-04-01

The Han River basin is one of the most important industrial and grain production bases in the central China. A lot of factories and towns have been established along the river where large farmlands are located nearby. In the last few decades the water quality of the Han River, specifically in middle and lower reaches, has gradually declined. The agricultural nonpoint pollution and municipal and industrial point pollution significantly degrade the water quality of the Han River. Factor analysis can be applied to reduce the dimensionality of a data set consisting of a large number of inter-related variables. Cluster analysis can classify the samples according to their similar characters. In this study, factor analysis is used to identify major pollution indicators, and cluster analysis is employed to classify the samples based on the sample locations and hydrochemical variables. Water samples were collected from 12 sample sites collected from Xiangyang City (middle Han River) to Wuhan City (lower Han River). Correlations among 25 hydrochemical variables are statistically examined. The important pollutants are determined by factor analysis. A three-factor model is determined and explains over 85% of the total river water quality variation. Factor 1, including SS, Chl-a, TN and TP, can be considered as the nonpoint source pollution. Factor 2, including Cl-, Br-, SO42-, Ca2+, Mg2+, K+, Fe2+ and PO43-, can be treated as the industrial pollutant pollution. Factor 3, including F- and NO3-, reflects the influence of the groundwater or self-purification capability of the river water. The various land uses along the Han River correlate well with the pollution types. In addition, the result showed that the water quality of Han River deteriorated gradually from middle to lower Han River. Some tributaries have been seriously polluted and significantly influence the mainstream water quality of the Han River. Finally, the result showed that the nonpoint pollution and the point

Occurrence and Ecological Risk Assessment of Eight Endocrine-Disrupting Chemicals in Urban River Water and Sediments of South China.

PubMed

Huang, Cong; Wu, Liu-Hong; Liu, Guo-Qiang; Shi, Lei; Guo, Ying

2018-05-03

Chemicals in the water of urban areas are representative of the occurrence of these chemicals in the city surrounding water systems and reflect recent human or industrial usage of those chemicals in the sampling areas. In this study, the levels of eight endocrine-disrupting chemicals [including bisphenol analogues, parabens, and triclosan (TCS)] were determined in urban river water and sediments in Guangzhou, South China, and their related ecological risks were evaluated. The eight target chemicals were frequently detected in our samples, with concentrations ranging from not detected (ND) to 65,600 ng/L and from ND to 492 ng/g dw in river water and sediments, respectively. Among these chemicals, the three most abundant were bisphenol A (BPA) (accounting for 35% of the total amount), methyl paraben (MeP) (23%), and TCS (14%) in river water and BPA (43%), TCS (37%), and MeP (14%) in sediments. Significant correlations were found between most target EDCs, particularly MeP and TCS, in river water and sediments (both p < 0.01), indicating their similar sources and wide usage. The ecological risk assessment methods used suggested that TCS was the chemical of primary concern, with an average hazard quotient (HQ) = 1.57 (up to 11.5) in river water and an average HQ = 0.74 (up to 3.63) in sediments. In addition, the ecological risk assessment of different sampling sites indicated a suspected high-risk level for some sites in the study area.

Ecotoxicological bioassays of sediment leachates in a river bed flanked by decommissioned pesticide plants in Nantong City, East China.

PubMed

Zhou, Yan; Wang, Fenghe; Wan, Jinzhong; He, Jian; Li, Qun; Qiang Chen; Gao, Jay; Lin, Yusuo; Zhang, Shengtian

2017-03-01

Traditionally, the toxicity of river contaminants is analyzed chemically or physically through river bed sediments. The biotoxicity of polluted sediment leachates has not caught our attention. This study aims to overcome this deficiency through a battery of biotests which were conducted to monitor comprehensive toxicity of sediment leachates for the Yaogang River in East Jiangsu Province of China, which is in close proximity to former pesticide plants. The general physical and chemical parameters of major pollutants were analyzed from river bed sediments collected at five strategic locations. The ecotoxicity analyses undertaken include overall fish (adult zebrafish) acute toxicity, luminescent bacteria (Vibrio fischeri) bioassay, and zebrafish embryo toxicity assay. Compared with the control group, sediment leachates increased the lethality, inhibited the embryos hatching and induced development abnormalities of zebrafish embryos, and inhibited the luminescence of V. fischeri. The results show that sediment leachates may assume various toxic effects, depending on the test organism. This diverse toxicity to aquatic organisms reflects their different sensitivity to sediment leachates. It is found clearly that V. fischeri was the organism which was characterized by the highest sensitivity to the sediment leachates. The complicated toxicity of leachates was not caused by one single factor but by multiple pollutants together. This indicates the need of estimations of sediment leachate not only taking into account chemical detection but also of applying the biotests to the problem. Thus, multigroup bioassays are necessary to realistically evaluate river ecological risks imposed by leachates.

An Enhanced K-Means Algorithm for Water Quality Analysis of The Haihe River in China

PubMed Central

Zou, Hui; Zou, Zhihong; Wang, Xiaojing

2015-01-01

The increase and the complexity of data caused by the uncertain environment is today’s reality. In order to identify water quality effectively and reliably, this paper presents a modified fast clustering algorithm for water quality analysis. The algorithm has adopted a varying weights K-means cluster algorithm to analyze water monitoring data. The varying weights scheme was the best weighting indicator selected by a modified indicator weight self-adjustment algorithm based on K-means, which is named MIWAS-K-means. The new clustering algorithm avoids the margin of the iteration not being calculated in some cases. With the fast clustering analysis, we can identify the quality of water samples. The algorithm is applied in water quality analysis of the Haihe River (China) data obtained by the monitoring network over a period of eight years (2006–2013) with four indicators at seven different sites (2078 samples). Both the theoretical and simulated results demonstrate that the algorithm is efficient and reliable for water quality analysis of the Haihe River. In addition, the algorithm can be applied to more complex data matrices with high dimensionality. PMID:26569283

Inorganic aerosols responses to emission changes in Yangtze River Delta, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Xinyi; Li, Juan; Fu, Joshua S.

