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Sample records for huaihe river china

  1. Metal distribution and bioavailability in surface sediments from the Huaihe River, Anhui, China.

    PubMed

    Wang, Jie; Liu, Guijian; Lu, Lanlan; Liu, Houqi

    2016-01-01

    This study presents the total concentrations and chemical fractionations of metals (Cu, Pb, Zn, Ni, Fe, and Mn) in 54 surface sediment samples collected from the Huaihe River (Anhui Province) in eastern China. Compared with the average shale values, Zn and Pb exhibited the most substantial anthropogenic enrichment, especially in Fengtai and Huainan areas, the main industrial districts along the Huaihe River (Anhui Province). Low levels of Cu and Ni were observed in the sediments. Based on risk assessment code (RAC), the metals associated with weak acid soluble (F1) in the Huaihe River sediments followed the order: Mn > Zn > Cu > Pb > Ni > Fe. Manganese presented the most potential for releasing into the aqueous environment and can easily enter the food chain. Copper, zinc, nickel, and iron were found dominant in the residual fraction, implying that these four metals were strongly bound to the sediments. Lead showed a different partitioning pattern from that of other metals studied, with a large percentage in Fe-Mn oxide fraction, indicating that slight redox potential changes may make significant influence on the removability of Pb. Moreover, Cu in oxidizable (F3) and residual (F4) fractions presented high positive correlation with organic matter, which can explain the high percentage of Cu in these two fractions. PMID:26627208

  2. Residues of organochlorine pesticides (OCPs) in upper reach of the Huaihe River, East China.

    PubMed

    Feng, Jinglan; Zhai, Mengxiao; Liu, Qun; Sun, Jianhui; Guo, Jiajia

    2011-11-01

    Residues of HCHs and DDTs in surface water and suspended particulate matter (SPM) from upper reach of the Huaihe River, East China, were investigated. Levels of total HCHs (∑HCH) and total DDTs (∑DDT) in water detected by GC-ECD ranged from 0.85 to 12.77 ng L⁻¹ and from 3.54 to 33.59 ng L⁻¹, respectively. According to European and America water quality guidelines, HCHs were within safe levels while DDT would pose adverse biological effects. Distribution of OCPs in water indicated that input of tributaries was important factor for the Huaihe River. For OCPs in SPM, concentrations varied from 1.01 to 25.22 ng g⁻¹ for ∑HCH and not detected to 4.74 ng g⁻¹ for ∑DDT. Compared with sediment quality guidelines, HCHs and DDTs might have an ecological risk. The main reason for OCPs residues in the Huaihe River was usage of lindane and technical DDT. Furthermore, composition of DDTs reflected fresh inputs of dicofol mixture in some sites.

  3. Drought assessment using a multivariate drought index in the Huaihe River basin of Eastern China

    NASA Astrophysics Data System (ADS)

    Li, Q.; Zeng, M.; Wang, H.; Li, P.; Wang, K.; Yu, M.

    2015-06-01

    The Huaihe River Basin having China's highest population density (662 persons per km2) lies in a transition zone between the climates of North and South China, and is thus prone to drought. Therefore, the paper aims to develop an appropriate drought assessment approach for drought assessment in the Huaihe River basin, China. Based on the Principal Component Analysis of precipitation, evapotranspiration, soil moisture and runoff, the three latter variables of which were obtained by use of the Xin'anjiang model, a new multivariate drought index (MDI) was formulated, and its thresholds were determined by use of cumulative distribution function. The MDI, the Standardized Precipitation Index (SPI) and the self-calibrating Palmer Drought Severity Index (sc-PDSI) time series on a monthly scale were computed and compared during 1988, 1999/2000 and 2001 drought events. The results show that the MDI exhibited certain advantages over the sc-PDSI and the SPI in monitoring drought evolution. The MDI formulated by this paper could provide a scientific basis for drought mitigation and management, and references for drought assessment elsewhere in China.

  4. Trace organic pollutants in sediments from Huaihe River, China: Evaluation of sources and ecological risk

    NASA Astrophysics Data System (ADS)

    Wang, Ji-Zhong; Chen, Tian-Hu; Zhu, Cheng-Zhu; Peng, Shu-Chuan

    2014-05-01

    In the present study, a combination of multiple molecular markers was used to improve the identification of pollution sources in sediment samples collected from Huaihe River, China. No significant spatial variation of aliphatic hydrocarbons (normal alkanes, n-alkanes) was observed, whereas, relatively high concentrations of 28 polycyclic aromatic hydrocarbons (Σ28PAH) and 20 linear alkylbenzenes (Σ20LAB) in urban sediments and low concentrations of Σ28PAH and Σ20LAB in farm areas were determined. Overall, sediment samples collected from urban areas contained high concentration of Σ20LAB with low concentration of Σ28PAH which mostly originated from pyrolysis, while rural sediments had opposite trends, reflecting the significant input of domestic sewage in urban areas. Residual n-alkanes were mostly from natural sources with relatively low proportion of petrogenic input. For PAHs, the concentrations of diagentic perylene and pyrolytic PAHs from farm areas to urban areas tend to decrease and increase, respectively. Likely origins of pyrolytic PAHs were considered combustion of coal and petroleum related. In the village areas, pyrolytic PAHs were mostly contributed from coal and diesel combustion. Poor domestic wastewater treatment in rural areas caused low ratio of I/E. On the other hand, the results of total toxic benzo[a]pyrene (BaP) equivalent reveal the ecological risk by PAHs was negligible in Huaihe River.

  5. Drought monitoring based on TIGGE and distributed hydrological model in Huaihe River Basin, China.

    PubMed

    Zhao, Junfang; Xu, Jingwen; Xie, Xingmei; Lu, Houquan

    2016-05-15

    Drought assessment is important for developing measures to reduce agricultural vulnerability and thereby secure the livelihoods of those who depend on agriculture. This study uses four global ensemble weather prediction systems: the China Meteorological Administration (CMA), the European Centre for Medium-Range Weather Forecasts (ECMWF), the UK Met Office (UKMO), and the US National Centres for Environmental Prediction (NCEP) in the THORPEX (The Observing System Research and Predictability Experiment) Interactive Grand Global Ensemble (TIGGE) archive from 2006 to 2010. Based on results from the XXT (the first X denotes Xinanjiang, the second X denotes hybrid, and the T denotes TOPMODEL) distributed hydrological model, as well as soil moisture observations and digital elevation model (DEM) data, synthesized drought grades were established in the Huaihe River Basin of China. To filter out the impact of short-term fluctuations on observed soil moisture, a 30-day moving average was calculated. Use of the moving average significantly improves the correlation between observed soil moisture and simulated soil water deficit depth. Finally, a linear regression model describing the relationship between observed soil moisture and simulated soil water deficit depth was constructed. The deterministic regression coefficient was 0.5872, the correlation coefficient was 0.77, and the regression coefficient was -154.23. The trends in drought grades calculated using soil moisture and soil water deficit depth were found to be the same, and the grades agreed to within one level. Our findings highlight the importance of synthesizing drought grading when assessing drought using different soil moisture indicators in order to obtain a more comprehensive forecast of drought conditions.

  6. Drought monitoring based on TIGGE and distributed hydrological model in Huaihe River Basin, China.

    PubMed

    Zhao, Junfang; Xu, Jingwen; Xie, Xingmei; Lu, Houquan

    2016-05-15

    Drought assessment is important for developing measures to reduce agricultural vulnerability and thereby secure the livelihoods of those who depend on agriculture. This study uses four global ensemble weather prediction systems: the China Meteorological Administration (CMA), the European Centre for Medium-Range Weather Forecasts (ECMWF), the UK Met Office (UKMO), and the US National Centres for Environmental Prediction (NCEP) in the THORPEX (The Observing System Research and Predictability Experiment) Interactive Grand Global Ensemble (TIGGE) archive from 2006 to 2010. Based on results from the XXT (the first X denotes Xinanjiang, the second X denotes hybrid, and the T denotes TOPMODEL) distributed hydrological model, as well as soil moisture observations and digital elevation model (DEM) data, synthesized drought grades were established in the Huaihe River Basin of China. To filter out the impact of short-term fluctuations on observed soil moisture, a 30-day moving average was calculated. Use of the moving average significantly improves the correlation between observed soil moisture and simulated soil water deficit depth. Finally, a linear regression model describing the relationship between observed soil moisture and simulated soil water deficit depth was constructed. The deterministic regression coefficient was 0.5872, the correlation coefficient was 0.77, and the regression coefficient was -154.23. The trends in drought grades calculated using soil moisture and soil water deficit depth were found to be the same, and the grades agreed to within one level. Our findings highlight the importance of synthesizing drought grading when assessing drought using different soil moisture indicators in order to obtain a more comprehensive forecast of drought conditions. PMID:26930309

  7. [Net anthropogenic nitrogen input to Huaihe River Basin, China during 1990-2010].

    PubMed

    Zhang, Wang-shou; Su, Jing-jun; Du, Xin-zhong; Li, Xu-yong

    2015-06-01

    Social economy in Huaihe River Basin had undergone enormous changes during 1990-2010. The grain yield had increased by 58%, from 64.14 million tons to 101.21 million tons, and the urbanization rate had increased by 22%, from 13% to 35%. Assessing the negative impacts of these high intensive human activities caused by rapid social development on terrestrial ecosystem would serve as a scientific basis for quantitative management of regional ecology. This paper estimated the spatial and temporal distribution of net anthropogenic nitrogen input (NANI) in Huaihe River Basin during 1990-2010. The results showed that there was an increasing trend in NANI in the period of 1990-2001, and after that this trend was slower. The NANI increased from approximately 17232 kg N · km(-2) · a(-1) in 1990 to a peak of 28771 kg N · km(-2) · a(-1) in 2003, and then declined to 26415 kg N · km(-2) · a(-1) in 2010. Chemical fertilizer and atmospheric deposition were the largest two sources of NANI, followed by food & feed import and biological nitrogen. Contributions from both chemical fertilizer and atmospheric deposition had been increasing continuously, respectively from 64% and 16% in 1990 to 77% and 19%. Our findings implied that the shift from fertilizer-supported agriculture and fossil fuel-supported industry to sci-tech lead economic development is urgently needed. PMID:26572039

  8. [Coupling coordination measurement of urbanization and eco-environment system in Huaihe River Basin of China based on fuzzy matter element theory].

    PubMed

    Guo, Yue-Ting; Xu, Jian-Gang

    2013-05-01

    Based on the statistical data of urbanization and eco-environment of 35 cities in the Huaihe River Basin of China in 2010, an index system of urbanization-eco-environment system was established by using fuzzy matter element theory, and the weight of each indicator was calculated by entropy method. The improved function of the coupling coordination degree of urbanization and eco-environment was constructed to measure this coupling coordination degree in the Huaihe River Basin. In 2010, the development level of urbanization subsystem in the Basin was lower than that of the eco-environment subsystem, and the integrated coordination index of urbanization and eco-environment was 0.186, indicating that there was a gap between the two types of indicators. The average coupling degree of urbanization and eco-environment was 0.475, indicating that the urbanization-eco-environment system was at antagonistic stage. There was a greater difference in the development level of urbanization subsystem, but a smaller difference in the development level of eco-environment subsystem among the cities. The average value of the coordination degree of all the cities was 0.706, indicating that the Huaihe River Basin was at high coordination coupling stage, and the integrated coherence and synergistic effect of urbanization and eco-environment construction in the Huaihe River Basin was higher.

  9. Evaluation and analysis of RegCM3 simulated summer rainfall over the Huaihe River Basin of China

    NASA Astrophysics Data System (ADS)

    Zong, Peishu; Wang, Huijun

    2011-06-01

    This study evaluates the ability of the Abdus Salam International Center for Theoretical Physics (ICTP) version 3 Regional Climate Model (RegCM3) in simulating the summer rainfall amount and distribution and large-scale circulation over the Huaihe River basin of China. We conducted the simulation for the period of 1982-2001 and the wet year of 2003 to test the ensemble simulation capacity of RegCM3. First, by comparing the simulated rainfall amount and distribution against the observations, it is found that RegCM3 can reproduce the rainfall pattern and its annual variations. In addition, the simulated spatial patterns of 850-hPa wind and specific humidity fields are close to the observations, although the wind speed and humidity values are larger. Finally, the ensemble simulation of RegCM3 for summer 2003 failed to capture the spatial distribution and underestimated the magnitude of the precipitation anomalies, and the reasons are analyzed.

  10. Investigation into impacts of land-use changes on floods in the upper Huaihe River basin, China

    NASA Astrophysics Data System (ADS)

    Yu, M.; Li, Q.; Lu, G.; Wang, H.; Li, P.

    2015-06-01

    To investigate the agricultural land-use change on flood regime, the upper Huaihe River basin above the Dapoling station was selected as the case study site. Based on topography, land-use, hydrological and meteorological data in 1990s and 2010s, the improved distributed Xinanjiang model, with potential evapotranspiration being computed by coupling a dual-source evapotranspiration model with a simplified plant growth model, was adopted to simulate the daily and hourly rainfall-runoff processes over 1990s and 2010s, and then the effects of land-use change on flood volume, flood peak, occurring time of flood peak, the percentage of surface runoff component were investigated respectively. The results was interesting and indicated that impacts of land-use change on flood characteristics varied significantly with land-use types. The outputs could provide valuable references for flood risk management and water resources management in the Huaihe River basin.

  11. Temporal and spatial characteristics of the water pollutant concentration in Huaihe River Basin from 2003 to 2012, China.

    PubMed

    Dou, Ming; Zhang, Yan; Li, Guiqiu

    2016-09-01

    Based on the monitoring data of 78 monitoring stations from 2003 to 2012, five key water quality indexes (biochemical oxygen demand: BOD5, permanganate index: CODMn, dissolved oxygen: DO, ammonium nitrogen: NH3-N, and total phosphorus: TP) were selected to analyze their temporal and spatial characteristics in the highly disturbed Huaihe River Basin via Mann-Kendall trend analysis and boxplot analysis. The temporal and spatial variations of water pollutant concentrations in the Huaihe River Basin were investigated and analyzed to provide a scientific basis for water pollution control, water environment protection, and ecological restoration. The results indicated that the Yinghe River, Quanhe River, Honghe River, Guohe River, and Baohe River were the most seriously polluted rivers, followed by Hongze Lake, Luoma Lake, Yishuhe River, and Nansi Lake. BOD5, CODMn, and NH3-N were the major pollution indexes, for which the monitoring stations reported that more than 40 % of the water quality concentrations exceeded the class IV level. There were 21, 50, 36, and 21 monitoring stations that recorded significantly decreasing trends for BOD5, CODMn, NH3-N, and TP, respectively, and 39 monitoring stations showed a significantly increasing trend for DO. Moreover, the water quality concentrations had a certain concentricity and volatility according to boxplot analysis for the 20 monitoring stations. The majority of monitoring stations recorded a large fluctuation for the monitoring indexes in 2003 and 2004, which indicated that the water quality concentrations were unstable. According to the seasonal variations of the water quality concentrations in the mainstream of Huaihe River, the monthly variation trends of the BOD5, CODMn, DO, NH3-N, and TP concentrations were basically consistent among the seven monitoring stations. The BOD5, CODMn, NH3-N, and TP concentrations were affected by the change of the stream discharge; changes in DO and NH3-N concentrations were influenced by

  12. Development and application of a short- /long-term composited drought index in the upper Huaihe River basin, China

    NASA Astrophysics Data System (ADS)

    Yu, M.; Li, Q.; Lu, G.; Wang, H.; Li, P.

    2015-06-01

    Accurate and reliable drought monitoring is of primary importance for drought mitigation and reduction of social-ecological vulnerability. The aim of the paper was to propose a short-term/long-term composited drought index (CDI) which could be widely used for drought monitoring and early warning in China. In the study, the upper Huaihe River basin above the Xixian gauge station, which has been hit by severe droughts frequently in recent decades, was selected as the case study site. The short-term CDI was developed by the Principle Component Analysis of the self-calibrating Palmer Drought Severity Index (sc-PDSI), the 1- and 3-month Standardized Precipitation Evapotranspiration Index (SPEI), Z Index (ZIND), the Soil Moisture Index (SMI) with the long-term CDI being formulated by use of the self-calibrating Palmer Hydrology Drought Index (sc-PHDI), the 6-, 12-, 18- and 24-month SPEI, the Standardized Streamflow Index (SSI), the SMI. The sc-PDSI, the PHDI, the ZIND, the SPEI on a monthly time scale were calculated based on the monthly air temperature and precipitation, and the monthly SMI and SSI were computed based on the simulated soil moisture and runoff by the distributed Xinanjiang model. The thresholds of the short-term/long-term CDI were determined according to frequency statistics of different drought indices. Finally, the feasibility of the two CDIs was investigated against the scPDSI, the SPEI and the historical drought records. The results revealed that the short-term/long-term CDI could capture the onset, severity, persistence of drought events very well with the former being better at identifying the dynamic evolution of drought condition while the latter better at judging the changing trend of drought over a long time period.

  13. Real-time forecast of the 2005 and 2007 summer severe floods in the Huaihe River Basin of China

    NASA Astrophysics Data System (ADS)

    Lin, Charles A.; Wen, Lei; Lu, Guihua; Wu, Zhiyong; Zhang, Jianyun; Yang, Yang; Zhu, Yufei; Tong, Linying

    2010-02-01

    SummaryWe have developed a one-way coupled hydro-meteorological modeling system consisting of the mesoscale atmospheric model MC2 (Canadian Mesoscale Compressible Community), the Chinese Xinanjiang hydrological model for runoff generation, a flow routing model, and a module for acquiring real-time gauge precipitation. The system had been successfully tested in a hindcast mode using a total of 18 meteorological cases from 1998 and 2003 in the Huaihe River Basin (HRB; 270,000 km 2) of China, and has been used to generate daily precipitation and flood forecasts in real-time for the 2005, 2006 and 2007 flooding season over the Wangjiaba sub-basin (30,500 km 2), part of the HRB. We run MC2 daily to produce a 96-h precipitation forecast, and then use the combined gauge-model precipitation to drive the hydrological model off-line to forecast the hydrograph at the Wangjiaba Station that is at the outlet of the Wangjiaba sub-basin. We examine the daily forecasts for the two most severe flood events encountered in the past three flooding seasons. The two events occurred in July 4-15, 2005 and June 30-July 25, 2007, which necessitated the use of several flood spillway and flood detention areas along the mainstream of the Huaihe River. A total of 19 daily 96-h precipitation forecasts from the two events are examined. The 19 daily forecasts with different lead times compare reasonably well with observations, although the skill as measured by the MC2 relative error and the MC2 forecast success rate is uneven over a 4-day forecast period. MC2 can better forecast the 96-h accumulation compared to 24-h amounts. We also analyze 10 daily hydrograph forecasts from the two events. The flood peak of the two events at the Wangjiaba Station is predicted well in both timing and intensity with a lead time beyond four days, although the quality of our daily hydrograph forecasts as measured by the relative percentage error of the forecast peak discharge and the Nash-Sutcliffe coefficient is

  14. Geochemistry of sediments from the Huaibei Plain (east China): Implications for provenance, weathering, and invasion of the Yellow River into the Huaihe River

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Qin, Xiaoguang; Liu, Jiaqi; Sun, Chunqing; Mu, Yan; Gao, Jinliang; Guo, Wenfeng; An, Shikai; Lu, Chunhui

    2016-05-01

    The sediments of the Huaibei Plain in semi-humid mid-eastern China represent valuable geological records with respect to eolian-fluvial interactions, depositional environments, and climate change in this region. Provenance and weathering conditions are often reconstructed using sedimentary geochemistry methods. In this study, an 8-m core from Huainan and a set of loess samples from northern and southern China were analyzed for major, trace, and rare earth elements (REEs). Results were compared to determine the samples' provenance. The major, trace, rare earth elements contents, and grain size distribution were found to fluctuate widely in the 2-8 m section of the Huainan core and more narrowly closer to the surface (0-2 m). This suggests a provenance shift at a depth of 2 m. The TiO2/Al2O3, SiO2/Al2O3, Th/Nb, La/Nb values and REE patterns in the upper core (0-2 m) are similar to those found in samples from the Chinese Loess Plateau (CLP). These results suggest that the CLP in northern China is likely to be the primary origin of the upper part (0-2 m) of the Huainan core. Compared with CLP samples, the upper part of the Huainan core exhibits lower K2O/Al2O3 values and higher chemical alteration indices. This is indicative of the material's substantial weathering during transportation and re-deposition and implies that these sediments could reasonably be classified as typical recycled loess. The sediments may have been transported from the CLP to Huainan as Yellow River flood events, probably during the last deglaciation (∼13.2 ka) as a result of increased precipitation, along with glacier and snow melt in the upper reaches of the Yellow River catchment during this period. This suggests that the Yellow River may have migrated into the Huaihe River catchment much earlier than the earliest historical records (361 BCE) suggest. The implications of this would be profound with respect to Chinese history.

  15. Concentrations of organochlorine pesticides in umbilical cord blood and related lifestyle and dietary intake factors among pregnant women of the Huaihe River Basin in China.

    PubMed

    Luo, Dan; Pu, Yabing; Tian, Haoyuan; Cheng, Juan; Zhou, Tingting; Tao, Yun; Yuan, Jing; Sun, Xin; Mei, Surong

    2016-01-01

    Organochlorine pesticides (OCPs), one of the persistent organic pollutants (POPs) with highly lipophilic properties, long half-lives, and persistence in the environment, are prevalent in the environment even though they have been banned for >30years. We aimed to investigate the current OCP exposure levels in cord blood from healthy pregnant women residing in the Huaihe River Basin, China, and examined the association between OCP levels and dietary habits and lifestyle factors. In this study, we measured the exposure levels of 17 OCPs in the umbilical cord blood from 999 healthy pregnant women; we also administered 1000 self-reported questionnaires regarding the general characteristics and dietary habits of those women. Our results showed that ρ,ρ'-DDE, ρ,ρ'-DDT, aldrin, dieldrin, and methoxychlor, which had higher measured concentrations (2.01±1.89, 4.31±5.68, 7.29±8.74, 5.27±7.65, and 0.98±1.42ng/mL, respectively) and detection frequencies (99.69%, 100.00%, 81.79%, 75.00%, and 74.49%, respectively), were the predominant OCPs in cord blood, and the higher levels of DDTs, aldrin, dieldrin, and methoxychlor were mainly due to recent use. In addition, most of the HCHs in cord blood were derived not only from historical use of technical HCH, but also from the additional use of lindane. In addition, we found that the education level of the pregnant women and monthly household income were positively correlated with OCP levels, particularly ρ,ρ'-DDE, aldrin, and dieldrin. Furthermore, the consumption of red meat (pork, beef, and lamb), fish, and bean products may be an important contributing factor to the increased concentrations of OCPs in cord blood, while the intake of poultry and pickles was negatively correlated with aldrin level. This study is the first to provide adequate data on current OCP exposure levels in cord blood from pregnant women in the Huaihe River Basin.

  16. Concentrations of organochlorine pesticides in umbilical cord blood and related lifestyle and dietary intake factors among pregnant women of the Huaihe River Basin in China.

    PubMed

    Luo, Dan; Pu, Yabing; Tian, Haoyuan; Cheng, Juan; Zhou, Tingting; Tao, Yun; Yuan, Jing; Sun, Xin; Mei, Surong

    2016-01-01

    Organochlorine pesticides (OCPs), one of the persistent organic pollutants (POPs) with highly lipophilic properties, long half-lives, and persistence in the environment, are prevalent in the environment even though they have been banned for >30years. We aimed to investigate the current OCP exposure levels in cord blood from healthy pregnant women residing in the Huaihe River Basin, China, and examined the association between OCP levels and dietary habits and lifestyle factors. In this study, we measured the exposure levels of 17 OCPs in the umbilical cord blood from 999 healthy pregnant women; we also administered 1000 self-reported questionnaires regarding the general characteristics and dietary habits of those women. Our results showed that ρ,ρ'-DDE, ρ,ρ'-DDT, aldrin, dieldrin, and methoxychlor, which had higher measured concentrations (2.01±1.89, 4.31±5.68, 7.29±8.74, 5.27±7.65, and 0.98±1.42ng/mL, respectively) and detection frequencies (99.69%, 100.00%, 81.79%, 75.00%, and 74.49%, respectively), were the predominant OCPs in cord blood, and the higher levels of DDTs, aldrin, dieldrin, and methoxychlor were mainly due to recent use. In addition, most of the HCHs in cord blood were derived not only from historical use of technical HCH, but also from the additional use of lindane. In addition, we found that the education level of the pregnant women and monthly household income were positively correlated with OCP levels, particularly ρ,ρ'-DDE, aldrin, and dieldrin. Furthermore, the consumption of red meat (pork, beef, and lamb), fish, and bean products may be an important contributing factor to the increased concentrations of OCPs in cord blood, while the intake of poultry and pickles was negatively correlated with aldrin level. This study is the first to provide adequate data on current OCP exposure levels in cord blood from pregnant women in the Huaihe River Basin. PMID:27123771

  17. Out-of-phase decadal changes in boreal summer rainfall between Yellow-Huaihe River Valley and southern China around 2002/2003

    NASA Astrophysics Data System (ADS)

    Ha, Yao; Zhong, Zhong; Chen, Haishan; Hu, Yijia

    2016-07-01

    This study investigates the decadal variability of rainfall over China in boreal summer (June-August) since the early 1990s. Results show that the rainfall experiences an abrupt decadal change at around 2002/2003. The decadal change is statistically significant and characterized by an out-of-phase pattern between southern China (SC) and the Yellow-Huaihe River Valley (YHRV). The rainfall over SC decreases during the decade 2003-2012 compared to that in the preceding decade 1993-2002. A simultaneous decadal increase in rainfall has occurred over the YHRV. Meanwhile, a significant sea surface temperature warming appears over the western Pacific Ocean and the northern Indian Ocean after 2002 on the decadal time scale. Further analysis reveals that enhanced convections are activated over the tropical regions between 130°E and 160°E and west of 80°E due to the SST anomalies, which induce the dry air in an area of anomalous subsidence located over SC and the northern South China Sea (SCS) via zonal circulation. Accompanied by the anomalous descending flow over the northern SCS, tropical cyclone (TC) activities in the SCS also experience a concurrent decadal reduction. The decrease in landfall TCs contributes to the decadal decrease in SC rainfall since 2003. Corresponding to the anomalous descending motion that is dominant south of 30°N, an anomalous moist ascending flow develops over the YHRV at around 35°N. Meanwhile, the western Pacific subtropical high becomes stronger and extends further westward during 2003-2012, leading to enhanced moisture transport by the southwesterly in the northwestern flank of subtropical high. As a result, more precipitation occurs over the YHRV. The above analysis has revealed the physical-dynamical processes involved in the decadal changes in rainfall over China. The mechanisms behind the out-of-phase pattern of rainfall changes between SC and the YHRV that occurred at 2002/2003 are explored.

  18. Novel early flood warning in the Huaihe River basin in east-central China using the TIGGE database

    NASA Astrophysics Data System (ADS)

    He, Y.; Cloke, H.; Li, Z.; Wetterhall, F.; Pappenberger, F.

    2009-04-01

    Flooding is a wide spread and devastating natural disaster worldwide. Floods that took place in the last decade in China were ranked the worst amongst recorded floods worldwide in terms of the number of human fatalities and economic losses (Munich Re-Insurance). Rapid economic development and population expansion into low lying flood plains has worsened the situation. The last decade has seen an increase in flood preparedness across all levels of society in China. Current conventional flood prediction systems in China are neither suited to the perceptible climate variability nor the rapid pace of urbanization sweeping the country. Flood prediction systems from short-term (a few hours) to medium-term (a few days) need to be revisited and adapted to changing socio-economic and hydro-climatic realities. The latest technology requires implementation of multiple numerical weather prediction systems. The availability of a number of global ensemble weather prediction systems through the ‘THORPEX Interactive Grand Global Ensemble' (TIGGE) offers a good opportunity for an effective state-of-the-art early forecasting system. A prototype of a Novel Flood Early Warning System (NEWS) using the TIGGE database is tested in the Huai River basin located in east-central China. It is the first early flood warning system in China that uses the massive TIGGE database cascaded with river catchment models, the Xinanjiang model and a 1-D hydraulic model, to predict river discharge and flood inundation. Results from selected flood events will be presented.

  19. Contrasts of atmospheric circulation and associated tropical convection between Huaihe River valley and Yangtze River valley mei-yu flooding

    NASA Astrophysics Data System (ADS)

    Hong, Jieli; Liu, Yimin

    2012-07-01

    The significant differences of atmospheric circulation between flooding in the Huaihe and Yangtze River valleys during early mei-yu (i.e., the East Asian rainy season in June) and the related tropical convection were investigated. During the both flooding cases, although the geopotential height anomalies always exhibit equivalent barotropic structures in middle to high latitudes at middle and upper troposphere, the phase of the Rossby wave train is different over Eurasian continent. During flooding in the Huaihe River valley, only one single blocking anticyclone is located over Baikal Lake. In contrast, during flooding in the Yangtze River valley, there are two blocking anticyclones. One is over the Ural Mountains and the other is over Northeast Asia. In the lower troposphere a positive geopotential height anomaly is located at the western ridge of subtropical anticyclone over Western Pacific (SAWP) in both flooding cases, but the location of the height anomaly is much farther north and west during the Huaihe River mei-yu flooding. Furthermore, abnormal rainfall in the Huaihe River valley and the regions north of it in China is closely linked with the latent heating anomaly over the Arabian Sea and Indian peninsula. However, the rainfall in the Yangtze River valley and the regions to its south in China is strongly related to the convection over the western tropical Pacific. Numerical experiments demonstrated that the enhanced latent heating over the Arabian Sea and Indian peninsula causes water vapor convergence in the region south of Tibetan Plateau and in the Huaihe River valley extending to Japan Sea with enhanced precipitation; and vapor divergence over the Yangtze River valley and the regions to its south with deficient precipitation. While the weakened convection in the tropical West Pacific results in moisture converging over the Yangtze River and the region to its south, along with abundant rainfall.

  20. Species and biogeochemical cycles of organic phosphorus in sediments from a river with different aquatic plants located in Huaihe River Watershed, China.

    PubMed

    Yuan, He Zhong; Pan, Wei; Ren, Li Jun; Liu, Eeng Feng; Shen, Ji; Geng, Qi Fang; An, Shu Qing

    2015-01-01

    The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution 31P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum>Typha orientalis>Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.

  1. [Spatial heterogeneity and classified control of agricultural non-point source pollution in Huaihe River Basin].

    PubMed

    Zhou, Liang; Xu, Jian-Gang; Sun, Dong-Qi; Ni, Tian-Hua

    2013-02-01

    Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74 x 10(4) t, 66.49 x 10(4) t, 8.74 x 10(4) t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t.hm-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.

  2. Features of the short-term position variation of the west Pacific subtropical high during the torrential rain in Yangtze-Huaihe river valley and its possible cause

    NASA Astrophysics Data System (ADS)

    Guan, Zhaoyong; Yu, Bo; Wang, Lijuan; He, Jielin; Zeng, Gang

    2009-08-01

    By using the NCEP/NCAR daily reanalysis data, CMAP precipitation data , daily precipitation data of 740 stations in China and some remote sensing data, features of the short-term position variation of the west Pacific subtropical high(WPSH) during the torrential rain in Yangtze-Huaihe river valley and its possible cause are analyzed. Results show that the short-term position variation of WPSH is closely associated with the diabatic heating. During the torrential rain period, the apparent heating source and apparent moisture sink are exceptionally strong over Yangtze-Huaihe river valley( on the northwest side of WPSH )and the Bay of Bengal (to the west of WPSH). Based on the complete form of vertical vorticity tendency equation, it is found that the heating field over Yangtze-Huaihe river valley during the torrential rain period, which is in favor of the increase of cyclonic vorticity on the north side of WPSH, is unfavorable to the WPSH moving northward. And the heat source over the Bay of Bengal ,which is in favor of the increase of anti-cyclonic vorticity on the west of WPSH, may induce the westward extension of WPSH.

  3. Evaluation of the latest satellite-gauge precipitation products and their hydrologic applications over the Huaihe River basin

    NASA Astrophysics Data System (ADS)

    Sun, Ruochen; Yuan, Huiling; Liu, Xiaoli; Jiang, Xiaoman

    2016-05-01

    Satellite-gauge quantitative precipitation estimate (QPE) products may reduce the errors in near real-time satellite precipitation estimates by combining rain gauge data, which provides great potential to hydrometeorological applications. This study aims to comprehensively evaluate four of the latest satellite-gauge QPEs, including NASA's Tropical Rainfall Measuring Mission (TRMM) 3B42V7 product, NOAA's Climate Prediction Center (CPC) MORPHing technique (CMORPH) bias-corrected product (CMORPH CRT), CMORPH satellite-gauge merged product (CMORPH BLD) and CMORPH satellite-gauge merged product developed at the National Meteorological Information Center (NMIC) of the China Meteorological Administration (CMA) (CMORPH CMA). These four satellite-gauge QPEs are statistically evaluated over the Huaihe River basin during 2003-2012 and applied into the distributed Variable Infiltration Capacity (VIC) model to assess hydrologic utilities. Compared to the China Gauge-based Daily Precipitation Analysis (CGDPA) newly developed at CMA/NMIC, the four satellite-gauge QPEs generally depict the spatial distribution well, with the underestimation in the southern mountains and overestimation in the northern plain of the Huaihe River basin. Specifically, both TRMM and CMORPH CRT adopt simple gauge adjustment algorithms and exhibit relatively poor performance, with evidently deteriorated quality in winter. In contrast, the probability density function-optimal interpolation (PDF-OI) gauge adjustment procedure has been applied in CMORPH BLD and CMORPH CMA, resulting in higher quality and more stable performance. CMORPH CMA further benefits from a merged dense gauge observation network and outperforms the other QPEs with significant improvements in rainfall amount and spatial/temporal distributions. Due to the insufficient gauge observations in the merging process, CMORPH BLD features the similar error characteristics of CMORPH CRT with a positive bias of light precipitation and a negative

  4. Study on quantile estimates of extreme precipitation and their spatiotemporal consistency adjustment over the Huaihe River basin

    NASA Astrophysics Data System (ADS)

    Shao, Yuehong; Wu, Junmei; Li, Min

    2016-09-01

    The quantile estimates and spatiotemporal consistency of extreme precipitation are studied by regional linear frequency analysis for Huaihe River basin in China. Firstly, the study area can be categorized into six homogeneous regions by using cluster analysis, heterogeneity measure, and discordancy measure. In the next step, we determine the optimum distribution for each homogeneous region by using two criteria of Monte Carlo simulations and the root-mean-square error (RMSE) of the sample L-moments. A diagram of L-moments ratio is used to further judge and validate the optimum distribution. The generalized extreme value (GEV), generalized normal (GNO), and generalized logistic (GLO) for 24-h duration are determined to be the more appropriate distribution based on the two criteria, L-moments ratio plot, and the tail thickness of curve in adjacent regions. A summary assessment can provide the more reasonable distribution, which avoids arbitrary results from single test. An important practical element of this study that was missing from previous works is the quantile spatiotemporal consistency analysis, which helps identify non-monotonicity among quantiles at different durations and reduces the gradient of estimates in the adjacent regions. Abnormality and spatial discontinuation can be removed by distributing the surplus of the ratio and twice different interpolation. A complete set of spatiotemporal consistent quantile estimates for various duration (24 h, 3 days, 5 days, and 7 days) and return periods (from 2 to 1000 years) can be obtained by using the abovementioned method in the study area, which are in the agreement with the observed precipitation extremes. It will provide important basis for hydrometeorological research, which is of significant scientific and practical merit.

  5. Increased lead and cadmium tolerance of Typha angustifolia from Huaihe River is associated with enhanced phytochelatin synthesis and improved antioxidative capacity.

    PubMed

    Liu, Yunlei; Chen, Jian; Lu, Shaonan; Yang, Libo; Qian, Jiazhong; Cao, Shuqing

    2016-11-01

    Heavy metal contamination of water is an increasing environmental problem worldwide, and the use of aquatic plants for phytoremediation of heavy metal pollution has become an important subject of research. One key to successful phytoremediation is the identification of plants that are efficient at sequestering heavy metals. In this study, we examined the growth and heavy metal accumulation of Typha angustifolia and compared growth characteristics and tolerance mechanisms in plants from the Huaihe and Chaohu Rivers irrigated with different concentrations of lead (Pb) and cadmium (Cd). T. angustifolia from Huaihe River showed enhanced tolerance and accumulation of Pb and Cd and had greater biomass and more vigorous growth than the ecotype from Chaohu River. In addition, higher phytochelatin (PC) content and significantly higher superoxide dismutase and catalase activities were detected in T. angustifolia from Huaihe River than in T. angustifolia from Chaohu River. These findings suggest that high Pb and Cd accumulation and tolerance in T. angustifolia from Chaohu River is associated with its higher PC synthesis and better antioxidative capacity, and that the Huaihe ecotype of T. angustifolia might also be an efficient species for phytoremediation of Pb and Cd in water contaminated by heavy metals. PMID:26959972

  6. Warm season heavy rainfall events over the Huaihe River Valley and their linkage with wintertime thermal condition of the tropical oceans

    NASA Astrophysics Data System (ADS)

    Li, Laifang; Li, Wenhong; Tang, Qiuhong; Zhang, Pengfei; Liu, Yimin

    2016-01-01

    Warm season heavy rainfall events over the Huaihe River Valley (HRV) of China are amongst the top causes of agriculture and economic loss in this region. Thus, there is a pressing need for accurate seasonal prediction of HRV heavy rainfall events. This study improves the seasonal prediction of HRV heavy rainfall by implementing a novel rainfall framework, which overcomes the limitation of traditional probability models and advances the statistical inference on HRV heavy rainfall events. The framework is built on a three-cluster Normal mixture model, whose distribution parameters are sampled using Bayesian inference and Markov Chain Monte Carlo algorithm. The three rainfall clusters reflect probability behaviors of light, moderate, and heavy rainfall, respectively. Our analysis indicates that heavy rainfall events make the largest contribution to the total amount of seasonal precipitation. Furthermore, the interannual variation of summer precipitation is attributable to the variation of heavy rainfall frequency over the HRV. The heavy rainfall frequency, in turn, is influenced by sea surface temperature anomalies (SSTAs) over the north Indian Ocean, equatorial western Pacific, and the tropical Atlantic. The tropical SSTAs modulate the HRV heavy rainfall events by influencing atmospheric circulation favorable for the onset and maintenance of heavy rainfall events. Occurring 5 months prior to the summer season, these tropical SSTAs provide potential sources of prediction skill for heavy rainfall events over the HRV. Using these preceding SSTA signals, we show that the support vector machine algorithm can predict HRV heavy rainfall satisfactorily. The improved prediction skill has important implication for the nation's disaster early warning system.

  7. Phosphorus release: A biogeochemical insight from a restored lakeside wetland in the Yangtze-huaihe region, China.

    PubMed

    Zhou, Xiaoling; Shan, Baoqing; Zhang, Hong

    2010-01-01

    The heavy intensification of agriculture in East China since the 1980s caused the decrease of lake area and water storage capacity with impediment of regulation, lake eutrophication and frequent floods. Many restoration projects have been conducted. However, the knowledge of biogeochemical factors that drive nutrient cycles during the early stage of restoration is still limited. We studied the effect of the remediation of a patch of near-shore shallow wetland on the northern bank of Chaohu Lake in the Yangtze-Huaihe region, China, which was used as rice paddy for many years, on the behavior of phosphorus. Redox potential (ORP), temperature and dissolved oxygen were monitored in situ from May 2006 to November 2007. Samples of soil pore water were collected during this time for the determination of different forms of iron and phosphorus. ORP showed a clear transition of the wetland soil from an oxidized state in winter to a reduced state in summer. The decrease of ORP correlated with the release of large amounts of Fe and P. The maxima of total dissolved Fe and total dissolved P in the summer of the second year were (13.8 +/- 6.8) mg/L and (0.88 +/- 0.27) mg/L, respectively. It is worth noticing that P concentration far exceeded the critical value of lake eutrophication (0.02 mg/L). The pressure of P release to the adjacent lake during the first two years of wetland restoration from rice fields should be taken into account by environmental policy makers.

  8. Spectral characteristics of precipitating clouds during the Meiyu over the Yangtze-Huaihe River Valley from merged TRMM precipitation radar and visible/infrared scanner data

    NASA Astrophysics Data System (ADS)

    Yang, Yuan-Jian; Fu, Yun-Fei; Chen, Feng-Jiao; Zheng, Xiao-Yi; Chen, Yi-Lun

    2014-11-01

    As the similar cross track scanning mode of the measurements of Tropical Rainfall Measuring Mission's (TRMM) Precipitation Radar (PR) and visible and infrared scanner (VIRS) results in near instantaneous synchronization in observing the same target, it is feasible to jointly use these two measurements to explore exactly the spectral characteristics of precipitating clouds (PCs). Meanwhile, it will effectively improve and extend the abilities to identify PCs using visible/infrared (VIR) measurements, because VIR sensors can be loaded aboard geostationary satellites with the opportunity of high sampling frequency. In this paper, PR and VIRS onboard TRMM are respectively used to capture PCs and identify their spectral signals during the Meiyu over the Yangtze-Huaihe River Valley from 1998 to 2007. Visible/infrared signals for PCs, which are the reflectance at 0.63μm and 1.6μm (referred to as RF1 and RF2, respectively), and the equivalent brightness temperature of a blackbody at 3.7μm, 10.8 μm and 12.0μm (referred to as TB3, TB4 and TB5, respectively), were derived by TRMM VIRS. Firstly, characteristics of rain rate, rain top and vertical profiles for stratiform and convective precipitations are investigated during the Meiyu periods. Moreover, VIRS individual-channel signals, and multi-channel indices for PCs of the Meiyu are evaluated quantitatively. Finally, revealed by long-term mean values, the differences of spectral signals between stratiform and convective PCs and their relationships with surface rain rates are explored.

  9. 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.

  10. Rehabilitating China's largest inland river.

    PubMed

    Li, Yiqing; Chen, Yaning; Zhang, Yaoqi; Xia, Yang

    2009-06-01

    Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica, which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20-45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources.

  11. Rehabilitating China's largest inland river.

    PubMed

    Li, Yiqing; Chen, Yaning; Zhang, Yaoqi; Xia, Yang

    2009-06-01

    Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica, which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20-45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources. PMID:22748091

  12. Research on environmental flow in Huai River Basin, China

    NASA Astrophysics Data System (ADS)

    Liu, H. C.; Shui, Y.; Li, L. H.; Cao, N.; Yu, G. Y.; Liu, J.

    2016-08-01

    The estimation methods for environmental flow were discussed in this paper. Based on the comparative analysis of calculation methods of environmental flow, a "Huaihe Method" was proposed, which consists of the hydrological estimation of the minimum environmental flow with validation by the requirment space for fish. The minimum environmental flows of the important control sections in main stream and tributaries in the Huai River basin are estimated. The recommened minimum environmental flow has been adopted in the water resources planning, which provided reference for rational allocation of environmental flow, water resources usage, and sustainable development for the local society.

  13. Detecting changes in future precipitation extremes over eight river basins in China using RegCM4 downscaling

    NASA Astrophysics Data System (ADS)

    Qin, Peihua; Xie, Zhenghui

    2016-06-01

    To detect the frequency and intensity of precipitation extremes in China for the middle 21st century, simulations were conducted with the regional climate model RegCM4 forced by the global climate model GFDL_ESM2M under the middle emission scenario (RCP4.5). Compared with observed precipitation extremes for the reference period from 1982 to 2001, RegCM4 generally performed better in most river basins of China relative to GFDL. In the future period 2032-2051, more wet extremes will occur relative to the present period in most study areas, especially in southeast China while significantly less dry extremes will occur in arid and semiarid areas in northwest China. In contrast, areas in northwest China showed an increase in the trend of dry extremes (CDD) and a decrease in the trend of wet extremes (R95p and Rx5day), which might result in more drought in the future. Finally, we discuss in detail the possible reason of these processes, such as zonal wind, vertical wind, and water vapor. In the Huaihe river basin (HU), reduced south winds in summer (June-August) and a decrease of the upward vertical p velocity cause less future precipitation and might lead to changes of extreme events. We also completed correlation analysis between the precipitation extreme indices and the climate factors and found that the precipitation extremes were more sensitive to the annual and seasonal mean precipitation, total water vapor, and upward vertical wind relative to the geopotential height and 2 m temperature over most river basins in China. Perhaps the changes of some wet extremes could be verified partly through changes of annual precipitation due to their high consistence.

  14. [Multi-spectroscopy applied to study on a late neolithic colored stone from Yuhui Site in Huaihe Basin].

    PubMed

    Wang, Hai-gang; Jin, Zheng-yao; Xie, Zhi; Fan, An-chuan; Yan, Li-feng; Zhu, Bing-quan; Wang, Ji-huai

    2013-09-01

    The unearthing of a large number of red-yellow colored stones in Yuhui Site, Bengbu city, Anhui province of China, which was the only site of Longshan culture appointed by "Origin of the Chinese Civilization Project" in the Huaihe River basin, has drawn a widespread attention in archaeology. The present research was undertaken to examine elements, mineral composition and thermal history of one red-yellow color stone in different positions, classified according to specialized colors, by means of synchrotron radiation X-ray fluorescence (SR-XRF), X-ray diffraction (XRD), laser Raman spectroscopy (LRS), electron probe micro-analysis (EPMA) and thermoluminescence (TL). The results show that the main body of the color stone is limonite with a large amount of quartz inclusion. The yellow substances on the surface layer of the color stone were identified as goethite (alpha-FeOOH), and the red ones as red ochre (alpha-Fe2O3+clay+silica). The internal yellow brown substances inside the stone are mainly aphanitic goethite with a number of chromites and manganese dioxide, and also with small quantity of barite and bismuth. And the color stones are without historical firing treatment. These kinds of special polymetallic ores with unique nature and complex geologic history, which were unearthed in the late neolithic site with large numbers, may be closely related to some kind of primitive religious beliefs and special sacrificial practices. PMID:24369621

  15. Simultaneous assessments of occurrence, ecological, human health, and organoleptic hazards for 77 VOCs in typical drinking water sources from 5 major river basins, China.

    PubMed

    Chen, Xichao; Luo, Qian; Wang, Donghong; Gao, Jijun; Wei, Zi; Wang, Zijian; Zhou, Huaidong; Mazumder, Asit

    2015-11-01

    Owing to the growing public awareness on the safety and aesthetics in water sources, more attention has been given to the adverse effects of volatile organic compounds (VOCs) on aquatic organisms and human beings. In this study, 77 target VOCs (including 54 common VOCs, 13 carbonyl compounds, and 10 taste and odor compounds) were detected in typical drinking water sources from 5 major river basins (the Yangtze, the Huaihe, the Yellow, the Haihe and the Liaohe River basins) and their occurrences were characterized. The ecological, human health, and olfactory assessments were performed to assess the major hazards in source water. The investigation showed that there existed potential ecological risks (1.30 × 10 ≤ RQtotals ≤ 8.99 × 10) but little human health risks (6.84 × 10(-7) ≤ RQtotals ≤ 4.24 × 10(-4)) by VOCs, while that odor problems occurred extensively. The priority contaminants in drinking water sources of China were also listed based on the present assessment criteria.

  16. [Health assessment of river ecosystem in Haihe River Basin, China].

    PubMed

    Hao, Li-Xia; Sun, Ran-Hao; Chen, Li-Ding

    2014-10-01

    With the development of economy, the health of river ecosystem is severely threatened because of the increasing effects of human activities on river ecosystem. In this paper, the authors assessed the river ecosystem health in aspects of chemical integrity and biological integrity, using the criterion in water quality, nutrient, and benthic macroinvertebrates of 73 samples in Haihe River Basin. The research showed that the health condition of river ecosystem in Haihe River Basin was bad overall since the health situation of 72. 6% of the samples was "extremely bad". At the same time, the health situation in Haihe River Basin exhibited obvious regional gathering effect. We also found that the river water quality was closely related to human activities, and the eutrophication trend of water body was evident in Haihe River Basin. The biodiversity of the benthic animal was low and lack of clean species in the basin. The indicators such as ammonia nitrogen, total nitrogen and total phosphorus were the key factors that affected the river ecosystem health in Haihe River Basin, so the government should start to curb the deterioration of river ecosystem health by controlling these nutrients indicators. For river ecosystem health assessment, the multi-factors comprehensive evaluation method was superior to single-factor method.

  17. Study on river regulation measures of dried-up rivers of Haihe River basin, China.

    PubMed

    Peng, Jing; Li, Shaoming; Qi, Lan

    2013-01-01

    In recent years, the ecological environment of plain rivers within Haihe River basin is questionable because of severe water shortages. Most of the rivers dry up regularly and it is therefore necessary to take measures to improve the river ecological environment. Meanwhile, flood control is the principal function for most of the dried-up rivers, so river regulation works for flood control also should be undertaken. In this paper, some measures of river regulation were selected applied to the Haihe River basin, taking these measures not only ensure the river security but also realize its ecological benefit. Examples of the application of selected measures for the representative rivers, Yongding River and Hutuo River, both located within the Haihe River basin, are also assessed. These measures provide practical solutions to ecological and flood control problems of dried-up rivers, are generic in nature, and could therefore be applied to other same type rivers.

  18. Assessing impact of urbanization on river water quality in the Pearl River Delta Economic Zone, China.

    PubMed

    Ouyang, Tingping; Zhu, Zhaoyu; Kuang, Yaoqiu

    2006-09-01

    The Pearl River Delta Economic Zone is one of the most developed regions in China. It has been undergoing a rapid urbanization since the reformation and opening of China in 1978. This process plays a significant impact on the urban environment, particularly river water quality. The main goal of this present study is to assess the impact of urban activities especially urbanization on river water quality for the study area. Some Landsat TM images from 2000 were used to map the areas for different pollution levels of urban river sections for the study area. In addition, an improved equalized synthetic pollution index method was utilized to assess the field analytical results. The results indicate that there is a positive correlation between the rapidity of urbanization and the pollution levels of urban river water. Compared to the rural river water, urban river water was polluted more seriously. During the urban development process, urbanization and urban activities had a significant negative impact on the river water quality.

  19. 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.

  20. 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

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

    PubMed

    Ding, Yuekui; Shan, Baoqing; Zhao, Yu

    2015-09-01

    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

  2. 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...

  3. 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

  4. Spatial and seasonal characteristics of river water chemistry in the Taizi River in Northeast China.

    PubMed

    Bu, Hongmei; Meng, Wei; Zhang, Yuan

    2014-06-01

    Anthropogenic activities have led to water quality deterioration in many parts of the world, especially in Northeast China. The current work investigated the spatiotemporal variations of water quality in the Taizi River by multivariate statistical analysis of data from the 67 sampling sites in the mainstream and major tributaries of the river during dry and rainy seasons. One-way analysis of variance indicated that the 20 measured variables (except pH, 5-day biological oxygen demand, permanganate index, and chloride, orthophosphate, and total phosphorus concentrations) showed significant seasonal (p ≤ 0.05) and spatial (p < 0.05) variations among the mainstream and major tributaries of the river. Hierarchical cluster analysis of data from the different seasons classified the mainstream and tributaries of the river into three clusters, namely, less, moderately, and highly polluted clusters. Factor analysis extracted five factors from data in the different seasons, which accounted for the high percentage of the total variance and reflected the integrated characteristics of water chemistry, organic pollution, phosphorous pollution, denitrification effect, and nitrogen pollution. The results indicate that river pollution in Northeast China was mainly from natural and/or anthropogenic sources, e.g., rainfall, domestic wastewater, agricultural runoff, and industrial discharge.

  5. Spatial and seasonal characteristics of river water chemistry in the Taizi River in Northeast China.

    PubMed

    Bu, Hongmei; Meng, Wei; Zhang, Yuan

    2014-06-01

    Anthropogenic activities have led to water quality deterioration in many parts of the world, especially in Northeast China. The current work investigated the spatiotemporal variations of water quality in the Taizi River by multivariate statistical analysis of data from the 67 sampling sites in the mainstream and major tributaries of the river during dry and rainy seasons. One-way analysis of variance indicated that the 20 measured variables (except pH, 5-day biological oxygen demand, permanganate index, and chloride, orthophosphate, and total phosphorus concentrations) showed significant seasonal (p ≤ 0.05) and spatial (p < 0.05) variations among the mainstream and major tributaries of the river. Hierarchical cluster analysis of data from the different seasons classified the mainstream and tributaries of the river into three clusters, namely, less, moderately, and highly polluted clusters. Factor analysis extracted five factors from data in the different seasons, which accounted for the high percentage of the total variance and reflected the integrated characteristics of water chemistry, organic pollution, phosphorous pollution, denitrification effect, and nitrogen pollution. The results indicate that river pollution in Northeast China was mainly from natural and/or anthropogenic sources, e.g., rainfall, domestic wastewater, agricultural runoff, and industrial discharge. PMID:24477615

  6. Occurrence and distribution of hexabromocyclododecane in sediments from seven major river drainage basins in China.

    PubMed

    Li, Honghua; Shang, Hongtao; Wang, Pu; Wang, Yawei; Zhang, Haidong; Zhang, Qinghua; Jiang, Guibin

    2013-01-01

    The concentrations and geographical distribution of hexabromocyclododecane (HBCD) were investigated in 37 composite surface sediments from seven major river drainage basins in China, including Yangtze River, Yellow River, Pearl River, Liaohe River, Haihe River, Tarim River and Ertix River. The detection frequency of HBCD was 54%, with the concentrations ranged from below limit of detection (LOD) to 206 ng/g dry weight. In general, the geographical distribution showed increasing trends from the upper reaches to the lower reaches of the rivers and from North China to Southeast China. Compared to other regions in the world, the average concentration of HBCD in sediments from Yangtze River drainage basin was at relatively high level, whereas those from other six river drainage basins were at lower or similar level. The highest HBCD concentration in sediment from Yangtze River Delta and the highest detection frequency of HBCD in Pearl River drainage basins suggested that the industrial and urban activities could evidently affect the HBCD distribution. HBCD diastereoisomer profiles showed that gamma-HBCD dominated in most of the sediment samples, followed by alpha- and beta-HBCD, which was consistent with those in the commercial HBCD mixtures. Further risk assessment reflected that the average inventories of HBCD were 18.3, 5.87, 3.92, 2.50, 1.77 ng/cm2 in sediments from Pearl River, Haihe River, Tarim River, Yellow River and Yangtze River, respectively. PMID:23586301

  7. Occurrence and distribution of hexabromocyclododecane in sediments from seven major river drainage basins in China.

    PubMed

    Li, Honghua; Shang, Hongtao; Wang, Pu; Wang, Yawei; Zhang, Haidong; Zhang, Qinghua; Jiang, Guibin

    2013-01-01

    The concentrations and geographical distribution of hexabromocyclododecane (HBCD) were investigated in 37 composite surface sediments from seven major river drainage basins in China, including Yangtze River, Yellow River, Pearl River, Liaohe River, Haihe River, Tarim River and Ertix River. The detection frequency of HBCD was 54%, with the concentrations ranged from below limit of detection (LOD) to 206 ng/g dry weight. In general, the geographical distribution showed increasing trends from the upper reaches to the lower reaches of the rivers and from North China to Southeast China. Compared to other regions in the world, the average concentration of HBCD in sediments from Yangtze River drainage basin was at relatively high level, whereas those from other six river drainage basins were at lower or similar level. The highest HBCD concentration in sediment from Yangtze River Delta and the highest detection frequency of HBCD in Pearl River drainage basins suggested that the industrial and urban activities could evidently affect the HBCD distribution. HBCD diastereoisomer profiles showed that gamma-HBCD dominated in most of the sediment samples, followed by alpha- and beta-HBCD, which was consistent with those in the commercial HBCD mixtures. Further risk assessment reflected that the average inventories of HBCD were 18.3, 5.87, 3.92, 2.50, 1.77 ng/cm2 in sediments from Pearl River, Haihe River, Tarim River, Yellow River and Yangtze River, respectively.

