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Sample records for pearl river basin

  1. Geohydrologic summary of the Pearl River basin, Mississippi and Louisiana

    USGS Publications Warehouse

    Lang, Joseph W.

    1972-01-01

    Fresh water in abundance is contained in large artesian reservoirs in sand and gravel deposits of Tertiary and Quaternary ages in the Pearl River basin, a watershed of 8,760 square miles. Shallow, water-table reservoirs occur in Quarternary deposits (Pleistocene and Holocene) that blanket most of the uplands in .the southern half of the basin and that are present in smaller upland areas and along streams elsewhere. The shallow reservoirs contribute substantially to dry-weather flow of the Strong River and Bogue Chitto and of Holiday, Lower Little, Silver, and Whitesand Creeks, among others. About 3 billion acre-feet of ground water is in storage in the fresh-water section, which extends from the surface to depths ranging from about sea level in the extreme northern part of the basin to more than 3,000 feet below sea level in the southern part of the basin. Variations in low flow for different parts of the river basin are closely related to geologic terrane and occurrence of ground water. The upland terrace belt that crosses the south-central part of the basin is underlain by permeable sand and gravel deposits and yields more than 0.20 cubic feet per second per square mile of drainage area to streamflow, whereas the northern part of the basin, underlain by clay, marl, and fine to medium sand, yields less than 0.05 cubic feet per second per square mile of drainage area (based on 7-day Q2 minimum flow computed from records). Overall, the potential surface-water supplies are large. Because water is available at shallow depths, most of the deeper aquifers have not been developed anywhere in the basin. At many places in the south, seven or more aquifers could be developed either by tapping one sand in each well or by screening two or more sands in a single well. Well fields each capable, of producing several million gallons of water a day are feasible nearly anywhere in the Pearl River basin. Water in nearly all the aquifers is of good to excellent quality and requires

  2. Streamflow analysis of the Apalachicola, Pearl, Trinity, and Nueces River basins, southeastern United States

    USGS Publications Warehouse

    Greene, K.E.; Slade, R.M., Jr.

    1995-01-01

    Annual mean and annual minimum and maximum daily mean streamflow were compared with associated annual index precipitation for sites on the main channel and tributaries of the Apalachicola, Pearl, Trinity, and Nueces Rivers in the Gulf of Mexico Basin. Precipitation and annual minimum streamflow at the downstream station on each river increased over the available periods of record. No long-term changes were identified in mean and maximum streamflow to the Gulf from the Apalachicola River Basin. Annual mean and maximum streamflow to the Gulf increased with time from the Pearl River Basin and decreased from the Trinity River Basin. Annual mean streamflow showed varied trends and annual maximum streamflow decreased for the Nueces River Basin. Short-term trends in streamflow and precipitation generally corresponded at most stations. Total reported surface-water withdrawals from the Trinity River Basin increased more than fourfold since 1940 and currently represent about one-fourth of the mean streamflow near the mouth of the river. Total reported withdrawals from the Nueces River Basin increased more than eightfold since 1940 and currently represent about one-third of the annual mean streamflow near the mouth. Predicted peak streamflow into the Gulf from the Apalachicola River was 23 percent less for the 50-year peak streamflow after reservoirs were constructed. Annual mean streamflow to the Gulf was reduced following construction of the downstream reservoirs on the Apalachicola and Trinity Rivers. Peak streamflows from the Pearl and Trinity Rivers have not been affected. The annual mean streamflow from the Nueces River was reduced by about 24 percent as a result of filling and evaporation at Choke Canyon Reservoir.

  3. 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.

  4. Transitional properties of droughts and related impacts of climate indices in the Pearl River basin, China

    NASA Astrophysics Data System (ADS)

    Xiao, Mingzhong; Zhang, Qiang; Singh, Vijay P.; Liu, Lin

    2016-03-01

    Drought is the natural hazard poorly understood so far due to various mechanisms behind. Moreover, disastrous effects of drought on human society necessitate accurate forecasting of drought behaviors. In this case, to improve forecasting of drought in the Pearl River basin, a trivariate copula model has been developed and used to include the El Nino Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian Ocean Dipole (IOD) and Pacific Decadal Oscillation (PDO) into model structure of Markov chain. The Standardized Precipitation Evapotranspiration Index (SPEI) has been used to monitor the drought in this study. Comparison with the preliminary correlation analysis between each month climate index and SPEI series indicated that the trivariate copula performs satisfactorily well in evaluation of influences of climate indices on the transition probabilities of drought. It is considered that the region with the negative vertical velocity is dominated by more precipitation and vice versa. Moreover, field patterns of 500 hPa vertical velocity anomalies related to each climate index have further corroborated the influences of climate indices on the drought behaviors. Besides, the mean extreme drought durations under different conditions of each climate index have also been investigated in this study. Results indicated that the mean extreme drought duration tends to be longer in the western part of the Pearl River basin during positive phase of ENSO while tends to be shorter during the positive phase of NAO and vice versa; in the central part of the Pearl River basin, the mean extreme drought duration tends to be shorter during the positive phase of ENSO, NAO and PDO while tends to be longer during the positive episode of IOD, and vice versa; in the eastern part of the Pearl River basin, the mean extreme drought duration tends to be shorter during the positive episode of ENSO and PDO, and vice versa. This study sheds new light on transitional behaviors of

  5. Stationarity of annual flood peaks during 1951-2010 in the Pearl River basin, China

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Xiao, Mingzhong; Xu, Chong-Yu

    2014-11-01

    The assumption of stationarity of annual peak flood (APF) records at 28 hydrological stations across the Pearl River basin, China, is tested. Abrupt changes in mean and variance are tested using the Pettitt technique and the Loess method. Trends of APFs are analyzed using the Mann-Kendall method and the Spearman technique. And then the stationarity of the APF series is further investigated by GAMLSS models and long-term persistence. Results indicate that: (1) abrupt changes in mean and variance have similar influences on the changing properties of APFs, such as stationarity. Abrupt changes in mean and variance are only field significant in the East River basin; (2) the change points have a considerable impact on the detection of trends, and these may be attributed to the fact that a abrupt increase or decrease in mean values will affect the trend variations. Besides, for the APF series being free of change points and trend, the GAMLSS models also corroborate stationarity of the APF series; (3) the nonstationarity in the Pearl River basin is mainly due to the existence of the change point. However, the APF series with change points in mean and/or variance are also characterized by long-term persistence, and thus it is infeasible to assert that the abrupt behaviors and/or trends of the APF series are the result of human activities or long-term persistence, especially in the East River basin. Results of this study will provide information for management of water resources and design of hydraulic facilities in the Pearl River basin in a changing environment.

  6. A historical perspective of river basin management in the Pearl River Delta of China.

    PubMed

    Weng, Qihao

    2007-12-01

    Three innovations in water and soil conservancy technology in the Pearl River Delta of South China, i.e., dike building, land reclamation, and dike-pond systems, were examined from a historical perspective. They were found to best reflect local farmers' efforts to cope with the challenges of various water disasters and to build a harmonious relationship with the changed environment. These technologies were critical to the agricultural success and sustainability over the past 2000 years, and reflected local farmers' wisdom in balancing land use and environmental conservation. Imprudent use of a new agricultural technology could damage the environment, and could disturb the human-environment relationship, as evidenced by the more frequent flooding that followed inappropriate dike building and premature reclamation. It is suggested that as the urbanization and industrialization process in the delta region continues, the kind of thinking that made the water and soil conservancy sustainable needs to be incorporated into the design of similar technologies for water use and river basin management today. PMID:17240525

  7. Spatiotemporal characteristics of precipitation changes in the Pearl River Basin, China

    NASA Astrophysics Data System (ADS)

    Liu, Bingjun; Chen, Junfan; Lu, Wenxiu; Chen, Xiaohong; Lian, Yanqing

    2016-02-01

    The change structures of precipitation and precipitation intensity and rainy days are analyzed for the Pearl River Basin (from 1959 to 2009) on the basis of a suite of 24 climatic indices derived from daily precipitation data at 62 meteorological stations with the help of the Mann-Kendall test. Contributions of seasonal precipitation and precipitation intensity class to the annual precipitation are also examined using the inverse distance weighted method. The following four conclusions can be drawn: (1) although the average annual precipitation of the entire basin does not show obvious variation, the number of annual rainy days has decreased significantly in 98.3 % of the stations. These two factors result in an obvious increase in precipitation intensity at 64.5 % of the stations. (2) No clear change trend has been found for seasonal precipitation over the entire area; however, the number of rainy days in each season has decreased significantly. In particular, the number of rainy days in the entire year and in the fall season has decreased in 98.3 and 100 % of the stations, respectively. (3) Although the number of rainy days in drizzle has decreased in 83.9 % of the stations, the number of rainy days where heavy rain and extremely heavy rain occurred increased in nearly 75.8 and 82.3 % of the stations, respectively. (4) The number of rainy days in fall and winter contributes more to the change in the number of annual rainy days than the number of rainy days in spring and summer. Heavy rain and extremely heavy rain contribute more to the change in total annual precipitation than drizzle; however, they contribute less to the change in the number of annual rainy days than drizzle. The findings in this study can provide important information for formulating water resource and eco-environment management strategies in the Pearl River Basin to policymakers and stakeholders.

  8. 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.

  9. Sediment flux history of Pearl River mouth basin, North margin of South China Sea

    NASA Astrophysics Data System (ADS)

    Wu, S.

    2004-12-01

    This work estimates the solid sediment flux in Pearl River mouth basin from Cenozoic (42Ma). The estimates were derived from isopach maps, seismic reflection profiles and drill holes. Average solid sediment fluxes were calculated for six epochs approximately corresponding to geological periods: Eocene-Lower Oligocene (42-29.3), Upper Oligocene (29.3-23.8), Lower Miocene (23.8-16.4), Middle Miocene (16.4-11.2), Upper Miocene (11.2-5.32), and Pliocene-Pleistocene (5.32-0). The total sediment flux from 42 Ma is 392071.3 km3 and 0.89 km of erosion formed from the onshore drainage basin area. The average erosion rate is 22 m/ Ma. The sediment flux curve shows 3 episodes massive increase in sediment supply, i.e. Upper Oligocene, Middle Miocene and Pliocene-Pleistocene. The first increase related to the break up activity and is the product of elevated rift shoulder. The other two increase peak link to the changing of climate.

  10. Petroleum systems of Zhu III depression in Pearl River Mouth Basin, South China Sea

    SciTech Connect

    Weilin, Zhu; Li Mingbi; Wu Peikang )

    1996-01-01

    Zhu III depression is located in the west part of Pearl River Mouth Basin, and covers an area of 11,000 sq km. Until now more than twenty wells have been drilled in the depression and its surrounding area, and all oil-gas fields and oil-gas discoveries are concentrated inside the depression. Integrated study indicates that there are two petroleum systems in Zhu III depression. One is Wenchang - Zhuhai, Zhujiang oil system which is mainly distributed in Wenchang B sag in the southwest part of the depression. Its source rock, the Wenchang formation is mainly composed of dark mudstone of lacustrine facies, with thicknesses up to more than 1000 m. Its reservoir includes tidal sandstone of transitional facies of Zhuhai formation and neritic sandstone of the lower part of Zhujiang formation. Through bounding faults and margin coarse sediment zone, oil generated from the Wenchang formation migrated into overlying sandstone of Zhuhai formation, which was overlaid by mudstone beds of bay facies of Zhuhai formation or neritic facies of Zhujiang formation, and formed oil accumulations. The other system is Enping - Zhuhai gas system, distributed in Wenchang A sag in the northeast part of the depression, whose source rock in the Enping formation deposited in the contracting stage of the lake, dominated by swamp coal measure in lithology and terrestrial plant clastics in kerogen components. The gas generated from Enping formation directly migrated into overlying tidal sandstone of Zhuhai formation and formed gas accumulations. Therefore, exploration in Wenchang A sag in the northeast part of the depression is for gas accumulations, and oil accumulations in Wenchang B sag in the southwest part of the depression, while oil-gas mixed accumulations are likely to be found in the transitional area of two systems.

  11. Petroleum systems of Zhu III depression in Pearl River Mouth Basin, South China Sea

    SciTech Connect

    Weilin, Zhu; Li Mingbi; Wu Peikang

    1996-12-31

    Zhu III depression is located in the west part of Pearl River Mouth Basin, and covers an area of 11,000 sq km. Until now more than twenty wells have been drilled in the depression and its surrounding area, and all oil-gas fields and oil-gas discoveries are concentrated inside the depression. Integrated study indicates that there are two petroleum systems in Zhu III depression. One is Wenchang - Zhuhai, Zhujiang oil system which is mainly distributed in Wenchang B sag in the southwest part of the depression. Its source rock, the Wenchang formation is mainly composed of dark mudstone of lacustrine facies, with thicknesses up to more than 1000 m. Its reservoir includes tidal sandstone of transitional facies of Zhuhai formation and neritic sandstone of the lower part of Zhujiang formation. Through bounding faults and margin coarse sediment zone, oil generated from the Wenchang formation migrated into overlying sandstone of Zhuhai formation, which was overlaid by mudstone beds of bay facies of Zhuhai formation or neritic facies of Zhujiang formation, and formed oil accumulations. The other system is Enping - Zhuhai gas system, distributed in Wenchang A sag in the northeast part of the depression, whose source rock in the Enping formation deposited in the contracting stage of the lake, dominated by swamp coal measure in lithology and terrestrial plant clastics in kerogen components. The gas generated from Enping formation directly migrated into overlying tidal sandstone of Zhuhai formation and formed gas accumulations. Therefore, exploration in Wenchang A sag in the northeast part of the depression is for gas accumulations, and oil accumulations in Wenchang B sag in the southwest part of the depression, while oil-gas mixed accumulations are likely to be found in the transitional area of two systems.

  12. Origin and occurrence of crude oils in the Zhu1 sub-basin, Pearl River Mouth Basin, China

    NASA Astrophysics Data System (ADS)

    Hu, Yue; Hao, Fang; Zhu, Junzhang; Tian, Jinqiang; Ji, Yubing

    2015-01-01

    The origin of the seventeen major oil fields in the Zhu1 sub-basin, Pearl River Mouth Basin (PRMB) was studied based on the results of Rock-Eval pyrolysis on more than 370 samples and biomarker analysis on 31 source rock samples and 63 oil samples. The two possible source rock intervals have different biomarker assemblages and were deposited in different environments. The Wenchang Formation (E2w, 56.5-32 Ma) is characterized mainly by low C19/C23 tricyclic terpane (<2.0), low C24 tetracyclic terpane/αβC30 hopane (<0.06), low bicadinane-T/αβC30 hopane (<2.0) and high 4-methyl steranes/∑C29 steranes (most >0.4) ratios, and were deposited in anoxic to suboxic environments with important contribution from Pediastrum and Dinoflagellates. The Enping Formation (E3e, 32-30 Ma) has high C19/C23 tricyclic terpane, high C24 tetracyclic terpane/αβC30 hopane, widely variable yet overally high bicadinane-T/αβC30 hopane and low 4-methyl steranes/∑C29 steranes ratios, and were deposited in freshwater lacustrine to swamp conditions with significant terrigenous organic matter input. According to oil-source correlation, three oil classes can be identified in the Zhu1 sub-basin. Class 1 oil is E2w-derived and occurs widely. Class 2 oil is E3e-derived and refers to oils from F field in the north of the Huizhou depression. Class 3 oil is a mixture of oils generated from E2w and E3e, only distributed in the Huizhou depression and on its southern margin. The petroleum distribution pattern is mainly controlled by the distribution of source rocks and the migration pathways of oils. This research has important implications for future exploration.

  13. A geochemical investigation of crude oils from Eastern Pearl River Mouth Basin, South China Sea

    NASA Astrophysics Data System (ADS)

    Jiamo, Fu; Cunmin, Pei; Guoying, Sheng; Dehan, Liu; Sizhong, Chen

    A thorough petroleum exploration of the Pearl River Mouth Basin (PRMB), South China Sea, began in 1983. At present, several oilfields have been found in the PRMB, mainly distributed in Dongsha Massif, Huizhou and Xijiang Depressions as well as Huilu Lowhigh, and one of them has been developed recently. The crude oils found in the basin can be classified into two types. One is normal waxy type, and the other is cyclic type, which may be caused by minor biodegration and is restricted to the Liuhua District of Dongsha Massif. However, on the basis of geochemical characteristics, all the crude oils are thermally mature, indicating that they are derived from source rocks which have entered the main oil generation period but their maturity is not high enough to reach the overmature stage. Moreover, in the biomarker distribution, the oils also share many similarities. Almost all the oils contain abundant C 30 4-methylsteranes with 24-ethyl side chain, ubiquitous oleanane and lower concentration of gammacerane, and possess high ratios of Ni/V, pristane to phytane and C 30 hopane over total C 29 steranes as well as high paraffin wax and low sulphur content, indicating that they originated from terrestrial organic matter deposited in lacustrine and marsh coal-forming environments. However, some characteristics resemble Brazilian offshore oils of salinewater lacustrine environment. The oils found in the PRMB can also be classified into three main genetic types based on the relative values of pristane over phytane ratio, C 29 sterane preference and the composition of the carbon isotope. Type I oils occurred in the Huizhou and the Xijiang Depressions and their adjacent Dongsha Massif. It has higher ratios of pristane to phytane (1.80-5.54 and 3.21 on the average scale) and heavier carbon isotopic composition, indicating that their source rocks contain much more abundant terrestrial higher plant input. Type II, encountered in Huilu Lowhigh and its bounding area of Dongsha Massif

  14. Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

    USGS Publications Warehouse

    Wang, Xiujuan; Qiang, Jin; Collett, Timothy S.; Shi, Hesheng; Yang, Shengxiong; Yan, Chengzhi; Li, Yuanping; Wang, Zhenzhen; Chen, Duanxin

    2016-01-01

    A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly acquired 3D seismic data volume. High-amplitude reflections just above the bottom-simulating reflectors (BSRs) were interpreted to be associated with the accumulation of gas hydrate with elevated saturations. Enhanced seismic reflections below the BSRs were interpreted to indicate the presence of free gas. The base of the BGHSZ was established using the occurrence of BSRs. In areas absent of well-developed BSRs, the BGHSZ was calculated from a model using the inverted P-wave velocity and subsurface temperature data. Seismic attributes were also extracted along the BGHSZ that indicate variations reservoir properties and inferred hydrocarbon accumulations at each site. Gas hydrate saturations estimated from the inversion of acoustic impedance of conventional 3D seismic data, along with well-log-derived rock-physics models were also used to estimate gas hydrate saturations. Our analysis determined that the gas hydrate petroleum system varies significantly across the Pearl River Mouth Basin and that variability in sedimentary properties as a product of depositional processes and the upward migration of gas from deeper thermogenic sources control the distribution of gas hydrates in this basin.

  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. The geochemistry characteristic and dating of cold seepage carbonates of the Pearl River Mouth Basin, eastern of South China Sea

    NASA Astrophysics Data System (ADS)

    Fang, Yunxin; Fu, Shaoying

    2015-04-01

    Cold seepage carbonates are usually formed by the interaction of methane oxidizing archaea, sulfate reducing bacteria and cold seepage which contain abundant venting hydrocarbon gases. The presence of cold seepage carbonates on the seabed is one of the evidences that the area exist venting hydrocarbon gases, which are usually result by the dissociation of gas hydrate. The cold seepage property and fluid flow rate can influence the oxidation-deoxidation environment of the bottom water and sediment. Many previous studies focused on the mineral composition, microstructure, elemental composition, isotope composition of the cold seepage carbonates and isotopic dating for the cold seepage carbonates. The isotopic dating for the cold seepage carbonates can provide the information of the gas hydrate formation and dissociation in some area of the South China Sea. High precision TIMS-U dating and 14C dating are used as routine method for the dating of the Quaternary carbonates and fossils. The cold seepage carbonates in the study include the samples collected by ROV on the seabed and the drilling for gas hydrate in the Pearl River Mouth Basin, eastern of the South China Sea. The authigenic carbonate occurred in different depth in the A, B and C drilling site. They may be represent different events of gas hydrate formation and dissociation in the Quaternary. The dating study for all the cold seepage carbonates can provide the relative accurate eras of the gas hydrate dissociation events in certain area of the South China Sea.

  17. 33 CFR 117.683 - Pearl River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Pearl River. 117.683 Section 117.683 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Mississippi § 117.683 Pearl River. See § 117.486, Pearl...

  18. 33 CFR 117.683 - Pearl River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pearl River. 117.683 Section 117.683 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Mississippi § 117.683 Pearl River. See § 117.486, Pearl...

  19. 33 CFR 117.683 - Pearl River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Pearl River. 117.683 Section 117.683 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Mississippi § 117.683 Pearl River. See § 117.486, Pearl...

  20. 33 CFR 117.683 - Pearl River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pearl River. 117.683 Section 117.683 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Mississippi § 117.683 Pearl River. See § 117.486, Pearl...

  1. 33 CFR 117.683 - Pearl River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pearl River. 117.683 Section 117.683 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Mississippi § 117.683 Pearl River. See § 117.486, Pearl...

  2. 33 CFR 117.486 - Pearl River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pearl River. 117.486 Section 117.486 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.486 Pearl River. (a) The draw of the...

  3. 33 CFR 117.486 - Pearl River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pearl River. 117.486 Section 117.486 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.486 Pearl River. (a) The draw of the...

  4. 33 CFR 117.486 - Pearl River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Pearl River. 117.486 Section 117.486 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.486 Pearl River. (a) The draw of the...

  5. 33 CFR 117.486 - Pearl River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pearl River. 117.486 Section 117.486 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.486 Pearl River. (a) The draw of the...

  6. 33 CFR 117.486 - Pearl River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Pearl River. 117.486 Section 117.486 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.486 Pearl River. (a) The draw of the...

  7. Mesozoic deformation in the Chaoshan Depression of the Pearl River Mouth Basin, northern South China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Jiangyang; Sun, Zhen; Zhang, Yunfan; Li, Fucheng

    2016-05-01

    Newly collected, high resolution multi-beam sonar data are combined with previous bathymetry data to produce an improved bathymetric map of Shatsky Rise oceanic plateau. Bathymetry data show that two massifs within Shatsky Rise are immense central volcanoes with gentle flank slopes declining from a central summit. Tamu Massif is a slightly elongated, dome-like volcanic edifice; Ori Massif is square shaped and smaller in area. Several down-to-basin normal faults are observed on the western flank of the massifs but they do not parallel the magnetic lineations, indicating that these faults are probably not related to spreading ridge faulting. Moreover, the faults are observed only on one side of the massifs, which is contrary to expectations from a mechanism of differential subsidence around the massif center. Multi-beam data show many small secondary cones with different shapes and sizes that are widely-distributed on Shatsky Rise massifs, which imply small late-stage magma sources scattered across the surface of the volcanoes in the form of lava flows or explosive volcanism. Erosional channels occur on the flanks of Shatsky Rise volcanoes due to mass wasting and display evidence of down-slope sediment movement. These channels are likely formed by sediments spalling off the edges of summit sediment cap.

  8. The mechanism of post-rift fault activities in Baiyun sag, Pearl River Mouth basin

    NASA Astrophysics Data System (ADS)

    Sun, Zhen; Xu, Ziying; Sun, Longtao; Pang, Xiong; Yan, Chengzhi; Li, Yuanping; Zhao, Zhongxian; Wang, Zhangwen; Zhang, Cuimei

    2014-08-01

    Post-rift fault activities were often observed in deepwater basins, which have great contributions to oil and gas migration and accumulation. The main causes for post-rift fault activities include tectonic events, mud or salt diapirs, and gravitational collapse. In the South China Sea continental margin, post-rift fault activities are widely distributed, especially in Baiyun sag, one of the largest deepwater sag with its main body located beneath present continental slope. During the post-rift stage, large population of faults kept active for a long time from 32 Ma (T70) till 5.5 Ma (T10). Seismic interpretation, fault analysis and analogue modeling experiments indicate that the post-rift fault activities in Baiyun sag between 32 Ma (T70) and 13.8 Ma (T30) was mainly controlled by gravity pointing to the Main Baiyun sag, which caused the faults extensive on the side facing Main Baiyun sag and the back side compressive. Around 32 Ma (T70), the breakup of the continental margin and the spreading of the South China Sea shed a combined effect of weak compression toward Baiyun sag. The gravity during post-rift stage might be caused by discrepant subsidence and sedimentation between strongly thinned sag center and wing areas. This is supported by positive relationship between sedimentation rate and fault growth index. After 13.8 Ma (T30), fault activity shows negative relationship with sedimentation rate. Compressive uplift and erosion in seismic profiles as well as negative tectonic subsiding rates suggest that the fault activity from 13.8 Ma (T30) to 5.5 Ma (T10) might be controlled by the subductive compression from the Philippine plate in the east.

  9. The depositional characteristics and oil potential of paleo Pearl river delta systems in the Pearl river mouth basin, South China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Jishu; Xu, Shice; Sang, Jinyu

    1994-07-01

    Delta systems in the Zhuhai, Zhujiang and Hanjiang formations are interpreted as having formed during periods of sea-level rise from the late Oligocene to mid-Miocene (30-10.5 My B.P.). Deltas in the Zhuhai Formation were developed in a shallow water environment on a sandy, wave- or fluvial-dominated coasts. Thick and blanket-like sandstones are common but mudstones are infrequent. Oil-bearing zones have been found only in the upper part of the systems, overlain by mudstone of the Zhujiang Formation. Deltas in the Zhujiang Formation are interpreted as having formed in a deeper water environment on sandy, wave- or fluvial-dominated coasts. Carbonate platforms started growing on the Dongsha massif as the sea-level slowly rose. The moderate sandstone/mudstone ratio in the delta systems and a zone of secondary porosity in the carbonate rocks provide an excellent reservoir rock and seal rock for the basin. Deltas in the Lower Hanjiang Formation are similar to those of the Zhujiang Formation, but the upper part of the Formation is interpreted as having formed in a shelf environment; the thick shelf mudstone, interbedded with offshore bar sandstones, would be one of the better regional seal rocks in the study area. No carbonate rock developed on the Dongsha massif due to the rapid rise in sea-level. All delta systems from the Zhuhai to the Zhujiang Formation are stacked in an onlap pattern indicating a more and more expanding marine transgression, which was caused by eustatic sea-level rise. This marine transgression is almost unique and contrasts to the progradational (offlap) pattern of Cenozoic delta systems in the Gulf of Mexico. It resulted in thick sandstone deposits, immature or poorly mature source rock and no ductile mudstones, with no growth faults or rollover structures. Hydrocarbons generated from Eocene-Oligocene lacustrine source rocks are trapped by drape structures related to local basement highs or by carbonate rock with secondary porosity. Most of the

  10. Development of Paleogene depressions and deposition of Lacustrine source rocks in the Pearl River Mouth basin, northern margin of the South China Sea

    SciTech Connect

    Wang, Chunxiu; Sun, Yuxiao

    1994-11-01

    A more accurate, integrated chronostratigraphic framework is applied to the analysis of the development of Paleogene depressions in the Pearl River Mouth basin. The results of our study show that the development of these depressions was characterized by at least three rifting or basin-forming phases occurring during these periods: late Paleocene (Late Cretaceous?)-middle Eocene, late Eocene-early Oligocene, and middle-Oligocene-late Oligocene. The transition from rifting stage to postrifting stage in the basin is about 10 m.y. later than the initial spreading of the South China Sea. The prologue of the spreading of the South China Sea began as early as the end of the middle Eocene. Lacustrine source rocks deposited during the basin`s first rifting phase are thick and of good quality; source rocks deposited during the last two phases, which had a sharp increase in sedimentation rate, are of lesser quality, with the exception being those areas where deposits were out of reach of sediment from the northern mainland.

  11. Investigation of Pearl River data collection system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The reliability of employing NASA developed remote sensing for in situ near real time monitoring of water quality in the Pearl River is evaluated. The placement, operation and maintenance of a number of NASA developed data collection platforms (DCP's) on the Pearl River are described. The reception, processing, and retransmission of water quality data from an ERTS satellite to the Mississippi Air and Water Pollution Control Commission (MAWPCC) via computer linkup are assessed.

  12. A comparative study on riverine DOC export fluxes from the Mississippi River and Pearl River (Invited)

    NASA Astrophysics Data System (ADS)

    Guo, L.; Zhou, Z.

    2013-12-01

    River carbon export fluxes represent a major component in marine carbon budge, affecting water quality, carbon dynamics, and biogeochemical processes in coastal marine environments. Quantitative determination of composition, transformation and export fluxes of carbon species from rivers is thus essential. Using our time series data, we examined riverine chromophoric-DOM composition, carbon yields, and DOC export fluxes between two contrasting river systems: the Mississippi River, a large river with extensive anthropogenic impact, and the Pearl River, a small blackwater river with cypress swamps in the lower basin. Compared to the Pearl River, DOM in the lower Mississippi River exhibited lower aromaticity and lower chromophoric-DOM abundance with low seasonal variability, but higher protein-type fluorophores and non-CDOM components, indicating the effects of prolonged water residence time, increased in situ production, and enhanced photochemical degradation in the Mississippi River. Protein-like CDOM components decreased with increasing discharge, showing dilution effect during high flow. In addition to higher bulk DOM abundance and higher aromaticity, Pearl River waters contained higher high-molecular-weight (HMW) DOM with higher seasonal variability. The drainage area in the Mississippi River basin is ~140 times as large as that in the Pearl River, with ~70 times its freshwater discharge. Nevertheless, annual DOC export fluxes (in g-C/yr) into the Gulf of Mexico and DOC yield (in g-C/m2/yr) from the Mississippi River basin were only 28 times and 0.3 times of those of the Pearl River. Small rivers with higher forest and swamp in the lower basin may play an important role in riverine carbon export, contributing higher aromatic DOM and HMW-DOM components into marine environments.

  13. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  14. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  15. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  16. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  17. Partners in Leadership for Pearl River

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Members of the 2007 class of Partners in Leadership toured NASA Stennis Space Center in Hancock County, Miss., on Jan. 11. They visited the center's B Test Stand, part of the center's rocket engine test complex. The Partners in Leadership training program is designed to teach Pearl River County leaders about their county's government, economic development, health and human services, history and arts, environment and education during a 10-month period. The program, sponsored by the Partners for Pearl River County, helps fulfill the mission of the economic and community development agency.

  18. Comprehensive Assessment Report, Pearl River School District.

    ERIC Educational Resources Information Center

    Pearl River Union Free School District, NY.

    The 1986 Comprehensive Assessment Report on the Pearl River (New York) Public School District describes the district's 1,807-student population (grades K through 12), the community, and its schools. Tables provide data on: (1) students' performance on standardized tests, including the California Achievement/Aptitude Tests; New York State Pupil…

  19. Application of sequence stratigraphy to exploration and development in eastern Pearl River Mouth Basin, South China Sea

    SciTech Connect

    Yang, Shaokun; Huang Lifen; Xu Shice

    1996-12-31

    Some appropriate conditions for applying sequence stratigraphy in PRMB exist: (1) The PRMB is a Cenozoic extension basin with weak tectogenesis after rifting; (2) The late Tertiary successive sediments deposited over the area from coast to deep marine basin are well developed and their seismic reflection is good in quality; (3) High resolution quantitative biostratigraphy has provided more precise data of eustasy. Twenty-two third order sequences since 30Ma were identified and are correlative to global cycle chart, but TB2.1 can be further divided into two third-order sequences. The 22 sequences from a {open_quote}retrograding stacking pattern{close_quote} which resulted in no large constructive delta or delta-related rollover anticlines. However, widely deposited seal rock possibly sealed the incised-valley, basin floor fan (BPF), and transgressive sandstone to form valid stratigraphic traps. Stratigraphic traps are particularly important in future exploration because of poor anticline trap types in the basin. Some ER stratigraphic traps can be predicted after studying the distribution of systems ER tracts in each sequence as a basic exploration unit. The BPF of TB2.1 which is closed to the source kitchen area could form a large subtle trap. Using the parasequence as a basic unit in reservoir scale will provide a new method to discover new reservoirs. For example, new oil reserves within the predicted stratigraphic trap related to K22, which can be divided into several parasequences in C.A. 16/08, were obtained after drilling. Sequence stratigraphy has become a valid high resolution tool for chronostratigraphic correlation and fine-division and exploration of stratigraphic traps.

  20. Application of sequence stratigraphy to exploration and development in eastern Pearl River Mouth Basin, South China Sea

    SciTech Connect

    Yang, Shaokun; Huang Lifen; Xu Shice

    1996-01-01

    Some appropriate conditions for applying sequence stratigraphy in PRMB exist: (1) The PRMB is a Cenozoic extension basin with weak tectogenesis after rifting; (2) The late Tertiary successive sediments deposited over the area from coast to deep marine basin are well developed and their seismic reflection is good in quality; (3) High resolution quantitative biostratigraphy has provided more precise data of eustasy. Twenty-two third order sequences since 30Ma were identified and are correlative to global cycle chart, but TB2.1 can be further divided into two third-order sequences. The 22 sequences from a [open quote]retrograding stacking pattern[close quote] which resulted in no large constructive delta or delta-related rollover anticlines. However, widely deposited seal rock possibly sealed the incised-valley, basin floor fan (BPF), and transgressive sandstone to form valid stratigraphic traps. Stratigraphic traps are particularly important in future exploration because of poor anticline trap types in the basin. Some ER stratigraphic traps can be predicted after studying the distribution of systems ER tracts in each sequence as a basic exploration unit. The BPF of TB2.1 which is closed to the source kitchen area could form a large subtle trap. Using the parasequence as a basic unit in reservoir scale will provide a new method to discover new reservoirs. For example, new oil reserves within the predicted stratigraphic trap related to K22, which can be divided into several parasequences in C.A. 16/08, were obtained after drilling. Sequence stratigraphy has become a valid high resolution tool for chronostratigraphic correlation and fine-division and exploration of stratigraphic traps.

  1. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false West Pearl River. 117.511 Section 117.511 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. The draw of...

  2. Rocket Barge on the Pearl River

    NASA Technical Reports Server (NTRS)

    1966-01-01

    During the early 1970's French settlers once cautiously sailed up the beautiful Pearl River in Hancock County looking for a New World home. Later, swashbuckling pirates took refuge in this historic stream in South Mississippi after raiding merchant ships. Today, a different cargo leaves a wake in the blue waters en route to National Aeronautics and Space Administration's Mississippi Test Facility. The huge barge being pushed above contains the free world's largest rocket booster, on its way to the national rocket testing facility for extensive captive firings. Later versions of this huge rocket, first satge of the Apollo/Saturn V, will boost the first Americans to the Moon.