2014-05-15

China announced the Chinese National Ambient Air Quality standards (CH-NAAQS) on Feb. 29th, 2012, and PM2.5 is for the very first time included in the standards as a criteria pollutant. In order to probe into PM2.5 pollution over Yangtze River Delta, which is one of the major urban clusters hosting more than 80 million people in China, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Both simulation and observation demonstrated that, inorganic aerosols have substantial contributions to PM2.5 overmore » YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3-) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3-concentration throughout the year. We also found that in winter NO3- was even increased under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4+) and sulfate (SO42-), while other seasons showed decrease response of NO3-. Sensitivity responses of NO3- under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3- formation was actually VOC sensitive due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols.« less

Phenomena and characteristics of barrier river reaches in the middle and lower Yangtze River, China

NASA Astrophysics Data System (ADS)

You, Xingying; Tang, Jinwu

2017-06-01

Alluvial river self-adjustment describes the mechanism whereby a river that was originally in an equilibrium state of sediment transport encounters some disturbance that destroys the balance and results in responses such as riverbed deformation. A systematic study of historical and recent aerial photographs and topographic maps in the Middle and Lower Reaches of the Yangtze River (MLYR) shows that river self-adjustment has the distinguishing feature of transferring from upstream to downstream, which may affect flood safety, waterway morphology, bank stability, and aquatic environmental safety over relatively long reaches downstream. As a result, it is necessary to take measures to control or block this transfer. Using the relationship of the occurrence time of channel adjustments between the upstream and downstream, 34 single-thread river reaches in the MLYR were classified into four types: corresponding, basically corresponding, basically not corresponding, not corresponding. The latter two types, because of their ability to prevent upstream channel adjustment from transferring downstream, are called barrier river reaches in this study. Statistics indicate that barrier river reaches are generally single thread and slightly curved, with a narrow and deep cross-sectional morphology, and without flow deflecting nodes in the upper and middle parts of reaches. Moreover, in the MLYR, barrier river reaches have a hydrogeometric coefficient of {<}{4}, a gradient {>}1.2‱, a silty clay content of the concave bank {>}{9.5}%, and a median diameter of the bed sediment {>}{0.158} mm. The barrier river reach mechanism lies in that can effectively centralise the planimetric position of the main stream from different upstream directions, meaning that no matter how the upper channel adjusts, the main stream shows little change, providing relatively stable inflow conditions for the lower reaches. Regarding river regulation, it is necessary to optimise the benefits of barrier river

Microplastics in oysters Saccostrea cucullata along the Pearl River Estuary, China.

PubMed

Li, Heng-Xiang; Ma, Li-Sha; Lin, Lang; Ni, Zhi-Xin; Xu, Xiang-Rong; Shi, Hua-Hong; Yan, Yan; Zheng, Guang-Ming; Rittschof, Daniel

2018-05-01

As a transitional zone between riverine and marine environments, an estuary plays an important role for the sources, accumulation and transport of microplastics. Although estuarine environments are hotspots of microplastic pollution, the correlation between microplastic pollution and aquatic organisms is less known. Here we investigated microplastic pollution in wild oysters Saccostrea cucullata from 11 sampling sites along the Pearl River Estuary in South China. The microplastic abundances in oysters ranged from 1.4 to 7.0 items per individual or from 1.5 to 7.2 items per gram tissue wet weight, which were positively related to those in surrounding waters. The oysters near urban areas contained significantly more microplastics than those near rural areas. Fibers accounted for 69.4% of the total microplastics in oysters. Microplastic sizes varied from 20 to 5000 μm and 83.9% of which were less than 100 μm. Light color microplastics were significantly more common than dark color ones. Based on the results, oysters are recommended as a biomonitor for the microplastic pollution in estuaries. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development and validation of a bacteria-based index of biotic integrity for assessing the ecological status of urban rivers: A case study of Qinhuai River basin in Nanjing, China.

PubMed

Li, Jie; Li, Yi; Qian, Bao; Niu, Lihua; Zhang, Wenlong; Cai, Wei; Wu, Hainan; Wang, Peifang; Wang, Chao

2017-07-01

With the increasing human disturbance to urban rivers, the extinction and biodiversity losses of some macroorganism species decreased the accuracy of bioassessment. In this study, a novel index of biotic integrity based on bacteria (Ba-IBI) was first developed for Qinhuai River in Nanjing city, China. Thirty-two biofilm samples were collected along the river bank and the bacterial communities were identified by high-throughput sequencing. By the range, responsive, and redundancy tests, four core metrics were selected from the dataset of 78 candidate metrics, including Pielou's evenness index, proportion of Paenibacillus, proportion of OTUs tolerant to organic pollution and proportion of Nitrosomonas. The results showed that the Ba-IBI was able to effectively discriminate different impaired site groups, and had a good correlation with the index of water quality (r = 0.79, p < 0.01) and the qualitative habitat evaluation index (r = 0.51, p < 0.01). Moreover, the Ba-IBI was negatively correlated with the number of population within a 1 km buffer (r = -0.71, p < 0.01). Application of the index showed that most of the sites were in the poor or bad class in the river. Our study revealed that the Ba-IBI is an effective and reliable approach for assessing the ecological status of Qinhuai River basin, which can complement the existing ecological assessment approaches for urban rivers. Meanwhile, repeted surveys and field validations are still needed to further improve the applicability of the index in future studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spectral reflectance properties of major objects in desert oasis: a case study of the Weigan-Kuqa river delta oasis in Xinjiang, China.

PubMed

Zhang, Fei; Tiyip, Tashpolat; Ding, Jianli; Sawut, Mamat; Tashpolat, Nigara; Kung, Hsiangte; Han, Guihong; Gui, Dongwei

2012-08-01

Aiming at the remote sensing application has been increasingly relying on ground object spectral characteristics. In order to further research the spectral reflectance characteristics in arid area, this study was performed in the typical delta oasis of Weigan and Kuqa rivers located north of Tarim Basin. Data were collected from geo-targets at multiple sites in various field conditions. The spectra data were collected for different soil types including saline-alkaline soil, silt sandy soil, cotton field, and others; vegetations of Alhagi sparsifolia, Phragmites australis, Tamarix, Halostachys caspica, etc., and water bodies. Next, the data were processed to remove high-frequency noise, and the spectral curves were smoothed with the moving average method. The derivative spectrum was generated after eliminating environmental background noise so that to distinguish the original overlap spectra. After continuum removal of the undesirable absorbance, the spectrum curves were able to highlight features for both optical absorbance and reflectance. The spectrum information of each ground object is essential for fully utilizing the multispectrum data generated by remote sensing, which will need a representative spectral library. In this study using ENVI 4.5 software, a preliminary spectral library of surface features was constructed using the data surveyed in the study area. This library can support remote sensing activities such as feature investigation, vegetation classification, and environmental monitoring in the delta oasis region. Future plan will focus on sharing and standardizing the criteria of professional spectral library and to expand and promote the utilization of the spectral databases.

Contrasting Distributions of Bacterial Branched Tetraethers along a Soil-River-Lake Transect in the Arid Region of Northwestern China

NASA Astrophysics Data System (ADS)

Lu, J.