  8. On the relationship between the winter Eurasian teleconnection pattern and the following summer precipitation over China

    NASA Astrophysics Data System (ADS)

    Zhao, Junhu; Yang, Liu; Gu, Bohui; Yang, Jie; Feng, Guolin

    2016-06-01

    The Eurasian teleconnection pattern (EU) is an important low-frequency pattern with well-known impacts on climate anomalies in Eurasia. The difference of low-level v-winds in several regions in the Eurasian mid-high latitudes is defined as the EU index (EUIV). In this study, the relationship between the winter EUIV and precipitation in the following summer over China is investigated. Results show that there is a significant positive (negative) correlation between the winter EUIV and the following summer precipitation over North China (the Yangtze River-Huaihe River basins). Meanwhile, an interdecadal variability exists in the interannual relationship, and the correlation has become significantly enhanced since the early 1980s. Thus, the proposed EUIV may have implications for the prediction of summer precipitation anomalies over China. In positive winter EUIV years, three cyclonic circulation anomalies are observed—over the Ural Mountains, the Okhotsk Sea, and the subtropical western North Pacific. That is, the Ural blocking and Okhotsk blocking are inactive, zonal circulation prevails in the mid-high latitudes, and the western Pacific subtropical high tends to be weaker and locates to the north of its normal position in the following summer. This leads to above-normal moisture penetrating into the northern part of East China, and significant positive (negative) precipitation anomalies over North China (the Yangtze River-Huaihe River basins), and vice versa. Further examination shows that the SST anomalies over the Northwest Pacific and subtropical central North Pacific may both contribute to the formation of EUIV-related circulation anomalies over the western North Pacific.

  9. Water resources: the prerequisite for ecological restoration of rivers in the Hai River Basin, northern China.

    PubMed

    Tang, Wenzhong; Mao, Zhanpo; Zhang, Hong; Shan, Baoqing; Zhao, Yu; Ding, Yuekui

    2015-01-01

    The competition for water resources between humans and river ecosystems is becoming ever more intense worldwide, especially in developing countries. In China, with rapid socioeconomic development, water resources to maintain river ecosystems are progressively decreasing, especially in the Hai River Basin (HRB), which has attracted much attention from the Chinese government. In the past 56 years, water resources have continuously decreased in the basin, such that there is 54.2 % less surface water now compared with then. Water shortages, mainly due to local anthropogenic activities, have emerged as the main limiting factor to river ecological restoration in the HRB. However, the South-to-North Water Diversion Project, the largest such project in the world, presents a good opportunity for ecological restoration of rivers in this basin. Water diverted from the Danjiangkou Reservoir will restore surface water resources in the HRB to levels of 30 years ago and will amount to more than 20 billion m(3). Our findings highlight the fact that water resources are crucial for river ecological restoration.

  10. Streamflow Simulations for Major River Basins in China

    NASA Astrophysics Data System (ADS)

    Su, F.; Xie, Z.; Liang, X.

    2002-12-01

    In this study, the land surface scheme (LSS) of VIC (Variable Infiltration Capacity) model is used to simulate streamflows of major river basins in China where the new surface runoff parameterization of VIC that represents both Horton and Dunne runoff generation mechanisms with the framework of considering subgrid spatial scale soil heterogeneity is applied. The entire area of China is represented by 2604 cells with a resolution of 60km­A60km for each cell. The VIC model is applied to each grid cell over each basin. A routing scheme is run offline which takes daily VIC surface and subsurface runoff as input to obtain model simulated streamflows at the outlets of study basins. Preparation of the forcing data, and soil and vegetation parameters needed by the VIC model for the entire area of China will be described, and some of the data issues will be addressed and discussed. The VIC streamflow simulations over a few river basins will be presented and compared with the observations.

  11. Water resource management in river oases along the Tarim River in North-West of China

    NASA Astrophysics Data System (ADS)

    Kliucininkaite, Lina; Disse, Markus

    2013-04-01

    Tarim River is one of the longest inland rivers in the world. It flows its water in the northern part of the Taklamakan desert in Xinjiang, North-west of China, which is a very hostile region due its climatic conditions and particularly due to low precipitation and very high evaporation rates. During the past five decades intensive exploitation of water resources, mainly by agricultural activities, has changed the temporal and spatial distribution of them and caused serious environmental problems in the Tarim River Basin. The support measures for oasis management along the Tarim River under climatic and societal changes became the overarching goal of this research. The temperature has risen by nearly 1° C over the past 50 years in the Tarim River Basin so more water was available in the mountainous areas of Xinjiang, leading to an increasing trend of the headstream discharges of the Tarim Basin. Aksu, Hotan and Yarkant Rivers are three tributaries of the Tarim River, as well as its main water suppliers. However, under the condition of water increase with the volume of 25×108 m3 in headstreams in recent 10 years, the water to the mainstream has increased less than 108 m3 (in Alar hydrological station), which is less than 3% of the increased water volume of runoff. Moreover, the region is one of the biggest cotton and other cash crops producers in China. In addition, expansion of urban and, in particular, of irrigation areas have caused higher water consumption at different parts of the river, leading to severe ecological effects on rural areas, especially in the lower reaches. Moreover, it also highly affects groundwater level and quality. The aim of this research is to support decision makers, planners and engineers to find right measures in the area for the further development of the region, as well as adaptation to changing climate. Different scenarios for water resource management, as well as water distribution and allocation in a more efficient and water

  12. Distribution of alkylphenols in the Pearl River Delta and adjacent northern South China Sea, China.

    PubMed

    Chen, Bing; Duan, Jing-Chun; Mai, Bi-xian; Luo, Xiao-Jun; Yang, Qing-Shu; Sheng, Guo-Ying; Fu, Jia-Mo

    2006-04-01

    The occurrence of alkylphenols (APs) was investigated in surface water and sediments from the Pearl River Delta and adjacent northern South China Sea. Most of the water samples contained detectable amounts of APs, ranging up to 0.628 microg l(-1) for nonylphenol (NP) and 0.068 microg l(-1) for octylphenol (OP). APs were found in all of the sediment samples with concentrations ranging from 59 to 7808 microg kg(-1) for NP and from 1 to 93 microg kg(-1) for OP. The Zhujiang River showed the highest concentrations of APs in both water and sediments. Significant decrease of APs concentrations going from the Zhujiang River to the Shiziyang River was observed. The Xijiang River contained concentrations of APs slightly higher in water but relatively lower in sediments than the Lingding Bay, which might be attributed to their different hydrodynamic and sedimentary characteristics. There was a decreasing trend of APs in water from the rivers to the estuary and further to the sea on the whole. In the Lingding Bay and its outer waters, concentrations of APs in sediments increased to a maximum and then decrease seaward, which was consistent with the distribution trend of the sediment organic carbon contents. Linear regression analyses showed the concentrations of APs were markedly correlated with the sediment organic carbon contents, indicating that the sediment organic carbon is an important factor controlling the levels of APs in sediments.

  13. Water Balance Change in Xia Ying River Basin, Qinghai Province, China

    NASA Astrophysics Data System (ADS)

    Cuo, L.; Zhou, B.; Li, J.

    2010-12-01

    Yellow River, Yangtze River and Lan Cang River are major river systems supporting billions of people in South East Asia and China. Source region of Yellow River, Yangtze River and Lan Cang River (Three Rivers) is located in Qinghai Province, China. Recently, Chinese government started a conservation project in the source region of the Three Rivers called “Convert Agricultural Field to Forest and Grassland”. Xia Ying River Basin is a sub-basin located in the source region of the Three River Basin. The upper Xia Ying River Basin has experienced dramatic land cover change since 2006. Before 2006, upper Xia Ying River Basin hill slope was agricultural field. Coniferous trees and bush vegetation were planted on the slope greater than 70 degree in the upper Xia Ying River Basin in 2006. The objective of the study is to investigate the water balance term change in the Xia Ying River Basin because of the conservation project. This study will use Landsat and MODIS imagery to classify and quantify land cover classes before and after land cover conversion. Water balance terms including runoff and evaportranspiration will be simulated using a land surface model to investigate water balance term change due to land cover change. The study serves as a pilot study for the investigation of hydrological change in the entire source region of the Three River Basin during the past 50 years.

  14. [Ecological function evaluation and related management strategies of river ecosystem in Taizi River basin, North China].

    PubMed

    Liu, Hong-Yan; Zhang, Yuan; Ma, Shu-Qin; Meng, Wei

    2013-10-01

    By the method of index evaluation at reach scale, this paper evaluated the ecological functions of aquatic biodiversity maintenance, habitat maintenance, water quality sustainment, and hydrological support of the river system in Taizi River basin of North China. The dominant ecological functions and the total ecological function were determined after sorting and summing. All the reaches in the basin were divided into four hierarchies of ecological functions. Overall, the total ecological function showed a spatially degrading trend from the mountainous region to the plain. Based on the evaluation results of the total function and dominant functions, six ecosystem management strategies were proposed. For the reaches with the functions of aquatic biodiversity- and habitat maintenance, the primary ecological management strategies included ecological conservation, ecological maintenance, and ecological restoration; for the reaches with the functions of water quality sustainment and hydrological support, the primary strategies of ecological management included limited development, development optimization, and exploitation.

  15. [Runoff process in forested basin of Hun River-Taizi River, Northeast China: a simulation study].

    PubMed

    Cai, Yan-Cong; Jin, Chang-Jie; Wang, An-Zhi; Guan, De-Xini; Wu, Jia-Bing; Yuan, Feng-Hui

    2013-10-01

    Based on the hydrological data from the Beikouqian and Nandianyu stations in the upstream of Hun River and Taizi River as well as the meteorological data from the Qingyuan, Xinbin, and Benxi County stations, Northeast China in 1998-2007, a distributed hydrological model (DHS-VM) was applied to simulate the hydrological process in Hun-Tai basin. The scientific applicability of the model was validated, and the reference values of the most sensitive model parameters were provided. The simulated monthly runoff Nash-Suttclife coefficient (E value) for the source region of Hun River in calibration period (1998-2002) and validation period (2003-2007) was 0.9675 and 0. 8957, respectively, which could better reappear the monthly runoff process in this source region. The simulated monthly and annual runoff E values for the upstream of Taizi River were greater than 0.6, indicating that this model had good applicability in Hun-Tai basin, and the calibrated parameter scheme had a good reliability. This paper established a solid framework for the hydrological study over ungauged basin, and constructed a reasonable parameter scheme.

  16. Sulfur fluxes and isotopic compositions of the major rivers in China

    NASA Astrophysics Data System (ADS)

    Liu, C.; Lang, Y.; Tian, L.; Ding, H.; Strauss, H.; Zhao, Z.; Li, S.; Li, X.; Hu, J.

    2012-12-01

    Sulfur is widely distributed in the environment by volcanism, volatile emissions, precipitation, acid mine drainage and anthropogenic activity. Since the industrial revolution, the atmospheric sulfur cycle has been dominated by anthropogenic sources. Combustion of sulfur-containing fossil fuels release large quantities of sulfur dioxide into Earth's atmosphere annually. The cycling of sulfur, among those of many elements, is seriously disturbed by human activities at the earth's surface. Therefore, it is important to obtain a better understanding of sources and cycling processes of sulfur in river basins. For this purpose, we have measured the sulfur isotope composition of sulfate and its concentration for Changjiang (Yangtze River), Huanghe (Yellow River), Liaohe (Liao River), and Songhuajiang (Songhua River) in China. The sulfate fluxes of the major rivers in southern China are significantly larger as compared with the rivers in northern China. Sulfur isotopic compositions (δ34S) of sulfate in the rivers do not show a variation trend from southern to northern China. The sulfate δ34S values are 4.3‰~9.8‰ for Changjiang, 5.0‰~10.0‰ for most of river waters of Huanghe, and 2.0‰~27.0‰ for Songhuajiang. For Zhujiang (Pearl River), three sulfate δ34S values are from 1.0‰~6.9‰. The coal produced in southern China is generally of lower δ34S values as compared with that in northern China. The distributions of the sulfate δ34S values of the river waters of are generally lower in southern China, showing the contribution of atmospheric deposition of sulfur into the river water. Three main sources, atmospheric deposition (mostly anthropogenic), dissolution of sulfate evaporate, oxidation of sulfide minerals and/or sulfur-containing organic matter in soil, have been recognized for the sulfate in the rivers. Relative contributions of the different sulfur sources into the sulfate of the rivers are different, suggesting that sulfur cycling in the different

  17. Integrative fuzzy hierarchical model for river health assessment: A case study of Yong River in Ningbo City, China

    NASA Astrophysics Data System (ADS)

    Zhao, Y. W.; Yang, Z. F.

    2009-04-01

    Due to the increasingly serious ecological degradation of river systems, the river health research has attracted more and more attention of the researchers and decision-makers. This paper aims to integrate the fuzzy assessment method with analytic hierarchy process to establish the integrative fuzzy hierarchical assessment model, thus combing qualitative analysis and quantitative assessment and overcoming the disadvantages of subjectivity of the previous evaluation methods. The results show that the proposed assessment method is able to reveal how the river system is disturbed by human activities. Finally, the integrative fuzzy hierarchical method is validated and applied to the case study of Yong River in Ningbo City, China.

  18. 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

  19. Impact of Yangtze river water transfer on the water quality of the Lixia river watershed, China.

    PubMed

    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.

  20. In vitro toxicity assessment of sediment samples from Huangpu River and Suzhou River, Shanghai, China.

    PubMed

    Lou, Shufang; Lei, Bingli; Feng, Chenglian; Xu, Jie; Peng, Wei; Wang, Yipei

    2016-08-01

    Sediments are the ultimate sink for many toxic organic contaminants released into aquatic environment. The present study evaluated the toxicity effect of 13 surface sediment samples from Huangpu River and Suzhou River, East China using two-hybrid yeast bioassays for estrogenic and thyroidal effects and H4IIE rat hepatoma cell bioassay for ethoxyresorufin O-deethylase (EROD) activity. Toxicity was expressed as 17β-estradiol equivalent (E2-EQ), 3,3',5-triiodothyronine equivalent (T3-EQ), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent (TEQ). At the same time, the causality between the observed EROD activity and concentrations of polycyclic aromatic hydrocarbons (PAHs) was examined. The results showed that the total estrogenic effects in sediments ranged from 0.06 to 1.21 μg E2-EQ kg(-1) dry weight (dw), the thyroidal effects ranged from 4.68 to 69.9 μg T3-EQ kg(-1) dw, and significantly positive correlations were found between lgT3-EQs and lgE2-EQs. The AhR agonist effects varied from 26.5 to 148.3 ng TEQ kg(-1) dw. Chemical analysis-derived TEQs contributed by PAHs ranged from 13.8 to 66.0 ng kg(-1) dw accounting for 27.2-109.9 % with mean of 48.9 % of TEQbio, indicating that PAHs made important contributions to the EROD effects of sediment extracts from the two rivers. The present study would provide meaningful information for further analysis and risk evaluation for organic pollutants in Huangpu River and Suzhou River.

  1. Development and preliminary application of a method to assess river ecological status in the Hai River Basin, north China.

    PubMed

    Shan, Baoqing; Ding, Yuekui; Zhao, Yu

    2016-01-01

    The river ecosystem in the Hai River Basin (HRB), an important economic region in China, is seriously degraded. With the aim of river restoration in the HRB, we developed a method to assess the river's ecological status and conducted a preliminary application of the method. The established method was a predictive model, which used macroinvertebrates as indicator organisms. The river's ecological status was determined by calculating the ratio of observed to expected values (O/E). The method included ecoregionalization according to natural factors, and the selection of reference sites based on combinations of habitat quality and macroinvertebrate community. Macroinvertebrate taxa included Insecta, Crustacea, Gastropoda, and Oligochaeta, with 39 families and 95 genera identified in the HRB. The HRB communities were dominated by pollution tolerant taxa, such as Lymnaeidae, Chironomus, Limnodrilus, Glyptotendipes, and Tubifex. The average Shannon-Wiener index was 1.40±0.5, indicating a low biodiversity. In the river length of 3.31×10(4) km, 55% of the sites were designated poor, with a bad ecological status. Among nine secondary river systems, Luan and Zi-ya had the best and worst river conditions, respectively. Only 17 reference site groups were selected for river management in the 41 ecoregions examined. This study lays the foundation for river restoration and related research in the HRB, and we anticipate further developments of this novel method. PMID:26899653

  2. Understanding the dynamics of water availability and use in China

    SciTech Connect

    Thomas, R.P.; Conrad, S.H.; Jeppesen, D.M.; Engi, E.

    1997-07-01

    This report presents the preliminary results of an analysis of China`s water resources, part of an effort undertaken by the National Intelligence Council Medea scientists to improve the understanding of future food production and consumption in the People`s Republic of China. A dynamic water model was developed to simulate the hydrological budgetary processes in five river drainage basins located in northeastern, central, and southern China: the Chang Jiang (Yangtse River), Huanghe (Yellow River), Haihe, Huaihe, and Liaohe. The model was designed to assess the effects of changes in urban, industrial, and agricultural water use requirements on the availability of water in each basin and to develop estimates of the water surpluses and/or deficits in China through the year 2025. The model imposes a sustainable yield constraint, that is, groundwater extraction is not allowed to exceed the sustainable yield; if the available water does not meet the total water use requirements, a deficit results. An agronomic model was also developed to generate projections of the water required to service China`s agricultural sector and compare China`s projected grain production with projected grain consumption requirements to estimate any grain surplus and/or deficit. In future refinements, the agronomic model will interface directly with the water model to provide for the exchange of information on projected water use requirements and available water. The preliminary results indicate that the Chang Jiang basin will have a substantial surplus of water through 2025 and that the Haihe basin is in an ongoing situation. The agricultural water use requirements based on grain production indicate that an agricultural water deficit in the Haihe basin begins before the onset of the modeling period (1980) and steadily worsens through 2025. This assumption is confirmed by reports that groundwater mining is already under way in the most intensely cultivated and populated areas of northern China.

  3. 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.

  4. Seed banks and their implications of rivers with different trophic levels in Chaohu Lake Basin, China.

    PubMed

    Cui, Naxin; Wu, Juan; Zhong, Fei; Yang, Lihua; Xiang, Dongfang; Cheng, Shuiping; Zhou, Qi

    2015-02-01

    The seed banks of three rivers, with different trophic levels in Chaohu Lake Basin, China, were investigated to explore the dynamics of seed bank under the pressure of eutrophication. A total of 60 species from 25 family 43 genera were identified from the seed banks of the three rivers. In the eutrophic Paihe River, the species richness and mean seed density were the highest, followed by the oligotrophic Hangbuhe River and the hypereutrophic Nanfeihe River. Various compositions of three functional group assemblage of hydro-ecotypes were found in different rivers. The dominant and endemic species were aquatic, wetland, and terrestrial species in Hangbuhe River, Paihe River, and Nanfeihe River, respectively. The shift trend of seed bank in three rivers probably presented past vegetation dynamics under the trophic process in the rivers of Chaohu Lake Basin. Seed bank in the river bed might be quickly assessed by its trophic level. Additionally, it might imply that the seed bank with more aquatic species in the oligotrophic river would be a potential seed resource for vegetation restoration of severely degraded river ecosystems.

  5. Changes in precipitation and temperature in Xiangjiang River Basin, China

    NASA Astrophysics Data System (ADS)

    Ma, Chong; Pan, Suli; Wang, Guoqing; Liao, Yufang; Xu, Yue-Ping

    2016-02-01

    Global warming brings a huge challenge to society and human being. Understanding historic and future potential climate change will be beneficial to regional crop, forest, and water management. This study aims to analyze the precipitation and temperature changes in the historic period and future period 2021-2050 in the Xiangjiang River Basin, China. The Mann-Kendall rank test for trend and change point analysis was used to analyze the changes in trend and magnitude based on historic precipitation and temperature time series. Four global climate models (GCMs) and a statistical downscaling approach, LARS-WG, were used to estimate future precipitation and temperature under RCP4.5. The results show that annual precipitation in the basin is increasing, although not significant, and will probably continue to increase in the future on the basis of ensemble projections of four GCMs. Temperature is increasing in a significant way and all GCMs projected continuous temperature increase in the future. There will be more extreme events in the future, including both extreme precipitation and temperature.

  6. Precipitation variability assessment of northeast China: Songhua River basin

    NASA Astrophysics Data System (ADS)

    Khan, Muhammad Imran; Liu, Dong; Fu, Qiang; Azmat, Muhammad; Luo, Mingjie; Hu, Yuxiang; Zhang, Yongjia; Abrar, Faiz M.

    2016-07-01

    Variability in precipitation is critical for the management of water resources. In this study, the research entropy base concept was applied to investigate spatial and temporal variability of the precipitation during 1964-2013 in the Songhua River basin of Heilongjiang Province in China. Sample entropy was applied on precipitation data on a monthly, seasonally, annually, decade scale and the number of rainy days for each selected station. Intensity entropy and apportionment entropy were used to calculate the variability over individual year and decade, respectively. Subsequently, Spearman's Rho and Mann-Kendall tests were applied to observe for trends in the precipitation time series. The statistics of sample disorder index showed that the precipitation during February (mean 1.09, max. 1.26 and min. 0.80), April (mean 1.12, max. 1.29 and min. 0.99) and July (mean 1.10, max. 1.20 and min. 0.98) contributed significantly higher than those of other months. Overall, the contribution of the winter season was considerably high with a standard deviation of 0.10. The precipitation variability on decade basis was observed to increase from decade 1964-1973 and 1994-2003 with a mean value of decadal apportionment disorder index 0.023 and 0.053, respectively. In addition, the Mann-Kendall test value (1.90) showed a significant positive trend only at the Shangzhi station.

  7. 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.

  8. Source of atmospheric moisture and precipitation over China's major river basins

    NASA Astrophysics Data System (ADS)

    Zhao, Tongtiegang; Zhao, Jianshi; Hu, Hongchang; Ni, Guangheng

    2016-03-01

    Oceanic evaporation via the East Asian Monsoon (EAM) has been regarded as the major source of precipitation over China, but a recent study estimated that terrestrial evaporation might contribute up to 80% of the precipitation in the country. To explain the contradiction, this study presents a comprehensive analysis of the contribution of oceanic and terrestrial evaporation to atmospheric moisture and precipitation in China's major river basins. The results show that from 1980 to 2010, the mean annual atmospheric moisture (precipitable water) over China was 13.7 mm, 39% of which originates from oceanic evaporation and 61% from terrestrial evaporation. The mean annual precipitation was 737 mm, 43% of which originates from oceanic evaporation and 57% from terrestrial evaporation. Oceanic evaporation makes a greater contribution to atmospheric moisture and precipitation in the East Asian Monsoon Region in South and East China than terrestrial evaporation does. Particularly, for the Pearl River and southeastern rivers, oceanic evaporation contributes approximately 65% of annual precipitation and more than 70% of summer precipitation. Meanwhile, terrestrial evaporation contributes more precipitation in northwest China due to the westerly wind. For the northwestern rivers, terrestrial evaporation from the Eurasian continents contributes more than 70% of precipitation. There is a linear relation between mean annual precipitation and the contribution of oceanic evaporation to precipitation, with a correlation coefficient of 0.92, among the ten major river basins in China.

  9. [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.

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

    SciTech Connect

    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, 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

  11. Simulation of the radiative effect of black carbon aerosols and the regional climate responses over China

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Jiang, Weimei; Fu, Congbin; Su, Bingkai; Liu, Hongnian; Tang, Jianping

    2004-08-01

    As part of the development work of the Chinese new regional climate model (RIEMS), the radiative process of black carbon (BC) aerosols has been introduced into the original radiative procedures of RIEMS, and the transport model of BC aerosols has also been established and combined with the RIEMS model. Using the new model system, the distribution of black carbon aerosols and their radiative effect over the China region are investigated. The influences of BC aerosole on the atmospheric radiative transfer and on the air temperature, land surface temperature, and total rainfall are analyzed. It is found that BC aerosols induce a positive radiative forcing at the top of the atmosphere (TOA), which is dominated by shortwave radiative forcing. The maximum radiative forcing occurs in North China in July and in South China in April. At the same time, negative radiative forcing is observed on the surface. Based on the radiative forcing comparison between clear sky and cloudy sky, it is found that cloud can enforce the TOA positive radiative forcing and decrease the negative surface radiative forcing. The responses of the climate system in July to the radiative forcing due to BC aerosols are the decrease in the air temperature in the middle and lower reaches of the Changjiang River and Huaihe area and most areas of South China, and the weak increase or decrease in air temperature over North China. The total rainfall in the middle and lower reaches of the Changjiang River area is increased, but it decreased in North China in July.

  12. Sustainable management of river oases along the Tarim River in North-Western China under conditions of climate change

    NASA Astrophysics Data System (ADS)

    Rumbaur, C.; Thevs, N.; Disse, M.; Ahlheim, M.; Brieden, A.; Cyffka, B.; Doluschitz, R.; Duethmann, D.; Feike, T.; Frör, O.; Gärtner, P.; Halik, Ü.; Hill, J.; Hinnenthal, M.; Keilholz, P.; Kleinschmit, B.; Krysanova, V.; Kuba, M.; Mader, S.; Menz, C.; Othmanli, H.; Pelz, S.; Schroeder, M.; Siew, T. F.; Stender, V.; Stahr, K.; Thomas, F. M.; Welp, M.; Wortmann, M.; Zhao, X.; Chen, X.; Jiang, T.; Zhao, C.; Zhang, X.; Luo, J.; Yimit, H.; Yu, R.

    2014-10-01

    The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of China and one of the largest in whole Central Asia. Due to the extremely arid climate with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim River solely depends on river water. This applies for anthropogenic activities (e.g. agriculture) as well as for the natural ecosystems so that both compete for water. The on-going increase of water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes formed the consortium SuMaRiO (www.sumario.de), which aims at gaining a holistic picture of the availability of water resources in the Tarim River Basin and the impacts on anthropogenic activities and natural ecosystems caused by the water distribution within the Tarim River Basin. The discharge of the Aksu River, which is the major tributary to the Tarim, has been increasing over the past 6 decades due to enhanced glacier melt. Alone from 1989 to 2011, the area under agriculture more than doubled. Thereby, cotton became the major crop and there was a shift from small-scale farming to large-scale intensive farming. The major natural ecosystems along the Aksu and Tarim River are riparian ecosystems: Riparian (Tugai) forests, shrub vegetation, reed beds, and other grassland. Within the SuMaRiO Cluster the focus was laid on the Tugai forests, with Populus euphratica as dominant tree, because the most productive and species-rich natural ecosystems can be found among those forests. On sites with groundwater distance of less than 7.5 m the annual increments correlated with river runoffs of the previous year. But, the further downstream along the Tarim River, the more the natural river dynamics ceased, which impacts on the recruitment of

  13. Contamination profiles of perfluoroalkyl substances in five typical rivers of the Pearl River Delta region, South China.

    PubMed

    Pan, Chang-Gui; Ying, Guang-Guo; Liu, You-Sheng; Zhang, Qian-Qian; Chen, Zhi-Feng; Peng, Feng-Jiao; Huang, Guo-Yong

    2014-11-01

    A survey on contamination profiles of eighteen perfluoroalkyl substances (PFASs) was performed via high performance liquid chromatography-tandem mass spectrometry for surface water and sediments from five typical rivers of the Pearl River Delta region, South China in summer and winter in 2012. The total concentrations of the PFASs in the water phase of the five rivers ranged from 0.14 to 346.72 ng L(-1). The PFAS concentrations in the water phase were correlated positively to some selected water quality parameters such as chemical oxygen demand (COD) (0.7913) and conductivity (0.5642). The monitoring results for the water samples showed significant seasonal variations, while those for the sediment samples showed no obvious seasonal variations. Among the selected 18 PFASs, perfluorooctane sulfonic acid (PFOS) was the dominant PFAS compound both in water and sediment for two seasons with its maximum concentration of 320.5 ng L(-1) in water and 11.4 ng g(-1) dry weight (dw) in sediment, followed by perfluorooctanoic acid (PFOA) with its maximum concentration of 26.48 ng L(-1) in water and 0.99 ng g(-1) dw in sediment. PFOS and PFOA were found at relatively higher concentrations in the Shima River and Danshui River than in the other three rivers (Xizhijiang River, Dongjiang River and Shahe River). The principal component analysis for the PFASs concentrations in water and sediment separated the sampling sites into two groups: rural and agricultural area, and urban and industrial area, suggesting the PFASs in the riverine environment were mainly originated from industrial and urban activities in the region.

  14. Chiral profiling of azole antifungals in municipal wastewater and recipient rivers of the Pearl River Delta, China.

    PubMed

    Huang, Qiuxin; Wang, Zhifang; Wang, Chunwei; Peng, Xianzhi

    2013-12-01

    Enantiomeric compositions and fractions (EFs) of three chiral imidazole (econazole, ketoconazole, and miconazole) and one chiral triazole (tebuconazole) antifungals were investigated in wastewater, river water, and bed sediment of the Pearl River Delta, South China. The imidazole pharmaceuticals in the untreated wastewater were racemic to weakly nonracemic (EFs of 0.450-0.530) and showed weak enantioselectivity during treatment in the sewage treatment plant. The EFs of the dissolved azole antifungals were usually different from those of the sorbed azoles in the suspended particulate matter, suggesting different behaviors for the enantiomers of the chiral azole antifungals in the dissolved and particulate phases of the wastewater. The azole antifungals were widely present in the rivers. The bed sediment was a sink for the imidazole antifungals. The imidazoles were prevalently racemic, whereas tebuconazole was widely nonracemic in the rivers. Seasonal effects were observed on distribution and chirality of the azole antifungals. Concentrations of the azole antifungals in the river water were relatively higher in winter than in spring and summer while the EF of miconazole in the river water was higher in summer. The mechanism of enantiomeric behavior of the chiral azole antifungals in the environment warrants further research.

  15. Changes in runoff and eco-flow in the Dongjiang River of the Pearl River Basin, China

    NASA Astrophysics Data System (ADS)

    Lin, Kairong; Lian, Yanqing; Chen, Xiaohong; Lu, Fan

    2014-12-01

    The Dongjiang River, one of the tributaries of the Pearl River, serves as the critical water source for Guangdong Province and the District of Hong Kong in China. In this study, the change trend and change points of flow at three main gaging stations in the Dongjiang River were analyzed using the nonparametric Mann-Kendall test and Pettitt-Mann-Whitney change-point statistics. Flow regime changes in the Dongjiang River were quantified by using both the Indicators of Hydrologic Alteration (IHA) parameters and eco-statistics, such as ecosurplus and ecodeficit. It was found that the change trend for annual median flow in the Dongjiang River increased over the past 60 years, with the major change occurring sometime between 1970 and 1974. IHA analyses showed that the magnitude of monthly flow decreased during the flood period, but increased greatly during the dry period. The median date of the one-day minimum flow moved ahead, and the duration of low pulse for the Dongjiang River was reduced significantly because of reservoir construction and operations. The IHA-based Dundee Hydrological Regime Alteration Method analysis indicated that all three stations have experienced a moderate risk of impact since 1974. The eco-statistical analyses showed that the majority of the flows appeared to be ecosurplus at all three locations after 1974, while flows with less than 30%, or higher exceedance probability, had ecodeficit in the summer flood period due to heavy reservoir operations.

  16. Managing water resources for sustainable development: the case of integrated river basin management in China.

    PubMed

    Song, X; Ravesteijn, W; Frostell, B; Wennersten, R

    2010-01-01

    The emerging water crisis in China shows that the current institutional frameworks and policies with regard to water resources management are incapable of achieving an effective and satisfactory situation that includes Integrated River Basin Management (IRBM). This paper analyses this framework and related policies, examines their deficiencies in relation to all water stress problems and explores alternatives focusing on river basins. Water resources management reforms in modern China are reviewed and the main problems involved in transforming the current river management system into an IRBM-based system are analysed. The Huai River basin is used as an example of current river basin management, with quantitative data serving to show the scale and scope of the problems in the country as a whole. The institutional reforms required are discussed and a conceptual institutional framework is proposed to facilitate the implementation of IRBM in China. In particular, the roles, power and responsibilities of River Basin Commissions (RBCs) should be legally strengthened; the functions of supervising, decision-making and execution should be separated; and cross-sectoral legislation, institutional coordination and public participation at all levels should be promoted.

  17. Residential Preferences for River Network Improvement: An Exploration of Choice Experiments in Zhujiajiao, Shanghai, China

    NASA Astrophysics Data System (ADS)

    Che, Yue; Li, Wen; Shang, Zhaoyi; Liu, Chen; Yang, Kai

    2014-09-01

    River networks have both ecological and social benefits for urban development. However, river networks have suffered extensive destruction as a result of urbanization and industrialization, especially in China. River restoration is a growth business but suffers poor efficiency due to a lack of social understanding. Assessing the benefits of river system restoration and recognizing public preferences are critical for effective river ecosystem restoration and sustainable river management. This study used a choice experiment with a multinomial logit model and a random parameter logit model to assess respondents' cognitive preferences regarding attributes of river networks, and their possible sources of heterogeneity. Results showed that riverfront condition was the attribute most preferred by respondents, while stream morphology was the least preferred. Results also illustrated that the current status of each of three river network attributes was not desirable, and respondents would prefer a river network with a "branch pattern," that is "limpid with no odor," and "accessible with vegetation." Estimated willingness to pay was mainly affected by household monthly income, residential location, and whether respondents had household members engaged in a water protection career. The assessment results can provide guidance and a reference for managers, sponsors, and researchers.

  18. Past climate and land cover change impacts on streamflow in upper Yellow River Basin, China

    NASA Astrophysics Data System (ADS)

    Cuo, L.

    2011-12-01

    Upper Yellow River Basin is located in the northern Tibetan Plateau. More than half of the annual total yield of the entire Yellow River is contributed from the Upper Yellow River Basin. Like the other part of the world, upper Yellow River Basin has been experiencing climate change. Also, sponsored by China Central Government, local Provincial government launched "Returning Farm Land and Grazing Land to Grasses and Forests" in 2000 and "Three Rivers' Source Region Environmental Protection Project" in 2005 to conserve ecosystem in the source region of the Yellow River. Understanding climate and land cover change impacts on the streamflow in the upper Yellow River Basin is essential for local and downstream ecosystems. This study utilized a large scale hydrology model - Variable Infiltration Capacity model to investigate both climate and land cover change impacts on the streamflow in the upper Yellow River Basin. Past 50-year of climate data, and 1994 and 2004 land cover data obtained from NOAA AVHRR and MODIS satellites were used in the study. 1994 and 2004 were the years before and after the execution of environmental protection programs. The investigation revealed that warmer climate has resulted in lower annual total streamflow, higher spring peak but lower summer flow. After launching the ecosystem conservation programs, streamflow has decreased. In the source region of the Yellow River, climate change impact dominates over land cover change impact.

  19. 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...

  20. Invasions and impacts of alligatorweed in the upper Xiaoqing River basin of northern China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alligatorweed (Alternanthera philoxeroides (Mart.) Griseb), is a problematic and difficult to manage invasive weed. The recent invasion in the upper Xiaoqing River, northern China extends its range northwards through almost five degrees latitude and 500 km from the northern limit and main invasion a...

  1. 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.

  2. 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.

  3. Emission of volatile organic sulfur compounds from a heavily polluted river in Guangzhou, South China.

    PubMed

    Sheng, Yanqing; Chen, Fanzhong; Yu, Ying; Wang, Xinming; Sheng, Guoying; Fu, Jiamo; Zeng, Eddy Y

    2008-08-01

    Emissions of five volatile organic sulfur compounds (VOSCs), including methanethiol, carbonyl sulfide, dimethyl sulfide, carbon disulfide, and dimethyl disulfide, from a heavily polluted river, Shijing River in Guangzhou of South China, was studied. The results showed that the amounts of all VOSCs emitted from the river increased from downstream to upstream along the river with increasing magnitude of water pollution. The emission of carbonyl sulfide was the highest among the target analytes, ranging from 23.8 microg m(-2) h(-1) to 42.6 microg m(-2) h(-1) at the water surface of Shijin River. The concentration levels of VOSCs on the riverbank were lower than those at the water surface either in Shijing River or in Liuxi River. However, the contribution of dimethyl disulfide to the total VOSCs on the riverbank was higher than that at the water surface in most sampling sites, indicating that there might be a point source of dimethyl disulfide on the riverbank besides diffusion from water surface. The 24-h semi-continuous monitoring data revealed that the emissions of VOSCs at the water surface peaked at 9:00 and 21:00, which was consistent with the water quality variability in Shijin River caused by daily tidal variation.

  4. Major ion chemistry and dissolved inorganic carbon cycling in a human-disturbed mountainous river (the Luodingjiang River) of the Zhujiang (Pearl River), China.

    PubMed

    Zhang, Shurong; Lu, X X; Sun, Huiguo; Han, Jingtai; Higgitt, David Laurence

    2009-04-01

    Major ion chemistry and dissolved inorganic carbon system (DIC, mainly HCO3(-) and gaseous CO2) in the Luodingjiang River, a mountainous tributary of the Zhujiang (Pearl River), China, were examined based on a seasonal and spatial sampling scheme in 2005. The diverse distribution of lithology and anthropogenic impacts in the river basin provided the basic idea to assess the effects of lithology vs. human activities on water chemistry and carbon biogeochemistry in river systems. Major ions showed great spatial variations, with higher concentrations of total dissolved solids (TDS) and DIC in the regions with carbonate rocks and clastic sedimentary rocks, while lower in the regions with metamorphic sandstones and schists as well as granites. pCO2 at all sampling sites was oversaturated in June, ranging with a factor from 1.6 to 18.8 of the atmospheric concentration, reflecting the enhanced contribution from baseflow and interflow influx as well as in situ oxidation of organic matter. However, in April and December, undersaturated pCO2 was found in some shallow, clean rivers in the upstream regions. delta13C of DIC has a narrow range from -9.07 to -13.59 per thousand, which was more depleted in the regions with metamorphic rocks and granites than in the carbonate regions. Seasonally, it was slightly more depleted in the dry season (December) than in the wet season (June). The results suggested that lithological variability had a dominant control on spatial variations of water chemistry and carbon geochemistry in river systems. Besides, anthropogenic activities, such as agricultural and urban activities and in-stream damming, as well as river physical properties, such as water depth and transparency, also indicated their impacts. The seasonal variations likely reflected the changes of hydrological regime, as well as metabolic processes in the river.

  5. Major ion chemistry and dissolved inorganic carbon cycling in a human-disturbed mountainous river (the Luodingjiang River) of the Zhujiang (Pearl River), China.

    PubMed

    Zhang, Shurong; Lu, X X; Sun, Huiguo; Han, Jingtai; Higgitt, David Laurence

    2009-04-01

    Major ion chemistry and dissolved inorganic carbon system (DIC, mainly HCO3(-) and gaseous CO2) in the Luodingjiang River, a mountainous tributary of the Zhujiang (Pearl River), China, were examined based on a seasonal and spatial sampling scheme in 2005. The diverse distribution of lithology and anthropogenic impacts in the river basin provided the basic idea to assess the effects of lithology vs. human activities on water chemistry and carbon biogeochemistry in river systems. Major ions showed great spatial variations, with higher concentrations of total dissolved solids (TDS) and DIC in the regions with carbonate rocks and clastic sedimentary rocks, while lower in the regions with metamorphic sandstones and schists as well as granites. pCO2 at all sampling sites was oversaturated in June, ranging with a factor from 1.6 to 18.8 of the atmospheric concentration, reflecting the enhanced contribution from baseflow and interflow influx as well as in situ oxidation of organic matter. However, in April and December, undersaturated pCO2 was found in some shallow, clean rivers in the upstream regions. delta13C of DIC has a narrow range from -9.07 to -13.59 per thousand, which was more depleted in the regions with metamorphic rocks and granites than in the carbonate regions. Seasonally, it was slightly more depleted in the dry season (December) than in the wet season (June). The results suggested that lithological variability had a dominant control on spatial variations of water chemistry and carbon geochemistry in river systems. Besides, anthropogenic activities, such as agricultural and urban activities and in-stream damming, as well as river physical properties, such as water depth and transparency, also indicated their impacts. The seasonal variations likely reflected the changes of hydrological regime, as well as metabolic processes in the river. PMID:19185905

  6. Estimation of environmental flow requirements for the river ecosystem in the Haihe River Basin, China.

    PubMed

    Yang, Tao; Liu, Jingling; Chen, Qiuying; Zhang, Jing; Yang, Yi

    2013-01-01

    The temporal and spatial environmental flow requirements (EFRs) for the river ecosystem of the Haihe River Basin were analyzed based mainly on the eco-functional regionalization of available water resources. The annual EFRs for the river ecosystem of the Haihe River Basin were 47.71 × 10(8) m(3), which accounted for 18% of the average annual flow (263.9 × 10(8) m(3)). The EFRs for river reaches, wetlands, and estuaries were 22.67, 15.32 and 9.72 × 10(8) m(3), respectively. Moreover, the EFRs for the river ecosystem during the wet (June to October), normal (April, May, November), and dry (December to March) periods were 29.99, 9.51 and 8.21 × 10(8) m(3), respectively. Thus, toward a more integrated water resource allocation in the Haihe River Basin, the primary effort should focus on meeting the EFRs for river systems located in protected areas during the dry period.

  7. Spatiotemporal variations of soil moisture in the Tarim River basin, China

    NASA Astrophysics Data System (ADS)

    Su, Buda; Wang, Anqian; Wang, Guojie; Wang, Yanjun; Jiang, Tong

    2016-06-01

    Based on in situ soil moisture and river runoff records in the Tarim River basin, usability of the long term Essential Climate Variable (ECV) soil moisture dataset is validated in the arid climatic region of China. The spatio-temporal variation of soil moisture and its possible influencing factors in the 1988-2013 is also preliminary analyzed in the current paper. Results reveal that the ECV soil moisture can capture the large scale dynamics of regional water cycle quite satisfactorily, showing good agreement with in situ observations in their seasonal and interannual variability. In the period of 1988-2013, the ECV soil moisture shows obvious increasing trends in the northwest and the southwest parts of the Tarim River basin, particularly in spring (March-May) and autumn (September-November). Statistical analysis further suggests that the variations of soil moisture in the Tarim River basin are more controlled by precipitation, and temperature is less effective in controlling of soil moisture variations.

  8. 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.

  9. 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.

  10. 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.

  11. Occurrence of phthalate esters in sediments in Qiantang River, China and inference with urbanization and river flow regime.

    PubMed

    Sun, Jianqiang; Huang, Jing; Zhang, Anping; Liu, Weiping; Cheng, Wenwei

    2013-03-15

    Phthalate esters (PAEs), a group of emerging organic contaminants, have become a serious issue arousing much attention for their ubiquitous presence and hazardous impact on the environment. This study provides the first data on distribution of PAEs in the sediments in the Qiantang River, Zhejiang Province, China, and the inference with urbanization and river flow regime. PAEs were detected in all 23 sediment samples analyzed, and the total concentrations of their 16 congeners in sediments ranged from 0.59 to 6.74μg/g dry weight (dw), with the geometric mean value of 2.03μg/g dw. Of the 16 PAE congeners, di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP) were present in all sediment samples. The PAEs concentrations in urban regions were higher than those in rural regions because of higher discharge of PAEs from plastic materials in urbanized areas. Concentrations of PAEs were positively correlated with sediment organic matter (fOM) and negatively correlated with logistic value of annual average flow volume at sample sites. River flow regime modified by man-made dams significantly affected the distribution of PAEs. Analysis of congener composition of PAEs indicated that the DEHP was predominant congener in the Qiantang River. The normalized concentration of DEHP exceeded recommended environmental risk limit (ERL).

  12. Water risk assessment for river basins in China based on WWF water risk assessment tools

    NASA Astrophysics Data System (ADS)

    Wei, N.; Qiu, Y.; Gan, H.; Niu, C.; Liu, J.; Gan, Y.; Zhou, N.

    2014-09-01

    Water resource problems, one of the most important environmental and socio-economic issues, have been a common concern worldwide in recent years. Water resource risks are attracting more and more attention from the international community and national governments. Given the current situations of water resources and the water environment, and the characteristics of water resources management and information statistics of China, this paper establishes an index system for water risk assessment in river basins of China based on the index system of water risk assessment proposed by the World Wide Fund For Nature (WWF) and German Investment and Development Co., Ltd (DEG). The new system is more suitable for Chinese national conditions and endorses the international assessment index. A variety of factors are considered to determine the critical values of classification for each index, and the indexes are graded by means of 5-grade and 5-score scales; the weights and calculation methods of some indexes are adjusted, with the remaining indexes adopting the method of WWF. The Weighted Comprehensive Index Summation Process is adopted to calculate the integrated assessment score of the river basin. The method is applied to the Haihe River basin in China. The assessment shows that the method can accurately reflect the water risk level of different river basins. Finally, the paper discusses the continuing problems in water risk assessment and points out the research required to provide a reference for further study in this field.

  13. 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 He Translated 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.

  14. Spatial distribution of perfluoroalkyl substances in surface sediments of five major rivers in China.

    PubMed

    Pan, Chang-Gui; Ying, Guang-Guo; Zhao, Jian-Liang; Liu, You-Sheng; Liu, Shuang-Shuang; Du, Jun; Kookana, Rai S

    2015-04-01

    Perfluoroalkyl substances (PFASs) have received great attention from the public and scientific community due to their potential adverse impacts on the ecosystem and human health. We investigated the occurrence and distribution of 16 PFASs from 2 classes of PFASs-perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids-in the archived surface sediments of five major rivers (Yellow River, Hai River, Liao River, Zhujiang River, and Dongjiang River) in northern and southern China. The study was also performed during the wet and dry seasons. Perfluorooctanoic acid and perfluorooctane sulfonic acid were the most frequently detected (detection frequency = 100 and 63 %, respectively) in the sediments of the five rivers; the concentrations ranged from 0.08 to 0.99 ng/g dry weight (dw) and were lower than the limit of detection (rivers in China.

  15. 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. PMID:27521638

  16. 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.

  17. Factors Contributing to Hypoxia in the Minjiang River Estuary, Southeast China.

    PubMed

    Zhang, Peng; Pang, Yong; Pan, Hongche; Shi, Chengchun; Huang, Yawen; Wang, Jianjian

    2015-08-11

    Dissolved oxygen (DO) is not only a fundamental parameter of coastal water quality, but also an indication of organics decomposed in water and their degree of eutrophication. There has been a concern about the deterioration of dissolved oxygen conditions in the Minjiang River Estuary, the longest river in Fujian Province, Southeast China. In this study, the syntheses effects on DO was analyzed by using a four year time series of DO concentration and ancillary parameters (river discharge, water level, and temperature) from the Fuzhou Research Academy of Environmental Sciences, at three automated stations along the Minjiang River Estuary. Hypoxia occurred exclusively in the fluvial sections of the estuary during the high temperature and low river discharge period and was remarkably more serious in the river reach near the large urban area of Fuzhou. Enhancement of respiration by temperature and discharge of domestic sewage and industrial wastewater, versus regeneration of waters and dilution of pollutant concentration with increased river discharge, which regarded as the dominant antagonist processes that controlled the appearance of seasonal hypoxia. During the high temperature and the drought period, minimal mainstream flow above 700 m(3)Ÿs(-1), reduction of pollutants and forbidding sediment dredging in the South Channel should be guaranteed for strong supports on water quality management and drinking water source protection.

  18. 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.

  19. Factors Contributing to Hypoxia in the Minjiang River Estuary, Southeast China

    PubMed Central

    Zhang, Peng; Pang, Yong; Pan, Hongche; Shi, Chengchun; Huang, Yawen; Wang, Jianjian

    2015-01-01

    Dissolved oxygen (DO) is not only a fundamental parameter of coastal water quality, but also an indication of organics decomposed in water and their degree of eutrophication. There has been a concern about the deterioration of dissolved oxygen conditions in the Minjiang River Estuary, the longest river in Fujian Province, Southeast China. In this study, the syntheses effects on DO was analyzed by using a four year time series of DO concentration and ancillary parameters (river discharge, water level, and temperature) from the Fuzhou Research Academy of Environmental Sciences, at three automated stations along the Minjiang River Estuary. Hypoxia occurred exclusively in the fluvial sections of the estuary during the high temperature and low river discharge period and was remarkably more serious in the river reach near the large urban area of Fuzhou. Enhancement of respiration by temperature and discharge of domestic sewage and industrial wastewater, versus regeneration of waters and dilution of pollutant concentration with increased river discharge, which regarded as the dominant antagonist processes that controlled the appearance of seasonal hypoxia. During the high temperature and the drought period, minimal mainstream flow above 700 m3·s−1, reduction of pollutants and forbidding sediment dredging in the South Channel should be guaranteed for strong supports on water quality management and drinking water source protection. PMID:26270670

  20. 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.

  1. 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

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

    PubMed

    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

  3. Polycyclic aromatic hydrocarbons in water, sediment and soil of the Songhua River Basin, China.

    PubMed

    Ma, Wan-Li; Liu, Li-Yan; Qi, Hong; Zhang, Zi-Feng; Song, Wei-Wei; Shen, Ji-Min; Chen, Zhong-Lin; Ren, Nan-Qi; Grabuski, Josey; Li, Yi-Fan

    2013-10-01

    The Songhua River is the third largest river in China and the primary source of drinking and irrigation water for northeastern China. The distribution of 16 priority polycyclic aromatic hydrocarbons (PAHs) in water [dissolved water (DW) and suspended particulate matter (SPM)], sediment, and soil in the river basin was investigated, and the associated risk of cancer from these PAHs was also assessed. The total concentration of PAHs ranged from 13.9 to 161 ng L(-1) in DW, 9.21 to 83.1 ng L(-1) in SPM, 20.5 to 632 ng g(-1) dw (dry weight) in sediment, and from 30.1 to 870 ng g(-1) dw in soil. The compositional pattern of PAHs indicated that three-ring PAHs were predominant in DW and SPM samples, while four-ring PAHs dominated in sediment and soil samples. The spatial distribution of PAHs revealed some site-specific sources along the river, with principal component analysis indicating that these were from pyrogenic sources (such as coal and biomass combustion, and vehicle emissions) and coke oven emission distinguished as the main source of PAHs in the Songhua River Basin. Based on the ingestion of PAH-contaminated drinking water from the Songhua River, cancer risk was quantitatively estimated by combining the Incremental Lifetime Cancer Risk assessment model and BaP-equivalent concentration for five age groups of people (adults, teenagers, children, toddlers, and infants). Overall, the results suggest that the estimated integrated lifetime cancer risk for all groups was in acceptable levels. This study is the first attempt to provide information on the cancer risk of PAHs in drinking water from the Songhua River.

  4. Morphological characteristics of interactions between deserts and rivers in northern China

    NASA Astrophysics Data System (ADS)

    Yan, Ping; Li, XiaoMei; Ma, YuFeng; Wu, Wei; Qian, Yao

    2015-12-01

    Arid regions are affected by long-term interactions between various factors including water and wind. Recent research has concentrated on aeolian-fluvial interactions in dryland environments, including the important role of rivers in providing sand and spaces for deserts development, as well as the influences of aeolian activity upon river landforms. However, there is still a lack of comprehensive data at the large watershed scale to support such research. In this study, we analyzed statistically the morphological parameters related to twelve deserts and ten watersheds in dryland regions of northern China using remote sensing data, maps of desert and watershed distributions, and classification of aeolian landforms. Results indicate that, in view of the relationship between deserts and rivers, the geomorphic structures of drainage basins in northern China can be overall divided into five large drainage zones: northwestern drainage (ND), western drainage (WD), drainage of northern Qinghai-Tibet Plateau (PD), middle drainage (MD) and eastern drainage (ED). In the terms of percent area of desert in drainages, it can be sequenced as WD > MD > ND > ED > PD. For percent area of shifting dunes in deserts, WD > PD > MD > ED > ND. Considering the classification of aeolian dunes, transverse dune dominates in all drainages, and its proportion can be sorted as PD > ED > MD > WD > ND. There is a significant difference in their morphological parameters between interior and exterior watersheds. In exterior watersheds, desert area, shifting dune or transverse dune areas are not significantly associated with drainage area respectively, but interior watersheds have good correlations between them. And in three rivers of Tarim Basin, along with increasing distance from the river bank, the types of aeolian dune (complexity) increased step-wisely, implying that sand dune extends along the river terrace. Those data and preliminary findings confirm that the rivers are indispensable to the

  5. A hybrid model to simulate the annual runoff of the Kaidu River in northwest China

    NASA Astrophysics Data System (ADS)

    Xu, Jianhua; Chen, Yaning; Bai, Ling; Xu, Yiwen

    2016-04-01

    Fluctuant and complicated hydrological processes can result in the uncertainty of runoff forecasting. Thus, it is necessary to apply the multi-method integrated modeling approaches to simulate runoff. Integrating the ensemble empirical mode decomposition (EEMD), the back-propagation artificial neural network (BPANN) and the nonlinear regression equation, we put forward a hybrid model to simulate the annual runoff (AR) of the Kaidu River in northwest China. We also validate the simulated effects by using the coefficient of determination (R2) and the Akaike information criterion (AIC) based on the observed data from 1960 to 2012 at the Dashankou hydrological station. The average absolute and relative errors show the high simulation accuracy of the hybrid model. R2 and AIC both illustrate that the hybrid model has a much better performance than the single BPANN. The hybrid model and integrated approach elicited by this study can be applied to simulate the annual runoff of similar rivers in northwest China.