  3. Holocene evolution in weathering and erosion patterns in the Pearl River delta

    NASA Astrophysics Data System (ADS)

    Hu, Dengke; Clift, Peter D.; BöNing, Philipp; Hannigan, Robyn; Hillier, Stephen; Blusztajn, Jerzy; Wan, Shiming; Fuller, Dorian Q.

    2013-07-01

    Sediments in the Pearl River delta have the potential to record the weathering response of this river basin to climate change since 9.5 ka, most notably weakening of the Asian monsoon since the Early Holocene (˜8 ka). Cores from the Pearl River delta show a clear temporal evolution of weathering intensity, as measured by K/Al, K/Rb, and clay mineralogy, that shows deposition of less weathered sediment at a time of weakening monsoon rainfall in the Early-Mid Holocene (6.0-2.5 ka). This may reflect an immediate response to a less humid climate, or more likely reduced reworking of older deposits from river terraces as the monsoon weakened. Human settlement of the Pearl River basin may have had a major impact on landscape and erosion as a result of the establishment of widespread agriculture. After around 2.5 ka weathering intensity sharply increased, despite limited change in the monsoon, but at a time when anthropogenic pollutants (e.g., Cu, Zn, and Pb) increased and when the flora of the basin changed. 87Sr/86Sr covaries with these other proxies but is also partly influenced by the presence of carbonate. The sediments in the modern Pearl River are even more weathered than the youngest material from the delta cores. We infer that the spread of farming into the Pearl River basin around 2.7 ka was followed by a widespread reworking of old, weathered soils after 2.5 ka, and large-scale disruption of the river system that was advanced by 2.0 ka.

  4. 78 FR 44932 - Notice of Intent To Prepare a Draft Environmental Impact Statement for the Pearl River Section...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    .... September 2014. Dated; July 16, 2013. Barbara Petersen, Acting Chief, Programs and Project, Management... Statement for the Pearl River Section 211 Watershed Project for the Pearl River Watershed,...

  5. Water quality survey of Mississippi's Upper Pearl River.

    PubMed

    Tagert, Mary Love M; Massey, Joseph H; Shaw, David R

    2014-05-15

    Surface water samples were collected from May 2002 through May 2003 at seven locations within the Upper Pearl River Basin (UPRB) in east-central Mississippi to assess levels of pesticide impairment in the watershed. Depth-integrated samples were collected at three sites from September 2001 through January 2003 for total dissolved solid (TDS) analysis. Samples were extracted via Solid Phase Extraction (SPE) and analyzed for fifteen pesticides: triclopyr, 2,4-D, tebuthiuron, simazine, atrazine, metribuzin, alachlor, metolachlor, cyanazine, norflurazon, hexazinone, pendimethalin, diuron, fluometuron, and the dichlorodiphenyltrichloroethane (DDT) degradation product p,p'-DDE. Of the analyzed compounds, hexazinone was detected in 94% of the samples, followed by metolachlor (76%), tebuthiuron (48%), and atrazine (47%). Metribuzin was detected in 6% of the samples and was the least detected compound of those analyzed. Sediment concentrations ranged from 20.64 mg/L at Burnside to 42.20mg/L at Carthage, which also had the highest cumulative total sediment concentration at 4,009 mg/L. PMID:24631619

  6. River basin management

    SciTech Connect

    Newsome, D.H.; Edwards, A.M.C.

    1984-01-01

    The quality of water is of paramount importance in the management of water resources - including marine waters. A quantitative knowledge of water quality and the factors governing it is required to formulate and implement strategies requiring an inter-disciplinary approach. The overall purpose of this conference was to bring together the latest work on water quality aspects of river basin management. These proceedings are structured on the basis of five themes: problems in international river basins; the contribution of river systems to estuarial and marine pollution; the setting of standards; monitoring; and practical water quality management including use of mathematical models. They are followed by papers from the workshop on advances in the application of mathematical modelling to water quality management, which represent some of the current thinking on the problems and concepts of river basin management.

  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. Gas hydrate distribution identified from wireline logging data and seismic data in the Pearl River Mouth Basin,northern slope of South China Sea

    NASA Astrophysics Data System (ADS)

    Wang, X.; Wu, S.; Yang, S.

    2012-12-01

    Wireline logging data acquired during China's first gas hydrate drilling expedition (GMGS-1) in April-June of 2007 and seismic data indicate the occurrences of gas hydrate above the base of gas hydrate stability (BGHS). Bottom simulating reflectors (BSRs) are widespread in the drilling zone, predominantly occurring beneath the ridges of migrating submarine canyons. Higher P-wave velocities and higher resistivity above BGHS at sites SH3, SH2 and SH7 indicate the presence of gas hydrate in the thickness range from 10 to 25 meters below seafloor. However, the measured compressional (P-wave) velocities at site SH3 show there are three abnormal P-wave velocities zones above the BGHS, which are lower than those of water-saturated sediments, indicating the presence of free gas in the pore space. The P-wave velocities drop as low as 1.0 m/s at the depth of 125 m. While the recovered core at 100 bars degassed show that methane was under unsaturated. Below the BSR, seismic data show enhanced reflections and the P-impedances have lower values, which inferred these reflections to be caused by free gas. To determine whether the low well-log P-wave velocity is caused by in-situ gas, synthetic seismograms were generated using the measured well-log P-wave velocity and calculated assuming water-saturated in the pore space. Comparing the surface seismic data with synthetic seismograms suggests that low P-wave velocities are likely caused by migrating gas due to borehole drilling. Three dimensional (3D) multi-channel seismic (MCS) data, inverted P-wave velocity, and RMS amplitude are used to study the detailed distribution and occurrences of the BSR and associated with the migration of gas in this basin. Three types of BSR and amplitude anomalies zones are identified from 3D seismic data. Gas hydrate in this basin are linked to and associated with gas accumulation below gas hydrate stability zone, which has a closerelationship with focused fluid flow features such as gas chimneys

  9. 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

  10. Floodplain influence on carbon speciation and fluxes from the lower Pearl River, Mississippi

    NASA Astrophysics Data System (ADS)

    Cai, Yihua; Shim, Moo-Joon; Guo, Laodong; Shiller, Alan

    2016-08-01

    To investigate the floodplain influence on carbon speciation and export to the northern Gulf of Mexico, water samples were collected monthly from two sites in the East Pearl River (EPR) basin during 2006-2008. Additionally, four spatial surveys in the river basin between those two sites were also conducted. Compared with the upstream sampling site at Bogalusa, MS, dissolved inorganic carbon (DIC) and particulate organic carbon (POC) concentrations were 36% and 55% lower, respectively, and dissolved organic carbon (DOC) concentration was 49% higher at the downstream Stennis Space Center (SSC) site. In addition, the bulk DOC pool at SSC had a higher colloidal fraction than at Bogalusa (75% vs. 68%). Detailed spatial surveys revealed the differences between the upstream and downstream stations resulted both from input from Hobolochitto Creek, a tributary of the EPR, and from influence of the swamp-rich floodplain. The contributions from Hobolochitto Creek to the carbon pool in the EPR basin were lowest during a high flow event and reached a maximum during the dry season. Meanwhile, the floodplain in the EPR basin acted as a significant sink for DOC, POC and particulate nitrogen during summer and for suspended sediment during a high flow event. However, the floodplain was converted into a source of suspended sediment, DOC, and POC to the EPR during winter, revealing a dynamic nature and seasonality in the floodplain influence. Consistent with its dominant forest coverage, abundant wetlands along the river corridor, and mild anthropogenic disturbance, the Pearl River basin above Bogalusa generally had higher yields of DOC and POC (1903 and 1386 kg-C km-2 yr-1, respectively), but a lower yield of DIC (2126 kg-C km-2 yr-1) compared to other North American rivers. An estimation based on a mass balance approach suggests the interactions between floodplain and the main river stem could reduce the annual DIC and POC export fluxes from downstream of the EPR by 24% and 40

  11. Trinity river basin, Texas

    USGS Publications Warehouse

    Ulery, Randy L.; Van Metre, Peter C.; Crossfield, Allison S.

    1993-01-01

    In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. Physical characteristics described include climate, geology, soils, vegetation, physiography, and hydrology. Cultural characteristics discussed include population distribution, land use and land cover, agricultural practices, water use, an reservoir operations. Major water-quality categories are identified and some of the implications of the environmental factors for water quality are presented.

  12. The continent-ocean transition of the Pearl River margin

    NASA Astrophysics Data System (ADS)

    Cameselle, A. L.; Ranero, C. R.; Franke, D.; Barckhausen, U.

    2013-12-01

    Rifted continental margins form by lithospheric extension and break-up. The continent to ocean transition (COT) architecture depends on the interplay between tectonic and magmatic processes, and thus, to study the COT variability of different systems is key to understand rifting. We use MCS data and magnetic lineations across the Pearl River margin (PRM) of South China Sea to investigate a previously poorly defined COT. The structure of the PRM presents different amounts of extension allowing the study of conjugate pairs of continental margins and their COT in a relative small region. We reprocessed about 2250 km of MCS data along 4 regional, crustal-scale lines and found that 3 of them possibly display the COT. The time-migrated seismic sections show differences in internal reflectivity, faulting style, fault-block geometry, the seismic character of the top of the basement, in the geometry of sediment deposits, and Moho reflections, that we interpret to represent clear continental and oceanic domains. The continental domain is characterized by arrays of normal faults and associated tilted blocks overlaid by syn-rift sedimentary units. The Moho is imaged as sub-horizontal reflections that define a fairly continuous boundary typically at 8-10 s TWT. Estimation of the thickness of the continental crust using 6 km/s average velocity indicates a ~22 km-thick continental crust under the uppermost slope passing abruptly to ~9-6 km under the lower slope. Comparatively the oceanic crust has a highly reflective top of basement, little-faulting, not discernible syn-tectonic strata, and fairly constant thickness (4-8 km) defined by usually clear Moho reflections. The COT occurs across a ~5-10 km narrow zone. Rifting resulted in asymmetric conjugate margins. The PRM shows arrays of tilted fault blocks covered by abundant syn-rift sediment, whereas the conjugate Macclesfield Bank margin displays abrupt thinning and little faulting. Seismic profiles also show a change in the

  13. Water chemistry of the Zhujiang (Pearl River): Natural processes and anthropogenic influences

    NASA Astrophysics Data System (ADS)

    Zhang, Shu-Rong; Lu, Xi Xi; Higgitt, David Laurence; Chen, Chen-Tung Arthur; Sun, Hui-Guo; Han, Jing-Tai

    2007-03-01

    The temporal and spatial variations of major ions in the Zhujiang (Pearl River) were analyzed using long-term water chemistry data of major dissolved ions (Ca2+, Mg2+, the sum of Na+ and K+, HCO3-, SO42-, Cl-) and dissolved silica (SiO2) from 75 hydrological stations (1958-2002). The total dissolved solids (TDS) within the Zhujiang basin varies from 34.0 mg/l to 416.1 mg/l generally decreasing from upstream to downstream along the main stem of the Zhujiang. Rock weathering is the dominant controlling factor for the water chemistry of the Zhujiang, and more specifically, on average, 68% (22-92%) of total dissolved load comes from carbonate weathering, 22% (2-68%) from silicate weathering, and 10% (3-24%) from evaporite weathering, respectively. The flux calculations indicate that in total about 41.8 × 106 tonnes/year of TDS are transported out of the Zhujiang (excluding the Delta Region), averaged for the period 1958-2002. Changes in water chemistry can be observed from long-term trend analysis, notably for SO42- and Cl-, as a result of anthropogenic influences, such as acid deposition, domestic and industrial wastewater discharge, and basin water resource development. An intense reforestation policy coupled with rapid reservoir development in the Zhujiang Basin would trigger more significant anthropogenic impacts on water chemistry in the future.

  14. 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. PMID:26780062

  15. 77 FR 47331 - Regulated Navigation Area-New Haven Harbor, Quinnipiac River, Mill River, New Haven, CT; Pearl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms COTP Captain of the Port DHS Department of Homeland Security FR... Federal Register (73 FR 3316). 4. Public Meeting We do not now plan to hold a public meeting. But you may... River, Mill River, New Haven, CT; Pearl Harbor Memorial Bridge (Interstate 95) Construction...

  16. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... Bureau of Reclamation Yakima River Basin Conservation Advisory Group; Yakima River Basin Water... on the structure, implementation, and oversight of the Yakima River Basin Water Conservation Program... of the Water Conservation Program, including the applicable water conservation guidelines of...

  17. Intrusion of the Pearl River plume into the main channel of the Taiwan Strait in summer

    NASA Astrophysics Data System (ADS)

    Bai, Yan; Huang, Ting-Hsuan; He, Xianqiang; Wang, Shu-Lun; Hsin, Yi-Chia; Wu, Chau-Ron; Zhai, Weidong; Lui, Hon-Kit; Chen, Chen-Tung Arthur

    2015-01-01

    The Penghu Channel is the main channel connecting the East and South China Seas, two of the largest marginal seas in the world. Located in the southeast of Taiwan Strait, the Penghu Channel is usually covered by the high salinity water from the South China Sea and the Kuroshio. However, we observed abnormal low-salinity water in the Penghu Channel during a cruise through the southern Taiwan Strait and northern South China Sea in August 2008. We argue that the normalized alkalinity is a good indicator for the identification of a river plume as it is not affected by rainwater. Using satellite-derived water transparency and chlorophyll images and field-measured alkalinity, the source of this low salinity water was found to be the intrusion of the Pearl River plume. A significant phytoplankton bloom across the entire Taiwan Strait occurred with the intrusion event. The intrusion was not a unique event, as we also found a strong jet-shaped Pearl River plume intruding into the Penghu Channel in the summer of 2009 from cloud-free satellite-derived images. Time series satellite data reveal that the Pearl River plume intrudes into the Penghu Channel in the summer of most years. Multiple data analysis and modeling simulation indicate that a large river discharge and strong southwesterly winds on the shelf may be responsible for the significant intrusion of the Pearl River plume into the Penghu Channel in summer. As the Pearl River plume has a high nutrient and dissolved inorganic carbon content, combined with the strong northward flows through the Penghu Channel, such intrusions may contribute to the nutrient dynamics and carbon budget of the East and northern South China Seas.

  18. EAARL Coastal Topography-Pearl River Delta 2008: First Surface

    USGS Publications Warehouse

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Miner, Michael D.; Michael, D.; Yates, Xan; Bonisteel, Jamie M.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived first surface (FS) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the University of New Orleans (UNO), Pontchartrain Institute for Environmental Sciences (PIES), New Orleans, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Pearl River Delta in Louisiana and Mississippi, acquired March 9-11, 2008. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the

  19. EAARL Coastal Topography-Pearl River Delta 2008: Bare Earth

    USGS Publications Warehouse

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Miner, Michael D.; Yates, Xan; Bonisteel, Jamie M.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the University of New Orleans (UNO), Pontchartrain Institute for Environmental Sciences (PIES), New Orleans, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Pearl River Delta in Louisiana and Mississippi, acquired March 9-11, 2008. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the

  20. 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...

  1. Hurricane Katrina impact on water quality in the East Pearl River, Mississippi

    NASA Astrophysics Data System (ADS)

    Shiller, Alan M.; Shim, Moo-Joon; Guo, Laodong; Bianchi, Thomas S.; Smith, Richard W.; Duan, Shuiwang

    2012-01-01

    SummaryHurricanes and other intense storms have previously been reported to cause short-term changes in surface water quality. We examined the water quality of the East Pearl River in southern Mississippi both before and after Hurricane Katrina caused extensive damage to the watershed in 2005. Our post-storm sampling began two months after the hurricane, and thus we missed any immediate short-term consequences. However, sampling over the following two years allowed us to examine whether damage to the watershed resulted in significant longer-term effects on water quality. Interpretation of the time series data is complicated by the natural seasonal and climatic variability of the system. Thus, we utilized chemical property-property plots as well as semi-empirical relationships to compare pre- and post-storm water quality. Our analysis suggests that hurricane-induced vegetative destruction within this river basin has not substantially changed the concentrations of DOC, POC, SPM, pH, or dissolved Fe. However, lignin-phenol analysis of colloidal organic matter did show some significant changes in carbon-normalized concentration as well as in some degradation and source parameters. Nonetheless, even these changes were small and likely temporary. This lack of change may be partly due to the slow degradation of woody materials that occurs only over a period of a few years, even in the sub-tropical climate of this region. Also, transport of DOC material from the land, through the soils, and into the river is not always instantaneous because DOC may stay in soils for a long time. Our work can be examined in the context of other research focused on hurricane effects on different time scales. For instance, shorter term hurricane influences, such as immediate flooding, can cause concurrent, short-lived water quality changes. Likewise, if increased hurricane activity (as might result from climate change) results in permanent landscape or ecosystem changes, then significant long

  2. Long-term NO2 monitoring by satellite in the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Li, Long; Shi, Runhe; Liu, Pudong; Zhang, Jie

    2013-09-01

    Recently, the air quality has been continuing to deteriorate and threaten public health in the Pearl River Delta. China, the host country for the 2010 Asian Games, faced the great challenge of air quality issues, particularly in the Pearl River Delta, where the Asian Games were held. The major aim of this study is to reveal the spatial and temporal characteristics of NO2 in the Pearl River Delta during October 2004 to December 2010. The long-term characteristics and variations of the NO2 column concentration before and during the 2010 Asian Games were analyzed by using the NO2 product OMNO2e from the Ozone Monitoring Instrument (OMI). Results show that the annual average of the NO2 column concentration has a significant downward trend from 2005 to 2010 in the Pearl River Delta: the total column concentration of NO2 (TotNO2) in the atmosphere decreased from 9.207×1015 molec/cm2 to 8.173×1015 molec/cm2, with an average annual rate of -2.247%; the tropospheric column concentration of NO2 (TropNO2)decreased from 6.685×1015 molec/cm2 to 5.646×1015 molec/cm2, with an average annual rate of -3.109%. The ratio TropNO2/TotNO2 indicating the amount of NO2 exhausted by human activities also decreased from 0.726 in 2005 to 0.691 in 2010. During the 2010 Asian Games, the weekly average of the TropNO2 in Pearl River Delta was maintained at a low level. The NO2 average distribution in the Pearl River Delta is characterized by the maximum in the geometric center, outwardly smaller, and the shrinking areas with high TropNO2 concentration from 2005 to 2010. Foshan, Jiangmen and Kwangchowan were severely polluted cities during the Games. However, the air quality of the Pearl River Delta was improved compared to its historical periods due to governmental preventive/control measures during the 2010 Asian Games.

  3. 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

  4. Ratio of nitrogen to phosphorus in the Pearl River and effects on the estuarine coastal waters: Nutrient management strategy in Hong Kong

    NASA Astrophysics Data System (ADS)

    Yin, Kedong; Harrison, Paul J.; Broom, Malcolm; Chung, C. H.

    The Pearl River is the second largest river in China, and has a 454,000 km 2 drainage basin. Excess nutrients can result in algal blooms, or even harmful algal blooms and subsequent dissolved oxygen (DO) consumption can lead to hypoxia. However, not all nutrients are equal; only one nutrient relative to other nutrients is the most limiting for algal biomass production and the other nutrients that are in excess cannot be used to produce a further increase in an algal bloom. Therefore, the strategy of nutrient pollution control is to remove the most limiting nutrient from the sewage effluent to minimize eutrophication impacts on the receiving waters. This, in turn, determines the type and level of sewage treatment. In the Pearl River, nitrogen (N) is very high and phosphorus (P) is relatively low, leading to a very high N:P ratio. The Pearl River flows into coastal waters in the South China Sea and heavily influences Hong Kong waters located to the east of the Pearl River estuary. When the Hong Kong government planned to upgrade the domestic sewage facility to biological treatment, this triggered the scientific question of which nutrient, N or P is the most limiting nutrient and the answer to this question became critical in making the management decision on the treatment facilities for removal of N or P, which bears a huge financial implication. In the past, because N is high in southern waters, it was thought that any addition of N would exceed the environmental assimilation capacity and result in algal blooms. Therefore, N has been typically considered for removal from sewage effluent. However, evidence revealed that P was the most limiting nutrient in the southern waters of Hong Kong and it actually limits phytoplankton biomass accumulation and potentially limits bacterial DO consumption. Hence, the removal of P has been suggested to receive priority over N removal, if there is a need for the future elevation of treatment levels. However, as this conclusion is

  5. Long-term process-based morphodynamic modeling of the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Wei, Xing; Wu, Chaoyu

    2014-12-01

    The Pearl River Delta (PRD) is one of the most complex large-scale estuarine systems in China. A long-term morphodynamic model is developed to simulate the evolution of the PRD and its estuarine system. The driving forces and control factors considered in the model include river discharge, representative tides, and sediment supply from the Pearl River system; sediment compaction; neotectonic movement; and sea-level variation. Core data with 14C dating at 40 locations are used to validate the model output with satisfactory results. New findings on the mid-Holocene evolution of the PRD show that the delta's chronological and spatial evolution pattern is different from those found in previous studies in several respects. The model confirms that complex morphologies, e.g., rocky islands in shallow estuarine bays, are some of the most important factors affecting the long-term evolution of the PRD.

  6. Sectorial Water Use Trends in the Urbanizing Pearl River Delta, China

    PubMed Central

    Yao, Mingtian; Werners, Saskia E.; Hutjes, Ronald W. A.; Kabat, Pavel; Huang, Heqing

    2015-01-01

    Assessing and managing water use is crucial for supporting sustainable river basin management and regional development. The first consistent and comprehensive assessment of sectorial water use in the Pearl River Delta (PRD) is presented by analysing homogenized annual water use data from 2000 to 2010 in relation to socio economic statistics for the same period. An abstraction of water use, using the concept of water use intensity, and based on equations inspired by those used in global water resource models, is developed to explore the driving forces underlying water use changes in domestic, industrial and agricultural sectors. We do this at both the level of the region as a whole, as well as for the nine cities that constitute the PRD separately. We find that, despite strong population and economic growth, the PRD managed to stabilize its absolute water use by significant improvements in industrial water use intensities, and early stabilisation of domestic water use intensities. Results reveal large internal differentiation of sectorial water use among the cities in this region, with industrial water use intensity varying from -80 to +95% and domestic water use intensity by +/- 30% compared to the PRD average. In general, per capita water use is highest in the cities that industrialised first. Yet, all cities except Guangzhou are expected to approach a saturation value of per capita water use much below what is suggested in recent global studies. Therefore, existing global assessments probably have overestimated future domestic water use in developing countries. Although scarce and uncertain input data and model limitations lead to a high level of uncertainty, the presented conceptualization of water use is useful in exploring the underlying driving forces of water use trends. PMID:25714731

  7. Sectorial water use trends in the urbanizing Pearl River Delta, China.

    PubMed

    Yao, Mingtian; Werners, Saskia E; Hutjes, Ronald W A; Kabat, Pavel; Huang, Heqing

    2015-01-01

    Assessing and managing water use is crucial for supporting sustainable river basin management and regional development. The first consistent and comprehensive assessment of sectorial water use in the Pearl River Delta (PRD) is presented by analysing homogenized annual water use data from 2000 to 2010 in relation to socio economic statistics for the same period. An abstraction of water use, using the concept of water use intensity, and based on equations inspired by those used in global water resource models, is developed to explore the driving forces underlying water use changes in domestic, industrial and agricultural sectors. We do this at both the level of the region as a whole, as well as for the nine cities that constitute the PRD separately. We find that, despite strong population and economic growth, the PRD managed to stabilize its absolute water use by significant improvements in industrial water use intensities, and early stabilisation of domestic water use intensities. Results reveal large internal differentiation of sectorial water use among the cities in this region, with industrial water use intensity varying from -80 to +95% and domestic water use intensity by +/- 30% compared to the PRD average. In general, per capita water use is highest in the cities that industrialised first. Yet, all cities except Guangzhou are expected to approach a saturation value of per capita water use much below what is suggested in recent global studies. Therefore, existing global assessments probably have overestimated future domestic water use in developing countries. Although scarce and uncertain input data and model limitations lead to a high level of uncertainty, the presented conceptualization of water use is useful in exploring the underlying driving forces of water use trends. PMID:25714731

  8. 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.

  9. Sediment trapping by haloclines of a river plume in the Pearl River Estuary

    NASA Astrophysics Data System (ADS)

    Ren, Jie; Wu, Jiaxue

    2014-07-01

    Sediment trapping by the halocline of a river plume was investigated over a spring-neap tidal cycle in the 2010 dry season in the Pearl River Estuary. Benthic tripod observations and concurrent shipboard measurements were conducted to examine mean and turbulent flows, and sediment distributions. The field observations showed that suspended particles are apparently concentrated on the halocline of the river plume, forming a patchy high-concentration suspension with larger floc sizes. This sediment trapping occurred only on the neap tide when the estuary was highly stratified. An estimation of the gradient Richardson number indicates that stratification suppression is dominant below the halocline, whereas shear-induced instability occurs above the halocline. The turbulent kinetic energy balance demonstrates that the buoyancy flux dominates over viscous dissipation in turbulence destruction. Therefore, the trapping of suspended sediment with large floc sizes on the halocline is induced by both salinity stratification and buoyancy-induced instability. This finding can explain the role of salinity stratification in the mechanism for estuarine turbidity maxima and long-distance transportation of suspended sediment.

  10. Impacts of flow regulation on freshwater pearl mussel (Margaritifera margaritifera) habitat in a Scottish montane river.

    PubMed

    Addy, Stephen; Cooksley, Susan L; Sime, Iain

    2012-08-15

    The River Moriston in NW Scotland is a cobble-gravel bedded river that has been dammed and regulated for hydroelectric power (HEP) since 1956. The river supports a functional population of the critically endangered freshwater pearl mussel (Margaritifera margaritifera) in the lower part. In contrast the population in the upper reach is sparse and shows no signs of juvenile recruitment, leading to speculation that hydrological and geomorphic changes associated with HEP have degraded the habitat they depend on. A combination of historical analysis, field mapping and geomorphic survey of channel and active bar sites was used to assess habitat changes and current quality. During the post-dam period, the naturally stability of much of the channel has increased, active bars have been stabilised through vegetation colonisation, riparian tree cover has increased and the active channel width has significantly reduced locally (>50%); adjustments that are indicative of a reduction in the incidence of competent flows caused by flow regulation. However area and stability of habitat for freshwater pearl mussels have not been reduced greatly. The channel sites examined are characterised by mixed cobble-gravel substrates (D(50) range=46-188 mm), predicted to be highly stable, that provide suitable habitat for adult freshwater pearl mussels. However a degree of bed compaction at one site was observed that could be limiting the recruitment of juvenile mussels. It is hypothesised that the sparse, non-functional status of the freshwater pearl mussel population reflects significant historical pearl fishing and the limitation of recovery due to HEP related pressures of fish migration obstruction and bed compaction. The implications of these factors for conservation of the species are discussed. PMID:22750177

  11. Ecological River Basin Management.

    ERIC Educational Resources Information Center

    Smith, Anthony Wayne

    Addressing the Seventh American Water Resources Conference, Washington, D. C., October, 1971, Anthony Wayne Smith, President, National Parks and Conservation Association, presents an expose on how rivers should be managed by methods which restores and preserve the natural life balances of the localities and regions through which they flow. The…

  12. Variability in the bulk composition and abundance of dissolved organic matter in the lower Mississippi and Pearl rivers

    NASA Astrophysics Data System (ADS)

    Duan, Shuiwang; Bianchi, Thomas S.; Shiller, Alan M.; Dria, Karl; Hatcher, Patrick G.; Carman, Kevin R.

    2007-06-01

    In this study, we examined the temporal and spatial variability of dissolved organic matter (DOM) abundance and composition in the lower Mississippi and Pearl rivers and effects of human and natural influences. In particular, we looked at bulk C/N ratio, stable isotopes (δ15N and δ13C) and 13C nuclear magnetic resonance (NMR) spectrometry of high molecular weight (HMW; 0.2 μm to 1 kDa) DOM. Monthly water samples were collected at one station in each river from August 2001 to 2003. Surveys of spatial variability of total dissolved organic carbon (DOC) and nitrogen (DON) were also conducted in June 2003, from 390 km downstream in the Mississippi River and from Jackson to Stennis Space Center in the Pearl River. Higher DOC (336-1170 μM), C/N ratio,% aromaticity, and more depleted δ15N (0.76-2.1‰) were observed in the Pearl than in the lower Mississippi River (223-380 μM, 4.7-11.5‰, respectively). DOC, C/N ratio, δ13C, δ15N, and % aromaticity of Pearl River HMW DOM were correlated with water discharge, which indicated a coupling between local soil inputs and regional precipitation events. Conversely, seasonal variability in the lower Mississippi River was more controlled by spatial variability of a larger integrative signal from the watershed as well as in situ DOM processing. Spatially, very little change occurred in total DOC in the downstream survey of the lower Mississippi River, compared to a decrease of 24% in the Pearl River. Differences in DOM between these two rivers were reflective of the Mississippi River having more extensive river processing of terrestrial DOM, more phytoplankton inputs, and greater anthropogenic perturbation than the Pearl River.

  13. Graptemys pearlensis Ennen, Lovich, Kreiser, Selman, and Qualls 2010 – Pearl River Map Turtle

    USGS Publications Warehouse

    Ennen, Joshua R.; Lovich, Jeffrey E.; Jones, Robert L.

    2016-01-01

    The Pearl River Map Turtle, Graptemys pearlensis (Family Emydidae), is a moderate-sized aquatic turtle endemic to the Pearl River drainage of Louisiana and Mississippi. This taxon has long been a cryptic species, as it was considered part of G. pulchra before 1992 and part of G. gibbonsi until 2010. Graptemys pearlensis exhibits sexual dimorphism, with adult females being considerably larger (carapace length to 295 mm) than adult males (CL to 121 mm). In the 1960s and 1970s, the species was commonly found in higher abundance than the sympatric G. oculifera, a federally listed species. However, due to habitat degradation and the precipitous decline of native mollusks, the species is now found in lower numbers than G. oculifera throughout much of its range. The current IUCN Red List status is Endangered; however, very little is known about the natural history and ecology of the species, which will make conservation efforts challenging.

  14. Benthic foraminiferal assemblages and trace metals reveal the environment outside the Pearl River Estuary.

    PubMed

    Li, Tao; Xiang, Rong; Li, Tuanjie

    2013-10-15

    We investigated the distribution patterns of the benthic foraminiferal assemblages outside the Pearl River Estuary in relation to trace metals, organic carbon and sedimentary particle fractions. The study area is unpolluted to moderately polluted by Cr, Cu, Pb and Zn and is completely polluted by Ni. The highest levels are found in the western coastal zone. Spatial distributions of the measured elements are strongly related to the behavior of the sedimentary clay fraction. The analyses of species abundance and community diversity as well as subsequent canonical correspondence analysis were used to reveal the relationship between foraminifera data and environmental parameters. Four sampling site groups established by factor analysis were distributed from the coastal area to the inner shelf. Their distribution patterns have a strong correlation with Cu, Pb and Ba. This research shows that benthic foraminifera can be used as bioindicators of trace metal pollutants outside the Pearl River Estuary. PMID:23972678

  15. The surface sediment distribution and sedimentary environment of the Pearl River Submarine Canyon

    NASA Astrophysics Data System (ADS)

    Han, X.; Chu, F.; Li, J.; Xu, D.; Zhang, W.

    2012-12-01

    The grain size composition, particle size parameters, clay mineral, and detrital mineral of surface sediment of this The Pearl River Submarine Canyon (the PRSC, for short) area have been measured and analyzed, which were took sampling in 2005 and 2006 in the northern South China Sea. The results show that the isolines distribution features of these parameters have very good corresponding relation with the geomorphology of the PRSC. On the continental-shelf slope break of the PRSC head (123m-1500m water depth), the close interval isolines of the surface sediment particle size percentage content and size parameters nearly parallel with the water depth isolines. The data of sand percentage content and mean grain size, sorting coefficient and skewness decreases with the increase of water depth. The other way around, the silt and clay percentage content and kurtosis value increase with deeper water. These show that in the canyon head sediment distribution was controlled by the material source (mainly comes from the Pearl River), slope and the northern South China Sea offshore current. In the main PRSC area, the surface sediment grain size composition content and grain size parameter numerical isolines have become a isoline platform which has the similar shape with the main PRSC and extended to the northeast and southwest deep sea basin. This means that the sedimentary environment of main canyon is apparently different with the head environment, that is affected by the high-temperature and high-salt the South China Sea Branch of by the Kuroshio along the 3500 m water depth isoline and alone the canyon to bending. The 25% percentage content isoline of the calcium biological and 45% percentage content isoline of the light mineral show a broadband distribution along the head and upside of the PRSC, and reduces in the entrance with the water depth isolines, apparently influenced by the South China Sea Branch of the Kuroshio. A high value area of the silt, clay mineral, light

  16. 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.

  17. [Ecological risk assessment of organophosphorus pesticides in aquatic ecosystems of Pearl River Estuary].

    PubMed

    Guo, Qiang; Tian, Hui; Mao, Xiao-Xuan; Huang, Tao; Gao, Hong; Ma, Jian-Min; Wu, Jun-Nian

    2014-03-01

    The risk quotient method and a probabilistic risk assessment method were applied for assessing aquatic ecological risk of nine organophosphorus pesticides, including thimet, dichlorovos, disulfoton, dimethoate, dimethyl parathion, chlorpyrifos, ethoprophos, sumithion and malathion on eight aquatic organisms in the Pearl River Estuary. Results using the risk quotient method revealed that the risk level of opossum shrimp was the highest among eight aquatic organisms of the Pearl River Estuary. The risk of water flea and midge was in medium level, followed by the rest six aquatic organisms, including diatom, oyster, carp, catfish and eel, which were in the low risk by the examined organophosphorus pesticides. It was found that thimet made the largest contribution to total aquatic ecological risk among nine organophosphorus pesticides to every organism. The results from probabilistic risk assessment showed that the total ecological risk in high water period was higher than that in low water period determined by the HC5 under the 95% confidence level. The largest contribution of thimet to total aquatic ecological risk subject to the HC5 in 50% confidence level was regarded as the toxic reference value. The probabilistic risk of a single contaminant showed that thimet and disulfoton were harmful to exceeded 10% organisms in the estuarine. The probabilistic risk of nine pesticides mixture in high water period was also higher than that in low water period, and both risks were greater than 5% which exceeded safety threshold for 95% organisms in the Pearl River Estuary. PMID:24881393

  18. 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.