2016-12-01

Understanding the transport of branched glycerol dialkyl glycerol tetraethers (brGDGTs) along the soil-river-lake transect is of vital importance, which helps discriminate the autochthonous from allochthonous contribution of brGDGTs in lake and river environment and favors the application of brGDGT-based proxies in paleo-reconstruction. We collected the sediment samples from the Qinghai Lake, the largest saline lake in China, as well as the river sediments and catchment soils, to examine the difference in the distribution of 5- vs. 6-methyl brGDGTs along the soil-river-lake transect. The brGDGT distributions were found to show a large variation along the transect, which can be reflected by the MBT'-derived indices and IR (isomer ratio) indices. There is a considerable difference in brGDGT distributions between soil and the river sediment. The inflowing rivers likely receive terrestrial brGDGT input to a variable degree. BrGDGTs in the Buha river are primarily of autochthonous origin whereas other ephemeral streams, like the Heima river, exhibit a similar brGDGT distribution to the surrounding soils, reflecting that these compounds are likely derived from soils. A higher quantity of 6-methyl brGDGTs and brGDGT-Ia was observed in the lake than in the river sediments, pointing to a preferential degradation of 5-methyl brGDGTs and/or an increase of in situ production of 6-methyl brGDGTs in the lake. Besides the difference in brGDGT distributions caused by the transportation and in situ production along the transect, we also identified the difference caused by several driving factors in different environments. In arid and alkaline soils, both CBT' and IR indices have strong correlations with soil pH even within the narrow pH range. However, we find a clear relationship of CBT with water salinity in Buha river. The difference in soil and river leads to a complicated interpretation for the CBT (CBT') index. In the lake, the MBT' (specially represented by MBT'5ME and MBT'6

Changes in river water temperature between 1980 and 2012 in Yongan watershed, eastern China: Magnitude, drivers and models

NASA Astrophysics Data System (ADS)

Chen, Dingjiang; Hu, Minpeng; Guo, Yi; Dahlgren, Randy A.

2016-02-01

Climate warming is expected to have major impacts on river water quality, water column/hyporheic zone biogeochemistry and aquatic ecosystems. A quantitative understanding of spatio-temporal air (Ta) and water (Tw) temperature dynamics is required to guide river management and to facilitate adaptations to climate change. This study determined the magnitude, drivers and models for increasing Tw in three river segments of the Yongan watershed in eastern China. Over the 1980-2012 period, Tw in the watershed increased by 0.029-0.046 °C yr-1 due to a ∼0.050 °C yr-1 increase of Ta and changes in local human activities (e.g., increasing developed land and population density and decreasing forest area). A standardized multiple regression model was developed for predicting annual Tw (R2 = 0.88-0.91) and identifying/partitioning the impact of the principal drivers on increasing Tw:Ta (76 ± 1%), local human activities (14 ± 2%), and water discharge (10 ± 1%). After normalizing water discharge, climate warming and local human activities were estimated to contribute 81-95% and 5-19% of the observed rising Tw, respectively. Models forecast a 0.32-1.76 °C increase in Tw by 2050 compared with the 2000-2012 baseline condition based on four future scenarios. Heterogeneity of warming rates existed across seasons and river segments, with the lower flow river and dry season demonstrating a more pronounced response to climate warming and human activities. Rising Tw due to changes in climate, local human activities and hydrology has a considerable potential to aggravate river water quality degradation and coastal water eutrophication in summer. Thus it should be carefully considered in developing watershed management strategies in response to climate change.

Hydrochemical and isotopic characteristics of estuarial seawater and river water of Bailanghe in Laizhou Bay, China

NASA Astrophysics Data System (ADS)

Yang, Qiaofeng; Xu, Suning; Wang, Ruijiu; Li, Wenpeng; Wang, Zhiyi; Mei, Junjun; Ding, Zhilei; Yang, Peijie; Yu, Liangju; Lv, Tieying; Bai, Gang; Kang, Wei

2016-04-01

In the study of seawater intrusion, seawater is usually taken as an end-member that mixes with other source(s). However, compared to standard seawater, the coastal seawater particularly that near the estuary, can be strongly influenced by the rivers into the sea and by coastal human activities. Their composition can be thus continuously changed and redistributed with space and time. Therefore, before investigating seawater intrusion in a certain area, it is essentially important to determine the features of the estuarine seawater (e.g. the mixture percentage between standard seawater and river water). In this study, we aimed to gain a clear situation of the seawater intrusion in Laizhou Bay, Southern Bohai, China. The issue aforementioned was investigated by comparing the stable isotopic and hydrochemical composition of the marine and river water collected in this area. Samples investigated include 5 surface water samples collected at the downstream of the Bailanghe and 7 seawater samples near the estuary of Laizhou Bay. Inert tracers (δD, δ18O, Cl, Br) and reaction tracers (Na, Mg, SO4, HCO3, Ca, NO3) are particularly analyzed. The major results are as follows: 1) All the river water samples fall below the Global Meteoric Water Line in the δD - δ18O diagram, reflecting evaporation of the upstream reservoir water. The seawater samples fall on the mixing line of standard seawater and the river water in the stable isotopic diagram. 2) The Cl-δ18O diagram indicates widespread dissolution of evaporate into the river, while high concentration of Ca and HCO3-, as well as the SO42- - Cl relation of the river water samples reflect the dissolution of CO2 , carbonate and sulfate in the atmosphere and on the ground. 3) The Br/Cl ratios of seawater samples are closed to the marine ratios. This together with the plots of major ions vs. Cl suggest that the seawater samples are originated from the mixture of standard seawater and river water. Therefore, when referring to the

Distribution and Source of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Dissolved Phase, Suspended Particulate Matter and Sediment from Weihe River in Northwest China

PubMed Central

Chen, Yuyun; Jia, Rui; Yang, Shengke

2015-01-01

Weihe River is a typical river located in the arid and semi-arid regions of Northwest China. In this study, the distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in Weihe River were investigated. The concentrations of ∑PAHs ranged from 351 to 4427 ng/L with a mean value of 835.4 ng/L in water dissolved phase (WDP), from 3557 ng/L to 147,907 ng/L with a mean value of 20,780 ng /L in suspended particulate matter (SPM), and from 362 to 15,667 ng/g dry weight (dw) with a mean value of 2000 ng/g dw in sediment, respectively. The concentrations of PAHs in Weihe River were higher compared with other rivers in the world. In both WDP and sediment, the highest concentrations of ∑PAHs were observed in the middle reach, while the lowest concentrations of ∑PAHs were found in the lower reach. For SPM, however, the PAHs concentrations in the lower reach were highest and the PAHs concentrations in the upper reach were lowest. The ratios of anthracene/(anthracene + phenanthrene) and fluoranthene/(fluoranthene + pyrene) reflected a pattern of both pyrolytic and petrogenic input of PAHs in Weihe River. The potential ecosystem risk assessment indicated that harmful biological impairments occur frequently in Weihe River. PMID:26561824

Comparison of hyporheic flow and water quality in open and tree-covered banks downstream of Xin'an River dam, China

NASA Astrophysics Data System (ADS)

Liu, D.

2017-12-01

Plants, especially trees, in the riparian zone may have a significant impact on the flow rate, temperature and chemical properties of groundwater. A field study was conducted in the downstream bank of the Xin'an River dam, Zhejiang, China. In the field, two areas of about 20 meters apart were chosen, of which one was a open place and the other was covered with many orange trees. Comparison of hyporheic flow and water quality in the open and tree-covered banks were made by monitoring the water level, water temperature, water chemistry (March, 2015) along the cross sections perpendicular to the river. The analyses indicated that water level around the trees was relatively low in the day and high in the evening, thus changed the direction and magnitude of the natural groundwater flow velocity, totally strengthened the hyporheic exchange between the groundwater and river. The trees also changed the temperature distribution of the natural river bank, and induced the wider infiltration range of the low-temperature water. The temperature around the trees was relatively low in the day, yet it was high in the evening. Dissolved oxygen (DO) and electricity conductivity (EC) around the trees were significantly increased, yet the pH was almost unaffected.