  6. No Red River capture since the late Oligocene: Geochemical evidence from the Northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Zhao, Meng; Shao, Lei; Liang, Jianshe; Li, Qianyu

    2015-12-01

    Rare earth elements (REE) in the sediment samples of six industrial wells from the Yinggehai-Song Hong Basin in the Northwestern South China Sea were analyzed and compared with the detrital zircon U-Pb data from earlier studies to extrapolate sediment provenance. The results reveal that the Red River (Song Hong River), Hainan Island and Central Vietnam have been the main provenances of the Yinggehai-Song Hong Basin since the late Oligocene. The Red River has been supplying sediments with positive Eu anomalies from basic-ultrabasic metamorphic and volcanic parent rocks to most parts of the basin, while Hainan Island has delivered sediments with negative Eu anomalies from granitic and sedimentary parent rocks to the eastern slope area of the basin. The progradational downlap structures in the seismic profiles also support the finding that the sediment supply is mainly from the Red River and from Hainan Island. The metamorphic rocks, which are widespread within the Red River drainage, not only provided high volumes of sediments to the basin but also contributed to the positive Eu anomalies observed. Because their REE and U-Pb signatures are similar to those of the Red River source, the metamorphic and igneous rocks of the Song Ma Suture Zone, Kontum Massif, and Jinghong area were probably parts of a large basic provenance region before being separated by strike-slip movements along the Ailao Shan-Red River shear zone. Furthermore, our results indicate that the Red River drainage area has been relatively stable since the late Oligocene. Therefore, if a drainage capture from the Red River occurred, it is likely to have taken place before the late Oligocene.

  7. Influence of small river derived sediment on the Northeastern South China Sea sedimentation processes in the last 40 K years

    NASA Astrophysics Data System (ADS)

    Cheng, Wan-Yen; Lin, Saulwood; Lou, Jiann-Yuh; Wei, Kuo-Yen; Liu, CharShine; Chen, Shing-Li; Wang, Yun-Shuen

    2015-04-01

    Small rivers derived particles are major source of sediment to the ocean in the present time. Small rivers in Taiwan are subjected to fast tectonic activity, high precipitation rate and erosion rate. The combined annual river particle load from small rivers on the Island of Taiwan is higher than that of the Mississippi River. A large fraction of those rivers particle may finding its way into the surrounding seas and ocean, e.g. South China Sea, East China Sea, and the Philippine Sea. Furthermore, due to the nature of particle transportation off rivers from Taiwan were connected by a number of canyon systems close by the river mouth, majority of those river particles were facilitated in delivering and deposited later further into the South China Sea deep basin. The objectives of this study are to understand spatial variations in sedimentation rates and to resolve the temporal differences in sedimentation in the Northeastern South China Sea region, and to evaluate influence of small river particles to the marginal sea. A set of cores was collected in overlying water depth within 1600 - 3300 m for mutilsensor core logging of magnetic susceptibility, density, and porosity. Foraminifera (G. sacculifer, G. conglobatus, O. universa) were picked and AMS C14 analyses for age determination. Grain size, organic carbon, carbonate and biogenic silica content were measured. The results show that large sedimentation rates difference existed in the study area. Earlier studies on sedimentation rate in the region west of our study area were in range of about 10 cm/kyr while our rates are about 20-40 cm/kyr and much higher near Taiwan. Bulk sedimentation rate were higher during the transition period between LGM and Holocene and lower during Holocene. Our results demonstrated that large quantity of particles from small rivers in Taiwan are and were major source of particle and are the dominating factor in controlling sediment deposition in the northeastern South China Sea.

  8. Toxicity bioassays for water from black-odor rivers in Wenzhou, China.

    PubMed

    DeFu, He; RuiRui, Chen; EnHui, Zhu; Na, Chen; Bo, Yang; HuaHong, Shi; MinSheng, Huang

    2015-02-01

    Following urbanization, a large number of urban rivers were contaminated and turned to black-odor rivers. The traditional approach for detecting water quality is based on chemical or physical analysis. However, biological toxicity of black-odor water has been less addressed. As two typical black-odor rivers, Jiushanwai River (JS) and Shanxia River (SX) are tributaries of Wen-Rui Tang River in Wenzhou (south of China). The eco-safety of the urban rivers was evaluated by bioassay for water toxicity in this study. Ten and 5 sampling sites were respectively set along JS and SX. Water samples were collected monthly from October 2010 to October 2011. The general physical and chemical parameters of river water were monitored. In order to investigate the ecotoxicological effects of black-odor water, the following bioassays were used: (1) Fish acute toxicity test (Danio rerio, comprehensive toxicity), (2) luminescent bacteria bioassay (Qinghaiensis vibrio, toxicity to bacteria), and (3) tropical claw embryo assay (Xenopus tropicalis, embryo toxicity). Biotoxicity of black-odor rivers water was demonstrated by D. rerio, Q. vibrio, and X. tropicalis embryos. Toxicological effects of black-odor water were respectively shown by mortality of zebrafish, and by the relative inhibitory light rate of luminescent bacteria. However, luminescent bacteria were more sensitive to inspect biotoxicity than zebrafish. In X. tropicalis embryos test, toxicological effects of black-odor water were mostly shown by embryos' survival rate and teratogenic rate. Bioassay results showed that toxicity of SX water was higher than that of JS water, especially in summer. Statistical analysis of luminescent bacteria toxicity test showed that biotoxicity of SX and JS was high in summer, but low in winter and spring. The seasonal changes of water toxicity of the black-odor river were positively correlative with changes of water temperature (p < 0.05), and related to pH and ammonium nitrogen of water

  9. 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. PMID:17160441

  10. 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

  11. Ecosystem Health Assessment of Urban Water Systems in Haihe River Basin, People's Republic of China

    NASA Astrophysics Data System (ADS)

    Liu, J.; Zhang, F.; Li, Y.

    2007-05-01

    The Haihe River Basin contains large urban centers and a significant portion of the population of China. The assessment of ecosystem health of urban water systems is the scientific basis for the basin water resources management and ecological restoration. An indicator system was developed for the ecosystem and landscape, which contains three levels. It uses the weighted average fuzzy synthetic evaluation method to assess the health status of urban water systems in order to diagnose the restriction factors of ecosystem health. As a case study in Beijing, the results indicated that the Nanchang River was in a healthy state, the degree of membership belonging to the healthy state was 0.417. In contrast, the Yongding River, the Beihucheng River and the Liangma River were in an unhealthy state; their degrees of membership were 0.585, 0.854 and 0.901 respectively. Much attention should be paid to the urban water systems in the Haihe River Basin, especially for the evaluated systems with an unhealthy state index of over 0.8. These urban water system are very important for the overall integrity of the basin ecosystem.

  12. Effects of the Changjiang (Yangtze) River discharge on planktonic community respiration in the East China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Chung-Chi; Shiah, Fuh-Kwo; Chiang, Kuo-Ping; Gong, Gwo-Ching; Kemp, W. Michael

    2009-03-01

    Planktonic communities tend to flourish on the western margins of the East China Sea (ECS) fueled by substrates delivered largely from the Changjiang River, the fifth largest river in the world. To study the effects of the Changjiang River discharge on planktonic community respiration (CR), physical-chemical variables and key processes were measured in three consecutive summers in the ECS. Results showed that concentrations of nitrate and Chl a, protozoan biomass, bacterial production, as well as CR in the surface water were all negatively correlated with sea surface salinity, reflecting the strong influence of river discharge on the ECS shelf ecosystem. Moreover, mean values of nitrate, Chl a concentrations, and CR rates were proportionally related to the area of Changjiang diluted water (CDW; salinity ≤31.0 practical salinity units (psu)), an index of river discharge rate. Presumably, higher river flow delivers higher nutrient concentrations which stimulate phytoplankton growth, which in turn fuels CR. CR exhibited significant monthly and interannual variability, and rates appear to be dominated by bacteria and phytoplankton. Although the plankton community was relatively productive (mean = 0.8 mg C m-2 d-1) in the CDW, the mean ratio of production to respiration was low (0.42). This suggests that the heterotrophic processes regulating CR were supported by riverine organic carbon input in addition to in situ autotrophic production.

  13. [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.

  14. Distribution and fate of synthetic musks in the Songhua River, Northeastern China: influence of environmental variables.

    PubMed

    Lu, Binyu; Feng, Yujie; Gao, Peng; Zhang, Zhaohan; Lin, Nan

    2015-06-01

    Contamination levels and spatial and temporal distributions of six typical synthetic musks (SMs) in water and sediment of the Songhua River in Northeastern China were investigated. Experimental data for 72 water and 52 sediment samples collected at 29 sampling sites over 12 months spanning 2011-2012 showed that the Songhua River had been contaminated to different degrees at various sites separately from the river's source. The polycyclic musks 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB) (Galaxolide) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) (Tonalide) were found most frequently and at the highest levels. Concentrations of HHCB were <2-37 ng/L in water and <0.5-17.5 ng/g dry weight (dw) in sediment. AHTN was <1-8 ng/L in water and <0.5-5.7 ng/g dw in sediment. Statistical relationships between SM concentrations and four environmental variables (temperature, illumination, runoff, and population density) in the Songhua River Basin were formulated. Concentration levels varied proportionately with the size of the city along the river, while the distribution patterns showed clear seasonal variations. HHCB/AHTN ratios mirrored the transfer and transmitting process of SMs. Concentrations of target compounds were correlated with each other, suggesting similar exposure sources. Environmental risk assessment of SMs presented seasonal variations and provided baseline information on SM exposure in the Songhua River Basin.

  15. Impacts of urbanization on hydrology in the Yangtze River Delta, China.

    PubMed

    Youpeng, Xu; Jintao, Xu; Jinjia, Ding; Ying, Chen; Yixing, Yin; Xingqi, Zhang

    2010-01-01

    The Yangtze River Delta is one of the most developed regions in China and the rapid development of urbanization have greatly influenced regional hydrology and water resources. Taking several typical urbanizing areas in the Yangtze River Delta as examples, this paper probes into the impacts of urbanization on hydrologic cycle and hydrological process with the support of RS, GIS and hydrological model. The research centers on the impacts of urbanization on precipitation, hydrological process, river networks, and water environment in some typical cities. The results show that: (1) Urban rain island effect is not evident when the process of urbanization is slow, while the differences of annual precipitation and flood season precipitation between urban and suburban areas increased to a certain extent in the booming stage of urbanization. (2) The annual runoff depth and the runoff coefficient increased with the development of urbanization, and the effect will be more notable when the urban areas expand to a certain size; (3) River network systems, especially low-grade rivers have been greatly destroyed in the process of urbanization, which increases the risk of flood and water degradation, so it is very important to protect natural river systems. Based on the results, some proposals of sustainable utilization and protection of water resources is also addressed.

  16. [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. PMID:27112020

  17. Classification of groundwater contamination in Yuxi River Valley, Shaanxi Province, China.

    PubMed

    Li, Yunfeng; Wan, Weifeng; Song, Jin; Wu, Yaoguo; Xu, Yanjuan; Zhang, Maosheng

    2009-02-01

    This study investigated groundwater contamination in the Yuxi River Valley in northern Shaanxi Province, one of largest energy resource centers in China. Groundwater samples collected from 129 locations in the Yuxi River Valley area were analyzed and evaluated to establish the local groundwater quality zonings. Results indicate that groundwater in the Yuxi River Valley is contaminated, and the dominant contaminants in the groundwater are ammonium (NH(4)(+)) and nitrite (NO(2)(-)). Maximal concentration of NH(4)(+) was detected at 0.019 and 3.50 mg/L in the samples collected up-gradient and down-gradient, respectively, of the segment of Yuxi River that flows through Yulin City. Concentration of NO(2)(-) was detected at 0.0015 and 1.522 mg/L, respectively from the same samples. Zones I through IV, from non-polluted to seriously polluted, were identified for groundwater quality in the Yuxi River Valley. We attribute the groundwater contamination in the Yuxi River valley to sources in the Yulin township, presumably its wastewater discharge.

  18. 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.

  19. 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.

  20. 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

  1. 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. PMID:22955725

  2. Study of sedimentation zones in a large sand-bed braided river: an example from the Hanjiang River of China

    NASA Astrophysics Data System (ADS)

    Jiongxin, Xu

    1997-12-01

    The concept of sedimentation zone is applied to the study of spatial and temporal variations of mid-channel bars in the middle Hanjiang River, a large sand-bed braided river in China. The river channel can be divided into alternating sedimentation zones and transport zones, the formation of which is basically controlled by local channel boundary conditions such as natural and artificial bank controls (bedrock outcrops, local hill spurs, terraces, artificial dikes and influence of tributaries). A systematic comparison between sedimentation and transport zones is made in this study, including the flow shear stress, stream power, mid-channel bar features and channel stability. The results obtained indicate that different channel boundary conditions in sedimentation and transport zones control channel width and width-depth ratio, which in turn control the reach's hydraulic and sediment transport characteristics. The storage and removal of sediment in sedimentation zones correspond to the increase and decrease of the degree to which mid-channel bars develop. When the sediment input of the channel system is altered by reservoir construction, the bed-load sediment historically accumulated is released by clear water scour, thus a macroscopic bed-load `wave' forms and moves gradually downstream. Associated with this is the complex response phenomenon of mid-channel bar evolution.

  3. Assessing temporal and spatial alterations of flow regimes in the regulated Huai River Basin, China

    NASA Astrophysics Data System (ADS)

    Zhang, Yongyong; Zhai, Xiaoyan; Shao, Quanxi; Yan, Ziqi

    2015-10-01

    The assessment of flow regime alterations is fundamental in understanding the potential impact of reservoirs and other water infrastructures on aquatic ecosystems and biota. Previously used methods to classify flow regimes have not captured temporal changes between unregulated and regulated flow regimes at individual stations. In this study, a combination of hierarchical classification and trend analysis was used to assess spatial and temporal flow regime alterations in the Huai River Basin, China. Two categories of flow regime indices were selected to characterize the impacts of reservoir and sluice regulation, including the basic flow indices for mean variation, and the cumulative variation indices for long-term alteration. The overall impact of reservoirs and sluices on flow regime included the decrease of high flow magnitudes but the increase of low flow magnitudes through time. Moreover, on average, the flow variability, and the high and low flow frequencies were reduced, while their durations were increased. Reservoirs had a greater impact on flow regimes than sluices. The flow regimes at 18 of 30 stations were altered significantly from a pre-regulation condition and were divided into three main types of alteration corresponding to operational rules of reservoirs and sluices. From a management perspective, water projects in China should address the environmental flow requirements of the rivers, particularly in terms of the hydrologic indices affected mostly by reservoirs and sluices. This study will promote the application of flow regime classification and river restoration in highly regulated basins in China.

  4. Occurrence and behavior of antibiotics in water and sediments from the Huangpu River, Shanghai, China.

    PubMed

    Chen, K; Zhou, J L

    2014-01-01

    This study aims to determine the occurrence and behavior of five classes of 20 antibiotics in both water and sedimentary phases in the Huangpu River, which supplies drinking water to Shanghai City, China. Of the 20 antibiotics, sulfonamides showed the highest concentrations in water samples (34-859 ng L(-1)) while tetracyclines (average concentration at 18 μg kg(-1) dry weight) and macrolides (12 μg kg(-1) dry weight) dominated in sediment samples. The spatial distribution of antibiotics showed that the main polluting sources into the river were animal farming sites and the tributaries downstream of the Yuanxie River. In addition, linear relationships between logKoc and logKow, and between logKoc and log molecular weight, were demonstrated, suggesting the importance of contaminant properties in inter-phase behavior. The environmental risk assessment revealed that some antibiotics, in particular sulfamethoxazole could cause medium damage to daphnid in the aquatic ecosystem.

  5. Recovery from Mercury Contamination in the Second Songhua River, China

    PubMed Central

    Zhang, Z. S.; Sun, X. J.; Wang, Q. C.; Zheng, D. M.; Zheng, N.

    2009-01-01

    Mercury pollution in the Second Songhua River (SSR) was serious in the last century due to effluent from a chemical corporation. Effects of riverine self-purification on mercury removal were studied by comparing monitoring data of mercury concentrations varieties in water, sediment, and fish in the past, about 30 years. The present work suggested that a river of such a size like the SSR possessed the potential ability to recover from mercury pollution under the condition that mercury sources were cut off, though it needs a very long time, which might be several decades or even a century of years. During the 30 years with no effluent containing mercury input, total mercury (T-Hg) of water and sediment in some typical segments, mostly near the past effluent outlet, had decreased radically but still higher than the background values, though the decrease amplitudes were over 90% compared with that in 1975. T-Hg had decreased by more than 90% in most fishes, but some were still not suitable for consumption. Methylmercury concentrations (MeHg) of water, sediment, and fish were higher or close to the background levels in 2004. In the coming decades, the purification processes in the SSR would be steady and slow for a long period. PMID:20835296

  6. Response of surface water acidification in upper Yangtze River to SO2 emissions abatement in China.

    PubMed

    Duan, Lei; Ma, Xiaoxiao; Larssen, Thorjørn; Mulder, Jan; Hao, Jiming

    2011-04-15

    Surface waters in Europe and North America are slowly recovering from acidification following major reductions in emissions of sulfur dioxide (SO(2)) since the 1980s. In contrast, regions affected by acid rain have been reported to be growing in China. Here we show that the rapid change in surface water chemistry in the 1990s in large areas in Southwestern China, specifically the tributary rivers of the Upper Yangtze River, caused by increasing SO(2) emissions, has leveled off. During the 1990s the sulfate (SO(4)(2-)) concentrations in river water increased rapidly and, on average, doubled in only eight years. Simultaneously, calcium (Ca(2+)) concentrations increased, while pH values decreased. In the following decade (2000s), SO(2) emissions stabilized, causing a subsequent stop to the increasing SO(4)(2-) concentrations and pH decline in river water. Although a rapid response to future reduction in SO(2) emissions can be expected, a rapid increase of nitrogen (N) emissions could lead to increases in N leaching and delay recovery.

  7. Response of surface water acidification in upper Yangtze River to SO2 emissions abatement in China.

    PubMed

    Duan, Lei; Ma, Xiaoxiao; Larssen, Thorjørn; Mulder, Jan; Hao, Jiming

    2011-04-15

    Surface waters in Europe and North America are slowly recovering from acidification following major reductions in emissions of sulfur dioxide (SO(2)) since the 1980s. In contrast, regions affected by acid rain have been reported to be growing in China. Here we show that the rapid change in surface water chemistry in the 1990s in large areas in Southwestern China, specifically the tributary rivers of the Upper Yangtze River, caused by increasing SO(2) emissions, has leveled off. During the 1990s the sulfate (SO(4)(2-)) concentrations in river water increased rapidly and, on average, doubled in only eight years. Simultaneously, calcium (Ca(2+)) concentrations increased, while pH values decreased. In the following decade (2000s), SO(2) emissions stabilized, causing a subsequent stop to the increasing SO(4)(2-) concentrations and pH decline in river water. Although a rapid response to future reduction in SO(2) emissions can be expected, a rapid increase of nitrogen (N) emissions could lead to increases in N leaching and delay recovery. PMID:21449576

  8. 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. PMID:26178666

  9. Probabilistic forecasting of seasonal drought behaviors in the Huai River basin, China

    NASA Astrophysics Data System (ADS)

    Xiao, Mingzhong; Zhang, Qiang; Singh, Vijay P.; Chen, Xiaohong

    2016-01-01

    The Huai River basin is one of the major supplier of agricultural products in China, and droughts have critical impacts on agricultural development. Good knowledge of drought behaviors is of great importance in the planning and management of agricultural activities in the Huai River basin. With the copula functions to model the persistence property of drought, the probabilistic seasonal drought forecasting models have been built in the Huai River basin. In this study, droughts were monitored by the Standardized Precipitation Evapotranspiration Index (SPEI) with the time scales of 3, 6, and 9 months, and their composite occurrence probability has been used to forecast the seasonal drought. Results indicated that the uncertainty related to the predicted seasonal drought is larger when more severe droughts occurred in the previous seasons, and the severe drought which occurs in summer and autumn will be more likely to be persistent in the next season while the severe drought in winter and spring will be more likely to be recovered in the subsequent season. Furthermore, given the different drought statuses in the previous season, spatial patterns of the predicted drought events with the largest occurrence probability have also been investigated, and results indicate that the Huai River basin is vulnerable to the extreme drought in most parts of the basin, e.g., the severe drought in winter will be more likely to be persistent in spring in the central part of the southern Huai River basin. Such persistent drought events pose serious challenges for planning and management of agricultural irrigation, then results of the study will be valuable for the planning of crop cultivation or mitigation of the losses caused by drought in the Huai River basin, China.

  10. Incision Along the Red River, Yunnan Province, China: a Transient Response to Regional Surface Uplift

    NASA Astrophysics Data System (ADS)

    Schoenbohm, L. M.; Whipple, K. X.; Burchfiel, B. C.; Chen, L.

    2002-12-01

    On the basis of digital elevation data and field observations, we observe a low-relief relict landscape in the vicinity of the Red River, Yunnan Province, China, which correlates to a regional erosion surface preserved over the eastern margin of the Tibetan Plateau (Clark et al. 2002). As with other major rivers of the eastern margin, the Red River has incised the relict landscape, creating a river valley system up to 2 km deep, which we refer to as the active landscape. Abandonment of the relict landscape and subsequent river incision is likely related to surface uplift from inflation of regions adjacent to the Tibetan Plateau by pressure-gradient driven flow of lower crust from beneath Tibet (Clark and Royden, 2000). The relict landscape is preserved as low-relief patches along the margins of the of the Red River basin; however, this is a transient state. If the new conditions (change in uplift rate) persist over a long enough timescale, full equilibration to the active landscape will occur and the relict landscape will be destroyed. We examine the expression of the transient condition in the Red River basin, using longitudinal river profiles for 102 tributaries to the Red River. Most profiles consist of an upper channel with low steepness and normal concavity, and a lower channel with high steepness and concavity, separated by a sharp knickpoint. The upper channel portions correspond to the relict landscape and have not yet felt the effect of river incision. Below the knickpoint the channels are incising rapidly. Extremely high concavities in the lower channel segments likely result from a complicated regional incision history. We argue that rapid regional surface uplift, followed by slower surface uplift and a correspondent decrease over time in uplift rate is responsible for the overall river incision pattern and in particular for the high concavities in the lower channel segments. However, this conclusion is complicated by the effects of changing erosion

  11. 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

    2016-06-01

    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

  12. Fluvial responses to late Quaternary climate change in the Shiyang River drainage system, western China

    NASA Astrophysics Data System (ADS)

    Gao, Hongshan; Li, Zongmeng; Pan, Baotian; Liu, Fenliang; Liu, Xiaopeng

    2016-04-01

    As a drainage system located in arid western China, the Shiyang River, combined with considerable fluvial strata and landform information, provides an environmental context within which to investigate fluvial responses to late Quaternary climate change. Sedimentological analysis and optically stimulated luminescence (OSL) dating enabled us to reconstruct the processes and fluvial styles of three sedimentary sequences of the Shagou and Hongshui rivers in the Shiyang drainage system. Our results present a variety of river behaviors during the late Quaternary in these areas. In the upstream Shiyang River, Zhangjiadazhuang (ZJDZ) profile of the Shagou was dominated by aggradation and a meandering channel pattern at 10.6-4.2 ka, while a noticeable channel incision occurred at ~ 4.2 ka followed by lateral channel migration. In the downstream Shiyang River, Datugou (DTG) profile of the Hongshui was an aggrading meandering river from 39.7 to 7.2 ka while channel incision occurred at 7.2 ka. Another downstream profile, Wudunwan (WDW) of the Hongshui was also characterized by aggradation from 22.4 to 4.8 ka; however, its channel pattern shifted from braided to meandering at ~ 13 ka. A discernable downcutting event occurred at ~ 4.8 ka, followed by three channel aggradation and incision episodes prior to 1.8 ka. The last 1.8 ka has been characterized by modern channel and floodplain development. The fluvial processes and styles investigated have a close correlation with late Quaternary climate change in the Shiyang River drainage. During cold phases, the WDW reach was dominated by aggradation with a braided channel pattern. During warm phases, the rivers that we investigated were also characterized by aggradation but with meandering channel patterns. Channel incision events and changes of fluvial style occurred mainly during climate transitions.

  13. 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

  14. 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.

  15. Comparison of products from ERA-40, NCEP-2, and CRU with station data for summer precipitation over China

    NASA Astrophysics Data System (ADS)

    Zhao, T. B.; Fu, C. B.

    2006-07-01

    Summer precipitation products from the 45-Year European Centre for Weather Forecast (ECTMWF) Reanalysis (ERA-40), and NCEP-Department of Energy (DOE) Atmospheric Model Intercomparison Project (ATMIP-II) Reanalysis (NCEP-2), and Climatic Research Unit (CRU) TS 2.1 dataset are compared with the corresponding observations over China in order to understand the quality, and utility of the reanalysis datasets for the period 1979-2001. The results reveal that although the magnitude and location of the rainfall belts differ among the reanalysis, CRU, and station data over South and West China, the spatial distributions show good agreement over most areas of China. In comparison with the observations in most areas of China, CRU best matches the observed summer precipitation, while ERA-40 reports less precipitation and NCEP-2 reports more precipitation than the observations. With regard to the amplitude of the interannual variations, CRU is better than either of the reanalyses in representing the corresponding observations. The amplitude in NCEP-2 is stronger but that of ERA-40 is weaker than the observations in most study domains. NCEP-2 has a more obvious interannual variability than ERA-40 or CRU in most areas of East China. Through an Empirical orthogonal function (EOF) analysis, the main features of the rainfall belts produced by CRU aggree better with the observations than with those produced by the reanalyses in the Yangtze-Huaihe River valley. In East of China, particularly in the Yangtze-Huaihe River valley, CRU can reveal the quasi-biennial oscillation of summer precipitation represented by the observations, but the signal of ERA-40 is comparatively weak and not very obvious, whereas that of NCEP-2 is also weak before 1990 but very strong after 1990. The results also suggest that the magnitude of the precipitation difference between ERA-40 and the observations is smaller than that between NCEP-2 and the observations, but the variations represented by NCEP-2 are

  16. Verification and comparison of probabilistic precipitation forecasts using the TIGGE data in the upriver of Huaihe Basin

    NASA Astrophysics Data System (ADS)

    Zhao, L.-N.; Tian, F.-Y.; Wu, H.; Qi, D.; di, J.-Y.; Wang, Z.

    2011-03-01

    The precipitation forecasts of three ensemble prediction systems (EPS) and two multi-model ensemble prediction systems (MM EPS) were assessed by comparing with observations from 19 rain gauge stations located in the Dapoling-Wangjiaba sub-catchment of Huaihe Basin for the period from 1 July to 6 August 2008. The sample Probabilistic Distribution Functions (PDF) of gamma distribution, the Relative Operating Characteristic (ROC) diagrams, the percentile precipitation and a heavy rainfall event are analyzed to evaluate the performances of the single and multi-model ensemble prediction system (EPS). The three EPS were from the China Meteorological Administration (CMA); the United States National Centre for Environment Predictions (NCEP); and the European Centre for Medium-Range Weather Forecasts (ECMWF), all were obtained from the TIGGE-CMA archiving centre (THORPEX Interactive Grand Global Ensemble, TIGGE). The MM EPS were created using the equal weighting method for every ensemble member over the test area, the first ( MM-1) consisted of all three EPS, the second (MM-2) consisted of the ECMWF and NCEP EPS. The results demonstrate the level of correspondence between deterioration in predictive skill and extended lead time. Compared with observations and with a lead time of one day, ECMWF performs a little better than other centre's. With over five days in advance, all the three EPS and the two MM EPS don't give reliable probabilistic precipitation forecasts. Both MM EPS can outperform CMA and NCEP for most of the forecasted days, but still perform a little worse than ECMWF. Though variation of daily percentile precipitation and ROC areas show MM-2 outperforms MM-1, gamma distribution indicates much similar performances for all 10-day forecast, and neither is superior to ECMWF.

  17. 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

    2015-01-01

    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 × 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. PMID:26582206

  18. 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

  19. 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.

  20. Polycyclic aromatic hydrocarbons in riverine runoff of the Pearl River Delta (China): concentrations, fluxes, and fate.

    PubMed

    Wang, Ji-Zhong; Guan, Yu-Feng; Ni, Hong-Gang; Luo, Xian-Lin; Zeng, Eddy Y

    2007-08-15

    On the basis of a monthly sampling effort from March 2005 to February 2006, the total concentrations of the sums of 27 and 15 polycyclic aromatic hydrocarbons (defined as sigma27PAHs and sigma15PAHs, respectively) in riverine runoff of the Pearl River Delta (PRD), China, and associated fluxes were determined. No clear temporal and spatial trends of PAH concentrations were found at all eight riverine runoff outlets where the samples were collected. The annual fluxes of sigma27PAHs and sigma15PAHs from the PRD to the coastal ocean were 60.2 and 33.9 metric tons, respectively. Assuming that riverine flux was positively related to the regional emission of PAHs, the annual riverine fluxes from five major rivers in China to the global oceans were estimated, which are quite significant relative to other major rivers of the world. On the basis of mass balance considerations, approximately 87% of sigma15PAHs inputting to the Pearl River Estuary and northern South China Sea was derived from riverine runoff from the PRD. In addition, approcimately 22.3 metric tons of sigma15PAHs annually outflow to open seas, which is equivalent to a concentration of 0.34 pg/L in the global oceans if the PAHs are evenly distributed in the upper 200 m of the water column. A comparison with the global background level of PAHs indicated that approximately 0.4% of PAHs in the open oceans may have been contributed by 1-year discharge from the PRD.

  1. Predicting precipitation on nonpoint source pollutant exports in the source area of the Liao River, China.

    PubMed

    Wang, Y; Bian, J M; Wang, S N; Nie, S Y

    2016-01-01

    The source area of the Liao River is an important grain growing area in China which experiences serious problems with agricultural nonpoint source pollution (NPS) which is impacting the regional economy and society. In order to address the water quality issues it is necessary to understand the spatial distribution of NPS in the Liao River source area. This issue has been investigated by coupling a wavelet artificial neural network (WA-ANN) precipitation model with a soil and water assessment tool (SWAT) model to assess the export of nonpoint source pollutants from the Liao River source area. The calibration and validation of these models are outlined. The WA-ANN models and the SWAT model were run to generate the spatial distribution of nonpoint source nutrient (nitrogen and phosphorus) exports in the source area of the Liao River. It was found that the SWAT model identified the sub-catchments which not only receive high rainfall but are also densely populated with high agricultural production from dry fields and paddy fields, which are large users of pesticides and chemical fertilizer, as the primary source areas for nutrient exports. It is also concluded that the coupled WA-ANN models and the SWAT model provide a tool which will inform the identification of NPS issues and will facilitate the identification of management practices to improve the water environments in the source area of the Liao River.

  2. [Content analysis and assessment of polycyclic aromatic hydrocarbons in surface sediments from Beijiang River, China].

    PubMed

    Xu, Jing; Ren, Ming-Zhong; Du, Gou-Yong; Zhang, Su-Kun; Xu, Zhen-Cheng

    2009-11-01

    In the present study, 16 polycyclic aromatic hydrocarbons (PAHs) in the surface sediment from Beijiang River in China were quantitatively determined by GC/MS. The concentration of PAHs varied from 38.2 to 6470 ng x g(-1) dry weight, with average 1071 ng x g(-1), which was in moderate level compared with other rivers in Pear River Basin. The PAHs distribution in Bejiang River was obviously affected by point source emissions. The high PAHs concentrations of 6470 ng x g(-1) and 4 470 ng x g(-1) were found at the outfalls of Shaoye and the Shakou town, respectively, where PAHs probably derived from local mining/smelting and related industrial actives. The ecological risk of surface sediment in Beijiang River was assessed with the methods of sediment quality guidelines (SQGs), sediment quality standards (SQSs) and contamination factors (CFs) . The result shows that the adverse biological toxicity effect might occasionally happen in more than half of sampling stations. By comparison with the background area, the contamination degrees of PAHs in 20 sampling stations were at very high level, which should arrest the local governments' attentions. The highest ecological risk areas occurred at the outfalls of Shaoye and the Shakou town in which the ecological risks derived from PAHs were within between probable effect level (PEL) and frequent effect level (FEL). The future research was suggested mainly focusing on the status of benthos, sources of pollutants and ways to control pollution in high-risk areas. PMID:20063739

  3. 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. PMID:27026547

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

    PubMed

    Wang, Ce; Cyterski, Mike; Feng, Yujie; Gao, Peng; Sun, Qingfang

    2015-11-01

    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 loadings of organic contaminants along an industrialized section have made it the focal point of a national pollution reduction plan. In addition to water quality issues, management of the Songhua River basin must also address local economic development, aquatic ecosystem sustainability and political relationships with Russia. In three periods spanning 2006 to 2010, eight polycyclic aromatic hydrocarbons (PAHs) and eight phenols were measured in surface waters at ten monitoring sites along the river. A generalized linear model (GLM) was used to characterize water quality at different sites and time periods. Chemical concentrations of the organic compounds showed significant sinusoidal seasonal patterns and the concentrations declined significantly from 2006 to 2010, possibly due to management practices designed to control water pollution. A critical body residue analysis showed that water concentrations measured during the winter of 2007 across all monitoring sites, but especially at S1-Shaokou and S2-Songhuajiangcun, presented a high risk for fish species. The spatiotemporal characteristics of water quality and estimated ecological risks shown here add to the body of knowledge to develop policies on industrial output and pollution management strategies for the Songhua River basin. PMID:26442573

  5. Identification of causative compounds and microorganisms for musty odor occurrence in the Huangpu River, China.

    PubMed

    Sun, Daolin; Yu, Jianwei; An, Wei; Yang, Min; Chen, Guoguang; Zhang, Shujun

    2013-03-01

    There are regular problems of musty odor in the Huangpu River, a major source of drinking water for Shanghai, China. In this study, the musty odor and its main causative compounds in the Huangpu River source water were confirmed through a yearly investigation using flavor profile analysis combined with HSPME-GC-MS analysis. The investigation showed that 2-methylisoborneol (2-MIB) with a concentration level between 28.6 and 71.0 ng/L was responsible for the musty odor in summer from July to September. Microscopic observation confirmed with the cloning results showed that Phormidium spp., which accounted for 80%-95% of the algal cell density, was the microorganisms responsible for the production of 2-MIB and the estimated 2-MIB yield was 0.022 pg/cell. Results from a wide-area sampling campaign in the Huangpu River watershed showed that, other than the large tributaries receiving water from Tai Lake, several small creeks close to the intake may have contributed most of the 2-MIB and the Phormidium spp. to the Huangpu River source water. This study provides methodology for the investigation of odor causing compounds and microorganisms in river-type source water, and the result will be useful for water quality control in both source water and drinking water.

  6. 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.

  7. 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

  8. 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.

  9. Y Chromosome analysis of prehistoric human populations in the West Liao River Valley, Northeast China

    PubMed Central

    2013-01-01

    Background The West Liao River valley in Northeast China is an ecologically diverse region, populated in prehistory by human populations with a wide range of cultures and modes of subsistence. To help understand the human evolutionary history of this region, we performed Y chromosome analyses on ancient human remains from archaeological sites ranging in age from 6500 to 2700 BP. Results 47 of the 70 individuals provided reproducible results. They were assigned into five different Y sub-haplogroups using diagnostic single nucleotide polymorphisms, namely N1 (xN1a, N1c), N1c, C/C3e, O3a (O3a3) and O3a3c. We also used 17 Y short tandem repeat loci in the non-recombining portion of the Y chromosome. There appears to be significant genetic differences between populations of the West Liao River valley and adjacent cultural complexes in the prehistoric period, and these prehistoric populations were shown to carry similar haplotypes as present-day Northeast Asians, but at markedly different frequencies. Conclusion Our results suggest that the prehistoric cultural transitions were associated with immigration from the Yellow River valley and the northern steppe into the West Liao River valley. They reveal the temporal continuity of Y chromosome lineages in populations of the West Liao River valley over 5000 years, with a concurrent increase in lineage diversity caused by an influx of immigrants from other populations. PMID:24079706

  10. Correlations between zooplankton assemblages and environmental factors in the downtown rivers of Shanghai, China

    NASA Astrophysics Data System (ADS)

    Yu, Na; Li, Erchao; Feng, Dexiang; Xiao, Baicai; Wei, Chaoqun; Zhang, Meiling; Chen, Liqiao

    2014-11-01

    Most urban rivers play an important role in urban flood control and drainage in China, but pollution is fast becoming an issue of greater importance in water management. In this study, 63 zooplankton species were recorded in four downtown rivers in Shanghai between November 2007 and October 2008. Of these, 44 species belonged to the Rotifera, 13 to Cladocera, and six to Copepoda. The three most frequently occurring zooplankton ( Brachionus calyciflorus, Microcyclops leuckarti, and Asplanchna priodonta) accounted for 80.00%, 76.84%, and 53.68%, respectively. Rotifera were found to be dominant, comprising 86.26% of total zooplankton, while cladoceran and copepod abundance amounted to 5.08% and 8.67%, respectively. Water temperature, salinity, electrical conductivity, and total nitrogen were of the greatest significance in the occurrence of zooplankton. Two species ( Schmackeria forbesi and Lepadella ovalis) were notably more sensitive to environmental factors such as salinity and electrical conductivity than other species. The population size and community were inversely correlated with the increasing nutrient levels of the four rivers, suggesting that the water quality of the four rivers had been gradually recovering from a severe eutrophic state and that water conditions of the rivers had been gradually improved.

  11. 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.

  12. Heavy metal accumulation by periphyton is related to eutrophication in the Hai River Basin, Northern China.

    PubMed

    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.

  13. Predicting precipitation on nonpoint source pollutant exports in the source area of the Liao River, China.

    PubMed

    Wang, Y; Bian, J M; Wang, S N; Nie, S Y

    2016-01-01

    The source area of the Liao River is an important grain growing area in China which experiences serious problems with agricultural nonpoint source pollution (NPS) which is impacting the regional economy and society. In order to address the water quality issues it is necessary to understand the spatial distribution of NPS in the Liao River source area. This issue has been investigated by coupling a wavelet artificial neural network (WA-ANN) precipitation model with a soil and water assessment tool (SWAT) model to assess the export of nonpoint source pollutants from the Liao River source area. The calibration and validation of these models are outlined. The WA-ANN models and the SWAT model were run to generate the spatial distribution of nonpoint source nutrient (nitrogen and phosphorus) exports in the source area of the Liao River. It was found that the SWAT model identified the sub-catchments which not only receive high rainfall but are also densely populated with high agricultural production from dry fields and paddy fields, which are large users of pesticides and chemical fertilizer, as the primary source areas for nutrient exports. It is also concluded that the coupled WA-ANN models and the SWAT model provide a tool which will inform the identification of NPS issues and will facilitate the identification of management practices to improve the water environments in the source area of the Liao River. PMID:27533862

  14. Land use/land cover change in Yellow River Delta, China during fast development period

    NASA Astrophysics Data System (ADS)

    Zhou, Wenzuo; Tian, Yongzhong; Zhu, Lifen

    2007-09-01

    Terrestrial eco-system in coastal zones is unstable and land-use and Land-cover of its land resource are crucial for its sustainability. Therefore it is necessary to understand distribution of land use/cover changes in those tender areas. This paper was to analyze changes of land use/cover in Yellow River Delta in China during recent ten years, which was its fast development period, by remote sensing monitoring. Two Landsat TM images in October of 1995 and 2004 were processed using ERDAS software and supervised classification method in study for the land use and land cover of those two years. The two land use/cover maps were overlaid to discover the changes. It was showed that lots of land use/cover changes in the Yellow River Delta had taken place in past ten years. Because abundant sand that carried by river water filled up at estuary of the Yellow River, new land increased fleetly. The rates that foreshore were turned into fishery land was high for aquaculture with salt water had been developed quickly. Another important effect of human activity was that part of waste land and grassland had been cultivated for crops. With industry and economy development, land for urbanization had been outspreaded. Although fast exploitation had been carried out in Yellow River Delta going though those years, some human activities on land use were inharmonious for sustainable development of land resource in this area. This must be pay attention to by local government and people.

  15. Assessment of sampling designs to measure riverine fluxes from the Pearl River Delta, China to the South China Sea.

    PubMed

    Ni, Hong-Gang; Lu, Feng-Hui; Luo, Xian-Lin; Tian, Hui-Yu; Wang, Ji-Zhong; Guan, Yu-Feng; Chen, She-Jun; Luo, Xiao-Jun; Zeng, Eddy Y

    2008-08-01

    The Pearl River Delta (PRD), located in South China and adjacent to the South China Sea, is comprised of a complicated hydrological system; therefore, it was a great challenge to sample adequately to measure fluxes of organic and inorganic materials to the coastal ocean. In this study, several sampling designs, including five-point (the number of sampling points along the river cross-section and three samples collected at the upper, middle, and bottom parts at each vertical line), three-point (at the middle and two other profiles), one-point (at the middle profile), and single-point (upper, middle, or bottom sub-sampling point at the middle profile) methods, were assessed using total organic carbon (TOC) and suspended particulate matter (SPM) as the measurables. Statistical analysis showed that the three- and five-point designs were consistent with one another for TOC measurements (p > 0.05). The three- and one-point sampling methods also yielded similar TOC results (95% of the differences within 10%). Single-point sampling yielded considerably larger errors than the three- and one-point designs, relative to the results from the five-point design, but sampling at the middle sub-point from the middle profile of a river achieved a relatively smaller error than sampling at the upper or bottom sub-point. Comparison of the sampling frequencies of 12 times a year, four times a year, and twice a year indicated that the frequency of twice a year was sufficient to acquire representative TOC data, but larger sample size and higher sampling frequency were deemed necessary to characterize SPM.

  16. [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.

  17. Plant community succession in modern Yellow River Delta, China*

    PubMed Central

    Zhang, Gao-sheng; Wang, Ren-qing; Song, Bai-min

    2007-01-01

    Data were collected in different successional stages using a simultaneous sampling method and analyzed through quantitative classification method. Three large groups and 12 classes were made to represent the community patterns of three succession stages and 12 succession communities. The succession series of plant community in the study area was as follows: saline bare land→community Suaeda salsa→community Tamarix chinensis→grassland. Succession degree and succession process of 12 succession communities were calculated. Most of these communities were in the lower succession stage, however, community Phragmites communis+Glycine soja and community Imperata cylindrica+G. soja were close to the succession stage of grassland climax. Five species diversity indices were used to study the changes in species richness, species evenness and diversity during succession of community. Heterogeneity index and richness index increased gradually during the community succession process, but species evenness tended to decrease with succession development. The relation between succession and environment was studied by ordination technique, and the results showed that the soil salt content was an important factor to halarch succession of the modern Yellow River Delta. It affected community structure, species composition and succession process. PMID:17657854

  18. Progress, challenges and prospects of eco-hydrological studies in the Tarim river basin of Xinjiang, China.

    PubMed

    Chen, Yaning; Xu, Changchun; Chen, Yapeng; Liu, Yongbo; Li, Weihong

    2013-01-01

    Eco-hydrological research in arid inland river basins has been a focus of geologists and ecologists as it is crucial for maintaining the sustainable development of socio-economy, particularly in ecologically vulnerable areas. Based on the research work carried out in the Tarim River basin of Xinjiang, northwestern China, this paper summarizes synthetically the climate change and associated responses of water resources in the mountainous area, land use and land cover in the oasis, and plants responding to environmental stresses in the desert area of the river basin. Research gaps, challenges, and future perspectives in the eco-hydrological studies of the Tarim River basin are also discussed. PMID:22392285

  19. Progress, challenges and prospects of eco-hydrological studies in the Tarim river basin of Xinjiang, China.

    PubMed

    Chen, Yaning; Xu, Changchun; Chen, Yapeng; Liu, Yongbo; Li, Weihong

    2013-01-01

    Eco-hydrological research in arid inland river basins has been a focus of geologists and ecologists as it is crucial for maintaining the sustainable development of socio-economy, particularly in ecologically vulnerable areas. Based on the research work carried out in the Tarim River basin of Xinjiang, northwestern China, this paper summarizes synthetically the climate change and associated responses of water resources in the mountainous area, land use and land cover in the oasis, and plants responding to environmental stresses in the desert area of the river basin. Research gaps, challenges, and future perspectives in the eco-hydrological studies of the Tarim River basin are also discussed.

  20. Recent heterogeneous warming and the associated summer precipitation over eastern China

    NASA Astrophysics Data System (ADS)

    Zhu, Jian; Huang, Dan-Qing; Dai, Ying; Chen, Xi

    2016-02-01

    The recent heterogeneous warming and the associated summer precipitation over eastern China are investigated in this study. In 1990-1999, there exist warming over northwestern Pacific and cooling over eastern equatorial Pacific, which can be quantified by temperature gradient index (TGI). Positive and negative cases are chosen based on TGI. In positive cases, a "southern flood and northern drought" summer rainfall pattern dominates over eastern China. The atmospheric circulations show that associated with the southward receding of western Pacific subtropical high (WPSH), ascending motion accompanied with more water vapor exists over southern China. Furthermore, cold-warm air activity affected by weakened East Asian subtropical jet (EASJ) and strengthened East Asia polar front jet (EAPJ) may also be responsible for this rainfall anomaly pattern. In negative cases, significant positive Meiyu-like rainfall anomaly concentrated over Yangtze Huaihe River Basin (YHRB). Associated with the northward shift of WPSH, more water vapor is transported to YHRB. Additionally, the enhanced ascending motion over YHRB may be related with the northward shift of the EAPJ and westward shift of the EASJ. The results reinforce the notion that the configuration of EASJ and EAPJ in both intensity and position has large impacts on the precipitation variations over eastern China.

  1. 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.

  2. Indicating appropriate groundwater tables for desert river-bank forest at the Tarim River, Xinjiang, China.

    PubMed

    Hao, Xing-Ming; Chen, Ya-Ning; Li, Wei-Hong

    2009-05-01

    Based on data collected over 2 years of monitoring the lower reaches of the Tarim River, the groundwater table depth was divided into six classes; 0 to 2 m, 2 to 4 m, 4 to 6 m, 6 to 8 m, 8 to 10 m, >10 m. We investigated the vegetation in this area to measure the influence of groundwater table depth on plant diversity and species ecological niche. The results indicated that plant diversity was highest at the 2 to 4 m groundwater table depth, followed by that at 4 to 6 m, and then that at 0 to 2 m. When the groundwater depth dropped to below 6 m, species diversity decreased dramatically, and the slope of Hill's index tended to level off. The ecological niche of the major species in this area initially expanded as the groundwater level dropped. The widest niche appeared at the 4 to 6 m groundwater table depth and gradually narrowed with deepening groundwater. Ecological niche analysis also revealed that the 4 to 6 m groundwater table depth was associated with the lowest degree of niche overlap and the richest variety of species. Our findings indicate that in the lower reaches of the Tarim River, the groundwater table depth must be a minimum of 6 m for vegetation restoration; it should be maintained at 2 to 4 m in the vicinity of the water path, and at 4 to 6 m for the rest of this arid area.

  3. Effects of in-channel sand excavation on the hydrology of the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Luo, Xian-Lin; Zeng, Eddy Y.; Ji, Rong-Yao; Wang, Chao-Pin

    2007-09-01

    SummaryThe hydrology and morphology of the Pearl River Delta (PRD; South China) water system has been predominantly dictated by human activities over the last 20 years. Uncontrolled sand excavation occurred in all 324 tributaries, largely to meet the construction needs arising from the rapid economic growth and urbanization in the region. It was estimated that >8.7 × 10 8 m 3 of sand were excavated from 1986 to 2003 based on field surveys of excavating activities and the river hypsography, resulting in average downcutting depths of 0.59-1.73 m, 0.34-4.43 m, and 1.77-6.48 m in the main channels of the West River, North River, and East River (three major water networks in the PRD), respectively. Consequently, the water levels in upstream of the PRD were decreased by 1.59-3.12 m (Sanshui Station). Uneven sand dredging also caused changes in the divided flow ratio (DFR) between various water courses. For example, the DFR increased by 8.8% at the Sanshui Station on the upper part of the North River network from the early 1980s to 1999. DFRs also increased almost 7.7% at the four major runoff outlets in the eastern side of the PRD. As a result, present brackish-water has intruded upward 10-20 km more than in the 1980s. Apparently, there are two sides to the effects of sand excavation. The positive effects are decreased chances of flooding damages, improved navigating conditions, and more water inputs to rapid economically growing regions. The negative effects include increased grade slope and instability of the riverbank, disruption of navigation in upstream dredging pits during dry seasons, and brackish-water intrusion.

  4. Distribution and fate of synthetic musks in the Songhua River, Northeastern China: influence of environmental variables.

    PubMed

    Lu, Binyu; Feng, Yujie; Gao, Peng; Zhang, Zhaohan; Lin, Nan

    2015-06-01

    Contamination levels and spatial and temporal distributions of six typical synthetic musks (SMs) in water and sediment of the Songhua River in Northeastern China were investigated. Experimental data for 72 water and 52 sediment samples collected at 29 sampling sites over 12 months spanning 2011-2012 showed that the Songhua River had been contaminated to different degrees at various sites separately from the river's source. The polycyclic musks 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB) (Galaxolide) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) (Tonalide) were found most frequently and at the highest levels. Concentrations of HHCB were <2-37 ng/L in water and <0.5-17.5 ng/g dry weight (dw) in sediment. AHTN was <1-8 ng/L in water and <0.5-5.7 ng/g dw in sediment. Statistical relationships between SM concentrations and four environmental variables (temperature, illumination, runoff, and population density) in the Songhua River Basin were formulated. Concentration levels varied proportionately with the size of the city along the river, while the distribution patterns showed clear seasonal variations. HHCB/AHTN ratios mirrored the transfer and transmitting process of SMs. Concentrations of target compounds were correlated with each other, suggesting similar exposure sources. Environmental risk assessment of SMs presented seasonal variations and provided baseline information on SM exposure in the Songhua River Basin. PMID:25874412

  5. 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

  6. 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

  7. 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%. PMID:26555797

  8. Eddy-entrained Pearl River plume into the oligotrophic basin of the South China Sea

    NASA Astrophysics Data System (ADS)

    He, Xianqiang; Xu, Dongfeng; Bai, Yan; Pan, Delu; Chen, Chen-Tung Arthur; Chen, Xiaoyan; Gong, Fang

    2016-08-01

    The South China Sea (SCS) is the world's largest tropical marginal sea with an oligotrophic basin. In June 2015, a rare large phytoplankton bloom, which is ~500 km long, 100 km wide and lasting more than 19 days, was captured in the northern SCS basin by satellite daily chlorophyll images. Water within the bloom area had a feature of low salinity and high temperature measured by an accidental-passing cruise. Meanwhile, satellite sea level anomaly images and drifter trajectory proved there was a cyclonic eddy nearby. No typhoon and heavy rain happened in this period, so we believed the bloom was triggered by the injection of nutrient-rich Pearl River plume driven by eddy. This is the first report on eddy-entrained Pearl River plume into the SCS, which would raise a new view on irregular transportation of nutrient and carbon and its related biogeochemical influence on the oligotrophic ocean.

  9. Cenozoic tectonic evolution and petroleum exploration in Perl River Mouth basin, South China Sea

    SciTech Connect

    Chi Yukun; Xu Shice )

    1990-06-01

    The Pearl River Mouth basin is a large Cenozoic continental margin basin that is rich in hydrocarbon potential. Fluvial-lake sequences were deposited before Oligocene, but all were covered by Miocene marine clastic and carbonate rocks. Both paleo-Pearl River delta system and reef/bank carbonate system were widely developed. At the early stage of the evolution, two subsidence belts and one uplift between them distributed in NE regional direction; grabens occurred in the north belt and depressions in the south belt. Tectonic movement was stronger in the east than the west. The main production zones have been drilled both in Miocene sandstone and carbonate rocks. As the exploration activities are developing, the basin will be one of the most significant China offshore oil production areas.

  10. Effects of climate change on water resources in Tarim River Basin, Northwest China.

    PubMed

    Chen, Ya-ning; Li, Wei-hong; Xu, Chang-chun; Hao, Xin-ming

    2007-01-01

    Based on hydrology, temperature, and precipitation data from the past 50 years, the effects of climate change on water resources in Tarim River Basin in Northwest China were investigated. The long-term trends of the hydrological time series were detected using both parametric and nonparametric techniques. The results showed that the increasing tendency of the temperature has a 5% level of significance, and the temperature increased by nearly 1 degree C over the past 50 years. The precipitation showed a significant increase in the 1980s and 1990s, and the average annual precipitation exhibited an increasing trend with a magnitude of 6.8 mm per decade. A step change occurred in both the temperature and precipitation time series around 1986. The streamflow from the headwater of the Tarim River exhibited a significant increase during the last 20 years. The increase in temperature, precipitation, and streamflow may be attributed to global climate change.

  11. Hydrogeochemical indicators of groundwater flow systems in the Yangwu River alluvial fan, Xinzhou Basin, Shanxi, China.