  19. Trace organic contamination in biota collected from the Pearl River Estuary, China: a preliminary risk assessment.

    PubMed

    Wei, S; Lau, R K F; Fung, C N; Zheng, G J; Lam, J C W; Connell, D W; Fang, Z; Richardson, B J; Lam, P K S

    2006-12-01

    The marine ecosystem of the Pearl River Delta, located on the southern coast of China, has been heavily exploited following the rapid economic growth that has occurred since the 1980s. This investigation aimed to elucidate trace organic contamination in marine biota inhabiting the Pearl River Delta area. Biota samples, including green-lipped mussels (Perna viridis), oysters (Crassostrea rivularis) and shrimp (Penaeus orientalis) were sampled from 16 stations fringing the Estuary. Elevated concentrations (on a dry weight basis) of polycyclic aromatic hydrocarbons (27.8-1041.0 ng/g), petroleum hydrocarbons (1.7-2345.4 microg/g), polychlorinated biphenyls (2.1-108.8 ng/g), DDTs (1.9-79.0 ng/g), and hexachlorocyclohexanes (n.d.-38.4 ng/g) were recorded. A human health risk assessment was conducted to estimate the risk to local residents associated with the consumption of biota collected from the Pearl River Estuary. The results indicated that PCBs were at levels that may cause deleterious health effects in populations that consume large amounts of seafood. However, it would be instructive to establish health criteria for trace organic contaminants that are specific to the local populations, in order to derive a more accurate and relevant health risk assessment. PMID:16908034

  20. Enhanced abundance and diversity of ammonia-oxidizing Archaea in the Pearl River estuary

    NASA Astrophysics Data System (ADS)

    Xie, W.; Zhang, C. L.; Wang, P.; Zhou, X.; Guo, W.

    2014-12-01

    Thaumarchaeota are recently recognized as an important group of Archaea that can perform aerobic oxidation of ammonia in a wide range of environments. The goal of this study was to evaluate changes in abundance and diversity of planktonic ammonia-oxidizing Archaea (e.g., Thaumarchaeota) along a salinity gradient from the lower Pearl River to the northern South China Sea. Quantitative PCR and sequencing of total archaeal 16S rRNA gene and the archaeal amoA gene were performed on suspended particulate organic matter collected in different seasons from the freshwater to the ocean water. Total amoA gene copies and relative abundance of Thaumarchaeota all peaked in the estuary where salinity ranged between 4.5‰ and 26.7‰. The diversity of archaeal amoA gene was also highest in the estuary. Seasonality and SiO32- appear to be two major factors affecting the distribution of subclusters of archaeal amoA genes. For example, Nitrosopumilus subcluster 7.1 was most abundant in winter in fresh water, whereas Nitrososphaera were more abundant in summer. Samples collected from the area around Wanshan Island, which is located at the outermost part of the Pearl River estuary, had high abundance of unclassified archaeal amoA genes, suggesting some new groups of Thaumarchaeota might inhabit this water body. Overall, the high abundance and diversity of Thaumarchaeota in the Pearl River estuary may indicate enhanced role of AOA in nitrogen cycle in this dynamic ecosystem.

  1. Endocrine-disrupting chemicals in the Pearl River Delta and coastal environment: sources, transfer, and implications.

    PubMed

    Xu, Weihai; Yan, Wen; Huang, Weixia; Miao, Li; Zhong, Lifeng

    2014-12-01

    A study was conducted to investigate the occurrence and behavior of six endocrine-disrupting chemicals (EDCs) in sewage, river water, and seawater from the Pearl River Delta (PRD). The six EDCs under study were 4-nonylphenol (NP), bisphenol A (BPA), 17α-ethynylestradiol (EE2), estrone (E2), 17β-estradiol (E2), and estriol (E3). These EDCs, predominated by BPA, were found in high levels in the influents and the effluents of sewage treatment plants in the area. The relatively high concentrations (0.23-625 ng/L) of the EDCs detected in the receiving river water suggested that the untreated sewage discharge was a major contributor. The EDCs detected in eight outlets of the Pear River and the Pear River Estuary were in the ranges of 1.2-234 and 0.2-178 ng/L, respectively. The estrogen equivalents in the aquatic environments under study ranged from 0.08 to 4.5 ng/L, with E1 and EE2 being the two predominant contributors. As the fluxes of the EDCs from the PRD region to the nearby ocean are over 500 tons each year, the results of this study point to the potential that Pearl River is a significant source of the EDCs to the local environment there. PMID:24817613

  2. Dissolved and Particulate Amino Acids in the Lower Mississippi and Pearl Rivers (USA)

    NASA Astrophysics Data System (ADS)

    Duan, S.; Bianchi, T. S.

    2006-12-01

    Seasonal changes (monthly samples) in abundance and composition of dissolved and particulate amino acids were observed at one station in the lower Mississippi and Pearl Rivers (MS, USA) from September 2001 to August 2003. Spatial variability was also observed during a 4 day transmit from river-mile 225 to river mouth (Head of Passes, LA) in the Mississippi River, and a two-day downstream sampling from Jackson (MS) to Stennis Space Center (MS). Temporal data in the lower Mississippi River showed significantly lower concentrations of dissolved combined amino acids (DCAA, 0.45-1.4 μ M) and dissolved amino acids in high molecular weight fraction (HMW DAA, 0.13-0.27 μ M) than in the Pearl River (DCAA, 0.91-2.8 μ M; HMW DAA, 0.25-0.95 μ M). DCAA and HMW DAA in both rivers were generally higher during high-flow periods. DFAA was significantly lower than DCAA in both rivers (0.05-0.08 μ M), and displayed minimal seasonal variability. Total particulate amino acids (PAA) in both rivers were in the same range (0.7-1.4 μ M). A C- normalized yield of PAA (PAA-C/POC) was negatively correlated with suspended particulate matter and positively with chl-a in both rivers. No significant difference in PAA composition was observed in the two rivers. However, PAA in both rivers was relatively enriched in arginine, alanine, methionine and leucine, and depleted in aspartic acid, serine, and non-protein amino acids, compared to DCAA. While DCAA spatial variability in the lower Mississippi River was minimal, decreases in PAA (from 1.06 to 0.43 μ M) were consistent with particulate organic carbon (POC) and particulate nitrogen (PN). Frequent variations in the PAA-C/POC ratio were inversely correlated with suspended particulate matter and PAA (R = -0.7, n = 48), suggesting short- scale sedimentation and resuspension events. A gradual increase in % non-protein AA along with a loss of phytoplankton biomass along the river, suggested was indicative of bacterial utilization of labile

  3. Estimating suspended sediment loads in the Pearl River Delta region using sediment rating curves

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Wei, Xiaoyan; Jinhai, Zheng; Yuliang, Zhu; Zhang, Yanjing

    2012-04-01

    In this study, sediment rating curves are employed to study the variations in relationships between water discharge and suspended sediment concentration based on the recent 50 years of monthly data set in the three major rivers of the Pearl River Delta. Results show that sediment rating parameters vary with time. The lowest rating coefficient, ln(a), and the highest rating exponent, b, mostly occur in the 1980s, indicating that sediment transport reached its peak in this decade at the same level as water discharge. This upward shift of sediment load is probably caused by exacerbated karst rocky desertification in the upper reaches of the Pearl River. However, since the beginning of the 1990s sediment loads from the Pearl River to its estuary began to show a dramatically decreasing trend, which is attributed mainly to deposition in the reservoirs, leading to an increase of ln(a) and a decrease of b. Furthermore, the sediment rating curve in 1957 to1970 is applied to estimate potential sediment load (1971 to 2006) in the absence of human influences. It is also estimated quantitatively by the sediment rating curves that in the 1980s, the annual sediment load decreased by 7.59×106 t/yr because of natural factors, while sediment increase induced by human activities was 20.07×106 t/yr, which resulted in an actual increased sediment load of 12.47×106 t/yr compared with the reference level in 1957 to 1970. In the last two decades, the difference between measured and estimated sediment loads became considerable, and the annual deficit sharply increased to 26.80×106 t/yr in the 1990s, and 50.46×106 t/yr in the 2000s, indicating that human activities, mainly referring to dam and reservoir construction, play a dominant role in the decrease of sediment load. The decrease in sediment supply from the Pearl River should be paid special attention because it may cause serious impacts on the river delta and the coastal ocean.

  4. Impacts of Hurricane Katrina on floodplain forests of the Pearl River: Chapter 6A in Science and the storms-the USGS response to the hurricanes of 2005

    USGS Publications Warehouse

    Faulkner, Stephen; Barrow, Wylie; Couvillion, Brady R.; Conner, William; Randall, Lori; Baldwin, Michael

    2007-01-01

    Floodplain forests are an important habitat for Neotropical migratory birds. Hurricane Katrina passed through the Pearl River flood plain shortly after making landfall. Field measurements on historical plots and remotely sensed data were used to assess the impact of Hurricane Katrina on the structure of floodplain forests of the Pearl River.

  5. Coupled 1D-3D hydrodynamic modelling, with application to the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Twigt, Daniel J.; de Goede, Erik D.; Zijl, Firmijn; Schwanenberg, Dirk; Chiu, Alex Y. W.

    2009-12-01

    modelling of complex coastal waters and river network systems, whilst the advantages of both systems are maintained and used in an optimal and computationally efficient way. The coupled 1D-3D system is used to model the flows in the Pearl River Delta (Guangdong, China), which are determined by the interaction of the upstream network of the Pearl River and the open waters of the South China Sea. The highly complex upstream river network is modelled in 1D, simulating river discharges for the dry and wet monsoon periods. The 3D coastal model simulates the flow due to the external (ocean) periodic tidal forcing, the salinity distribution for both dry and wet seasons, as well as residual water levels (sea level anomalies) originating from the South China Sea. The model is calibrated and its performance extensively assessed against field measurements, resulting in a mean root mean square (RMS) error of below 6% for water levels over the entire Pearl River Delta. The model also represents both the discharge distribution over the river network and salinity transport processes with good accuracy, resolving the discharge distribution over the main branches of the river network within 5% of reported annual mean values and RMS errors for salinity in the range of 2 ppt (dry season) to 5 ppt (wet season).

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

    PubMed

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

    2013-10-01

    Rapid economic growth in South China (including Guangdong Province, Hong Kong, and Macau), particularly within the Pearl River Delta region, has resulted in severe pollution of the natural eco-environment in the last three decades. Large amounts of monitoring data on organic pollution in the Pearl River Delta have been accumulated, which allows us to conduct a fairly comprehensive assessment of the state of the Pearl River Delta and elucidate spatial and temporal patterns of pollution on a regional scale. Of various causes for environmental deterioration, negative impact from persistent organic pollutants (POPs) is a global concern. This review examines the current levels and distribution patterns of several POPs, namely DDT (and its metabolites DDD and DDE), hexachlorocyclohexanes, and polybrominated diphenyl ethers, in various environmental compartments of South China. The general information on environmental occurrence, regional behaviors, ecological effects, and human exposure of these POPs in this region are reviewed. PMID:23245873

  7. Distribution characteristics of transparent exopolymer particles in the Pearl River estuary, China

    NASA Astrophysics Data System (ADS)

    Sun, Cui-Ci; Wang, You-Shao; Li, Qian P.; Yue, Wei-Zhong; Wang, Yu-Tu; Sun, Fu-Lin; Peng, Ya-Lan

    2012-12-01

    Distribution of Transparent Exopolymer Particles (TEP) in the Pearl River estuary, China, was investigated during two cruises in August 2009 and January 2010. TEPcolor concentrations were 521.5-1727.4 μg Xeq.L-1 (μg Gum Xanthan equivalent liter-1) in August 2009 and 88.7-1586.9 μg Xeq.L-1 in January 2010, respectively. The size of TEP generally increased in the seaward along the longitudinal section with the dominant size of 2-40 μm during the cruises. Experimental work suggested that both concentration and size of TEP increased with Ca2+ concentration (from 0.8 mmol L-1 to 10 mmol L-1). In the field study, Ca2+ concentration had a positive correlation with TEPcolor concentration in the surface layer with salinity <16. Decrease of TEP concentration seaward from intermediary salinity was partly due to dilution of seawater as well as enhanced aggregation and sedimentation of TEP via increasing divalent cation concentration. TEP concentration and turbidity maximum coexisted at the tip of salt wedge in the bottom layer during the wet season, and positive correlation between TEP and turbidity was observed in the winter. Relationships between TEP and turbidity suggested the important contribution of TEP aggregation to flocculation and sedimentation of particles in estuaries. Different pattern of TEP during two cruises can be attributed to physical process (i.e., mixing type) in estuaries. These findings indicated that formation and distribution of TEP were largely influenced by interaction between physical and biogeochemical processes in the Pearl River estuary. A conceptual model for TEP formation and distribution in the Pearl River estuary was developed.

  8. Quality of water in the Pearl River, Jackson to Byram, Mississippi, September 21-22, 1976

    USGS Publications Warehouse

    Bednar, Gene A.

    1980-01-01

    The Pearl River in Mississippi, entering the study reach at site 1 at Jackson, was generally higher in dissolved-oxygen concentrations and lower in dissolved-solids, nutrients, and biochemical oxygen demands than at site 13 at Byram 11.8 miles downstream of site 1 and about 11 river miles downstream of treated sewage inflow. The dissolved oxygen concentrations of the water ranged from 6.4 to 7.8 milligrams per liter at site 1, and from 4.9 to 7.4 milligrams per liter at site 13. The average dissolved-solids concentrations were 60 and 97 milligrams per liter at sites 1 and 13, respectively. The average dissolved-solids load increased downstream about 35 tons per day. The average loads of 5-day biochemical oxygen demand, total phosphorus, and ammonia increased downstream about 2, 0.7, and 0.6 tons per day, respectively. The water in the study reach contained color, total iron, and manganese concentrations that exceeded limits recommended for public water supplies. Trace amounts of some pesticides and minor elements were present in both the water and bottom material at sites 1 and 13. The concentrations of most dissolved constituents were below recommended limits during the study and the Pearl River in the study reach may be considered usable for many purposes. (USGS)

  9. Urban growth and environmental impacts in Jing-Jin-Ji, the Yangtze, River Delta and the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Haas, Jan; Ban, Yifang

    2014-08-01

    This study investigates land cover changes, magnitude and speed of urbanization and evaluates possible impacts on the environment by the concepts of landscape metrics and ecosystem services in China's three largest and most important urban agglomerations: Jing-Jin-Ji, the Yangtze River Delta and the Pearl River Delta. Based on the classifications of six Landsat TM and HJ-1A/B remotely sensed space-borne optical satellite image mosaics with a superior random forest decision tree ensemble classifier, a total increase in urban land of about 28,000 km2 could be detected alongside a simultaneous decrease in natural land cover classes and cropland. Two urbanization indices describing both speed and magnitude of urbanization were derived and ecosystem services were calculated with a valuation scheme adapted to the Chinese market based on the classification results from 1990 and 2010 for the predominant land cover classes affected by urbanization: forest, cropland, wetlands, water and aquaculture. The speed and relative urban growth in Jing-Jin-Ji was highest, followed by the Yangtze River Delta and Pearl River Delta, resulting in a continuously fragmented landscape and substantial decreases in ecosystem service values of approximately 18.5 billion CNY with coastal wetlands and agriculture being the largest contributors. The results indicate both similarities and differences in urban-regional development trends implicating adverse effects on the natural and rural landscape, not only in the rural-urban fringe, but also in the cities' important hinterlands as a result of rapid urbanization in China.

  10. Fluvial Responses to Growth Faulting in the West Pearl River, Louisiana

    NASA Astrophysics Data System (ADS)

    Prosser, S. A.; Yeager, K. M.

    2015-12-01

    The Pearl River Delta (PRD) in southeastern Louisiana is an actively deforming deltaic complex displaying surface and near-surface evidence of growth faulting. Active growth faults in these environments are rarely identified at the surface, in part because the downthrown blocks often experience increased rates of sediment deposition leading to an obscured and low-relief, or entirely absent, surface expression. Faulting can be expressed in fluvial systems as changes in channel gradient, which often result in coincident changes in channel sinuosity, migration rates, planform deflections, and/or ponding features within the deformed zone. The study area is focused on a meander bend of the West Pearl River (WPR). The nature of the meander bend suggests the likely presence of a short growth fault controlling channel morphology. This research tested the hypotheses that active near-surface growth faulting is constraining the tortuous meander bend of the WPR and that growth faults, where present and active, are strongly coupled to channel meander planform changes and marsh vertical accretion rates in the PRD. Tools including shallow lithostratigraphy, use of fallout radionuclides (210Pb, 137Cs, 7Be) to quantify marsh vertical accretion rates, and a ~75 year record of WPR channel migration show that active growth faulting exists along the northern bend of the WPR with resultant lateral channel deflection. Evidence of this growth fault suggests further, eastward extension of the Baton Rouge Fault Zone (BRFZ) into the PRD

  11. Loess-like deposits in the Pearl River delta area, southeast China

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Chen, Guoneng; Peng, Zhuolun; Grapes, Rodney

    2015-12-01

    A layer of yellow silt is widely distributed in the late Quaternary succession of the Pearl River delta, southeast China. A representative section at Xi Lingang was analyzed using particle size analysis, scanning electron microscope observation, geochemical analysis and OSL dating to determine the characteristics and genesis of the yellow silt. Grain size composition of the yellow silt is homogeneous and comparable to typical north China loess (10-50 μm as "basic grain size group", <5 μm as "secondary grain size group"). Grain size parameters and frequency distribution curves of the yellow silt also indicate an aeolian origin. Aeolian micro-textures with subangular-subrounded grains characterized by dished surface collision pits during wind transportation. Homogeneous major element composition of the yellow silt suggests that the dust has been well mixed and sorted prior to deposition, a typical feature of aeolian origin, but Chemical Index of Alteration values indicate that the yellow silt has suffered intense weathering after deposition. Five OSL dates obtained in this study and other geochronological data indicate that the yellow silt has a Last Glacial Maximum age. The grain size of loess across China becomes finer from northwest to southeast because of increasing transportation distance, and implies that the loess component of the yellow silt in the Pearl River delta area is also derived from a northwest China provenance.

  12. 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

  13. Transfer of Cadmium from Soil to Vegetable in the Pearl River Delta area, South China

    PubMed Central

    Zhang, Huihua; Chen, Junjian; Zhu, Li; Yang, Guoyi; Li, Dingqiang

    2014-01-01

    The purpose of this study was to investigate the regional Cadmium (Cd) concentration levels in soils and in leaf vegetables across the Pearl River Delta (PRD) area; and reveal the transfer characteristics of Cadmium (Cd) from soils to leaf vegetable species on a regional scale. 170 paired vegetables and corresponding surface soil samples in the study area were collected for calculating the transfer factors of Cadmium (Cd) from soils to vegetables. This investigation revealed that in the study area Cd concentration in soils was lower (mean value 0.158 mg kg−1) compared with other countries or regions. The Cd-contaminated areas are mainly located in west areas of the Pearl River Delta. Cd concentrations in all vegetables were lower than the national standard of Safe vegetables (0.2 mg kg−1). 88% of vegetable samples met the standard of No-Polluted vegetables (0.05 mg kg−1). The Cd concentration in vegetables was mainly influenced by the interactions of total Cd concentration in soils, soil pH and vegetable species. The fit lines of soil-to-plant transfer factors and total Cd concentration in soils for various vegetable species were best described by the exponential equation (), and these fit lines can be divided into two parts, including the sharply decrease part with a large error range, and the slowly decrease part with a low error range, according to the gradual increasing of total Cd concentrations in soils. PMID:25247431

  14. Quantitative analysis and simulation of land use changes in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Zhang, Honghui; Zeng, Yongnian; Zou, Bin; Xiao, Pengfeng; Hu, Deyong; Peng, Jianchao

    2007-06-01

    This paper analyzes and simulates the land use changes in the Pearl River Delta, China, using Longgang City as a case study. The region has pioneered the nation in economic development and urbanization process. Tremendous land use changes have been witnessed since the economic reform in 1978. Land use changes are analyzed and simulated by using stochastic cellular automata model, land use trajectories analysis, spatial indices and multi-temporal TM images of Longgang City (TM1987, TM1991, TM1995, TM1999, TM2003, TM2005) in order to understand how urbanization has transformed the non-urban land to urban land and estimate the consequent environment and ecological impacts in this region. The analysis and simulation results show that urban land continues to sprawl along road and fringe of towns, and concomitant to this development is the loss of agricultural land, orchards and fish ponds. This study provides new evidence with spatial details about the uneven land development in the Pearl River Delta.

  15. 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. PMID:25889539

  16. 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

  17. Phytoplankton dynamics in and near the highly eutrophic Pearl River Estuary, South China Sea

    NASA Astrophysics Data System (ADS)

    Qiu, Dajun; Huang, Liangmin; Zhang, Jianlin; Lin, Senjie

    2010-02-01

    The dynamics of size-fractionated phytoplankton along the salinity gradient in the Pearl River Estuary and the adjacent near-shore oceanic water was investigated using microscopic, flow cytometric, and chlorophyll analyses in the early spring (March) and early autumn (September) of 2005. In the inner part of the estuary where salinity was less than 30, the phytoplankton community was dominated by micro- and nano-sized (3-200 μm) cells, particularly the diatom Skeletonema costatum, both in early spring and early autumn. In areas where salinity >30, including the mixing zone and nearshore oceanic water, micro- and nano-sized cell populations dominated the phytoplankton assemblage during early spring when influence of river discharge was minimal, whereas pico-sized (≤3 μm) cell populations were dominant during early autumn as a result of strong river discharge in the summer, with Synechococcus and pico-eukaryotes being predominant. Picophytoplankton were two orders of magnitude more abundant in early autumn (10 6 cells mL -1) than in early spring in the nearshore oceanic water. Nutrients delivered by freshwater input to the estuary were pushed toward high salinity (>30) areas as a result of short residence time, exerting a strong influence on phytoplankton abundance, especially picophytoplankton in the nearshore, otherwise oligotrophic, water. Influenced by high abundance of DIN and limitation in phosphorus, picophytoplankton in the adjacent nearshore oceanic water rose to prominence seasonally. Our results indicate that eutrophication in the Pearl River Estuary not only stimulates the growth of S. costatum in the nutrient-rich areas of the estuary but also appears to promote the growth of Synechococcus and pico-eukaryotes in the adjacent usually oligotrophic oceanic water at least during our autumn cruise.

  18. 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. PMID:17874763

  19. River Basin Standards Interoperability Pilot

    NASA Astrophysics Data System (ADS)

    Pesquer, Lluís; Masó, Joan; Stasch, Christoph

    2016-04-01

    There is a lot of water information and tools in Europe to be applied in the river basin management but fragmentation and a lack of coordination between countries still exists. The European Commission and the member states have financed several research and innovation projects in support of the Water Framework Directive. Only a few of them are using the recently emerging hydrological standards, such as the OGC WaterML 2.0. WaterInnEU is a Horizon 2020 project focused on creating a marketplace to enhance the exploitation of EU funded ICT models, tools, protocols and policy briefs related to water and to establish suitable conditions for new market opportunities based on these offerings. One of WaterInnEU's main goals is to assess the level of standardization and interoperability of these outcomes as a mechanism to integrate ICT-based tools, incorporate open data platforms and generate a palette of interchangeable components that are able to use the water data emerging from the recently proposed open data sharing processes and data models stimulated by initiatives such as the INSPIRE directive. As part of the standardization and interoperability activities in the project, the authors are designing an experiment (RIBASE, the present work) to demonstrate how current ICT-based tools and water data can work in combination with geospatial web services in the Scheldt river basin. The main structure of this experiment, that is the core of the present work, is composed by the following steps: - Extraction of information from river gauges data in OGC WaterML 2.0 format using SOS services (preferably compliant to the OGC SOS 2.0 Hydrology Profile Best Practice). - Model floods using a WPS 2.0, WaterML 2.0 data and weather forecast models as input. - Evaluation of the applicability of Sensor Notification Services in water emergencies. - Open distribution of the input and output data as OGC web services WaterML, / WCS / WFS and with visualization utilities: WMS. The architecture

  20. 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...

  1. The Quality of Student Experiences in Traditionally Scheduled Courses versus Block Scheduled Courses at Pearl River Community College

    ERIC Educational Resources Information Center

    Alsobrooks, David Scott

    2010-01-01

    The purpose of this study was to determine if students at Pearl River Community College (PRCC) achieve significantly different self-reported Quality of Effort levels when enrolled in block scheduled programs than students enrolled in traditionally scheduled programs. This study focuses on Career and Technical Education (CTE) programs at PRCC in…

  2. Role of photoexcited nitrogen dioxide chemistry on ozone formation and emission control strategy over the Pearl River Delta, China

    EPA Science Inventory

    A new hydroxyl radical formation pathway via photo-excited nitrogen dioxide chemistry is incorporated into a chemistry-only box model as well as a 3D air quality model to examine its potential role on ozone formation and emission control strategy over the Pearl River Delta region...

  3. 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…

  4. Examining the Impact of Nitrous Acid Chemistry on Ozone and PM over the Pearl River Delta Region

    EPA Science Inventory

    The impact of nitrous acid (HONO) chemistry on regional ozone and particulate matter in Pearl River Delta region was investigated using the community multiscale air quality (CMAQ) modeling system and the CB05 mechanism. Model simulations were conducted for a ten-day period in Oct...

  5. Impact of river-tide dynamics on the residual water level slope and residual sediment transport in the Pearl River channel networks

    NASA Astrophysics Data System (ADS)

    Cai, Huayang; Zhang, Zihao; Yang, Qingshu; Ou, Suying

    2016-04-01

    Large-scale delta systems, such as the Rhine-Meuse delta, the Mississippi River delta, the Mekong delta, the Yangtze delta and the Pearl River delta etc., usually feature a typical channel networks, where individual channels are interrelated through a networks system, resulting in both longitudinal and transverse variations of residual water level slope (averaged over a lunar day) caused by the river-tide interplay. Enhancing our insight of river-tide dynamics in these channel networks has vital importance for the protection and management of estuarine environment since river-tide interplay is closely related to sediment transport, water quality, water utilization and estuarine ecosystem. In this study, we investigate the impact of river-tide dynamics on the temporal-spatial changes of flow and suspended sediment load in terms of residual water level slope and residual sediment transport in the Pearl River channel networks, which is one of the complex channel networks in the world. Making use of a nonstationary harmonic analysis (NS_TIDE), the continuous time series observations of velocity covering a spring-neap cycle in 1999 (representing flood season) and 2001 (representing dry season) collected from around 60 stations in the Pearl River channel networks have been used to extract the temporal-spatial changes in residual velocity and tidal properties (including amplitudes and phases) as a function of variable river flow debouching into the delta. On the basis of harmonic analysis, the tidally averaged friction is decomposed into contributions made by riverine forcing alone, river-tide interaction and tidal asymmetry using Chebyshev polynomials approach. It is shown that river flow enhances friction via river-tide interaction, which increases the residual water level slope that influences the distribution of suspended sediment load in the Pearl River channel networks.

  6. Effects of proposed highway embankment modifications on water-surface elevations in the lower Pearl River flood plain near Slidell, Louisiana

    USGS Publications Warehouse

    Gilbert, J.J.; Schuck-Kolben, R. E.

    1987-01-01

    Major flooding in the lower Pearl River basin in recent years has caused extensive damage to homes and highways in the area. In 1980 and 1983, Interstate Highway 10 and U.S. Highway 190 were overtopped. In 1983, the Interstate Highway 10 crossing was seriously damaged by the flood. The U.S. Geological Survey, in cooperation with the Louisiana Department of Transportation and Development, Office of Highways, used a two-dimensional finite-element surface-water flow model to evaluate the effects the proposed embankment modifications at Interstate Highway 10 and U.S. Highway 90 on the water-surface elevations in the lower Pearl River flood plain near Slidell, Louisiana. The proposed modifications that were considered for the 1983 flood are: (1) Removal of all highway embankments, the natural condition, (2) extension of the West Pearl River bridge by 1,000 feet at U.S. Highway 90, (3) construction of a new 250-foot bridge opening in the U.S. Highways 190 and 90, west of the intersection of the highways. The proposed highway bridge modifications also incorporated lowering of ground-surface elevations under the new bridges to sea level. The modification that provided the largest reduction in backwater, about 35 percent, was a new bridge in Interstate Highway 10. The modification of the West Pearl River bridge at U.S. Highway 90 and replacement of the bridge in U.S. Highway 190 provide about a 25% reduction in backwater each. For the other modification conditions that required structural modifications, maximum backwater computed on the west side of the flood plain ranges from 0.0 to 0.8 foot and on the east side from 0.0 to 0.6 foot. Results show that although backwater is greater on the west side of the flood plain than on the east side, upstream of highway embankments, backwater decreases more rapidly in the upstream direction on the west side of the flood plain than on the east side. Analysis of the proposed modifications indicates that backwater would still occur on

  7. The spatial-temporal distribution of particulate organic carbon in the Pearl River Estuary

    NASA Astrophysics Data System (ADS)

    Liu, Dong; Zhu, Qiankun; Chen, Jianyu; Gong, Fang; Wei, Ji-An

    2015-10-01

    Particulate Organic Carbon (POC) plays an important role in sink of atmospheric CO2, global carbon cycle, etc. Around river estuary, POC is sourced from terrestrial ecosystem and aquatic ecosystem; its distribution features might be complex and likely to change with time. Based on in-situ samples from four seasonal cruises, we discussed spatial-temporal distribution and remote sensing monitoring of POC concentration in the Pearl River Estuary (PRE). Being affected by larger discharge from the Pearl River, surface POC concentrations in summer were usually higher than those in other three seasons, similar, in the PRE. However, because of sediment resuspension, POC concentrations at the bottom layer were higher than those at the surface layer. Taking the PRE as an example, remote sensing monitoring of POC concentration in case II water around estuary was also discussed. On the one hand, on the basis of Chlorophyll-a (Chl-a) and Total Suspended Matter (TSM) concentrations inversed by published algorithms, we can estimate surface POC concentration through multiple linear regression equation: POC=0.042*Chl-a+0.014*TSM+0.1595, R=0.9156. On the other hand, great relationships between surface POC concentrations and total particle absorption coefficient at 667nm (TPabs(667)) and 678nm (TPabs(678)) were also found: POC=3.813*TPabs(667)+0.0684, R=0.8769 and POC=3.9175*TPabs(678)+0.0624, R=0.8745. They implied the possibility of estuarine POC monitoring from space through remote sensing reflectance at 667nm or 678nm.

  8. Tritium hydrology of the Mississippi River basin

    USGS Publications Warehouse

    Michel, R.L.

    2004-01-01

    In the early 1960s, the US Geological Survey began routinely analysing river water samples for tritium concentrations at locations within the Mississippi River basin. The sites included the main stem of the Mississippi River (at Luling Ferry, Louisiana), and three of its major tributaries, the Ohio River (at Markland Dam, Kentucky), the upper Missouri River (at Nebraska City, Nebraska) and the Arkansas River (near Van Buren, Arkansas). The measurements cover the period during the peak of the bomb-produced tritium transient when tritium concentrations in precipitation rose above natural levels by two to three orders of magnitude. Using measurements of tritium concentrations in precipitation, a tritium input function was established for the river basins above the Ohio River, Missouri River and Arkansas River sampling locations. Owing to the extent of the basin above the Luling Ferry site, no input function was developed for that location. The input functions for the Ohio and Missouri Rivers were then used in a two-component mixing model to estimate residence times of water within these two basins. (The Arkansas River was not modelled because of extremely large yearly variations in flow during the peak of the tritium transient.) The two components used were: (i) recent precipitation (prompt outflow) and (ii) waters derived from the long-term groundwater reservoir of the basin. The tritium concentration of the second component is a function of the atmospheric input and the residence times of the groundwaters within the basin. Using yearly time periods, the parameters of the model were varied until a best fit was obtained between modelled and measured tritium data. The results from the model indicate that about 40% of the flow in the Ohio River was from prompt outflow, as compared with 10% for the Missouri River. Mean residence times of 10 years were calculated for the groundwater component of the Ohio River versus 4 years for the Missouri River. The mass flux of

  9. Metabolic principles of river basin organization

    NASA Astrophysics Data System (ADS)

    Rodriguez-Iturbe, I.; Caylor, K. K.; Rinaldo, A.

    2011-12-01

    The metabolism of a river basin is defined as the set of processes through which the basin maintains its structure and responds to its environment. Green (or biotic) metabolism is measured via transpiration and blue (or abiotic) metabolism through runoff. A principle of equal metabolic rate per unit area throughout the basin structure is developed and tested in a river basin characterized by large heterogeneities in precipitation, vegetation, soil, and geomorphology. This principle is suggested to have profound implications for the spatial organization of river basin hydrologic dynamics, including the minimization of energy expenditure known to control the scale-invariant characteristics of river networks over several orders of magnitude. Empirically derived, remarkably constant rates of average transpiration per unit area through the basin structure lead to a power law for the probability distribution of transpiration from a randomly chosen subbasin. The average runoff per unit area, evaluated for subbasins of a wide range of topological magnitudes, is also shown to be remarkably constant independently of size. A similar result is found for the rainfall after accounting for canopy interception. Allometric scaling of metabolic rates with size, variously addressed in the biological literature and network theory under the label of Kleiber's law, is similarly derived. The empirical evidence suggests that river basin metabolic activity is linked with the spatial organization that takes place around the drainage network and therefore with the mechanisms responsible for the fractal geometry of the network, suggesting a new coevolutionary framework for biological, geomorphological, and hydrologic dynamics.