The '333' integrated strategy for effective pollution control and its application to the heavily polluted Jialu River in north China.

PubMed

Huang, Yu; Sun, Jie; Li, Aimin; Xie, Xianchuan

2018-05-01

In this study, an integrated approach named the '333' strategy was applied to pollution control in the Jialu River, in northern China, which is heavily burdened with anthropogenic pollution. Due to a deficiency of the natural ecological inflow, the Jialu River receives predominantly industrial and municipal effluent. The '333' strategy is composed of three steps of pollution control including industrial point-source pollution control, advanced treatment of municipal wastewater, and ecological restoration; three increased stringency emission standards; and three stages of reclamation. Phase 1 of the '333' strategy focuses on industrial point-source pollution control; phase 2 aims to harness municipal wastewater and minimize sewage effluents using novel techniques for advanced water purification; phase 3 of the '333' strategy focuses on the further purification of effluents flowing into Jialu River with the employment of an engineering-based ecological restoration project. The application of the '333' strategy resulted in the development of novel techniques for water purification including modified magnetic resins (NDMP resin), a two-stage internal circulation anaerobic reactor (IC reactor) and an ecological restoration system. The results indicate that water quality in the river was significantly improved, with increased concentrations of dissolved oxygen (DO), as well as reduction of COD by 42.8% and NH 3 -N by 61.4%. In addition, it was observed that the total population of phytoplankton in treated river water notably increased from only one prior to restoration to 8 following restoration. This system also provides a tool for pollution control of other similar industrial and anthropogenic source polluted rivers.

[Phytoplankton's community structure and its relationships with environmental factors in the rivers of Tongling City, Anhui Province of East China in winter].

PubMed

Wang, Li; Wei, Wei; Zhou, Ping; Li, Yang; Sun, Qing-Ye

2013-01-01

Tongling is one of the main non-ferrous metal mining areas in China, and the biodiversity in the river ecosystem of this area is seriously affected by heavy metals as a result of mining activities. In the winter in 2010, an investigation was conducted on the community structure of phytoplankton and its relationships with environmental factors in the main sections of the rivers in Tongling. A total of 203 phytoplankton species were identified, belonging to 96 genera and 8 phyla. The community structure of the phytoplankton differed obviously in different river sections, but the communities were all dominated by Bacillariophyta, Chlorophyta and Cyanophyta. The phytoplankton abundance ranged from 9.1 x 10(3) to 6.5 x 10(7) cells x L(-1), and the quantity of the phytoplankton in the river sections directly carried with mining waste water was significantly low. The Shannon index of the phytoplankton community at different sampling sites ranged from 0 to 3.45, with a significant discrepancy in different river sections. There existed significant correlations between the density and group number of phytoplankton and the COD(Cr) and cadmium, copper and zinc concentrations in the rivers, and the concentrations of river total nitrogen, NH4(+)-N, NO3(-)-N, and copper, COD(Cr) and pH were the main environmental variables affecting the phytoplankton' s community structure and its spatial distribution. Although the nutritional status of the river waters had greater effects on the community structure of phytoplankton, the effects of the heavy metals there from mining enterprises could not be neglected.

Simulating and predicting snow and glacier meltwater to the runoff of the Upper Mekong River basin in Southwest China

NASA Astrophysics Data System (ADS)

Han, Z.; Long, D.; Hong, Y.

2017-12-01

Snow and glacier meltwater in cryospheric regions replenishes groundwater and reservoir storage and is critical to water supply, hydropower development, agricultural irrigation, and ecological integrity. Accurate simulating and predicting snow and glacier meltwater is therefore fundamental to develop a better understanding of hydrological processes and water resource management for alpine basins and its lower reaches. The Upper Mekong River (or the Lancang River in China) as one of the most important transboundary rivers originating from the Tibetan Plateau (TP), features active dam construction and complicated water resources allocation of the stakeholders. Confronted by both climate change and significant human activities, it is imperative to examine contributions of snow and glacier meltwater to the total runoff and how it will change in the near future. This will greatly benefit hydropower development in the upper reach of the Mekong and better water resources allocation and management across the relevant countries. This study aims to improve snowfall and snow water equivalent (SWE) simulation using improved methods, and combines both modeling skill and remote sensing (i.e., passive microwave-based SWE, and satellite gravimetry-based total water storage) to quantify the contributions of snow and glacier meltwater there. In addition, the runoff of the Lancang River under a range of climate change scenarios is simulated using the improved modeling scheme to evaluate how climate change will impact hydropower development in the upper reaches.

Simulation and evaluation of pollution load reduction scenarios for water environmental management: a case study of inflow river of Taihu Lake, China.

PubMed

Zhang, Ruibin; Qian, Xin; Zhu, Wenting; Gao, Hailong; Hu, Wei; Wang, Jinhua

2014-09-09

In the beginning of the 21st century, the deterioration of water quality in Taihu Lake, China, has caused widespread concern. The primary source of pollution in Taihu Lake is river inflows. Effective pollution load reduction scenarios need to be implemented in these rivers in order to improve the water quality of Taihu Lake. It is important to select appropriate pollution load reduction scenarios for achieving particular goals. The aim of this study was to facilitate the selection of appropriate scenarios. The QUAL2K model for river water quality was used to simulate the effects of a range of pollution load reduction scenarios in the Wujin River, which is one of the major inflow rivers of Taihu Lake. The model was calibrated for the year 2010 and validated for the year 2011. Various pollution load reduction scenarios were assessed using an analytic hierarchy process, and increasing rates of evaluation indicators were predicted using the Delphi method. The results showed that control of pollution from the source is the optimal method for pollution prevention and control, and the method of "Treatment after Pollution" has bad environmental, social and ecological effects. The method applied in this study can assist for environmental managers to select suitable pollution load reduction scenarios for achieving various objectives.