    PubMed

    Han, Dongmei; Liang, Xing; Jin, Menggui; Currell, Matthew J; Han, Ying; Song, Xianfang

    2009-08-01

    Based on analysis of groundwater hydrochemical and isotopic indicators, this article aims to identify the groundwater flow systems in the Yangwu River alluvial fan, in the Xinzhou Basin, China. Groundwater delta(2)H and delta(18)O values indicate that the origin of groundwater is mainly from precipitation, with local evaporative influence. d-excess values lower than 10% in most groundwaters suggest a cold climate during recharge in the area. Major ion chemistry, including rCa/rMg and rNa/rCl ratios, show that groundwater salinization is probably dominated by water-rock interaction (e.g., silicate mineral weathering, dissolution of calcite and dolomite and cation exchange) in the Yangwu River alluvial fan, and locally by intensive evapotranspiration in the Hutuo River valley. Cl and Sr concentrations follow an increasing trend in shallow groundwater affected by evaporation, and a decreasing trend in deep groundwater. (87)Sr/(86)Sr ratios reflect the variety of lithologies encountered during throughflow. The groundwater flow systems (GFS) of the Yangwu River alluvial fan include local and intermediate flow systems. Hydrogeochemical modeling results, simulated using PHREEQC, reveal water-rock interaction processes along different flow paths. This modeling method is more effective for characterizing flow paths in the intermediate system than in the local system. Artificial exploitation on groundwater in the alluvial fan enhances mixing between different groundwater flow systems. PMID:19548025

  12. Migration patterns of Neolithic settlements on the abandoned Yellow and Yangtze River deltas of China

    NASA Astrophysics Data System (ADS)

    Chen, Zhongyuan; Zong, Yongqiang; Wang, Zhanghua; Wang, Hui; Chen, Jing

    2008-09-01

    Archaeological records of the Neolithic settlements on the eastern China coast between 35°N and 30°N, an area covering the abandoned Yellow River and the Yangtze River delta plains, reveal that Neolithic people moved from the Yellow River basin onto the northern coast for fishing, hunting and dry-land agriculture ~ 7000 yr ago. Marine transgression interrupted their activities on the low-lying (2-5 m in elevation) coastal wetlands between 6000 and 5000 yr ago, after which they reclaimed their land near the river mouths. Their migration routes on the southern Yangtze delta plain indicate another scenario: early Neolithic communities moved onto the plain for wet-rice cultivation. Despite relative sea-level rise from 7000 to 4000 yr ago, a large number of settlements were established on the lowlands between the eastern Chenier Ridges and the western Taihu Lake depression. The Chenier Ridges, with ~ 1.0 m higher topography than the adjacent coastal area, played a role in sheltering the Neolithic people. Subsequently, settlements waned considerably, possibly due to further marine inundation combined with cold climate. The present study shows that migration patterns of the Neolithic settlements are closely associated with a gradually rising sea level between 7000 and 4000 yr ago.

  13. Magnitude, frequency and timing of floods in the Tarim River basin, China: Changes, causes and implications

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Sun, Peng; Chen, Xiaohong; Kong, Dongdong

    2016-04-01

    The flood magnitude, frequency and timing were analyzed using daily flow data for a period of 1950-2007 from 8 stations in the Tarim River basin, a typical arid inland river basin in China. The causes for flood occurrences were investigated using daily meteorological data. Results indicated that precipitation and temperature were increasing persistently since the 1980s and significant increases in precipitation and temperature were observed after the 1990s. As a result, floods amplified at annual and seasonal time scales in most tributary basins after the 1980s. The floods in the basin are mainly attributed to rainstorms and melting of glaciers and snowpack, and rainstorm-induced floods and temperature-induced floods were dominant in the basin. Extreme floods, such as the three largest recorded floods and floods with return periods > 10 years occurred mainly after the 1990s, with significant increase in flood-induced crop and livestock losses. It was found that heavy floods in many tributary basins often occurred about the same time. The Tarim River basin is a typical arid inland river basin in a high altitude zone and amplifying floods in recent decades, particularly after 1990s, is arousing considerable concern for mitigation of flood hazards. Results of this study shed light on hydrological response of arid regions to warming climate at higher latitudes in the northern hemisphere.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27166177

  15. 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

    2016-01-01

    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. PMID:27166177

  16. Hydrogeochemical indicators of groundwater flow systems in the Yangwu River alluvial fan, Xinzhou Basin, Shanxi, China.

    PubMed

    Han, Dongmei; Liang, Xing; Jin, Menggui; Currell, Matthew J; Han, Ying; Song, Xianfang

    2009-08-01

    Based on analysis of groundwater hydrochemical and isotopic indicators, this article aims to identify the groundwater flow systems in the Yangwu River alluvial fan, in the Xinzhou Basin, China. Groundwater delta(2)H and delta(18)O values indicate that the origin of groundwater is mainly from precipitation, with local evaporative influence. d-excess values lower than 10% in most groundwaters suggest a cold climate during recharge in the area. Major ion chemistry, including rCa/rMg and rNa/rCl ratios, show that groundwater salinization is probably dominated by water-rock interaction (e.g., silicate mineral weathering, dissolution of calcite and dolomite and cation exchange) in the Yangwu River alluvial fan, and locally by intensive evapotranspiration in the Hutuo River valley. Cl and Sr concentrations follow an increasing trend in shallow groundwater affected by evaporation, and a decreasing trend in deep groundwater. (87)Sr/(86)Sr ratios reflect the variety of lithologies encountered during throughflow. The groundwater flow systems (GFS) of the Yangwu River alluvial fan include local and intermediate flow systems. Hydrogeochemical modeling results, simulated using PHREEQC, reveal water-rock interaction processes along different flow paths. This modeling method is more effective for characterizing flow paths in the intermediate system than in the local system. Artificial exploitation on groundwater in the alluvial fan enhances mixing between different groundwater flow systems.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  19. 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.

  20. 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. PMID:27447226

  1. 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.

  2. Land subsidence at aquaculture facilities in the Yellow River delta, China

    NASA Astrophysics Data System (ADS)

    Higgins, Stephanie; Overeem, Irina; Tanaka, Akiko; Syvitski, James P. M.

    2013-08-01

    Differential Interferometric Synthetic Aperture Radar is applied to the coast of the Yellow River delta (YRD) in China. Like many deltas, the coastline of the YRD is dominated by aquaculture. Advanced Land Observation Satellite Phased Array L-Band Synthetic Aperture Radar (SAR) and Envisat Advanced SAR data acquired between 2007 and 2011 show that subsidence rates are as high as 250 mm/y at aquaculture facilities, likely due to groundwater pumping. These rates exceed local and global average sea level rise by nearly 2 orders of magnitude and suggest that subsidence and associated relative sea level rise may present a significant hazard for Asian megadeltas.

  3. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China.

    PubMed

    Liu, Ying; Chen, Ling; Jianfu, Zhao; Qinghui, Huang; Zhiliang, Zhu; Hongwen, Gao

    2008-07-01

    Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration of the Suzhou River was close to the average concentration of the Huangpu River. PAHs source analysis suggested that, in the Yangtze Estuary, PAHs at locations far away from cities were mainly from petrogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. In the Huangpu and Suzhou Rivers, pyrogenic input outweighed other sources. The pyrogenic PAHs in the upper reaches of the Huangpu River were mainly from the incomplete combustion of grass, wood and coal, and those in the middle and lower reaches were from vehicle and vessel exhaust. PMID:18045759

  4. Apcocynum Pictum and Sustainable Agriculture Along the Tarim River In Arid Northwest, China

    NASA Astrophysics Data System (ADS)

    Aihemaitijiang, R.

    2014-12-01

    Water scarcity and population increase have been a major limiting factor in oasis development along the Tarim River in Xinjiang, Northwest China which has very continental and dry climate, and all the agriculture and livelihoods depend on glacier melt water from Tarim River. Due to vast land reclamation along the Tarim River to grow cotton, native plant species are facing a severe competition for water, which is essential for their survival. Decreasing river runoff and inefficient water use practices by agriculture and industry has exacerbated already serious situation even worse. In addition, a large influx of migrant famers from Eastern China is being settled in this region to cultivate new agricultural lands that consumed even more water. Under those conditions, the natural riparian vegetation and the irrigation agriculture, especially along the lower reaches, suffers water shortage leading the degradation and economic losses, respectively. Along with the enlargement of irrigation area and periods of water shortage, soil salinization has become a major concern for farmers in the area. Alternative cash crops are much needed to reduce water use, so both native vegetation and human demand for water would be fulfilled. We hypothesized Apocynum Pictum, perennial herb species with multiple uses as potential substitute. Multidisciplinary approach is being used in this study to investigate three related issues to offer a basis for Apocynum's role in sustainable agriculture, such as Biomass production of Apocynum; Water budget of Apocynum; and Economic utilization of Apocynum. A.Pictum is perennial plant distributed in Central Asia and China, which its roots are perennial, while the stems die every year. Thus, A.pictum grow under the arid climate of Central Asia and provide utilization options without irrigation. We initially estimate water requirement for this plant is much less than cotton. In order to validate our hypothesis, we have measured water consumption of the

  5. [Characteristics and adaptation of seasonal drought in southern China under the background of global climate change. IV. Spatiotemporal characteristics of drought for maize based on crop water deficit index].

    PubMed

    Sui, Yue; Huang, Wan-Hua; Yang, Xiao-Guang; Li, Mao-Song

    2013-09-01

    Based on the 1959-2008 meteorological data from 249 meteorological stations in southern China, and by using crop water deficit index (CWDI) as the agricultural drought index, this paper calculated the drought frequency and drought stations ratio in this region, and analyzed the spatiotemporal distribution characteristics of drought for spring maize and summer maize during their growth periods. As for the spatial pattern of drought frequency, the drought for spring maize was more severe in the north of Huaihe River, northern Yunnan, and southern South China, but was lighter in the other regions. Except that the drought for summer maize at its late developmental stage was more severe in the middle-lower reaches of Yangtze River, northern South China, and eastern Southwest China, the drought for summer maize at its other developmental stages within southern China was lighter. As for the variation trend of drought intensity and drought area, the drought intensity of spring maize from its seven-leaf stage to jointing stage in the middle-lower reaches of Yangtze River increased obviously, while the drought intensity and drought area of the spring maize from its late spinning stage to milky maturity stage presented a decreasing trend. The drought of summer maize from its late jointing stage to tasseling stage and from late spinning stage to milky maturity stage all showed a decreasing trend. In Southwest China, the drought intensity and drought area for spring maize and summer maize had no clear trend. From the viewpoint of the inter-annual and decadal variability of drought intensity and drought area, there was a larger variation for the summer maize in the middle-lower reaches of Yangtze River, but less difference in Southwest China.

  6. Quaternary evolution of the rivers of northeast Hainan Island, China: Tracking the history of avulsion from mineralogy and geochemistry of river and delta sands

    NASA Astrophysics Data System (ADS)

    Pe-Piper, Georgia; Piper, David J. W.; Wang, Ying; Zhang, Yongzhan; Trottier, Corwin; Ge, Chendong; Yin, Yong

    2016-03-01

    The mineralogy and geochemistry of sands were investigated in the Nandu and Wanquan rivers, Hainan Island, China, to determine the history of avulsion in the lower reaches of the Nandu River. The study also provided the opportunity to assess the utility of geochemical analysis of sands as a provenance tool. Much of the heavy mineral fraction in the rivers consists of subangular Fe-Ti oxide and Fe-(hydr)oxide minerals, and less stable minerals such as amphibole, epidote, and andalusite, whereas rounded resistant ilmenite, rutile, tourmaline and zircon predominate on the deltaic coast. Mineral assemblage and chemical composition of individual samples are related to specific source areas and river tributaries. The results demonstrate northwestwards flow of the Nandu River during the mid-Holocene and earlier avulsion of the river to the northeast coast, probably during a Late Pleistocene marine highstand. Minor basement tilting, producing little relief, was sufficient to divert the lower reaches of rivers, and this effect was enhanced where basalt flows dammed former river courses. Bulk sample REE geochemistry is largely controlled by the relative abundance of monazite, allanite, titanite, zircon and epidote, derived principally from granites. Detrital geochemistry alone shows too much variability to interpret provenance. However, a smaller number of heavy mineral analyses provide an understanding of the mineralogical origins of geochemical variation, thus enabling interpretations of provenance.

  7. Towards a climate impact assessment of the Tarim River, NW China: integrated hydrological modelling using SWIM

    NASA Astrophysics Data System (ADS)

    Wortmann, Michel

    2014-05-01

    The Tarim River is the principle water source of the Xinjiang Uyghur Autonomous Region, NW China and the country's largest endorheic river, terminating in the Taklamakan desert. The vast majority of discharge is generated in the glaciated mountain ranges to the north (Tian Shan), south (Kunlun Shan/Tibetan Plateau) and west (Pamir Mountains) of the Taklamakan desert. The main water user is the intensive irrigation agriculture for mostly cotton and fruit production in linear river oases of the middle and lower reaches as well as a population of 10 Mil. people. Over the past 40 years, an increase in river discharge was reported, assumed to be caused by enhanced glacier melt due to a warming climate. Rapid population growth and economic development have led to a significant expansion of area under irrigation, resulting in water shortages for downstream users and the floodplain vegetation. Water resource planning and management of the Tarim require integrated assessment tools to examine changes under future climate change, land use and irrigation scenarios. The development of such tools, however, is challenged by sparse climate and discharge data as well as available data on water abstractions and diversions. The semi-distributed, process-based hydrological model SWIM (Soil and Water Integrated Model) was implemented for the headwater and middle reaches that generate over 90% of discharge, including the Aksu, Hotan and Yarkant rivers. It includes the representation of snow and glacier melt as well as irrigation abstractions. Once calibrated and validated to river discharge, the model is used to analyse future climate scenarios provided by one physically-based and one statistical regional climate model (RCM). Preliminary results of the model calibration and validation indicate that SWIM is able simulate river discharge adequately, despite poor data conditions. Snow and glacier melt account for the largest share in river discharge. The modelling results will devise

  8. Evaporation variability under climate warming in five reanalyses and its association with pan evaporation over China

    NASA Astrophysics Data System (ADS)

    Su, Tao; Feng, Taichen; Feng, Guolin

    2015-08-01

    With the motivation to identify actual evapotranspiration (AE) variability under climate warming over China, an assessment is made from five sets of reanalysis data sets [National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR), NCEP-Department of Energy (NCEP-DOE), Modern-Era Retrospective Analysis for Research and Applications (MERRA), Interim Reanalysis, and Japanese 55-year Reanalysis (JRA-55)]. Based on comparison with AE estimates calculated using the Budyko equation, all five reanalysis data sets reasonably reproduce the spatial patterns of AE over China, with a clearly southeast-northwest gradient. Overall, JRA-55 (NCEP-DOE) gives the lowest (highest) reanalysis evaporation (RE) values. From 1979 to 2013, dominant modes of RE among five reanalyses are extracted using multivariate empirical orthogonal function analysis. Accordingly, the interdecadal variation of RE is likely driven by the change of temperature, and the interannual variation is constrained by the water supply conditions. Under climate warming, RE increase in the Northwest China, Yangtze-Huaihe river basin, and South China, while they decrease in Qinghai-Tibet Plateau, and northern and Northeast China. Moreover, the relationship between RE and pan evaporation (PE) are comprehensively evaluated in space-time. Negative correlations are generally confirmed in nonhumid environments, while positive correlations exist in the humid regions. Our analysis supports the interpretation that the relationship between PE and AE was complementary with water control and proportional with energy control. In view of data availability, important differences in spatial variability and the amount of RE can be found in Northwest China, the Qinghai-Tibet Plateau, and the Yangtze River Basin. Generally speaking, NCEP-NCAR and MERRA have substantial problems on describing the long-term change of RE; however, there are some inaccuracies in the JRA-55 estimates when focusing on

  9. Monitoring of organochlorine pesticides using PFU systems in Yunnan lakes and rivers, China.

    PubMed

    Yang, Jun; Zhang, Wenjing; Shen, Yunfen; Feng, Weisong; Wang, Xinhua

    2007-01-01

    Polyurethane foam unit (PFU) systems were collected from 11 lakes and three rivers in the Yunnan Plateau, China and, the PFU extrusion liquids were analyzed for organochlorine pesticides (OCPs) by gas chromatography with electron capture detection (GC-ECD). The concentrations of pp'-DDE, HCB and HCHs were undetectable to 1.86 microgl-1 (mean 0.27 microgl-1), undetectable to 0.72 microgl-1 (mean 0.11 microgl-1), and 0.24-21.95 microgl-1 (mean 7.39 microgl-1) respectively in lakes; and those in rivers were undetectable to 0.23 microgl-1 (mean 0.08 microgl-1), 0.68-2.93 microgl-1 (mean 1.70 microgl-1), and 2.71-37.56 microgl-1 (mean 17.01 microgl-1) respectively. Notably, some residue levels of OCPs exceeded the US National Recommended Water Quality Criteria, implying Yunnan has levels of OCPs potentially harmful to human health. Further, the contamination by OCPs showed an obvious spatial distribution pattern. Amongst the lakes, Dianchi, Xingyun, Lugu and Yangzonghai had the highest OCP levels dominated by beta-HCH, whereas among rivers, Nujiang and Lancang Rivers had the highest contents of OCPs dominated by alpha-HCH. This demonstrates that HCHs are the predominant contaminants and some point sources of HCHs may still exist in Yunnan. The pollution levels in Yunnan were compared with other studies, suggesting the PFU method is suitable for long-term on-line monitoring of trace OCPs in aquatic ecosystems. Therefore, continuous studies monitoring OCPs in lakes and rivers are needed to further understand the future trend of contamination.

  10. Heavy-mineral analysis and provenance of Yellow River sediments around the China Loess Plateau

    NASA Astrophysics Data System (ADS)

    Pan, Baotian; Pang, Hongli; Gao, Hongshan; Garzanti, Eduardo; Zou, Yu; Liu, Xiaopeng; Li, Fuqiang; Jia, Yunxia

    2016-09-01

    In its upper-middle reaches the Yellow River has high sand contents after traversing through large areas of desert and the China Loess Plateau. Understanding riverbed sediment composition in the channel is critical for the interpretation of the potential provenance, aeolian sand transport and the linkage between the Loess Plateau and the Yellow River. To address these issues, we collected 52 samples from the modern riverbed, proximal deserts, and major tributaries and used analyses of grain size, grain morphology, and heavy-mineral compositions, to establish the spatial distribution and characteristics of source regions and riverbed sediments. The heavy-mineral assemblages demonstrate significant variations for the different sections of the Yellow River. The riverbed samples from the upper reach are dominated by opaque minerals (limonite and magnetite), amphibole and epidote, with minor zircon, tourmaline and rutile. Riverbed sediments from the middle reach are garnet-rich, reflecting the widespread distribution of Mesozoic sandstones. This variability closely reflects the source regions. Our data show that seasonal tributaries (the "Ten Great Gullies") carrying detritus from the Ordos Plateau may account for the localized high garnet concentrations in the Inner Mongolia section of the upper reach. Scanning electron microscope (SEM) imaging of quartz grains show that the river sediments are characterized by composite microtextures acquired in both fluvial and eolian environments of the Hedong, Ulan Buh and Kubuq Deserts. The mineralogical composition in the upper reach (Lanzhou-Yinchuan) is similar to that of sediments in the Loess Plateau and Northeast Tibet Plateau (Western Lanzhou). However, the composition differs markedly from that in the Inner Mongolia section of the upper and middle reaches. This variation indicates that in the upper reach the Northeast Tibet Plateau contributes significant volumes of sediment to the Yellow River and Loess Plateau, but

  11. 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.

  12. 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

  13. Carbon dioxide emission from surface water in cascade reservoirs-river system on the Maotiao River, southwest of China

    NASA Astrophysics Data System (ADS)

    Wang, Fushun; Wang, Baoli; Liu, Cong-Qiang; Wang, Yuchun; Guan, Jin; Liu, Xiaolong; Yu, Yuanxiu

    2011-07-01

    Recently, controversies about whether hydropower is still a clean energy have been arisen up with the studies about high CO 2 emission flux from hydroelectric reservoirs in boreal and tropical regions. In this study, four subtropical reservoirs and their related reaches, draining on karstic area in southwest of China, were investigated to understand their CO 2 emission, with monthly sampling strategy from July 2007 to June 2008. pCO 2 values in the surface water of these reservoirs ranged from 38 to 3300 μ atm, indicating that reservoir surface could be not only source but also sink to atmosphere CO 2 in different seasons. In Hongfeng reservoir, the flux of CO 2 from surface water varied from -9 to 70 mmol m -2 d -2 with an average of 15 mmol m -2 d -2, and in Baihua reservoir, it had a range from -8 to 77 mmol m -2 d -2 with an average of 24 mmol m -2 d -2. Hongyan reservoir had similar average flux of CO 2 to Baihua reservoir. Xiuwen had the highest average flux of CO 2 with a value of 47 mmol m -2 d -2 among the studied reservoirs. Downstream the dams discharged by hydropower generation from these reservoirs generally had quite high flux of CO 2, with an average of 489 ± 297 mmol m -2 d -2, which is close to those from tropical rivers. This means that water releasing from these reservoirs would be an important way for CO 2 emission into atmosphere. The results showed that dam construction has significant impacts on the river water chemistry, with abrupt changes in pCO 2, DO, T, pH and SIc in surface water and their outlets. In addition, with the development of thermal gradient in warm seasons, water chemistry along the water column of reservoirs also showed seasonal variations, except in Xiuwen reservoir which only has daily storage capacity.

  14. 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. PMID:25847753

  15. 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.

  16. 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.

  17. 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. PMID:25907628

  18. 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.

  19. [Spatiotemporal pattern of carbon sources and sinks in Yangtze River Delta region, China].

    PubMed

    Yi, Bai-lu; Han, Ji; Zhou, Xiang; Yang, Fang; Meng, Xing; Cao, Wu-xing; Huang, Lu-xia; Xiang, Wei-ning

    2015-04-01

    Yangtze River Delta region is the world's sixth and China's largest urban agglomeration. Its rapid and massive urbanization has also caused a series of ecological and environmental impacts. This paper accounted the inventory of carbon sources and sinks in Yangtze River Delta region during 1995-2010 and analyzed their spatiotemporal patterns. It was found that the carbon sinks increased by 9.43 million tons from 1995 to 2010, in which forest ecosystem net production in Zhejiang Province was the largest contributor. The "grain for green" policy implemented since 2003 in China played a significant role in increasing the forest area and the carbon sinks. The carbon sources increased by 327 million tons, and energy consumption and industrial processes based emissions accounted for 96% of total carbon sources in 2010. Due to the large share of manufacturing and heavy industries in economy and their dependence on the high carbon intensity energy, either the amount or the growth speed of carbon emissions in Jiangsu Province was the top one in the whole region. Moreover, because the growth speed of net carbon emissions that occurred upon the built-up land was much faster than the sprawl speed of urban built-up land, the net carbon emission intensity kept increasing in the whole region, in which Jiangsu Province demonstrated the fastest increase.

  20. [Spatiotemporal pattern of carbon sources and sinks in Yangtze River Delta region, China].

    PubMed

    Yi, Bai-lu; Han, Ji; Zhou, Xiang; Yang, Fang; Meng, Xing; Cao, Wu-xing; Huang, Lu-xia; Xiang, Wei-ning

    2015-04-01

    Yangtze River Delta region is the world's sixth and China's largest urban agglomeration. Its rapid and massive urbanization has also caused a series of ecological and environmental impacts. This paper accounted the inventory of carbon sources and sinks in Yangtze River Delta region during 1995-2010 and analyzed their spatiotemporal patterns. It was found that the carbon sinks increased by 9.43 million tons from 1995 to 2010, in which forest ecosystem net production in Zhejiang Province was the largest contributor. The "grain for green" policy implemented since 2003 in China played a significant role in increasing the forest area and the carbon sinks. The carbon sources increased by 327 million tons, and energy consumption and industrial processes based emissions accounted for 96% of total carbon sources in 2010. Due to the large share of manufacturing and heavy industries in economy and their dependence on the high carbon intensity energy, either the amount or the growth speed of carbon emissions in Jiangsu Province was the top one in the whole region. Moreover, because the growth speed of net carbon emissions that occurred upon the built-up land was much faster than the sprawl speed of urban built-up land, the net carbon emission intensity kept increasing in the whole region, in which Jiangsu Province demonstrated the fastest increase. PMID:26259436

  1. 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

  2. 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

  3. Polybrominated diphenyl ethers (PBDEs) in aquatic biota from the lower reach of the Yangtze River, East China.

    PubMed

    Gao, Zishen; Xu, Jie; Xian, Qiming; Feng, Jianfang; Chen, Xiaohui; Yu, Hongxia

    2009-05-01

    Sixteen species of aquatic biota from the lower reach of the Yangtze River including fishes, crabs and shrimps were collected and analyzed for 13 polybrominated diphenyl ethers (PBDEs) congeners. All the PBDEs congeners except BDE-17 were detectable in the samples indicating that the aquatic biota from the lower reach of the Yangtze River are widely exposed to these pollutants. The Sigma(12)PBDEs ranged from 3.52 to 603.69 ng/g lipid (0.032-62.69 ng/g wet wt), with a mean of 44.04 ng/g lipid (2.69 ng/g wet wt). The PBDEs levels in the Yangtze River aquatic biota were low to average compared to PBDEs levels in aquatic biota around the world. The predominant congeners were BDE-47, BDE-28, BDE-154, BDE-100 and BDE-153. The proportion of BDE-28 seemed to be relatively high which was different from the result in other studies around the world but consistent with the results in China. The congener pattern of the sample was similar to the pattern in the sediment from the Yangtze River which implies that sediment may be an important PBDEs source for aquatic biota in the lower reach of the Yangtze River. Although the PBDEs levels in aquatic biota this area is comparable to or even lower than that in other areas in China, such as the Pearl River Delta and the Laizhou Bay, the increasing textiles, chemical and electronic industry may bring more and more PBDEs contamination to the Yangtze River Delta. The fact that PBDEs were detectable in all the biota samples from the lower reach of the Yangtze River should be an alarm for increasing risk in the Yangtze River Delta, East China.

  4. 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

  5. Identification and characterization of microbial agents in a bloom of floating microorganisms in the Hailang River, China in 2006

    NASA Astrophysics Data System (ADS)

    Wu, Weili; Wang, Jinglin; Liu, Licheng; Jiang, Jun; Chen, Yan; Hu, Tao; Chen, Weijun

    2010-07-01

    In February 2006, a large amount of unknown floating microorganisms appeared in the Hailang River (HR) in the City of Hailin, Heilongjiang Province, China. The microorganisms caused the river water fouling and threatened the clean water supply of the city. To identify the unknown floating organisms, morphological and histological inspection, PCR, cloning and sequence analysis were conducted. The results revealed that the unknown floating organisms in the river were a novel species that likely belonged to oomycetes in Saprolegniales. The organisms were named Saprolegnia sp. HL0602.

  6. 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. PMID:24865385

  7. 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.

  8. China's Yangtze delta: Geochemical fingerprints reflecting river connection to the sea

    NASA Astrophysics Data System (ADS)

    Gu, Jiawei; Chen, Jing; Sun, Qianli; Wang, Zhanghua; Wei, Zixin; Chen, Zhongyuan

    2014-12-01

    This study investigates sediment source to sink relating the connection of the Yangtze River to the sea. A sediment borehole (PD) on the river coast, penetrating thick Quaternary sediments and thin sediments of late Pliocene age down to the bedrock, recorded a change in sediment provenance through time. Geochemical elements and magneto-stratigraphy help identify five zones. Zone I (the late Pliocene-the Early Pleistocene), characterized by Pb, Th, U, Ba, La, Ce, Nd, Hf, Y, Zr, Nb and Mn, indicates a local sediment provenance. This means that the study area was a localized sub-basin. Zone II (the Early Pleistocene-the mid-stage of the Early Pleistocene), with remarkable high Fe, K, As and Rb implies a new sediment provenance joining the sub-basin from the middle Yangtze reach after the opening of the Zhenjiang Gorge. Zone III (the mid-stage of Early Pleistocene-the Middle Pleistocene), featured by Ti, V, Cr, Sr, Sc, Cu, Co, Ni, Mg, Ca, Na and P suggests a further extension of sediment provenance to the upper Yangtze basin, where a large block of the E'mei basalt and carbonate occurs. This suggests that the Three Gorges valley linking the upper and middle Yangtze reaches had developed by that time. Zones IV and V (the Middle Pleistocene-the Holocene) have shown their geochemical similarity to Zone III. Discrimination ratio f(Cr, Th), f(La) and f(K, La), a new approach developed for tracing sediment provenance, confirms a basin-wide sediment source through Zones III-V. These together witness a progressive extension of the sediment provenance towards the upper Yangtze basin, corresponding to the long-term tilting effect of the Cenozoic Topographic Reversal of the eastern China continent. The timing of the Yangtze River running through into the East China Sea appears at ca. 1.0-1.2 Ma (bottom of Zone III).

  9. 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

  10. 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.

  11. Characterization and distribution of polycyclic aromatic hydrocarbon in sediments of Haihe River, Tianjin, China.

    PubMed

    Jiang, Bin; Zheng, Hai-Long; Huang, Guo-Qiang; Ding, Hui; Li, Xin-Gang; Suo, Hong-Tu; Li, Rui

    2007-01-01

    In this study sediment samples were collected from 13 sites of Haihe River in Tianjin City, China, sixteen of priority polycyclic aromatic hydrocarbons (PAHs) listed in USEPA were analyzed by means of GC-MS. The total concentrations of PAH ranged from 774.81 to 255371.91 ng/g dw, and two to four rings of PAHs were dominant in sediment samples. Molecular ratios, such as phenanthrene/anthracene, fluoranthene/pyrene and low-molecular-weight PAH /high-molecular-weight PAH, were used to study the possible sources of pollution. It indicated a mixed pattern of parolytic and petrogenic inputs of PAHs in sediments in Haihe River. The petrogenic PAHs may be mainly derived from the leakage of refined products, e.g., gasoline, diesel fuel and fuel oil vehicle traffics or gas stations from urban area. The pyrolytic PAHs might be from the discharge of industrial wastewater and the emission of atmospheric particles from petrochemical factories. In addition, the levels of PAHs in the urban and industrial areas are far beyond the values reported from other rivers and marine systems reported. This situation may be due to polluted discharging from some petrochemical industrial manufactories and worse traffic conditions in Tianjin. PMID:17918592

  12. 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. PMID:27380073

  13. [Regionalization of the freshwater eco-regions in the Haihe River Basin of China].

    PubMed

    Sun, Ran-Hao; Ji, Yu-He; Shang, Lin-Yuan; Zhang, Hai-Ping; Chen, Li-Ding

    2013-02-01

    There is a growing concern about the ecological conditions in the Haihe River which have been profoundly impacted by the growing human population and intensifying development over the past several decades. By identifying the spatial characteristics of terrestrial and fluvial landscapes, we propose the guidelines and criterions for regionalizing the freshwater ecosystems in the Haihe River basin. The first-level and second-level zones reflect the spatial patterns of the natural backgrounds which could impact the surface water quantity and quality. The 6 first-level zones are regionalized according to topographic characteristics, runoff depth, annual precipitation and evaporation. They represent the spatial pattern of water resource quantity. The 16 second-level zones are regionalized according to the vegetation and soil types overlaid by the first-level zones. They represent the spatial patterns of eco-hydrological processes and water purifying functions of terrestrial landscapes. Finally, the eco-regions are evaluated by the field survey data including water quality, aquatic vegetation and zoobenthos communities. This study could potentially be used to guide the decision-making process for the management of water resources and local ecological projects in the Haihe River basin. The methods formulated in this research can possibly provide important references for other watersheds in China. PMID:23668116

  14. Groundwater evolution and recharge determination of the Quaternary aquifer in the Shule River basin, Northwest China

    NASA Astrophysics Data System (ADS)

    He, Jianhua; Ma, Jinzhu; Zhao, Wei; Sun, Shuang

    2015-12-01

    Groundwater recharge and evolution in the Shule River basin, Northwest China, was investigated by a combination of hydrogeochemical tracers, stable isotopes, and radiocarbon methods. Results showed the general chemistry of the groundwater is of SO4 2- type. Water-rock reactions of halite, Glauber's salt, gypsum and celestite, and reverse ionic exchange dictated the groundwater chemistry evolution, increasing concentrations of Cl-, Na+, SO4 2-, Ca2+, Mg2+ and Sr2+ in the groundwater. The δ18O and δ2H values of groundwater ranged from -10.8 to -7.7 and -74.4 to -53.1 ‰, respectively. Modern groundwater was identified in the proluvial fan and the shallow aquifer of the fine soil plain, likely as a result of direct infiltration of rivers and irrigation returns. Deep groundwater was depleted in heavy isotopes with 14C ages ranging from 3,000 to 26,000 years, suggesting palaeowater that was recharged during the late Pleistocene and middle Holocene epochs under a cold climate. These results have important implications for groundwater management in the Shule River basin, since large amounts of groundwater are effectively being mined and a water-use strategy is urgently needed.

  15. Measurement comparison of gas phase pollutants during field campaign in Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Shao, M.; Zeng, L.; Hu, M.; Zhang, Y.

    2005-12-01

    Pearl River delta, an economically developed region in Guangdong province China, has been suffering from serious ground-level ozone pollution. To understand the formation mechanisms of the photochemical smog in this area, a field measurement campaign involving 12 separate institutes, was performed from Oct. 1 to Nov. 4, 2004. Measurements of gas phase pollutants, performed by the different research groups using several different methods, were inter-compared. Ambient SO2, O3 and NO were measured by Peking University and Hong Kong Polytechnic University using the same methods: chemiluminescence for NOx, pulsed fluorescence for SO2, and UV photometric method for O3. VOC speciation was accomplished using canister sampling followed by GC-MS measurement by Peking University and on-line GC-FID technology by National Central University in Taiwan. Ambient concentrations of HONO, the photolysis of which is the most important source of OH radical in Pearl River delta, was measured by two wet chemical methods: one from Energy Research Foundation of the Netherlands and one developed in Peking University. Based on these inter-comparisons, the co-variation of O3, NO and VOCs at an urban site and one rural site in Pearl River delta and estimates of the relative contributions to OH production from photolysis of O3, HONO and HCHO will be presented.

  16. Distribution and loadings of polycyclic aromatic hydrocarbons in the Xijiang River in Guangdong, South China.

    PubMed

    Deng, Hongmei; Peng, Ping'an; Huang, Weilin; Song, Jianzhong

    2006-08-01

    The Xijiang River is the major tributary of the Pearl River, South China, and is the major source water system for more than 4.5 million of urban population and 28.7 million of rural population. We initiated a systematic study on detection and quantification of organic pollutants in both water and suspended particulate matter (SPM) for samples collected in a span of 12 months. Our results showed that total concentrations of 15 polycyclic aromatic hydrocarbons (PAHs) varied from 21.7 to 138 ng l(-1) in water and from 40.9 to 665 microg kg(-1) in SPM. The organic carbon normalized distribution coefficients (K(OC)) computed for the PAHs were correlated well with their octanol-water partition coefficient (K(OW)). The estimated annual loadings of Ant, BaA, and BghiP and the total PAHs in the Xijiang River were 1620, 330, 177 and 19,400 kg, respectively. Further analysis of the data showed that combustion may be the major source of PAHs and that direct leakage of petroleum products may be insignificant.

  17. 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. PMID:24561322

  18. 210Pb chronology and trace metal geochemistry in the intertidal sediment of Qinjiang River estuary, China

    NASA Astrophysics Data System (ADS)

    Xia, Peng; Meng, Xianwei; Feng, Aiping; Yin, Ping; Wang, Xiangqin; Zhang, Jun

    2012-06-01

    Historical records of metal inputs were studied by using a sediment core collected from a sand-rich mudflat in the Qinjiang River estuary, China. 210Pb chronology was used to reconstruct the fluxes of Hg, Cu, Pb, Zn, Cd, Cr and As to the core site during the last 86 years. Based on the constant initial concentration model, the sedimentation rates are 1.18 cm year-1 in the top 30 cm sandy layer and 0.92 cm year-1 in the muddy bottom layer. To compensate for grain-size and mineralogy effects on metal concentrations, aluminum was used as the normalizing element. The enrichment factors ( EF) indicate that the natural inputs had prevailed up to the early 1980s. After this period, the intensity of human activities has resulted in continual increasing trend of metals towards the surface. Recent sediment samples from the Qinjiang River estuary are found moderately enriched by Cd ( EF>1.5) and slightly enriched by other metals ( EF<1.5). Considering that the drainage area of the Qinjiang River is mostly agricultural land, the increased Cd may be due to the usage of fertilizers and pesticides in agricultural activities and the combustion of fossil fuels.

  19. 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.

  20. 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.

  1. The impacts of climate change on water resources in the Second Songhua River Basin, China

    NASA Astrophysics Data System (ADS)

    Yu, J. S.; Yao, X. L.; Sun, W. C.; Li, Z. J.

    2016-08-01

    The Northeast China Plain is one of the main grain growing regions in China. Due to the high latitude and black soil ecological system, the crop growth in there is vulnerable to climate change, which makes it important to evaluate the influences of climate change on water resources. In this study, the influences of climate change on water resources of a typical basin in northeast China, the Second Songhua River Basin were assessed using the SWAT model. Ensemble downscaled output from sixteen GCMs for A1B emission scenario in 2050s was adopted as the regional climate scenario and was used to drive SWAT model to predict hydrological changes. The prediction shows that mean evapotranspiration of whole basin increases in most time of a year. Stream flow of Fuyu gauging station downstream this basin exhibits a decrease trend from April to June, November and December, and increases in the remaining period of the year. It is indicated that water resources may not be sufficient in spring for irrigation and the possibility of flood in summer may increases, indicating countermeasures should be made to ensure agricultural water use and prevent possible damages of flood on crop.

  2. 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…

  3. 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...

  4. Fractional distribution and risk assessment of heavy metals in sediments collected from the Yellow River, China.

    PubMed

    Liu, Houqi; Liu, Guijian; Wang, Jie; Yuan, Zijiao; Da, Chunnian

    2016-06-01

    Bohai Sea is one of the most intensively exploited region in the world and its environment has been severely impacted by the extensive human activities. The Yellow River is the most important river which connects with the Bohai Sea. Therefore, this study focused on analyzing heavy metals (HMs) in 21 surface sediment samples collected from the Yellow River, China. Sequential extraction procedure (SEP), proposed by the Community Bureau of Reference (BCR), was applied in the present study to determine the concentration and fractionation characteristics of these HMs. The aim of this study was to investigate the spatial distribution, fractionation, risk assessment, and sources of HMs, including copper (Cu), zinc (Zn), lead (Pb), chromium (Cr), iron (Fe), manganese (Mn), and nickel (Ni). The results obtained from this research will play a significant role in understanding the migration, transformation, and accumulation of HMs for future research in study area. Results of fractionation revealed that most of the HMs in the study area mainly existed in residual fraction; however, Mn mostly existed in exchangeable fraction. A high percentage of reducible fractions was found for Cu and Pb. The mean contamination factor (Cf) values indicated that Pb was the highest. It was >1 and showed moderate contamination, followed by Cr, Cu, Mn, Ni, and Zn, had <1 and indicated low contamination. Among studied HMs Pb had higher enrichment factor (EF) as compared to others. Significant positive correlations within all studied HMs and principal component analysis (PCA) results indicated their common sources, however, Pb showed the different contamination sources. The total contents of HMs in sediment were compared with the threshold effect level (TEL) and probable effect level (PEL) sediment quality guideline (TEL/PEL-based SQGs) values for trace metals in sediment, as well as literature reported data for comparative purposes, which indicated that the selected river in present study is not

  5. 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

  6. Petroleum geology of the Zhu-1 depression, Pearl River Mouth Basin, People's Republic of China

    SciTech Connect

    Aguilera, C.L.; Huizinga, B.J.; Lomando, A.J. )

    1990-05-01

    The Pearl River Mouth basin, located in the South China Sea between Hainan Island and Taiwan has been the focus of an intense exploration effort during the l980s. In 1979 the international oil industry, acquired over 60,000 km of seismic, gravity, and magnetic data covering an area of approximately 240,000 km{sup 2}. Three major subbasins, Zhu-1, Zhu-2, and Zhu-3 were defined. Chevron in partnership with Texaco and AGIP (ACT group), concentrated their effort on the Zhu-1 depression which was interpreted to contain as much as 7,800 m of sedimentary section. This subbasin, bounded by the Wansha and Donsha massifs to the north and south, is the most inboard of the three depressions, thereby possibly prolonging anoxic lacustrine conditions prior to the Neogene marine incursion. Additionally, the Zhu- 1 depression should have directly received Miocene sediment potentially supplying the subbasin with high-quality reservoirs. Within the Zhu-1 depression, the ACT group focused in on Block 16/08, which covered the deepest part of the Zhu-1 depression. The block was awarded to the consortium in January 1983. Structuring within the block ranges from Paleogene tensional block faulting created during the early formation of the overall Pearl River Mouth basin to draping over basement highs and carbonate buildups during the Neogene. The Pearl River Mouth basin exhibits classic rift basin geometry with early nonmarine continental fluvial/lacustrine deposition (Zhuhai Formation) during the Oligocene and capped by a lower Miocene marine incursion (Zhu Jiang Formation). Integrated interpretations, exploration drilling, and constant refinement of the geological model led to the discovery of two oil fields, Huizhou/21-1 and Huizhou/26-1, both of which are currently under development and will represent the first commercial oil production from the entire Pearl River Mouth basin.

  7. Characteristics of nitrate in major rivers and aquifers of the Sanjiang Plain, China.

    PubMed

    Cao, Yingjie; Tang, Changyuan; Song, Xianfang; Liu, Changming; Zhang, Yinghua

    2012-10-26

    The characteristics of nitrate (NO(3)(-)) in major rivers and aquifers of the Sanjiang Plain, China were investigated by hydrogeochemical conditions, nitrogen isotope technique and CFCs trace. An overall understanding on the sources and fate of NO(3)(-) in the surface water and the groundwater was obtained. The NO(3)(-) concentrations in the surface water were low and no samples exceeds the WTO standards. However, 11.4% of the groundwater samples exceeded the WTO standards, indicating local NO(3)(-) pollution in rural areas. Redox condition analysis revealed that most of the surface water had oxic condition, while for the shallow groundwater (mean well depth smaller than 30 m), the redox condition began to change into anoxic zone, and the deep groundwater (mean well depth larger than 50 m) showed strong anoxic condition. The δ(15)N-NO(3) data indicated soil N and fertilizer contributed the major sources in the surface water, and NO(3)(-) in the groundwater mainly showed a manure origin. In the Songhua-Heilong River, dilution effect was dominating, while for the Wusuli River, it showed that mix with water contained excess of NO(3)(-) resulted in the NO(3)(-) concentration increased along the river. Additionally, the NO(3)(-) transportation in the groundwater was analyzed by groundwater ages derived from environmental tracer (CFCs) data. The relation between the groundwater ages and the NO(3)(-) concentrations showed that the young groundwater with the age less than 60 years had higher NO(3)(-) concentrations than the old groundwater over the age of 60 years because anthropogenic activities began to boom from 1950s in the Sanjiang Plain.

  8. Nutrient dynamics from the Changjiang (Yangtze River) estuary to the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Su Mei; Qi, Xiao Hong; Li, Xiaona; Ye, Hao Ran; Wu, Ying; Ren, Jing Ling; Zhang, Jing; Xu, Wei Yi

    2016-02-01

    Water and sediment samples were collected from the Changjiang (Yangtze River) estuary and the adjacent East China Sea during impoundment of the river at the Three Gorges Dam. The concentrations of dissolved inorganic and organic nutrients, and particulate inorganic phosphorus and particulate organic phosphorus in the water column (PIP and POP, respectively) and sediments (SIP and SOP, respectively) were analyzed. The nutrient dynamics in salt marshes associated with the Changjiang estuary were also considered. In addition, river water samples were collected bimonthly in the lower reaches of the Changjiang. The concentrations of dissolved inorganic nutrients, PIP and POP showed temporal and spatial variations, which decreased from the coast to offshore areas. The dissolved organic nitrogen and phosphorus (P) concentrations showed patchy distributions, but were consistent with the distribution of phytoplankton biomass. Phosphorus is the major limiting element for phytoplankton growth. Among the various P forms, particulate P represented 38-52% of total P. The PIP and POP concentrations showed clear seasonal variations corresponding to the occurrence of the levels of suspended particulate matter. The P accumulation rates showed a decreasing trend from the coast to offshore areas, and high P burial efficiencies were found; the latter were related to a low benthic PO43 - flux and high sediment accumulation rates. The potential bioavailable P was estimated to be 65-70% of total P, of which more than two-thirds was regenerated in the water column. The salt marsh in the Changjiang estuary plays an important ecological role in nutrient transport from the river to offshore areas, and increased P limitation.

  9. Patterns and structures of land use change in the Three Rivers Headwaters Region of China.

    PubMed

    Yang, Jingbiao; Wang, Yi Chen; Guo, Luo; Xue, Dayuan

    2015-01-01

    Located in Qinghai Province of China, the Three Rivers Headwaters Region is the source region of the Yangtze, Yellow and Lantsang Rivers, and plays an important role in biodiversity conservation and regulating water supply. Despite many efforts on land use change in Qinghai, knowledge of the spatial variation of land use change is still lacking. This study examines the patterns of land use change across various watersheds, prefectures and the temple surroundings. Remote sensing images of 1987, 1997 and 2007 were analyzed to derive land use distributions; patterns and structures of the landscape were then quantified with landscape metrics. The results illustrated that the Yangtze River headwater region had more diverse and more evenly distributed landscape, while the Lantsang and the Yellow headwater regions showed a decline in landscape diversity. Comparison of the land use patterns of four prefectures revealed that Yushu Prefecture experienced an increase in landscape diversity from 1987 to 2007 while the land use patches in Guoluo Prefecture exhibited more aggregated patterns than other prefectures. Analysis of the spatial variations of land use change in the temple surroundings illustrated that 19.7% and 35.9% of the temples in Guoluo and Yushu Prefectures, respectively, encountered land use change for their immediate areas within 2 km. Comparison of the surroundings of temples and human settlements found that land use change was not evenly distributed, and that greater land use change had occurred for the surroundings of human settlements. Such findings provided insights into the spatial variation of land use change in the Three Rivers Headwaters Region. PMID:25816147

  10. Patterns and structures of land use change in the Three Rivers Headwaters Region of China.

    PubMed

    Yang, Jingbiao; Wang, Yi Chen; Guo, Luo; Xue, Dayuan

    2015-01-01

    Located in Qinghai Province of China, the Three Rivers Headwaters Region is the source region of the Yangtze, Yellow and Lantsang Rivers, and plays an important role in biodiversity conservation and regulating water supply. Despite many efforts on land use change in Qinghai, knowledge of the spatial variation of land use change is still lacking. This study examines the patterns of land use change across various watersheds, prefectures and the temple surroundings. Remote sensing images of 1987, 1997 and 2007 were analyzed to derive land use distributions; patterns and structures of the landscape were then quantified with landscape metrics. The results illustrated that the Yangtze River headwater region had more diverse and more evenly distributed landscape, while the Lantsang and the Yellow headwater regions showed a decline in landscape diversity. Comparison of the land use patterns of four prefectures revealed that Yushu Prefecture experienced an increase in landscape diversity from 1987 to 2007 while the land use patches in Guoluo Prefecture exhibited more aggregated patterns than other prefectures. Analysis of the spatial variations of land use change in the temple surroundings illustrated that 19.7% and 35.9% of the temples in Guoluo and Yushu Prefectures, respectively, encountered land use change for their immediate areas within 2 km. Comparison of the surroundings of temples and human settlements found that land use change was not evenly distributed, and that greater land use change had occurred for the surroundings of human settlements. Such findings provided insights into the spatial variation of land use change in the Three Rivers Headwaters Region.

  11. Role of river bends for the formation and evolution of channel bedforms: Combined field studies and numerical modeling from the tidally influenced zones of the Yellow River, China, and Mississippi River, USA.

    NASA Astrophysics Data System (ADS)

    Ma, H.; Nittrouer, J. A.; Moodie, A.; Calson, B.; Parker, G.

    2015-12-01

    River bedforms represent the unstable interface between fluid flow and the granular channel bed, and these features play an important role for modifying flow resistance and sediment transport rates, and thus influencing river morphology. Although widely observed in natural rivers, bedforms are difficult to measure quantitatively and are rarely connected to other fluvial morphological processes. This study presents high-resolution channel bathymetric data from the tidally influenced, lowermost Yellow River, China, collected using a multibeam swath profiler. Repeat surveys were conducted over rising and flood discharge conditions, which is the first such kind of survey in Yellow River. The bathymetry data show that for all water discharges, a flat bed, devoid of a thalweg or dunes, persists within straight-reach segments near the bends of the Yellow River, despite the bed consisting of fine sand. Interestingly, in bend segments, the channel deepens, and linear dunes develop. Moreover, as the water discharge increases over time, the edge of dune field contained in the bend segments propagates into the adjacent upstream and downstream straight-reach segments. In contrasting case study, Nittrouer et al. (2008) reported persistent dune field in the straight reaches of the tidally influenced Mississippi River; however these dunes disappear in neighboring river bends. Based on the two cases of the Yellow and Mississippi Rivers, which have fundamentally different conditions of water-to-sediment discharge ratios, the threshold condition of bedform formation and stability are evaluated, and connected to local conditions of river bend morphology. This work improves the understanding of the co-evolution of bedforms and flow conditions in river bends, which are intertwined and important morphological processes that affect fluvial-deltaic sediment transport dynamics. In addition, the straight-bend structure is a basic element of river morphology, and so the results of this study

  12. 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

  13. 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

  14. 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.

  15. Distribution characteristics and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the Liao River drainage basin, northeast China.

    PubMed

    Hu, Jian; Liu, Congqiang; Zhang, Guoping; Zhang, Yanlin; Li, Siliang; Zhao, Zhiqi; Liu, Baojian; Guo, Qinjun

    2016-04-01

    The Liao River drainage basin, which is one of China's seven major rivers basins, is located in northeast China. This region is characterized by important industrial bases including steel factories and oil and chemical plants, all of which have the potential to contribute pollutants to the drainage basin. In this study, 16 polycyclic aromatic hydrocarbons (PAHs) in water and suspended particulate matter (SPM) in the major rivers of the Liao River drainage basin were identified and quantified by gas chromatography mass spectrometry (GC/MS). The total PAH concentrations ranged from 0.4 to 76.5 μg/g (dry weight) in SPM and 32.6 to 108 ng/L in surface water, respectively. Low-ring PAHs (including two- and three-ring PAHs) were dominant in all PAH samples, and the level of low-ring PAHs in surface water was higher than that in SPM. The proportion of two-ring PAHs was the highest, accounting for an average of 68.2 % of the total PAHs in surface water, while the level of three-ring PAHs was the highest in SPM, with an average of 66.3 %. When compared with other river systems, the concentrations of PAHs in the Liao River drainage basin were lower. Identification of the emission sources based on diagnostic ratios suggested petroleum and fossil fuel combustion were important contribution to PAHs in the study area.

  16. Water quality variation in the highly disturbed Huai River Basin, China from 1994 to 2005 by multi-statistical analyses.

    PubMed

    Zhai, Xiaoyan; Xia, Jun; Zhang, Yongyong

    2014-10-15

    Water quality deterioration is a prominent issue threatening water security throughout the world. Huai River Basin, as the sixth largest basin in China, is facing the most severe water pollution and high disturbance. Statistical detection of water quality trends and identification of human interferences are significant for sustainable water quality management. Three key water quality elements (ammonium nitrogen: NH3-N, permanganate index: CODMn and dissolved oxygen: DO) at 18 monitoring stations were selected to analyze their spatio-temporal variations in the highly disturbed Huai River Basin using seasonal Mann-Kendall test and Moran's I method. Relationship between surrounding water environment and anthropogenic activities (point source emission, land use) was investigated by regression analysis. The results indicated that water environment was significantly improved on the whole from 1994 to 2005. CODMn and NH3-N concentrations decreased at half of the stations, and DO concentration increased significantly at 39% (7/18) stations. The high pollution cluster centers for both NH3-N and CODMn were in the middle stream of Shaying River and Guo River in the 2000s. Water quality of Huai River Basin was mainly influenced by point source pollution emission, flows regulated by dams, water temperature and land use variations and so on. This study was expected to provide insights into water quality evolution and foundations for water quality management in Huai River Basin, and scientific references for the implementation of water pollution prevention in China.

  17. Assessing Local Communities’ Willingness to Pay for River Network Protection: A Contingent Valuation Study of Shanghai, China

    PubMed Central

    Shang, Zhaoyi; Che, Yue; Yang, Kai; Jiang, Yu

    2012-01-01

    River networks have experienced serious degradation because of rapid urbanization and population growth in developing countries such as China, and the protection of these networks requires the integration of evaluation with ecology and economics. In this study, a structured questionnaire survey of local residents in Shanghai (China) was conducted in urban and suburban areas. The study examined residents’ awareness of the value of the river network, sought their attitude toward the current status, and employed a logistic regression analysis based on the contingent valuation method (CVM) to calculate the total benefit and explain the socioeconomic factors influencing the residents’ willingness to pay (WTP). The results suggested that residents in Shanghai had a high degree of recognition of river network value but a low degree of satisfaction with the government’s actions and the current situation. The study also illustrated that the majority of respondents were willing to pay for river network protection. The mean WTP was 226.44 RMB per household per year. The number of years lived in Shanghai, the distance from the home to the nearest river, and the amount of the bid were important factors that influenced the respondents’ WTP. Suggestions for comprehensive management were proposed for the use of policy makers in river network conservation. PMID:23202821

  18. [Macrobenthic community structure and bioassessment for water quality of Banqiao Reservoir in Huaihe River basin].

    PubMed

    Sun, Wei-sheng; Gu, Qian-hong; Dong, Jing; Cheng, Qing-qing; Li, Xue-jun; Zhang, Man

    2015-09-01

    In order to demonstrate macrobenthic community structure dynamics and conduct a biological evaluation of water quality in Banqiao Reservoir, we collected seasonal samples from January to November 2014 across 15 sampling sites. A total of 17 species belonging to five families, four classes, and 3 phyla were identified, including 8 chironomidae, 4 oligochaeta and 5 mollusc. Bellamya aeruginosa, Corbicula fluminea, Branchiura sowerbyi, Pelopia sp. and Glyptotendipes sp. were the important species in Banqiao Reservoir. The total density, biomass and biodiversity of marobenthos showed significant spatial and temporal differences. ANOSIM analysis indicated that the macrobenthic community structure also differed significantly among regions and seasons, and the main contributing species were Glyptotendipes sp., Pelopia sp. and B. sowerbyi. The abundance-biomass comparison curves (ABC curves) indicated that the current macrobenthic community in Banqiao Reservoir was stable. Combined with the biodiversity index, biological pollution index (BPI) and Hilsenhoff biotic index (BI), it was suggested that Banqiao Reservoir suffered slight pollution. PMID:26785570

  19. 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.