  10. Metabolic principles of river basin organization.

    PubMed

    Rodriguez-Iturbe, Ignacio; Caylor, Kelly K; Rinaldo, Andrea

    2011-07-19

    The metabolism of a river basin is defined as the set of processes through which the basin maintains its structure and responds to its environment. Green (or biotic) metabolism is measured via transpiration and blue (or abiotic) metabolism through runoff. A principle of equal metabolic rate per unit area throughout the basin structure is developed and tested in a river basin characterized by large heterogeneities in precipitation, vegetation, soil, and geomorphology. This principle is suggested to have profound implications for the spatial organization of river basin hydrologic dynamics, including the minimization of energy expenditure known to control the scale-invariant characteristics of river networks over several orders of magnitude. Empirically derived, remarkably constant rates of average transpiration per unit area through the basin structure lead to a power law for the probability distribution of transpiration from a randomly chosen subbasin. The average runoff per unit area, evaluated for subbasins of a wide range of topological magnitudes, is also shown to be remarkably constant independently of size. A similar result is found for the rainfall after accounting for canopy interception. Allometric scaling of metabolic rates with size, variously addressed in the biological literature and network theory under the label of Kleiber's law, is similarly derived. The empirical evidence suggests that river basin metabolic activity is linked with the spatial organization that takes place around the drainage network and therefore with the mechanisms responsible for the fractal geometry of the network, suggesting a new coevolutionary framework for biological, geomorphological, and hydrologic dynamics. PMID:21670259

  11. Rivers Run Through It: Discovering the Interior Columbia River Basin.

    ERIC Educational Resources Information Center

    Davis, Shelley; Wojtanik, Brenda Lincoln; Rieben, Elizabeth

    1998-01-01

    Explores the Columbia River Basin, its ecosystems, and challenges faced by natural resource managers. By studying the basin's complexity, students can learn about common scientific concepts such as the power of water and effects of rain shadows. Students can also explore social-scientific issues such as conflicts between protecting salmon runs and…

  12. RED RIVER BASIN BIOLOGICAL MONITORING WORKGROUP

    EPA Science Inventory

    The goal of this project is to improve coordination of biological monitoring efforts in the Red River Basin. This is to be accomplished through coordination of a study to develop sampling protocols for macroinvertebrates in the main stream and lower tributaries of the Red River....

  13. Circulatory mobility in post-Mao China: temporary migrants in Kaiping county, Pearl River Delta region.

    PubMed

    Woon, Y

    1993-01-01

    "Since the 1980s, it has been possible for the Chinese peasant household to diversify its economic base by making use of its social networks to place members in a distant community as migrant workers. Through a microstudy of 50 such migrants in Kaiping County in the Pearl River Delta region, this article illustrates the interplay between macro, meso, and micro factors in the causes and processes of circulatory mobility in post-Mao China. It is found that Hong Kong's search for cheap labor, the PRC's household registration system, and Kaiping's strong localism provide the context in which migrants and their households have to adjust. The particular behavior pattern of these migrants also bears the stamp of their rational household decision-making processes as well as their feelings of moral obligation toward their kin in their community of origin." PMID:12287570

  14. Induction of lipids and resultant FAME profiles of microalgae from coastal waters of Pearl River Delta.

    PubMed

    Daroch, Maurycy; Shao, Congcong; Liu, Ying; Geng, Shu; Cheng, Jay J

    2013-10-01

    This article presents a study on identification, cultivation and characterisation of microalgal strains from the coastal waters of the Pearl River Delta in Guangdong, China. Thirty-seven identified strains belong to the families: Chlorellaceae, Scotiellocystoidaceae, Scenedesmaceae,Selenastraceae,Micractiniaceae, Coccomyxaceae, Trebouxiaceae and Chlorococcaceae. Of isolated strains, Hindakia PKUAC 169 was selected for lipid induction using two methods: nitrogen starvation and salt stress. After derivatisation of algal lipids through in situ transesterification, lipid profiles of the alga under the two methods were analysed. The results have shown that both lipid yield and fatty acid profiles vary with the methods. Of the two tested methods of inducing lipid production, salt stress yielded three-fold higher lipid productivity than nitrogen starvation. The lipids are predominantly composed of C14-C18 fatty acids, which are favourable for biodiesel production. Moreover, the content of polyunsaturated fatty acids was below the limit of 12% set by EN14214 biodiesel standard. PMID:23933027

  15. A dinoflagellate Cochlodinium geminatum bloom in the Zhujiang (Pearl) River estuary in autumn 2009

    NASA Astrophysics Data System (ADS)

    Ke, Zhixin; Huang, Liangmin; Tan, Yehui; Song, Xingyu

    2012-05-01

    A severe Cochlodinium geminatum red tide (>300 km2) was observed in the Zhujiang (Pearl) River estuary, South China Sea in autumn 2009. We evaluated the environmental conditions and phytoplankton community structure during the outbreak. The red tide water mass had significantly higher dissolved inorganic phosphate (DIP), ammonia, and temperature, but significantly lower nitrite, nitrate, dissolved inorganic nitrogen (DIN), and DIN/DIP relative to the non-red-tide zones. The phytoplankton assemblage was dominated by dinoflagellates and diatoms during the red tide. C. geminatum was the most abundant species, with a peak density of 4.13×107 cell/L, accounting for >65% of the total phytoplankton density. The DIN/DIP ratio was the most important predictor of species, accounting for 12.45% of the total variation in the phytoplankton community. Heavy phosphorus loading, low precipitation, and severe saline intrusion were likely responsible for the bloom of C. geminatum.

  16. Hong Kong at the Pearl River Estuary: A hotspot of microplastic pollution.

    PubMed

    Fok, Lincoln; Cheung, P K

    2015-10-15

    Large plastic (>5mm) and microplastic (0.315-5mm) debris were collected from 25 beaches along the Hong Kong coastline. More than 90% consisted of microplastics. Among the three groups of microplastic debris, expanded polystyrene (EPS) represented 92%, fragments represented 5%, and pellets represented 3%. The mean microplastic abundance for Hong Kong was 5595items/m(2). This number is higher than international averages, indicating that Hong Kong is a hotspot of marine plastic pollution. Microplastic abundance was significantly higher on the west coast than on the east coast, indicating that the Pearl River, which is west of Hong Kong, may be a potential source of plastic debris. The amounts of large plastic and microplastic debris of the same types (EPS and fragments) were positively correlated, suggesting that the fragmentation of large plastic material may increase the quantity of beach microplastic debris. PMID:26233305

  17. Stress measuring and monitoring for main tower of Guangzhou Pearl River HuangPu Bridge

    NASA Astrophysics Data System (ADS)

    Wang, Wei-feng; Liang, Jian-dong

    2008-11-01

    Stress measuring and monitoring play an important role in the construction monitor for HuangPu Bridge in Guangzhou Pearl River, and it ensure the construction safe and normal status of finished bridge. The strain of concrete includes not only the elastic strain resulted from the load effect, but also the non-elastic strain resulted from the creep and shrinkage of concrete. The difficulty for separating creep and shrinkage is the determining for the creep coefficient. A partial site test on creep and shrinkage for the concrete is carried out. The parameters of prediction model CEB-FIP1990 are modified, and some expressions for creep and shrinkage, which are suitable for this project, are acquired. Based on the linearity principle of superposition, the concrete's elastic stress is calculated, and the creep and shrinkage can be separated more accurately.

  18. Cruise observation and numerical modeling of turbulent mixing in the Pearl River estuary in summer

    NASA Astrophysics Data System (ADS)

    Pan, Jiayi; Gu, Yanzhen

    2016-06-01

    The turbulent mixing in the Pearl River estuary and plume area is analyzed by using cruise data and simulation results of the Regional Ocean Model System (ROMS). The cruise observations reveal that strong mixing appeared in the bottom layer on larger ebb in the estuary. Modeling simulations are consistent with the observation results, and suggest that inside the estuary and in the near-shore water, the mixing is stronger on ebb than on flood. The mixing generation mechanism analysis based on modeling data reveals that bottom stress is responsible for the generation of turbulence in the estuary, for the re-circulating plume area, internal shear instability plays an important role in the mixing, and wind may induce the surface mixing in the plume far-field. The estuary mixing is controlled by the tidal strength, and in the re-circulating plume bulge, the wind stirring may reinforce the internal shear instability mixing.

  19. Coastal Storm surge flooding impact under different climate scenarios in Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Li, Li; Boehner, Juergen

    2015-04-01

    The Pearl River Delta is highly vulnerable due to the low altitude and frequent typhoon attack. Flooding poses a severe risk of loss of human life and infrastructural values in this area. This study aims to estimate the inundation area and quantities the economic loss. D-Flow flexible mesh model is employed to simulate the storm surge flooding inundation area under three different typhoon scenarios. D-Flow flexible mesh is the first numerical model combined structure grid and unstructured grid in the world, which is also the first application in the most complicated watercourse in China. The model is calibrated using in-site measured discharge and water level. The inundation area is validated against satellite image. Three typhoon scenarios with different characteristics will be examined. Results of this research will help to relief the flooding loss, also the results would be useful for land use planning and sustainable development in the coastal and delta area.

  20. Drainage divides, Massachusetts-Hudson River basin

    USGS Publications Warehouse

    Wandle, S. William, Jr.

    1982-01-01

    Drainage boundaries for selected subbasins in northern Berkshire County, Massachusetts, are delineated on five topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for rivers where the drainage area is greater than 3 square miles. Successive sites are indicated where the intervening area is at least 6 square miles on tributary streams and 10 square miles along the Hoosic or North Branch Noosic Rivers. (USGS)

  1. Time trends of polybrominated diphenyl ethers in sediment cores from the Pearl River Estuary, South China.

    PubMed

    Chen, She-Jun; Luo, Xiao-Jun; Lin, Zhen; Luo, Yong; Li, Ke-Chang; Peng, Xian-Zhi; Mai, Bi-Xian; Ran, Yong; Zeng, Eddy Y

    2007-08-15

    The present study provides information on the time trend of PBDEs in three sediment cores from the Pearl River Estuary (PRE), South China, using 210Pb dating technique. The sigmaPBDEs (except for BDE 209) concentrations in all sediment cores increased gradually from the bottom (mid-1970s) to the middle layer (later 1980s and early 1990s) followed by different temporal trends in different locations to the surface sediments, reflecting the variations in the consumption of commercial penta-BDEs mixture in different regions of the Pearl River Delta. The BDE 209 concentrations remained constant until 1990 and thereafter increased exponentially to the present, with doubling times of 2.6 +/- 0.5-6.4 +/- 1.6 years, suggesting the increasing market demands for deca-BDE mixture after 1990 in China. The inventories of sigmaPBDEs and BDE 209 in sediments of the PRE were 56.0 and 368.2 ng cm(-2), respectively, and the total burden of PBDEs in the PRE were estimated at 8.6 metric tons. The current sigmaPBDEs and BDE 209 fluxes to the PRE were 2.1 and 29.7 ng cm(-2) yr(-1), respectively. The concurrent increase of BDE 209 fluxes and the annual gross industrial output values of electronics manufacturing revealed that the rapid growth of electronics manufacturing in this region since the early 1990s was responsible for the sharp rise of BDE 209 fluxes in the past decade. The PBDE congener compositions of the cores indicated the various input pathways for PBDEs transport to different locations of the estuary. PMID:17874760

  2. [Integrated assessment of eco-environmental vulnerability in Pearl River Delta based on RS and GIS].

    PubMed

    Xu, Qing-Yong; Huang, Mei; Liu, Hong-Sheng; Yan, Hui-Min

    2011-11-01

    Based on the remote sensing data and with the help of geographic information system, an integrated assessment was conducted on the eco-environmental vulnerability of Pearl River Delta in 2004-2008. Spatial principal component analysis was used to generate the evaluation indicators, and analytic hierarchy process (AHP) was applied to determine the weights of the evaluation factors. The reasons causing the vulnerability of the eco- environment in Pearl River Delta were discussed. In the study area, its middle part was the most vulnerable region, occupying 34.0% of the total, eastern part was the moderately vulnerable region, accounting for 25.5%, and western part was the lightly and slightly vulnerable areas, accounting for 28.7 and 11.8%, respectively. Totally, the moderately and lightly vulnerable areas occupied 54.2%, indicating that a majority of the Delta was under moderate and light vulnerability. The natural factors affecting the eco-environmental vulnerability of the Delta were altitude, heavy rain days, water and soil erosion rate, flooded infield rate, normalized difference vegetation index (ND VI) and landscape diversity index, whereas the human factors were population density, waste discharge per unit area, exhaust emission per unit area, land use change, chemical fertilization intensity, pesticide application intensity, amount of motor vehicles possessed by ten thousands people, and index of environmental protection investment. The main characteristics of the extremely and heavily vulnerable regions were low altitude, high frequency of flood disaster, large flooded infield, serious vegetation degradation, high pollution level and low environment protection investment index. PMID:22303678

  3. 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.

  4. Paraguay river basin response to seasonal rainfall

    NASA Astrophysics Data System (ADS)

    Krepper, Carlos M.; García, Norberto O.; Jones, Phil D.

    2006-07-01

    The use of river flow as a surrogate to study climatic variability implies the assumption that changes in rainfall are mirrored and likely amplified in streamflow. This is probably not completely true in large basins, particularly those that encompass different climatic regions, like the Paraguay river basin. Not all the signals present in precipitation are reflected in river flow and vice versa. The complex relationship between precipitation and streamflow could filter some signals and introduce new oscillatory modes in the discharge series. In this study the whole basin (1 095 000 km2) was divided into two sub-basins. The upper basin is upstream of the confluence with the River Apa and the lower basin is between the Apa river confluence and the Puerto Bermejo measuring station. The rainfall contribution shows a clear wet season from October to March and a dry season from April to September. A singular spectrum analysis (SSA) shows that there are trends in rainfall contributions over the upper and lower basins. Meanwhile, the lower basin only presents a near-decadal cycle (T 10 years). To determine the flow response to seasonal rainfall contributions, an SSA was applied to seasonal flow discharges at Puerto Bermejo. The seasonal flows, Q(t)O-M and Q(t)A-S, present high significant modes in the low-frequency band, like positive trends. In addition, Q(t)O-M presents a near-decadal mode, but only significant at the 77% level for short window lengths (M ≤ 15 years). Really, the Paraguay river flow is not a good surrogate to study precipitation variation. The low-frequency signals play an important role in the flow behaviour, especially during extreme events from the second half of the last century onwards.

  5. A coupling simulation based on a hydrodynamics and water quality model of the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Zhou, Nianqing; Westrich, Bernhard; Jiang, Simin; Wang, Yan

    2011-01-01

    SummaryThe rapid economic development has caused heavy pollution in the Pearl River Delta Region (PRDR) and neighboring regions. In order to investigate the polluted characteristics, a coupled modelling approach has been deployed and the study area in the Pear River Delta is divided into two modelling systems: a river network that is simulated by a 1D hydrodynamic and water quality model, and an estuary that is modelled by a 3D model. The 1D river network model is coupled with the 3D estuary model based on the mass conservation criteria. The hydrodynamic (HD) model is based on 1D hydrostatic shallow water equations, and is solved by the Alternating Direction Implicit Approach. The water quality (WQ) model component is based on advection-diffusion equations. Some physical and bio-chemical processes are included in the WQ model to address the water pollution problems by different pollution substances, in particular, to the chemical oxygen demand (COD). The water quality data of the main rivers from 2004 to 2007 were collected, processed and evaluated. Because no detailed water quality data in the river is available, the COD source pollution intensity in the water quality model is taking the pollutant load from the confluence of the main five outlets of the Pearl River Estuary (PRE) for 1996-2007 as surrogate. The results show that the pollutants from the PRDR have a large impact on the quality of the Hong Kong seawater and much more serious in the wet season with high river discharge. An insight of the flow and transportation mechanism in the river and estuary system has been obtained through the paper, and a reliable basis to control water pollution of the Pearl River Delta is provided in this paper.

  6. IAHS Symposium on Large River Basins

    NASA Astrophysics Data System (ADS)

    Frick, David M.

    The flow regime of large rivers is significantly influenced by man's activities, such as land use or river development. In other cases, there is evidence that climate change is the reason for modified flow regime. When basins are shared by a number of countries, the problems of hydrologic change become even more critical. Therefore, the social and economic consequences of changes in the flow regime of large river basins is far reaching,To improve the understanding of hydrologic processes and to investigate the availability of tools and methods that can be used to analyze the hydrological impacts of changes in flow, the International Association of Hydrologic Sciences (IAHS) and International Commission on Surface Water (ICSW) devoted its symposium, held at the August 1991 XXth General Assembly of the International Union of Geodesy and Geophysics (IUGG) in Vienna, Austria, to the theme “Hydrology for Water Management of Large River Basins.” The theme was divided into the four subtopics of water management and cooperation in large and/or international river basin: flow regimes and water management in relation to changes in climate, river development, and land use; water quality and sediment transport management in a large river environment; and operational flow and water quality forecasting. Both the general problem and organizational and operational aspects were investigated.

  7. Distribution of organophosphorus flame retardants in sediments from the Pearl River Delta in South China.

    PubMed

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

    2016-02-15

    Twelve organophosphorus flame retardants (PFRs) were identified in the sediments and the sediment core collected from the rivers and the estuary in the Pearl River Delta, with the aim of investigating their spatial and vertical distributions. The concentrations of PFRs ranged from 8.3 to 470 ng/g dry weight with high levels of PFRs in the urban area and the e-waste recycling region. Generally, TPhP, TCPP, TEHP, TCEP, and TBEP were the dominant compounds of the PFRs, the composition of which varied across the different regions, reflecting the different sources of PFRs. In the estuary, the PFRs mainly derived from the Xijiang River and the Shunde sections. Increased concentrations of halogen-containing PFRs have been observed in the upper layers of the sediment core. Conversely, relatively high concentrations of halogen-free PFRs were observed in the lower layers of the sediment core, indicating different usage patterns or environmental behaviors between the halogen and the non-halogen PFRs in the study area. PMID:26657357

  8. PCB contamination in soils of the Pearl River Delta, South China: levels, sources, and potential risks.

    PubMed

    Zhang, Haibo; Luo, Yongming; Teng, Ying; Wan, Hongfu

    2013-08-01

    Polychlorinated biphenyls (PCBs) contamination in tropical and sub-tropical areas and the associated risks have attracted great concern. A total of 69 samples representing five distinct land types were collected to assess PCB concentrations in the Pearl River Delta (PRD), South China, including spatial distributions in soils of the area, the probable anthropogenic sources, and related potential risks. PCBs concentrations in soils of the PRD ranged from 0.3 to 202 ng g(-1). More severe PCBs contamination was presented in the western part than in the eastern part of the PRD region. The PCBs were dominated by low-chlorinated biphenyls; however, the proportion of higher-chlorinated biphenyls was elevated with the influence of industrial activities. Principal component analysis indicated that PCBs contamination in soils of the PRD region was mainly associated with 1#PCBs, while 2#PCB and e-waste emission in South China also accounted for it partly, especially to the industrial activity severely impacted areas. Toxic equivalent (TEQ) of the dioxin-like PCBs in the soils indicated that higher risk of PCB contamination was presented in the Dongjiang River Valley (55 ng TEQ kg(-1), on average) than in the Xijiang River Valley, and were mostly contributed by the congener of PCB126. PMID:23354616

  9. Seasonal characterization and identification of dissolved organic matter (DOM) in the Pearl River, China.

    PubMed

    Zheng, Liuchun; Song, Zhaofeng; Meng, Peipei; Fang, Zhanqiang

    2016-04-01

    Dissolved organic matter (DOM) is considered to be one of active organic carbon components in river water, and its characteristics would affect quality of drinking water if such a river is used for the purpose. DOM in the Pearl River around metropolitan Guangzhou and its six fractions obtained by sequential resins separation and their percentage distribution of total organic carbon (TOC), the UV absorbance at 254 nm (UV254), and the specific ultraviolet absorbance (SUVA254) were determined. Meanwhile, fluorescence spectroscopy and Fourier transform infrared (FTIR) spectroscopy were used to examine the biodegradable and structural characteristics of DOM. The results showed that the values of TOC, UV254, and SUVA254 changed with season. Especially, SUVA254 was lower than 3 L (mg m)(-1), indicating that the hydrophilic fractions were the major components of the DOM. Furthermore, fluorescence spectroscopy revealed the dominant presence of humic-like, fulvic-like, and protein-like fluorophores. Fluorescence index (FI) in four seasons was associated with allochthonous DOM sources and biological DOM. FTIR spectroscopy suggested the feature of DOM with some specific groups (e.g., carbohydrate C-O, amid C═O). PMID:26711291

  10. Occurrence of endocrine-disrupting chemicals in riverine sediments from the Pearl River Delta, China.

    PubMed

    Gong, Jian; Ran, Yong; Chen, Di-Yun; Yang, Yu

    2011-01-01

    The endocrine-disrupting chemicals (EDCs) was investigated in 28 riverine sediments from the Pearl River system, China and analyzed by an ultrasonication extraction and GC-MS method. The concentrations of 4-tert-octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) in the sediments were in the ranges of <2.0-210, 107-16198 and <1.7-430 ng/g dw, respectively. The steroid estrogens estrone (E1) and 17β-estradiol (E2) in the sediments ranged from <1.3 to 10.9 ng/gdw and from <0.9 to 2.6 ng/gdw, respectively. The spatial distribution of these chemicals was related to the discharge of domestic and industrial wastewater along the rivers. The positive correlation between EDCs and total organic carbon indicates that sedimentary organic carbon is an important factor in controlling the distributions of EDCs. Compared with other previous studies, the ZR and DR rivers from the PRD were heavily contaminated by APs and BPA. PMID:21353256

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

    PubMed

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

    2016-04-01

    The concentration and chemical speciation of arsenic (As) in different environmental matrixes (water, sediment, agricultural soils, and non-agricultural soils) were investigated in the Nanpan River area, the upstream of Pearl River, China. The results did not show any obvious transport of As along the flow direction of the river (from upstream to downstream). Total As concentrations in sediment were significantly different from those in agricultural soil. According to the comparison to quality standards, the As in sediments of the studied area have potential ecological risks and a minority of the sampling sites of agricultural soils in the studied area were polluted with As. As speciations were analyzed using sequential extraction and the percentage of non-residual fraction in sediment predominated over residual fraction. We thus believe that As in the studied area was with low mobility and bioavailability in sediment, agricultural soils, and non-agricultural soils. However, the bioavailability and mobility of As in sediment were higher than in both agricultural and non-agricultural soils, and thus, special attention should be paid for the risk assessment of As in the river in future studies. PMID:26627697

  12. Water utilization in the White River Basin

    USGS Publications Warehouse

    Helland, R.O.

    1946-01-01

    This report presents briefly the results of an investigation of the water and power resources of the White river made in 1943 primarily for the purpose of classification of lands adjacent to the stream that have been withdrawn for power purposes. About three days were spent by the writer in field examination of the river basin during August and September. A survey of the river from its confluence with the Deschutes River to the Mt. Hood Loop Highway is published by the Survey. Nearly all of this map was surveyed in 1932. The entire basin is shown on quadrangle sheets. A record of discharge is available for the period 1917-43 at a station near the mouth of the river, and several short records are available at points upstream and on tributary streams.

  13. South Fork Holston River basin 1988 biomonitoring

    SciTech Connect

    Saylor, C.F.; Ahlstedt, S.A.

    1990-06-01

    There is concern over the effects of shifts in land use use practices on the aquatic fauna of streams in the South Fork Holston River basin in northwestern North Carolina and southwestern Virginia. Trout reproduction has noticeably declined in the Watauga River subbasin. The Watauga River and Elk River subbasins have been subjected to commercial and resort development. The Middle fork Holston River and the upper South Fork Holston River subbasins have been affected by agricultural and mining activities, respectively (Cox, 1986). To aid reclamation and management of the South Fork Holston basin, Tennessee Valley Authority (TVA) biologists conducted biomonitoring--including index of biotic integrity and macroinvertebrate sampling--on the Middle Fork Holston, South Fork Holston, Watauga, and Elk Rivers to assess cumulative impairment related to changes in habitat and pollutant loading in these subbasins. Biomonitoring can detect environmental degradation, help document problem areas, and assist in development of strategies for managing water quality. This report discusses the methods and materials and results of the biomonitoring of South Fork Holston River Basin. 13 refs., 5 figs., 12 tabs.

  14. Hotspots within the Transboundary Selenga River Basin

    NASA Astrophysics Data System (ADS)

    Kasimov, Nikolay; Lychagin, Mikhail; Chalov, Sergey

    2013-04-01

    Gathering the efficient information on water pollution of transboundary river systems remains the crucial task in international water management, environmental pollution control and prevention health problems. Countries, located in the low parts of the river basins, depend on the water strategy and water use in the adjacent countries, located upstream. Surface water pollution is considered to be the most serious problem, facing the above-mentioned countries. Large efforts in terms of field measurement campaigns and (numerical) transport modeling are then typically needed for relevant pollution prediction and prevention. Russian rivers take inflow from 8 neighboring countries. Among them there are 2 developing economies - People Republic of China and Mongolia, which are located in water-scarce areas and thus solve their water-related problems through the consumption of international water. Negative change of water runoff and water quality in the foreign part of transboundary river is appeared inside Russian territory with more or less delay. The transboundary river system of Selenga is particularly challenging, being the biggest tributary of Lake Baikal which is the largest freshwater reservoir in the world. Selenga River contributes about 50 % of the total inflow into Baikal. It originates in the mountainous part of Mongolia and then drains into Russia. There are numerous industries and agricultural activities within the Selenga drainage basin that affect the water quality of the river system. Absence of the single monitoring system and predictive tools for pollutants transport in river system requires large efforts in understanding sources of water pollution and implemented data on the relevant numerical systems for the pollution prediction and prevention. Special investigations in the Selenga river basin (Mongolia and Russia) were done to assess hot spots and understand state-of-the art in sediment load, water chemistry and hydrobiology of transboundary systems

  15. [Spatial and temporal distribution of organochlorine pesticides (OCPs) in surface water from the Pearl River Artery estuary].

    PubMed

    Yang, Qing-shu; Mai, Bi-xian; Fu, Jia-mo; Sheng, Guo-ying; Wang, Jing-xin

    2004-03-01

    Six water samples were collected, and twenty-one compounds of organochlorine pesticides (OCPs) in surface water from the Pearl River Artery estuary were analyzed quantitatively, based on USEPA 8000 series methods and under quality assurance and quality control (QA/QC). The total (particulate plus dissolved phase) concentration of OCPs in surface water from the Pearl River Artery estuary in both high flow season and low flow season were 9.7 ng/L-26.3 ng/L and 41.7 ng/L-122.5 ng/L respectively. The concentration of total HCHs and total other OCPs was much higher than that of DDTs. The seasonality of the concentration of OCPs was significantly, and the level of OCPs in low flow season was higher than that of OCPs in high flow season. The spatial and temporal distribution of OCPs suggested that there were significant differences of OCPs between the East River (Dongjiang) network and Guangzhou channel and the nonpoint-source pollution of OCPs was found in the Pearl River Artery estuary, particularly in high flow season. PMID:15202254

  16. Modified Streamflows 1990 Level of Irrigation : Missouri, Colorado, Peace and Slave River Basin, 1928-1989.

    SciTech Connect

    A.G. Crook Company; United States. Bonneville Power Administration

    1993-07-01

    This report presents data for monthly mean streamflows adjusted for storage change, evaporation, and irrigation, for the years 1928-1990, for the Colorado River Basin, the Missouri River Basin, the Peace River Basin, and the Slave River Basin.

  17. 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

  18. Picoplankton and virioplankton abundance and community structure in Pearl River Estuary and Daya Bay, South China.

    PubMed

    Ni, Zhixin; Huang, Xiaoping; Zhang, Xia

    2015-06-01

    By using flow cytometry techniques, we investigated the abundance and composition of the heterotrophic prokaryotes, virioplankton and picophytoplankton community in the Pearl River Estuary and Daya Bay in the summer of 2012. We identified two subgroups of prokaryotes, high nucleic acid (HNA) and low nucleic acid (LNA), characterized by different nucleic acid contents. HNA abundance was significantly correlated with larger phytoplankton and Synechococcus (Syn) abundance, which suggested the important role of organic substrates released from primary producers on bacterial growth. Although LNA did not show any association with environmental variables, it was a vital component of the microbial community. In contrast to previous studies, the total virioplankton concentration had a poor relationship with nutrient availability. The positive relationship between large-sized phytoplankton abundance and the V-I population confirmed that V-I was a phytoplankton-infecting viral subgroup. Although the V-II group (bacteriophages) was dominant in the virioplankton community, it was not related with prokaryotic abundance, which indicated factors other than hosts controlling V-II abundance or the uncertainty of virus-host coupling. With respect to the picophytoplankton community, our results implied that river input exerted a strong limitation to Syn distribution in the estuary, while picoeukaryotes (Euk) were numerically less abundant and showed a quite different distribution pattern from that of Syn, and hence presented ecological properties distinct from Syn in our two studied areas. PMID:26040741

  19. RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

    SciTech Connect

    Robert Caldwell

    1998-04-01

    Vast quantities of natural gas are entrapped within various tight formations in the Rocky Mountain area. This report seeks to quantify what proportion of that resource can be considered recoverable under today's technological and economic conditions and discusses factors controlling recovery. The ultimate goal of this project is to encourage development of tight gas reserves by industry through reducing the technical and economic risks of locating, drilling and completing commercial tight gas wells. This report is the fourth in a series and focuses on the Wind River Basin located in west central Wyoming. The first three reports presented analyses of the tight gas reserves and resources in the Greater Green River Basin (Scotia, 1993), Piceance Basin (Scotia, 1995) and the Uinta Basin (Scotia, 1995). Since each report is a stand-alone document, duplication of language will exist where common aspects are discussed. This study, and the previous three, describe basin-centered gas deposits (Masters, 1979) which contain vast quantities of natural gas entrapped in low permeability (tight), overpressured sandstones occupying a central basin location. Such deposits are generally continuous and are not conventionally trapped by a structural or stratigraphic seal. Rather, the tight character of the reservoirs prevents rapid migration of the gas, and where rates of gas generation exceed rates of escape, an overpressured basin-centered gas deposit results (Spencer, 1987). Since the temperature is a primary controlling factor for the onset and rate of gas generation, these deposits exist in the deeper, central parts of a basin where temperatures generally exceed 200 F and drill depths exceed 8,000 feet. The abbreviation OPT (overpressured tight) is used when referring to sandstone reservoirs that comprise the basin-centered gas deposit. Because the gas resources trapped in this setting are so large, they represent an important source of future gas supply, prompting studies to

  20. The "normal" elongation of river basins

    NASA Astrophysics Data System (ADS)

    Castelltort, Sebastien

    2013-04-01

    The spacing between major transverse rivers at the front of Earth's linear mountain belts consistently scales with about half of the mountain half-width [1], despite strong differences in climate and rock uplift rates. Like other empirical measures describing drainage network geometry this result seems to indicate that the form of river basins, among other properties of landscapes, is invariant. Paradoxically, in many current landscape evolution models, the patterns of drainage network organization, as seen for example in drainage density and channel spacing, seem to depend on both climate [2-4] and tectonics [5]. Hovius' observation [1] is one of several unexplained "laws" in geomorphology that still sheds mystery on how water, and rivers in particular, shape the Earth's landscapes. This narrow range of drainage network shapes found in the Earth's orogens is classicaly regarded as an optimal catchment geometry that embodies a "most probable state" in the uplift-erosion system of a linear mountain belt. River basins currently having an aspect away from this geometry are usually considered unstable and expected to re-equilibrate over geological time-scales. Here I show that the Length/Width~2 aspect ratio of drainage basins in linear mountain belts is the natural expectation of sampling a uniform or normal distribution of basin shapes, and bears no information on the geomorphic processes responsible for landscape development. This finding also applies to Hack's [6] law of river basins areas and lengths, a close parent of Hovius' law. [1]Hovius, N. Basin Res. 8, 29-44 (1996) [2]Simpson, G. & Schlunegger, F. J. Geophys. Res. 108, 2300 (2003) [3]Tucker, G. & Bras, R. Water Resour. Res. 34, 2751-2764 (1998) [4]Tucker, G. & Slingerland, R. Water Resour. Res. 33, 2031-2047 (1997) [5]Tucker, G. E. & Whipple, K. X. J. Geophys. Res. 107, 1-1 (2002) [6]Hack, J. US Geol. Surv. Prof. Pap. 294-B (1957)

  1. 76 FR 61382 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. ] SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub....

  2. 75 FR 25877 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control ] Act of 1974...

  3. 75 FR 27360 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub....

  4. 77 FR 23508 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub....

  5. 75 FR 66389 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub....

  6. 76 FR 24515 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of... Committee Act, the Bureau of Reclamation announces that the Colorado River Basin Salinity Control Advisory...) 524-3826; e-mail at: kjacobson@usbr.gov . SUPPLEMENTARY INFORMATION: The Colorado River Basin...

  7. 78 FR 23784 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974...

  8. 78 FR 70574 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub....

  9. 77 FR 61784 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-11

    ... Bureau of Reclamation Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub....

  10. The Perennial Blooming of MGII and Their Correlation with MGI in the Pearl River Estuary, China

    NASA Astrophysics Data System (ADS)

    Xie, W.

    2015-12-01

    Marine Group (MG) I and MG II Archaea were first reported over two decades ago. While significant progress has been made on MG I, the progress on MG II has been noticeable slower. The common understanding is that while MG I mainly function as chemolithoautotrophs growing on ammonia and live predominantly in deeper water, MG II live heterotrophically and reside mostly in the photic zone. While some MG I lineages that could conduct ammonium oxidation are frequently found in terrestrial environments, MG II are exclusively found in marine environments and thus named Thalassoarchaea. A few studies showed MG IIs were sporadically blooming in coastal waters and may be influenced by the level of eutrophication between seasons, which inhibited the enrichment and cultivation for MGII. In this study, we quantified the abundance of planktonic MGI (represented by archaeal amoA gene) and MGII (16S rRNA gene) using qPCR in the water column of different salinities (A: 0.8‰; B: 18.1‰; C: 23.9‰: D: 31‰) in the Pearl River Estuary over a 12-month period. The results showed that the abundance of MGII in site C (8.5±10.1×107 copies/L) was significantly higher than the other three sites (A: 3.5±8.8×105 copies/L; B: 2.7±4.5×107 copies/L; D: 2.2±4.4×107 copies/L) in all seasons, indicating the perennial blooming of MGII that might be due to the optimal combination of available organic carbon and salinity at this site. We also observed that the correlation between MGI and MGII became better toward the marine water and was significant at site D (R2: A, 0.06; B, 0.1; C, 0.24; D, 0.64), indicating the potential functional relationship between them with increasing salinity. This allowed us to hypothesize that the growth of MGI in the coastal site is more dependent on release of ammonia from organic matter degradation by MGII and other heterotrophic organisms. The Pearl River estuary may be an ideal environment for testing this hypothesis, which may provide insight into the

  11. OHIO RIVER BASIN ENERGY STUDY: HEALTH ASPECTS

    EPA Science Inventory

    This report was prepared as part of the Ohio River Basin Energy Study (ORBES), a multi-disciplinary program supported by the Environmental Protection Agency. It attempts to establish health damage functions for energy resource extraction, conversion (i.e., burning of coal to prod...