Simulation and Evaluation of Pollution Load Reduction Scenarios for Water Environmental Management: A Case Study of Inflow River of Taihu Lake, China

PubMed Central

Zhang, Ruibin; Qian, Xin; Zhu, Wenting; Gao, Hailong; Hu, Wei; Wang, Jinhua

2014-01-01

In the beginning of the 21st century, the deterioration of water quality in Taihu Lake, China, has caused widespread concern. The primary source of pollution in Taihu Lake is river inflows. Effective pollution load reduction scenarios need to be implemented in these rivers in order to improve the water quality of Taihu Lake. It is important to select appropriate pollution load reduction scenarios for achieving particular goals. The aim of this study was to facilitate the selection of appropriate scenarios. The QUAL2K model for river water quality was used to simulate the effects of a range of pollution load reduction scenarios in the Wujin River, which is one of the major inflow rivers of Taihu Lake. The model was calibrated for the year 2010 and validated for the year 2011. Various pollution load reduction scenarios were assessed using an analytic hierarchy process, and increasing rates of evaluation indicators were predicted using the Delphi method. The results showed that control of pollution from the source is the optimal method for pollution prevention and control, and the method of “Treatment after Pollution” has bad environmental, social and ecological effects. The method applied in this study can assist for environmental managers to select suitable pollution load reduction scenarios for achieving various objectives. PMID:25207492

Influence of the characteristics of atmospheric boundary layer on the vertical distribution of air pollutant in China's Yangtze River Delta

NASA Astrophysics Data System (ADS)

Wang, Chenggang; Cao, Le

2016-04-01

Air pollution occurring in the atmospheric boundary layer is a kind of weather phenomenon which decreases the visibility of the atmosphere and results in poor air quality. Recently, the occurrence of the heavy air pollution events has become more frequent all over Asia, especially in Mid-Eastern China. In December 2015, the most severe air pollution in recorded history of China occurred in the regions of Yangtze River Delta and Beijing-Tianjin-Hebei. More than 10 days of severe air pollution (Air Quality Index, AQI>200) appeared in many large cities of China such as Beijing, Tianjin, Shijiazhuang and Baoding. Thus, the research and the management of the air pollution has attracted most attentions in China. In order to investigate the formation, development and dissipation of the air pollutions in China, a field campaign has been conducted between January 1, 2015 and January 28, 2015 in Yangtze River Delta of China, aiming at a intensive observation of the vertical structure of the air pollutants in the atmospheric boundary layer during the time period with heavy pollution. In this study, the observation data obtained in the field campaign mentioned above is analyzed. The characteristics of the atmospheric boundary layer and the vertical distribution of air pollutants in the city Dongshan located in the center of Lake Taihu are shown and discussed in great detail. It is indicated that the stability of the boundary layer is the strongest during the nighttime and the early morning of Dongshan. Meanwhile, the major air pollutants, PM2.5 and PM10 in the boundary layer, reach their maximum values, 177.1μg m-3 and 285μg m-3 respectively. The convective boundary layer height in the observations ranges from approximately 700m to 1100m. It is found that the major air pollutants tend to be confined in a relatively shallow boundary layer, which represents that the boundary layer height is the dominant factor for controlling the vertical distribution of the air pollutants. In

Petrography, fluid inclusion and isotope studies in Ordovician carbonate reservoirs in the Shunnan area, Tarim basin, NW China: Implications for the nature and timing of silicification

NASA Astrophysics Data System (ADS)

Lu, Ziye; Chen, Honghan; Qing, Hairuo; Chi, Guoxiang; Chen, Qianglu; You, Donghua; Yin, Hang; Zhang, Siyang

2017-08-01

The Shunnan (SN) area, located in the center of the Tarim basin, NW China, is a gas field discovered in 2013, where the gas is hosted from deeply buried Ordovician carbonate reservoirs with burial depth > 6000 m and temperature > 190 °C. The most important reservoir rocks in the SN area are silicified limestones, which are characterized by multiple generations/types of authigenic quartz (Qz1-Qz2) and coarse calcite cement (CC1-CC3), in addition to other diagenetic phases. Qz1 is a replacement quartz postdating burial stylolites in both limestone and strongly silicified limestone, and Qz2 are equant and bladed quartz cements developed in fractures or vugs in strongly silicified limestone, also postdating burial stylolite. CC1 is a coarse calcite cement found in the vugs, which postdates medium crystalline dolomite and predates saddle dolomite. CC2 (including CC2a, CC2b and CC2c) is the calcite postdating Qz1 and burial stylolites. CC2a is found in fractures in limestone or slightly silicified limestone. CC2b, CC2c and CC3 are only identified in strongly silicified limestone. CC2b fills intercrystalline pores of Qz1, and CC2c fills fractures, predating Qz2. CC3 is precipitated in remaining space left by Qz2c in fractures or vugs. Sr isotopes were analyzed in CC2a and CC2c. CC2a has 87Sr/86Sr ratios of 0.70890-0.70917. CC2c is characterized with 87Sr/86Sr ratios of 0.70949-0.70972. Fluid inclusions were studied in all the quartz and coarse calcite cements. Fluid inclusions in CC2a are characterized by Th values of 118-131 °C and salinities of 22.9-25.2 wt% NaCl + CaCl2. Fluid inclusions from Qz2a, Qz2b, CC2b and CC2c have Th values of 143-166 °C and salinities of 14.7-23.7 wt% NaCl + CaCl2. Fluid inclusions in Qz2c are characterized by Th values of 125-132 °C and salinities of 24.8-26.8 wt% NaCl + CaCl2, and those in CC3 by Th values of 86-101 °C and salinities of 22.9-25.2 wt% NaCl + CaCl2. The Th drop, from Qz2a, Qz2b and CC2c to Qz2c and CC3, cannot be

Mesoscale Dynamics, Lateral and Vertical Mixing in China Seas and Western Pacific

DTIC Science & Technology

2010-09-30

CDW) of Yangtze River of the East China Sea. APPROACH Analysis of field data collected in previous years in ECS and SCS and obtaining of new data in...in the Changjiang ( Yangtze River) Diluted Water of the East China Sea (CDW region: λ = 30°49’N, ϕ = 122°56’E; the mean depth HB = 38 m). a) b

Seasonal variation and partitioning of endocrine disrupting chemicals in waters and sediments of the Pearl River system, South China.

PubMed

Gong, Jian; Duan, Dandan; Yang, Yu; Ran, Yong; Chen, Diyun

2016-12-01

Endocrine disrupting chemicals (EDCs) were seasonally investigated in surface water, suspended particulate matter, and sediments of the Pearl River Delta (PRD), South China. EDC concentrations in the surface water were generally higher in the summer than in winter. The surface water in the investigated rivers was heavily contaminated by the phenolic xenoestrogens. Moreover, the in-situ log K soc and log K poc values and their regression with log K ow in the field experiments suggest that binding mechanisms other than hydrophobic interaction are present for the sedimentary organic carbon and particulate organic carbon (SOC/POC). The logK soc -logK ow and logK poc -logK ow regression analyses imply that higher complexity of nonhydrophobic interactions with EDCs is present on the SOC samples comparing with the POC samples, which is related to their different sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Risk and toxicity assessments of heavy metals in sediments and fishes from the Yangtze River and Taihu Lake, China.