  20. 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. PMID:27003063

  1. Sustainable Agricultural Paradigm Of mountain-Oasis-Ecotone-Desert System in Inland Manasi River Basin, Xinjiang Province, Northwest China

    NASA Astrophysics Data System (ADS)

    Liu, Huiming; Chen, Weiming; Dong, Xiaobin; Zhang, Xinshi

    Manasi River basin is located in the north foot of Tianshan Mountain, south edge of Zhunger Basin, central-north Xinjiang province, with typical aridfeatures of northern China. As the pressure on water resources in Manasi river basin is mounting because of rapid economic development, its conservation becomes ever more important. Climate change is another major threat to the future of water resources of Manasi river basin. How the water resourcechanges in Manasi river basin caused by glacial ablation, will affect the typical mountain-basin terrestrial ecosystems and agricultural production in Manasi river basin? What can we cope with the ecological issues caused by glacial ablation? In this paper we show how the water-saving stratagem such asconstructing reservoir in the mountainous region, building water pipes and be used in combination with the potential of water-saving resources, and build up sustainable agricultural paradigm of mountain-oasis-ecotone-desert system to coping with the glacier retreat and ablation. The potential of water-saving instudy area were calculated which presumed that if mountainous reservoirs and water pipes were built and water-saving technology were adopted, optimized eco-productive paradigm for mountain-basin system in Manasi river basin is proposed in desertification controlling, constructing artificial grassland in the oasis is the measure to protect vegetation in the downstream desert in Manasi river basin, and stopping grazing or forbidding grazing in the downstream of serious degradation in Manasi river basin.

  2. Projection of extreme precipitation in the context of climate change in Huang-Huai-Hai region, China

    NASA Astrophysics Data System (ADS)

    Yin, Jun; Yan, Denghua; Yang, Zhiyong; Yuan, Zhe; Yuan, Yong; Zhang, Cheng

    2016-03-01

    Based on the national precipitation dataset (0.5∘×0.5∘) 1961-2011, published by the National Meteorological Information Center of China and the five Global Climate Models provided by ISI-MIP, annual maximum precipitation for 1 day, 3 days and 7 days could be calculated. Extreme precipitation was fitted via Generalized Extreme Value (GEV) distribution to explore the changes of extreme precipitation with the return period of 20 years and 50 years during 1961-2000 and 2001-2050. Based on this, extreme precipitation projection in Huang-Huai-Hai region was done. The results showed that the five Global Climate Models could simulate the statistical features of extreme precipitation quite well, in which IPSL-CM5A-LR has the highest precision. Simulation of IPSL-CM5A-LR indicates that precipitation with the return period of 20 years and 50 years in the middle reaches of the Yellow River, middle and lower reaches of Huaihe River and plain area of the southern Haihe River will increase considerably in the future. Extreme precipitation in some of the places will even increase by more than 30%, which means that these places will face larger flood risk and their capacity to respond to flood disasters should be improved.

  3. 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.

  4. Morphometric studies of genus Placocheilus (Teleostei: Cypriniformes) from Red River, China.

    PubMed

    Zhou, Wei; Li, Min-Hui; Wang, Chun-Ping; Qi, Mi

    2015-11-18

    It is practically difficult to differentiate Placocheilus robustus and Placocheilus caudofasciatus from Red River drainage of China. Without stated reasons, P. robustus has been assumed as the synonyms of P. caudofasciatus. The present study aims to decipher the morphological differences between two species so as to provide reliable clues for their classification by multivariate morphometry. A total of 72 specimens of two species in genus Placocheilus were examined. Besides morphological character comparisons, 10 anatomic landmarks were utilized and 23 frame structures and 15 general characters measured. The scatter plot results of principal component analysis showed that all specimens were clustered together and could not be defined as two distinct species. No significant morphological differences existed in four diagnostic characters between P. robustus and P. caudofasciatus. Thus the results of the present study fail to support P. robustus as a valid and independent species.

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

    PubMed

    He, Xinran; Pang, Yong; Song, Xiaojuan; Chen, Binlin; Feng, Zhihua; Ma, Yuqin

    2014-03-15

    The contamination of surface sediments in Guan River Estuary, China, by polycyclic aromatic hydrocarbons (PAHs) has been fully investigated. Total concentrations of 21 PAHs ranged from 90 to 218 ng/g with an average of 132.7 ng/g, which is relatively low in comparison with other estuaries around the world. PAH concentrations appeared to be positively correlated with clay content and negatively correlated with sediment grain size. Source identification implied that the PAHs originated mainly from pyrolytic sources. However, source patterns may be continuously changed to a petrogenic origin due to the heavy ship traffic and continuous discharge of oily sewage in this area. The PAH levels were also compared with international Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated low negative effects for most individual PAHs. However, toxic effects related to FLO would occur occasionally in most locations in the estuary.

  6. Cumulative biophysical impact of small and large hydropower development in Nu River, China

    NASA Astrophysics Data System (ADS)

    Kibler, Kelly M.; Tullos, Desiree D.

    2013-06-01

    Support for low-carbon energy and opposition to new large dams encourages global development of small hydropower facilities. This support is manifested in national and international energy and development policies designed to incentivize growth in the small hydropower sector while curtailing large dam construction. However, the preference of small to large dams assumes, without justification, that small hydropower dams entail fewer and less severe environmental and social externalities than large hydropower dams. With the objective to evaluate the validity of this assumption, we investigate cumulative biophysical effects of small (<50 MW) and large hydropower dams in China's Nu River basin, and compare effects normalized per megawatt of power produced. Results reveal that biophysical impacts of small hydropower may exceed those of large hydropower, particularly with regard to habitat and hydrologic change. These results indicate that more comprehensive standards for impact assessment and governance of small hydropower projects may be necessary to encourage low-impact energy development.

  7. Structural control on lithofacies in the Zhu 1 depression, Pearl River Mouth Basin, South China Sea

    SciTech Connect

    Carnes, J.B.; Novitsky-Evans, J.C.; Schunk, D.J. )

    1994-07-01

    The structural framework of the Zhu 1 depression, Pearl River Mouth Basin, South China Sea, is expressed in terms of a half-graben rifting model, providing foundation for a predictive model of synrift lacustrine source rock distribution. The Zhu 1 depression includes a northern series of linked half grabens, a southern series of linked half grabens, and a central chain of intrabasinal ridges. The central ridge chain includes both horst blocks (termed high-relief accommodation zones or isolation ridges in the model) and antiforms (termed low-relief accommodation zones or interference ridges in the model). Major fluvial input was from the north, funneled into Zhu 1 through gaps (termed platforms in the model) created by offsets in the border faults of the northern series of half grabens. The central ridge chain is interpreted to have controlled sediment distribution within Zhu 1, periodically confining coarse terrigenous clastics within northern half grabens while lacustrine shales accumulated in southern half grabens.

  8. Water pollution and cyanobacteria's variation of rivers surrounding southern Taihu Lake, China.

    PubMed

    Sun, Mingyang; Huang, Linglin; Tan, Lisha; Yang, Zhe; Baig, Shams Ali; Sheng, Tiantian; Zhu, Hong; Xu, Xinhua

    2013-05-01

    The water quality and cyanobacterial variation of rivers surrounding southern Taihu Lake, China were purposively monitored from 2008 to 2010. Trophic level index (TLI) was used to evaluate the trophic levels of southern Taihu Lake. Results showed a considerable decline in the monitored data compared with 2007, and the data showed downward trends year after year. The TLI decreased from 55.6 to 51.3, which implied that southern Taihu Lake was mildly eutrophic. The water quality and cyanobacterial variation indicated a positive response to the adopted control measures in the southern Taihu Lake basin, but the intra- and inter-annual variability was still quite varied. High concentrations of nitrogen and phosphorus typically lead to algae outbreaks, however, the cyanobacteria growth may result in a decline of the concentration of nitrogen and phosphorus. Temperature and other weather conditions are also important factors for algae outbreaks; the risk of blue-green algal blooms still persists.

  9. Phosphorus characteristics, distribution, and relationship with environmental factors in surface sediments of river systems in Eastern China.

    PubMed

    Zhang, Wenqiang; Jin, Xin; Zhu, Xiaolei; Shan, Baoqing; Zhao, Yu

    2016-10-01

    Phosphorus (P) is an essential nutrient for aquatic organisms. However, too much P discharged into limnetic ecosystems can induce eutrophication. The concentration of P in freshwater ecosystems has escalated in Eastern China due to overuse of fertilizer and excess emission of sewage, which is the result of the development of industry and agriculture in this area. However, little is known about the P characteristics and its environmental factors in river systems. Here, we present the results of P characterization and its relationships with environmental factors in Eastern China by applying SMT and (31)P-NMR methods. The results showed that the concentrations of P in surface sediments varied with the river system, and more than 50 % of the samples had P concentrations exceeding 500 mg kg(-1). HCl-Pi was the dominant Pi in surface sediments, with the highest percentage (96.5 %) in the Yellow River System. Mono-P was the dominant Po in river sediments, followed by DNA-P. The PCA approach indicated that NaOH-Pi and ortho-P clustered in one group, with a second group including mono-P, diesters-P, and HCl-Pi. Phon-P and pyro-P belonged to different groups. On a regional scale, NaOH-Pi and Po showed a negative relationship with pH in sediments. Continuous eutrophication was induced by the presence of dams, and oxygen-consuming pollutants, such as NH3-N and CODcr, even when external P input was cut in heavily polluted rivers. The research revealed the characteristics of P in different river systems and proposed a conceptual model of P biogeochemical cycles in heavily polluted rivers. Results from this study may provide insight into P characteristics in Eastern China and would set a scientific basis for effective P management in developing countries. PMID:27380184

  10. Glacier retreat as a result of climate warming and increased precipitation in the Tarim river basin, northwest China

    NASA Astrophysics Data System (ADS)

    Liu, Shiyin; Ding, Yongjian; Shangguan, Donghui; Zhang, Yong; Li, Jing; Han, Haidong; Wang, Jian; Xie, Changwei

    The Tarim river basin, a river system formed by the convergence of nine tributaries, is the most heavily glacierized watershed in arid northwest China. In the basin, there are 11 665 glaciers with a total area of 19 878 km2 and a volume of 2313 km3. Glaciers in the basin play a significant role in the water resource system. It is estimated that they provide about 133 × 108 m3 of meltwater annually, contributing 39% of the total river runoff. Under the influence of global warming, northwest China has experienced a generally warmer and drier climate since the mid-19th century. However, a so-called 'warm and wet transition' has occurred since the late 1980s, evidenced by an increase in both precipitation and stream discharge in the Xinjiang Autonomous Region and neighboring regions. This paper describes how glaciers in the Tarim river basin have responded to such warming and increased precipitation, and the impact of these glacier changes. We analyzed the variations of more than 3000 glaciers since the 1960s using topographical maps, high-resolution satellite images and aerial photographs of the river basin. Our results indicate that glaciers in the basin have been mostly in retreat in the past 40 years, and ice wastage has significantly influenced water resources in the Tarim river basin. Estimation by a degree-day meltwater model shows the positive anomaly in stream runoff of the Tailan river can be partly attributed to the increase in glacier runoff (amounting to one-third of the stream discharge), and a rough estimation using observed average ablation on the termini of 15 glaciers in China verifies that the mass loss calculated by a glacier area-volume relation is reasonable.

  11. Spatial and temporal variations of the Longxi river channel in Sichuan province after the 2008 Wenchuan earthquake, China

    NASA Astrophysics Data System (ADS)

    Guo, B.; Xie, T.; Liu, G.

    2015-12-01

    Biyun Guo1,21College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316004,China; 2State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China Abstract: The great Wenchuan earthquake(Ms=8.0) occurred on May 12, 2008 in the southwestern China which triggerednumerous landslides and collapses that providedflows of an abundant unconsolidated material of debris. Landslides and debris flows were very active and caused river channel change over the affected mountain area. River channel changes due to the earthquake.Many potentially dangerous debris filledgullies have yet to be identified. In this paper,we present a study in the Longxi river watershed of the upper Min River located in Dujiangyan, discussingthe unconsolidated deposits and debris flows and their relationship with the riverbed changes. The secondary geological disasters triggered by this earthquake is delineated across the Longxi Rvier basin. Based on remote sensing and image interpretation of two QuickBird panchromatic images and comparison between two DEM data of different time periods, wevalidatedthe data with field survey by a differential GPS and laser rangefinder. Several variables were systematically measured (width, slope, bed level change, sediment size) along an18.22 km stretch of the river for specific sites. We have found from the study that: (1) the significant feature of geological disaster was near the Longxi river, where it had the mostintensity; (2) the longitudinal profile of channel bed was changed; (3) channel changes were associated with the land use and cover change, especially with the forest degradation and reforest, and post-quake reconstruction;(4)the landslide and debris flows caused the morphology changes in the Longxi River watershed, leading to sharp changes of the riverbed profiles and the slope in the upper and lower reaches. Keywords: Earthquake ;landslides; debris flows; channel change; riverbed evolution

  12. Dissolved insecticides and polychlorinated biphenyls in the Pearl River Estuary and South China Sea.

    PubMed

    Zhang, Z; Dai, M; Hong, H; Zhou, J L; Yu, G

    2002-12-01

    Persistent organic pollutants (POPs) such as organochlorine (OCl) insecticides and polychlorinated biphenyls (PCB), together with the new generation of organophosphorus (OP) insecticides, are of global concern, due to their widespread occurrence, persistence, bioaccumulation and hormone disruption potential. This paper represents an attempt to study the source and transportation of such pollutants in estuarine and coastal environments as an integrated ecosystem, by determining the levels of 18 OCl insecticides, 21 PCB congeners, and 17 OP insecticides in the Pearl River Estuary and South China Sea. The total concentrations varied from 126-1198 ng l(-1) for OCl insecticides, 33.38-1064 ng l(-1) for PCB congeners, and 4.44-6356 ng l(-1) for OP insecticides in the Pearl River Estuary. In comparison, their levels in the South China Sea were significantly lower, varying from 57.09-202 ng l(-1) for OCl insecticides, 21.72-144 ng l(-1) for PCBs, and 1.27-122 ng l(-1) for OP insecticides, respectively. The predominance of beta-HCH in HCHs, and DDE in DDTs in all water samples was clearly observed, suggesting beta-HCH and DDE's resistance to further degradation. The PCBs were dominated by those with 3-6 chlorines. The distribution characteristic of OP insecticides shows that five compounds (methamidophos, dimethoate, malathion, dichlorvos and omethoate) accounted for 56% and 72% of the total OP insecticide concentration. The relationship between pollutant concentrations and salinity in the estuary showed that they were all removed during the mixing process, therefore behaving non-conservatively.

  13. 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.

  14. The MARINA model (Model to Assess River Inputs of Nutrients to seAs): Model description and results for China.

    PubMed

    Strokal, Maryna; Kroeze, Carolien; Wang, Mengru; Bai, Zhaohai; Ma, Lin

    2016-08-15

    Chinese agriculture has been developing fast towards industrial food production systems that discharge nutrient-rich wastewater into rivers. As a result, nutrient export by rivers has been increasing, resulting in coastal water pollution. We developed a Model to Assess River Inputs of Nutrients to seAs (MARINA) for China. The MARINA Nutrient Model quantifies river export of nutrients by source at the sub-basin scale as a function of human activities on land. MARINA is a downscaled version for China of the Global NEWS-2 (Nutrient Export from WaterSheds) model with an improved approach for nutrient losses from animal production and population. We use the model to quantify dissolved inorganic and organic nitrogen (N) and phosphorus (P) export by six large rivers draining into the Bohai Gulf (Yellow, Hai, Liao), Yellow Sea (Yangtze, Huai) and South China Sea (Pearl) in 1970, 2000 and 2050. We addressed uncertainties in the MARINA Nutrient model. Between 1970 and 2000 river export of dissolved N and P increased by a factor of 2-8 depending on sea and nutrient form. Thus, the risk for coastal eutrophication increased. Direct losses of manure to rivers contribute to 60-78% of nutrient inputs to the Bohai Gulf and 20-74% of nutrient inputs to the other seas in 2000. Sewage is an important source of dissolved inorganic P, and synthetic fertilizers of dissolved inorganic N. Over half of the nutrients exported by the Yangtze and Pearl rivers originated from human activities in downstream and middlestream sub-basins. The Yellow River exported up to 70% of dissolved inorganic N and P from downstream sub-basins and of dissolved organic N and P from middlestream sub-basins. Rivers draining into the Bohai Gulf are drier, and thus transport fewer nutrients. For the future we calculate further increases in river export of nutrients. The MARINA Nutrient model quantifies the main sources of coastal water pollution for sub-basins. This information can contribute to formulation of

  15. The MARINA model (Model to Assess River Inputs of Nutrients to seAs): Model description and results for China.

    PubMed

    Strokal, Maryna; Kroeze, Carolien; Wang, Mengru; Bai, Zhaohai; Ma, Lin

    2016-08-15

    Chinese agriculture has been developing fast towards industrial food production systems that discharge nutrient-rich wastewater into rivers. As a result, nutrient export by rivers has been increasing, resulting in coastal water pollution. We developed a Model to Assess River Inputs of Nutrients to seAs (MARINA) for China. The MARINA Nutrient Model quantifies river export of nutrients by source at the sub-basin scale as a function of human activities on land. MARINA is a downscaled version for China of the Global NEWS-2 (Nutrient Export from WaterSheds) model with an improved approach for nutrient losses from animal production and population. We use the model to quantify dissolved inorganic and organic nitrogen (N) and phosphorus (P) export by six large rivers draining into the Bohai Gulf (Yellow, Hai, Liao), Yellow Sea (Yangtze, Huai) and South China Sea (Pearl) in 1970, 2000 and 2050. We addressed uncertainties in the MARINA Nutrient model. Between 1970 and 2000 river export of dissolved N and P increased by a factor of 2-8 depending on sea and nutrient form. Thus, the risk for coastal eutrophication increased. Direct losses of manure to rivers contribute to 60-78% of nutrient inputs to the Bohai Gulf and 20-74% of nutrient inputs to the other seas in 2000. Sewage is an important source of dissolved inorganic P, and synthetic fertilizers of dissolved inorganic N. Over half of the nutrients exported by the Yangtze and Pearl rivers originated from human activities in downstream and middlestream sub-basins. The Yellow River exported up to 70% of dissolved inorganic N and P from downstream sub-basins and of dissolved organic N and P from middlestream sub-basins. Rivers draining into the Bohai Gulf are drier, and thus transport fewer nutrients. For the future we calculate further increases in river export of nutrients. The MARINA Nutrient model quantifies the main sources of coastal water pollution for sub-basins. This information can contribute to formulation of

  16. Sustainable management of river oases along the Tarim River (SuMaRiO) in Northwest China under conditions of climate change

    NASA Astrophysics Data System (ADS)

    Rumbaur, C.; Thevs, N.; Disse, M.; Ahlheim, M.; Brieden, A.; Cyffka, B.; Duethmann, D.; Feike, T.; Frör, O.; Gärtner, P.; Halik, Ü.; Hill, J.; Hinnenthal, M.; Keilholz, P.; Kleinschmit, B.; Krysanova, V.; Kuba, M.; Mader, S.; Menz, C.; Othmanli, H.; Pelz, S.; Schroeder, M.; Siew, T. F.; Stender, V.; Stahr, K.; Thomas, F. M.; Welp, M.; Wortmann, M.; Zhao, X.; Chen, X.; Jiang, T.; Luo, J.; Yimit, H.; Yu, R.; Zhang, X.; Zhao, C.

    2015-03-01

    The Tarim River basin, located in Xinjiang, NW China, is the largest endorheic river basin in China and one of the largest in all of Central Asia. Due to the extremely arid climate, with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim rivers solely depends on river water. This is linked to anthropogenic activities (e.g., agriculture) and natural and semi-natural ecosystems as both compete for water. The ongoing increase in water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes have formed the consortium SuMaRiO (Sustainable Management of River Oases along the Tarim River; http://www.sumario.de), which aims to create a holistic picture of the availability of water resources in the Tarim River basin and the impacts on anthropogenic activities and natural ecosystems caused by the water distribution within the Tarim River basin. On the basis of the results from field studies and modeling approaches as well as from suggestions by the relevant regional stakeholders, a decision support tool (DST) will be implemented that will then assist stakeholders in balancing the competition for water, acknowledging the major external effects of water allocation to agriculture and to natural ecosystems. This consortium was formed in 2011 and is funded by the German Federal Ministry of Education and Research. As the data collection phase was finished this year, the paper presented here brings together the results from the fields from the disciplines of climate modeling, cryology, hydrology, agricultural sciences, ecology, geoinformatics, and social sciences in order to present a comprehensive picture of the effects of different water availability schemes on anthropogenic activities and natural ecosystems along the

  17. Ecosystem health assessment in the pearl river estuary of China by considering ecosystem coordination.

    PubMed

    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.

  18. 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

  19. Risks posed by trace organic contaminants in coastal sediments in the Pearl River Delta, China.

    PubMed

    Fung, C N; Zheng, G J; Connell, D W; Zhang, X; Wong, H L; Giesy, J P; Fang, Z; Lam, P K S

    2005-10-01

    Local marine environments in China's Pearl River Delta (PRD), the most rapidly developing region in one of the world's fastest growing economies, have been experiencing significant environmental stress during the past decades. This investigation was conducted to determine the status and trends of persistence organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and dioxin-related compounds in marine sediments collected from sixteen coastal stations in the Pearl River Delta (PRD) in March 2003. Elevated concentrations of PAHs (94-4300 ng/g), PCBs (6.0-290 ng/g), PHCs (14-150 microg/g), and DDTs (1.4-600 ng/g) were detected in sediment samples. In addition, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like activities in the sediment samples were estimated to range from 0.3 to 440 pg TCDD-EQ/g. Sediments collected from Xiashan contained the greatest concentrations of trace organic contaminations amongst all the sampling stations in the present study. The degree of trace organic contamination was, in general, more severe at stations situated along the west shores of the PRD than their counterparts in the east. A preliminary assessment was performed to examine the probable risks to the marine ecosystem due to POPs. The results showed that OC pesticide contamination in the PRD was particularly serious and might pose a threat to the health of the marine inhabitants. PMID:16199239

  20. 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

  1. Inequality and polarization analysis of urban water use in the Yangtze River Delta area, China.

    PubMed

    Zhang, Zhiguo; Shao, Yisheng

    2010-01-01

    Inequality and polarization are terms usually used to describe the overall dispersion of income distribution and the phenomenon of a divided society with a disappearing middle class and increasing rich and poor populations. However, these terms have seldom been used in water sciences. In this paper, the concepts of inequality and polarization are employed to analyze the distribution of urban water use of different cities. Using for reference the conception of Gini coefficient, the EUWU (Equality of Urban Water Use) model is built to analyze the equality of urban water use. And, the PUWU (Polarization of Urban Water Use) model based on exponential functions, which can limit the index of polarization to the range (0, 1) effectively, is built to analyze the polarization of urban water use. Inequality and polarization of resident, industrial and commercial water use in 16 cities in the Yangtze River Delta, the fastest growing region of China, are evaluated using the EUWU model and PUWU model, respectively. The results show that inequality of residential, industrial and commercial water use has decreased by 6.5%, 11.2% and 8.4%, while the index of polarization has increased by 3.9%, 3.8% and 0.1% in Yangtze River Delta area from 2001 to 2006.

  2. 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

  3. Ecosystem health assessment in the pearl river estuary of China by considering ecosystem coordination.

    PubMed

    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

  4. 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.

  5. Pollution from animal husbandry in China: a case study of the Han River Basin.

    PubMed

    Sun, Chen; Wu, Hongjuan

    2012-01-01

    Animal husbandry is one of the major agricultural pollution sources in China. The Xiangyang Reach of the Han River Basin was used as a case study to identify pollutants from animal rearing. The gross amount of pollutants from livestock and poultry rearing in the Xiangyang Reach was estimated using two empirical models with different data sets. The pig, cattle, sheep, and poultry population in 2009 amounted to 2.6, 0.6, 0.5, and 39.2 million head, respectively. The total annual pollutant loads generated from the feces and urine of livestock and poultry were 270,400 t of chemical oxygen demand; 228,900 t of biochemical oxygen demand; 26,500 t of ammonia nitrogen; 16,500 t of total phosphorus; and 63,900 t of total nitrogen. Approximately 12% of these pollutant loads were estimated to enter the Han River through the watershed outlet. Animal breeding has been one of the main pollution sources in this area, followed by domestic sewage and industrial wastewater. Cattle produced the most pollution, with the heaviest pollution load in downtown Xiangyang City. Several recommendations are presented to control the pollution caused by livestock and poultry breeding.

  6. 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

    2016-09-01

    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.

  7. Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China.

    PubMed

    Gong, Yao; Yu, Zhigang; Yao, Qingzhen; Chen, Hongtao; Mi, Tiezhu; Tan, Jiaqiang

    2015-08-14

    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.

  8. An Enhanced K-Means Algorithm for Water Quality Analysis of The Haihe River in China.

    PubMed

    Zou, Hui; Zou, Zhihong; Wang, Xiaojing

    2015-11-01

    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

  9. Urban household carbon emission and contributing factors in the Yangtze River Delta, China.

    PubMed

    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.

  10. 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.

  11. 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

  12. Characterization and source apportionment of water pollution in Jinjiang River, China.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Yue, Weifeng; Song, Liuting

    2013-11-01

    Characterizing water quality and identifying potential pollution sources could greatly improve our knowledge about human impacts on the river ecosystem. In this study, fuzzy comprehensive assessment (FCA), pollution index (PI), principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR) were combined to obtain a deeper understanding of temporal-spatial characterization and sources of water pollution with a case study of the Jinjiang River, China. Measurement data were obtained with 17 water quality variables from 20 sampling sites in the December 2010 (withered water period) and June 2011 (high flow period). FCA and PI were used to comprehensively estimate the water quality variables and compare temporal-spatial variations, respectively. Rotated PCA and receptor model (APCS-MLR) revealed potential pollution sources and their corresponding contributions. Application results showed that comprehensive application of various multivariate methods were effective for water quality assessment and management. In the withered water period, most sampling sites were assessed as low or moderate pollution with characteristics pollutants of permanganate index and total nitrogen (TN), whereas 90% sites were classified as high pollution in the high flow period with higher TN and total phosphorus. Agricultural non-point sources, industrial wastewater discharge, and domestic sewage were identified as major pollution sources. Apportionment results revealed that most variables were complicatedly influenced by industrial wastewater discharge and agricultural activities in withered water period and primarily dominated by agricultural runoff in high flow period.

  13. Urban household carbon emission and contributing factors in the Yangtze River Delta, China.

    PubMed

    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

  14. Effects of Nutrient on Algae Biomass during Summer and Winter in Inflow Rivers of Taihu Basin, China.

    PubMed

    Wu, Pan; Qin, Boqiang; Yu, Ge; Deng, Jianming; Zhou, Jian

    2016-07-01

    To explore the linkage of phosphorus (P), nitrogen (N) and phytoplankton during the summer and winter in the inflow rivers of the Taihu Basin, China, 51 main rivers were investigated in 2013 and 2014. The results showed that high P and N input deteriorated the water quality, and P primarily limited Chlorophyll a concentrations. Diatoms, green algae, and cyanobacteria were the dominant phyla, totaling 29 and 41 species in summer and winter, respectively. Total P negatively affected the phytoplankton diversity during summer and had a stronger positive relationship with richness than total N during winter. The P level restricted the biomass of dominant algae, and turbidity had a greater interaction with cyanobacteria. This study suggests that P drives the phytoplankton assemblages under N-rich environments in the inflow rivers during summer and winter, indicating the need for nutrient reduction and further monitoring of the rivers to improve the water ecology. PMID:27329063

  15. Effects of Nutrient on Algae Biomass during Summer and Winter in Inflow Rivers of Taihu Basin, China.

    PubMed

    Wu, Pan; Qin, Boqiang; Yu, Ge; Deng, Jianming; Zhou, Jian

    2016-07-01

    To explore the linkage of phosphorus (P), nitrogen (N) and phytoplankton during the summer and winter in the inflow rivers of the Taihu Basin, China, 51 main rivers were investigated in 2013 and 2014. The results showed that high P and N input deteriorated the water quality, and P primarily limited Chlorophyll a concentrations. Diatoms, green algae, and cyanobacteria were the dominant phyla, totaling 29 and 41 species in summer and winter, respectively. Total P negatively affected the phytoplankton diversity during summer and had a stronger positive relationship with richness than total N during winter. The P level restricted the biomass of dominant algae, and turbidity had a greater interaction with cyanobacteria. This study suggests that P drives the phytoplankton assemblages under N-rich environments in the inflow rivers during summer and winter, indicating the need for nutrient reduction and further monitoring of the rivers to improve the water ecology.

  16. Legacy and emerging halogenated organic pollutants in marine organisms from the Pearl River Estuary, South China.

    PubMed

    Sun, Run-Xia; Luo, Xiao-Jun; Tan, Xiao-Xin; Tang, Bin; Li, Zong-Rui; Mai, Bi-Xian

    2015-11-01

    A suite of legacy and emerging halogenated organic pollutants (HOPs) were measured in marine organisms (coastal fish and invertebrates) from the Pearl River Estuary, South China, to investigate the current contamination status after the Stockholm Convention was implemented in China. Dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were detected in all samples at concentrations of 54-1500, 16-700, and 0.56-59ng/g lipid weight, respectively. Dechlorane Plus (DP), decabromodiphenyl ethane (DBDPE), 2,3,5,6-tetrabromo-p-xylene (pTBX), and pentabromotoluene (PBT) were also found at concentrations of ND (non-detectable) to 37ng/g lipid weight. The concentrations of these investigated contaminants in the present study were at moderate levels, as compared with those reported in other regions. Significant interspecies differences were found in the levels of DDTs, PCBs, PBDEs and the alternative halogenated flame retardants (AHFRs). DDTs were the predominant HOPs in those species and represented >50% of the total HOPs, followed by PCBs, PBDEs, and AHFRs. The total estimated daily intakes (EDIs) of DDTs, PCBs, PBDEs, and AHFRs were 28, 12, 1.0, and 0.18 (ng/kg)/d, respectively, via seafood consumption. These concentrations are not expected to pose health risks to humans. PMID:26318119

  17. Weekend effect of temperature variation in the Yangtze River delta of China

    NASA Astrophysics Data System (ADS)

    Ma, Li; Jiang, Zhihong; Duan, Chunfeng; Miao, Qilong; Wang, Yong

    2009-03-01

    Study is performed of the weekly cycle of temperature indices (its diurnal range, mean, maximum and minimum) as well as cloudiness, solar radiation and air pollution index based on 1996-2005 surface observations and air pollution indexes from four big cities over the Yangtze River Delta of China. Results suggest that these temperature variations are featured by significant weekend effect (WE) in that these temperatures are higher at weekends than on workdays in summer as opposed to those in other seasons; the WE of diurnal maximum and minimum temperatures is much bigger at weekends and can be utilized as the WE index; during the long spell of holidays or festivities in China WE is remarkable, and especially in the Spring Festival and National Day holidays these temperatures are smaller compared to those 7 day before and after as opposed to the values during, and 7 days before/after, the May Day holidays; the temperature WE bears a close relation to aerosol concentration thanks to anthropogenic activities; in summer the indirect impacts of aerosols (aerosol - cloud interactions) due to abundant vapor play a dominant role and at weekends little aerosol is responsible for reduced cloudiness, allowing more solar radiation to strike the ground for the rise in all the temperatures; in the other seasons the direct and semi-direct effect of aerosol plays a predominant part, with the concentration of aerosols declining at weekends for reducing its ability to heat air and increasing cloudiness, thus leading to the decrease in all the temperature elements.

  18. Dynamics of soil organic and inorganic carbon in the cropland of upper Yellow River Delta, China

    PubMed Central

    Guo, Yang; Wang, Xiujun; Li, Xianglan; Wang, Jiaping; Xu, Minggang; Li, Dongwei

    2016-01-01

    Soil inorganic carbon (SIC) and organic carbon (SOC) are important carbon reservoirs in terrestrial ecosystems. However, little attention was paid to SIC dynamics in cropland. We conducted a survey in the upper Yellow River Delta of North China Plain. We collected 155 soil samples from 31 profiles, and measured SOC, SIC and soluble Ca2+ and Mg2+ contents. Our results showed that mean SOC content decreased from 9.30 g kg−1 near the surface to 2.36 g kg−1 in 80–100 cm whereas mean SIC content increased from 10.48 to 12.72 g kg−1. On average, SOC and SIC stocks over 0–100 cm were 5.73 kg C m−2 and 16.89 kg C m−2, respectively. There was a significantly positive correlation (r = 0.88, P < 0.001) between SOC and SIC in the cropland. We also found that SIC had a significantly positive correlation with both soluble Ca2+ (r = 0.57, P < 0.01) and Mg2+ (r = 0.43, P < 0.05). Our study suggested that increasing SOC might lead to an increase in SIC stocks in the cropland of North China Plain. This study highlights the importance of SIC in the carbon cycle of China’s semi-arid region. PMID:27782204

  19. Legacy and emerging halogenated organic pollutants in marine organisms from the Pearl River Estuary, South China.

    PubMed

    Sun, Run-Xia; Luo, Xiao-Jun; Tan, Xiao-Xin; Tang, Bin; Li, Zong-Rui; Mai, Bi-Xian

    2015-11-01

    A suite of legacy and emerging halogenated organic pollutants (HOPs) were measured in marine organisms (coastal fish and invertebrates) from the Pearl River Estuary, South China, to investigate the current contamination status after the Stockholm Convention was implemented in China. Dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were detected in all samples at concentrations of 54-1500, 16-700, and 0.56-59ng/g lipid weight, respectively. Dechlorane Plus (DP), decabromodiphenyl ethane (DBDPE), 2,3,5,6-tetrabromo-p-xylene (pTBX), and pentabromotoluene (PBT) were also found at concentrations of ND (non-detectable) to 37ng/g lipid weight. The concentrations of these investigated contaminants in the present study were at moderate levels, as compared with those reported in other regions. Significant interspecies differences were found in the levels of DDTs, PCBs, PBDEs and the alternative halogenated flame retardants (AHFRs). DDTs were the predominant HOPs in those species and represented >50% of the total HOPs, followed by PCBs, PBDEs, and AHFRs. The total estimated daily intakes (EDIs) of DDTs, PCBs, PBDEs, and AHFRs were 28, 12, 1.0, and 0.18 (ng/kg)/d, respectively, via seafood consumption. These concentrations are not expected to pose health risks to humans.

  20. A new framework to evaluate ecosystem health: a case study in the Wei River basin, China.

    PubMed

    Wu, Wei; Xu, Zongxue; Zhan, Chesheng; Yin, Xuwang; Yu, Songyan

    2015-07-01

    Due to the rapid growth of the population and the development of economies in the Guanzhong district, central China, the river ecosystem is gradually deteriorating, which makes it important to assess the aquatic ecosystem health and take measures to restore the damaged ecosystem. An index of catchment ecosystem health has been developed to assist large-scale management of watersheds by providing an integrated measure of ecosystem health, including aquatic and terrestrial ecosystem. Most researches focus on aquatic ecosystem or terrestrial ecosystem, but little research integrates both of them to assess the catchment ecosystem health. In this paper, we combine these two aspects into catchment ecosystem health. Ecosystem indicators derived from field samples and modeling are identified to integrate into ecosystem health. These included indicators of ecological landscape pattern (based on normalized difference vegetation index (NDVI), vegetation cover, dominance index, Shannon's diversity index, Shannon's evenness index, and fragmentation index), hydrology regime (based on 33 hydrological parameters), physical form condition (based on substrate, habitat complexity, velocity/depth regimes, bank stability, channel alteration), water quality (based on electrical conductivity (Cond), dissolved oxygen (DO), NH3_N, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand-permanganate (CODMn)), and biological quality (based on fish abundance). The index of ecosystem health is applied in the Guanzhong district, and the ecosystem health was fair. The ecosystem health in the upstream to Linjiacun (U-L) and Linjiacun to Weijiabao (L-W) reaches was in good situation, while that in Weijiabao to Xianyang (W-X), Xianyang-Weijiabao (X-W), and Weijiabao to Tongguan (W-T) reaches was in fair situation. There is a trend that the ecosystem health in the upstream was better than that in the downstream. The ecosystem health assessment is expected to play a key role in future

  1. 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. PMID:26544070

  2. Linking fluorescence spectroscopy to diffuse soil source for dissolved humic substances in the Daning River, China.

    PubMed

    Chen, Hao; Zheng, Bing-Hui; Zhang, Lei

    2013-02-01

    Dissolved organic matter collected in Daning River (China) in July 2009 was investigated with parallel factor analysis (PARAFAC) and fluorescence spectroscopy with the aim of identifying the origin of dissolved humic substance (HS) components. Two HS-like fluorescence components (peak M and C) with excitation/emission (ex/em) maxima at 305/406 nm and 360/464 nm showed relatively uniform distribution in the vertical direction for each sampling site but a trend of accumulation down the river, independent of the highly heterogeneous water environment as implicated by water quality parameters (i.e., water temperature, algae density, chlorophyll a, dissolved oxygen, dissolved organic carbon, pH, conductivity and turbidity), while an amino acid/protein-like component (peak T; ex/em = 280/334 nm) was quite variable in its spatial distribution, implying strong influence from point sources (e.g. sewage discharge) and local microbial activities. The fluorescence intensity (F max in Raman units) at these ex/em wavelength pairs fell in the range of 0.031-0.358, 0.051-0.224 and 0.026-0.115 for peak T, M and C, respectively. In addition, the F max values of peak C covaried with M (i.e. C = 0.503 ×M, p < 0.01, R (2) = 0.973). Taken together, these results indicate that peak M and C originated primarily and directly from the same soil sources that were diffusive in the catchment, but peak T was more influenced by local point sources (e.g. wastewater discharge) and in situ microbial activities. This study presents new insights into the currently controversial origin of some HS components (e.g."peak M", as commonly referred to in the literature). This study highlights that natural water samples should be collected at various depths in addition to along a river/stream flow path so as to better evaluate the origin of HS fluorescence components.

  3. 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

  4. Recent changes in precipitation extremes in the Heihe River basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Cheng, Aifang; Feng, Qi; Fu, Guobin; Zhang, Jiankai; Li, Zongxing; Hu, Meng; Wang, Gang

    2015-10-01

    Changes in rainfall extremes pose a serious and additional threat to water resources planning and management, natural and artificial oasis stability, and sustainable development in the fragile ecosystems of arid inland river basins. In this study, the trend and temporal variation of extreme precipitation are analyzed using daily precipitation datasets at 11 stations over the arid inland Heihe River basin in Northwest China from 1960 to 2011. Eight indices of extreme precipitation are studied. The results show statistically significant and large-magnitude increasing and decreasing trends for most indices, primarily in the Qilian Mountains and eastern Hexi Corridor. More frequent and intense rainfall extremes have occurred in the southern part of the desert area than in the northern portion. In general, the temporal variation in precipitation extremes has changed throughout the basin. Wet day precipitation and heavy precipitation days show statistically significant linear increasing trends and step changes in the Qilian Mountains and Hexi Corridor. Consecutive dry days have decreased obviously in the region in most years after approximately the late 1980s, but meanwhile very long dry spells have increased, especially in the Hexi Corridor. The probability density function indicates that very long wet spells have increased in the QilianMountains. The East Asian summer monsoon index and western Pacific subtropical high intensity index possess strong and significant negative and positive correlations with rainfall extremes, respectively. Changes in land surface characteristics and the increase in water vapor in the wet season have also contributed to the changes in precipitation extremes over the river basin.

  5. A new framework to evaluate ecosystem health: a case study in the Wei River basin, China.

    PubMed

    Wu, Wei; Xu, Zongxue; Zhan, Chesheng; Yin, Xuwang; Yu, Songyan

    2015-07-01

    Due to the rapid growth of the population and the development of economies in the Guanzhong district, central China, the river ecosystem is gradually deteriorating, which makes it important to assess the aquatic ecosystem health and take measures to restore the damaged ecosystem. An index of catchment ecosystem health has been developed to assist large-scale management of watersheds by providing an integrated measure of ecosystem health, including aquatic and terrestrial ecosystem. Most researches focus on aquatic ecosystem or terrestrial ecosystem, but little research integrates both of them to assess the catchment ecosystem health. In this paper, we combine these two aspects into catchment ecosystem health. Ecosystem indicators derived from field samples and modeling are identified to integrate into ecosystem health. These included indicators of ecological landscape pattern (based on normalized difference vegetation index (NDVI), vegetation cover, dominance index, Shannon's diversity index, Shannon's evenness index, and fragmentation index), hydrology regime (based on 33 hydrological parameters), physical form condition (based on substrate, habitat complexity, velocity/depth regimes, bank stability, channel alteration), water quality (based on electrical conductivity (Cond), dissolved oxygen (DO), NH3_N, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand-permanganate (CODMn)), and biological quality (based on fish abundance). The index of ecosystem health is applied in the Guanzhong district, and the ecosystem health was fair. The ecosystem health in the upstream to Linjiacun (U-L) and Linjiacun to Weijiabao (L-W) reaches was in good situation, while that in Weijiabao to Xianyang (W-X), Xianyang-Weijiabao (X-W), and Weijiabao to Tongguan (W-T) reaches was in fair situation. There is a trend that the ecosystem health in the upstream was better than that in the downstream. The ecosystem health assessment is expected to play a key role in future

  6. Radon and radium isotope assessment of submarine groundwater discharge in the Yellow River delta, China

    NASA Astrophysics Data System (ADS)

    Peterson, Richard N.; Burnett, William C.; Taniguchi, Makoto; Chen, Jianyao; Santos, Isaac R.; Ishitobi, Tomotoshi

    2008-09-01

    Naturally occurring chemical tracers were used to assess the magnitude of submarine groundwater discharge (SGD) during two different sampling periods at a coastal site south of the Yellow River delta, China. We used salinity and pH as indicators of the terrestrial and recirculated seawater components of discharging groundwater and radium isotopes to quantify offshore transport rates. We then used an hourly time series of multiple radium isotopes (224Ra, 223Ra, and 226Ra) to quantify SGD rates and also used 222Rn and seepage meters to independently quantify SGD rates as a comparison to the radium results. Offshore transport rates were found to range from 3.3 to 4.7 cm s-1. Modeled time series radium activities indicated average SGD rates ranging from 4.5 to 13.9 cm d-1 in September 2006 and from 5.2 to 11.8 cm d-1 in July 2007. Temporal trends associated with the radium approach agree with SGD patterns revealed by automated seepage meters deployed nearby, but the absolute fluxes are about 70% lower than those determined by the seepage meters. Modeled SGD rates based on 222Rn (mean = 13.8 cm d-1 in 2006 and 8.4 cm d-1 in 2007) agree with those determined by the radium analysis. Differences in derived SGD rates between the different radium isotopes (226Ra highest; 224Ra lowest) are likely results of uncertainties in the background activities and our limited selection of appropriate groundwater/pore water end-member values. Scaling our results to the entire Yellow River delta, we find SGD fluxes (and corresponding nitrate fluxes) 2-3 times that of the Yellow River.

  7. Signature of the Mekong River plume in the western South China Sea revealed by radium isotopes

    NASA Astrophysics Data System (ADS)

    Chen, Weifang; Liu, Qian; Huh, Chih-An; Dai, Minhan; Miao, Yu-Chun

    2010-12-01

    We investigated the distribution of 223Ra, 228Ra, and 226Ra in the surface water of the western South China Sea (SCS) during summer based on a 30 day cruise conducted in August-September 2007. The activities of 223Ra varied from almost undetectable to 0.74 disintegrations per minute (dpm)/100 L, and those of 228Ra varied from 12.2 to 61.5 dpm/100 L. Their spatial distribution was characterized by a jet of high 228Ra (>48 dpm/100 L) and 223Ra (>0.4 dpm/100 L) extending eastward from the Vietnam coast along ˜11°N, curling up in the vicinity of 112°E and swirling counterclockwise to form a cyclonic eddy with lower 228Ra (21-25 dpm/100 L) and 223Ra (0.04-0.14 dpm/100 L) at its center. High 226Ra (10-14 dpm/100 L) appeared in the eastward jet and decreased to 6.0-8.5 dpm/100 L along the track of the jet described above. The observed distribution of Ra isotopes was consistent with the pattern of the Southeast Vietnam Offshore Current in the western SCS in summer. The higher radium activities were in all likelihood derived from the Mekong River. Using a simple two-end-member mixing model based on the 228Ra/226Ra activity ratio and salinity, we calculated that approximately 53% of the surface water in the western SCS was originated from the Mekong River diluted water. Note that this estimation should be regarded as an upper limit due to the lack of sampling at its immediate source, the Mekong estuary. The data revealed that more than 2 weeks were required for the transportation of freshened water from the Mekong River's mouth several hundred kilometers to the western SCS.

  8. 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,

  9. 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.

  10. Linkages among vegetation, topography and climate variations over the Pearl River basin in southern China

    NASA Astrophysics Data System (ADS)

    Chen, J.; Sun, L.

    2008-12-01

    This study explores the relationships among vegetation, topography and climate variations over the Pearl River basin in southern China by analyzing a 25-year (1982-2006) monthly Normalized Difference Vegetation Index (NDVI) dataset. A data mining approach is used to group the NDVI and the topographic information of the Pearl River basin into different ecological zones according to twelve months of a year. It is found that elevation is the predominant factor in every month for grouping ecological zones. The elevation of the first split node of the ecological zones is high for the months from May to September and low in the months of March, April, October and November. In the vegetation leave growing month (April) and falling month (November), the numbers of the ecological zones recognized by the data mining approach are large compared with those detected in other months. This would reveal a respond of seasonal variations of vegetation life cycle. The relationships between the time series of the NDVI and weather variables, including precipitation, temperature and solar radiation from 1982 to 2002, are also analyzed. The correlation coefficients of the NDVI with solar radiation and temperature are positive in most months. However, the correlation coefficient of NDVI and precipitation is always negative. From these correlation coefficients, we found that the solar radiation is a dominate factor for vegetation growth in most area of the Pearl River basin, which matches the study of Nemani et al. (2003). Further, this study reveals that compared with those with low elevations, the ecological zones with high elevations are more sensitive to climate change. Nemani, R. R, C. D. Keeling, H. Hashimoto, and et al. (2003), Climate-driven increases in global terrestrial net primary production from 1982 to 1999, Science, 300, 1560-1563.

  11. Eco-Compensation in Multi-District River Networks in North Jiangsu, China

    NASA Astrophysics Data System (ADS)

    Xie, Rongrong; Pang, Yong; Li, Zhe; Zhang, Ninghong; Hu, Fenjuan

    2013-04-01

    Eco-compensation is a multi-disciplinary topic. There is no consensus on the issue of river eco-compensation across districts. Although policies regarding river eco-compensation have been issued in China since 2008, due to the high cost, eco-compensation has not been well implemented in the Taihu pilot region. Therefore, a simplified method based solely on water quality (both water quality and water volume included in the Taihu method) was proposed for North Jiangsu province (NJP). However, the formula was flawed and it led to payments being too low. Three problems need to be solved: (1) how to specify the eco-compensation areas; (2) how to test a reasonable eco-compensation model and (3) how to determine the compensation criterion. Solving these issues is already a priority. In this paper, three potential solutions surrounding eco-compensation are discussed: (1) three principles for selecting the representative eco-compensation areas are suggested; (2) the compensation calculation method based on contaminant flux above the ultra standard is revised and (3) a compensation criterion model based on the treatment costs of sewage is proposed. In the NJP case in 2009, the average eco-compensation criterion for chemical oxygen demand (COD) is 2,000 Chinese Yuan (CNY) per ton and ammonia nitrogen (NH4-N) and total phosphorus (TP) are 8,000 CNY and 80,000 CNY per ton, respectively. Five districts needed to be compensated. The payments in the revised scheme were 4.15-586 million CNY, which were 16-48 times greater than that in the draft method. The new method can provide an important template for managers when drafting river eco-compensation schemes.

  12. Eco-compensation in multi-district river networks in north Jiangsu, China.

    PubMed

    Xie, Rongrong; Pang, Yong; Li, Zhe; Zhang, Ninghong; Hu, Fenjuan

    2013-04-01

    Eco-compensation is a multi-disciplinary topic. There is no consensus on the issue of river eco-compensation across districts. Although policies regarding river eco-compensation have been issued in China since 2008, due to the high cost, eco-compensation has not been well implemented in the Taihu pilot region. Therefore, a simplified method based solely on water quality (both water quality and water volume included in the Taihu method) was proposed for North Jiangsu province (NJP). However, the formula was flawed and it led to payments being too low. Three problems need to be solved: (1) how to specify the eco-compensation areas; (2) how to test a reasonable eco-compensation model and (3) how to determine the compensation criterion. Solving these issues is already a priority. In this paper, three potential solutions surrounding eco-compensation are discussed: (1) three principles for selecting the representative eco-compensation areas are suggested; (2) the compensation calculation method based on contaminant flux above the ultra standard is revised and (3) a compensation criterion model based on the treatment costs of sewage is proposed. In the NJP case in 2009, the average eco-compensation criterion for chemical oxygen demand (COD) is 2,000 Chinese Yuan (CNY) per ton and ammonia nitrogen (NH4-N) and total phosphorus (TP) are 8,000 CNY and 80,000 CNY per ton, respectively. Five districts needed to be compensated. The payments in the revised scheme were 4.15-586 million CNY, which were 16-48 times greater than that in the draft method. The new method can provide an important template for managers when drafting river eco-compensation schemes.

  13. Unravelling the factors influencing flooding over the last 60 years in the Wei River Basin, China

    NASA Astrophysics Data System (ADS)

    Gai, Lingtong; Baartman, Jantiene E. M.; Mendoza-Carranza, Manuel; Wang, Fei; Ritsema, Coen J.; Geissen, Violette

    2016-04-01

    Flood hazard has become a growing concern in the Wei River Basin in China due to the extensive damage to private and public property under the pressure of extreme meteorological events and human intervention in the river basin. A better understanding of the influence of topographic, climatic and especially anthropogenic factors on hydrological discharge and flooding are important for flood regime and water resources management. This study is aiming at answering the questions why, where, when, and how flooding occurs. While most studies focus on single flood events, we aimed at unravelling a multitude of factors contributing to flooding over a decadal timespan. To be able to do this, we used conditional inference tree analysis, a promising method not often applied in hydrological studies. This method allows to rank all the influencing factors by its contribution to the occurrence of flooding therefore to identify the most important ones and spatially important subcatchments leading to flooding on both yearly and monthly bases in the basin. Dam construction period was identified as the most important factor (why) affecting flooding, followed by the elevation of the river outlet. The subcatchment farthest upstream in the basin (where) contributed the most to the discharge at the downstream floodplain. We then analyzed the impact of the periods of dam construction on the precipitation-discharge relationship using cross-correlation and double mass curves analysis, respectively. The results showed a smaller effect of dam construction on the time lags (when) between precipitation and discharge than on the effect of reducing the quantity of discharge (how).

  14. 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.

  15. Assessment of spatial and temporal patterns of green and blue water flows in inland river basins in Northwest China

    NASA Astrophysics Data System (ADS)

    Zang, C. F.; Liu, J.; van der Velde, M.; Kraxner, F.

    2012-03-01

    In arid and semi-arid regions freshwater resources have become scarcer with increasing demands from socio-economic development and population growth. Until recently, water research and management in these has mainly focused on blue water but ignored green water. Here we report on spatial and temporal patterns of both blue and green water flows simulated by the Soil and Water Assessment Tool (SWAT) for the Heihe river basin, the second largest inland river basin in Northwest China. Calibration and validation at two hydrological stations show good performance of the SWAT model in modelling hydrological processes. The total green and blue water flows were 22.09 billion m3 in the 2000s for the Heihe river basin. Blue water flows are larger in upstream sub-basins than in downstream sub-basins mainly due to high precipitation and large areas of glaciers in upstream. Green water flows are distributed more homogeneously among different sub-basins. The green water coefficient was 88.0% in the 2000s for the entire river basin, varying from around 80-90% in up- and mid-stream sub-basins to above 95% in downstream sub-basins. This is much higher than reported green water coefficient in many other river basins. The spatial patterns of green water coefficient were closely linked to dominant land covers (e.g. glaciers in upstream and desert in downstream) and climate conditions (e.g. high precipitation in upstream and low precipitation in downstream). There are no clear consistent historical trends of change in green and blue water flows and green water coefficient at both the river basin and sub-basin levels. This study provides insights into green and blue water endowments for the entire Heihe river basin at sub-basin level. The results are helpful for formulating reasonable water policies to improve water resources management in the inland river basins of China.

  16. Modeling of the Natural River-Aquifer Interactions -- A Simulation Extended to the Reclamation in Nantong City of China

    NASA Astrophysics Data System (ADS)

    Ji, P.; Chen, X.; You, J.; Cheng, C.; Liu, S.

    2009-12-01

    The competition for land uses in China intensified during the rapid development of the last two decades. The Jiangsu Province in the eastern China decided to develop a reclamation project in its coastal area in 2011. During the construction of highway and power plants, some geological and hydrological research work had been conducted but a lot of research questions about the tide-land interactions remain to be addressed. In China, researchers often use indoor experiments to simulate the coastal areas from river channel-aquifer interactions in laboratory. The dimensions of the experimental channels are, however, often limited to a small scale. In this study, we tried to use a natural river-aquifer system, with a relatively much larger scale compared to a laboratory channel-aquifer system, for simulation of the tide-land interactions. The study site is the Platte River near Kearney, Nebraska. An upstream reservoir released water cyclically and this water cycle is similar to the tidal process. Our study included direct-push techniques for permeameter tests to obtain the hydraulic conductivity of the streambed, monitoring the groundwater levels responding to daily changes of stream stages regulated by the upstream reservoir, and numerical modeling of the river-aquifer interactions. The soil layer and soil parameter analysis shows that the soil type and hydraulic conductivity at the study site are similar to the reclamation area in Nantong City of China. Thus the results from the Platte River site are applicable for simulating the flow dynamics and the groundwater level fluctuations caused by daily changes of tide level in the reclamation area. Other suggestions for dredger fill were put forward through the numerical simulation in the reclamation area.

  17. Hydrological Modeling of the Jiaoyi Watershed (China) Using HSPF Model

    PubMed Central

    Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001–2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R2), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin. PMID:25013863

  18. Hydrological modeling of the Jiaoyi watershed (China) using HSPF model.

    PubMed

    Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001-2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R (2)), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin. PMID:25013863

  19. Hydrological modeling of the Jiaoyi watershed (China) using HSPF model.

    PubMed

    Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001-2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R (2)), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin.