  12. Central Mississippi River Basin LTAR site overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Central Mississippi River Basin (CMRB) member of the Long-Term Agro-ecosystem Research (LTAR) network is representative of the southern Corn Belt, where subsoil clay content makes tile drainage challenging and make surface runoff and associated erosion problematic. Substantial research infrastru...

  13. Nutrient levels in the Yazoo River Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High nitrogen (N) and phosphorus (P) loadings to aquatic ecosystems are linked to environmental problems including harmful algal blooms and hypoxia. Presented is an assessment of accessible data on nutrient sources, sinks and inputs to streams within the Yazoo River Basin of northern Mississippi. Ac...

  14. Production of Branched Tetraether Lipids in the Lower Pearl River and Estuary: Effects of Extraction Methods and Impact on bGDGT Proxies

    PubMed Central

    Zhang, Chuanlun L.; Wang, Jinxiang; Wei, Yuli; Zhu, Chun; Huang, Liuqin; Dong, Hailiang

    2012-01-01

    Branched glycerol dibiphytanyl glycerol tetraethers (bGDGTs) are known as bacterial lipids that occur widely in terrestrial environments, particularly in anaerobic peat bogs and soil. We examined the abundance and distribution of bGDGTs in both core (C) and polar (P) lipid fractions from the water column and surface sediments in the lower Pearl River (PR) and its estuary using two extraction methods (sonication vs. Bligh and Dyer). A number of soil samples in the lower PR drainage basin were also collected and extracted for bGDGTs using the sonication method. The results showed aquatic production of bGDGTs as supported by substantial abundances of P-bGDGTs in the water column and sediment samples. The bGDGT-based proxies (BIT, CBT, and MBT) were not affected by the method of extraction when C-bGDGTs were analyzed; in such case, the pHCBT of the sediments reflected the soil pH of the lower PR drainage basin, and the temperature close to the annual mean air temperature (MAT) in the lower PR basin. On the other hand, the P-bGDGT-derived proxies were inconsistent between the two methods. The P-bGDGTs (particularly those extracted using the sonication method) may not be reliable indicators of annual MATs. PMID:22291686

  15. Hydrological Modelling of Ganga River basin.

    NASA Astrophysics Data System (ADS)

    Anand, J.; Gosain, A. K.; Khosa, R.

    2015-12-01

    Application of a hydrological model, Soil and Water Assessment Tool (SWAT) to the Ganga basin having a total drainage area of around 1.08 M sq. km extending over Tibet, Nepal, India and Bangladesh has been made. The model is calibrated to determine the spatial deviations in runoff at sub-basin level, and to capture the water balance of the river basin. Manual calibration approach was used for calibrating the SWAT model by following multi-step procedure to get to the realistic present situation as close as possible. Simulations were then further made with and without proposed future projects to obtain various scenarios. The various statistical parameters used for the evaluation of the monthly runoff simulation showed that SWAT performed well in mimicking the monthly stream flow for Ganga River basin. The model under predicted the flows in the non-perennial region during non-monsoon season, due to low rainfall and regulated flows and seepage taking place from the reservoirs. The impacts of the interventions, both existing as well as proposed, on the water balance of the basin were evaluated and quantified. The derived results suggest that there is a substantial reduction in overall water resources availability in the study basin on account of the current level of development and further, future developments, as are being proposed, may require a careful study of their potential impact on currently sanctioned water use. The present study showcases that efficacy of the model for simulating the stream flow is admirable.

  16. Sediment fluxes in transboundary Selenga river basin

    NASA Astrophysics Data System (ADS)

    Belozerova, Ekaterina

    2013-04-01

    Gathering reliable information on transboundary river systems remains a crucial task for international water management and environmental pollution control. Countries located in the lower parts of the river basins depend on water use and management strategies in adjacent upstream countries. One important issue in this context is sediment transport and associated contaminant fluxes across the state borders. The mass flows of dissolved ions, biogens, heavy metal concentrations, as far as suspended sediment concentration (SSC, mg/l) along upper Selenga river and its tributaries based on the literature review and results of field campaigns 2011-2012 were estimated. Based on the water discharges measurements Q, suspended load WR (t/day) and dissolved loads WL were calculated. In the Selenga basin the minimal WR (1,34-3,74 t/day) were found at small rivers. Maximal sediment loads (WR = 15 000 t/day) were found at the upper Orkhon river during flood event. The downstream point (Mongolia-Russia border) was characterized 2 220 t/day in 2011. Generally the prevalence of the accumulation is found through calculating sediment budget for all rivers (ΔW = WR (downstream) - WR (upstream) < 0). Downstream of Orkhon river (below confluence with Tuul) ΔW = - 1145 t/day. Below Selenga-Orkhon confluence sediment yield reached 2515 t/day, which is corresponded to transboundary sediment flux. Silt sediments (0,001 - 0,05 mm) form the main portion of the transported material. The maximal value of sand flux (302 t/day) was reported for middle stream station of Selenga river (upstream from confluence with Orkhon). The increase of human activities (mining and pastures) increases the portion of clay particles in total sediment load (e.g. at the downstream point of most polluted Orkhon river it reached 207,8 t/day). The existed estimates are compared with distribution of the main matter sources within basin: mining and industry, river-bank erosion and slope wash. The heaviest increase of

  17. Seasonal variation of the land-sea breeze circulation in the Pearl River Delta region

    NASA Astrophysics Data System (ADS)

    Lu, Xi; Chow, Kim-Chiu; Yao, Teng; Fung, Jimmy C. H.; Lau, Alexis K. H.

    2009-09-01

    The data of a 1-year (2003-2004) simulation with a finest horizontal resolution of 1.5 km, using the Fifth-Generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5), were analyzed to investigate the seasonal-mean features of the land-sea breeze (LSB) and regional circulation over the Pearl River Delta (PRD) region in southern China. The seasonal-mean diurnal variations reveal the general patterns of the LSB in the four seasons. These small-scale mean flow fields in the region have not been revealed in any previous studies. The results reveal a strong anomalous westerly sea breeze toward the eastern coast of the PRD in the early afternoon that is present in all the four seasons but is particularly strong in autumn and winter and may enhance the low-level convergence in Hong Kong. Furthermore, the condition of the atmosphere in autumn and winter is much more stable when compared with that in spring and summer, which is not favorable for the vertical dispersion of pollutants. The overall effect of these mean meteorological conditions may be an important factor for the generally higher air pollution index observed in Hong Kong during autumn and winter.

  18. InSAR reveals coastal subsidence in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Wang, Hua; Wright, Tim J.; Yu, Yongping; Lin, Hong; Jiang, Lilong; Li, Changhui; Qiu, Guangxin

    2012-12-01

    The Pearl River Delta (PRD) is one of the most important economic regions with the highest population densities in China. With its dramatic increasing population and economy, hazards associated with land subsidence frequently occur here that amplify the negative effect of sea level rise. However, land subsidence has not been regularly measured in this region. Here, we use interferometric synthetic aperture radar (InSAR) to investigate the rate and extent of land subsidence in the PRD region. Assuming purely vertical displacements, multi-track interferograms from different viewing geometries are combined to estimate the linear rate map and time series at a higher resolution in time than is possible with a single track. The results show apparent subsidence along the coastal region of Shenzhen associated with rapid urban development in recent years. The average subsidence rate within 500 m of the coast is about 2.5 mm yr-1, and the maximum is up to about 6 mm yr-1 with respect to the central part of the city. Much of the land surface in the PRD is less than 2 m above mean sea level; high-precision geodetic measurements throughout the PRD region are therefore critical for conducting risk assessments, considering the rate of about 2-3 mm yr-1 of current global sea level rise.

  19. Container cargo simulation modeling for measuring impacts of infrastructure investment projects in Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Li, Jia-Qi; Shibasaki, Ryuichi; Li, Bo-Wei

    2010-03-01

    In the Pearl River Delta (PRD), there is severe competition between container ports, particularly those in Hong Kong, Shenzhen, and Guangzhou, for collecting international maritime container cargo. In addition, the second phase of the Nansha terminal in Guangzhou’s port and the first phase of the Da Chang Bay container terminal in Shenzhen opened last year. Under these circumstances, there is an increasing need to quantitatively measure the impact these infrastructure investments have on regional cargo flows. The analysis should include the effects of container terminal construction, berth deepening, and access road construction. The authors have been developing a model for international cargo simulation (MICS) which can simulate the movement of cargo. The volume of origin-destination (OD) container cargo in the East Asian region was used as an input, in order to evaluate the effects of international freight transportation policies. This paper focuses on the PRD area and, by incorporating a more detailed network, evaluates the impact of several infrastructure investment projects on freight movement.

  20. Comparison of driving characteristics in cities of Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Hung, Wing-Tat; Tam, Ka-Man; Lee, Chi-Pang; Chan, Lo-Yin; Cheung, Chun-Shun

    The cities in Pearl River Delta (PRD), China are going to merge into a big economy in the coming years. Hong Kong, Macao and Zhuhai are the three leading cities in PRD. A Hong Kong-Zhuhai-Macao Bridge is being actively proposed to link up these three cities. It will result in the changes of driving characteristics and thus, vehicle emissions. To quantify the impacts of emissions, we adopted a three-step approach to analyze the driving characteristics in these three cities. The approach involved deriving 10 driving parameters; the speed acceleration probability matrices (SAPM) as well as the driving cycles which allowed easy visualization of the driving characteristics. Car chasing technique was employed to collect speed-time data in peak and non-peak periods on both weekdays and weekends. The experimental cars were equipped with infrared tachometer, Global Positioning System receiver and microwave speed sensor. Through comparisons, we found major differences in driving characteristics including magnitude as well as spread and time proportions of driving speeds. These differences were attributed by the road network layout, vehicle density and driving behaviour. Aggressive driving and low driving speeds in urban cities would generate higher vehicle emissions.

  1. Public health and medical care for the world's factory: China's Pearl River Delta Region

    PubMed Central

    2011-01-01

    While the growth of urbanization, worldwide, has improved the lives of migrants from the hinterland, it also raises health risks related to population density, concentrated poverty and the transmission of infectious disease. Will megacity regions evolve into socially infected breeding grounds for the rapid transmission of disease, or can they become critical spatial entities for the protection and promotion of population health? We address this question for the Pearl River Delta Region (PRD) based on recent data from Chinese sources, and on the experience of how New York, Greater London, Tokyo and Paris have grappled with the challenges of protecting population health and providing their populations with access to health care services. In some respects, there are some important lessons from comparative experience for PRD, notably the importance of covering the entire population for health care services and targeting special programs for those at highest risk for disease. In other respects, PRD's growth rate and sheer scale make it a unique megacity region that already faces new challenges and will require new solutions. PMID:21968214

  2. An ozone episode over the Pearl River Delta in October 2008

    NASA Astrophysics Data System (ADS)

    Shen, Jin; Zhang, Yuanhang; Wang, Xuesong; Li, Jinfeng; Chen, Hao; Liu, Run; Zhong, Liuju; Jiang, Ming; Yue, Dingli; Chen, Duohong; Lv, Wei

    2015-12-01

    The north and east Pearl River Delta (PRD) is usually a clean, upwind area in autumn. Serious ozone pollution there in mid-late October 2008 was first discovered and then analyzed. Trajectory analysis, process analysis, ozone source apportionment technology, and sensitivity analysis were used to study this episode. Under the influence of a weak south wind, the precursors emitted in Guangzhou and Foshan were transported to the north and northeast PRD and formed ozone there, which resulted in high ozone concentration (>100 ppb). As the wind direction later transited to northerly, the precursors in the northeast PRD that originated from the central and west PRD were transported to the south, and caused severe ozone pollution in the southeast PRD. The ozone contributed by chemical processes reached >20 ppb/h in Jinguowan. More than 40 ppb ozone was contributed by the precursor emission in the central and west PRD during the episode. The ozone concentration was highly sensitive to the precursor emission in the PRD region in the high-ozone situations. This episode showed the complexity of regional pollution in the PRD. When the PRD is controlled by a low air pressure system and then cold air moves from northern China to the south, the risk of ozone pollution in the north and southeast PRD increases.

  3. Delaying precipitation and lightning by air pollution over the Pearl River Delta. Part I: Observational analyses

    NASA Astrophysics Data System (ADS)

    Guo, Jianping; Deng, Minjun; Lee, Seoung Soo; Wang, Fu; Li, Zhanqing; Zhai, Panmao; Liu, Huan; Lv, Weitao; Yao, Wen; Li, Xiaowen

    2016-06-01

    The radiative and microphysical effects of aerosols can affect the development of convective clouds. The objective of this study is to reveal if the overall aerosol effects have any discernible impact on the diurnal variations in precipitation and lightning by means of both observational analysis and modeling. As the first part of two companion studies, this paper is concerned with analyzing hourly PM10, precipitation, and lightning data collected during the summers of 2008-2012 in the Pearl River Delta region. Daily PM10 data were categorized as clean, medium, or polluted so that any differences in the diurnal variations in precipitation and lightning could be examined. Heavy precipitation and lightning were found to occur more frequently later in the day under polluted conditions than under clean conditions. Analyses of the diurnal variations in several meteorological factors such as air temperature, vertical velocity, and wind speed were also performed. They suggest that the influence of aerosol radiative and microphysical effects serve to suppress and enhance convective activities, respectively. Under heavy pollution conditions, the reduction in solar radiation reaching the surface delays the occurrence of strong convection and postpones heavy precipitation to late in the day when the aerosol invigoration effect more likely comes into play. Although the effect of aerosol particles can be discernible on the heavy precipitation through the daytime, the influence of concurrent atmospheric dynamics and thermodynamics cannot be ruled out.

  4. Tidal Flux Variation in the Lower Pearl River and Lake Pontchartrain Estuaries of Mississippi and Louisiana

    USGS Publications Warehouse

    Turnipseed, D.P.

    2002-01-01

    Three tidal gages were constructed to collect hydraulic and water-quality properties that could be used to compute the tidal flux of the Pearl River and Lake Pontchartrain estuarine systems in Mississippi and Louisiana. The gages record continuous tidal stage, velocity, water temperature, specific conductance, and salinity, and transmit these data via the GOES satellite for output to a USGS real-time Internet portal. A 25-hour tidal study was completed during a maximum slack tide period in September 2001, which measured hydraulic and water-quality properties. These data were correlated with data recorded by the gages. Relations were developed for stage and area, and for an index acoustic velocity signal and average velocity. Continuous tidal inflow/outflow was computed for all three gages. Tidal effects were attenuated using a ninth-order Butterworth low-pass filter. Net inflows were recorded at two of three sites during the tidal study. The data will be used to help calibrate a regional RMA2 flow model.

  5. Grid based model computation of virtual geographic environment: application in Pearl River Delta air pollution visualization

    NASA Astrophysics Data System (ADS)

    Xu, Bingli; Lin, Hui; Zhu, Jun; Tang, Sammy; Lin, Wenshi; Wu, Jianbin

    2008-10-01

    Virtual Geographic Environment (VGE) is a virtual representation of the physical world, culture world and imaginary world. Compared with GIS, VGE has two core components, which are Data and Model respectively. Many models in VGE are complex and therefore the model calculations for them are very time consuming as well. How to decrease and reduce the required model computation time to improve VGE efficiency will be a vital and key issue for most of the VGE implementation. In this research, we adopt CUGrid as the model computation server, which contains more than two hundred CPUs for fast and intensive computation. With the CUGrid, MM5 based air pollution data in Pearl River Delta is used as the test case for this study. According to the test results, we managed to reduce the required model computation time from the original three months on one specific desktop to several minutes on the CUGrid. Another significance and benefit of this research is that we also able to integrate MM5 with geographic information, which makes concepts on air pollution can easily be understood by the public.

  6. Humpback Dolphins in Hong Kong and the Pearl River Delta: Status, Threats and Conservation Challenges.

    PubMed

    Karczmarski, Leszek; Huang, Shiang-Lin; Or, Carmen K M; Gui, Duan; Chan, Stephen C Y; Lin, Wenzhi; Porter, Lindsay; Wong, Wai-Ho; Zheng, Ruiqiang; Ho, Yuen-Wa; Chui, Scott Y S; Tiongson, Angelico Jose C; Mo, Yaqian; Chang, Wei-Lun; Kwok, John H W; Tang, Ricky W K; Lee, Andy T L; Yiu, Sze-Wing; Keith, Mark; Gailey, Glenn; Wu, Yuping

    2016-01-01

    In coastal waters of the Pearl River Delta (PRD) region, the Indo-Pacific humpback dolphin (Sousa chinensis) is thought to number approximately 2500 individuals. Given these figures, the putative PRD population may appear strong enough to resist demographic stochasticity and environmental pressures. However, living in close proximity to the world's busiest seaport/airport and several densely populated urban centres with major coastal infrastructural developments comes with challenges to the long-term survival of these animals. There are few other small cetacean populations that face the range and intensity of human-induced pressures as those present in the PRD and current protection measures are severely inadequate. Recent mark-recapture analyses of the animals in Hong Kong waters indicate that in the past two decades the population parameters have not been well understood, and spatial analyses show that only a very small proportion of the dolphins' key habitats are given any form of protection. All current marine protected areas within the PRD fail to meet a minimum habitat requirement that could facilitate the population's long-term persistence. Demographic models indicate a continuous decline of 2.5% per annum, a rate at which the population is likely to drop below the demographic threshold within two generations and lose 74% of the current numbers within the lifespan of three generations. In Hong Kong, the case of humpback dolphins represents a particularly explicit example of inadequate management where a complete revision of the fundamental approach to conservation management is urgently needed. PMID:26790887

  7. 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

  8. 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

  9. Public health and medical care for the world's factory: China's Pearl River Delta Region.

    PubMed

    Fabre, Guilhem; Rodwin, Victor G

    2011-01-01

    While the growth of urbanization, worldwide, has improved the lives of migrants from the hinterland, it also raises health risks related to population density, concentrated poverty and the transmission of infectious disease. Will megacity regions evolve into socially infected breeding grounds for the rapid transmission of disease, or can they become critical spatial entities for the protection and promotion of population health? We address this question for the Pearl River Delta Region (PRD) based on recent data from Chinese sources, and on the experience of how New York, Greater London, Tokyo and Paris have grappled with the challenges of protecting population health and providing their populations with access to health care services. In some respects, there are some important lessons from comparative experience for PRD, notably the importance of covering the entire population for health care services and targeting special programs for those at highest risk for disease. In other respects, PRD's growth rate and sheer scale make it a unique megacity region that already faces new challenges and will require new solutions. PMID:21968214

  10. Yazoo River Basin (Lower Mississippi River) Hydrologic Observatory

    NASA Astrophysics Data System (ADS)

    Cheng, A.; Davidson, G.; Altinakar, M.; Holt, R.

    2004-12-01

    The proposed Yazoo River Basin Hydrologic Observatory consists of the 34,000 square km Yazoo River watershed in northwestern Mississippi and a 320 km segment of the Mississippi River separated from the watershed by a manmade levee. Discharge from the basin flows from the Yazoo River into the Mississippi River north of Vicksburg, MS. Major streams within the basin include the Yazoo, Tallahatchie, Yalobusha, Coldwater, Yocona, and Big Sunflower Rivers. Four large flood control reservoirs (Arkabutla, Enid, Sardis, and Grenada) and two national forests (Delta and Holly Springs) are also located within the basin. The watershed is divided between upland forested hills and intensively cultivated lowlands. The lowland area, locally known as the "Delta", lies on the ancestral floodplain of the Mississippi River. Flooding by the Mississippi River was once a common event, but is now limited by the levee system. Abundant wetlands occupy abandoned stream channels throughout the Delta. The Yazoo River Basin has many unique features that make it an attractive site for an Hydrologic Observatory. Example features and issues of scientific interest include: 1) Extensive system of levees which have altered recharge to the regional aquifer, shifted population centers, and created backwater flooding areas. 2) Abundant wetlands with a century-long history of response to agricultural sediment and chemical fluxes. 3) Erosion of upland streams, and stream sediment loads that are the highest in the nation. 4) Groundwater mining in spite of abundant precipitation due to a regional surface clay layer that limits infiltration. 5) A history of agricultural Best Management Practices enabling evaluation of the effectiveness of such measures. 6) Large scale catfish farming with heavy reliance on groundwater. 7) Near enough to the Gulf coast to be impacted by hurricane events. 8) Already existing network of monitoring stations for stream flow, sediment-load, and weather, including complete coverage

  11. Precipitation and temperature changes in the major Chinese river basins during 1957-2013 and links to sea surface temperature

    NASA Astrophysics Data System (ADS)

    Tian, Qing; Prange, Matthias; Merkel, Ute

    2016-05-01

    The variation characteristics of precipitation and temperature in the three major Chinese river basins (Yellow River, Yangtze River and Pearl River) in the period of 1957-2013 were analyzed on an annual and seasonal basis, as well as their links to sea surface temperature (SST) variations in the tropical Pacific and Indian Ocean on both interannual and decadal time scales. Annual mean temperature of the three river basins increased significantly overall since 1957, with an average warming rate of about 0.19 °C/10a, but the warming was characterized by a staircase form with steps around 1987 and 1998. The significant increase of annual mean temperature could mostly be attributed to the remarkable warming trend in spring, autumn and winter. Warming rates in the northern basins were generally much higher than in the southern basins. However, both the annual precipitation and seasonal mean precipitation of the three river basins showed little change in the study area average, but distinct interannual variations since 1957 and clear regional differences. An overall warming-wetting tendency was found in the northwestern and southeastern river basins in 1957-2013, while the central regions tended to become warmer and drier. Results from a Maximum Covariance Analysis (MCA) showed that the interannual variations of seasonal mean precipitation and surface air temperature over the three river basins were both associated with the El Niño-Southern Oscillation (ENSO) since 1957. ENSO SST patterns affected precipitation and surface air temperature variability throughout the year, but with very different response patterns in the different seasons. For instance, temperature in most of the river basins was positively correlated with central-eastern equatorial Pacific SST in winter and spring, but negatively correlated in summer and autumn. On the decadal time scale, the seasonal mean precipitation and surface air temperature variations were strongly associated with the Pacific

  12. Isotopic evidence for the turnover of biological reactive nitrogen in the Pearl River Estuary, south China

    NASA Astrophysics Data System (ADS)

    Ye, Feng; Ni, Zhixin; Xie, Luhua; Wei, Gangjian; Jia, Guodong

    2015-04-01

    Nitrate (NO3-) concentrations and the isotopic composition (δ15N and δ18O) of water samples from the Pearl River Estuary (PRE), south China, were measured to constrain N sources and processing in springtime. Nitrate concentrations decreased at higher salinities, and dual isotopic values were correlated with 1/[NO3-], both of which suggest mixing of eutrophic freshwater and oligotrophic seawater. However, δ15N and δ18O values did not closely follow the expected mixing lines. At low salinities (0-3.0), some samples exhibited high δ15N and low δ18O values compared with those of the riverine end-member, indicating that sewage is a significant source of nitrate (up to 19.0% calculated from δ15N). At salinities of >3.0, Δδ15N and Δδ18O values are linearly correlated with lnƒ (the fraction of NO3- remaining in the system), which is attributable to isotopic Rayleigh fractionation during phytoplankton uptake of nitrate. However, the linear relationship between Δδ15N and Δδ18O is different between the west and east PRE, with a slope of 1.18 in the west and 1.59 in the east. This difference most likely resulted from varying degrees of nitrification due to different water velocities and residence times in the two areas. Our data therefore indicate that dual nitrate isotopic signatures are a valuable way to constrain the sources and behavior of nitrate in river-dominated estuaries.

  13. Organochlorine pesticides in the surface water and sediments of the Pearl River Estuary, South China.

    PubMed

    Yu, Mei; Luo, Xiaojun; Chen, Shejun; Mai, Bixian; Zeng, Eddy Y

    2008-01-01

    Samples of surface water, suspended particulate matter (SPM), and surface sediment, collected from the Pear River Estuary, Guangdong Province, China in July of 2002 and April of 2003, were analyzed for hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) using gas chromatography with electron capture detection. The levels of total HCHs in water varied from 213 to 3,116 pg/L, although in sediments they ranged from 181 to 1,388 pg/g dry weight. The levels of DDTs were in the range of 228 to 3,284 pg/L in water and 57 to 2,244 pg/g dry weight in sediments, respectively. The observed spatial and temporal variability of concentrations of the target compounds in water body could be attributed to the differences of SPM contents in water body and organic carbon contents in SPM between the two sampling periods. Seven of the 10 water samples collected in July of 2002 had the ratio of dichlorodiphenyltrichloroethane/(dichlorobischlorophenylethane + dichlorodiphenyldichloroethylene) (DDT/[DDD + DDE]) higher than one, indicating that there were likely fresh inputs of DDT to the Pearl River Estuary. The significant positive correlations between the organochlorine pesticide concentrations and organic carbon contents in SPM and sediments indicated that organic matter played an important role in controlling the distributions of these pollutants in the marine environment. Varied correlations between the partition coefficients of pollutants and total organic carbon, salinity, and total SPM contents have been observed, which indicated the influences of these factors on controlling the transport and fate of pollutants in the marine environment. PMID:18092858

  14. Flood tracking chart, Amite River basin, Louisiana

    USGS Publications Warehouse

    Callender, Lawrence; McCallum, Brian E.; Brazelton, Sebastian R.

    1996-01-01

    The Amite River Basin flood tracking chart is designed to assist emergency response officials and the local public in making informed decisions about the safety of life and property during floods along the Amite and Comite Rivers and Bayou Manchac in southeastern Louisiana. This chart is similar in concept to the charts used to track hurricanes; the user can record the latest river stage information at selected gaging stations and the latest flood crest predictions. The latest stage data can be compared to historical flood peaks as well as to the slab or pier elevation of a threatened property. The chart also discusses how to acquire the latest river stage data from the Internet and a recorded voice message.

  15. Flood tracking chart, Amite River Basin, Louisiana

    USGS Publications Warehouse

    Callender, Lawrence E.; McCallum, Brian E.; Brazelton, Sebastian R.; Anderson, Mary L.; Ensminger, Paul A.

    1998-01-01

    The Amite River Basin flood tracking chart is designed to assist emergency response officials and the local public in making informed decisions about the safety of life and property during floods along the Amite and Comite Rivers and Bayou Manchac in southeastern Louisiana. This chart is similar in concept to the charts used to track hurricanes; the user can record the latest river stage information at selected gaging stations and the latest flood crest predictions. The latest stage data can be compared to historical flood peaks as well as to the slab or pier elevation of a threatened property. The chart also discusses how to acquire the latest river stage data from the Internet and a recorded voice message.

  16. 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. PMID:15952354

  17. Mississippi River, Yazoo Basin, Memphis, TN

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This section of the lower Mississippi River (34.0N, 90.0W) known as the Yazoo Basin, is characterized by a wide expanse of rich river bottomland with many oxbow lakes, the remains of the many changes in the riverbed over the course of many thousands of years. This soil is very fertile and productive but the region is prone to flooding. In this view, some of the back areas around the Delta National Forest show the effects of heavy spring rains.

  18. Compositional Dynamics of Organic Carbon in Surface Sediments from the Lower Pearl River to the Coastal South China Sea

    NASA Astrophysics Data System (ADS)

    Li, X.; Zhang, C.; Wade, T.

    2015-12-01

    As the second largest river in China, the Pearl River discharges ˜7×107 tons of sediment annually to the South China Sea (SCS). About 80% of the sediment was deposited within the Pearl River Estuary; however, the compositional dynamics of organic carbon (OC) at this land-ocean interface is poorly known. This study aimed to delineate the sources, effect of the dam construction and the fate of sedimentary OC from the Feilaixia Dam to the Pearl River estuary and coastal SCS. Surface sediment was collected during a cruise in January 2012 for elemental, and stable carbon/nitrogen isotope analyses. Preliminary data showed that total OC increased from 0.6% at the Feilaixia Dam to 3.1% at Sihui city (100 km downstream from the dam), with the C/N ratio increasing from 10.4 to 18.9; the δ13C of OC, on the other hand, decreased from -20.57‰ to -29.04‰. From Sihui city to the edge of the Pearl River estuary (202 km from the dam), total OC (1.2± 0.6), C/N ratio (11.5 ± 1.0) and the δ13C of OC (-25.89 ± 0.69 ‰) all remained relatively constant. From the estuary towards the coastal SCS, the total OC decreased from 1.3 to 0.4%, with the C/N ratio also decreasing from 10.5 to 7.5; the δ13C of OC, on the other hand, increased from -26.24 to -21.20‰. These data indicate that the composition of riverine OC in general reflects terrestrial vascular plants (higher C/N ratio and more negative δ13C), which can be compounded by in situ primary production (lower C/N ratio and more positive δ13C) in the dam-created reservoir water body. The riverine organic matter, however, appears to regain its terrestrial signature before entering the estuary, which then is in balance with marine primary production (lower C/N ratio and more positive δ13C). The impact of soil and aquatic microbial processes on organic matter degradation also will be examined by analyzing their signature biomarkers and relationship to OC composition.

  19. An ozone episode in the Pearl River Delta: Field observation and model simulation

    NASA Astrophysics Data System (ADS)

    Jiang, F.; Guo, H.; Wang, T. J.; Cheng, H. R.; Wang, X. M.; Simpson, I. J.; Ding, A. J.; Saunders, S. M.; Lam, S. H. M.; Blake, D. R.

    2010-11-01

    In the fall of 2007 concurrent air sampling field measurements were conducted for the first time in Guangzhou (at Wan Qing Sha (WQS)) and Hong Kong (at Tung Chung (TC)), two cities in the rapidly developing Pearl River Delta region of China that are only 62 km apart. This region is known to suffer from poor air quality, especially during the autumn and winter months, when the prevailing meteorological conditions bring an outflow of continental air to the region. An interesting multiday O3 pollution event (daily maximum O3 > 122 ppbv) was captured during 9-17 November at WQS, while only one O3 episode day (10 November) was observed at TC during this time. The mean O3 mixing ratios at TC and WQS during the episode were 38 ± 3 (mean ± 95% confidence interval) and 51 ± 7 ppbv, respectively, with a mean difference of 13 ppbv and a maximum hourly difference of 150 ppbv. We further divided this event into two periods: 9-11 November as Period 1 and 12-17 November as Period 2. The mixing ratios of O3 and its precursors (NOx and CO) showed significant differences between the two periods at TC. By contrast, no obvious difference was found at WQS, indicating that different air masses arrived at TC for the two periods, as opposed to similar air masses at WQS for both periods. The analysis of VOC ratios and their relationship with O3 revealed strong O3 production at WQS during Period 2, in contrast to relatively weak photochemical O3 formation at TC. The weather conditions implied regional transport of O3 pollution during Period 1 at both sites. Furthermore, a comprehensive air quality model system (Weather Research and Forecasting-Community Multiscale Air Quality model (WRF-CMAQ)) was used to simulate this O3 pollution event. The model system generally reproduced the variations of weather conditions, simulated well the continuous high O3 episode event at WQS, and captured fairly well the elevated O3 mixing ratios in Period 1 and low O3 levels in Period 2 at TC. The modeled

  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. Process analysis of regional aerosol pollution during spring in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Fan, Qi; Lan, Jing; Liu, Yiming; Wang, Xuemei; Chan, Pakwai; Hong, Yingying; Feng, Yerong; Liu, Yexin; Zeng, Yanjun; Liang, Guixiong

    2015-12-01

    A numerical simulation analysis was performed for three air pollution episodes in the Pearl River Delta (PRD) region during March 2012 using the third-generation air quality modeling system Models-3/CMAQ. The results demonstrated that particulate matter was the primary pollutant for all three pollution episodes and was accompanied by relatively low visibility in the first two episodes. Weather maps indicate that the first two episodes occurred under the influence of warm, wet southerly air flow systems that led to high humidity throughout the region. The liquid phase reaction of gaseous pollutants resulted in the generation of fine secondary particles, which were identified as the primary source of pollution in the first two episodes. The third pollution episode occurred during a warming period following a cold front. Relative humidity was lower during this episode, and coarse particles were the major pollution contributor. Results of process analysis indicated that emissions sources, horizontal transport and vertical transport were the primary factors affecting pollutant concentrations within the near-surface layer during all three episodes, while aerosol processes, cloud processes, horizontal transport and vertical transport had greater influence at approximately 900 m above ground. Cloud processes had a greater impact during the first two pollution episodes because of the higher relative humidity. In addition, by comparing pollution processes from different cities (Guangzhou and Zhongshan), the study revealed that the first two pollution episodes were the result of local emissions within the PRD region and transport between surrounding cities, while the third episode exhibited prominent regional pollution characteristics and was the result of regional pollutant transport.

  2. Emission patterns and spatiotemporal variations of halocarbons in the Pearl River Delta region, southern China

    NASA Astrophysics Data System (ADS)

    Zhang, Y. L.; Guo, H.; Wang, X. M.; Simpson, I. J.; Barletta, B.; Blake, D. R.; Meinardi, S.; Rowland, F. S.; Cheng, H. R.; Saunders, S. M.; Lam, S. H. M.

    2010-08-01

    On 8 selected days between 25 October and 1 December 2007, 198 whole air samples were simultaneously collected at two sites in the greater Pearl River Delta (PRD), namely, Wan Qing Sha (WQS) in inland PRD and Tung Chung (TC) in Hong Kong, for the evaluation of halocarbons including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and other chlorinated compounds. The mean mixing ratios of CFC-12, CH3CCl3, CH3Br, C2HCl3, and C2Cl4 at WQS were much higher than those at TC (p < 0.001), while HCFC-22 was higher at TC (p < 0.01). Long-lived species such as CFC-11, CFC-12, and CFC-113 showed similar temporal patterns on most sampling days with small daily variation, whereas the main species used as solvents such as C2HCl3 and C2Cl4 presented large daily variations though with consistent temporal patterns. Source profile analysis revealed that although there was no remarkable change in emission sources between 2001-2002 and 2007, the emissions of CFCs and CCl4 from the production of refrigeration in 2007 were 1.4-2.0 times those in 2001-2002, and the use of HCFC-22 has significantly increased in these years while the use of C2HCl3 and C2Cl4 in the electronics industry showed a remarkable reduction. By comparing the halocarbon data collected in this study with those observed by other research teams in recent years, we found that the levels of CFCs have declined since 2001, while their substitute HCFC-22 has increased in emissions in recent years, especially in Hong Kong. The annual trends are consistent with the implementation of the Montreal Protocol. The results obtained in this study provide useful information to local government on effective control of halocarbon emissions in this region.