PubMed

Fu, Jie; Hu, Xin; Tao, Xiancong; Yu, Hongxia; Zhang, Xiaowei

2013-11-01

Heavy metal pollution is one of the most serous environmental issues globally. To evaluate the metal pollution in Jiangsu Province of China, the total concentrations of heavy metals in sediments and fishes from the Yangtze River and Taihu Lake were analyzed. Ecological risk of sediments and human health risk of fish consumption were assessed respectively. Furthermore, toxicity of samples on expression of the stress responsive genes was evaluated using microbial live cell-array method. The results showed that the heavy metals concentrations in sediments from the Yangtze River were much higher than those in sediments from the Taihu Lake. However, the fishes from the Taihu Lake had higher concentrations of heavy metals than fishes from the Yangtze River. Ecological risk evaluation showed that the heavy metal contaminants in sediments from the Yangtze River posed higher risk of adverse ecological effects, while sediments from the study areas of Taihu Lake were relatively safe. Health risk assessment suggested that the heavy metals in fishes of both Yangtze River and Taihu Lake might have risk of adverse health effects to human. The toxicity assessment indicated that the heavy metals in these sediments and fishes showed transcriptional effects on the selected 21 stress responsive genes, which were involved in the pathways of DNA damage response, chemical stress, and perturbations of electron transport. Together, this field investigation combined with chemical analysis, risk assessment and toxicity bioassay would provide useful information on the heavy metal pollution in Jiangsu Province. Copyright © 2013 Elsevier Ltd. All rights reserved.

Spatial and temporal variations in prehistoric human settlement and their influencing factors on the south bank of the Xar Moron River, Northeastern China

NASA Astrophysics Data System (ADS)

Jia, Xin; Yi, Shuangwen; Sun, Yonggang; Wu, Shuangye; Lee, Harry F.; Wang, Lin; Lu, Huayu

2017-03-01

The West Liao River Basin is the hub of ancient civilizations as well as the birthplace of rain-fed agriculture in Northern China. In the present study, based on 276 archaeological sites on the south bank of the Xar Moron River, Northeastern China, we trace the changes in prehistoric cultures as well as the shifts in the spatial and temporal patterns of human settlement in the West Liao River Basin. Location information for those sites was obtained from fieldwork. Factors such as climate change, landform evolution of the Horqin Dunefield, and subsistence strategies practiced at the sites were extracted via the meta-analysis of published literature. Our results show that the Holocene Optimum promoted the emergence of Neolithic Culture on the south bank of the Xar Moron River. Monsoon failure might have caused the periodic collapse or transformation of prehistoric cultures at (6.5, 4.7, 3.9, and 3.0) kyr B.P., leaving spaces for new cultural types to develop after these gaps. The rise and fall of different cultures was also determined by subsistence strategies. The Xiaoheyan Culture, with mixed modes of subsistence, weakened after 4.7 kyr B.P., whereas the Upper Xiajiadian Culture, supported by sheep breeding, expanded after 3.0 kyr B.P. Global positioning system data obtained from the archaeological sites reveal that cultures with different subsistence strategies occupied distinct geographic regions. Humans who subsisted on hunting and gathering resided at higher altitudes during the Paleolithic Age (1074 m a.s.l.). Mixed subsistence strategies led humans to settle down at 600-1000 m a.s.l. in the Neolithic Age. Agricultural activities caused humans to migrate to 400-800 m a.s.l. in the early Bronze Age, whereas livestock production shifted human activities to 800-1200 m a.s.l. in the late Bronze Age.

Morphology and mechanism of the very large dunes in the tidal reach of the Yangtze River, China

NASA Astrophysics Data System (ADS)

Shuwei, Zheng; Heqin, Cheng; Shuaihu, Wu; Shengyu, Shi; Wei, Xu; Quanping, Zhou; Yuehua, Jiang

2017-05-01

High-resolution multibeam data was used to interpret the surface morphology of very large dunes (VLDs) in the tidal reach of the Yangtze River, China. These VLDs can be divided into three categories according to their surface morphological characteristics. (1) VLDs-I: those with a smooth surface and cross-section; (2) VLDs-II: those accompanied by secondary dunes; (3) VLDs-III: those accompanied by secondary dunes and numerous elliptical pits. Parameters and spatial distribution of VLDs, and bed surface sediment were analyzed in the laboratory. Overall, channel morphology is an important factor affecting the development of VLDs, and channels with narrow and straight and certain water surface slope are facilitating the development of VLDs by constraining stream power. Meanwhile, distribution density of VLDs depicts a decreasing trend from Chizhou towards the estuary, are probably influenced by channel morphology and width. Associated pits in VLDs-III change the 3D dune morphology by distributing in secondary dunes as beads. The Three Gorges Dam project (TGP) leads to the bed surface sediment activity frequently and leads to the riverbed surface sediment coarsens, which promotes the further development of dunes. Moreover, other human activities, such as river regulation project, sand mining and Deep Water Channel Regulation Project have changed the regional river boundary conditions and hydrodynamic conditions are influential on the development of VLDs.

Temporal trend and source apportionment of water pollution in different functional zones of Qiantang River, China.

PubMed

Su, Shiliang; Li, Dan; Zhang, Qi; Xiao, Rui; Huang, Fang; Wu, Jiaping

2011-02-01

The increasingly serious river water pollution in developing countries poses great threat to environmental health and human welfare. The assignment of river function to specific uses, known as zoning, is a useful tool to reveal variations of water environmental adaptability to human impact. Therefore, characterizing the temporal trend and identifying responsible pollution sources in different functional zones could greatly improve our knowledge about human impacts on the river water environment. The aim of this study is to obtain a deeper understanding of temporal trends and sources of water pollution in different functional zones with a case study of the Qiantang River, China. Measurement data were obtained and pretreated for 13 variables from 41 monitoring sites in four categories of functional zones during the period 1996-2004. An exploratory approach, which combines smoothing and non-parametric statistical tests, was applied to characterize trends of four significant parameters (permanganate index, ammonia nitrogen, total cadmium and fluoride) accounting for differences among different functional zones identified by discriminant analysis. Aided by GIS, yearly pollution index (PI) for each monitoring site was further mapped to compare the within-group variations in temporal dynamics for different functional zones. Rotated principal component analysis and receptor model (absolute principle component score-multiple linear regression, APCS-MLR) revealed that potential pollution sources and their corresponding contributions varied among the four functional zones. Variations of APCS values for each site of one functional zone as well as their annual average values highlighted the uncertainties associated with cross space-time effects in source apportionment. All these results reinforce the notion that the concept of zoning should be taken seriously in water pollution control. Being applicable to other rivers, the framework of management-oriented source apportionment

Artificial neural network modeling of dissolved oxygen in the Heihe River, Northwestern China.

PubMed

Wen, Xiaohu; Fang, Jing; Diao, Meina; Zhang, Chuanqi

2013-05-01

Identification and quantification of dissolved oxygen (DO) profiles of river is one of the primary concerns for water resources managers. In this research, an artificial neural network (ANN) was developed to simulate the DO concentrations in the Heihe River, Northwestern China. A three-layer back-propagation ANN was used with the Bayesian regularization training algorithm. The input variables of the neural network were pH, electrical conductivity, chloride (Cl(-)), calcium (Ca(2+)), total alkalinity, total hardness, nitrate nitrogen (NO3-N), and ammonical nitrogen (NH4-N). The ANN structure with 14 hidden neurons obtained the best selection. By making comparison between the results of the ANN model and the measured data on the basis of correlation coefficient (r) and root mean square error (RMSE), a good model-fitting DO values indicated the effectiveness of neural network model. It is found that the coefficient of correlation (r) values for the training, validation, and test sets were 0.9654, 0.9841, and 0.9680, respectively, and the respective values of RMSE for the training, validation, and test sets were 0.4272, 0.3667, and 0.4570, respectively. Sensitivity analysis was used to determine the influence of input variables on the dependent variable. The most effective inputs were determined as pH, NO3-N, NH4-N, and Ca(2+). Cl(-) was found to be least effective variables on the proposed model. The identified ANN model can be used to simulate the water quality parameters.