  20. Influence of the South-to-North Water Transfer and the Yangtze River mitigation projects on the water quality of Han River in China

    NASA Astrophysics Data System (ADS)

    Kuo, Yi-Ming; liu, Wenwen

    2016-04-01

    Algal bloom was occurred every year in the down stream of the Han River in recent five years. The operation of the Middle Route of China's South-to-North Water Transfer (MSNW) Project may affect the hydrological condition and self-purification of water body in the down and middle streams of the Han River, trigger algal bloom, and elevate the difficulty in the treatment of water pollutants, which is a crucial issue involved in ecology, environment, and economy. In this study, the monthly water samples were collected from the middle and down streams of Han River from July 2014 to December 2015. Factor Analysis and Cluster Analysis were applied to identify major pollution types and areas and determine the reasons influencing the variations of water quality in the down and middle streams of the Han River. The results show that whole monitoring period can be divided into three periods as different pollution levels. The factor analysis distinguishes three pollution types (inorganic pollution, organic pollution, and agricultural pollution) and thier contributions on Han River water quality in dry and wet seasons. Industrial areas are influenced by inorganic pollution and cultivated lands are influenced by agricultural pollution. The water quality in wet season is significantly affected by flow rate, which was sometimes controlled by two projects. The heavy polluted water may be diluted by high flow volume.

  1. Long-term variations and causal factors in nitrogen and phosphorus transport in the Yellow River, China

    NASA Astrophysics Data System (ADS)

    Tao, Yu; Wei, Meng; Ongley, Edwin; Li, Zicheng; Jingsheng, Chen

    2010-02-01

    This paper is to examine the water quality of the Yellow River basin on the basis of collated data of nitrogen (40 years) and phosphorus (20 years), and also of the relevant chemical fertilizer application, population, and industrial wastewater, etc. Relationship among these elements was discussed in order to explore their causal links, in relation to the temporal variation of nitrogen and phosphorus transportation. Results indicate that the transported nitrogen load in the lower Yellow River has had an increasing trend during the past 40 years but declined considerably in the later 1990s due to the reduction in flow discharge that led to desiccation of the lower reaches of the Yellow River. Whereas, nitrogen contribution to the estuary from Huayuankou to Lijin reach was minus due to the large amount of water diversion from the Yellow River for irrigation purpose. Phosphorus content fluctuated within a certain range without any tendency, but also decreased in the later 1990s due to the desiccation in the lower reaches. Our analysis indicates that nitrogen load in the Yellow River has been mainly impacted by population growth and nitrogen fertilizer application, but showed no statistically significant relationship with wastewater loads. In contrast, total phosphorus content in the Yellow River showed no relationship with population, fertilizer use and wastewater discharge in the basin, but presented significant correlation with suspended solids concentration of the Yellow River. Calculations indicate that the phosphorus content in suspended solids of the Yellow River was 0.54 g/kg, which is quite close to the background value of phosphorus in the soil of the Loess Plateau - the intensive soil erosion area in China, through which the Yellow River flows. Therefore, we conclude that phosphorus transportation in the Yellow River is dominantly controlled by soil erosion from the Loess Plateau. The results are significant for estuarine management in that nitrogen, a key

  2. Drainage evolution of the Heihe River in western Hexi Corridor, China, derived from sedimentary and magnetostratigraphic results

    NASA Astrophysics Data System (ADS)

    Pan, Baotian; Chen, Dianbao; Hu, Xiaofei; Cao, Xilin; Chen, Jinjun; Mao, Junwei

    2016-10-01

    The uplifting of the Tibetan Plateau has significantly changed the environment in surrounding areas by delivering abundant water and sediment. The Heihe River draining the Qilian Shan in the NE Tibetan Plateau acts as a dominant sediment routing system from the uplifted NE Tibetan Plateau to the Hexi Corridor as well as the Badain Jaran Desert. Reconstructing the evolution of the Heihe River could provide evidence for the birth of the Badain Jaran Desert and enhance the understanding of sedimentary basin fill and the relationship between tectonism, drainage evolution and environmental changes. With this aim, two parallel cores (DWJ and XKJD with depths of 140 and 68.2 m, respectively) were drilled in the floodplain of the Heihe River. The facies analysis of the sedimentary sequences from the drilling cores showed that the sedimentary environment changed from the lake system to a delta system and finally to a fluvial system at the depths of ∼133.3 and ∼68 m, respectively. The magnetostratigraphic results revealed ages of approximately 1.75 and 1.12 Ma for the DWJ and XKJD cores, respectively, and an age of approximately 1.1 Ma for the transition from delta to fluvial environment in both the cores. The change of the sedimentary environment at approximately 1.1 Ma was caused by the formation of the integrated Heihe River. The integrated Heihe River may have developed via mechanisms such as river capture and river diversion due to the uplifting of the North Qilian Shan and the Longshou Shan. The present study suggested that the formation of large inland rivers, such as the Heihe River and the Shiyang River in NW China, played an important role in the evolution of the deserts and the Loess Plateau.

  3. Estimating surface water area changes using time-series Landsat data in the Qingjiang River Basin, China

    NASA Astrophysics Data System (ADS)

    Du, Zhiqiang; Linghu, Bin; Ling, Feng; Li, Wenbo; Tian, Weidong; Wang, Hailei; Gui, Yuanmiao; Sun, Bingyu; Zhang, Xiaoming

    2012-01-01

    The Qingjiang River Basin, which is 423 km long in the Hubei province, China, is the first large tributary of the Yangtze River below the Three Gorges. The Qingjiang River Basin surface water area monitoring plays an important role in the water resource management strategy and regular monitoring management of the Yangtze River watershed. Hydropower cascade exploitation, which started in 1987, has formed three reservoirs including the Geheyan reservoir, the Gaobazhou reservoir, and the Shuibuya reservoir in the midstream and downstream of the Qingjiang River Basin. They have made a great impact on surface water area changes of the Qingjiang River Basin and need to be taken into account. We monitor the Qingjiang River Basin surface water area changes from 1973 to 2010. Ten scenes from the Multispectral Scanner System (MSS), seven scenes from the Thematic Mapper (TM), and two scenes from the Enhanced Thematic Mapper Plus (ETM+) remote sensing data of Landsat satellites, the normalized different water index (NDWI), the modified NDWI (MNDWI), and Otsu image segmentation method were employed to quantitatively estimate the Qingjiang River Basin surface water area in the 1970s, 1980s, 1990s, and 2000s, respectively. The results indicate that the surface water area of the Qingjiang River Basin shows a growing trend with the hydropower cascade development from the 1980s to the first decade of the 21st century. The study concluded the significance of human activities impact on surface water spatiotemporal distribution. Surface water accretion is significant in most parts of the Qingjiang River Basin and might be related to the constructed cascade hydropower dams.

  4. 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.

  5. 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. PMID:25427825

  6. 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.

  7. 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. PMID:26735186

  8. Distribution, source apportionment, and transport of PAHs in sediments from the Pearl River Delta and the northern South China Sea

    SciTech Connect

    Luo, X.J.; Chen, S.J.; Mai, B.X.; Sheng, G.Y.; Fu, J.M.; Zeng, E.Y.

    2008-07-15

    Polycyclic aromatic hydrocarbons (PAHs) were measured in 59 surface sediments from rivers in the Pearl River Delta and the northern continental shelf of the South China Sea. Total PAH concentrations varied from 138 to 6,793 ng/g dry weight. The sources of PAH inputs to sediments in the Pearl River Delta were qualitatively and quantitatively determined by diagnostic ratios and principal components analysis with multiple linear regression. The results showed that on average coal and wood combustion, petroleum spills, vehicle emissions, and nature sources contributed 36%, 27%, 25%, and 12% of total PAHs, respectively. Coal and biomass combustion was the main source of PAHs in sediments of the South China Sea, whereas petroleum combustion was the main source of pyrolytic PAHs in riverine and estuarine sediments of the Pearl River Delta. Perylene was formed in situ in river sediments and then transported to coastal areas along with other PAHs. The relative abundance of perylene from five-ring PAHs can be used to estimate the contribution of riverine-discharged PAHs to coastal sediments.

  9. Late Pleistocene and Holocene palaeoflood events recorded by slackwater deposits in the upper Hanjiang River valley, China

    NASA Astrophysics Data System (ADS)

    Liu, Tao; Huang, Chun Chang; Pang, Jiangli; Zha, Xiaochun; Zhou, Yali; Zhang, Yuzhu; Ji, Lin

    2015-10-01

    Slackwater palaeoflood deposits (SWDs) were identified in a bedrock gorge in the upper reaches of the Hanjiang River of central China. The Hanjiang River is the longest tributary of the Yangtze River, one of the most flood-prone rivers in China, and the main source of water for the South-to-North Water Transfer Project (SNWTP). Three main loess-soil profiles with late Pleistocene and Holocene palaeoflood SWD bedsets were found. Palaeoflood SWDs identified interbedded in the loess-soil sequence of late Pleistocene and Holocene age within the cliff riverbanks were studied by field observations and laboratory analysis, including particle-size distribution and Optically Stimulated Luminescence (OSL) dating. At least eight extreme flood events documented by palaeoflood SWDs occurred in the Wufeng reaches of the upper Hanjiang River. The discharge estimation associated with palaeoflood SWDs, indicates that the minimum flood peak discharges of these flood episodes range from 42,220 to 63,400 m3/s. The SWDs were OSL dated to between 12,600-12,400, 4200-4000, 3200-2800 and 1900-1700 a BP and these dates were corroborated with pottery remains retrieved from the profiles and dated by archaeological methods. These periods of increased flood magnitude coincide with contemporaneous global climatic events dated to 12,500, 4200, 3100 and 1900 a BP worldwide. These findings are of great significance in understanding the interactions between hydrological systems and climatic change in monsoonal zones.

  10. Occurrence and possible sources of polychlorinated biphenyls in surface sediments from the Wuhan reach of the Yangtze River, China.

    PubMed

    Yang, Zhifeng; Shen, Zhenyao; Gao, Fan; Tang, Zhenwu; Niu, Junfeng

    2009-03-01

    Twenty-seven surface sediment samples were collected from the mainstream and eight tributaries of the Wuhan reach of the Yangtze River, China, in 2005, in order to assess the distribution, possible sources, and potential risk of polychlorinated biphenyls (PCBs) in the environment. The total concentrations of PCBs (the sum of 39 congeners) ranged from 1.2 to 45.1 ng g(-1) dry weight, with a mean value of 9.2 ng g(-1). Sediment samples with the highest PCB concentrations came from the tributary sites, which are closer to PCB sources. Conversely, PCB concentrations in the sediment from the mainstream sites of Yangtze River were relatively low. The observed PCB levels were higher than those found in the sediments of other rivers in China, but lower than those in river sediments from other urban areas and harbors around the world. Low-chlorinated PCBs, dominated by tetra-PCBs and penta-PCBs, were identified as being prevalent in the surface sediments. Correlation analyses between the PCBs and the geochemistry and heavy metal content of the sediments suggest that the washing of these compounds from the land into the river by floods and heavy rains, or industrial wastewater and domestic sewage, may be the major sources of the PCBs. According to established sediment quality guidelines, the risk of adverse biological effects from the levels of PCBs recorded at most of the studied sites should be insignificant, although the higher concentrations at other sites could cause acute biological damage. PMID:19108865

  11. Characteristics of water isotopes and hydrograph separation during the spring flood period in Yushugou River basin, Eastern Tianshans, China

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyan; Li, Zhongqin; Ross, Edwards; Tayier, Ruozihan; Zhou, Ping

    2015-02-01

    Many of the river basins in northwest China receive water from melting glaciers and snow in addition to groundwater. This region has experienced a significant change in glacier and snowpack volume over the past decade altering hydrology. Quantifying changes in water resources is vital for developing sustainable strategies in the region. During 2013, a water-isotope source apportionment study was conducted during the spring flood in the Yushugou River basin, northwestern China. The study found significant differences in water isotopes between river water, snowmelt water, and groundwater. During the study period, the isotopic composition of groundwater remained relatively stable. This stability suggests that the groundwater recharge rate has not been significantly impacted by recent hydro-climatic variability. The river water flow rate and water δ 18O displayed an inverse relationship. This relationship is indicative of snowmelt water injection. The relative contribution of the two sources was estimated using a two-component isotope hydrograph separation. The contribution of snowmelt water and groundwater to Yushugou River were ˜63% and ˜37%, respectively. From the study, we conclude that snowmelt water is the dominant water source to the basin during the spring melt period.

  12. Distribution, source apportionment, and transport of PAHs in sediments from the Pearl River Delta and the Northern South China Sea.

    PubMed

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

    2008-07-01

    Polycyclic aromatic hydrocarbons (PAHs) were measured in 59 surface sediments from rivers in the Pearl River Delta and the northern continental shelf of the South China Sea. Total PAH concentrations varied from 138 to 6,793 ng/g dry weight. The sources of PAH inputs to sediments in the Pearl River Delta were qualitatively and quantitatively determined by diagnostic ratios and principal components analysis with multiple linear regression. The results showed that on average coal and wood combustion, petroleum spills, vehicle emissions, and nature sources contributed 36%, 27%, 25%, and 12% of total PAHs, respectively. Coal and biomass combustion was the main source of PAHs in sediments of the South China Sea, whereas petroleum combustion was the main source of pyrolytic PAHs in riverine and estuarine sediments of the Pearl River Delta. Perylene was formed in situ in river sediments and then transported to coastal areas along with other PAHs. The relative abundance of perylene from five-ring PAHs can be used to estimate the contribution of riverine-discharged PAHs to coastal sediments.

  13. Monitoring and modeling of cold region hydrological processes in a high mountain river basin in the upstream area of the Heihe River Basin of China

    NASA Astrophysics Data System (ADS)

    Li, X.; Che, T.; Li, H.; Jin, R.; Liu, S.; Huang, C.

    2015-12-01

    We provide an overview of a high mountain river basin observing system in the Qilian Mountains of China. Mountain cryosphere is very sensitive to climate change, however, monitoring and modeling of cryospheric process and its interaction with hydrology and ecology needs to be further strengthened. We establish a multi-scale high mountain river basin observing system in the upstream area of the Heihe River Basin, Qilian Mountains of China. This system consists of flux towers on alpine tundra, alpine meadow and alpine steppes, a network of automatic meteorological stations, a wireless sensor network of soil moisture, soil temperature, snow depth, and precipitation, and two super observatories for monitoring snow and frozen soil, respectively. Super-high resolution (1 meter) DEMs of four experiment sub-watersheds (each about 20-40 km2) within this river basin were obtained via airborne LiDAR remote sensing.We introduce the data obtained since 2012 and present some preliminary modeling and data assimilation results. The results show that runoff, precipitation, snowmelt, and glacier melt keep increasing in the upstream area of the Heihe River Basin due to a warming climate. The ratio of snowmelt in total runoff has increased and the onset of snowmelt has gone ahead. The contribution of glacier melt to total runoff has almost doubled in the past decade. Frozen soil melt advances in time as well, and it may also contributes to the increase of the portion of baseflow in total runoff.This observatory has joined the International Network for Alpine Research Catchment Hydrology (NARCH) and will work as a unique site to monitor cryospheric and hydroclimatological changes in very high mountains.

  14. Variability and trend in the hydrology of the Yangtze River, China: Annual precipitation and runoff

    NASA Astrophysics Data System (ADS)

    Chen, Jing; Wu, Xiaodan; Finlayson, Brian L.; Webber, Michael; Wei, Taoyuan; Li, Maotian; Chen, Zhongyuan

    2014-05-01

    The catchment of the Yangtze River in China has a long history of human occupation and the intensity of human impacts has increased markedly since economic reforms began in the late 1970s. In order to try to assess the impact of these changes on the hydrology of the river, we analyse both the annual flows of the Yangtze River and annual temperature and precipitation for the Yangtze catchment for the period 1955-2011 and for the three sections of the catchment, Upper, Middle and Lower as defined by the location of the gauging stations at Yichang, Hankou and Datong respectively. Mean annual temperature increases downstream from 12.7 °C in the Upper to 16.0 °C in the Lower section. A significant increasing trend in mean annual temperature is detected over the period 1955-2011 in the whole catchment and all subsections. Mean annual precipitation for the whole catchment is 1045 mm ranging from 859 mm in the elevated Upper section to 1528 mm in the Lower section. Precipitation variability is low by world standards with an annual Cv of 0.066. Using the Mann-Kendal and Rank Sums tests we do not find any trend in precipitation in the catchment. Mean annual runoff for the whole catchment is 515 mm ranging from 421 mm in the Upper Catchment to 838 mm in the Lower Catchment. Runoff variability is also low by world standards with an annual runoff Cv of 0.129. For the Middle Catchment we find a small but statistically significant increase in runoff and the runoff ratio over the period 1955-2011, possibly caused by change in the nature of the surface due to accelerated urbanization post 1980 and increased area of water storage. Overall, annual runoff in the Yangtze River shows little response to the major changes occurring in the basin. In a multiple correlation analysis of discharge, precipitation, dam volume, population and GDP, only precipitation is significantly correlated with discharge, explaining 80% of the variance. Widespread reporting of the impact of development on

  15. A Long-term Regional Simulation and Observations of the Hydroclimate in China

    SciTech Connect

    Qian, Yun; Leung, Lai R.

    2007-07-24

    Driven by the complex topography, inhomogeneous land surface conditions and large-scale circulation exhibiting strong variability at various time scales, the hydroclimate of China presents many unique features and poses a great challenge for climate modeling. This paper provides detailed analyses of observations and a 20-year regional climate simulation to improve our understanding of the diverse hydroclimate regimes in China. Eastern China is greatly influenced by the East Asian monsoon, leading to heavy summer rainfall that exhibits large variations at the intraseasonal and interannual time scales. The Hai River and Huaihe River basins feature the largest interannual variations in summer rainfall, with the Middle and Lower Yangtze River and Pearl River basins showing the next highest variability. In the wettest regions of the Middle and Lower Yangtze River basin and Southeast Coast, the land surface plays a comparatively passive role as evaporation is not limited by soil moisture, and boundary layer and precipitation processes are only weakly influenced by soil wetness. In contrast, northern and western China are marked by dryer and less cloudy conditions, and interannual variations in summer rainfall are typically half of that in eastern China. Precipitation is largely balanced by evapotranspiration. The land surface plays a more active role in the water cycle in these regions. This is supported by the strong correlations between soil moisture and sensible heat flux, evaporative fraction, and mixed layer depth, indicating a strong influence of soil wetness on atmospheric stability and precipitation processes. The overall spatial distribution, seasonal variations, and extreme precipitation are well simulated by the regional climate model. However, the simulation produces more rainfall associated with the lower rain rates in central and southern China. This suggests that some mechanisms responsible for heavy rainfall may not be properly simulated by the model due

  16. Modeling the mass flux budgets of water and suspended sediments for the river network and estuary in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Hu, Jiatang; Li, Shiyu; Geng, Bingxu

    2011-11-01

    A coupled physical and sediment transport model was used to study the mass flux budgets of water and suspended sediments in the Pearl River Delta (PRD). The coupled model incorporates the Pearl River network, the Pearl River Estuary (PRE) and adjacent coastal waters in one overall modeling system. The results indicate that the river network and the PRE both have pronounced temporal and spatial variability in water and sediment fluxes, in hydrodynamic features and in sediment depositional patterns. In the river network, the riverine fluxes of water and suspended sediments are dominated by the West River, and those that are exported to the PRE (defined as the estuarine fluxes) are primarily contributed by Modaomen. The river outlets are highly responsive to the main tributaries in terms of water and sediment fluxes, revealing a close coupling between the upstream and the downstream boundaries. Most of the annual riverine and estuarine fluxes occur in the wet season, approximately 74% of the water flux and riverine and estuarine fluxes of suspended sediments of 94% and 87%, respectively. Although the water and sediment transport is dominated by river discharge, the tides are also an important factor, especially in regulating the structures of seasonal deposits in the river network (deposition in the wet season and erosion in the dry season). In the PRE, various types of physical forcing, including river discharge, monsoon winds, tides, coastal currents and the gravitational circulation associated with a density gradient, operate in concert to control the water and sediment transport in the estuary. Most of the oceanic fluxes of water and suspended sediments entering the South China Sea take place in the dry season and are primarily conveyed by strong western coastal currents. The PRE is a sedimentary system characterized by intricate depositional structures in space and time. Several depositional patterns and the associated driving mechanisms were identified. A fan

  17. Conventional and emerging halogenated flame retardants (HFRs) in sediment of Yangtze River Delta (YRD) region, East China.

    PubMed

    Zhu, Bingqing; Lam, James C W; Yang, Shouye; Lam, Paul K S

    2013-09-01

    The occurrence and distribution of polybrominated diphenyl ethers (PBDEs) and eleven non-PBDE halogenated flame retardants (HFRs) were investigated through the collection of marine and river sediment from Yangtze River Delta (YRD), East China. Among them, PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) were the three predominant HFRs with the highest detection frequencies in the sediment. Significant correlation between PBDEs and DBDPE indicated that they may have the similar emission sources. The production and use of DBDPE is growing rapidly and comparable concentrations between PBDEs and DBDPE in YRD sediment may suggest that DBDPE will likely become one of the major HFRs emerging in the environment in China. Of the seven detected non-PBDE HFRs, this is the first time that TBECH was reported in the Chinese environment and its predominance and prevalence in the YRD may imply its extensive use in these areas.

  18. Occurrence, distribution, and sources of six phenolic endocrine disrupting chemicals in the 22 river estuaries around Dianchi Lake in China.

    PubMed

    Wang, Bin; Huang, Bin; Jin, Wei; Zhao, Shimin; Li, Farong; Hu, Ping; Pan, Xuejun

    2013-05-01

    The objectives of this study are to track the occurrence, distribution, and sources of phenolic endocrine disrupting compounds (EDCs) in the 22 rivers around Dianchi Lake in China, to estimate the input and output amounts of phenolic EDCs in the water system, and to provide more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment. Six phenolic EDCs were systematically evaluated in water and surface sediment in the estuaries of those rivers. The water and sediment samples were preconcentrated by solid-phase extraction system and microwave-assisted extraction system, respectively. Phenolic EDCs were analyzed by GC-MS (Thermo Fisher Scientific, USA) after derivatization. Phenolic EDCs were found ubiquitously in the aquatic environment. The total concentrations ranged from 248 to 4,650 ng/L in water, and 113 to 3,576 ng/g dry weight in surface sediment. The residue amount of phenolic EDCs in Dianchi Lake was 258 kg/a. Concentrations of the phenolic EDCs in the Lake decreased with increase in distance to the estuaries of those rivers which run through urban and industrial areas. The rivers seriously contaminated by phenolic EDCs were Xin River, Yunliang River, Chuanfang River, Cailian River, Jinjia River, Zhengda River, and Daqing River which run through the old area of Kunming City. Satisfying correlations were observed between the concentrations of the target compounds in water and in surface sediment. NP1EO, NP2EO, and BPA were identified as the three predominant phenolic EDCs. There were significant correlations between phenolic EDCs and many basic water quality parameters. Urban and industrial areas are the major contributors for phenolic EDCs, especially in Kunming City. Compositional profiles of phenolic EDCs in surface sediment were similar to those in river water. The concentrations of phenolic EDCs in the rivers located in the northwest part of the valley were very high, and posed a potential

  19. Assessing ecological land use and water demand of river systems: a case study in Luanhe River, North China

    NASA Astrophysics Data System (ADS)

    Yan, D. H.; Wang, G.; Wang, H.; Qin, T. L.

    2012-08-01

    Economic and social development has greatly increased ecological water demand and modified land use of river systems worldwide, causing overall degradation of many of these systems. In this study, theoretical and technical frameworks for regionalization on the eco-environmental function of river systems are formulated and applied to the Luanhe River system. Based on its eco-environmental functions, this river can be regionalized into four types of first-class functional areas: ecological preservation areas, habitat restoration areas, ecological buffer areas and development and utilization areas. Considering the overall eco-environmental functions, we assessed the ecological land use of the Luanhe River system. The total area of basic ecological land use is 876.98 km2; the restrictive ecological land use is 1745.52 km2; ecological land use of the river system returned from farmland is 284.25 km2; and that returned from construction land is 17.35 km2. The average minimum ecological flow of mainstreams in upper and middle reaches of the Luanhe River is 4.896 m3 s-1 based on the habitat method. And the recommended minimum and suitable annual ecological water demand of channels in the lower reaches are 391 million m3 and 819.5 million m3, respectively. The evaporation and seepage consumption and vegetation consumption in riparian zones of the Luanhe River system are approximately 132.6 million m3 and 145.3 million m3 per year, respectively. Our results suggest that is crucial to regulate the instream ecological water use of the Luanhe River's mainstream starting from the Panjiakou-Daheiting Reservoir system. We recommend accelerating ecological land-use planning and strengthening the regulation of ecological water use on this river system focusing on important lower reaches under the condition of competitive water demand.

  20. Application of positive matrix factorization to source apportionment of surface water quality of the Daliao River basin, northeast China.

    PubMed

    Li, Huiying; Hopke, Philip K; Liu, Xiande; Du, Xiaoming; Li, Fasheng

    2015-03-01

    Surface water monitoring networks play an important role in the stream water quality management. Since a time series of data is obtained from the monitoring network, multivariate statistical techniques can be used to identify important factors or pollution sources of water system. Positive matrix factorization (PMF) is an improved factor analysis tool that has had limited application to water systems. The objective was to apply PMF to monitoring data to apportion water pollution sources in the Daliao River (DLR) basin. The DLR basin includes the Hun and Taizi River catchments in northeast China. This basin is densely populated and heavily industrialized. Fourteen monitoring stations located on the two rivers were used for monitoring 13 physical and chemical parameters from 1990 to 2002. Results show that five sources/processes in the Hun River and four in the Taizi River were identified by marker species and spatial-temporal variations of resolved factors, including point and nonpoint sources for both rivers. In addition, the industrial pollution source emission inventory data were used to compare with the resolved industrial sources. Results reveal that chemical transformations have influenced some chemical species. However, this influence is small compared with observed seasonal variations. Therefore, identification of pollution point and nonpoint sources by their seasonal variations is possible, which will also aid in water quality management. The spatial variation of the industrial pollutants typically corresponded with the urban industrial pollution source inventories.

  1. Improving Seasonal Precipitation Predictions over the East River Basin, South China by Using Bias-corrected CFSv2 Forecasts

    NASA Astrophysics Data System (ADS)

    Wang, D.; Zhu, C.; Wu, Y.; Lin, K.; Liu, B.; Chen, Z.; Xinjun, T.; Huang, M.

    2015-12-01

    East River is one the major tributaries of Peal River, the third largest river over China. It is the most important water resource for agriculture, industry, and commerce in the Pearl River Delta. The water demand has dramatically increased with rapid population growth and booming economic development in this region. To meet the demand of water supply, the East River basin administration has conducted the water quantity operation over the basin since 2008. However, the operation target has been hardly achieved largely due to poor precipitation predictions. We try to improve seasonal precipitation predictions by correcting the bias of the NCEP CFSv2 forecasts. A variety of bias correction methods are applied to correct CFSv2 forecasts based on a long term datasets of gauge observations and CFSv2 reforecasts. The proper bias methods are selected for the flood and the dry season respectively based on evaluation results. The CFSv2 based predictions would help in making a reasonable water quantity operation plan and improving operational performance over the East River basin.

  2. Long-Term Water and Sediment Change Detection in a Small Mountainous Tributary of the Lower Pearl River, China

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Lu, X. X.

    Hydrological regimes of river systems have been changing both qualitatively and quantitatively due to the profound human disturbances, such as river diversions, damming, and land use change. In this study, a mountainous tributary (the Luodingjiang River) of the lower Pearl River, China, was investigated to illustrate the impacts from human activities on river systems during the period 1959-2002. Mann-Kendall test and Spearman test for gradual trend and Pettitt test for abrupt change were employed to investigate the hydrological characteristics of the Luodingjiang River. Annual minimum water discharge and annual sediment yield series have significant increasing and decreasing trends, respectively, and also significant upward and downward shifts were detected by abrupt change tests, respectively, for these two data series. Neither statistically significant trends nor abrupt shift were found for annual maximum water discharge and annual mean water discharge series. The detected changes both in water and sediment point to the impacts of reservoir constructions, water diversion programs as well as land use change. However, the sediment-increasing impacts from other anthropogenic disturbances, such as road construction and mining, cannot be discerned from the recent hydrological responses.

  3. Genetoxicity of water samples from the scenic Lijang river in the Guilin area, China, evaluated by Tradescantia bioassays.

    PubMed

    Jiang, Y G; Yu, Z D; Liu, G Z; Chen, R Z; Peng, G Y

    1999-05-19

    The Lijang river which passes through the Guilin mountains, and Guilin city is a world renowned scenic spot on the southwest border of China. The river and its tributaries receive water from the mountain tops and springs underground. The river water was clean two decades ago before the development of industrial establishments and extra heavy tourism. Deforestation over the mountain tops on the upper stream and its tributaries in the last decades has created serious erosion and increased sedimentation in the river. In the present study, the Tradescantia micronucleus (Trad-MCN) and Tradescantia stamen hair mutation (Trad-SHM) assays were used to evaluate the genetoxicity of water samples collected from 60 different sites along the river. Results indicate that most of the water samples from the tributaries were highly mutagenic, and that pollutants had accumulated in the main river in the Guilin city area from the industrial effluent and city sewage. Both the Trad-MCN and Trad-SHM assays were highly effective for the detection of mutagens in the water samples.

  4. A preliminary study on the occurrence and behavior of carbamazepine (CBZ) in aquatic environment of Yangtze River Delta, China.

    PubMed

    Zhou, X F; Dai, C M; Zhang, Y L; Surampalli, R Y; Zhang, T C

    2011-02-01

    The occurrence and behavior of carbamazepine (CBZ) was investigated in aquatic environment of Yangtze River Delta, East China. The water samples were enriched by solid-phase extraction and analyzed by high-performance liquid chromatography with diode array detector. The validation of the analytical method included linearity (0.1-1 mg/L), recovery studies, and determination of limits of quantification. Limits of quantification of CBZ in various aquatic samples were in the range of 0.1-0.2 μg/L. CBZ was detected in the Tongji University Intramural River, the Huangpu River, and the Suzhou River with the highest concentration of 1,090 ng/L, but not detected in the Nanhengyin River and the Caojia River. In sewage water samples, CBZ was not detected in one of the sewage treatment plants (STPs) but was detected in the raw influents and effluents at the other three selected STPs in Shanghai, with the concentrations ranging from 230 to 1,110 ng/L. CBZ was not completely eliminated after secondary treatment (with the active sludge process).

  5. Absorption coefficient of urban aerosol in Nanjing, west Yangtze River Delta, China

    NASA Astrophysics Data System (ADS)

    Zhuang, B. L.; Wang, T. J.; Liu, J.; Ma, Y.; Yin, C. Q.; Li, S.; Xie, M.; Han, Y.; Zhu, J. L.; Yang, X. Q.; Fu, C. B.

    2015-12-01

    Absorbing aerosols can significantly modulate short-wave solar radiation in the atmosphere, affecting regional and global climate. The aerosol absorption coefficient (AAC) is an indicator that assesses the impact of absorbing aerosols on radiative forcing. In this study, the near-surface AAC and absorption Ångström exponent (AAE) in the urban area of Nanjing, China, are characterized on the basis of measurements in 2012 and 2013 using the seven-channel Aethalometer (model AE-31, Magee Scientific, USA). The AAC is estimated with direct and indirect corrections, which result in consistent temporal variations and magnitudes of AAC at 532 nm. The mean AAC at 532 nm is about 43.23 ± 28.13 M m-1 in the urban area of Nanjing, which is much lower than that in Pearl River Delta and the same as in rural areas (Lin'an) in Yangtze River Delta. The AAC in the urban area of Nanjing shows strong seasonality (diurnal variations); it is high in cold seasons (at rush hour) and low in summer (in the afternoon). It also shows synoptic and quasi-2-week cycles in response to weather systems. Its frequency distribution follows a typical log-normal pattern. The 532 nm AAC ranging from 15 to 65 M m-1 dominates, accounting for more than 72 % of the total data samples in the entire study period. Frequent high pollution episodes, such as those observed in June 2012 and in winter 2013, greatly enhanced AAC and altered its temporal variations and frequency distributions. These episodes are mostly due to local emissions and regional pollution. Air masses flowing from northern China to Nanjing can sometimes be highly polluted and lead to high AAC at the site. AAE at 660/470 nm from the Schmid correction (Schmid et al., 2006) is about 1.56, which might be more reasonable than from the Weingartner correction (Weingartner et al., 2003). Low AAEs mainly occur in summer, likely due to high relative humidity (RH) in the season. AAC increases with increasing AAE at a fixed aerosol loading. The RH

  6. Recognition of key regions for restoration of phytoplankton communities in the Huai River basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Changsen; Liu, Changming; Xia, Jun; Zhang, Yongyong; Yu, Qiang; Eamus, Derek

    2012-02-01

    SummaryHealthy phytoplankton communities are the basis of healthy water ecosystems, and form the foundation of many freshwater food webs. Globally many freshwater ecosystems are degraded because of intensive human activities, so water ecosystem restoration is a burning issue worldwide. Selection of key regions for phytoplankton-related restoration is crucial for an effective aquatic eco-restoration. This paper presents a practical method for identification of key regions for phytoplankton-related restoration, using random forests (RFs) method to cluster sites based on dominance, biodiversity, water chemistry and ecological niche. We sampled phytoplankton for species richness and relative abundance and water quality in the Huai River basin (HRB), China to determine the phytoplankton communities' composition and structure and characterize of their ecological niches. A wider mean niche breadth of a species usually leads to a greater overlap with the niche of other species. Using these data and water quality indices, we identified the key regions for phytoplankton-related river restoration activities. Results indicate that our method for recognition of key regions is effective and practical and its application to the HRB identified the Northern Plain area as the key region for restoration. This area is severely polluted and contributes significantly to the HRB phytoplankton communities. Phytoplankton in this region is highly adaptable to environmental change and therefore will be relatively unharmed by environmental instability induced by restoration measures. During restoration, indices of water temperature, total phosphorus and chemical oxygen demand can be altered with little negative influence on phytoplankton communities, but measures that increase ammonia-nitrogen concentration would be highly detrimental. These results will provide valuable information for policy makers and stakeholders in water ecosystem restoration and sustainable basin management in the HRB.

  7. Forest recovery and river discharge at the regional scale of Guangdong Province, China

    NASA Astrophysics Data System (ADS)

    Zhou, Guoyi; Wei, Xiaohua; Luo, Yan; Zhang, Mingfang; Li, Yuelin; Qiao, Yuna; Liu, Haigui; Wang, Chunlin

    2010-09-01

    Information on how large-scale forest changes affect water resources is important in China as country-wide reforestation programs are being implemented and concerns have arisen over possible water reduction. In this study, water budget analysis and statistical methods were used to assess the effects of significant forest recovery on river discharge at Guangdong Province based on 50 years of data. We used realized water yield (RWY) as a balance term between the outflows from and inflows to the province to represent the river discharge produced solely in Guangdong Province. The relationship between forest recovery and RWY was inferred after quantitatively examining other contributing variables including precipitation, potential evapotranspiration, development of impervious areas, human water consumption, and reservoir constructions. We applied time series analysis to test the statistical relationship between forest recovery and RWYs at annual, wet season, and dry season intervals. Both approaches showed that large-scale forest recovery did not cause significant water reduction over the past 50 years. This finding is contrary to the widely held perception of the trade-off relationship between carbon (reforestation) and water. There were no significant trends in precipitation or in RWY annually and in the wet season, but there was a significant increase of RWY in the dry season over the past 50 years. It is estimated that forest recovery may play a positive role in redistributing water from the wet season to the dry season and, consequently, in increasing water yield in the dry season. The implication of those research findings for future reforestation programs and water resource protection is also discussed.

  8. Lead isotopes as a tracer of Pb origin in the sediments from Beijiang River, South China.

    PubMed

    Gao, Bo; Liang, Xirong; Zhou, Huaidong; Tu, Xianglin

    2012-01-01

    Concentrations and enrichment of heavy metals were determined in sediments collected from Beijiang River, South China. The Pb isotopic compositions in these sediment samples were also employed to effectively identify metal pollution sources. According to the measured Pb concentrations, the total Pb concentrations in sediments varied from 62.1 to 1,152.5 μg/g, with an average concentration of 249.6 μg/g. The assessment by Geoaccumulation Index indicates that Pb is at the 'strongly contaminated' level, indicating that the Pb pollution was mainly due to anthropogenic inputs. The observed isotopic ratios varied from 1.174 to 1.204 for ²⁰⁶Pb/²⁰⁷Pb, 2.452 to 2.478 for ²⁰⁸Pb/²⁰⁷Pb, 18.404 to 18.937 for ²⁰⁶Pb/²⁰⁴Pb, 15.631 to 15.790 for ²⁰⁷Pb/²⁰⁴Pb, 38.455 to 39.121 for ²⁰⁸Pb/²⁰⁴Pb. The majority of these ratios are lower than those reported for natural geological sources, especially for sediments collected from a smelter. Significant correlation between Pb concentration and isotopic ratios suggested possible binary mixing of Pb. Combined with Pb concentration and enrichment levels, our results show that Pb pollution in the sediments of Beijiang River was mainly derived from anthropogenic sources. The mining activities and metal smelting processing was the main source of Pb pollution in this region.

  9. Ecology-oriented groundwater resource assessment in the Tuwei River watershed, Shaanxi Province, China

    NASA Astrophysics Data System (ADS)

    Yang, Z. Y.; Wang, W. K.; Wang, Z.; Jiang, G. H.; Li, W. L.

    2016-08-01

    In arid and semi-arid regions, a close relationship exists between groundwater and supergene eco-environmental issues such as swampiness, soil salinization, desertification, vegetation degradation, reduction of stream base flow, and disappearance of lakes and wetlands. When the maximum allowable withdrawal of groundwater (AWG) is assessed, an ecology-oriented regional groundwater resource assessment (RGRA) method should be used. In this study, a hierarchical assessment index system of the supergene eco-environment was established based on field survey data and analysis of the supergene eco-environment factors influenced by groundwater in the Tuwei River watershed, Shaanxi Province, China. The assessment system comprised 11 indices, including geomorphological type, lithology and structure of the vadose zone, depth of the water table (DWT), total dissolved solids content of groundwater, etc. Weights for all indices were calculated using an analytical hierarchy process. Then, the current eco-environmental conditions were assessed using fuzzy comprehensive evaluation (FCE). Under the imposed constraints, and using both the assessment results on the current eco-environment situation and the ecological constraint of DWT (1.5-5.0 m), the maximum AWG (0.408 × 108 m3/a or 24.29 % of the river base flow) was determined. This was achieved by combining the groundwater resource assessment with the supergene eco-environmental assessment based on FCE. If the maximum AWG is exceeded in a watershed, the eco-environment will gradually deteriorate and produce negative environmental effects. The ecology-oriented maximum AWG can be determined by the ecology-oriented RGRA method, and thus sustainable groundwater use in similar watersheds in other arid and semi-arid regions can be achieved.

  10. Transpiration and canopy conductance variations of shelterbelt in an arid inland river basin of northwest China

    NASA Astrophysics Data System (ADS)

    Gao, G.

    2015-12-01

    The knowledge of plant water use characteristics under changing environmental conditions is essential for ecosystem management and water resources distribution in water-stressed environments. This study was conducted to quantify variations in transpiration and canopy conductance in a shelterbelt in the middle of the Heihe River Basin, China. Sap flow of eight Gansu Poplar trees (Populus gansuensis) with different diameters at breast height (DBH) was measured over three consecutive growing seasons (2012-2014). The evapotranspiration of groundwater via plant use was estimated by the White method, with diurnal water table fluctuations. Results showed that mean sap flow density varied between 30.62 ±11.44 and 101.88 ±28.98 kg m-2 h-1, and it increased linearly with the DBH. Variations of sap flow density were mainly controlled by meteorological factors in addition to water table depth. Average stand transpiration during the growing season was about 4.85 mm day-1, and it had a logarithmic relationship with reference crop evapotranspiration. Precipitation increased stand transpiration, but not at a statistically significant level (p>0.05). The recharge of soil water by irrigation significantly accelerated stand transpiration (p<0.05). Stand transpiration and canopy conductance increased by 27% and 31%, respectively, when soil water conditions changed from dry to wet. Canopy conductance decreased logarithmically with vapor pressure deficit, whereas there was no apparent relationship between canopy conductance and solar radiation. The sensitivity of canopy conductance to vapor pressure deficit decreased under dry soil conditions. Groundwater evapotranspiration (0.6-7.1 mm day-1) was linearly correlated with stand transpiration (1.1-6.5 mm day-1) (R2 = 0.71). During the drought period, approximately 80% of total stand transpiration came from groundwater evapotranspiration. This study highlighted the critical role of irrigation and groundwater for shelterbelts, and might

  11. Identification of pollutant sources in a rapidly developing urban river catchment in China

    NASA Astrophysics Data System (ADS)

    Huang, Jingshui; Yin, Hailong; Jomma, Seifeddine; Rode, Michael; Zhou, Qi

    2016-04-01

    Rapid economic development and urbanization worldwide cause serious ecological and environmental problems. A typical region that is in transition and requires systemic research for effective intervention is the rapidly developing city of Hefei in central P. R. China. In order to investigate the sources of pollutants over a one-year period in Nanfei River catchment that drains the city of Hefei, discharges were measured and water samples were taken and measured along the 14km river section at 10 sites for 4 times from 2013 to 2014. Overflow concentrations of combined sewer and separate storm drains were also measured by selecting 15 rain events in 4 typical drainage systems. Loads and budgets of water and different pollutant sources i.e., wastewater treatment plant (WWTP) effluent, urban drainage overflow, unknown wastewater were calculated. The water balance demonstrated that >70% of the discharge originated from WWTP effluent. Lack of clean upstream inflow thereby is threatening ecological safety and water quality. Furthermore, mass fluxes calculations revealed that >40% of the COD (Chemical Oxygen Demand) loads were from urban drainage overflow because of a large amount of discharge of untreated wastewater in pumping stations during rain events. WWTP effluent was the predominant source of the total nitrogen loads (>60%) and ammonia loads (>45%). However, the total phosphorous loads from three different sources are similar (˜1/3). Thus, our research provided a basis for appropriate and prior mitigation strategies (state-of-art of WWTP upgrade, sewer systems modification, storm water regulation and storage capacity improvement, etc.) for different precedence-controlled pollutants with the limited infrastructure investments in these rapidly developing urban regions.

  12. Organochlorines in sediments and mussels collected from coastal sites along the Pearl River Delta, South China.

    PubMed

    Fang, Zhan-qiang

    2004-01-01

    The level and pattern of residues of organochlorine pesticide and polychlorinated biphenyls(PCBs) were analyzed in sediment and mussel (Perna viridis) samples from ten coastal sites along the Pearl River Delta, South China. The range of total HCH was < 0.01 to 0.29 ng/g freeze-dried weight in sediment, and < 0.01 to 1.35 ng/g lipid weight in mussels. Average total DDTs concentrations ranged from < 0.01 to 1.04 ng/g in sediment, and < 0.01 to 148.5 ng/g in mussels. Average total PCB concentrations ranged from 16.4 to 198.6 ng/g in sediment, and from 41 to 729.2 ng/g in mussels. Organochlorine pesticide and PCBs in mussels and sediments presented similar distribution patterns. The regression analysis indicated that PCBs concentrations in mussels were significantly correlated (p < 0.01) with concentrations in sediments. However, their concentrations in mussels were several times higher than the concentration detected in surrounding sediments. The major fraction of DDT related compounds measured in mussels and sediments was DDD. Based on average PCB concentrations, penta-, hexa-, and tetrachlorobiphenyls were preferentially accumulated by mussels as compared to the average sediment composition. According to the present results,three organochlorine polluted "hot spot" sites, including Victoria Harbour, Lingding Yang and Huangmao Sea, were found in the Pearl River estuarine zone. HCHs, DDTs and PCBs in all mussel samples were below the limits of 2, 0.2 and 5.0 microg/g wet weight recommended by the Technical Group of Guangdong Coastal Zone Resource Comprehensive Survey and U. S. Food and Drug Administration.

  13. 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

  14. 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.

  15. Mercury and methylmercury concentrations in two newly constructed reservoirs in the Wujiang River, Guizhou, China.

    PubMed

    Yao, Heng; Feng, Xinbin; Guo, Yanna; Yan, Haiyu; Fu, Xuewu; Li, Zhonggen; Meng, Bo

    2011-03-01

    We studied the distribution of different mercury species in two newly created reservoirs (Hongjiadu [HJD] and Suofengying [SFY] Reservoir) within the Wujiang River, Guizhou Province, China. These reservoirs were sampled four times between January, 2007, and November, 2007. Water, soil, and fish tissue samples were collected and analyzed for organic (methylmercury) and total Hg. Dissolved organic carbon (DOC) content in water was measured as well. In both reservoirs, the DOC concentration was low (range 0.5-4.9 mg/L). Organic matter content in soil collected near the bank of both reservoirs was also low (range 0.4-6.9%). The total MeHg level did not increase significantly with depth in water column, nor did it exhibit a pronounced spatial pattern moving from upstream to the dam. The total MeHg level did not increase significantly with depth in water column, nor did it exhibit a pronounced spatial pattern moving from upstream to the dam. The total Hg content in fish tissue was on average 0.044 mg/kg wet weight, which is a very low content in an international comparison. It is suggested that the studied reservoirs were not active sites of net Hg methylating. Low levels of organic matter (OM) may constrict the evolution of the bulk Hg methylation process occurring in flooded soil. Therefore, we hypothesize that newly constructed reservoirs in the karstic region of Southwest China appear to be much less beset by the problems of MeHg pollution that have been reported for corresponding reservoirs in North America and Europe. However, further research is required to verify this finding.

  16. Inorganic aerosols responses to emission changes in Yangtze River Delta, China

    SciTech Connect

    Dong, Xinyi; Li, Juan; Fu, Joshua S.; Gao, Yang; Huang, Kan; Zhuang, Guoshun

    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 over 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.

  17. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

    PubMed

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2016-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg(-)¹, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety. PMID:26703698

  18. Measurement and Analysis of a Multiday Photochemical Smog Episode in the Pearl River Delta of China.

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Kwok, Joey Y. H.

    2003-03-01

    Recent measurements of a photochemical episode in September of 2001 in the Pearl River delta (PRD) were analyzed to gain insight into the meteorological and chemical processes affecting ozone (O3) concentrations in the subtropical southern China coast. High concentrations (>120 ppbv) of O3 were observed at a rural coastal site in western Hong Kong for six consecutive days, with maximum 1-h O3 concentration reaching 191 ppbv and visibility decreasing to 1.8 km. Comparison with O3 data obtained from six other sites in the region indicated the regional nature of the O3 pollution. Examination of synoptic charts showed that this unusually severe and prolonged pollution episode was induced by a quasi-stationary tropical cyclone in the East China Sea that caused air subsidence and stagnation over the PRD. Weak northerly winds were observed from radiosonde and at a mountaintop site, but surface winds showed a complex pattern owing to land-sea breezes and the topography effects. The measurements of O3, carbon monoxide (CO), sulfur dioxide (SO2), nitric oxide (NO), and total reactive nitrogen (NOy) at the western Hong Kong site were analyzed to show the possible sources and emission characteristics of O3-laden plumes. The daytime high concentrations of O3 and other pollutants were caused by the diffusion/advection of urban plumes under light north-northeast winds; and their reduced concentrations in the late afternoon were due to the stronger sea breezes. The large values of CO/NOy and SO2/NOy on some days implied the contribution of regional emissions to the high O3 in western Hong Kong. The data from the western site were compared with those from an eastern site to illustrate the spatial variability of air pollutants in the coastal environment of the study region.

  19. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    PubMed Central

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety. PMID:26703698

  20. Heavy metals in agricultural soils of the Pearl River Delta, South China.

    PubMed

    Wong, S C; Li, X D; Zhang, G; Qi, S H; Min, Y S

    2002-01-01

    There is a growing public concern over the potential accumulation of heavy metals in agricultural soils in China owing to rapid urban and industrial development and increasing reliance on agrochemicals in the last several decades. Excessive accumulation of heavy metals in agricultural soils may not only result in environmental contamination, but elevated heavy metal uptake by crops may also affect food quality and safety. The present study is aimed at studying heavy metal concentrations of crop, paddy and natural soils in the Pearl River Delta, one of the most developed regions in China. In addition, some selected soil samples were analyzed for chemical partitioning of Co, Cu, Pb and Zn. The Pb isotopic composition of the extracted solutions was also determined. The analytical results indicated that the crop, paddy and natural soils in many sampling sites were enriched with Cd and Pb. Furthermore, heavy metal enrichment was most significant in the crop soils, which might be attributed to the use of agrochemicals. Flooding of the paddy soils and subsequent dissolution of Mn oxides may cause the loss of Cd and Co through leaching and percolation, resulting in low Cd and Co concentrations of the paddy soils. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the Fe-Mn oxide and residual fractions, while Zn was predominantly found in the residual phase. A significant percent fraction of Cu was bound in the organic/sulphide and residual phases. Based on the 206Pb/207Pb ratios of the five fractions, it was evident that some of the soils were enriched with anthropogenic Pb, such as industrial and automobile Pb. The strong associations between anthropogenic Pb and the Fe-Mn oxide and organic/sulphide phases suggested that anthropogenic Pb was relatively stable after deposition in soils. PMID:12125727

  1. Aerosol optical properties and mixing state of black carbon in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Tan, Haobo; Liu, Li; Fan, Shaojia; Li, Fei; Yin, Yan; Cai, Mingfu; Chan, P. W.

    2016-04-01

    Aerosols contribute the largest uncertainty to the total radiative forcing estimate, and black carbon (BC) that absorbs solar radiation plays an important role in the Earth's energy budget. This study analysed the aerosol optical properties from 22 February to 18 March 2014 at the China Meteorological Administration Atmospheric Watch Network (CAWNET) station in the Pearl River Delta (PRD), China. The representative values of dry-state particle scattering coefficient (σsp), hemispheric backscattering coefficient (σhbsp), absorption coefficient (σabsp), extinction coefficient (σep), hemispheric backscattering fraction (HBF), single scattering albedo (SSA), as well as scattering Ångström exponent (α) were presented. A comparison between a polluted day and a clean day shows that the aerosol optical properties depend on particle number size distribution, weather conditions and evolution of the mixing layer. To investigate the mixing state of BC at the surface, an optical closure study of HBF between measurements and calculations based on a modified Mie model was employed for dry particles. The result shows that the mixing state of BC might be between the external mixture and the core-shell mixture. The average retrieved ratio of the externally mixed BC to the total BC mass concentration (rext-BC) was 0.58 ± 0.12, and the diurnal pattern of rext-BC can be found. Furthermore, considering that non-light-absorbing particles measured by a Volatility-Tandem Differential Mobility Analyser (V-TDMA) exist independently with core-shell and homogenously internally mixed BC particles, the calculated optical properties were just slightly different from those based on the assumption that BC exist in each particle. This would help understand the influence of the BC mixing state on aerosol optical properties and radiation budget in the PRD.

  2. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

    PubMed

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-12-22

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg(-)¹, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  3. Dynamic Monitoring of Soil and Water Losses Using Remote Sensing and GIS Techniques: a Case Study of Jialing River, Yangtze River, China

    NASA Astrophysics Data System (ADS)

    Li, C.; Zhu, Y. J.; Li, G. E.; Zhu, Y. Q.; Li, R. H.; Wang, L.; Wu, Y. J.

    2016-06-01

    Water and soil loss problems are serious in China, especially in the upper and middle reaches of big rivers. This paper dynamically observed water and soil loss in key control regions in Jialing River Basin. Based on remotely sensed images, the method used in this paper is a combination of field investigation and indoor artificial interpretation under the technologies of RS and GIS. The method was proven to be effective of improving the accuracy of interpreting. The result shows the land use types of the researched regions and how they changed among the previous years. Evaluation of water and soil conservation was made. This result can provide references for further policy-making and water and soil loss controlling.

  4. 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. PMID:24292872

  5. 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.

  6. Relation between oceanic conditions in the South China Sea and water levels within and along the Vietnamese Mekong River Delta

    NASA Astrophysics Data System (ADS)

    Uehara, K.; Tanaka, A.; Saito, Y.; Tamura, T.; Nguyen, V. L.; Ta, T. K.

    2013-12-01

    Seasonal water level change within and around the Vietnamese Mekong River Delta (MRD) has been analyzed to understand the impact of climate change in the South China Sea on river flooding within the MRD. It was found that the sea level variability along the deltaic coast has high coherence with the strength of offshore oceanic currents which seasonally reverse their direction under the SE Asian monsoon climate, indicating that the coastal sea level is linked with offshore currents through a geostrophic relation. It was also suggested that the temporal pattern of water levels in the middle reaches of the MRD, 80-100km apart from the river mouth, was influenced not only by upstream information but also by the downstream sea level change. These results indicates that the climatic change in the oceanic current field may influence the occurrence of flooding within the MRD especially during the NE monsoon season when the sea level is high.

  7. River-derived sediment suspension and transport in the Bohai, Yellow, and East China Seas: A preliminary modeling study

    NASA Astrophysics Data System (ADS)

    Zeng, Xiangming; He, Ruoying; Xue, Zuo; Wang, Houjie; Wang, Yue; Yao, Zhigang; Guan, Weibing; Warrillow, Jennifer

    2015-12-01

    Coastal circulation and transport of sediment derived from the Huanghe and Changjiang Rivers in the Bohai, Yellow, and East China Seas (BYECS) over the past 48 years (1958-2005) were simulated and analyzed using the Coupled Ocean-Atmosphere-Wave-Sediment Transport modeling system. Model skill assessments against in situ wave and hydrographical observations indicate the model simulation can reasonably well reproduce the hydrodynamic environment of the BYECS. Model-simulated regions of high fine sediment accumulation rate correlate well with the observed regions, which are known as "muddy patches." Bottom stress analysis further indicates that the formation of muddy patches near river mouths is largely due to their proximity to the sediment source. Muddy patches formed in regions farther away from river mouths are results of local weak bottom stress and associated circulation pattern. Simulated seabed sediment distribution reveals that most of the Huanghe-derived sediment stays inside the Bohai Sea, whereas the Changjiang-derived sediment can spread into both the Yellow and East China Seas. Strong seasonal variations exist in the river-derived sediment transport with stronger (weaker) offshore sediment transport occurring in the winter (summer).