  3. Characteristics of carbonaceous aerosol in PM 2.5: Pearl Delta River Region, China

    NASA Astrophysics Data System (ADS)

    Huang, H.; Ho, K. F.; Lee, S. C.; Tsang, P. K.; Ho, Steven Sai Hang; Zou, C. W.; Zou, S. C.; Cao, J. J.; Xu, H. M.

    2012-02-01

    Simultaneous measurements of atmospheric organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) were made at four sampling sites, namely Guangzhou (GZ), Zhaoqing (ZQ), PolyU Campus (PU) and Hok Tsui (HT), in the Pearl River Delta (PRD) region between 14 August 2006 and 28 August 2007. The highest concentrations of total carbon (TC) were found at the medium-scale roadside site (PU) and the lowest were found at the regional-scale site (HT). Among the four sampling sites, the average WSOC at ZQ showed the highest concentrations, while the lowest were seen at HT. OC and EC concentrations revealed spring/summer minima and autumn/winter maxima at all sites except PU, which had a consistently high EC concentration all over the year. The highest WSOC/OC ratio was found at ZQ with an average of 0.41, suggesting that the OC was more oxidized in the atmosphere of the semi-rural site. The lowest WSOC/OC was found at the roadside site of PU. Moreover, the WSOC/OC ratio increased in autumn, when the photochemical reactions are the most active in the PRD region. This can be attributed to aging and atmospheric processing of the organic compounds during their transportation, or to the formation of secondary organic aerosol (SOA). Average annual secondary organic carbon (SOC) concentrations in PM2.5 were estimated to be 2.2 and 3.5 μg m- 3 for GZ and ZQ, comprising 33.5% and 42.8% of the corresponding OC concentrations, respectively. The results indicate that SOC is significant in the PRD region, and its formation mostly occurs within the region.

  4. Observationally-constrained carbonaceous aerosol source estimates for the Pearl River Delta area of China

    NASA Astrophysics Data System (ADS)

    Li, N.; Fu, T.-M.; Cao, J. J.; Zheng, J. Y.; He, Q. Y.; Long, X.; Zhao, Z. Z.; Cao, N. Y.; Fu, J. S.; Lam, Y. F.

    2015-11-01

    We simulated elemental carbon (EC) and organic carbon (OC) aerosols over the Pearl River Delta (PRD) area of China and compared the results to seasonal surface measurements, with the aim of quantifying carbonaceous aerosol sources from a "top-down" perspective. Our regional model was driven by current-best estimates of PRD EC (39.5 Gg C yr-1) and OC (32.8 Gg C yr-1) emissions and included updated secondary organic aerosol formation pathways. The simulated annual mean EC and OC concentrations were 4.0 and 7.7 μg C m-3, respectively, lower than the observed annual mean EC and OC concentrations (4.5 and 13.1 μg C m-3, respectively). We used multiple regression to match the simulated EC against seasonal mean observations. The resulting top-down estimate for EC emission in the PRD area was 52.9 ± 8.0 Gg C yr-1. We estimated the OC emission in the PRD area to be 60.2 ± 10.3 Gg C yr-1, based on the top-down EC emission estimate and the primary OC / EC ratios derived from bottom-up statistics. Using these top-down emission estimates, the simulated average annual mean EC and OC concentrations were improved to 4.4 and 9.5 μg C m-3, respectively, closer to the observations. Secondary sources accounted for 42 % of annual mean surface OC in our top-down simulations, with biogenic VOCs being the most important precursors.

  5. [Abundance and biomass of meiobenthos in Lingdingyang Bay of Pearl River Estuary].

    PubMed

    Zhang, Jing-huai; Gao, Yang; Fang, Hong-da

    2011-10-01

    An investigation was conducted on the meiobenthic abundance and biomass in the Lingdingyang Bay of Pearl River Estuary in July-August 2006 (summer), April 2007 (spring), and October 2007 (autumn). A total of 15 meiobenthic groups were recorded, including Nematoda, Copepoda, Polychaeta, Ostracoda, Kinorhyncha, Amphipoda, Cumacea, Tanaidacea, Gnathostomulida, Nemertea, Gastropoda, Bivalvia, Sipuncula, Echiura, and other unidentified taxa. The average abundance of the meiobenthos in spring, summer, and autumn was 272.1 +/- 281.9, 165.1 +/- 147.1 and 246. 4 +/- 369.3 ind 10 cm(-2), and Nematoda was the most dominant group in abundance, accounting for 86.8%, 83.5%, and 93.4% of the total, respectively, followed by Polychaeta, and benthic Copepoda. The meiobenthic abundance had an uneven vertical distribution. 54.1% of the meibenthos were in 0-2 cm sediments, 35.2% were in 2-5 cm sediments, and 10.8% were in 5-10 cm sediments. 87.4% of nematodes were distributed in 0-5 cm sediments. The average biomass of the meiobenthos in spring, summer, and autumn was 374.6 +/- 346.9, 274.1 +/- 352.2, and 270.8 +/- 396.0 microg 10 cm(-2), and Polychaeta was the most dominant group in biomass, accounting for 30.1%, 46.7% and 46.0%, respectively, followed by Nematoda (25.2%, 20.1%, and 34.0%), and Ostracoda (20.6%, 15.3%, and 14.8%). The horizontal distribution of the meiobenthos had a trend of increasing from north to south, and being higher at east than at west. The meiobenthic abundance and biomass had significant positive correlations with water depth. PMID:22263483

  6. Arsenic contamination in the freshwater fish ponds of Pearl River Delta: bioaccumulation and health risk assessment.

    PubMed

    Cheng, Zhang; Chen, Kun-Ci; Li, Kai-Bin; Nie, Xiang-Ping; Wu, Sheng Chun; Wong, Chris Kong-Chu; Wong, Ming-Hung

    2013-07-01

    This study investigated the extent of arsenic (As) contamination in five common species of freshwater fish (northern snakehead [Channa argus], mandrarin fish [Siniperca chuatsi], largemouth bass [Lepomis macrochirous], bighead carp [Aristichthys nobilis] and grass carp [Ctenopharyngodon idellus]) and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The total As concentrations detected in fish muscle and sediment in freshwater ponds around the PRD were 0.05-3.01 mg kg(-1) wet weight (w. wt) and 8.41-22.76 mg kg(-1) dry weight (d. wt), respectively. In addition, the As content was positively correlated (p < 0.05) to total organic carbon (TOC) contents in sediments. Biota sediment accumulation factor (BSAF) showed that omnivorous fish and zooplankton accumulated higher concentrations of heavy metals from the sediment than carnivorous fish. In addition, feeding habits of fish also influence As accumulation in different fish species. In this study, two typical food chains of the aquaculture ponds were selected for investigation: (1) omnivorous food chain (zooplankton, grass carp and bighead carp) and (2) predatory food chain (zooplankton, mud carp and mandarin fish). Significant linear relationships were obtained between log As and δ (15)N. The slope of the regression (-0.066 and -0.078) of the log transformed As concentrations and δ (15)N values, as biomagnifications power, indicated there was no magnification or diminution of As from lower trophic levels (zooplankton) to fish in the aquaculture ponds. Consumption of largemouth bass, northern snakehead and bighead carp might impose health risks of Hong Kong residents consuming these fish to the local population, due to the fact that its cancer risk (CR) value exceeded the upper limit of the acceptable risk levels (10(-4)) stipulated by the USEPA. PMID:23247527

  7. Landscape ecological security assessment based on projection pursuit in Pearl River Delta.

    PubMed

    Gao, Yang; Wu, Zhifeng; Lou, Quansheng; Huang, Huamei; Cheng, Jiong; Chen, Zhangli

    2012-04-01

    Regional landscape ecological security is an important issue for ecological security, and has a great influence on national security and social sustainable development. The Pearl River Delta (PRD) in southern China has experienced rapid economic development and intensive human activities in recent years. This study, based on landscape analysis, provides a method to discover the alteration of character among different landscape types and to understand the landscape ecological security status. Based on remotely sensed products of the Landsat 5 TM images in 1990 and the Landsat 7 ETM+ images in 2005, landscape classification maps of nine cities in the PRD were compiled by implementing Remote Sensing and Geographic Information System technology. Several indices, including aggregation, crush index, landscape shape index, Shannon's diversity index, landscape fragile index, and landscape security adjacent index, were applied to analyze spatial-temporal characteristics of landscape patterns in the PRD. A landscape ecological security index based on these outcomes was calculated by projection pursuit using genetic algorithm. The landscape ecological security of nine cities in the PRD was thus evaluated. The main results of this research are listed as follows: (1) from 1990 to 2005, the aggregation index, crush index, landscape shape index, and Shannon's diversity index of nine cities changed little in the PRD, while the landscape fragile index and landscape security adjacent index changed obviously. The landscape fragile index of nine cities showed a decreasing trend; however, the landscape security adjacent index has been increasing; (2) from 1990 to 2005, landscape ecology of the cities of Zhuhai and Huizhou maintained a good security situation. However, there was a relatively low value of ecological security in the cities of Dongguan and Foshan. Except for Foshan and Guangzhou, whose landscape ecological security situation were slightly improved, the cities had reduced

  8. [Influence of Burning Fireworks on Air Quality During the Spring Festival in the Pearl River Delta].

    PubMed

    Zhao, Wei; Fan, Shao-jia; Xie, Wen-zhang; Sun, Jia-ren

    2015-12-01

    Based on data from the air quality monitoring stations in the Pearl River Delta during the 2015 Spring Festival, the regional air quality was investigated and the impact of burning fireworks on urban air quality was assessed. The results showed that: Zhaoqing was the worst polluted city in PM₁₀, PM₂.₅, SO₂ and CO in terms of concentrations in the region during the period, Huizhou was the worst polluted city in O₃ and Guangzhou was the most polluted city in NO₂ at the same time. Compared to the data of last year, the SO₂, NO₂, CO, PM₁₀ and PM₂.₅ concentrations had decreased significantly, but the O₃ concentration had increased during the Spring Festival. Burning fireworks during the Spring Festival were mainly concentrated in the suburbs. The concentrated discharge of fireworks made the SO₂, PM₁₀ and PM₂.₅ concentrations increased significantly in the New Year's Eve night, even multiplied, but had no significant effect on CO, O₃ and NO₂. The rapid decline in PM₂.₅/PM₁₀ proportion was caused by the discharge of fireworks, and the ratio of PM₂.₅/PM₁₀ reached the minimum when concentration of particles reached the peak. By assessing, the maximum contribution of hourly concentration from burning fireworks in each city was between 16 µg · m⁻³ and 65 µg · m⁻³ for PM₂.₅, between 28 µg · m⁻³ and 138 µg · m⁻³ for PM₁₀ and between 9 µg · m⁻³ and 43 µg · m⁻³ for SO₂. PMID:27011968

  9. [Distribution and partition of polycyclic aromatic hydrocarbons in surface water from the Pearl River estuary].

    PubMed

    Luo, Xiao-jun; Chen, She-jun; Yu, Mei; Mai, Bi-xian; Sheng, Guo-ying; Fu, Jia-mo

    2008-09-01

    To obtain the temporal and spatial distribution and partition of PAH between water and particles in coastal area, water samples were collected from the Pearl River Estuary in July 2002 (summer) and April 2003 (spring) and polycyclic aromatic hydrocarbons (PAHs) were analysed with GC-MS in the present study. Total PAH concentrations in water samples were higher in spring (c(p): 4.0-39.1 ng/L; c(w): 15.9-184.2 ng/L) than in summer (c(p): 2.6-26.6 ng/L; c(w): 13.0-28.3 ng/L). Suspended particle matter (SPM) content, photogradation and riverine discharge were the major factors controlling the PAH concentrations in water. The 3-ring PAHs were the dominant PAHs in water samples. The 5 and 6 ring PAHs are more enriched in the inner estuary samples than in outside estuary samples, and the 3 ring PAHs are more enriched in summer samples than in spring samples. The differences in composition and source of SPM might be responsible for this observation. The partition coefficient (Kp) increased with the particular organic carbon content of SPM and salinity of water and decreased with the SPM content of samples, which were consistent with the PAH partition theory. A linear correlation between IgK(OC) and lgK(OW) were found in two sampling periods. The observed values of lgK(OC) exceed their predicted values calculated form linear free energy relationship between lgK(OC) and lgK(OW). PMID:19068615

  10. 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.

  11. Species diversity and distribution for phytoplankton of the Pearl River estuary during rainy and dry seasons.

    PubMed

    Huang, Liangmin; Jian, Weijun; Song, Xingyu; Huang, Xiaoping; Liu, Sheng; Qian, Peiyuan; Yin, Kedong; Wu, Madeline

    2004-10-01

    Based on data collected at 31 stations and 1 continuous station in the Pearl River estuary during cruises of July 1999 (rainy season) and January 2001 (dry season), this study examined taxonomic composition, abundance, and spatial distribution of phytoplankton. Results indicated 130 species of phytoplankton in the samples from the rainy season, and 132 species in the dry season. Among them, in the rainy season, 82 species of diatom, 39 fresh-water and half-fresh-water species and 41 species of red tide organisms were found. Within these, there were 54 tropical and sub-tropical species, 47 cosmopolitan species and 17 temperate species. The abundance of phytoplankton in the rainy season was higher than that of the dry season, with an average of 6.3 x 10(5) cells x L(-1) and 1.4 x 10(5) cells x L(-1), respectively. Diversity index (H') and evenness (J) were 2.47 and 0.57 in the rainy season, and 2.01 and 0.54 in the dry season. The dominant phytoplankton species in the rainy season was Skeletonema costatum with an average of 2.8 x 10(5) cells x L(-1) and 45.0% of the total phytoplankton abundance. In the dry season, Eucampia zoodiacus became the key dominant species (5.9 x 10(4) cells x L(-1)) when it was 43.47% of the total phytoplankton abundance. Distribution of the dominant species varied with salinity of sea-water, and their amounts correlated negatively with nutrients and zooplankton. PMID:15476837

  12. 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.

  13. Beryllium isotope geochemistry in tropical river basins

    SciTech Connect

    Brown, E.T.; Edmond, J.M. ); Raisbeck, G.M.; Bourles, D.L.; Yiou, F. ); Measures, C.I. )

    1992-04-01

    The distributions of beryllium-9 and beryllium-10 in rivers within the Orinoco and Amazon basins have been examined to extend the understanding of their geochemical cycles and to develop their use both in geochronometry, and in studying erosional processes. Analyses of {sup 9}Be in dissolved and suspended material from rivers with a wide range of chemical compositions indicate that its geochemistry is primarily controlled by two major factors: (1) its abundance in the rocks of the watershed and (2) the extent of its adsorption onto particle surfaces. The relative importance of these parameters in individual rivers is determined by the extent of interaction with flood-plain sediments and the riverine pH. This understanding of {sup 9}Be geochemistry forms a basis for examination of the geochemical cycling of {sup 10}Be. In rivers which are dominated by interaction with sediments, the riverine concentration of dissolved {sup 10}Be is far lower than that in the incoming rainwater, indicating that a substantial proportion of it is retained within the soils of the basin or is adsorbed onto riverine particles. However, in acidic rivers in which the stable dissolved Be concentration is determined by the Be level in the rocks of the drainage basin, dissolved {sup 10}Be has essentially the same concentration as in precipitation. These observations imply that the soil column in such regions must be saturated with respect to {sup 10}Be, and that the ratio of the inventory to the flux does not represent an age, as may be the case in temperate latitudes, but rather a residence time.

  14. Delineation of the sources and sinks of heterogeneously distributed methane in the Pearl River and its estuary

    NASA Astrophysics Data System (ADS)

    Wang, J.; Xie, W.; Wei, Y.; Zhang, C.

    2013-12-01

    Methane in low temperature environments is mostly produced by methanogens. Sharp decrease in methane concentration has been observed from freshwater to marine water in coastal regions. The goal of this study was to delineate the sources and sinks of methane from the lower Pearl River (including, North, West, and East segments) and its estuary along a salinity gradient (0.0 % to 3.4%). Methane concentration in lower Pearl River ranged from 50.1 to 10578 nmol L-1 in the winter (average = 565.5 × 1464.9 nmol L-1) and from 38.4 to 974.1 nmol L-1 in the summer (average = 179.6 × 165.7 nmol L-1). In the estuary, however, methane concentration was 5-10 folds lower in winter and 3-8 folds lower in summer. The sea-to-air methane flux was also much higher in the fresh water (3159.6 umol/d.m2) than in the estuary (528.1 umol/d.m2). Abnormally high methane concentrations and methane flux in the East Pearl River appear to be associated with effluents of industrial or municipal wastes. DNA sequencing of the archaeal 16S rRNA gene indicates predominance of methanogens in the freshwater and their disappearance in the estuary. This is supported by the archaeal lipoid analysis, which showed the predominance of archaeol and caldarchaeol that characterize the methanogens. It is unknown, however, how aerobic (bacteria) and anerobic (archaea) methanotrophs may be involved in the oxidation of methane in the estuary environment where methane consumption is apparently occurring.

  15. Use of Reflectance Ratios as a Proxy for Coastal Water Constituent Monitoring in the Pearl River Estuary

    PubMed Central

    Fang, Li-Gang; Chen, Shui-Sen; Li, Dong; Li, Hong-Li

    2009-01-01

    Spectra, salinity, total suspended solids (TSS, in mg/L) and colored dissolved organic matter (CDOM, ag(400) at 400 nm) sampled in stations in 44 different locations on December 18, 19 and 21, in 2006 were measured and analyzed. The studied field covered a large variety of optically different waters, the absorption coefficient of CDOM ([ag(400)] in m-1) varied between 0.488 and 1.41 m-1, and the TSS concentrations (mg/L) varied between 7.0 and 241.1 mg/L. In order to detect salinity of the Pearl River Estuary, we analyzed the spectral properties of TSS and CDOM, and the relationships between field water reflectance spectra and water constituents' concentrations based on the synchronous in-situ and satellite hyper-spectral image analysis. A good correlation was discovered (the positive correlation by linear fit), between in-situ reflectance ratio R680/R527 and TSS concentrations (R2 = 0.65) for the salinity range of 1.74-22.12. However, the result also showed that the absorption coefficient of CDOM was not tightly correlated with reflectance. In addition, we also observed two significant relationships (R2 > 0.77), one between TSS concentrations and surface salinity and the other between the absorption coefficient of CDOM and surface salinity. Finally, we develop a novel method to understand surface salinity distribution of estuarine waters from the calibrated EO-1 Hyperion reflectance data in the Pearl River Estuary, i.e. channels with high salinity and shoals with low salinity. The EO-1 Hyperion derived surface salinity and TSS concentrations were validated using in-situ data that were collected on December 21, 2006, synchronous with EO-1 Hyperion satellite imagery acquisition. The results showed that the semi-empirical relationships are capable of predicting salinity from EO-1 Hyperion imagery in the Pearl River Estuary (RMSE < 2‰). PMID:22389623

  16. Heavy metals associated with reduced sulfur in sediments from different deposition environments in the Pearl River estuary, China.

    PubMed

    Chen, Fanrong; Yang, Yongqiang; Zhang, Derong; Zhang, Ling

    2006-06-01

    Distribution of acid volatile sulfur (AVS) and the simultaneously extracted metals (SEM: Cu, Pb, Zn, Cd, Ni) in sediment profiles has been studied at five sites in Pearl River estuary, China. Of the five sampling locations, Nos.1 and 2 are in the middle shoal, Nos.3 and 4 in the west shoal and No. 5 locates to the south of the estuary. The AVS content in the sediments of the middle shoal varies in a small range (0.25-4.06 micromol g(-1)), while that of west shoal increases with depth from 0 to ultimately 26.09 micromol g(-1). The SEM concentration in the sediment profiles at location Nos. 1, 2 and 5 is generally in the range of 0.95+/-0.2 micromol g(-1) with a slight upward increase, while that in the sediment of west shallows are much higher (1.43-2.42 micromol g(-1)) with a significant upward increase, especially in the upper layer of ca. 15 cm. The observed upward increase of SEM content at all the sites implies that heavy metal contamination of sediment in the Pearl River estuary is increasing. Calculations of the excess heavy metal content which is defined by SEM-AVS molar difference suggests that the upper sediment in the Pearl River estuary, especially on the west shallows, could be a source of heavy metal contaminants and may cause toxicity to the benthos. The site-specific distribution patterns in the AVS and SEM profiles were interpreted according to the hydrogeochemistry of deposition environments. PMID:16767564

  17. 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.

  18. Spatial and temporal variability in nitrous oxide and methane emissions in urban riparian zones of the Pearl River Delta.

    PubMed

    Zhang, Taiping; Huang, Xinyu; Yang, Yue; Li, Yuelin; Dahlgren, Randy A

    2016-01-01

    Spatial and temporal variability in nitrous oxide and methane emissions were quantified in three seasons using closed chambers in three riparian zone locations of three branches of the Pearl River, Guangzhou, China. The sampling sites were selected in a rapidly developing urban area of Guangzhou and represented a pollution gradient. The results show that urban riparian landscapes can be large source areas for CH4 and N2O, with fluxes of -0.035∼32.30 mg m(-2) h(-1) and -5.49∼37.31 μg m(-2) h(-1), respectively. River water quality, sediment texture, and NH4-N and NO3-N concentrations correlated with N2O and CH4 emission rates. The riparian zones of the more seriously polluted tributaries showed higher greenhouse gas fluxes than that of the less polluted main stem of the Pearl River. Rain events increased emissions of CH4 by 6.5∼21.3 times and N2O by 2.2∼5.7 times. The lower concentrations of heavy metals increased the activity of denitrifying enzymes while inhibited the methane producing pathways. This work demonstrates that rapidly developing urban areas are an important source of greenhouse gas emissions, which is conditioned by various environmental factors. PMID:26377967

  19. Distributions of Core- and Polar- Archaeal Lipids in the Lower Pearl River and Estuary: Implications for TEX86 Proxies

    NASA Astrophysics Data System (ADS)

    Wang, J.; Zhang, C.; Zhu, C.; Wei, Y.; Dong, H.; Liu, W.

    2011-12-01

    Core isoprenoidal glycerol dibiphytanyl dlycerol tetraethers (C-iGDGTs) are the most widespread archaeal lipids in sediments and water, and have been used to construct a molecular proxy, TEX86, for studying past sea surface temperatures. However, recent analyses of intact polar (IP)-iGDGTs that are indicative of living archaea suggest that IP-iGDGTs produced in situ in marine sediments may subsequently convert IP-iGDGTs to C-iGDGTs after the cell death, thus compromising the validity of TEX86 for paleoclimate research. To help address this question, we investigated the distribution and abundance of IP- and C- iGDGTs in suspended particulates and surface sediments from the lower Pearl River and estuary. Our results show a strong positive correlation between the C- and P-iGDGTs pools, especially the iGDGT-0 (R2 = 0.786, p<0.001), iGDGT-1 (R2 = 0.920, p<0.001), and crenarchaeol (R2 = 0.871, p<0.001), suggesting that aquatic archaeal lipids are mostly derived from in situ production in the river water and/or sediments, and a minor fraction of these lipids are terrestrially-sourced. Methanogens (belonging to Euryarchaeota) may be an important source of iGDGTs in water and sediments of Pearl River estuary, which may further complicate the use of TEX86 that is based on planktonic Crenarchaeota.

  20. Sustainability Within the Great Monsoon River Basins

    NASA Astrophysics Data System (ADS)

    Webster, P. J.

    2014-12-01

    For over five millenia, the great monsoon river basins of the Ganges, Brahmaputra and Indus have provided for great and flourishing agrarian civilizations. However, rapid population growth and urbanization have placed stress on the rural sector causing the use of land that is more prone for flood and drought. In addition, increased population and farming have stressed the availability of fresh water both from rivers and aquifers. Additionally, rapid urbanization has severely reduced water quality within the great rivers. Added to these problems is delta subsidence from water withdrawal that, at the moment far surpasses sea level rise from both natural and anthropogenic effects. Finally, there appear to be great plans for river diversion that may reduce fresh water inflow into the Brahmaputra delta. All of these factors fall against a background of climate change, both anthropogenic and natural, of which there is great uncertainty. We an attempt a frank assessment assessment of the sustainability of society in the great basins and make some suggestions of factors that require attention in the short term.

  1. Abundance and Bulk Composition of DOM in the Lower Mississippi and Pearl Rivers (USA)

    NASA Astrophysics Data System (ADS)

    Duan, S.; Bianchi, T. S.; Shiller, A. M.; Dria, K.; Hatcher, P. G.

    2005-05-01

    Here we report on temporal changes in the composition of dissolved organic carbon (DOC) and nitrogen (DON) collected in the tidal freshwater region of the lower Mississippi and Pearl Rivers (MR and PR) (USA). Bulk stable carbon isotopes and 13C nuclear magnetic resonance (NMR) spectrometry were used to examine the composition of high molecular weight (< 0.2 µm > 1 kDa) dissolved organic matter (HMW DOM). Monthly water samples were collected at one station in each river from August 2001 to July 2003. Surveys of spatial variability (225 km downstream in the MR and from Jackson to Stennis Space Center in the PR) in total DOC and DON were also conducted in both rivers in June 2003. Higher total DOC (336 to 1156 uM), DON (9.3 to 59.5 uM), % HMW DOM (25 to 47 %), ultraviolet (UV) absorption (0.13 to 0.70 /m), and more depleted delta-15N (0.76 to 2.16 per mil) delta-13C (-25.1 to -28.0 permil) were observed in the PR than in the lower MR (223 to 380 uM, 6.1 to 13.4 uM, 16 to 38 %, 0.08 to 0.17 /m, 0.76 to 2.16 permil, -25.7 to -27.1 permil, respectively). 13C-NMR spectra revealed that alkyl and carbohydrate carbons were dominant in HMW DOC in both rivers. However, a significantly lower percentage of aromatic C (13.2 to 16.6 %) and higher carboxyl C (17.1 to 25.8 %) were observed in the lower MR than in the PR (16.9 to 21.3 % and 12.3 to 20.9 %). Total DOC, DON, HMW DOM, and percent aromaticity of HMW DOM were higher in the PR during local flooding events, and lower during low discharge, indicating a coupling between local carbon inputs (soil and wetlands) and regional precipitation events in the PR. Conversely, seasonal variability of total DOC, DON, and HMW DOM in the lower MR was controlled by spatial variability of an integrative signal from watershed inputs and in-situ production from upriver sources, resulting in a more phytoplankton-derived 13C-NMR signature of HMW DOM. Spatially, very little change occurred in total DOC (259 to 282 uM) and DON (8.85 to 13.3 u

  2. Sprague River geomorphology studies, Klamath Basin, Oregon

    NASA Astrophysics Data System (ADS)

    McDowell, P. F.; O'Connor, J. E.; Lind, P.

    2005-12-01

    The Sprague River drains 4050 square kilometers with a mean annual discharge of 16.3 m3/s before emptying into the Williamson River and then upper Klamath Lake in southcentral Oregon. The alternating wide alluvial segments and narrow canyon reaches of this 135-km-long westward flowing river provide for a variety of valued ecologic conditions and human uses along the river corridor, notably fisheries (including two endangered species of suckers, and formerly salmon), timber harvest, agriculture, and livestock grazing. The complex history of land ownership and landuse, water control and diversion structures, and fishery alterations, provides several targets for attributing historic changes to channel and floodplain conditions. Recently, evolving societal values (as well as much outside money) are inspiring efforts by many entities to 'restore' the Sprague River watershed. In cooperation with the U.S. Fish and Wildlife Service, the Klamath Tribes, and many local landowners, we are launching an analysis of Sprague River channel and floodplain processes. The overall objective is to guide restoration activities by providing sound understanding of local geomorphic processes and conditions. To do this we are identifying key floodplain and channel processes, and investigating how they have been affected by historic floodplain activites and changes to the watershed. This is being accomplished by analysis of historic aerial photographs and maps, stratigraphic analysis of floodplain soils and geologic units, mapping of riparian vegetation conditions and changes, and quantitative analysis of high resolution LiDAR topography acquired for the entire river course in December 2004. Preliminary results indicate (1) much of the coarser (and more erodible) floodplain soils are largely composed of pumice deposited in the basin by the 7700 year BP eruption of Mount Mazama; and (2) the LiDAR digital elevation models provide a ready means of subdividing the river into segments with

  3. Occurrence and environmental risk of endocrine-disrupting chemicals in surface waters of the Pearl River, South China.

    PubMed

    Gong, Jian; Ran, Yong; Chen, Diyun; Yang, Yu; Ma, Xiaoxuan

    2009-09-01

    The occurrence and environmental risk of endocrine-disrupting chemicals was investigated in the surface water samples of the Zhujiang and Dongjiang rivers, Pearl River Delta (PRD) of South China. Thirty surface water samples were collected in the dry season and analyzed by using an MSTFA derivation and a GC-MS-SIM method. Concentrations of biphenol A (BPA) ranged from 43.5 to 639.1 ng L( - 1), and concentrations of estrone (E1) and 17beta-estradiol (E2) ranged from <1.5 to 8.2 ng L( - 1) and from <1.1 to 1.7 ng L( - 1), respectively. The spatial distribution of these chemicals was related to the discharge of domestic and industrial wastewater along the rivers. The highly significant correlation among BPA, E1, and dissolved organic carbon (DOC) might be related to their same contamination source and/or their association with colloidal organic carbon of DOC in the river samples. Compared with other studied rivers in the world, the estrogenic contamination in the investigated rivers was high for BPA and moderate for E1. As the average estrogenic activity in E2 activity equivalent (E2eq; 1.16 ng E2eq L( - 1)) for the target BAP, E1, and E2 combined with those for nonyphenol and octylphenol, which were previously reported, exceeds documented effect levels in the investigated river waters for some aquatic species, they may pose a high risk to the local aquatic organisms. PMID:18670899

  4. Scaling issues in sustainable river basin management

    NASA Astrophysics Data System (ADS)

    Timmerman, Jos; Froebich, Jochen

    2014-05-01

    Sustainable river basin management implies considering the whole river basin when managing the water resources. Management measures target at dividing the water over different uses (nature, agriculture, industry, households) thereby avoiding calamities like having too much, too little or bad quality water. Water management measures are taken at the local level, usually considering the sub-national and sometimes national effects of such measures. A large part of the world's freshwater resources, however, is contained in river basins and groundwater systems that are shared by two or more countries. Sustainable river basin management consequently has to encompass local, regional, national and international scales. This requires coordination over and cooperation between these levels that is currently compressed into the term 'water governance' . Governance takes into account that a large number of stakeholders in different regimes (the principles, rules and procedures that steer management) contribute to policy and management of a resource. Governance includes the increasing importance of basically non-hierarchical modes of governing, where non-state actors (formal organizations like NGOs, private companies, consumer associations, etc.) participate in the formulation and implementation of public policy. Land use determines the run-off generation and use of irrigation water. Land use is increasingly determined by private sector initiatives at local scale. This is a complicating factor in the governance issue, as in comparison to former developments of large scale irrigation systems, planning institutions at state level have then less insight on actual water consumption. The water management regime of a basin consequently has to account for the different scales of water management and within these different scales with both state and non-state actors. The central elements of regimes include the policy setting (the policies and water management strategies), legal setting

  5. Outlet Works, from foreground: Deschutes River, Stilling Basin, Outlet Opening, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Outlet Works, from foreground: Deschutes River, Stilling Basin, Outlet Opening, Valve House, dam embankment, and Emergency Gates Control Tower, view to southwest - Wickiup Dam, Outlet Works, Deschutes River, La Pine, Deschutes County, OR

  6. Valve House, Stilling Basin, and Deschutes River with toe drain ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Valve House, Stilling Basin, and Deschutes River with toe drain visible as water fall on left bank, from top of dam embankment, view to north - Wickiup Dam, Outlet Works, Deschutes River, La Pine, Deschutes County, OR

  7. Role of pulsed winds on detachment of low salinity water from the Pearl River Plume: Upwelling and mixing processes

    NASA Astrophysics Data System (ADS)

    Chen, Zhaoyun; Pan, Jiayi; Jiang, Yuwu

    2016-04-01

    The detachment of low salinity water (LSW) from the Pearl River plume occurs frequently as revealed by in situ observations and satellite images, and plays an important role in cross-shore transport of the nutrient-rich plume water. In this study, the Regional Ocean Modeling System (ROMS) is used to simulate the LSW detachment process forced by realistic and idealized winds, and to explore its dynamical mechanisms. Modeling results show that the LSW detachment appears under a pulsed southwesterly wind, while tidal mixing modifies the size and salinity of the detached LSW. Strong pulsed wind causes the LSW to separate from the plume and move offshore quickly after the detachment. Under a pulsed northeasterly wind, however, the plume without separation of the LSW moves shoreward, indicating that the LSW detachment is sensitive to wind direction. In the plume region, upwelling develops under the forcing of the pulsed southwesterly wind, which transports high salinity bottom water to the surface layer, while the shear mixing in the upper layer further enhances the surface buoyancy flux, leading to appearance of high salinity water in the surface layer off the Pearl River estuary mouth, cutting off the eastward-spreading plume water, and resulting in the plume LSW detachment. Further analysis shows that the pulsed southwesterly wind induces positive local salinity change rate in the LSW detachment area. The pulsed upwelling-favorable wind with duration of 2-5 days is responsible for the detachment process.

  8. 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.

  9. Occurrence and phase distribution of polycyclic aromatic hydrocarbons in riverine runoff of the Pearl River Delta, China.