Spatial assessment of water quality using chemometrics in the Pearl River Estuary, China

NASA Astrophysics Data System (ADS)

Wu, Meilin; Wang, Youshao; Dong, Junde; Sun, Fulin; Wang, Yutu; Hong, Yiguo

2017-03-01

A cruise was commissioned in the summer of 2009 to evaluate water quality in the Pearl River Estuary (PRE). Chemometrics such as Principal Component Analysis (PCA), Cluster analysis (CA) and Self-Organizing Map (SOM) were employed to identify anthropogenic and natural influences on estuary water quality. The scores of stations in the surface layer in the first principal component (PC1) were related to NH4-N, PO4-P, NO2-N, NO3-N, TP, and Chlorophyll a while salinity, turbidity, and SiO3-Si in the second principal component (PC2). Similarly, the scores of stations in the bottom layers in PC1 were related to PO4-P, NO2-N, NO3-N, and TP, while salinity, Chlorophyll a, NH4-N, and SiO3-Si in PC2. Results of the PCA identified the spatial distribution of the surface and bottom water quality, namely the Guangzhou urban reach, Middle reach, and Lower reach of the estuary. Both cluster analysis and PCA produced the similar results. Self-organizing map delineated the Guangzhou urban reach of the Pearl River that was mainly influenced by human activities. The middle and lower reaches of the PRE were mainly influenced by the waters in the South China Sea. The information extracted by PCA, CA, and SOM would be very useful to regional agencies in developing a strategy to carry out scientific plans for resource use based on marine system functions.

U-Pb ages of detrital zircon from Cenozoic sediments in the southwestern Tarim Basin, NW China: Implications for Eocene-Pliocene source-to-sink relations and new insights into Cretaceous-Paleogene magmatic sources

NASA Astrophysics Data System (ADS)

Yang, Wei; Fu, Ling; Wu, Chaodong; Song, Yan; Jiang, Zhenxue; Luo, Qun; Zhang, Ziya; Zhang, Chen; Zhu, Bei

2018-05-01

A detailed investigation of potential provenance is still lacking in the southwestern Tarim Basin, which restricts our complete understanding of Cenozoic source-to-sink relations between the basin interior and the Pamir salient - western Kunlun Mountain Range. Debate also exists concerning the potential sources of the Paleogene and Cretaceous igneous detritus present in the Cenozoic sedimentary sequences. Here, we present U-Pb (LA-ICP-MS) ages of detrital zircons from the continuous Eocene-Pliocene sediment series in the well-exposed Aertashi section to investigate changes in sediment provenance through time. The U-Pb detrital zircon ages range widely from 45 to 3204 Ma and can be divided into seven main groups: 45-65 Ma (sub-peak at 49 Ma), 67-103 Ma (sub-peak at 95 Ma), 196-251 Ma (sub-peak at 208 Ma), 252-416 Ma (sub-peak at 296 Ma), 417-540 Ma (sub-peak at 446 Ma), 550-1429 Ma (sub-peaks at 614 Ma, 828 Ma and 942 Ma) and 1345-3204 Ma (sub-peaks at 1773 Ma and 2480 Ma). These zircons were mainly derived from the western Kunlun Mountain Range and northern Pamir salient to the west and south. The evolution of the provenance and source-to-sink relationship patterns in the southwestern Tarim Basin can be divided into three stages: (1) The Middle Eocene to Lower Oligocene sediments display a wide variety of detrital zircon ages, suggesting that the source area was extensive. (2) A major change in provenance occurred during the Late Oligocene to Early Miocene and was characterized by an abrupt increase in the proportion of Triassic and Lower Paleozoic igneous components, implying a significant adjustment in topography induced by the initial uplift and exhumation of the western Kunlun Mountain Range and northern Pamir salient. (3) In the Late Miocene, the source-to-sink system transformed again, and contributions of Triassic to Lower Paleozoic material weakened substantially due to the sufficient indentation of the Pamir salient. Our integrated analyses of zircon

Blood lead level is associated with non-alcoholic fatty liver disease in the Yangtze River Delta region of China in the context of rapid urbanization.

PubMed

Zhai, Hualing; Chen, Chi; Wang, Ningjian; Chen, Yi; Nie, Xiaomin; Han, Bing; Li, Qin; Xia, Fangzhen; Lu, Yingli

2017-08-31

China has undergone rapid urbanization in the past three decades. We aimed to report blood lead level (B-Pb) in the most rapidly urbanized Yangtze River Delta Region of China, and explore the association B-Pb and non-alcoholic fatty liver disease (NAFLD). Our data source was the SPECT-China study. We enrolled 2011 subjects from 6 villages in the Yangtze River Delta Region. Lead was measured by atomic absorption spectrometry. According to abdominal ultrasound, residents were divided into normal and NAFLD groups. In total, 824 (41.0%) were diagnosed with NAFLD. Medians (interquartile range) of B-Pb were 5.29 μg/dL (3.60-7.28) [0.25 μmol/L (0.17-0.35)] for men and 4.49 μg/dL (2.97-6.59) [0.22 μmol/L (0.14-0.32)] for women. In both genders, the NAFLD group had significantly greater B-Pb than normal group (both P < 0.001). The prevalence of NAFLD significantly increased with increasing B-Pb quartiles in men (P for trend = 0.032) and women (P for trend = 0.001). Residents in Shanghai had significantly greater B-Pb (P < 0.001) and a higher prevalence of NAFLD (P < 0.001). Compared with women in the lowest quartile of BLL, OR of NAFLD in women in the highest quartile was 1.613 (95%CI 1.082-2.405) (P for trend = 0.019) after multivariable adjustment. In men, this association showed marginal significance (OR 2.168, 95%CI 0.989-4.750, P for trend = 0.063). B-Pb in Chinese residents in the Yangtze River Delta Region were much higher than in developed countries. Elevated B-Pb was associated with an increased risk of NAFLD, especially in women.

Spatial and temporal distributions of polycyclic aromatic hydrocarbons in sediments from the Songhua River, China

NASA Astrophysics Data System (ADS)

Dong, D.; Guo, Z.; Liu, X.; Hua, X.; Liang, D.