  8. Early Mixed Farming of Millet and Rice 7800 Years Ago in the Middle Yellow River Region, China

    PubMed Central

    Zhang, Jianping; Lu, Houyuan; Gu, Wanfa; Wu, Naiqin; Zhou, Kunshu; Hu, Yayi; Xin, Yingjun; Wang, Can

    2012-01-01

    The Peiligang Culture (9000-7000 cal. yr BP) in the Middle Yellow River region, North China, has long been considered representative of millet farming. It is still unclear, however, if broomcorn millet or foxtail millet was the first species domesticated during the Peiligang Culture. Furthermore, it is also unknown whether millet was cultivated singly or together with rice at the same period. In this study, phytolith analysis of samples from the Tanghu archaeological site reveals early crop information in the Middle Yellow River region, China. Our results show that broomcorn millet was the early dry farming species in the Peiligang Culture at 7800 cal. yr BP, while rice cultivation took place from 7800 to 4500 cal. yr BP. Our data provide new evidence of broomcorn millet and rice mixed farming at 7800 cal. yr BP in the Middle Yellow River region, which has implications for understanding the domestication process of the two crops, and the formation and continuance of the Ancient Yellow River Civilization. PMID:23284907

  9. Holocene climatic events recorded in palaeoflood slackwater deposits along the middle Yiluohe River valley, middle Yellow River basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Xueru; Huang, Chun Chang; Pang, Jiangli; Zha, Xiaochun; Guo, Yongqiang; Hu, Guiming

    2016-06-01

    Palaeohydrological investigations were carried out in the middle reaches of the Yiluohe River, a major tributary in the lower-middle Yellow River basin. Typical palaeoflood slackwater deposits (SWDs) were identified in the Holocene pedostratigraphy on the cliffy river banks. Analytical results, including magnetic susceptibility and grain-size distribution data, indicated that these SWDs were deposited from the suspended sediment load in flood water. These SWDs are different from eolian loess, soils and aeolian sands in the riverbank profile. They recorded several episodes of extraordinary palaeoflood events. In the Longmenxia reaches of the Yihe River valley, these flood events were dated at 3100-3000 a, 1800-1700 a, 770-610 a, and 420-340 a using the optically stimulated luminescence method in combination with the pedostratigraphic correlations. In the Longhutan reaches of the Luohe River valley, the palaeoflood events were dated at 1975-1466 a, i.e., from the Han to Wei dynasties (AD 25-534), during which the capital city on the river banks was flooded many times, as recorded in the literature. These extraordinary flood events are well correlated chronologically with the known Holocene climatic events that occurred in the Northern Hemisphere. Thus, the monsoonal climate was highly variable with both floods and droughts occurring frequently during these episodes. These results are important for understanding the response of river systems in eastern Asia to global changes.

  10. 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.

  11. The evolution of the Shiwanghe River valley in response to the Yellow River incision in the Hukou area, Shaanxi, China

    NASA Astrophysics Data System (ADS)

    Qiu, Wei-Li; Zhang, Jia-Fu; Wang, Xiao-Yan; Guo, Yu-Jie; Zhuang, Mao-Guo; Fu, Xiao; Zhou, Li-Ping

    2014-06-01

    Tributary response to mainstream incision is an important landscape evolution process. The objective of this study is to examine tributary valley evolution in response to mainstream incision. The Shiwanghe River, a tributary of the Yellow River in the Hukou area, was chosen for a case study. The terraces and knickpoints of the Shiwanghe River were investigated and correlated to those of the mainstream. Optically stimulated luminescence (OSL) was applied to date fluvial terraces. Longitudinal profiles of river and terraces were used to analyze valley evolution. The terrace sequence of the Shiwanghe River near their confluence is almost identical to the Yellow River terraces at the Hukou area. This suggests that terrace formations of the tributary and the mainstream are synchronous, and influenced by similar factors. But the formation age of the same tributary terrace varies from downstream to the upper reaches of the river valley. For such terraces, their formation should be controlled by knickpoint migration. A sudden drop in base-level caused by the Yellow River incision would trigger the formation of a knickpoint in the tributary. A new terrace would be formed as the knickpoint propagated upstream throughout the tributary valley. Due to the different erodibility of bedrock, a set of interbedded sandstone and shale, the major knickpoint would disassemble into a cluster of small ones during its propagation. The age of terrace formation with various valley segments depends on knickpoint migration rate and distance from the confluence. Vertical incision of the Yellow River results in knickpoint recession of its tributaries. The migration rate of knickpoints was affected by climate, lithologic variation, and, to some extent, structural control.

  12. Oxygenated, nitrated, methyl and parent polycyclic aromatic hydrocarbons in rivers of Haihe River System, China: occurrence, possible formation, and source and fate in a water-shortage area.

    PubMed

    Qiao, Meng; Qi, Weixiao; Liu, Huijuan; Qu, Jiuhui

    2014-05-15

    Substituted polycyclic aromatic hydrocarbons (SPAHs) occur ubiquitously in the whole global environment as a result of their persistence and widely-spread sources. Some SPAHs show higher toxicities and levels than the corresponding PAHs. Three types of most frequently existing SPAHs, oxygenated-PAHs (OPAHs), nitrated-PAHs (NPAHs), and methyl-PAHs (MPAHs), as well as the 16 priority PAHs were investigated in this study. The purpose was to identify the occurrence, possible transformation, and source and fate of these target compounds in a water shortage area of North China. We took a river system in the water-shortage area in China, the Haihe River System (HRS), as a typical case. The rivers are used for irrigating the farmland in the North of China, which probably introduce these pollutants to the farmland of this area. The MPAHs (0.02-0.40 μg/L in dissolved phase; 0.32-16.54 μg/g in particulate phase), OPAHs (0.06-0.19 μg/L; 0.41-17.98 μg/g), and PAHs (0.16-1.20 μg/L; 1.56-79.38 μg/g) were found in the water samples, but no NPAHs were detected. The concentrations of OPAHs were higher than that of the corresponding PAHs. Seasonal comparison results indicated that the OPAHs, such as anthraquinone and 2-methylanthraquinone, were possibly transformed from the PAHs, particularly at higher temperature. Wastewater treatment plant (WWTP) effluent was deemed to be the major source for the MPAHs (contributing 62.3% and 87.6% to the receiving river in the two seasons), PAHs (68.5% and 89.4%), and especially OPAHs (80.3% and 93.2%) in the rivers. Additionally, the majority of MPAHs (12.4 kg, 80.0% of the total input), OPAHs (16.2 kg, 83.5%), and PAHs (65.9 kg, 93.3%) in the studied months entered the farmland through irrigation.

  13. Oxygenated, nitrated, methyl and parent polycyclic aromatic hydrocarbons in rivers of Haihe River System, China: occurrence, possible formation, and source and fate in a water-shortage area.

    PubMed

    Qiao, Meng; Qi, Weixiao; Liu, Huijuan; Qu, Jiuhui

    2014-05-15

    Substituted polycyclic aromatic hydrocarbons (SPAHs) occur ubiquitously in the whole global environment as a result of their persistence and widely-spread sources. Some SPAHs show higher toxicities and levels than the corresponding PAHs. Three types of most frequently existing SPAHs, oxygenated-PAHs (OPAHs), nitrated-PAHs (NPAHs), and methyl-PAHs (MPAHs), as well as the 16 priority PAHs were investigated in this study. The purpose was to identify the occurrence, possible transformation, and source and fate of these target compounds in a water shortage area of North China. We took a river system in the water-shortage area in China, the Haihe River System (HRS), as a typical case. The rivers are used for irrigating the farmland in the North of China, which probably introduce these pollutants to the farmland of this area. The MPAHs (0.02-0.40 μg/L in dissolved phase; 0.32-16.54 μg/g in particulate phase), OPAHs (0.06-0.19 μg/L; 0.41-17.98 μg/g), and PAHs (0.16-1.20 μg/L; 1.56-79.38 μg/g) were found in the water samples, but no NPAHs were detected. The concentrations of OPAHs were higher than that of the corresponding PAHs. Seasonal comparison results indicated that the OPAHs, such as anthraquinone and 2-methylanthraquinone, were possibly transformed from the PAHs, particularly at higher temperature. Wastewater treatment plant (WWTP) effluent was deemed to be the major source for the MPAHs (contributing 62.3% and 87.6% to the receiving river in the two seasons), PAHs (68.5% and 89.4%), and especially OPAHs (80.3% and 93.2%) in the rivers. Additionally, the majority of MPAHs (12.4 kg, 80.0% of the total input), OPAHs (16.2 kg, 83.5%), and PAHs (65.9 kg, 93.3%) in the studied months entered the farmland through irrigation. PMID:24598148

  14. Relations Between Grace-Derived Water Storage Change with Precipitation and Temperature Over Kaidu River Basin, China

    NASA Astrophysics Data System (ADS)

    Huang, J.; Zhou, Q.

    2016-06-01

    Water is essential for human survival and well-being, and important to virtually all sectors of the economy. In the aridzone of China's west, water resource is the controlling factor on the distribution of human settlements. Water cycle variation is sensitive to temperature and precipitation, which are influenced by human activity and climate change. Satellite observations of Earth's time-variable gravity field from the Gravity Recovery and Climate Experiment (GRACE) mission, which enable direct measurement of changes of total terrestrial water storage, could be useful to aid this modelling. In this pilot study, TWS change from 2002 to 2013 obtained from GRACE satellite mission over the Kaidu River Basin in Xinjiang, China is presented. Precipitation and temperature data from in-situ station and National Satellite Meteorological Centre of China (NSMC) are analysed to examine whether there is a statistically significant correlation between them.

  15. 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.

  16. Spatial patterns and variations of suspended sediment transport in the upper- and mid-stream Yarlung Tsangpo River, China

    NASA Astrophysics Data System (ADS)

    Shi, Xiaonan; Zhang, Fan

    2016-04-01

    The Yarlung Tsangpo River (YL River), flowing from west to east across the southern section of the Tibetan Plateau, is the longest river and as well an important activity center for Tibet Autonomous Region of China. The suspended sediment in the river is an important proxy for regional erosional severity and ecological environment. However, the sediment transport in the river is rarely reported under data scarcity due to the harsh climate conditions, high elevation, and intensive area. Under the interaction of monsoon climate and topography variability, what are the spatial patterns and variations of the suspended sediment in the YL River and how to explain the spatial pattern and variation? Based on the analysis of monthly discharge and suspended sediment concentration data from four mainstream stations, spatial patterns and variations of suspended sediment in the upper- and mid-stream YL River are studied. The results of spatial distribution analysis show that high erosion intensity occurred in the upper area of the mid-stream reaches while there is a large deposition area located at the end of middle stream. On the whole, the annual sediment yield transported at the end of mid-stream is 1043 *104 t with average specific sediment yield of 54.4 t/km2/yr which illustrates that the sediment contribution is at a relative low level from the upper- and mid-stream YL River. The sediment transport mainly occurs in the three months of Jul. to Sep., as just the time of rainy season, flood season, and intensive melting time period of glaciers, accounting for 79%~93% of the annual gross yield (more concentrated for upstream). Finally, the spatial variations of suspended sediment are comprehensively analyzed and explained in terms of the sediment rating curve, climate, hydrology, and riverbed morphology characteristics.

  17. Source apportionment and health effect of NOx over the Pearl River Delta region in southern China.

    PubMed

    Lu, Xingcheng; Yao, Teng; Li, Ying; Fung, Jimmy C H; Lau, Alexis K H

    2016-05-01

    As one of the most notorious atmospheric pollutants, NOx not only promotes the formation of ozone but also has adverse health effects on humans. It is therefore of great importance to study the sources of NOx and its effects on human health. The Comprehensive Air Quality Model (CAMx) modeling system and ozone source apportionment technology (OSAT) were used to study the contribution of NOx from different emission sources over southern China. The results indicate that heavy duty diesel vehicles (HDDVs) and industrial point sources are the two major local NOx sources, accounting for 30.8% and 18.5% of local NOx sources, respectively. In Hong Kong, marine emissions contributed around 43.4% of local NOx in 2011. Regional transport is another important source of this pollutant, especially in February and November, and it can contribute over 30% of ambient NOx on average. Power plant point emission is an significant regional source in Zhuhai, Zhongshan and Foshan. The total emission sources are estimated to cause 2119 (0-4405) respiratory deaths and 991 (0-2281) lung cancer deaths due to long-term exposure to NOx in the Pearl River Delta region. Our results suggest that local governments should combine their efforts and vigorously promote further reduction of NOx emissions, especially for those sources that make a substantial contribution to NOx emissions and affect human health: HDDV, LDGV, industrial point sources and marine sources.

  18. VOCs and OVOCs distribution and control policy implications in Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Louie, Peter K. K.; Ho, Josephine W. K.; Tsang, Roy C. W.; Blake, Donald R.; Lau, Alexis K. H.; Yu, Jian Zhen; Yuan, Zibing; Wang, Xinming; Shao, Min; Zhong, Liuju

    2013-09-01

    Ambient air measurements of volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs) were conducted and characterised during a two-year grid study in the Pearl River Delta (PRD) region of southern China. The present grid study pioneered the systematic investigation of the nature and characteristics of complex VOC and OVOC sources at a regional scale. The largest contributing VOCs, accounting over 80% of the total VOCs mixing ratio, were toluene, ethane, ethyne, propane, ethene, butane, benzene, pentane, ethylbenzene, and xylenes. Sub-regional VOC spatial characteristics were identified, namely: i) relatively fresh pollutants, consistent with elevated vehicular and industrial activities, around the PRD estuary; and ii) a concentration gradient with higher mixing ratios of VOCs in the west as compared with the eastern part of PRD. Based on alkyl nitrate aging determination, a high hydroxyl radical (OH) concentration favoured fast hydrocarbon reactions and formation of locally produced ozone. The photochemical reactivity analysis showed aromatic hydrocarbons and alkenes together consisted of around 80% of the ozone formation potential (OFP) among the key VOCs. We also found that the OFP from OVOCs should not be neglected since their OFP contribution was more than one-third of that from VOCs alone. These findings support the choice of current air pollution control policy which focuses on vehicular sources but warrants further controls. Industrial emissions and VOCs emitted by solvents should be the next targets for ground-level ozone abatement.

  19. Seasonality in polybrominated diphenyl ether concentrations in the atmosphere of the Yangtze River Delta, China.

    PubMed

    Zhang, Lifei; Dong, Liang; Huang, Yeru; Shi, Shuangxin; Yang, Wenlong; Zhou, Li

    2016-05-01

    Polybrominated diphenyl ether (PBDE) concentrations in the atmosphere in rapidly developing parts of China have been studied little. In this study, polyurethane foam disk passive air samplers were used to comprehensively investigate PBDE concentrations in the atmosphere of the Yangtze River Delta in different seasons in 2010 and 2011. The mean sum of the concentrations of 13 PBDE congeners was 3.3 pg/m(3) in spring, 7.3 pg/m(3) in summer, 1.0 pg/m(3) in autumn, and 12 pg/m(3) in winter. Higher PBDE concentrations were found in urban areas than in rural areas. The PBDE concentrations were comparable to concentrations that have been found in cities around the world. BDE28, BDE47, BDE99, BDE153, and BDE183 were the dominant PBDE congeners in all seasons. High PBDE concentrations were found in satellite cities, such as Changshu, Wujiang, and Zhangjiagang, suggesting that commercial PBDEs (including pentabromodiphenyl ether products) are produced and/or used in those cities. The PBDE concentrations in the atmosphere were used to estimate daily doses through the inhalation of outdoor air. The most severe risks posed by exposure to PBDEs were found to occur in winter, for both adults and children, but the PBDE concentrations were found not to pose appreciable risks to human health. PMID:26791420

  20. Regional dynamics of persistent organic pollutants (POPs) in the Pearl River Delta, China: implications and perspectives.

    PubMed

    Zhang, Kai; Zhang, Bao-Zhong; Li, Shao-Meng; Zeng, Eddy Y

    2011-10-01

    The mass transport budgets of 1,1,1-trichloro-2,2-bis(chlorophenyl)ethane (p,p'-DDT) and decabromodiphenyl ether (BDE-209) in the Pearl River Delta, South China were calculated based on previously collected data. Residual p,p'-DDT, mostly related to historical use, has largely settled into soil (780,000 kg), while the soil BDE-209 inventory (44,000 kg) is considerably smaller. Conversely, large amounts of BDE-209 currently used in numerous commercial products have resulted in a much higher atmospheric depositional flux of BDE-209 (28,100 kg/yr) relative to p,p'-DDT (310 kg/yr). The soil inventory of p,p'-DDT is predicted to decrease to half of its current value after 22 years, and the percent area containing soil p,p'-DDT at levels exceeding the effects range-medium (27 ng/g) will decrease from 40% to 20%. Finally, soil BDE-209 inventory will reach an equilibrium value of 940 tons in ~60 years, when BDE-209 levels in 50% of soil will be above an equivalent risk guideline value (125 ng/g). PMID:21669481

  1. Changes in daily and monthly rainfall in the Middle Yellow River, China

    NASA Astrophysics Data System (ADS)

    He, Yi; Tian, Peng; Mu, Xingmin; Gao, Peng; Zhao, Guangju; Wang, Fei; Li, Pengfei

    2016-03-01

    Highly concentrated precipitation, where a large percentage of annual precipitation occurs over a few days, may include a high risk of flooding and severe soil erosion. Thus, areas with severe erosion such as the Loess Plateau in China are particularly vulnerable to highly concentrated precipitation events due to climate change. In this study, we investigated spatial and temporal patterns in the concentration of rainfall in the Middle Yellow River (MYR) from the last 56 years (1958-2013). We used daily and monthly precipitation data from 26 meteorological stations in the study area to calculate the precipitation concentration index (PCI) and the concentration index (CI). The southern and northern parts of the MYR were characterized by a lower CI with a decreasing trend, while the middle parts had a higher CI with an increasing trend. High PCI values occurred in the southern MYR, while lower PCIs with a more homogenous rainfall distribution were found mainly in the northern parts of the MYR. The annual PCI and CI exhibited positive trends at most stations, although only a minority of stations had significant trends (P < 0.05). At seasonal scales, CI exhibited significantly increasing trends in winter at most stations, while a few stations had significant trends in the other three seasons. These findings provide important reference information to facilitate ecological restoration and farming operations in the study region.

  2. Regional contribution to PM1 pollution during winter haze in Yangtze River Delta, China.

    PubMed

    Tang, Lili; Yu, Hongxia; Ding, Aijun; Zhang, Yunjiang; Qin, Wei; Wang, Zhuang; Chen, Wentai; Hua, Yan; Yang, Xiaoxiao

    2016-01-15

    To quantify regional sources contributing to submicron particulate matter (PM1) pollution in haze episodes, on-line measurements combining two modeling methods, namely, positive matrix factorization (PMF) and backward Lagrangian particle dispersion modeling (LPDM), were conducted for the period of one month in urban Nanjing, a city located in the western part of Yangtze River Delta (YRD) region of China. Several multi-day haze episodes were observed in December 2013. Long-range transport of biomass burning from the southwestern YRD region largely contributed to PM1 pollution with more than 25% of total organics mass in a lasting heavy haze. The LPDM analysis indicates that regional transport is a main source contributing to secondary low-volatility production. The high-potential source regions of secondary low-volatility production are mainly located in areas to the northeast of the city. High aerosol pollution was mainly contributed by regional transport associated with northeastern air masses. Such regional transport on average accounts for 46% of total NR-PM1 with sulfate and aged low-volatility organics being the largest fractions (>65%).

  3. Ancient landslide-dam events in the Jishi Gorge, upper Yellow River valley, China

    NASA Astrophysics Data System (ADS)

    Dong, Guanghui; Zhang, Fanyu; Ma, Minmin; Fan, Yuxin; Zhang, Jiawu; Wang, Zongli; Chen, Fahu

    2014-05-01

    Some scholars have argued that the formation and outburst of an ancient dammed lake in the Jishi Gorge at ca. 3700 cal yr BP resulted in the destruction of Lajia, the site of a famous prehistoric disaster in the Guanting Basin, upper Yellow River valley, China. However, the cause of the dammed lake and the exact age of the dam breaching are still debated. We investigated ancient landslides and evidence for the dammed lake in the Jishi Gorge, including dating of soil from the shear zone of an ancient landslide, sediments of the ancient dammed lake, and loess above lacustrine sediments using radiocarbon and optically stimulated luminescence (OSL) dating methods. Six radiocarbon dates and two OSL dates suggested that the ancient landslides and dammed lake events in the Jishi Gorge probably occurred around 8100 cal yr BP, and the ancient dammed lake was breached between 6780 cal yr BP and 5750 cal yr BP. Hence, the outburst of the ancient dammed lake in the Jishi Gorge was unrelated to the ruin of the Lajia site, but likely resulted in flood disasters in the Guanting Basin around 6500 cal yr BP.

  4. Influence of climate factors on Vibrio cholerae dynamics in the Pearl River estuary, South China.

    PubMed

    Yue, Yujuan; Gong, Jianhua; Wang, Duochun; Kan, Biao; Li, Baisheng; Ke, Changwen

    2014-06-01

    Current research has seldom focused on the quantitative relationships between Vibrio cholerae (V. cholerae) and climate factors owing to the complexities and high cost of field observation in the aquatic environment. This study has focused on the relationships between V. cholerae and climate factors based on linear regression method and data partition method. Data gathered from 2008 to 2009 in the Pearl River estuary, South China, were adopted. Positive rate of V. cholerae was correlated closely with monthly climate factors of water temperature and air temperature, respectively in 2009. Quarterly data analysis from 2008 to 2009 showed that there existed seasonal characteristic for V. cholerae. Positive rate of V. cholerae was correlated positively with quarterly climate factors of land surface temperature, pH, water temperature, air temperature and rainfall, respectively and negatively with quarterly air pressure. Partition data analysis in 2009 showed that there existed geography region characteristic for V. cholerae. V. cholerae dynamics was closely correlated to climate factors in the downstream area. However, it was more greatly affected by human geography factors in the urban area. Positive annual rate of V. cholerae was higher in the downstream area than in the urban area both in 2008 and 2009. At last, a cellular automaton model was used to simulate V. cholerae diffusion downstream, and the distribution of V. cholerae obtained from this model was similar to that obtained from the field observations.

  5. Metagenomic Analysis of Virioplankton of the Subtropical Jiulong River Estuary, China

    PubMed Central

    Cai, Lanlan; Zhang, Rui; He, Ying; Feng, Xiaoyuan; Jiao, Nianzhi

    2016-01-01

    Viruses are the most abundant biological entities in the oceans, and encompass a significant reservoir of genetic diversity. However, little is known about their biodiversity in estuary environments, which represent a highly dynamic and potentially more diverse habitat. Here, we report a metagenomic analysis of the dsDNA viral community from the Jiulong River Estuary (JRE), China, and provide a comparative analysis with other closely related environments. The results showed that the majority of JRE virome did not show any significant similarity to the database. For the major viral group (Caudovirales) detected in the sample, Podoviridae (44.88%) were the most abundant family, followed by Siphoviridae (32.98%) and Myoviridae (17.32%). The two most abundant viruses identified in the virome were phages HTVC010P and HMO-2011, which infect bacteria belonging to marine SAR11 and SAR116 clades, respectively. Two contigs larger than 20 kb, which show similar overall genome architectures to Celeribacter phage P12053L and Thalosomonas phage BA3, respectively, were generated during assembly. Comparative analysis showed that the JRE virome was more similar to marine viromes than to freshwater viromes, and shared a relative coarse-grain genetic overlap (averaging 14.14% ± 1.68%) with other coastal viromes. Our study indicated that the diversity and community structure of the virioplankton found in JRE were mainly affected by marine waters, with less influence from freshwater discharge. PMID:26848678

  6. [Environmental benefit-loss analysis of agro-ecosystem in Haihe River Basin, China].

    PubMed

    Bai, Yang; Ouyang, Zhi-yun; Zheng, Hua; Xu, Wei-hua; Jiang, Bo; Fang, Yu

    2010-11-01

    According to the connotation of ecosystem services, an evaluation index system for the agro-ecosystem services in the Haihe River basin of China was established, and the economic value of the agro-ecosystem services and environmental costs were evaluated by the methods of market valuation, shadow price, and opportunity cost. In 2005, the total environmental benefit value of the agro-ecosystem services in the basin was 180. 264 billion RMB, with the regulation value of 79.416 billion RMB (44.06%) and the supporting value of 100.848 billion RMB (55.94%). Provision and cultural services were not considered in this research. From the viewpoint of functional type, the ecosystem services value from high to low was in the order of oxygen release > water conservation > nutrient cycling > soil conservation > waste purification > environmental purification > carbon sequestration > straw returning. The environmental costs of the agro-ecosystem were quite high (42. 293 billion RMB), among which, fertilizer loss was 427.42 x 10(4) t, equivalent to 15.191 billion RMB, and greenhouse gases production was calculated as 3599.65 x 10(4) t CO2, equivalent to 27. 102 billion RMB.

  7. Regional contribution to PM1 pollution during winter haze in Yangtze River Delta, China.

    PubMed

    Tang, Lili; Yu, Hongxia; Ding, Aijun; Zhang, Yunjiang; Qin, Wei; Wang, Zhuang; Chen, Wentai; Hua, Yan; Yang, Xiaoxiao

    2016-01-15

    To quantify regional sources contributing to submicron particulate matter (PM1) pollution in haze episodes, on-line measurements combining two modeling methods, namely, positive matrix factorization (PMF) and backward Lagrangian particle dispersion modeling (LPDM), were conducted for the period of one month in urban Nanjing, a city located in the western part of Yangtze River Delta (YRD) region of China. Several multi-day haze episodes were observed in December 2013. Long-range transport of biomass burning from the southwestern YRD region largely contributed to PM1 pollution with more than 25% of total organics mass in a lasting heavy haze. The LPDM analysis indicates that regional transport is a main source contributing to secondary low-volatility production. The high-potential source regions of secondary low-volatility production are mainly located in areas to the northeast of the city. High aerosol pollution was mainly contributed by regional transport associated with northeastern air masses. Such regional transport on average accounts for 46% of total NR-PM1 with sulfate and aged low-volatility organics being the largest fractions (>65%). PMID:26414850

  8. Floristic characteristics and biodiversity patterns in the Baishuijiang River basin, China.

    PubMed

    Liu, Bing; Zhao, Wenzhi; Wen, Zijuan; Teng, Jirong; Li, Xiaohong

    2009-07-01

    A case study was conducted on the forest ecosystem in the Baishuijiang River basin of China to reveal the influences of environmental factors and human disturbance on the floristic characteristics and biodiversity patterns. Field surveys of the floristic composition, environmental factors, and disturbance factors were conducted along an elevation gradient, and the relationships between biodiversity pattern and environmental factors were analyzed using CCA (canonical correspondence analysis). The results showed that the floristic composition of higher plants consisted of 197 families, 796 genera, 2165 species, 19 subspecies, 239 varietas, and 12 forma, and it was characterized by the multi-geographic composition and by the transition from tropical to temperate zones. Along an elevation gradient, the variations in alpha and beta diversity were best described by a bimodal curve, and the peak values occurred at middle elevations. The CCA indicated that the elevation had the greatest influence on the biodiversity pattern, followed by the topographic index, slope direction, slope, slope position, slope shape, and vegetation coverage. In addition, human disturbance has greatly impacted the floristic composition and biodiversity patterns, and the biodiversity indices were higher with intermediate disturbance at middle elevations compared to higher and lower disturbances at low and high elevations, respectively. This reflected a disturbance-diversity pattern and thus revealed the obvious importance to maintain the intermediate disturbance for biodiversity conservation. PMID:19452203

  9. Floristic characteristics and biodiversity patterns in the Baishuijiang River basin, China.

    PubMed

    Liu, Bing; Zhao, Wenzhi; Wen, Zijuan; Teng, Jirong; Li, Xiaohong

    2009-07-01

    A case study was conducted on the forest ecosystem in the Baishuijiang River basin of China to reveal the influences of environmental factors and human disturbance on the floristic characteristics and biodiversity patterns. Field surveys of the floristic composition, environmental factors, and disturbance factors were conducted along an elevation gradient, and the relationships between biodiversity pattern and environmental factors were analyzed using CCA (canonical correspondence analysis). The results showed that the floristic composition of higher plants consisted of 197 families, 796 genera, 2165 species, 19 subspecies, 239 varietas, and 12 forma, and it was characterized by the multi-geographic composition and by the transition from tropical to temperate zones. Along an elevation gradient, the variations in alpha and beta diversity were best described by a bimodal curve, and the peak values occurred at middle elevations. The CCA indicated that the elevation had the greatest influence on the biodiversity pattern, followed by the topographic index, slope direction, slope, slope position, slope shape, and vegetation coverage. In addition, human disturbance has greatly impacted the floristic composition and biodiversity patterns, and the biodiversity indices were higher with intermediate disturbance at middle elevations compared to higher and lower disturbances at low and high elevations, respectively. This reflected a disturbance-diversity pattern and thus revealed the obvious importance to maintain the intermediate disturbance for biodiversity conservation.

  10. Source apportionment and health effect of NOx over the Pearl River Delta region in southern China.

    PubMed

    Lu, Xingcheng; Yao, Teng; Li, Ying; Fung, Jimmy C H; Lau, Alexis K H

    2016-05-01

    As one of the most notorious atmospheric pollutants, NOx not only promotes the formation of ozone but also has adverse health effects on humans. It is therefore of great importance to study the sources of NOx and its effects on human health. The Comprehensive Air Quality Model (CAMx) modeling system and ozone source apportionment technology (OSAT) were used to study the contribution of NOx from different emission sources over southern China. The results indicate that heavy duty diesel vehicles (HDDVs) and industrial point sources are the two major local NOx sources, accounting for 30.8% and 18.5% of local NOx sources, respectively. In Hong Kong, marine emissions contributed around 43.4% of local NOx in 2011. Regional transport is another important source of this pollutant, especially in February and November, and it can contribute over 30% of ambient NOx on average. Power plant point emission is an significant regional source in Zhuhai, Zhongshan and Foshan. The total emission sources are estimated to cause 2119 (0-4405) respiratory deaths and 991 (0-2281) lung cancer deaths due to long-term exposure to NOx in the Pearl River Delta region. Our results suggest that local governments should combine their efforts and vigorously promote further reduction of NOx emissions, especially for those sources that make a substantial contribution to NOx emissions and affect human health: HDDV, LDGV, industrial point sources and marine sources. PMID:26845361

  11. Comparison between visual and passive acoustic detection of finless porpoises in the Yangtze River, China.

    PubMed

    Akamatsu, T; Wang, D; Wang, K; Wei, Z

    2001-04-01

    Recently, sonar signals and other sounds produced by cetaceans have been used for acoustic detection of individuals and groups in the wild. However, the detection probability ascertained by concomitant visual survey has not been demonstrated extensively. The finless porpoises (Neophocaena phocaenoides) have narrow band and high-frequency sonar signals, which are distinctive from background noises. Underwater sound monitoring with hydrophones (B&K8103) placed along the sides of a research vessel, concurrent with visual observations was conducted in the Yangtze River from Wuhan to Poyang Lake in 1998 in China. The peak to peak detection threshold was set at 133 dB re 1 ,EPa. With this threshold level, porpoises could be detected reliably within 300 m of the hydrophone. In a total of 774-km cruise, 588 finless porpoises were sighted by visual observation and 44 ,864 ultrasonic pulses were recorded by the acoustical observation system. The acoustic monitoring system could detect the presence of the finless porpoises 82% of the time. A false alarm in the system occurred with a frequency of 0.9%. The high-frequency acoustical observation is suggested as an effective method for field surveys of small cetaceans, which produce high-frequency sonar signals.

  12. Floristic Characteristics and Biodiversity Patterns in the Baishuijiang River Basin, China

    NASA Astrophysics Data System (ADS)

    Liu, Bing; Zhao, Wenzhi; Wen, Zijuan; Teng, Jirong; Li, Xiaohong

    2009-07-01

    A case study was conducted on the forest ecosystem in the Baishuijiang River basin of China to reveal the influences of environmental factors and human disturbance on the floristic characteristics and biodiversity patterns. Field surveys of the floristic composition, environmental factors, and disturbance factors were conducted along an elevation gradient, and the relationships between biodiversity pattern and environmental factors were analyzed using CCA (canonical correspondence analysis). The results showed that the floristic composition of higher plants consisted of 197 families, 796 genera, 2165 species, 19 subspecies, 239 varietas, and 12 forma, and it was characterized by the multi-geographic composition and by the transition from tropical to temperate zones. Along an elevation gradient, the variations in α and β diversity were best described by a bimodal curve, and the peak values occurred at middle elevations. The CCA indicated that the elevation had the greatest influence on the biodiversity pattern, followed by the topographic index, slope direction, slope, slope position, slope shape, and vegetation coverage. In addition, human disturbance has greatly impacted the floristic composition and biodiversity patterns, and the biodiversity indices were higher with intermediate disturbance at middle elevations compared to higher and lower disturbances at low and high elevations, respectively. This reflected a disturbance-diversity pattern and thus revealed the obvious importance to maintain the intermediate disturbance for biodiversity conservation.

  13. The Ailao Shan-Red River shear zone (Yunnan, China), Tertiary transform boundary of Indochina

    NASA Astrophysics Data System (ADS)

    Leloup, Philippe Hervé; Lacassin, Robin; Tapponnier, Paul; Schärer, Urs; Zhong, Dalai; Liu, Xiaohan; Zhang, Liangshang; Ji, Shaocheng; Trinh, Phan Trong

    1995-12-01

    The Red River Fault zone (RRF) is the major geological discontinuity that separates South China from Indochina. Today it corresponds to a great right-lateral fault, following for over 900 km the edges of four narrow (< 20 km wide) high-grade gneiss ranges that together form the Ailao Shan-Red River (ASRR) metamorphic belt: the Day Nui Con Voi in Vietnam, and the Ailao, Diancang and Xuelong Shan in Yunnan. The Ailao Shan, the longest of those ranges, is fringed to the south by a strip of low-grade schists that contain ultramafic bodies. The ASRR belt has thus commonly been viewed as a suture. A detailed study of the Ailao and Diancang Shan shows that the gneiss cores of the ranges are composed of strongly foliated and lineated mylonitic gneisses. The foliation is usually steep and the lineation nearly horizontal, both being almost parallel to the local trend of the gneissic cores. Numerous shear criteria, including asymmetric tails on porphyroclasts, C-S or C'-S structures, rolling structures, asymmetric foliation boudinage and asymmetric quartz axis fabrics, indicate that the gneisses have undergone intense, progressive left-lateral shear. P-T studies show that left-lateral strain occurred under amphibolite-facies conditions (3-7 kb and 550-780°C). In both ranges high-temperature shear was coeval with emplacement of leucocratic melts. Such deformed melts yield {U}/{Pb} ages between 22.4 and 26.3 Ma in the Ailao Shan and between 22.4 and 24.2 Ma in the Diancang Shan, implying shear in the Lower Miocene. The mylonites in either range rapidly cooled to ≈ 300°C between 22 and 17 Ma, before the end of left-lateral motion. The similarity of deformation kinematics, P-T conditions, and crystallization ages in the aligned Ailao and Diancang Shan metamorphic cores, indicate that they represent two segments of the same Tertiary shear zone, the Ailao Shan-Red River (ASRR) shear zone. Our results thus confirm the idea that the ASRR belt was the site of major left

  14. Seasonality in polybrominated diphenyl ether concentrations in the atmosphere of the Yangtze River Delta, China.

    PubMed

    Zhang, Lifei; Dong, Liang; Huang, Yeru; Shi, Shuangxin; Yang, Wenlong; Zhou, Li

    2016-05-01

    Polybrominated diphenyl ether (PBDE) concentrations in the atmosphere in rapidly developing parts of China have been studied little. In this study, polyurethane foam disk passive air samplers were used to comprehensively investigate PBDE concentrations in the atmosphere of the Yangtze River Delta in different seasons in 2010 and 2011. The mean sum of the concentrations of 13 PBDE congeners was 3.3 pg/m(3) in spring, 7.3 pg/m(3) in summer, 1.0 pg/m(3) in autumn, and 12 pg/m(3) in winter. Higher PBDE concentrations were found in urban areas than in rural areas. The PBDE concentrations were comparable to concentrations that have been found in cities around the world. BDE28, BDE47, BDE99, BDE153, and BDE183 were the dominant PBDE congeners in all seasons. High PBDE concentrations were found in satellite cities, such as Changshu, Wujiang, and Zhangjiagang, suggesting that commercial PBDEs (including pentabromodiphenyl ether products) are produced and/or used in those cities. The PBDE concentrations in the atmosphere were used to estimate daily doses through the inhalation of outdoor air. The most severe risks posed by exposure to PBDEs were found to occur in winter, for both adults and children, but the PBDE concentrations were found not to pose appreciable risks to human health.

  15. Simulating the hydrological responses to climate change of the Xiang River basin, China

    NASA Astrophysics Data System (ADS)

    Wang, Guoqing; Zhang, Jianyun; Pagano, Thomas C.; Xu, Yueping; Bao, Zhenxin; Liu, Yanli; Jin, Junliang; Liu, Cuishan; Song, Xiaomeng; Wan, Sicheng

    2016-05-01

    The responses of stream flow, actual evaporation, and soil moisture to climate change in six catchments within Xiang River basin, China, are investigated using Variable Infiltration Capacity (VIC) model. Results show that stream flows are highly correlated to precipitation while weakly correlated to temperature, which indicates precipitation governs variability of stream flow for these catchments. The VIC model performs well at simulating monthly discharge, with Nash Sutcliffe Efficiencies (NSEs) exceeding 70 % and relative errors (REs) of the volumetric fit falling in the range of ±10 % for both calibration and validation periods. The model can simulate seasonal cycles of soil moisture and actual evaporation reasonably well. Due to humid climate of the region, stream flows are more sensitive to changes in precipitation than to change in temperature, while soil moisture and actual evaporation tend to be relatively more affected by temperature. A 2 °C rise in temperature will lead to 5.62 % (4.3-7.45 %) decrease in stream flow, 6.45 % (5.8-7.02 %) increase in actual evaporation, and 5 % (4.16-5.59 %) decrease in soil moisture. A 10 % increase in precipitation will result in 14.17 % (13.44-15.70 %), 5.22 % (4.32-5.62 %), and 4.57 % (2.90-4.96 %) increases in stream flow, actual evaporation, and soil moisture, respectively.

  16. Regional dynamics of persistent organic pollutants (POPs) in the Pearl River Delta, China: implications and perspectives.

    PubMed

    Zhang, Kai; Zhang, Bao-Zhong; Li, Shao-Meng; Zeng, Eddy Y

    2011-10-01

    The mass transport budgets of 1,1,1-trichloro-2,2-bis(chlorophenyl)ethane (p,p'-DDT) and decabromodiphenyl ether (BDE-209) in the Pearl River Delta, South China were calculated based on previously collected data. Residual p,p'-DDT, mostly related to historical use, has largely settled into soil (780,000 kg), while the soil BDE-209 inventory (44,000 kg) is considerably smaller. Conversely, large amounts of BDE-209 currently used in numerous commercial products have resulted in a much higher atmospheric depositional flux of BDE-209 (28,100 kg/yr) relative to p,p'-DDT (310 kg/yr). The soil inventory of p,p'-DDT is predicted to decrease to half of its current value after 22 years, and the percent area containing soil p,p'-DDT at levels exceeding the effects range-medium (27 ng/g) will decrease from 40% to 20%. Finally, soil BDE-209 inventory will reach an equilibrium value of 940 tons in ~60 years, when BDE-209 levels in 50% of soil will be above an equivalent risk guideline value (125 ng/g).

  17. Remotely sensed assessment of water quality levels in the Pearl River Estuary, China.

    PubMed

    Chen, Chuqun; Tang, Shiling; Pan, Zhilin; Zhan, Haigang; Larson, Magnus; Jönsson, Lennart

    2007-08-01

    In this paper, a method of assessing water quality from satellite data is introduced. The composite pollution index (CPI) was calculated from measured chemical oxygen demand (COD) and nutrient concentration. The relationships between CPI and 240 band combinations of SeaWiFS water-leaving radiance were analyzed and the optimal band combination for estimating CPI was chosen from the 240 band combinations. An algorithm for retrieval of CPI was developed using the optimal band combination, (L(443)xL(510))/(L(412)+L(490)). The CPI was estimated from atmospherically corrected SeaWiFS data by employing the algorithm. Furthermore, the CPI value range for each water quality level was determined based on data obtained from 850 samples taken in the Pearl River Estuary. The remotely sensed CPIs were then transferred to water quality levels and appropriate maps were derived. The remotely sensed water quality level maps displayed a similar distribution of levels based on in situ investigation issued by the State Ocean Administration, China. This study demonstrates that remote sensing can play an important role in water quality assessment.

  18. [Analysis of heavy metals distribution characteristics and pollution assessment in agricultural region soils of Huaihe basin].

    PubMed

    Xiao, Xue; Zhao, Nan-Jing; Yuan, Jing; Ma, Ming-Jun; Fang, Li; Wang, Yin; Meng, De-Shuo; Yu, Yang; Tang, Jie; Zhang, Xiao-Ling; Dai, Yuan; Zhang, Yu-Jun; Liu, Jian-Guo; Liu, Wen-Qing

    2014-07-01

    By means of field sampling and laboratory analysis, the content distribution characteristics of Cd, Cr, Cu, Ni, Pb and Zn in agricultural region soils of Huaihe basin in Anhui province were analyzed. Assessment of heavy metal pollutions was conducted using enrichment factor, geoaccumulation index and potential ecological risk index. The results showed that the average mass fraction of Cd and Cu was 0.113 5 and 22.09 mg x kg(-1) respectively in the study area soil, which were above the background values 0.097 and 20.4 mg x kg(-1) in Anhui Province. The average mass fraction of other four heavy metals did not exceed the average values of Anhui Province. The results of the evaluations from geoaccumulation index and ecological risk assessment discovered that Cd is the strongest pollution metal among six heavy metals in the study area soil. For some samples of the study soil, Cd was slight risk for the ecosystem. The ecosystem risks caused by the other five heavy metals were not obviously for the sampling points. The entire study area soils were mid integrated potential ecological risk.

  19. An inventory of the emission of ammonia from agricultural fertilizer application in China for 2010 and its high-resolution spatial distribution

    NASA Astrophysics Data System (ADS)

    Xu, Peng; Zhang, Yisheng; Gong, Weiwei; Hou, Xikang; Kroeze, Carolien; Gao, Wei; Luan, Shengji

    2015-08-01

    In an agricultural county like China, agricultural fertilizers are the source of ammonia (NH3) emissions. However, the spatial variability in NH3 emissions is large, and the associated uncertainties affect the reliability of total NH3 emission estimates. In this study, an inventory is presented for NH3 emissions from China's agricultural fertilizer application at the city-level, and on a 1 × 1 km grid for croplands in 2010. We present NH3 emissions by source, the temporal and spatial patterns, and the associated uncertainties. The inventory is based on high-resolution activity data, regional emission factors (EFs) and related parameters that are derived from local studies. We compare our emissions estimates with previous inventories from EDGAR and other studies. The total NH3 emissions from China's agricultural fertilizer is 10.7 (8.9-12.3) TgNH3·yr-1. Livestock manure spreading contributes 47.5% to the total emissions, and synthetic fertilizer use by 41.9%. Rural excrement (5.0%) and cake fertilizer (5.5%) are relatively small sources. The spatial pattern of NH3 emissions from China's agricultural fertilizer were primarily concentrated in the North China Plain, the Songliao Plain, the Huaihe River Basin, the Middle-Lower Yangtze Plain, the Pearl River Delta Plain, the Sichuan Basin, the Tarim basin and the Leizhou Peninsula. Approximately 50% of the emissions are from only 76 cities. Our temporal analysis reveals a clear seasonal pattern in NH3 emissions: highest and lowest emissions are calculated for summer and winter, accounting for 42% and 14% of the total emissions, respectively. Peak emissions are calculated for July (1.7 TgNH3·yr-1) and lowest emissions for January (0.5 TgNH3·yr-1). The emissions are correlated with temperature, planting time and cultivation practices.

  20. Vegetation and carbon sequestration and their relation to water resources in an inland river basin of Northwest China.

    PubMed

    Kang, E; Lu, L; Xu, Z

    2007-11-01

    In the Heihe River Basin in the arid inland area of northwest China, the distribution of water resources in vegetation landscape zones controls the ecosystems. The carbon sequestration capacity of vegetation is analyzed in relation to water resources and vegetation growing conditions. During the last 20 years, the vegetation ecosystems have degenerated in the Heihe River Basin. Simulation using the C-FIX model indicates that, at present, the total amount of NPP of vegetation accounts for about 18.16 TgC, and the average value is 106 gC/m(2)/yr over the whole basin. NPP has generally the highest value in the upperstream mountain area, middlestream artificial oases area, downstream river bank area, alluvial fan and the terminal lake depression where vegetation grows relatively well. The lowest value is found in the vast downstream desert and Gobi area. Protection of vegetation ecosystems and enhancement of carbon sequestration require such inland river basins as the Heihe River Basin to be brought under management in a comprehensive way, taking water as a key, to carry out a rational and efficient allocation and utilization of water resources. PMID:17126989

  1. Holocene environment changes around the Sara Us River, northern China, revealed by optical dating of lacustrine-aeolian sediments

    NASA Astrophysics Data System (ADS)

    Zhao, Hui; Sheng, Yongwei; Li, Bo; Fan, Yuxin

    2016-04-01

    The Sara Us River is located along the boundary of the Mu Us Desert and the Chinese Loess Plateau in northern China. The river has cut down through Quaternary sediments creating 70-80 m deep valleys with thick lacustrine/aeolian sequences exposed. We applied optical stimulated luminescence on sediments from a Holocene section of aeolian sand/lacustrine deposits in the top of the river valley. The dating results show that a humid period existed from 7.1 to 2.0 ka ago as evidenced by two layers of peat and lacustrine sediments. However, compared to other published Holocene sections in the Sara Us River valleys close to the section under studying, the local environment experienced very complicated changes during the Holocene. All of the sections recorded a period with drought and/or cold before the Holocene at around 13 ka, and an episode of aridity after about 2 ka ago as evidenced by the layers of aeolian sand. However, the ages of the lacustrine and peat layers in these sections are substantially different. Geomorphological analysis by digital elevation models does not support the existence of a mega lake covering the study area at 2 ka. The intricate environmental changes may have been caused by the meandering of the Sara Us River. Environmental changes also strongly affected human migration in this area, which is documented by Chinese historical records.

  2. [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. PMID:25796880

  3. 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

  4. 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.

  5. Heavy Metal Pollution, Fractionation, and Potential Ecological Risks in Sediments from Lake Chaohu (Eastern China) and the Surrounding Rivers.

    PubMed

    Zhang, Lei; Liao, Qianjiahua; Shao, Shiguang; Zhang, Nan; Shen, Qiushi; Liu, Cheng

    2015-11-06

    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.

  6. Comparison of sedimentary PAHs in the rivers of Ammer (Germany) and Liangtan (China): differences between early- and newly-industrialized countries.

    PubMed

    Liu, Ying; Beckingham, Barbara; Ruegner, Hermann; Li, Zhe; Ma, Limin; Schwientek, Marc; Xie, Huan; Zhao, Jianfu; Grathwohl, Peter

    2013-01-15

    As a proxy to trace the impact of anthropogenic activity, sedimentary polycyclic aromatic hydrocarbons (PAHs) are compared between the early industrialized and newly industrialized countries of Germany and China, respectively. Surface sediment samples in the Ammer River of Germany and the Liangtan River of China were collected to compare concentration levels, distribution patterns, and diagnostic plots of sedimentary PAHs. Total concentrations of 16 PAHs in Ammer sediments were significantly higher by a factor of ~4.5 than those in Liangtan. This contrast agrees with an extensive literature survey of PAH levels found in Chinese versus European sediments. Distribution patterns of PAHs were similar across sites in the Ammer River, whereas they were highly varied in the Liangtan River. Pyrogenic sources dominated in both cases. Strong correlations of the sum of 16 PAHs and PAH groups with TOC contents in the Liangtan River may indicate coemission of PAHs and TOC. Poor correlations of PAHs with TOC in the Ammer River indicate that other factors exert stronger influences. Sedimentary PAHs in the Ammer River are primarily attributed to input of diffuse sources or legacy pollution, while sediments in the Liangtan River are probably affected by ongoing point source emissions. Providing further evidence of a more prolonged anthropogenic influence are the elevated black carbon fractions in sedimentary TOC in the Ammer compared to the Liangtan. This implies that the Liangtan River, like others in newly industrialized regions, still has a chance to avoid legacy pollution of sediment which is widespread in the Ammer River and other European waterways.

  7. Extreme precipitation and extreme streamflow in the Dongjiang River Basin in southern China

    NASA Astrophysics Data System (ADS)

    Wang, W.; Chen, X.; Shi, P.; van Gelder, P. H. A. J. M.; Corzo, G.

    2007-07-01

    Extreme hydro-meteorological events have become the focus of more and more studies in the last decade. Due to the complexity of the spatial pattern of changes in precipitation processes, it is still hard to establish a clear view of how precipitation has changed and how it will change in the future. In the present study, changes in extreme precipitation and streamflow processes in the Dongjiang River Basin in southern China are investigated. It was shown that little change is observed in annual extreme precipitation in terms of various indices, but some significant changes are found in the precipitation processes on a monthly basis. The result indicates that when detecting climate changes, besides annual indices, seasonal variations in extreme events should be considered as well. Despite of little change in annual extreme precipitation series, significant changes are detected in several annual extreme flood flow and low-flow series, mainly at the stations along the main channel of Dongjiang River, which are affected significantly by the operation of several major reservoirs. The result highlights the importance of evaluating the impacts of human activities in assessing the changes of extreme streamflows. In addition, three non-parametric methods that are not-commonly used by hydro-meteorology community, i.e., Kolmogorov-Smirnov test, Levene's test and quantile test, are introduced and assessed by Monte Carlo simulation in the present study to test for changes in the distribution, variance and the shift of tails of different groups of dataset. Monte Carlo simulation result shows that, while all three methods work well for detecting changes in two groups of data with large data size (e.g., over 200 points in each group) and big difference in distribution parameters (e.g., over 100% increase of scale parameter in Gamma distribution), none of them are powerful enough for small data sets (e.g., less than 100 points) and small distribution parameter difference (e.g., 50

  8. Land subsidence in the Yangtze River Delta, China revealed from multi-frequency SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Li, Zhenhong; Motagh, Mahdi; Yu, Jun; Gong, Xulong; Wu, Jianqiang; Zhu, Yefei; Chen, Huogen; Zhang, Dengming; Xu, Yulin

    2014-05-01

    Land subsidence is a major worldwide hazard, and its principal causes are subsurface fluid withdrawal, drainage of organic soils, sinkholes, underground mining, hydrocompaction, thawing permafrost, and natural consolidation. Land subsidence causes many problems including: damage to public facilities such as bridges, roads, railroads, electric power lines, underground pipes; damage to private and public buildings; and in some cases of low-lying land, can increase the risk of coastal flooding from storm surges and rising sea-levels. In China, approximately 48600 km2 of land, an area roughly 30 times of the size of the Greater London, has subsided (nearly 50 cities across 16 provinces), and the annual direct economic loss is estimated to be more than RMB 100 million (~12 million). It is believed that the Suzhou-Wuxi-Changzhou region within the Yangtze River Delta is the most severely affected area for subsidence hazards in China. With its global coverage and all-weather imaging capability, Interferometric SAR (InSAR) is revolutionizing our ability to image the Earth's surface and the evolution of its shape over time. In this paper, an advanced InSAR time series technique, InSAR TS + AEM, has been employed to analysed ERS (C-band), Envisat (C-band) and TerraSAR-X (X-band) data collected over the Suzhou-Wuxi-Changzhou region during the period from 1992 to 2013. Validation with precise levelling and GPS data suggest: (1) the accuracy of the InSAR-derived mean velocity measurements is 1-3 mm/yr; (2) InSAR-derived displacements agreed with precise levelling with root mean square errors around 5 mm. It is evident that InSAR TS + AEM can be used to image the evolution of deformation patterns in the Suzhou-Wuxi-Changzhou region over time: the maximum mean velocity decreased from ~12 cm/yr during the period of 1992-1993 to ~2 cm/yr in 2003-2013. This is believed to be a result of the prohibition of groundwater use carried out by Jiangsu provincial government. The combination

  9. Light Absorption of Brown Carbon Aerosol in the Pearl River Delta Region of China

    NASA Astrophysics Data System (ADS)

    Huang, X.