    PubMed

    Wang, Ji-Zhong; Nie, Yun-Feng; Luo, Xian-Lin; Zeng, Eddy Y

    2008-01-01

    The occurrence and phase distribution of polycyclic aromatic hydrocarbons (PAHs) in waters at the eight riverine outlets of the Pearl River Delta (China) were examined based on a monthly sampling program from March 2005 to February 2006. The total concentrations of PAHs in the aqueous phase and suspended particulate matter (SPM) combined ranged from 55.5 to 522 ng/L, at the mid level of the global values in rivers and estuaries. No clear temporal and spatial trends of PAH concentrations were found. However, the concentrations of PAHs associated with SPM coincided with the monthly precipitation of Guangzhou, indicating the importance of atmospheric deposition. The PAHs found in the region were likely derived from a combined pyrolytic and petrogenic origin, as suggested by the molecular indices of PAHs. Normalized partition coefficient (K(oc)) between water and SPM was correlated with octanol-water partition coefficient (K(ow)) to understand the environmental behavior of PAHs. PMID:18289609

  10. Amino acids in the Pearl River Estuary and adjacent waters: origins, transformation and degradation

    NASA Astrophysics Data System (ADS)

    Chen, Jianfang; Li, Yan; Yin, Kedong; Jin, Haiyan

    2004-10-01

    Two cruises were conducted in the Pearl River Estuary (PRE) and adjacent coastal waters during July 1999 and 2000 to investigate spatial variation, transformation and degradation of amino acids (AAs). Salinity, suspended sediments (SS), chl a, nutrients, dissolved organic carbon, particulate organic carbon, AAs, and hexosamines were measured and analyzed. Concentrations of particulate hydrolysable AAs (PHAAs), dissolved combined AAs and dissolved free AAs ranged from 0.41 to 12.6 μmol L-1, 1.1 to 4.0 μmol L-1 and 0.15 to 1.10 μmol L-1, respectively. AAs concentrations were low in waters of salinity <10, increased to the maximum in the estuarine and coastal plumes (salinity =10-25) and decreased beyond the coastal plume. There was a region where PHAAs were maximum, which coincided with the region of the chl a maximum and depletion of dissolved inorganic phosphorus in the coastal plume south of Hong Kong. This indicates that most of the AAs in estuarine and coastal waters were produced through phytoplankton production and AAs might be a temporary sink for inorganic nitrogen. The ratios of AAs/HAs and glucosamine/galactosamine (Glc-NH2/Gal-NH2) were on average, 26.0 and 3.8, respectively, in biogenic particulate matter (chl a >5 μg L-1 and SS<10 mg L-1), decreased in turbid particles (SS>20 mg L-1) and reached the lowest values of 5.8 and 1.4 in sediments. In particular, the ratios of AAs/HAs, Glc-NH2/Gal-NH2 were low in the upper or northwest side of the estuary where turbidity was high. This indicated that these AAs were "old", likely due to resuspension of refractory organic matter from sediments or zooplankton grazing modification and bacterial reworking as the salt wedge advanced upstream near the bottom. Apparently, the dynamics of AAs in the PRE appeared to be governed by biological production processes and estuarine circulation in the estuary. As the chl a maximum developed downstream in the estuarine and coastal plume and the salt wedge moved upstream at

  11. 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

  12. Sources of excess urban carbonaceous aerosol in the Pearl River Delta Region, China

    NASA Astrophysics Data System (ADS)

    Zheng, Mei; Wang, Fu; Hagler, G. S. W.; Hou, Ximei; Bergin, Michael; Cheng, Yuan; Salmon, L. G.; Schauer, James J.; Louie, Peter K. K.; Zeng, Limin; Zhang, Yuanhang

    2011-02-01

    Carbonaceous aerosol is one of the important constituents of fine particulate matter (PM 2.5) 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 organic carbon (OC) ranged from 3.52 to 7.87 μg m -3 in Hong Kong and 4.14-20.19 μg m -3 in the PRD from simultaneous measurements at three sites in HK and four sites in the PRD. Compared to the PRD, the spatial distribution of carbonaceous aerosol in Hong Kong was relatively homogeneous. Sources contributing to excess OC in the PRD were examined, which is the difference between OC concentrations measured at the PRD sites to the average level in Hong Kong. Eight primary sources contributing to excess OC were identified with chemical mass balance modeling in a combination with molecular markers analyzed by gas chromatography/mass spectrometry. Excess OC at Guangzhou, the capital city of Guangdong province, was consistently high, ranging from 9.77 to 13.6 μg m -3. Four primary sources including gasoline engine exhaust, diesel engine exhaust, biomass burning, and coal combustion accounted for more than 50% of excess OC in the PRD, especially in December (up to 76%). Mobile source emissions alone can contribute about 30% of excess OC. The unexplained or other excess OC was the highest at the rural site, but in general less than 20% at other sites. The coal combustion source contribution was unique in that it exhibited relatively homogeneous spatial distribution, indicating it was still an important source of carbonaceous aerosol in the PRD (17% of excess OC) during the study period. This analysis revealed that primary emissions are important sources of excess OC in the PRD and there is a need to reduce the emissions of mobile sources, biomass burning, and coal combustion in order to improve air quality in southern China.

  13. Tracer-based estimation of secondary organic carbon in the Pearl River Delta, south China

    NASA Astrophysics Data System (ADS)

    Ding, Xiang; Wang, Xin-Ming; Gao, Bo; Fu, Xiao-Xin; He, Quan-Fu; Zhao, Xiu-Ying; Yu, Jian-Zhen; Zheng, Mei

    2012-03-01

    Fine particles (PM2.5) were collected using filter-based high-volume samplers during summer-winter 2008 at a rural site in the central Pearl River Delta (PRD), south China, to determine typical secondary organic aerosol (SOA) tracers from significant biogenic (isoprene, monoterpenes, and sesquiterpenes) and anthropogenic (aromatics) precursors. Average isoprene SOA tracers were significantly higher during summer (126 ng m-3) than during fall-winter (25.1 ng m-3), owing largely to the higher isoprene emission and reaction rates in summer. Average monoterpene SOA tracers during summer (11.6 ng m-3) and fall-winter (16.4 ng m-3) showed much less difference compared to isoprene SOA tracers, probably resulting from the counteracting effects of temperature on the precursor emission/tracer formation and on gas/particle partitioning. The concentrations of the aromatics' SOA tracer (2,3-dihydroxy-4-oxopentanoic acid) ranged from 1.70 to 52.0 ng m-3 with an average of 15.1 ng m-3, which was the highest reported in ambient air. The secondary organic carbon (SOC) estimated by the SOA-tracer method averaged 3.07 μg C m-3 in summer and 2.00 μg C m-3 in fall-winter, contributing 38.4% and 8.7% to OC, respectively. During summer, aromatics-SOC and isoprene-SOC reached 2.25 ± 1.5 μg C m-3 and 0.64 ± 0.7 μg C m-3 and accounted for 76% and 18% of the estimated SOC, respectively, while during fall-winter, aromatics-SOC (1.64 ± 1.4 μg C m-3) was dominant with a share of 79% in total estimated SOC. These results indicated that anthropogenic aromatics were dominant SOC precursors in the highly industrialized and urbanized PRD region. During summer, SOC levels estimated by elemental carbon (EC) tracer method were not only consistent with but also correlated well with those by SOA-tracer method. During fall-winter, however, SOC by SOA-tracer method was only about one third of that by EC-tracer method. Their gaps were significantly correlated with the biomass burning tracer

  14. Bacterial Investigation of Ammonium-rich Sediment in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Liu, K.; Chunbo, H.; Jiao, J. J.; Jidong, G.

    2011-12-01

    High ammonium loading of groundwater is a major concern because of the potential toxicity to ecosystem and human health. As one of the most complex large-scale delta systems in China, Pearl River Delta (PRD) was reported to have the highest ammonium concentration for natural groundwater ever reported globally. In this research, borehole SD14 was drilled through the aquitard into the basal aquifer in the PRD. 16S rRNA gene library construction and Denaturing Gradient Gel Electrophoresis (DGGE) analysis were conducted to reveal bacterial community variation of different geology strata. A total of 161 clones from three 16S rRNA libraries were sequenced and clustered into 55 distinct operational taxonomic units (OTU) at 3% cutoff. The phylogenetic analysis indicated that the predominant bacterial phylum was Proteobacteria (50.9%), followed by Chloroflexi (16.8%), Acidobacteria (4.38%) and Firmicutes (3.73%). In the sediment samples from SD14 at the depths of 6.9m, 22.5m and 37.4m, Proteobacteria made up 60.3%, 42.0% and 35.3% of the communities respectively, showing a declining ratio with the depth. Most of the bacteria in all the samples were previously discovered in marine environments, indicating that SD14 used to be in a marine sedimentary environment. Bacteria associated with iron oxidation and nitrogen fixing were found in the sample at 6.9 m, while in the other two samples there existed bacteria which were associated with methane cycling, sulfate reducing and denitrifying. The DGGE results showed that microbial community structures varied significantly with the increase of depth, and that Delftia acidovorans, a species of Proteobacteria which was able to reduce nitrate to nitrite, was the predominant species in samples at 22.5 and 37.4 m, suggesting ammonium as a control factor shaping the bacterial community. The results of this research provided important information of the bacteria in the PRD sediments. High bacterial diversity was observed in samples, and

  15. [Methyl tert-butyl ether (MTBE) in atmosphere of the Pearl River Delta, China].

    PubMed

    Wang, Bo-guang; Shao, Min; Zhang, Yuan-hang; Lü, Wan-Ming; Zhou, Yan

    2007-07-01

    The concentration of methyl tert-butyl ether (MTBE) and its spatio-temporal distribution were researched in atmosphere of the Pearl River Delta (PRD) by sampling with air sampling canisters and analyzing with pre-concentrator and gas chromatograph-mass spectrum instrument. The results showed that 1) MTBE could be prevalently checked in atmosphere of traffic area, industrial area, residential area and commercial area of the PRD, and its range of hourly average concentration in the long-term observation was from 0 - 1.250 microg m(-3), the summer had more serious pollution than the spring, and urban was the central area of high MTBE concentration, and suburban in the downwind was obviously polluted by the urban air. 2) During the enhanced observation in summertime, the diurnal average concentration of Guangzhou urban site was (1.520 +/- 0.370) microg m(-3), which was about 7 times of Huadou site in the downwind of Guangzhou and over 100 times of Conghua site in the background of Guangzhou. In urban, 2 peak values appeared in the period of 10:00 - 12:00 and 16:00 - 18:00 respectively, and the nighttime had the lowest average concentration, but the suburban in the downwind had the peak value in the nighttime. 3) During the enhanced observation in wintertime, the diurnal average concentration of Guangzhou urban site was (0.950 +/- 0.240) microg m(-3), which was 3.6 times of Xinken site in the downwind of Guangzhou. Several peak values appeared on the diurnal variation, the high concentration period of urban was in 18:00 - 22:00, and that of suburban was in 04:00 - 10:00 of the next day. 4) When it was weak sunshine, the concentration of MTBE beside the urban traffic roadside was decreasing with the height increasing, but when it was strong sunshine, it was increasing with the height increasing. So, except the original emission from the automobiles, MTBE still had the secondary pollution sources formed by air photochemical reaction. PMID:17891978

  16. Aerosol size distribution characteristics of organosulfates in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Kuang, Bin Yu; Lin, Peng; Hu, Min; Yu, Jian Zhen

    2016-04-01

    Organosulfates (OSs) have been detected in various atmospheric environments, but their particle size distribution characteristics are unknown. In this work, we examined their size distributions in ambient aerosols to gain insights into the formation processes. Size-segregated aerosol samples in the range of 0.056-18 μm were collected using a ten-stage impactor at a receptor site in Hong Kong in both summer and winter and in Nansha in the Pearl River Delta in winter. The humic-like substances fraction in the size-segregated samples was isolated and analyzed using electrospray ionization coupled with an Orbitrap Ultra High Resolution Mass Spectrometer. Through accurate mass measurements, ∼190 CHOS and ∼90 CHONS formulas were tentatively identified to be OS compounds. Among them, OS compounds derived from isoprene, α-/β-pinene, and limonene and alkyl OSs having low double bond equivalents (DBE = 0,1) and 0-2 extra O beyond those in -OSO3 were found with high intensity. The biogenic volatile organic compounds-derived OS formulas share a common characteristic with sulfate in that the droplet mode dominated, peaking in either 0.56-1.0 or 1.0-1.8 μm size bin, reflecting sulfate as their common precursor. Most of these OSs have a minor coarse mode, accounting for 0-45%. The presence of OSs on the coarse particles is hypothesized to be a result of OSs on small particle (<0.32 μm) coagulating with coarse particles, as the abundance ratios of OS to non-sea-salt sulfate present on the coarse particles were similar to those on particles <0.32 μm. Among a few pairs of CHONS and CHOS that could be linked up through hydrolysis of a nitrooxy group in the CHONS form (e.g., m/z 294: C10H16O7NS- vs. m/z 249 C10H17O5S- from α/β-pinene, differing by (+H2O-HNO3)), the CHONS compounds had an enhanced coarse mode presence. This could be interpreted as a result of slower hydrolysis of the CHONS compounds on the alkali coarse particles. The low DBE alkyl OS compounds have a

  17. 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

  18. [Distribution of Regional Pollution and the Characteristics of Vertical Wind Field in the Pearl River Delta].

    PubMed

    Liu, Jian; Wu, Dui; Fan, Shao-jia

    2015-11-01

    Based on the data of hourly PM2.5 concentration of 56 environmental monitoring stations and 9 cities over the Pearl River Delta (PRD) region, the distributions of PM2.5 pollution in PRD region were analyzed by systematic cluster analysis and correlational analysis. It was found that the regional pollution could be divided into 3 types. The first type was the pollution occurred in Dongguan, Guangzhou, Foshan and Jiangmen (I type), and the second type was the pollution occurred in Zhongshan, Zhuhai, Shenzhen and Huizhou (II type), while the last type was the pollution only occurred in Zhaoqing (III type). During the study period, they occurred 47, 7 and 128 days, respectively. During events of pollution type I, except Zhuhai, Shenzhen and Huizhou, the PM2.5 concentrations of other cities were generally high, while the PM2.5 concentration in whole PRD region was over 50.0 μg x m(-3) during events of pollution type II. The regions with higher PM2.5 concentration was mainly concentrated in Zhaoqing, Guangzhou and Foshan during events of pollution type III. The wind data from 4 wind profile radars located in PRD region was used to study the characteristics of vertical wind field of these 3 pollution types. It was found that the wind profiles of type I and III were similar that low layer and high layer were controlled by the southeast wind and the southwest wind, respectively. For type II, the low layer and high layer were influenced by northerly wind and westerly wind, respectively. Compared with other types, the wind speed and ventilation index of type II. were much higher, and the variation of wind direction at lower-middle-layer was much smaller. When PRD region was influenced by northerly winds, the PM2.5 concentration in the entire PRD region was higher. When PRD region was controlled by southeast wind, the PM2.5 concentrations of I and II areas were relatively lower, while the pollution in III area was relatively heavier. PMID:26910982

  19. ANCIENT EARTHWORK IMPLEMENTS AND LAND DEVELOPMENT ON ONGA RIVER BASIN

    NASA Astrophysics Data System (ADS)

    Matsuki, Hirotada; Esaki, Tetsuro; Mitani, Yasuhiro; Ikemi, Hiroaki

    Present land use in a river basin is consequence of all land development in the past. This study is an attempt to recognize land development of a river basin, focusing on Onga river basin in ancient days (until 6th century). After confirming geological and topographical characteristics, the study pays attention to earthwork capability in Jomon, Yayo i and Kofun era. Leading-edge impl ements in each era support us to make an interpretation of ancient monuments' location and archaeological findings. Especially wooden how/spades in Yayoi era and iron blade edges in Kofu n era had typical impact to expand ricefield towards uncultivated area. The conclution indicates that the a dvanced earthwork implements enabled people shift main paddy field from lower lagoon area to upper alluvial terrains on Onga river basin through ancient days. This ancient land development history has much suggestions for today's river/river basin management.

  20. Powder River Basin: new energy frontier

    SciTech Connect

    Richards, B.

    1981-02-01

    The Powder River Basin in Wyoming represents a new energy frontier, where traditional ranch styles are giving way to boomtown development around new coal mines. Plans for extensive strip mining, coal trains and pipelines, and synthetic fuels plants will transform a 12,000 square mile area. The environmental and social impacts of trailer villages and the influx of new mores and life styles are already following traditional patterns for newcomers and long-time residents alike. Some local residents, however, are optimistic about the opportunities energy development will have. (DCK)

  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. PMID:24135865

  2. Developing a Science-based River Basin Management Plan for the Kharaa River Basin, Mongolia

    NASA Astrophysics Data System (ADS)

    Karthe, Daniel

    2013-04-01

    The Kharaa River Basin (KRB), which is located north of Mongolia's capital Ulaanbaatar and south of Lake Baikal, was chosen as a model region for the development and implementation of an integrated water resources management consisting of a monitoring concept, technical measures and a capacity development program (Karthe et al. 2012a). The basin of the Kharaa River covers an area of 14534 km² that is partly mountaineous and largely covered by taiga and steppe. At its outlet, the 362 km Kharaa River has a mean long-term annual discharge of 12.1 m³/s (MoMo Consortium 2009). A highly continental climate results in limited water resources, and rising water consumption coupled with the effects of climate and land use change may in the future exacerbate this water scarcity (Malsy et al. 2012; Karthe et al. 2013). Whereas the environment in the upper part of the catchment is in a relatively pristine state, the mid- and downstream sections of the river are characterized by nearby industry, mining activities and intensive agriculture (Menzel et al. 2011), resulting in declining water quality and ultimately a degradation of aquatic ecosystems (Hofmann et al. 2010; Hartwig et al. 2012). Moreover, it is a problem for the supply of major cities like Darkhan which largely rely on alluvial aquifers containing shallow-depth groundwater (Mun et al. 2008). Currently, there are alarming signs of water quality deterioration. With regard to water provision, a major problem is the poor state of distribution infrastructures which were often built in the 1960s and 70s (Scharaw & Westerhoff 2011). Rather little is currently known about the water quality supplied to end users; the latter is even more dubious in the city's informal ger districts (Karthe et al. 2012b). One important goal of the research and development project "Integrated Water Resources Management in Central Asia: Model Region Mongolia" lies in the implementation of a holistic concept for water resources monitoring and

  3. Controlling erosion in the Missouri River Basin

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-09-01

    The most pervasive conservation concern in the vast 510,000 square mile Missouri River basin in the western United States is excessive rates of wind erosion during dry periods, though conservation efforts can help control erosion, according to a 30 August report by the U.S. Department of Agriculture's (USDA) Conservation Effects Assessment Project. During some dry years, rates of wind erosion—which include nitrogen and phosphorus losses—can be higher than 4 tons per acre on 12% and higher than 2 tons per acre on 20% of the approximately 148,000 square miles of cultivated cropland, notes the report Assessment of the Effects of Conservation Practices on Cultivated Cropland in the Missouri River Basin. Between 2003 and 2006, conservation practices, including reducing tillage and building terraces, yielded about a 75% reduction in sediment runoff and phosphorus loss and a 68% reduction in nitrogen loss, according to the report. About 15 million acres in the region—18% of cultivated cropland—are considered to have either a high or moderate level of need for conservation treatment, and efforts in those areas in particular could result in additional reductions in sediment, phosphorus, and nitrogen loss, the report states.

  4. Drainage areas of streams in Arkansas, Ouachita River basin

    USGS Publications Warehouse

    Yanchosek, John J.; Hines, Marion S.

    1979-01-01

    Drainage areas, determined in accordance with procedure recommended by the Subcommittee on Hydrology of the Federal Inter-Agency River Basin Committee, are listed for points on streams in the Ouachita River basin in Arkansas. Points on the streams are identified by some topographic feature and by latitude and longitude. (USGS).

  5. COLUMBIA RIVER BASIN CONTAMINANT AQUATIC BIOTA AND SEDIMENT DATA

    EPA Science Inventory

    Numerous studies have been done to determine the levels of chemical contaminants in fish and sediment in the Columbia River Basin. These studies were done because of concern that releases of toxic Chemicals into the Columbia River Basin may be impacting health and the environment...

  6. 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.

  7. New vitrinite reflectance data for the Wind River Basin, Wyoming

    USGS Publications Warehouse

    Pawlewicz, Mark J.; Finn, Thomas M.

    2013-01-01

    The Wind River Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 7,400 square miles in central Wyoming. The basin is bounded by the Washakie Range and Owl Creek and southern Bighorn Mountains on the north, the Casper arch on the east and northeast, and the Granite Mountains on the south, and Wind River Range on the west. The purpose of this report is to present new vitrinite reflectance data collected mainly from Cretaceous marine shales in the Wind River Basin to better characterize their thermal maturity and hydrocarbon potential.

  8. Changes in sea level, water salinity and wetland habitat linked to the late agricultural development in the Pearl River delta plain of China

    NASA Astrophysics Data System (ADS)

    Zong, Yongqiang; Zheng, Zhuo; Huang, Kangyou; Sun, Yiying; Wang, Ning; Tang, Min; Huang, Guangqing

    2013-06-01

    Environmental change plays a significant role in the development of agriculture worldwide. The availability of wetland habitats and freshwater supply has been particularly important to the expansion and sustainability of rice-based economies. Some studies have emphasized the connections between societal changes and climatic fluctuations. However, recently emerged evidence has indicated the prevalence of human's initiatives. To tackle this complex issue, we employ a multi-proxy approach applying microfossil diatom/pollen and organic carbon isotopes collected from sediment cores of multiple locations to the reconstructions of palaeo-environment and identification of agricultural activity in the northern part of the Pearl River delta. Our study confirms the importance of environmental conditions, but also reveals initiatives taken by the agricultural communities in site selection for cultivation and settlements. Our results also show that freshwater wetland conditions became available in the most landward part of the deltaic plain along the West/North Rivers as early as 7000 years ago, since which wetland habitats expanded seawards as the deltaic shoreline advanced. By 2500 years ago, extensive freshwater wetlands already emerged in northwest part of the deltaic plain. However, before this time, economic activity within the deltaic basin was still predominantly based on fishing and gathering. This is possibly because the Neolithic communities did not need to adapt the labour-intensive cultivation due to the abundance of natural resources in the deltaic region, a strong contrast to what the communities in the Yangtze valley did 5000 years earlier. The agriculture was finally expanded about 2500-2200 years ago in a small area of marsh wetlands along a small river on the northern edge of the deltaic plain by a community migrated from the Yangtze basin. The agricultural activity was spread across the deltaic plain by about 1000 years ago, again as a result of the influx

  9. Water - Essential Resource of the Southern Flint River Basin, Georgia

    USGS Publications Warehouse

    Warner, Debbie; Norton, Virgil

    2004-01-01

    Introduction Abundant water resources of the Flint River Basin have played a major role in the history and development of southwestern Georgia. The Flint River-along with its tributaries, wetlands, and swamps-and the productive aquifers of the river basin are essential components of the area's diverse ecosystems. These resources also are necessary for sustained agricultural, industrial, and municipal activities. Increasing, and in some cases conflicting, demand for water makes careful monitoring and wise planning and management of southwestern Georgia's water resources critical to the ecological and economic future of the area. This poster presents the major issues associated with increasing competition for water resources in the southern Flint River Basin.

  10. Quality of water, Quillayute River basin, Washington

    SciTech Connect

    Fretwell, M.O.

    1984-01-01

    Ground water in the Quillayute River basin is generally of the calcium bicarbonate type, although water from some wells is affected by seawater intrusion and is predominantly of the sodium chloride type. The water is generally of excellent quality for most uses, with the exception of water in two wells which had iron concentrations that potentially could be tasted in beverages and could cause staining of laundry and porcelain fixtures. A comparison of the chemical compositions of ground and surface waters showed a strong similarity over a wide geographic area. Proportions of the major chemical constituents in the rivers of the basin were nearly constant despite concentration fluctuations in response to dilution from precipitation and snowmelt. River-water quality was generally excellent, as evaluated against Washington State water use and water-quality criteria. Fecal-coliform bacteria counts generally were much lower than the total-coliform bacteria counts, indicating that most of the coliform bacteria were of nonfecal origin and probably originated in soils. Fecal coliform concentrations in all the major tributaries met State water-quality criteria. Water temperatures occasionally exceeded criteria maximum during periods of warm weather and low streamflow; dissolved-oxygen concentrations were occasionally less than criteria minimum because of increased water temperature. Both conditions occurred naturally. Nutrient concentrations were generally low to very low and about the same as in streams from virgin forestland in the Olympic National Park. However, some slight increases in nutrient concentrations were observed, particularly in the vicinity of Mill Creek and the town of Forks; due to dilution and biological assimilation, these slightly elevated concentrations decreased as the water moved downstream. 35 refs., 24 figs., 16 tabs.

  11. Reserves in western basins: Part 1, Greater Green River basin

    SciTech Connect

    Not Available

    1993-10-01

    This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.

  12. The water footprint of agricultural products in European river basins

    NASA Astrophysics Data System (ADS)

    Vanham, D.; Bidoglio, G.

    2014-05-01

    This work quantifies the agricultural water footprint (WF) of production (WFprod, agr) and consumption (WFcons, agr) and the resulting net virtual water import (netVWi, agr) of 365 European river basins for a reference period (REF, 1996-2005) and two diet scenarios (a healthy diet based upon food-based dietary guidelines (HEALTHY) and a vegetarian (VEG) diet). In addition to total (tot) amounts, a differentiation is also made between the green (gn), blue (bl) and grey (gy) components. River basins where the REF WFcons, agr, tot exceeds the WFprod, agr, tot (resulting in positive netVWi, agr, tot values), are found along the London-Milan axis. These include the Thames, Scheldt, Meuse, Seine, Rhine and Po basins. River basins where the WFprod, agr, tot exceeds the WFcons, agr, tot are found in Western France, the Iberian Peninsula and the Baltic region. These include the Loire, Ebro and Nemunas basins. Under the HEALTHY diet scenario, the WFcons, agr, tot of most river basins decreases (max -32%), although it was found to increase in some basins in northern and eastern Europe. This results in 22 river basins, including the Danube, shifting from being net VW importers to being net VW exporters. A reduction (max -46%) in WFcons, agr, tot is observed for all but one river basin under the VEG diet scenario. In total, 50 river basins shift from being net VW importers to being net exporters, including the Danube, Seine, Rhone and Elbe basins. Similar observations are made when only the gn + bl and gn components are assessed. When analysing only the bl component, a different river basin pattern is observed.

  13. [Distribution Characteristics and Risk Assessment of Phthalic Acid Esters in Agricultural Products Around the Pearl River Delta. South China].

    PubMed

    Li, Bin; Wu, Shan; Liang, Jin-ming; Deng, Jie-fan; Wang, Ke; Liang, Wen-li; Zeng, Cai-ming; Peng, Si-qing; Zhang, Tian-bin; Yang, Guo-yi

    2016-01-15

    In order to investigate and assess the distribution of pathalic acid easters (PAEs) in agricultural products from typical areas of the Pearl River Delta, South China, 131 agricultural products were sampled for determination of 6 PAEs priority pollutants classified by the U. S. EPA by GC-FID. The results showed that the total contents of the PAEs (sigma PAEs) in agricultural products samples ranged from nd to 79.86 mg x kg(-1) and the mean value was 2.84 mg x kg(-1), with the detected ratio of 98.5%. The average concentrations of sigma PAEs in different types of agricultural products were ordered by vegetables (3.03 mg x kg(-1)) > rice (2.52 mg x kg(-1)) > fruits (1.26 mg x kg(-1)). The mean concentration of PAEs distributed in the four typical cities of the Pearl River Delta, and decreased in the sequence of Zhuhai (6.53 mg x kg(-1)) > Dongguan (2.59 mg x kg(-1)) > Huizhou (1.53 mg x kg(-1)) > Zhongshan (1.12 mg x kg(-1)). Di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) contributed more than 90. 8% of the total PAEs in samples, and were the main components of PAEs in agricultural products from the Pearl River Delta, with higher percentage contents and detected ratio. Meanwhile, the average concentrations of sigma PAEs in cabbage mustard, lettuce occurred in Zhuhai and Dongguan cities, followed by lettuce and leaf lettuce in the corresponding DEHP from Zhuhai city, both exceeded the suggested standards in U.S.A. and Europe and were of high health risk. There were significant differences among 14 various vegetables in the contents of the 6 PAEs compounds, and the sigma PAEs contents in cabbage mustard and lettuce as part of leafy vegetables were higher than those in other vegetables, while the lowest were detected in flowering cabbage and edible amaranth. Therefore, the type of vegetables and its growing environment exposed to the atmosphere and soil were the main factors that significantly affected their accumulation of

  14. Lake Murray, Fly and Strickland River Basins, Papua, New Guinea

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Lake Murray, a manmade reservoir, lies between the Fly and Strickland River Basins, Papua, New Guinea (7.0S, 141.5E). The region, photographed in sunglint, shows the water level in the reservoir and the full extent of the drainage basins of both river systems as the rivers meander through wide alluvial floodplains. Some forest clearing can be seen in places throughout the region, but most of the area remains in closed canopy forest.

  15. Analysis of the temporal and spatial distribution of water quality in China's major river basins, and trends between 2005 and 2010

    NASA Astrophysics Data System (ADS)

    Li, Jinjian; Meng, Xiaojie; Zhang, Yan; Li, Juan; Xia, Linlin; Zheng, Hongmei

    2015-09-01

    In this study, based on environmental quality monitoring data on 22 pollutants from 490 control sections, we analyzed the spatial distribution and temporal changes of water quality in ten Chinese river basins (watersheds) to reveal the trends from 2005 to 2010. We used a comprehensive water pollution index (WPI) and the proportions of this index accounted for by the three major pollutants to analyze how economic development has influenced water quality. Higher values of the index represent more serious pollution. We found that WPI was much higher for the Hai River Basin (1.83 to 5.60 times the averages in other regions). In the Yangtze River Basin, WPI increased from upstream to downstream. The indices of some provinces toward the middle of a basin, such as Hebei Province in the Hai River Basin, Shanxi Province in the Yellow River Basin, and Anhui Province in the Huai River Basin, were higher than those of upstream and downstream provinces. In the Songhua, Liao, and Southeast river basins, WPI decreased during the study period: in 2010, it decreased by 33.9%, 44.3%, and 67.2%, respectively, compared with the 2005 value. In the Pearl River, Southwest, and Inland river basins, WPI increased by 23.1%, 47.7%, and 38.5% in 2010, compared with 2005. A comparison of WPI with the GDP of each province showed that the water pollution generated by economic development was lightest in northwestern, southwestern, and northeastern China, and highest in central and eastern China, and that the water environment in some coastal regions were improving. However, some provinces (e.g., Shanxi Province) were seriously polluted.

  16. InSAR Detection of Ground Deformation in Megalopolises of Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Zhao, Qing

    Megalopolises in the Pearl River Delta, including Guangzhou and Hong Kong, have experienced various degree of ground subsidence. The causes can be divided into two categories: natural subsidence and the human-induced subsidence. Monitoring the ground subsidence can not only help people to find out the distributions in both spatial and temporal fields, but also guide people to minimize the hazard ahead. Thus, it is significant to monitor the ground subsidence accurately, timely and frequently. This dissertation research uses the Environmental Satellite Advanced Synthetic Aperture Radar (ENVISAT ASAR) data received at the Chinese University of Hong Kong Satellite Remote Sensing Receiving Station and SAR Interferometry (InSAR) technology as a powerful tool for large-scale ground deformation monitoring in Guangzhou and Hong Kong areas. Persistent Scatterer Interferometry (PSI) method is used to detect ground deformation in the urban area of Guangzhou city. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise) rate as high as -26 to -20 mma-1 (16-21 mma-1 ), implying that the study area is an active zone for ground deformation. Based on the point target map, a contour ground deformation rate map is generated. All the six ground collapse accidents that occurred in 2007-2008 fall within the subsidence zones, qualitatively validating the IPTA results. Ground subsidence and geological conditions on Datansha Island are examined. The results indicate that the local geological conditions and underground engineering projects are responsible for ground subsidence and ground collapse accidents occurred there. To interpret the distribution of active ground subsidence zones, a local geological map is used as a reference for generating a series of thematic maps. The results show that geological faults, rock distribution, over-development, and underground engineering projects may be four factors leading to the distribution of

  17. Nighttime observation and chemistry of HOx in the Pearl River Delta and Beijing in summer 2006

    NASA Astrophysics Data System (ADS)

    Lu, K.; Rohrer, F.; Holland, F.; Fuchs, H.; Brauers, T.; Oebel, A.; Dlugi, R.; Hu, M.; Li, X.; Lou, S.; Shao, M.; Zhu, T.; Wahner, A.; Zhang, Y.; Hofzumahaus, A.

    2013-12-01

    Nighttime HOx chemistry was investigated in two ground-based field campaigns (PRIDE-PRD2006 and CAREBEIJING2006) in summer 2006 in China by comparison of measured and modelled concentration data of OH and HO2. The measurement sites were located in a rural environment in the Pearl River Delta (PRD) under urban influence and in a suburban area close to Beijing, respectively. In both locations, significant nighttime concentrations of radicals were observed under conditions with high total OH reactivities of about 40-50 s-1 in PRD and 25 s-1 near Beijing. For OH, the nocturnal concentrations were within the range of (0.5-3) × 106 cm s-3 implying a signficant nighttime oxidation rate of pollutants in the order of several ppb per hour. The measured nighttime concentration of HO2 was about (0.2-5) × 108 cm -3 containing a significant, model-estimated contribution from RO2 as an interference. A chemical box model based on an established chemical mechanism is capable to reproduce the measured nighttime values of the measured peroxy radicals and kOH, but underestimates in both field campaigns the observed OH by about one order of magnitude. Sensitivity studies with the box model demonstrate that the OH discrepancy between measured and modelled nighttime OH can be resolved, if an additional \\chem{RO_x} production process (about 1 ppb h s-1) and additional recycling (RO2 → HO2 → OH) with an efficiency equivalent to 1 ppb NO is assumed. The additional recycling mechanism was also needed to reproduce the OH observations at the same locations during daytime for conditions with NO mixing ratios below 1 ppb. This could be an indication that the same missing process operates at day and night. In principle, the required primary c source can be explained by ozonolysis of terpenoids, which react faster with ozone than with OH in the nighttime atmosphere. However, the amount of these highly reactive biogenic VOC would require a strong local source, for which there is no direct

  18. Nighttime observation and chemistry of HOx in the Pearl River Delta and Beijing in summer 2006

    NASA Astrophysics Data System (ADS)

    Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Brauers, T.; Oebel, A.; Dlugi, R.; Hu, M.; Li, X.; Lou, S. R.; Shao, M.; Zhu, T.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A.