2013-12-01

Polycyclic aromatic hydrocarbons (PAHs), a class of typical persistent organic pollutants, widely exist in the environment and are potentially harmful to human health. They can enter the waters through atmospheric deposition, soil leaching, shipping, sewage discharges and surface runoff. In recent years, many studies on the distributions of PAHs in major rivers, lakes and bays around the world have been carried out. In this study, 9 surface sediments (0-10cm) were sampled from the Songhua River in Jilin and Heilongjiang provinces. The contents of 16 PAHs in the US Environmental Protection Agency list of priority pollutants were determined and their spatial distributions were discussed. Sediment cores (50cm length) in three oxbow lakes in this area were also collected and cut into 2 cm thickness sub-samples. PAHs concentrations in these samples were determined and the cores were dated using a 210Pb geochronology technique. Finally, the sedimentary history of PAHs in the Songhua River since the 1920s was revealed. Results indicated that total concentration of the 16 PAHs analyzed in the surface sediments was 187-2079 ng/g (dry weight), and the mean was 1029 ng/g. Sediments collected from near urban areas (Jilin and Harbin City) contained higher PAHs content. Compared with the domestic and international rivers, the PAHs content in this river sediments is at a medium level. The PAHs profiles showed that 2-3 ring PAHs, especially naphthalene, were dominant in all of the samples. Sedimentary flux can reflect the accumulating history of pollutants better. The PAHs fluxes were low and varied little from the 1920s to 1970s, but higher PAH fluxes were found since the 1980s in each core (Fig. 1). The PAHs sedimentary flux near Harbin City (Shuangcheng) was found changed remarkably. We inferred that the PAHs might be influenced by hydrological conditions, population mobility and economic activity in this area. PAHs sedimentary record in the Songhua River revealed that the

The crustal structure from the Altai Mountains to the Altyn Tagh fault, northwest China

USGS Publications Warehouse

Wang, Y.; Mooney, W.D.; Yuan, X.; Coleman, R.G.

2003-01-01

We present a new crustal section across northwest China based on a seismic refraction profile and geologic mapping. The 1100-km-long section crosses the southern margin of the Chinese Altai Mountains, Junggar Accretional Belt and eastern Junggar basin, easternmost Tianshan Mountains, and easternmost Tarim basin. The crustal velocity structure and Poisson's ratio (??), which provide a constraint on crustal composition, were determined from P and S wave data. Despite the complex geology, the crustal thickness along the entire profile is nearly uniform at 50 km. The thickest crust (56 km) occurs at the northern end of the profile beneath the Altai Mountains and the thinnest (46 km) crust is beneath the Junggar basin. Beneath surficial sediments, the crust is found to have three layers with P wave velocities (Vp) of 6.0-6.3, 6.3-6.6, and 6.9-7.0 km/s, respectively. The southern half of the profile, including the eastern Tianshan Mountains and eastern margin of the Tarim basin, shows low P wave velocities and ?? = 0.25 to a depth of 30 km, which suggests a quartz-rich, granitic upper crustal composition. The northern half of the profile below the Altai Mountains and Junggar Accretional Belt has a higher Poisson's ratio of ?? = 0.26-0.27 to a depth of 30 km, indicative of an intermediate crustal composition. The entire 1100-km-long profile is underlain by a 15-30 km thick high velocity (6.9-7.0 km/s; ?? = 0.26-0.28) lower-crustal layer that we interpret to have a bulk composition of mafic granulite. At the southern end of the profile, a 5-km-thick midcrustal low-velocity layer (Vp = 5.9 km/s, ?? = 0.25) underlies the Tianshan and the region to the south, and may be indicative of a near-horizontal detachment interface. Pn velocities are ???7.7-7.8 km/s between the Tianshan and the Junggar basin, and ???7.9-8.0 km/s below the Altai Mountains and eastern margin of the Tarim basin. We interpret the consistent three-layer stratification of the crust to indicate that the crust

Assessment of the national schistosomiasis control program in a typical region along the Yangtze River, China.

PubMed

Hu, Yi; Li, Si; Xia, Congcong; Chen, Yue; Lynn, Henry; Zhang, Tiejun; Xiong, Chenglong; Chen, Gengxin; He, Zonggui; Zhang, Zhijie

2017-01-01

Schistosomiasis remains a major public health problem in eastern China, particularly along the Yangtze River Basin. The latest national schistosomiasis control program (NSCP) was implemented in 2005 with the main goal of reducing the rate of infection to less than 5% by 2008 and 1% by 2015. To assess the progress, we applied a Bayesian spatio-temporal model to describe dynamics of schistosomiasis in Guichi, Anhui Province, China, using annual parasitological and environmental data collected within 41 sample villages for the period 2005-2011. Predictive maps of schistosomiasis showed that the disease prevalence remains constant and low. Results of uncertainty analysis, in the form of probability contour maps (PCMs), indicated that the first goal of "infection rate less than 5% by 2008" was fully achieved in the study area. More longitudinal data for schistosomiasis are needed for the assessment of the second goal of "infection rate less than 1% by 2015". Compared with the traditional way of mapping uncertainty (e.g., variance or mean-square error), our PCMs provide more realistic information for schistosomiasis control. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

The Grain-size Patchiness of Braided Gravel-Bed Streams: Example of the Urumqi River (northeast Tian Shan, China)

NASA Astrophysics Data System (ADS)

Guerit, L.; Barrier, L.; Narteau, C.; Métivier, F.; Liu, Y.; Lajeunesse, E.; Gayer, E.; Malverti, L.; Meunier, P.; Ye, B.

2012-04-01

In gravel-beds rivers, sediments are sorted into patches of different grain-sizes. For single-thread streams, it has long been shown that this local granulometric sorting is closely linked to the channel morpho-sedimentary elements. For braided streams, this relation is still unclear. In such rivers, many observations of vertical sediment sorting has led to the definition of a surface and a subsurface layers. Because of this common stratification, methods for sampling gravel-bed rivers have been divided in two families. The surface layer is generally sampled by surface methods and the subsurface layer by volumetric methods. Yet, the equivalency between the two kind of techniques is still a key question. In this study, we characterized the grain-size distribution of the surface layer of the Urumqi River, a shallow braided gravel-bed river in China, by surface-count (Wolman grid-by-number) and volumetric (sieve-by-weight) sampling methods. An analysis of two large samples (212 grains and 3226 kg) show that these two methods are equivalent to characterize the river-bed surface layer. Then, we looked at the grain-size distributions of the river-bed morpho-sedimentary elements: (1) chutes at flow constrictions, which pass downstream to (2) anabranches and (3) bars at flow expansions. Using both sampling methods, we measured the diameter of more than 2300 grains and weight more than 6000 kg of grains larger than 4 mm. Our results show that the three morpho-sedimentary elements correspond only to two kinds of grain-size patches: (1) chutes composed of one coarse-grained top layer lying on finer deposits, and (2) anabranches and bars made up of finer-grained deposits more homogeneous in depth. On the basis of these quantitative observations, together with the concave or convex morphology of the different elements, we propose that chute patches form by erosion and transit with size-selective entrainment, whereas anabranch and bar patches rather develop and migrate by

Relationship between ancient bridges and population dynamics in the lower Yangtze River Basin, China.