    2015-12-01

    X.F. Huang, J.F. Yuan, L.M. Cao, J. Cui, C.N. Huang, Z.J. Lan and L.Y. He Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, ChinaCorresponding author. Tel.: +86 755 26032532; fax: +86 755 26035332. E-mail address: huangxf@pku.edu.cn (X. F. Huang). Abstract: The strong spectral dependence of light absorption of brown carbon (BrC) aerosol has been recognized in recent decades. The Absorption Angstrom Exponent (AAE) of ambient aerosol was widely used in previous studies to attribute light absorption of brown carbon at shorter wavelengths, with a theoretical assumption that the AAE of black carbon (BC) aerosol equals to unit. In this study, the AAE method was improved by statistical extrapolation based on ambient measurements in the polluted seasons in typical urban and rural areas in the Pearl River Delta (PRD) region of China. A three-wavelength photoacoustic soot spectrometer (PASS-3) and an aerosol mass spectrometer (AMS) were used to explore the relationship between the ambient measured AAE and the ratio of organic aerosol to BC aerosol, in order to extract the more realistic AAE by pure BC aerosol, which were found to be 0.86, 0.82 and 1.02 at 405nm and 0.70, 0.71, and 0.86 at 532nm in the campaigns of urban-winter, urban-fall, and rural-fall, respectively. Roadway tunnel experiment results further supported the effectiveness of the obtained AAE for pure BC aerosol. In addition, biomass burning experiments proved higher spectral dependence of more-BrC environment and further verified the reliability of the instruments' response. Then, the average light absorption contribution of BrC aerosol was calculated to be 11.7, 6.3 and 12.1% (with total relative uncertainty of 7.5, 6.9 and 10.0%) at 405nm and 10.0, 4.1 and 5.5% (with total relative uncertainty of 6.5, 8.6 and 15.4%) at 532nm of the three campaigns, respectively. These results indicate that the

  10. Mercury speciation and emission from municipal solid waste incinerators in the Pearl River Delta, South China.

    PubMed

    Chen, Laiguo; Liu, Ming; Fan, Ruifang; Ma, Shexia; Xu, Zhencheng; Ren, Mingzhong; He, Qiusheng

    2013-03-01

    The potential for Hg release during municipal solid waste incineration (MSWI) is attracting increased attention due to high volume of municipal waste being treated by incineration in China. Emission amounts have been estimated using emission factors developed for other countries. To fine tune our emission estimate total mercury (THg) and mercury speciation were measured using isokinetic sampling in eight plants, of which six used grate furnace combustor (GFC) and two circulation fluidized bed combustors (CFBCs). Results showed that average THg concentration (19.5 ± 13.6 μg/Nm) in flue gas at the facilities that used CFBC was significantly lower than that at those using GFC (51.4 ± 28.3 μg/Nm, p=0.002). Gaseous oxidized mercury (GOM), gaseous elemental mercury (GEM, Hg), and particulate mercury (Hg) represented 95.5 ± 3.8%, 4.1 ± 3.9% and 0.4 ± 0.3% in GFC, and 63.8 ± 8.6%, 33.6 ± 10.5% and 2.6 ± 1.9% in CFBC, respectively. The measured average THg emission factor for the 8 MSWI plants was 208 ± 130 mg/t in the Pearl River Delta (PRD) region, with 217 ± 158 mg/t and 188 ± 17.7 mg/t were from GFC and CFBC, respectively. Using the average emission factor the estimated total mercury emissions from MSWI were 4.67 ± 2.91 t in China, and 770 ± 65.5 kg in the PRD region in 2010. Of these, 4240 ± 210 kg, 408 ± 231 kg and 14.8 ± 14.1 kg, and 688 ± 37 kg, 78.9 ± 40.6 kg and 3.2 ± 3.0 kg were GOM, Hg, and Hg, respectively. Mercury emissions will continue to increase as the amounts of MSW being incinerated increases. PMID:23410861

  11. Secondary salinization and evapotranspiration under mulched drip irrigation condition in Tarim River basin of northwestern China

    NASA Astrophysics Data System (ADS)

    Tian, Fuqiang; Hu, Hongchang; Zhang, Zhi; Hu, Heping

    2013-04-01

    The secondary salinization induced by irrigation has been presented as a crucial threat to agriculture all over the world, especially in semi-arid and arid regions. Mulched drip irrigation (MDI), as a new micro-irrigation approach incorporating surface drip irrigation method and film mulching technique, has been widely applied in water scarce regions including Tarim River basin of northwestern China. However, salts are likely to build up in the surface soil due to the deficient leaching water in such an irrigation condition. To explore this new kind of secondary salinization issue, the oasis eco-hydrology experimental research station were established in 2008 in a cotton field of Xinjiang, northwestern China. More than 40,000 soil samples were collected to monitor soil moisture and salinity condition within the 1.5 meter depth. The patterns of soil salinity distribution under MDI along the horizontal direction as well as vertical direction have been explored. The results did show that secondary salinization tends to occur in the experimental field under mulched drip irrigation, and winter flush could leach most soil salt in the root zone into groundwater and keep salt balance to mitigate the soil salinization. Meanwhile, soil salt always migrates with the soil water flux such as irrigation and groundwater recharge. Therefore the understanding of water balance is of great importance for estimating soil salinity accumulation, of which evapotranspiration (ET) is the key process, especially in the semi-arid and arid area. In our study, in order to quantify the relation between salinity balance and water balance, ET were derived from a range of measurement systems including eddy covariance, soil water budget (gravimetric methods, Hydra probe, TDT probe and groundwater table sensor, et al.), sap flow and portable photosynthetic system during cotton growing period. Our study is unique in its focus on ET scale issue ranging from leaf and plant scale to field. The up

  12. Continuous measurement of black carbon aerosol in urban Nanjing of Yangtze River Delta, China

    NASA Astrophysics Data System (ADS)

    Zhuang, B. L.; Wang, T. J.; Liu, J.; Li, S.; Xie, M.; Yang, X. Q.; Fu, C. B.; Sun, J. N.; Yin, C. Q.; Liao, J. B.; Zhu, J. L.; Zhang, Y.

    2014-06-01

    As a short-lived climate forcing agent, black carbon (BC) aerosol plays an important role in climate change, atmospheric environment, and human health. In this study, continuous measurements of BC and trace gases were made at an urban site in Nanjing, Yangtze River Delta (YRD) of China in 2012. The annual mean BC concentration in Nanjing was found to be 4157 ± 2626 ng/m3, with a range of 221-24,686 ng/m3. The value was much lower than that in most megacities of China and also lower than that in LinAn, a rural site in YRD. BC concentrations in Nanjing showed strong seasonality, high in spring and autumn and low in summer. The concentrations also varied diurnally, high at rush hours and low in the afternoon. The diurnal cycles of BC loadings in winter to spring 2012 were similar to those in 2011 in magnitude and shape. BC concentrations followed a typical lognormal pattern, with over 75% of data samples between 1000 and 6000 ng/m3. The maximum frequency occurred in low BC concentrations in summer and high BC concentrations in other seasons. In Nanjing, high levels of BC were mainly caused by local and regional emissions. Low levels of BC were mostly associated with winds from northern and eastern directions of Nanjing. BC and CO varied similarly with season, having a correlation coefficient over 0.7 in most seasons. Annual mean ΔBC/ΔCO was about 7 ng/m3/ppb, implying that the sources of the BC likely came from combustions of bio-fuel, industry-coal, and vehicle-gasoline. Serious pollution episodes with high levels of BC were detected in early June at the site. Analysis suggested that the episodes were due to biomass burning in northwestern region of Nanjing. During this period, ΔBC/ΔCO reached about 9.7 ng/m3/ppb and much higher BC levels were found at mid-night.

  13. 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

    2013-08-01

    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).

  14. A Google Earth-based surveillance system for schistosomiasis japonica implemented in the lower reaches of the Yangtze River, China

    PubMed Central

    2011-01-01

    Background Due to the success of the national schistosomiasis control programme in China, transmission has been sufficiently reduced in many areas to severely limit identification of areas at risk by conventional snail surveys only. In this study, we imported Google Earth technology and a Global Positioning System (GPS) into the monitoring system for schistosomiasis surveillance of the banks of the Yangtze River in Jiangsu Province, China. Methods A total of 45 sites were selected and the risk was assessed monthly by water exposure of sentinel mice at these sites from May to September in 2009 and 2010. The results were assembled and broadcast via the Google Earth platform. Results The intensity of schistosomiasis transmission showed peaks of risk in June and September of 2009, while there was only one small peak in June in 2010 as the number of detected positive transmission sites dropped dramatically that year thanks to improved mollusciciding. River ports were found to be areas of particular risk, but ferry terminals and other centres of river-related activities were also problematic. Conclusions The results confirm that the surveillance system can be rapidly updated and easily maintained, which proves the Google Earth approach to be a user-friendly, inexpensive warning system for schistosomiasis risk. PMID:22117601

  15. 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. PMID:27486043

  16. Analysis of agricultural land use change in the middle reach of the Heihe River Basin, Northwest China.

    PubMed

    Fu, Li; Zhang, Lanhui; He, Chansheng

    2014-03-04

    The Heihe River Basin (HRB) is the second largest inland river basin in arid Northwest China. The expanding agricultural irrigation, growing industrialization, and increasing urban development in the middle reach have depleted much of the river flow to the lower reach, degrading the corresponding ecosystems. Since the enactment of the State Council of China's new HRB water allocation policy in 2000 tremendous land use and land cover (LULC) changes have taken place to reduce water consumption in the middle reach and deliver more water downstream. This paper analyzes LULC changes during the period of 2000-2009 to understand how the changing land use patterns have altered water resource dynamics in the region. Results, while yet to be further verified in the field, show that from 2000 to 2009, urban, agricultural land, rangeland, and forest areas have increased, and barren area has decreased. Within the cropland, rice (a high water consumption crop) planting area decreased, while corn and wheat (relatively lower water consumption crops) planting areas increased. These changes in land use patterns, especially in the agricultural zones, have ensured the discharge of the required amount of water to the lower reach.

  17. 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.

  18. Variation in abundance and composition of methane-metabolizing microorganisms from the lower Pearl River to the South China Sea

    NASA Astrophysics Data System (ADS)

    Wang, P.

    2015-12-01

    Methane is a significant greenhouse gas, which is regulated by microbial processes in surficial environments. However, the population dynamics of methanogens and methanotrophs in a particular environment has not been well studied. In this project, the variation of methanogens and methanotrophs in the sediment of the Pearl River estuary and coastal South China Sea was examined along a salinity gradient (A:0.8‰; B: 18.1‰; C: 23.9‰: D: 31‰)over a period of one year. Quantitative PCR showed that the variation in archaeal and bacterial 16S rRNA gene abundance at site A in the lower Pearl River (from 3.6×103 to 2.6×105 copies/L for archaea and from 1.2×105 to 2.6×106 copies/L for bacteria) is larger than that in at site D in the coastal South China Sea (from 3.5×104 to 2.9×105 copies/L for archaea and from 8.8×105 to 3.2×106 copies/L for bacteria). High throughput sequencing showed that methanogens and methanotrophs were abundant in the sediment of lower Pearl River and decreased sharply with the increasing salinity. Our results indicate that active methane metabolism is favored in the freshwater environment.

  19. Spatial-temporal variations of dominant drought/flood modes and the associated atmospheric circulation and ocean events in rainy season over the east of China

    NASA Astrophysics Data System (ADS)

    Huang, Shaoni; Huang, Fei

    2012-06-01

    By using Season-reliant Empirical Orthogonal Function (S-EOF) analysis, three dominant modes of the spatial-temporal evolution of the drought/flood patterns in the rainy season over the east of China are revealed for the period of 1960-2004. The first two leading modes occur during the turnabout phase of El Niño-Southern Oscillation (ENSO) decaying year, but the drought/flood patterns in the rainy season over the east of China are different due to the role of the Indian Ocean (IO). The first leading mode appears closely correlated with the ENSO events. In the decaying year of El Niño, the associated western North Pacific (WNP) anticyclone located over the Philippine Sea persists from the previous winter to the next early summer, transports warm and moist air toward the southern Yangtze River in China, and leads to wet conditions over this entire region. Therefore, the precipitation anomaly in summer exhibits a `Southern Flood and Northern Drought' pattern over East China. On the other hand, the basin-wide Indian Ocean sea surface temperature anomaly (SSTA) plays a crucial role in prolonging the impact of ENSO on the second mode during the ENSO decaying summer. The Indian Ocean basin mode (IOBM) warming persists through summer and unleashes its influence, which forces a Matsuno-Gill pattern in the upper troposphere. Over the subtropical western North Pacific, an anomalous anticyclone forms in the lower troposphere. The southerlies on the northwest flank of this anticyclone increase the moisture transport onto central China, leading to abundant rainfall over the middle and lower reaches of the Yangtze River and Huaihe River valleys. The anomalous anticyclone causes dry conditions over South China and the South China Sea (SCS). The precipitation anomaly in summer exhibits a `Northern Flood and Southern Drought' pattern over East China. Therefore, besides the ENSO event the IOBM is an important factor to influence the drought/flood patterns in the rainy season over

  20. Black carbon measurements in the Pearl River Delta region of China

    NASA Astrophysics Data System (ADS)

    Huang, X.; Gao, R.; Schwarz, J. P.; Ling-Yan, H.; Fahey, D. W.; Laurel A, W.; Zeng, L.

    2009-12-01

    The Pearl River Delta (PRD) region in southeastern China is one of the most polluted industrial/metropolitan areas in the world. The 3C-STAR campaign (Synthesized Prevention Techniques for Air Pollution Complex and Integrated Demonstration in Key City-Cluster Region), carried out in October-November, 2008, was aimed at improving the understanding and quantification of air pollution in the region, while developing technical capacity for regional air quality monitoring and modeling. We report single-particle soot photometer (SP2) measurements and analyses of refractory black carbon (rBC) at Kaiping, a rural site downwind of the major pollution sources in the PRD area. The rBC mass loadings varied between 0.5 and 10 µg-rBC kg-air-1, and averaged 2.8 µg-rBC kg-air-1. These values are roughly an order of magnitude higher than those measured in the Houston, Texas, a major US metropolitan area. The rBC mass distributions show a primary lognormal peak with a median mass diameter of 0.22 µm volume-equivalent diameter (VED), which is similar to those observed in Houston and other regions with the SP2 instrument. A second mode with a mass median diameter of 0.69 µm VED, has not been observed before. Coatings are found on over 50% of rBC particles, suggesting that they are aged and/or of biomass-burning origin. The high rBC loadings cause significant heating of the atmosphere due to direct solar absorption. A diurnal heating rate of over 0.5 K day-1. is estimated for the average of entire dataset with a maximum heating rate near 3 K day-1.

  1. Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China.

    PubMed

    Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

    2016-05-01

    A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC-MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEslow, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16-5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. PMID:26845362

  2. Halocarbons in the atmosphere of the industrial-related Pearl River Delta region of China

    NASA Astrophysics Data System (ADS)

    Chan, L. Y.; Chu, K. W.

    2007-02-01

    In a study conducted in 2000, 19 halocarbons from 78 canister air samples were measured in five industrial cities in the Pearl River Delta (PRD), one of the fastest growing industrial regions in China. Preliminary year 2000 halocarbon levels have been derived using available data and information. Comparisons have been made between the data obtained in this study and the corresponding estimated global/tropical surface mixing ratios obtained from the literature. With the exception of CFC-114 and halon-2402, the halocarbons had significant enhancements, presumably due to their recent increased production and extensive industrial uses. In contrast to the small enhancements (<7%) for two chlorofluorocarbons (CFC-11 and CFC-12), large enhancements (>30%) for three HCFC replacements (HCFC-22, -141b, -142b) were observed. In general, HCFCs have virtually replaced CFCs, except for some localized usage. The median of HFC-134a also had a 36% enhancement; however, 23% of the samples were near or at the global background level. These contradictory results could not give a clear situation of uses of this new chemical in the region. Our data also indicate that halocarbon-based cleaning solvents, including CFC-113, methyl chloroform, trichloroethene and tetrachloroethene, were still frequently used in PRD industries. High mixing ratios of these halogenated solvents were frequently measured in Dongguan, a city with light industry. Higher atmospheric levels of the three methyl halides (-Cl, -Br, and -I) were found in a coastal city, Jiangmen. These may be contributed to by industrial emissions and coastal terrestrial and coastal seawater sources.

  3. High resolution of black carbon and organic carbon emissions in the Pearl River Delta region, China.

    PubMed

    Zheng, Junyu; He, Min; Shen, Xingling; Yin, Shasha; Yuan, Zibing

    2012-11-01

    A high-resolution regional black carbon (BC) and organic carbon (OC) emission inventory for the year 2009 was developed for the Pearl River Delta (PRD) region, China, based on the collected activity data and the latest emission factors. PM(2.5), BC and OC emissions were estimated to be 303 kt, 39 kt and 31 kt, respectively. Industrial processes were major contributing sources to PM(2.5) emissions. BC emissions were mainly from mobile sources, accounting for 65.0%, while 34.1% of OC emissions were from residential combustion. The primary OC/BC ratios for individual cities in the PRD region were dependent on the levels of economic development due to differences in source characteristics, with high ratios in the less developed cities and low ratios in the central and southern developed areas. The preliminary temporal profiles were established, showing the highest OC emissions in winter and relatively constant BC emissions throughout the year. The emissions were spatially allocated into grid cells with a resolution of 3 km × 3 km. Large amounts of BC emissions were distributed over the central-southern PRD city clusters, while OC emissions exhibited a relatively even spatial distribution due to the significant biomass burning emissions from the outlying area of the PRD region. Uncertainties in carbonaceous aerosol emissions were usually higher than in other primary pollutants like SO(2), NO(x), and PM(10). One of the key uncertainty sources was the emission factor, due to the absence of direct measurements of BC and OC emission rates. PMID:22995707

  4. Observations of relative humidity effects on aerosol light scattering in the Yangtze River Delta of China

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Sun, J. Y.; Shen, X. J.; Zhang, Y. M.; Che, H.; Ma, Q. L.; Zhang, Y. W.; Zhang, X. Y.; Ogren, J. A.

    2015-07-01

    Scattering of solar radiation by aerosol particles is highly dependent on relative humidity (RH) as hygroscopic particles take up water with increasing RH. To achieve a better understanding of the effect of aerosol hygroscopic growth on light scattering properties and radiative forcing, the aerosol scattering coefficients at RH in the range of 40 to ~ 90 % were measured using a humidified nephelometer system in the Yangtze River Delta of China in March 2013. In addition, the aerosol size distribution and chemical composition were measured. During the observation period, the mean and standard deviation (SD) of enhancement factors at RH = 85 % for the scattering coefficient (f(85 %)), backscattering coefficient (fb(85 %)), and hemispheric backscatter fraction (fβ(85 %)) were 1.58 ± 0.12, 1.25 ± 0.07, and 0.79 ± 0.04, respectively, i.e., aerosol scattering coefficient and backscattering coefficient increased by 58 and 25 % as the RH increased from 40 to 85 %. Concurrently, the aerosol hemispheric backscatter fraction decreased by 21 %. The relative amount of organic matter (OM) or inorganics in PM1 was found to be a main factor determining the magnitude of f(RH). The highest values of f(RH) corresponded to the aerosols with a small fraction of OM, and vice versa. The relative amount of NO3- in fine particles was strongly correlated with f(85 %), which suggests that NO3- played a vital role in aerosol hygroscopic growth during this study. The mass fraction of nitrate also had a close relationship to the curvature of the humidograms; higher mass fractions of nitrate were associated with humidograms that had the least curvature. Aerosol hygroscopic growth caused a 47 % increase in the calculated aerosol direct radiative forcing at 85 % RH, compared to the forcing at 40 % RH.

  5. Heavy metal pollution in surface soils of Pearl River Delta, China.

    PubMed

    Jinmei, Bai; Xueping, Liu

    2014-12-01

    Heavy metal pollution is an increasing environmental problem in Chinese regions undergoing rapid economic and industrial development, such as the Pearl River Delta (PRD), southern China. We determined heavy metal concentrations in surface soils from the PRD. The soils were polluted with heavy metals, as defined by the Chinese soil quality standard grade II criteria. The degree of pollution decreased in the order Cd > Cu > Ni > Zn > As > Cr > Hg > Pb. The degree of heavy metal pollution by land use decreased in the order waste treatment plants (WP) > urban land (UL) > manufacturing industries (MI) > agricultural land (AL) > woodland (WL) > water sources (WS). Pollution with some of the metals, including Cd, Cu, Ni, and Zn, was attributed to the recent rapid development of the electronics and electroplating industries. Cd, Hg, and Pb (especially Cd) pose high potential ecological risks in all of the zones studied. The soils posing significantly high and high potential ecological risks from Cd covered 73.3 % of UL, 50 % of MI and WP land, and 48.5 % of AL. The potential ecological risks from heavy metals by land use decreased in the order UL > MI > AL > WP > WL > WS. The control of Cd, Hg, and Pb should be prioritized in the PRD, and emissions in wastewater, residue, and gas discharges from the electronics and electroplating industry should be decreased urgently. The use of chemical fertilizers and pesticides should also be decreased. PMID:25252793

  6. Tectonic Subsidence Analysis of the Pearl River Mouth Basin, Northern South China Sea

    NASA Astrophysics Data System (ADS)

    Tang, X.; Huang, S. S. X. E. C.; Zhuang, W.; LIU, Z.; Duan, W.; Hu, S.

    2015-12-01

    The Pearl River Mouth Basin (PRMB hereafter) in the northern margin of the South China Sea has attracted great attention not only because of its special tectonic location but also for its abundant hydrocarbon resources. Tectonic evolution controls the petroleum geological condition of hydrocarbon-bearing basins. Efforts have been made to understand the tectonic evolution of this basin. However, many issues about the tectonic features and the evolution process of this basin, such as the age of the breakup unconformities and the anomalously accelerated subsidence during the post-rifting stage, remain controversial. Here we employ tectonic subsidence analysis of sedimentary basins, a technique of removing isostatic loading and compaction effects by back-stripping, to investigate the tectonic controls on the basin formation of the PRMB. We performed the analysis on 4 drill wells and 43 synthetic wells constructed based on recently acquired seismic profiles. The result shows that tectonic subsidence in the eastern sags of the PRMB began to decrease at ~30Ma while in the western sags the onset was ~23.8Ma. This suggests that the break-up time i.e. the end of rifting in the PRMB is earlier in the eastern sags than in the western sags. Abnormally accelerated tectonic subsidence occurred between 17.5-16.4Ma during the post-rifting stage, at an average subsidence rate as high as 301.9m/Ma. This phenomenon discriminates the PRMB from the category of classical Atlantic passive continental marginal basins, of which the tectonic subsidence during the post-rifting stage decays exponentially. The main objective of this paper is to provide insights into the geological and geodynamic evolution of the PRMB. The result bears significance to hydrocarbon exploration in this region.

  7. Distribution of phthalate esters in topsoil: a case study in the Yellow River Delta, China.

    PubMed

    Hongjun, Yang; Wenjun, Xie; Qing, Liu; Jingtao, Liu; Hongwen, Yu; Zhaohua, Lu

    2013-10-01

    The Yellow River Delta (YRD) is a typical agricultural and petrochemical industrial area of China. To assess the current status of phthalate esters (PAEs) of soil residues, soil samples (0∼20 cm) (n = 82) were collected in Bincheng District, at the geographic center of the YRD. PAEs were detected in all topsoil samples analyzed, which indicated that PAEs are ubiquitous environmental contaminants. Concentrations of 11 PAEs are in the range of 0.794∼19.504 μg g(-1), with an average value of 2.975 μg g(-1). It was presented that PAEs pollution in this area was weak and monotonously increasing along the rural-urban gradient. Higher concentrations were observed from roadsides (and/or gutters), densely anthropogenic activities areas (such as the urbanization and industrialization), and agriculture influence district, which mainly originated from construction waste, municipal sewage, agricultural waste and pesticide, discarded plastic effusion and atmospheric depositions. Concentrations of PAEs were weakly positivity correlated with soil organic carbon content and pH, which suggested both of them can affect the distribution of PAEs. The concentration of di (2-ethylhexyl) phthalate and di-n-butyl phthalate dominated in the 11 PAEs, with the average values of 0.735 and 1.915 μg g(-1), respectively, and accounted for 92.1 % of the whole PAEs' concentrations. No significant differences of PAE congeneric profiles were observed between our work and others previously reported, which is consistent with the use of similar commercial PAEs around the world. PMID:23609921

  8. Recent changes of water discharge and sediment load in the Zhujiang (Pearl River) Basin, China

    NASA Astrophysics Data System (ADS)

    Zhang, Shurong; Lu, Xi Xi; Higgitt, David L.; Chen, Chen-Tung Arthur; Han, Jingtai; Sun, Huiguo

    2008-02-01

    The paper is concerned with identifying changes in the time series of water and sediment discharge of the Zhujiang (Pearl River), China. The gradual trend test (Mann-Kendall test), and abrupt change test (Pettitt test), have been employed on annual water discharge and sediment load series (from the 1950s-2004) at nine stations in the main channels and main tributaries of the Zhujiang. Both the Mann-Kendall and Pettitt tests indicate that water discharge at all stations in the Zhujiang Basin showed no significant trend or abrupt shift. Annual water discharges are mainly influenced by precipitation variability, while the construction of reservoirs/dams in the Zhujiang Basin had little influence on water discharge. Sediment load, however, showed significant decreasing trends at some stations in the main channel of the Xijiang and Dongjiang. More stations have seen significantly decreasing trends since the 1990s. The decreasing sediment load in the Zhujiang reflects the impacts of reservoir construction in the basin. In contrast, the Liujiang, the second largest tributary of the Xijiang, has experienced a significant upward shift of sediment load around 1991 likely caused by exacerbated rock desertification in the karst regions. The annual sediment load from the Zhujiang (excluding the delta region) to the estuary has declined from 80.4 × 10 6 t averaged for the period 1957-1995 to 54.0 × 10 6 t for the period 1996-2004. More specifically, the sediment load declined steadily since the early 1990s so that in 2004 it was about one-third of the mean level of pre-90s. Water discharge and sediment load of the Zhujiang would be more affected by human activities in the future with the further reservoir developments, especially the completion of the Datengxia hydroelectric project, and an intensification of the afforestation policy in the drainage basin.

  9. High diversity of nitrogen-fixing bacteria in upper reaches of Heihe River, Northwestern China

    NASA Astrophysics Data System (ADS)

    Tai, X. S.; Mao, W. L.; Liu, G. X.; Chen, T.; Zhang, W.; Wu, X. K.; Long, H. Z.; Zhang, B. G.

    2013-03-01

    Vegetation plays a key role to water conservation in southern Qilian Mountains (Northwestern China), the upper reaches of Heihe River. Nitrogen-fixing bacteria are crucial for vegetation protection because they can supply plants with nitrogen source. Nevertheless, little is known about nitrogen-fixing bacteria in this region. In present study, nifH gene clone libraries were established for detecting the difference of nitrogen-fixing bacterial communities between Potentilla parvifolia shrub and Carex alrofusca meadow in the southern Qilian Mountains. All the identified nitrogen-fixing bacterial clones belonged to Proteobacteria. At the genus level, the Azospirillum sp. was only detected in shrub soil while Thiocapsa sp., Derxiasp., Ectothiorhodospira sp., Mesorhizobium sp., Klebsiella sp., Ensifer sp., Methylocella sp. and Peseudomonas sp. were just detected in meadow soil. Shannon-Wiener index of nifH gene ranged from 1.5 to 2.8 and was higher in meadow soil than shrub soil. Contrarily, the nifH gene copies and CFUs of cultured nitrogen-fixing bacteria ranged from 0.4 × 107 to 6.9 × 107 copies g-1 soil and 0.97 × 106 to 12.78 × 106 g-1 soil, respectively. Furthermore, both of them were lower in meadow soil than shrub soil. Statistical analysis revealed that diversity and copies of nifH gene mostly correlated with aboveground biomass in shrub soil. In meadow soil, nifH gene diversity was principally affected by altitude while copies did by soil available K.

  10. Residues of fluoroquinolones in marine aquaculture environment of the Pearl River Delta, South China.

    PubMed

    He, Xiuting; Wang, Zhaohui; Nie, Xiangping; Yang, Yufen; Pan, Debo; Leung, Anna O W; Cheng, Zhang; Yang, Yongtao; Li, Kaibin; Chen, Kunci

    2012-06-01

    Concentrations and distributions of selected fluoroquinolones (norfloxacin, ciprofloxacin and enrofloxacin) in water, sediments and nine kinds of fish species collected from 6 sites in two marine aquaculture regions of the Pearl River Delta, China, were analyzed by using high-performance liquid chromatography with fluorescence detector (HPLC). The results showed that the concentrations of ciprofloxacin and enrofloxacin were below the limits of quantification (LOQ) in all water samples except for norfloxacin. Norfloxacin and ciprofloxacin concentrations ranged from 1.88 to 11.20 ng g(-1) dry wt, 0.76-2.42 ng g(-1) dry wt in sediments collected from the Dapeng'ao region (sites 1-3) and ranged from 2.31 to 4.75 ng g(-1) dry wt, 1.26-1.76 ng g(-1) dry wt in sediments collected from the Hailing Island region (sites 4-6), respectively. However, no enrofloxacin was found in all sediment samples. The three fluoroquinolones (FQs) were detected in all fish samples, and the concentrations were higher in liver tissues than those in muscle tissues. The levels of norfloxacin were higher than ciprofloxacin and enrofloxacin in both liver and muscle tissues. Among the nine marine fish species, Siganus fuscescens from Hailing Island had a significantly high level of norfloxacin in liver tissue (254.58 ng g(-1) wet wt), followed by Sparus macrocephalus (133.15 ng g(-1) wet wt) from Dapeng'ao, and the lowest value was Lutianus argentimaculatus (5.18 ng g(-1) wet wt) from Hailing Island. The obtained results of FQs in present study do not represent a risk to the human health in Guangdong coastal area, based on the maximum residue limits (MRLs) established by Chinese Government and the acceptable daily intake (ADI) recommended by the Food and Agriculture Organization and World Health Organization (FAO/WHO).

  11. Bioactive and total endotoxins in atmospheric aerosols in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Cheng, Jessica Y. W.; Hui, Esther L. C.; Lau, Arthur P. S.

    2012-02-01

    Endotoxin, a toxic and pyrogenic substance in gram-negative bacteria in atmospheric aerosols was measured over a period of one year at Nansha, Guangzhou and Hong Kong in the Pearl River Delta region, China. Atmospheric aerosols were collected by high-volume samplers. The bioactive endotoxin levels in the samples were determined using the Limulus Amebocyte Lysate (LAL) assay after extraction with pyrogen-free water while the total endotoxin levels were measured by quantifying the biomarker, 3-hydroxy fatty acids (3-OHFAs) with GC-MS. Results showed that there was no significant difference (0.19 < p < 0.81) in the bioactive endotoxin level in PM 10 among sites (average concentrations ranged from 0.34 to 0.39 EU m -3). However, Hong Kong showed a significantly lower ( p < 0.05) total endotoxin level in PM 10 (average of 17.4 ng m -3) compared with Nansha's 29.4 ng m -3 and Guangzhou's 32.7 ng m -3. The bioactive endotoxins were found to be associated with the coarse mode (PM 2.5-10) of the particulates of natural origins while the total endotoxins were associated more with the fine mode (PM 2.5) of the particulates of anthropogenic origins. When normalized with particulate mass, the endotoxin loading is much higher in summer as a result of the increased growth of the bacteria when climatic conditions are favorable. The chemically determined total endotoxins were 3-4 orders of magnitude higher than the bioactive endotoxins quantified using the LAL assay. Correlation analyses between the bioactive endotoxins and 3-OHFAs with different carbon length were analyzed. Results showed that the correlations detected vary among sites and particulate sizes. Although no generalization between the total and bioactive endotoxins can be drawn from the study, the levels reported in this study suggests that the discrepancies between the two measurement approaches, and the bioactive potential of 3-OHFAs with individual carbon chains deserve further investigation.

  12. Characteristics and applications of size-segregated biomass burning tracers in China's Pearl River Delta region

    NASA Astrophysics Data System (ADS)

    Zhang, Zhisheng; Gao, Jian; Engling, Guenter; Tao, Jun; Chai, Fahe; Zhang, Leiming; Zhang, Renjian; Sang, Xuefang; Chan, Chuen-yu; Lin, Zejian; Cao, Junji

    2015-02-01

    Biomass burning activities in China are ubiquitous and the resulting smoke emissions may pose considerable threats to human health and the environment. In the present study, size-segregated biomass burning tracers, including anhydrosugars (levoglucosan (LG) and mannosan (MN)) and non-sea-salt potassium (nss-K+), were determined at an urban and a suburban site in the Pearl River Delta (PRD) region. The size distributions of biomass burning tracers were generally characterized by a unimodal pattern peaking in the particle size range of 0.44-1.0 μm, except for MN during the wet season, for which a bimodal pattern (one in fine and one in coarse mode) was observed. These observed biomass burning tracers in the PRD region shifted towards larger particle sizes compared to the typical size distributions of fresh biomass smoke particles. Elevated biomass burning tracers were observed during the dry season when biomass burning activities were intensive and meteorological conditions favored the transport of biomass smoke particles from the rural areas in the PRD and neighboring areas to the sampling sites. The fine mode biomass burning tracers significantly correlated with each other, confirming their common sources. Rather high ΔLG/ΔMN ratios were observed at both sites, indicating limited influence from softwood combustion. High Δnss-K+/ΔLG ratios further suggested that biomass burning aerosols in the PRD were predominately associated with burning of crop residues. Using a simplified receptor-oriented approach with an emission factor of 0.075 (LG/TC) obtained from several chamber studies, average contributions of biomass burning emissions to total carbon in fine particles were estimated to be 23% and 16% at the urban and suburban site, respectively, during the dry season. In contrast, the relative contributions to total carbon were lower than 8% at both sites during the wet season.

  13. 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.

  14. Spatial and temporal variations of river nitrogen exports from major basins in China.

    PubMed

    Ti, Chaopu; Yan, Xiaoyuan

    2013-09-01

    Provincial-level data for population, livestock, land use, economic growth, development of sewage systems, and wastewater treatment rates were used to construct a river nitrogen (N) export model in this paper. Despite uncertainties, our results indicated that river N export to coastal waters increased from 531 to 1,244 kg N km(-2) year(-1) in the Changjiang River basin, 107 to 223 kg N km(-2) year(-1) in the Huanghe River basin, and 412 to 1,219 kg N km(-2) year(-1) in the Zhujiang River basin from 1980 to 2010 as a result of rapid population and economic growth. Significant temporal changes in water N sources showed that as the percentage of runoff from croplands increased, contributions of natural system runoff and rural human and livestock excreta decreased in the three basins from 1980 to 2010. Moreover, the nonpoint source N decreased from 72 to 58 % in the Changjiang River basin, 80 to 67 % in the Huanghe River basin, and 69 to 51 % in the Zhujiang River basin, while the contributions of point sources increased greatly during the same period. Estimated results indicated that the N concentrations in the Changjiang, Huanghe, and Zhujiang rivers during 1980-2004 were higher than those in the St. Lawrence River in Canada and lower than those in the Thames, Donau, Rhine, Seine, and Han rivers during the same period. River N export will reduce by 58, 54, and 57 % for the Changjiang River, Huanghe River, and Zhujiang River in the control scenario in 2050 compared with the basic scenario.

  15. Relationship between Dongting Lake and surrounding rivers under the operation of the Three Gorges Reservoir, China.

    PubMed

    Zhan, Lucheng; Chen, Jiansheng; Zhang, Shiyin; Huang, Dewen; Li, Ling

    2015-01-01

    The natural flow properties of the Yangtze River have been changed completely following the construction of the Three Gorges Dam. The dam's operation has affected the resources and environment in the middle and lower reaches of the Yangtze River, changing the hydrological conditions and ecological environment of the Dongting Lake. During three different dispatching periods of the reservoir, we took triplicate samples of the river and lake water. All the samples were analysed for δ(2)H and δ(18)O to determine the relationship between the lake and the Yangtze River (and other rivers), and to evaluate objectively the influence of the dam's operation on the lake. During the period of water-supply dispatch, the Four Rivers and Miluo River are the main recharge sources of the lake. During the flood-storage dispatching period, the Dongting Lake is recharged largely by the Three Outlets and the Four Rivers, whereas during the period of water-storage dispatch, most of the lake's water originates from the Miluo, Xiang, Zi, and Yuan rivers. Although the Yangtze River only contributes significantly to the lake's recharge through the Three Outlets during the flood-storage dispatching period, the lake discharges large amounts of water into the Yangtze River during all three periods. Through the operation of the reservoir, it should be ensured that the water level of the Dongting Lake is not too low during the dry season, nor too high during the wet season, thus preventing the lake region from future flood and drought disasters.

  16. 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. PMID:25189685

  17. Sedimentary and hydrological studies of the Holocene palaeofloods in the Shanxi-Shaanxi Gorge of the middle Yellow River, China

    NASA Astrophysics Data System (ADS)

    Li, Xiaogang; Huang, Chun Chang; Pang, Jiangli; Zha, Xiaochun; Ma, Yugai

    2015-01-01

    Holocene slackwater deposits along the river channels were used to study the magnitude and frequency of the palaeofloods that occurred prior to gauged and historical data sets all over the world. Palaeohydrological investigations along the Shanxi-Shaanxi Gorge of the middle Yellow River, China, identified palaeoflood slackwater deposits (SWDs) at several sites along the cliffs bordering the river channel. The SWDs are intercalated within Holocene eolian loess-soil profiles and clastic slope deposits. The palaeoflood SWDs were differentiated from eolian loess and soil by the sedimentary criteria and analytical results including magnetic susceptibility and particle-size distribution, similar to the flood SWDs in 2012, which indicated that these well-sorted palaeoflood SWD beds were deposited from the suspended sediment load in floodwaters. They have recorded the extraordinary palaeoflood events which occurred between 3200 and 3000 a BP as dated by the optically stimulated luminescence method in combination with pedostratigraphic correlations with the previously studied Holocene pedo-stratigraphy in the Yellow River drainage basin. Manning slope-area calculations estimate the peak discharged for these palaeoflood events to range from 43,290 to 49,830 m3/s. The drainage area of the study site is 489,900 km2. It is 2.0-2.5 times the largest gauged flood (21,000 m3/s) that has ever occurred since 1934. These events also occurred on Yellow River tributaries, including the Weihe, Jinghe and Qishuihe Rivers. These flood events are therefore considered to be a regional expression of known climatic events in the northern hemisphere and demonstrate Holocene climatic instability. This study provides important data in understanding the interactions between regional hydro-climatic systems and global change in semiarid and subhumid regions.

  18. 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.

  19. 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.

  20. The source of natural and anthropogenic heavy metals in the sediments of the Minjiang River Estuary (SE China): implications for historical pollution.

    PubMed

    Xu, Yonghang; Sun, Qinqin; Yi, Liang; Yin, Xijie; Wang, Aijun; Li, Yunhai; Chen, Jian

    2014-09-15

    Two sedimentary cores in the Minjiang River estuary (SE China) are documented for grain size, clay minerals, heavy metals, magnetic parameters and Pb isotopes to investigate the source and historical variation of heavy metals. The MJK9 core was collected outside of the Minjiang River estuary, and the core is composed of mixed sediments, of which ~70% from the Yangtze River and 30% from the Minjiang River. It is thus difficult to be used for tracing the human activity along the Minjiang River. In contrast, the sediments of MJK16 core which was collected in a nearshore area are primarily from the Minjiang River. The enrichment factors of the sediments were <1.5, indicating minor pollution. The results indicate that the sediments of the MJK16 core have Cu and Pb concentrations increasing since 1980, associated with the increase of magnetic mineral concentration and (206)Pb/(207)Pb and (206)Pb/(208)Pb of the sediments. We compared the Pb isotopic compositions between our results and those for the deposit mining in the Minjiang River basin, and aerosols and coal dust in south China, and considered that Pb in the sediments of the MJK16 core was derived primarily from weathered rocks as well as industrial emission (e.g. coal combustion). The sediments have anthropogenic Pb concentrations ranging from 6% in 1950 to 23.7% in 2010, consistent with the impact of rapid urban and industrial development in China. PMID:24995639

  1. The source of natural and anthropogenic heavy metals in the sediments of the Minjiang River Estuary (SE China): implications for historical pollution.

    PubMed

    Xu, Yonghang; Sun, Qinqin; Yi, Liang; Yin, Xijie; Wang, Aijun; Li, Yunhai; Chen, Jian

    2014-09-15

    Two sedimentary cores in the Minjiang River estuary (SE China) are documented for grain size, clay minerals, heavy metals, magnetic parameters and Pb isotopes to investigate the source and historical variation of heavy metals. The MJK9 core was collected outside of the Minjiang River estuary, and the core is composed of mixed sediments, of which ~70% from the Yangtze River and 30% from the Minjiang River. It is thus difficult to be used for tracing the human activity along the Minjiang River. In contrast, the sediments of MJK16 core which was collected in a nearshore area are primarily from the Minjiang River. The enrichment factors of the sediments were <1.5, indicating minor pollution. The results indicate that the sediments of the MJK16 core have Cu and Pb concentrations increasing since 1980, associated with the increase of magnetic mineral concentration and (206)Pb/(207)Pb and (206)Pb/(208)Pb of the sediments. We compared the Pb isotopic compositions between our results and those for the deposit mining in the Minjiang River basin, and aerosols and coal dust in south China, and considered that Pb in the sediments of the MJK16 core was derived primarily from weathered rocks as well as industrial emission (e.g. coal combustion). The sediments have anthropogenic Pb concentrations ranging from 6% in 1950 to 23.7% in 2010, consistent with the impact of rapid urban and industrial development in China.

  2. Dynamics of CO2 partial pressure and CO2 outgassing in the lower reaches of the Xijiang River, a subtropical monsoon river in China.

    PubMed

    Yao, Guanrong; Gao, Quanzhou; Wang, Zhengang; Huang, Xiakun; He, Tong; Zhang, Yongling; Jiao, Shulin; Ding, Jian

    2007-04-15

    The partial pressure of carbon dioxide (pCO(2)) in surface water was surveyed monthly at 6 sampling sites along the entire length of the lower reaches of the Xijiang River, a subtropical monsoon river in China, and at the mouths of its major tributaries, over a whole hydrological year from April 2005 to March 2006, to reveal the seasonal and spatial dynamics of pCO(2). Intensive sampling and measurements were also conducted at Wuzhou gauge station in June and July to investigate the impact of floodwater on pCO(2) and to further explore the relationship between river discharge and pCO(2). The pCO(2) levels were well above atmospheric equilibrium (380 microatm) during the entire survey period with obvious seasonal and spatial variations, ranging from 600 microatm to 7200 microatm for the mainstream and from 700 to 11000 microatm for tributaries, respectively. The pattern of pCO(2) seasonal variation across 6 sites was almost consistent with each other with little difference. The pCO(2) levels in the dry season were relatively low, with relatively slight temporal and spatial fluctuations that were predominantly controlled by in situ biogenic activities. While the pCO(2) in the wet season greatly varied with river discharge, both annual maximum and minimum pCO(2) levels occurring in this period. The much higher pCO(2) in the early wet season were mainly induced by increasing baseflow and interflow that flushed significant soil CO(2) into the streams, whereas the lower pCO(2) observed after floods from July to September, some even lower than pCO(2) levels in the dry season, potentially resulted from in situ plankton blooms. The annual minima pCO(2) levels occurring in this period were caused by the dilution effect of floodwater. There was no obvious downstream trend in pCO(2) variation during the whole survey period, probably a consequence of disturbance from tributaries or spatially distinct channel characteristics and water environments. Based on measurements, we

  3. Feeding habits and habitats preferences affecting mercury bioaccumulation in 37 subtropical fish species from Wujiang River, China.

    PubMed

    Li, Sixin; Zhou, Lianfeng; Wang, Hongjun; Liang, Youguang; Chang, Jianbo; Xiong, Meihua; Zhang, Yichao; Hu, Juxiang

    2009-02-01

    The present study is the first to report the total mercury concentration of 37 fish species collected from Wujiang River, which is the largest branch on the southern bank of Yangtze River, China and proposed for hydropower development. Total mercury concentrations varied among the 37 subtropical species examined. We found higher mercury concentrations in carnivorous species demonstrating greater mercury bioaccumulation in species with more predatory feeding habits. There is no significant difference between fish grouped by habitat preference and feeding habit. However, carnivorous species preferring benthic positions had higher total mercury concentrations than others suggesting that mercury accumulation is related to the interaction of feeding habit and habitat preference. In our study, fish that are bottom living and feed on other fish or aquatic animals are more likely at high risk of mercury exposure. Additional mercury contamination and future impoundment may raise mercury concentration in fish in the Wujiang causing concern for human health and ecological impacts.

  4. Temporal trends of hydrocarbons in sediment cores from the Pearl River Estuary and the northern South China Sea.

    PubMed

    Peng, Xianzhi; Wang, Zhendi; Yu, Yiyi; Tang, Caiming; Lu, Hong; Xu, Shiping; Chen, Fanrong; Mai, Bixian; Chen, Shejun; Li, Kechang; Yang, Chun

    2008-11-01

    Concentrations and fluxes of unresolved complex mixture of hydrocarbons (UCM) and polycyclic aromatic hydrocarbons (PAHs) were analyzed for two (210)Pb dated sediment cores from the Pearl River Estuary (PRE) and the adjacent northern South China Sea (NSCS). Compound-specific stable carbon isotopic compositions of individual n-alkanes were also measured for identification of the hydrocarbon sources. The historical records of PAHs in the NSCS reflected the economic development in the Pearl River Delta during the 20th century. PAHs in the NSCS predominantly derive from combustion of coal and biomass, whereas PAHs in the PRE are a mixture of petrogenic and pyrogenic in origins. The isotopic profiles reveal that the petrogenic hydrocarbons in the PRE originate predominantly from local spillage/leakage of lube oil and crude oils. The accumulation rates of pyrogenic PAHs have significantly increased, whereas UCM accumulation has slightly declined in the NSCS in the recent three decades. PMID:18339464

  5. Mercury profiles in sediments of the Pearl River Estuary and the surrounding coastal area of South China.

    PubMed

    Shi, Jian-bo; Ip, Carman C M; Zhang, Gan; Jiang, Gui-bin; Li, Xiang-dong

    2010-05-01

    The spatial and temporal variations of mercury (Hg) in sediments of the Pearl River Estuary (PRE) and the surrounding coastal area (South China Sea) were studied. In surface sediments, the concentrations of Hg ranged from 1.5 to 201ng/g, with an average of 54.4ng/g, displaying a decreasing trend with the distance from the estuary to the open sea. This pattern indicates that the anthropogenic emissions from the Pearl River Delta (PRD) region are probably the main sources of Hg in this coastal region. Using the (210)Pb dating technique, the historical changes in the concentrations and influxes of Hg in the last 100 years were also investigated. The variations in Hg influxes in sediment cores obviously correlate with the economic development and urbanization that has occurred the PRD region, especially in the last three decades.

  6. Temporal trends of hydrocarbons in sediment cores from the Pearl River Estuary and the northern South China Sea.

    PubMed

    Peng, Xianzhi; Wang, Zhendi; Yu, Yiyi; Tang, Caiming; Lu, Hong; Xu, Shiping; Chen, Fanrong; Mai, Bixian; Chen, Shejun; Li, Kechang; Yang, Chun

    2008-11-01

    Concentrations and fluxes of unresolved complex mixture of hydrocarbons (UCM) and polycyclic aromatic hydrocarbons (PAHs) were analyzed for two (210)Pb dated sediment cores from the Pearl River Estuary (PRE) and the adjacent northern South China Sea (NSCS). Compound-specific stable carbon isotopic compositions of individual n-alkanes were also measured for identification of the hydrocarbon sources. The historical records of PAHs in the NSCS reflected the economic development in the Pearl River Delta during the 20th century. PAHs in the NSCS predominantly derive from combustion of coal and biomass, whereas PAHs in the PRE are a mixture of petrogenic and pyrogenic in origins. The isotopic profiles reveal that the petrogenic hydrocarbons in the PRE originate predominantly from local spillage/leakage of lube oil and crude oils. The accumulation rates of pyrogenic PAHs have significantly increased, whereas UCM accumulation has slightly declined in the NSCS in the recent three decades.

  7. Analysis of impacts of climate variability and human activity on streamflow for a river basin in northeast China

    NASA Astrophysics Data System (ADS)

    Zhang, Yongfang; Guan, Dexin; Jin, Changjie; Wang, Anzhi; Wu, Jiabing; Yuan, Fenghui

    2011-11-01

    SummaryHydrological processes in river systems have been changing under the impacts of both climate variability and human activities. The non-parametric Mann-Kendall statistic was used to identify change trends and points in the annual streamflow in the Hun-Tai River basin in northeast China. The identifications were based on streamflow records from six hydrological stations during 1961-2006, and the purpose was to analyze the change characteristics of the hydrological processes. The results indicated that all hydrological stations presented downward trends in annual streamflows. Abrupt changes in the annual streamflow occurred around 1978 in the Hun River basin, and around 1998 in the Taizi River basin. The impact of climate variability on the mean annual streamflow was also analyzed based on the relationships among streamflow, precipitation, and potential evapotranspiration. Precipitation and meteorological data from 22 rainfall stations and 10 weather stations within the basin were employed in the analysis. Daily potential evapotranspiration was calculated using the Penman-Monteith equation. Climate variability was estimated to account for 43% of the reduction in the annual streamflow, and human activities accounted for about 57%.

  8. 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.

  9. Occurrence and bioaccumulation of polybrominated diphenyl ethers in sediments and paddy ecosystems of Liaohe River Basin, northeast China.

    PubMed

    Ma, Xindong; Zhang, Haijun; Yao, Wenjun; Guo, Wen; Li, Depeng; Yao, Ziwei; Chen, Jiping

    2016-05-01

    Concentrations of 16 polybrominated diphenyl ether (PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms (crab, loach and carp) collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs (∑16PBDEs) in sediments and paddy soils were in the ranges of 273.4-3246.3pg/g dry weight (dw), and 192.1-1783.8pg/gdw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑16PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota-soil accumulation factor (BSAF) was calculated as the ratio between the lipid-normalized concentration in paddy-field organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab (3.6)>loach (3.3)>carp (2.1). BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their logKOW values was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern. PMID:27155431

  10. 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.

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

    PubMed

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

    2016-04-01

    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 COD(Cr) 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

  12. 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

  13. [Community structure and biological integrity of periphyton in Hunhe River water system of Liaoning Province, Northeast China].

    PubMed

    Yin, Xu-wang; Zhang, Yuan; Qu, Xiao-dong; Liu, Ying; Li, Qing-nan; Meng, Wei

    2011-10-01

    Taking the Hunhe River water system in Liaoning Province of Northeast China as a case, this paper investigated the community structure of periphyton and the physical and chemical characteristics of water environment at 62 sampling sites, and, by using the biological integrity index of periphyton (P-IBI) and the habitat environment quality index (QHEI), a health assessment on the aquatic ecosystem of the water system was conducted. There was a great spatial heterogeneity in the periphyton community structure, and the sampling sites could be divided into 4 groups, with significant differences in the community structure, species richness, density, and Shannon diversity index among the groups. Canonical correspondence analysis (CCA) showed that ammonia nitrogen (NH4(+)-N) and dissolved phosphorus (PO4(3-)-P) were the main water environment factors driving the formation of the periphyton community structure in the water system. The health assessment of the water system based on P-IBI and QHEI was basically in consistency, though the assessment of several reaches had large discrepancy. Overall, the Suzi River at the upper reaches of the water system had a better health status, while the upper reaches of Hunhe River and the main stream of Hunhe River at its middle and lower reaches were worse in health.

  14. An Analytical Solution of Groundwater Evapotranspiration in Arid Riparian Zone: A Case Study for the Tarim River in China

    NASA Astrophysics Data System (ADS)

    Cong, Z.; Dang, Q.; Wang, L.

    2012-12-01

    Groundwater evapotranspiration (ET) constitutes a major component of the water balance in arid riparian zone. Most of groundwater ET studies depend on numerical models but it is not easy to discuss the controling factors of groundwater ET in riparian zone. A two-dimension conceptal framework was set up to understand the groundwater ET in arid riparian zone. We deduced an analytical solution and its simplification of riparian ET based on a negative exponential relation between groundwater ET and groundwater depth. The groundwaer ET is controlled by soil type (soil hydraulic condontivity and parameter in the negative exponential relation), aquifer thickness, potential ET and river water table. Three soil types (sand, sandy loam and loam) with different soil texture were selected to discuss the riparian ET and it was found that the riaprian ET is similar for different soil type. The framework and analytical solution are applied in Tarim River in China where a river restoration project had been put into practice. The discussions are helpful to design water supply pattern of river restoration.

  15. Contamination characteristics, ecological risk and source identification of trace metals in sediments of the Le'an River (China).

    PubMed

    Chen, Haiyang; Chen, Ruihui; Teng, Yanguo; Wu, Jin

    2016-03-01

    Recognizing the pollution characteristics of trace metals in river sediments and targeting their potential sources are of key importance for proposing effective strategies to protect watershed ecosystem health. In this study, a comprehensive investigation was conducted to identify the contamination and risk characteristics of trace metals in sediments of Le'an River which is a main tributary of the largest freshwater lake in China, Poyang Lake. To attain this objective, several tools and models were considered. Geoaccumulation index and enrichment factor were used to understand the general pollution characteristic of trace metals in sediments. Discriminant analysis was applied to identify the spatial variability of sediment metals. Sediment quality guidelines and potential ecological risk index were employed for ecological risk evaluation. Multivariate curve resolution-alternating least square was proposed to extract potential pollution sources, as well as the application of Monte-Carlo simulation for uncertainty analysis of source identification. Results suggested that the sediments in Le'an River were considerably polluted by the investigated trace metals (Cd, Cr, As, Hg, Pb, Cu, Zn and Ni). Sediment concentrations of these metals showed significant spatial variations. The potential ecological risk lay in high level. Comparatively speaking, the metals of Cd, Cu and Hg were likely to result in more harmful effects. Mining activities and the application of fertilizers and agrochemicals were identified as the main anthropogenic sources. To protect the ecological system of Le'an River and Poyang Lake watershed, industrial mining and agricultural activities in this area should to be strictly regulated.

  16. 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

  17. 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

  18. Distribution of polybrominated diphenyl ethers in sediments of the Pearl River Delta and adjacent South China Sea.

    PubMed

    Mai, Bixian; Chen, Shejun; Luo, Xiaojun; Chen, Laiguo; Yang, Qingshu; Sheng, Guoying; Peng, Pingan; Fu, Jiamo; Zeng, Eddy Y

    2005-05-15

    Spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs) in sediments of the Pearl River Delta (PRD) and adjacent South China Sea (SCS) of southern China were examined. A total of 66 surface sediment samples were collected and analyzed to determine the concentrations of 10 PBDE congeners (BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209). The concentrations of BDE-209 and SigmaPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) ranged from 0.4 to 7340 and from 0.04 to 94.7 ng/g, respectively. The SigmaPBDEs concentrations were mostly < 50 ng/g, within the range for riverine and coastal sediments around the world, whereas the BDE-209 concentrations at the most contaminated sites were at the high end of the worldwide figures. Congener compositions were dominated by BDE-209 (72.6 - 99.7%), with minor contributions from penta- and octa-BDEs. Slightly different PBDE compositions were observed among samples collected from different locations, attributable to possible decomposition of highly brominated congeners and/or redistribution between particles of various sizes during atmospheric or fluvial transportation. The PBDE patterns in the SCS and Pearl River Estuary sediments were similar to those in sediments of the Zhujiang and Dongjiang Rivers, reflecting the widespread influence from local inputs. Analyses of two short sediment cores collected from the Pearl River Estuary showed that concentrations of BDE-209 rapidly increased in the upper layers of both cores, coincident with the growth of the electronics manufacturing capacities in the PRD region. The major sources of PBDEs were probably waste discharges from the cities of Guangzhou, Dongguan, and Shenzhen, the three fastest growing urban centers in the PRD.

  19. Concentrations and inventories of polycyclic aromatic hydrocarbons and organochlorine pesticides in watershed soils in the Pearl River Delta, China.

    PubMed

    Ma, Xiaoxuan; Ran, Yong; Gong, Jia