    2014-05-01

    Nighttime HOx chemistry was investigated in two ground-based field campaigns (PRIDE-PRD2006 and CAREBEIJING2006) in summer 2006 in China by comparison of measured and modeled concentration data of OH and HO2. The measurement sites were located in a rural environment in the Pearl River Delta (PRD) under urban influence and in a suburban area close to Beijing, respectively. In both locations, significant nighttime concentrations of radicals were observed under conditions with high total OH reactivities of about 40-50 s-1 in PRD and 25 s-1 near Beijing. For OH, the nocturnal concentrations were within the range of (0.5-3) × 106 cm-3, implying a significant nighttime oxidation rate of pollutants on the order of several ppb per hour. The measured nighttime concentration of HO2 was about (0.2-5) × 108 cm-3, containing a significant, model-estimated contribution from RO2 as an interference. A chemical box model based on an established chemical mechanism is capable of reproducing the measured nighttime values of the measured peroxy radicals and kOH, but underestimates in both field campaigns the observed OH by about 1 order of magnitude. Sensitivity studies with the box model demonstrate that the OH discrepancy between measured and modeled nighttime OH can be resolved, if an additional ROx production process (about 1 ppb h-1) and additional recycling (RO2 → HO2 → OH) with an efficiency equivalent to 1 ppb NO is assumed. The additional recycling mechanism was also needed to reproduce the OH observations at the same locations during daytime for conditions with NO mixing ratios below 1 ppb. This could be an indication that the same missing process operates at day and night. In principle, the required primary ROx source can be explained by ozonolysis of terpenoids, which react faster with ozone than with OH in the nighttime atmosphere. However, the amount of these highly reactive biogenic volatile organic compounds (VOCs) would require a strong local source, for which

  19. The agricultural water footprint of EU river basins

    NASA Astrophysics Data System (ADS)

    Vanham, Davy

    2014-05-01

    This work analyses the agricultural water footprint (WF) of production (WFprod,agr) and consumption (WFcons,agr) as well as the resulting net virtual water import (netVWi,agr) for 365 EU river basins with an area larger than 1000 km2. Apart from total amounts, also a differentiation between the green, blue and grey components is made. River basins where the WFcons,agr,tot exceeds WFprod,agr,tot values substantially (resulting in positive netVWi,agr,tot values), are found along the London-Milan axis. River basins where the WFprod,agr,totexceeds WFcons,agr,totare found in Western France, the Iberian Peninsula and the Baltic region. The effect of a healthy (HEALTHY) and vegetarian (VEG) diet on the WFcons,agr is assessed, as well as resulting changes in netVWi,agr. For HEALTHY, the WFcons,agr,tot of most river basins decreases (max 32%), although in the east some basins show an increase. For VEG, in all but one river basins a reduction (max 46%) in WFcons,agr,tot is observed. The effect of diets on the WFcons,agrof a river basin has not been carried out so far. River basins and not administrative borders are the key geographical entity for water management. Such a comprehensive analysis on the river basin scale is the first in its kind. Reduced river basin WFcons,agrcan contribute to sustainable water management both within the EU and outside its borders. They could help to reduce the dependency of EU consumption on domestic and foreign water resources.

  20. Progress in understanding the formation of fine particulate matter and ground-level ozone in Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Wang, Xuemei; Wang, Tao; Zheng, Junyu; Shao, Min; Wang, Xinming

    2015-12-01

    In the past three decades, the Pearl River Delta of China has been suffered from severe air pollution due to the rapid increase in energy consumption associated with industrialization and urbanization of the region. The number of hazy days, increased from below 20 days in a year before 1970, to more than 150 days a year during 1980 and 2000. The ground-level ozone levels have also on the rise, with hourly concentration of 160 ppbv being observed in Guangzhou and 201 ppbv in nearby Hong Kong (Zhang et al., 2008). The ozone pollution has been difficult to reduce even in air quality improvement program for the Guangzhou Asian Games (Liu et al., 2013).

  1. Numerical model to quantify biogenic volatile organic compound emissions: The Pearl River Delta region as a case study.

    PubMed

    Wang, Xuemei; Situ, Shuping; Chen, Weihua; Zheng, Junyu; Guenther, Alex; Fan, Qi; Chang, Ming

    2016-08-01

    This article compiles the actual knowledge of the biogenic volatile organic compound (BVOC) emissions estimated using model methods in the Pearl River Delta (PRD) region, one of the most developed regions in China. The developed history of BVOC emission models is presented briefly and three typical emission models are introduced and compared. The results from local studies related to BVOC emissions have been summarized. Based on this analysis, it is recommended that local researchers conduct BVOC emission studies systematically, from the assessment of model inputs, to compiling regional emission inventories to quantifying the uncertainties and evaluating the model results. Beyond that, more basic researches should be conducted in the future to close the gaps in knowledge on BVOC emission mechanisms, to develop the emission models and to refine the inventory results. This paper can provide a perspective on these aspects in the broad field of research associated with BVOC emissions in the PRD region. PMID:27521938

  2. The effects of vertebrate herbivory on plant community structure in the coastal marshes of the Pearl River, Louisiana, USA

    USGS Publications Warehouse

    Taylor, K.L.; Grace, J.B.

    1995-01-01

    In this study, we investigated the impacts of herbivory by the introduced aquatic herbivore, nutria (Myocastor coypus), on three marsh communities of the Pearl River using fenced exclosures and control plots. Although total community above-ground biomass was reduced by 30% in the plots exposed to herbivory as compared to those protected from herbivory, we found species richness to be unaffected. When individual species were examined within each community,Panicum virgatum andAster subulatus were found to be significantly reduced by herbivory in the freshwater community,Panicum virgatum andVigna luteola were significantly increased by herbivory in the oligohaline community, and no species were significantly affected in the mesohaline community. We conclude that this herbivory has some specific effects on some plant species as well as having a general community effect.

  3. Floods in the Skagit River basin, Washington

    USGS Publications Warehouse

    Stewart, James E.; Bodhaine, George Lawrence

    1961-01-01

    According to Indian tradition, floods of unusually great magnitude harassed the Skagit River basin about 1815 and 1856. The heights of these floods were not recorded at the time; so they are called historical floods. Since the arrival of white men about 1863, a number of large and damaging floods have been witnessed and recorded. Data concerning and verifying the early floods, including those of 1815 and 1856, were collected prior to 1923 by James E. Stewart. He talked with many of the early settlers in the valley who had listened to Indians tell about the terrible floods. Some of these settlers had referenced the maximum stages of floods they had witnessed by cutting notches at or measuring to high-water marks on trees. In order to verify flood stages Stewart spent many weeks finding and levelling to high-water marks such as drift deposits, sand layers in coves, and silt in the bark of certain types of trees. Gaging stations have been in operation at various locations on the Skagit River and its tributaries since 1909, so recorded peak stages are available at certain sites for floods occurring since that date. All peak discharge data available for both historical and recorded floods have been listed in this report. The types of floods as to winter and summer, the duration of peaks, and the effect of reservoirs are discussed. In 1899 Sterling Dam was constructed at the head of Gages Slough near Sedro Woolley. This was the beginning of major diking in the lower reaches of the Skagit River. Maps included in the report show the location of most of the dike failures that have occurred during the last 73 years and the area probably inundated by major floods. The damage resulting from certain floods is briefly discussed. The report is concluded with a brief discussion of the U.S. Geological Survey method of computing flood-frequency curves as applied to the Skagit River basin. The treatment of single-station records and a means of combining these records for expressing

  4. Zinc and Its Isotopes in the Loire River Basin, France

    NASA Astrophysics Data System (ADS)

    Millot, R.; Desaulty, A. M.; Bourrain, X.

    2014-12-01

    The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. In the upper basin, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The intermediate basin includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the Atlantic Ocean. Here, the Loire River drains the sedimentary series of the Paris Basin, mainly carbonate deposits. The lower Loire basin drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the Atlantic ocean. Here we are reporting concentration and isotope data for Zn in river waters and suspended sediments from the Loire River Basin. In addition, we also report concentration and isotope data for the different industrial sources within the Loire Basin, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of metal pollutants. Zinc isotopic compositions are rather homogeneous in river waters with δ66Zn values ranging from 0.21 to 0.39‰. This range of variation is very different from anthropogenic signature (industrial and/or agriculture release) that displays δ66Zn values between 0.02 to 0.14‰. This result is in agreement with a geogenic origin and the low Zn concentrations in the Loire River Basin (from 0.8 to 6 µg/L).

  5. Geochemical characteristics and fluxes of organic carbon 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

    2009-01-01

    This study aims to investigate the state of the riverine organic carbon in the Luodingjiang River under human impacts, such as reforestation, construction of reservoirs and in-stream damming. Seasonal and spatial characteristics of total suspended sediment (TSS), dissolved organic carbon (DOC) and particulate organic carbon (POC), as well as C/N ratios and the stable carbon isotopic signatures of POC (delta(13)C(POC)) were examined based on a one-year study (2005) in the basin-wide scale. More frequent sampling was conducted in the outlet of the river basin at Guanliang hydrological station. DOC and POC concentrations showed flush effects with increasing water discharge and sediment load in the basin-wide scale. Atomic C/N ratio of POC had a positive relationship with TSS in the outlet of the basin, indicating the reduced aquatic sources and enhanced terrestrial sources during the high flood season. However, the similar relationship was not observed in the basin-wide scale mainly due to the spatial distributions of soil organic carbon and TSS. delta(13)C(POC) showed obvious seasonal variations with enriched values in the period with high TSS concentration, reflecting the increased contribution from C(4) plants with enhanced soil erosion. The specific flux of the total organic carbon (2.30 t km(-)(2) year(-1)) was smaller than the global average level. The ratio of DOC to POC was 1.17, which is higher than most rivers under Asian monsoon climate regime. The organic carbon flux was estimated to decline with decreasing sediment load as a result of reforestation, reservoir construction and in-stream damming, which demonstrates the impacts of human disturbances on the global carbon cycle. PMID:19004473

  6. Resistivity sections, upper Arkansas River basin, Colorado

    USGS Publications Warehouse

    Zohdy, Adel A.R.; Hershey, Lloyd A.; Emery, Philip A.; Stanley, William D.

    1971-01-01

    A reconnaissance investigation of ground-water resources in the upper Arkansas River basin from Pueblo to Leadville is being made by the U.S. Geological Survey in cooperation with the Southeastern Colorado Water Conservancy District, and the Colorado Division of Water Resources, Colorado State Engineer. As part of the investigation, surface geophysical electrical resistivity surveys were made during the summer and fall of 1970 near Buena Vista and Westcliffe, Colo. (p1.1). The resistivity surveys were made to verify a previous gravity survey and to help locate areas where ground-water supplies might be developed. This report presents the results of the surveys in the form of two resistivity sections.

  7. Toxaphene levels in retail food from the Pearl River Delta area of South China and an assessment of dietary intake.

    PubMed

    Jiang, YouSheng; Liu, ZhiBin; Wu, DongTing; Zhang, JianQing; Zhou, Jian; Li, ShengNong; Lu, LinGeng; Lin, XiaoShi; Lu, ShaoYou; Peng, JinLing

    2016-06-01

    Limited literature exists on toxaphene contamination in food worldwide, particularly in mainland China. In this study, three toxaphene congeners, Parlar 26 (B8-1413), Parlar 50 (B9-1679) and Parlar 62 (B9-1025), were analyzed in five different food categories from the Pearl River Delta Area in China using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), and toxaphene levels in food were reported and toxaphene dietary intake by local residents estimated. The results showed that fish contained the highest toxaphene level with a median of 12.87 pg/g wet weight (ww), followed by poultry meat, egg products, livestock meat and vegetable, which had median levels of 5.8, 2.2, 1.89 and 0.67 pg/g ww, respectively. Parlar 50 and Parlar 26 were the predominant characteristic congeners in fish, and Parlar 26 was the predominant congener not only in poultry products and eggs, but also in livestock and vegetable. The estimated average daily intake found by local residents was 35.57 pg/kg body weight/day. Overall toxaphene levels and estimated dietary intake in the Pearl River Delta Area of South China are far lower than the European Maximum Residue Limits (EU MRLs), the German MRL for fish, and other international literature data. Therefore, the risk of adverse health effects from dietary intakes of toxaphene for the local residents is not considerable at the current time, but follow-ups are warranted to study dynamic changes of toxaphene in food in this area. PMID:26991380

  8. Abundances, depositional fluxes, and homologue patterns of polychlorinated biphenyls in dated sediment cores from the Pearl River Delta, China.

    PubMed

    Mai, Bixian; Zeng, Eddy Y; Luo, Xiaojun; Yang, Qingshu; Zhang, Gan; Li, Xiangdong; Sheng, Guoying; Fu, Jiamo

    2005-01-01

    Despite the recent efforts to investigate the distribution and fate of persistent organic pollutants in the tropical and subtropical regions of Asia, very little was known about the temporal change of polychlorinated biphenyls (PCBs) in the environmental ecosystem of China. In this study, three dated sediment cores collected from the Pearl River Delta of southern China were analyzed for a large suite of PCB congeners, from which the temporal profiles of PCB abundances, fluxes, and homologue patterns were constructed. The sedimentary inventories of total PCBs at the sampling sites ranged from 480 to 1310 ng/cm2, at the low end of the worldwide figures. Although production and use of PCBs have been banned or highly restricted in China since the early 1980s, the fluxes of total PCBs continued to increase in the Pearl River Delta sediments. There was a concurrent increase of PCB fluxes and gross domestic product per capita in the region from 1980 to 1997, and a decline of agricultural land use was evident at the same time. Apparently, large-scale land transform since the early 1980s as well as emissions from the PCB-containing electrical equipments were responsible for the sharp rise of PCB fluxes in the recent sediments. The difference in the PCB homologue patterns from 1940 to the mid-1970s was probably indicative of the different timelines of PCB usage in Macao/Hong Kong and mainland China and the differenttypes of technical PCBs commercially used. PCBs were detectable in sediments deposited well before the time frame when production of PCBs began (before 1930) and were relatively enriched in the less chlorinated homologue groups (3Cl and 4Cl PCBs), suggesting the downward mobility of lightly chlorinated PCB congeners in the sediment column. PMID:15667074

  9. Paleogeography of Paleocene Wind River basin

    SciTech Connect

    Flemings, P.B.; Jordan, T.E.

    1986-08-01

    The Paleocene Fort Union Formation in the Wind River basin was deposited in response to Laramide deformation between south-verging faults to the north (Owl Creek and Casper thrusts) and south (Wind River and Granite thrusts). Exposures in this asymmetric basin include a lower fluvial member overlain by the Waltman (lacustrine) and time-equivalent Shotgun (fluvial) members in the northeast and a single fluvial unit in the southeast. In the northeast, low sinuosity, ribbon channel sandstones (northwest paleoflow, about 40 m thick) are overlain by sheet-sand deposits interspersed with channel sandstones (southwest paleoflow, about 700 m thick), which are in turn overlain by the Waltman Member. The basal channel sands are wide (about 100 m perpendicular to flow), thick (5 to 10 m), and trough cross-bedded. The sheet-sand deposits consist of upward-fixing cycles 1 to 10 m thick. These facies are interpreted to be the product of longitudinal drainage flowing parallel to the Casper thrust, overlain by fan-delta sediments prograding perpendicular to the thrust. Palynology suggests a nearly complete Paleocene record for this sequence. To the south along the Rattlesnake Hills, trough cross-bedded sheet sandstones and gravel channel deposits (northward, 140 m thick) are overlain by layered mudstones and siltstones (180 m thick). The top of these high-energy braided-stream deposits and overlying low-energy delta-plain sediments are equivalent in age to the Waltman Member. A topographic low paralleled the Casper arch thrust during the earliest Paleocene. Prograding alluvial-fan sedimentation gradually shifted this topographic low away from the Casper thrust. Southern exposures record drainage toward, and ponding in, the topographic low.

  10. Hydrogeologic framework of sedimentary deposits in six structural basins, Yakima River basin, Washington

    USGS Publications Warehouse

    Jones, M.A.; Vaccaro, J.J.; Watkins, A.M.

    2006-01-01

    The hydrogeologic framework was delineated for the ground-water flow system of the sedimentary deposits in six structural basins in the Yakima River Basin, Washington. The six basins delineated, from north to south are: Roslyn, Kittitas, Selah, Yakima, Toppenish, and Benton. Extent and thicknesses of the hydrogeologic units and total basin sediment thickness were mapped for each basin. Interpretations were based on information from about 4,700 well records using geochemical, geophysical, geologist's or driller's logs, and from the surficial geology and previously constructed maps and well interpretations. The sedimentary deposits were thickest in the Kittitas Basin reaching a depth of greater than 2,000 ft, followed by successively thinner sedimentary deposits in the Selah basin with about 1,900 ft, Yakima Basin with about 1,800 ft, Toppenish Basin with about 1,200 ft, Benton basin with about 870 ft and Roslyn Basin with about 700 ft.

  11. Assessment of microbial dynamics in the Pearl River Estuary by 16S rRNA terminal restriction fragment analysis

    NASA Astrophysics Data System (ADS)

    Wu, Madeline; Song, Liansheng; Ren, Jianping; Kan, Jianjun; Qian, Pei-Yuan

    2004-10-01

    We have evaluated the feasibility of using the terminal restriction fragment length polymorphism (T-RFLP) pattern of polymerase chain reaction (PCR) amplified 16S rRNA sequences to track the changes of the free-living bacterial community for the Pearl River Estuary surface waters. The suitability of specific PCR primers, PCR bias induced by thermal cycles, and field-sampling volumes were critically evaluated in laboratory tests. We established a workable protocol and obtained TRF patterns that reflected the changes in the bacterial population. The temporal dynamics over a 24 h period were examined at one anchored station, as well as the spatial distribution pattern of the bacterial community at several stations, covering the transects along the river discharge direction and across the river plume. The TRF pattern revealed 9 dominant bacterial groups. Changes in their relative abundance reflecting the changes in the bacterial community composition were documented. Many culturable species were isolated from each field sample and a portion of the 16S rRNA gene for each species was sequenced. The species was identified based on sequence data comparison. In this region, the dominant species belong to the γ-subdivision of proteobacteria and the Bacillus/Clostridium group of Firmicutes. We also detected the wide spread distribution of Acinetobacter spp.; many of these species are known nosocomial pathogen for humans.

  12. Polycyclic aromatic hydrocarbons in suspended particulate matter and sediments from the Pearl River Estuary and adjacent coastal areas, China.

    PubMed

    Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian; Yang, Qing-Shu; Sheng, Guo-Ying; Fu, Jia-Mo

    2006-01-01

    The spatial distribution, composition, and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments and suspended particulate matter (SPM) from the Pearl River Estuary and adjacent coastal areas were examined. Total PAH concentrations varied from 189 to 637 ng/g in sediments and 422 to 1,850 ng/g in SPM. PAHs were dominated by 5,6-ring compounds in sediments and by 2,3-ring compounds in SPM samples. Assessment of PAH sources suggested that biomass and coal combustion is the major PAH source to the outer part of the estuary sediments and that petroleum combustion is the major PAH source to the inner part of estuary sediments. As for SPM samples, PAH isomer pair ratios indicated multiple (petroleum, petroleum combustion, and biomass and coal combustion) PAH sources, and significant temporal variations could exist for the sources of water column PAHs in the study area. The distribution of perylene in SPM samples indicated that the river was the dominant source of perylene in SPM and that perylene could be taken as an index to assess the contribution of river inflow to the total PAHs in SPM samples. The high concentration of perylene in the sediment was indicative of an in situ biogenic origin. PMID:15996803

  13. Flexural analysis of two broken foreland basins; Late Cenozoic Bermejo basin and Early Cenozoic Green River basin

    SciTech Connect

    Flemings, P.B.; Jordan, T.E.; Reynolds, S.

    1986-05-01

    Lithospheric flexure that generates basin in a broke foreland setting (e.g., the Laramide foreland of Wyoming) is a three-dimensional system related to shortening along basin-bounding faults. The authors modeled the elastic flexure in three dimensions for two broken foreland basins: the early Cenozoic Green River basin and the analogous late Cenozoic Bermejo basin of Argentina. Each basin is located between a thrust belt and a reverse-fault-bounded basement uplift. Both basins are asymmetric toward the basement uplifts and have a central basement high: the Rock Springs uplift and the Pie de Palo uplift, respectively. The model applies loads generated by crustal thickening to an elastic lithosphere overlying a fluid mantle. Using the loading conditions of the Bermejo basin based on topography, limited drilling, and reflection and earthquake seismology, the model predicts the current Bermejo basin geometry. Similarly, flexure under the loading conditions in the Green River basin, which are constrained by stratigraphy, well logs, and seismic profiling and summed for Late Cretaceous (Lance Formation) through Eocene (Wasatch Formation), successfully models the observed geometry of the pre-Lance surface. Basin depocenters (> 4 km for the Green River basin; > 7 km for the Bermejo basin) and central uplifts are predicted to result from constructive interference of the nonparallel applied loads. Their Bermejo model implies that instantaneous basin geometry is successfully modeled by crustal loading, whereas the Green River basin analysis suggests that basin evolution can be modeled over large time steps (e.g., 20 Ma). This result links instantaneous basin geometry to overall basin evolution and is a first step in predicting stratigraphic development.

  14. Spatial design principles for sustainable hydropower development in river basins

    SciTech Connect

    Jager, Henriëtte I.; Efroymson, Rebecca A.; Opperman, Jeff J.; Kelly, Michael R.

    2015-02-27

    How can dams be arranged within a river basin such that they benefit society? Recent interest in this question has grown in response to the worldwide trend toward developing hydropower as a source of renewable energy in Asia and South America, and the movement toward removing unnecessary dams in the US. Environmental and energy sustainability are important practical concerns, and yet river development has rarely been planned with the goal of providing society with a portfolio of ecosystem services into the future. We organized a review and synthesis of the growing research in sustainable river basin design around four spatial decisions: Is it better to build fewer mainstem dams or more tributary dams? Should dams be clustered or distributed among distant subbasins? Where should dams be placed along a river? At what spatial scale should decisions be made? We came up with the following design principles for increasing ecological sustainability: (i) concentrate dams within a subset of tributary watersheds and avoid downstream mainstems of rivers, (ii) disperse freshwater reserves among the remaining tributary catchments, (iii) ensure that habitat provided between dams will support reproduction and retain offspring, and (iv) formulate spatial decision problems at the scale of large river basins. Based on our review, we discuss trade-offs between hydropower and ecological objectives when planning river basin development. We hope that future testing and refinement of principles extracted from our review will define a path toward sustainable river basin design.

  15. Spatial design principles for sustainable hydropower development in river basins

    DOE PAGESBeta

    Jager, Henriëtte I.; Efroymson, Rebecca A.; Opperman, Jeff J.; Kelly, Michael R.

    2015-02-27

    How can dams be arranged within a river basin such that they benefit society? Recent interest in this question has grown in response to the worldwide trend toward developing hydropower as a source of renewable energy in Asia and South America, and the movement toward removing unnecessary dams in the US. Environmental and energy sustainability are important practical concerns, and yet river development has rarely been planned with the goal of providing society with a portfolio of ecosystem services into the future. We organized a review and synthesis of the growing research in sustainable river basin design around four spatialmore » decisions: Is it better to build fewer mainstem dams or more tributary dams? Should dams be clustered or distributed among distant subbasins? Where should dams be placed along a river? At what spatial scale should decisions be made? We came up with the following design principles for increasing ecological sustainability: (i) concentrate dams within a subset of tributary watersheds and avoid downstream mainstems of rivers, (ii) disperse freshwater reserves among the remaining tributary catchments, (iii) ensure that habitat provided between dams will support reproduction and retain offspring, and (iv) formulate spatial decision problems at the scale of large river basins. Based on our review, we discuss trade-offs between hydropower and ecological objectives when planning river basin development. We hope that future testing and refinement of principles extracted from our review will define a path toward sustainable river basin design.« less

  16. LANDSCAPE ECOLOGY ASSESSMENT OF THE TENSAS RIVER BASIN, MISSISSIPPI RIVER DELTA REGION, AND GULF OF MEXICO

    EPA Science Inventory

    A group of landscape ecological indicators were applied to biophysical data masked to the Tensas River Basin. The indicators were use to identify and prioritize sources of nutrients in a
    Mississippi River System sub-basin. Remotely sensed data were used for change detection a...

  17. UPPER SNAKE RIVER BASIN WATER QUALITY ASSESSMENT, 1976

    EPA Science Inventory

    This package contains information for the Upper Snake River Basin, Idaho (170402, 17040104). The report contains a water quality assessment approach which will assist EPA planners, land agencies, and state and local agencies in identifying probably nonpoint sources and determini...

  18. 15. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN (MODEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN (MODEL SCALE: 1' = 26'). - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  19. 17. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ENGINEERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ENGINEERS EXAMINING MODEL PUMPS, VIEW FROM MODEL BED. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  20. 16. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. MECHANICAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. MECHANICAL AND HYDRAULIC ENGINEERS EXAMINING MODEL PUMPS. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  1. ALTERNATIVE FUTURES FOR THE WILLAMETTE RIVER BASIN, OREGON

    EPA Science Inventory

    Alternative futures analysis is an assessment approach designed to inform community decisions regarding land and water use. We conducted an alternative futures analysis in the Willamette River Basin in western Oregon. Based on detailed input from local stakeholders, three alter...

  2. 19. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ELECTRONICS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ELECTRONICS ENGINEER AT DATA COLLECTION COMPUTER ROOM. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  3. Atmospheric circulation and snowpack in the Gunnison River Basin

    USGS Publications Warehouse

    McCabe, Gregory J.

    1994-01-01

    Winter mean 700-millibar height anomalies over the eastern North Pacific Ocean and the western United States are related to variability in snowpack accumulations measured on or about April 1 in the Gunnison River Basin in Colorado. Higher-than-average snowpack accumulations are associated with negative 700-millibar height anomalies (anomalous cyclonic circulation) over the western United States and over most of the eastern North Pacific Ocean. The anomalous cyclonic circulation enhances the movement of moisture from the eastern North Pacific Ocean into the southwestern United States. Variability in winter mean 700-millibar height anomalies explain over 50 percent of the variability in snowpack accumulations in the Gunnison River Basin. The statistically significant linear relations between 700-millibar height anomalies and snowpack accumulations in the Gunnison River Basin can be used with general-circulation-model simulations of future 700-millibar height anomalies to estimate changes in snowpack accumulations in the Gunnison River Basin for future climatic conditions.

  4. 18. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. CIVIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. CIVIL ENGINEERING AIDE AT CONTROL BOX. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  5. Identification of heavy metal sources in the reclaimed farmland soils of the pearl river estuary in China using a multivariate geostatistical approach.

    PubMed

    Gu, Yang Guang; Li, Qu Sheng; Fang, Jian Hong; He, Bao Yan; Fu, Hong Bo; Tong, Ze Jun

    2014-07-01

    Heavy metals in the reclaimed farmland soils of the Pearl River Estuary in China have attracted much attention because of the health risk posed to local residents. The identification of heavy metal sources in these soils is necessary to reduce their health risk. Reclaimed farmland soil samples were collected from 144 sites in the Pearl River Estuary and the contents of heavy metals (Cd, Pb, Cr, Ni, Cu, and Zn) were determined. All these heavy metals showed concentrations substantially higher than their background values, indicating possible anthropogenic pollution. The results of a multivariate geostatistical method demonstrate that grouped Cd, Cr, and Cu were mainly controlled by chemical fertilizers. Grouped Pb and Zn were the most severely impacted by atmospheric deposition from Guangzhou and Foshan, and Ni was primarily impacted by electroplating factories' wastewater discharge. PMID:24780227

  6. Drainage divides, Massachusetts; Blackstone and Thames River basins

    USGS Publications Warehouse

    Krejmas, Bruce E.; Wandle, S. William

    1982-01-01

    Drainage boundaries for selected subbasins of the Blackstone and Thames River basins in eastern Hampden, eastern Hampshire, western Norfolk, southern Middlesex, and southern Worcester Counties, Massachusetts, are delineated on 12 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 miles on tributary streams or 15 square miles along the Blackstone River, French River, or Quinebaug River. (USGS)

  7. Accessing the Relationship between archaeal and bacterial Tetraethers in the Pearl River Estuary and Coastal South China Sea

    NASA Astrophysics Data System (ADS)

    Wang, J. X.

    2015-12-01

    Microbial intact polar GDGTs with phosphate head groups (phospho IP-GDGTs) are powerful biomarkers for tracing interactions between living cells and their environments. The goal of this study was to examine the relationship between archaeal isoprenoid (iso-) GDGTs and bacterial branched (br-) in the Pearl River estuary and coastal South China Sea. Suspended particulate matter (SPM) was collected using 0.7 μm- and 0.2 μm-filters in winter and summer of 2012. The results exhibited that 1) the abundance of phospho IP-isoGDGTs is lower than phospho IP-brGDGTs in different seasons, and 2) phospho IP-brGDGTs collected from 0.2 μm-filter in winter are significantly higher than the summer. Linear regression analysis showed that the abundance of phospho IP-isoGDGTs and phospho IP-brGDGTs are significantly correlated, suggesting that the source archaea of the isoGDGTs may have functional relationship with the brGDGT-producing bacteria in the study area. Furthermore, the seasonal highest abundances of iso- and br-GDGTs always occurred in the transitional zone between river and estuary, indicating that the transitional area is a highly productive environment for the GDGT-producing organisms.

  8. The 4-D structure of upwelling and Pearl River plume in the northern South China Sea during summer 2008 revealed by a data assimilation model

    NASA Astrophysics Data System (ADS)

    Shu, Yeqiang; Wang, Dongxiao; Zhu, Jiang; Peng, Shiqiu

    We analyze four-dimensional structures of upwelling and Pearl River plume in the northern South China Sea (NSCS) during the summer of 2008 based on data assimilation. An Ensemble Kalman Smoother scheme is employed in the Princeton Ocean Model. It is found that the Pearl River plume axis extended eastward along with the surface current and swerved offshore twice near (116°E, 22.6°N) and (117.5°E, 22.8°N) before reaching the Taiwan Strait. The vertical transect of salinity along the plume axis indicates that the Pearl River freshwater could affect salinity distribution down to a depth of 10-20 m. Anomalously warm water is found in the upper layer, which could be attributed to the intensified stratification and suppressed vertical mixing caused by the freshwater of the plume capping the upwelling west of 116°E. The varying winds from upwelling favorable to downwelling favorable could induce a low-salinity water lens at the center of the model domain. Upwelling in the NSCS initially occurred at 114.5°E, to the east of the Pearl River Estuary, intensified eastward, and reached its maximum near Shantou (116.7°E, 23.2°N). Since current-induced upwelling appeared mainly in Shantou due to the widened shelf, it is found that even if the wind-induced upwelling was shut down in Shanwei by downwelling favorable wind on July 4, the upwelling still existed in Shantou. Moreover, because the direction of large-scale current was in favor of upwelling in the NSCS that cannot be reversed by varying local winds over a short time period, the upwelling shutdown time is longer for both wind-induced and current-induced upwelling in Shantou than for mainly wind-induced upwelling in Shanwei. The steeper slope in Shanwei also shortens the upwelling shutdown time there.

  9. Water resources of Wisconsin, Pecatonica-Sugar River basin

    USGS Publications Warehouse

    Hindall, S.M.; Skinner, Earl L.

    1973-01-01

    The purpose of this report is to describe the physical environment, availability, characteristics, distribution, movement, and quailty of water in the Pecatonica-Sugar River basin.  In addition, water use and water problems are summarized to give an understanding of man's management of water within the basin.

  10. Groundwater issues in the Potomac River Basin

    NASA Astrophysics Data System (ADS)

    Lehr, Jay

    Great strides have been made by the states of Maryland and Pennsylvania, along with the Commonwealth of Virginia and the District of Columbia, in protecting water quality in the Chesapeake Bay and its tributaries. Since these entities joined forces in a renewed effort to protect water quality in the Chesapeake Bay area, a number of useful programs have been established and public awareness has been raised.The Association of Ground Water Scientists and Engineers and several regional co-sponsors presented Ground Water Issues and Solutions in the Potomac River Basin/Chesapeake Bay Region Conference March 14 at George Washington University, Washington, D.C., to provide insight into groundwater-related issues. Attendance at the conference included 150 groundwater professionals from state, county and private agencies, along with a significant number of students from area universities. More than 30 papers were presented dealing with research projects and field studies. Topics included geohydrologic relationships, groundwater quality impacts, impact of industrial processes on groundwater quality, saltwater intrusion, groundwater protection in the Chesapeake Bay area, land-use impacts on groundwater quality, groundwater modeling, groundwater withdrawals, and policy issues. In addition to the technical sessions, a debate of “How clean is clean?” was held.

  11. Greater Green River Basin Production Improvement Project

    SciTech Connect

    DeJarnett, B.B.; Lim, F.H.; Calogero, D.

    1997-10-01

    The Greater Green River Basin (GGRB) of Wyoming has produced abundant oil and gas out of multiple reservoirs for over 60 years, and large quantities of gas remain untapped in tight gas sandstone reservoirs. Even though GGRB production has been established in formations from the Paleozoic to the Tertiary, recent activity has focused on several Cretaceous reservoirs. Two of these formations, the Ahnond and the Frontier Formations, have been classified as tight sands and are prolific producers in the GGRB. The formations typically naturally fractured and have been exploited using conventional well technology. In most cases, hydraulic fracture treatments must be performed when completing these wells to to increase gas production rates to economic levels. The objectives of the GGRB production improvement project were to apply the concept of horizontal and directional drilling to the Second Frontier Formation on the western flank of the Rock Springs Uplift and to compare production improvements by drilling, completing, and testing vertical, horizontal and directionally-drilled wellbores at a common site.

  12. [Heavy metal accumulation during last hundred years and its assessment of potential ecological risk in the coastal wetland of Qi'ao Island, Pearl River Estuary of China].

    PubMed

    Wang, Ai-jun; Ye, Xiang; Li, Tuan-jie; Huang, Cai-bin

    2011-05-01

    The processes of fine sediment transport and deposition can record some relative anthropogenic information in estuarine environments. Grain size analysis of the sediment core collected from coastal wetland of Qi'ao Island in the Pearl River Estuary of China show that the sediment is mainly composed by clayey silt, and the mean grain size, contents of clay and silt increase upward gradually. Chronology analysis show that the sedimentation rate above 59 cm is about 4.15 cm x a(-1), and 0.97 cm x a(-1) beneath 59 cm. Heavy metal analysis indicate that the contents of the each heavy metal increased slowly with a slight intensity of potential ecological risk; however, from 1966 to 1992, the heavy metal contents increased obviously because of the quick social-economy development around the Pearl River Estuary area, and the order of polluting degree of these heavy metals in core sediment is Cd > Ni > Pb > Cu > Cr > Zn. The potential ecological risk intensity of Cd increased from slight risk before 1966 to strong risk since 1992, and the potential ecological risk intensities other heavy metal are slight risk; the potential ecological risk index is weak level. The variations of core sediment heavy metal contents and its ecological risk assessments along the vertical profile reveal the interaction processes and intent of anthropogenic influences from the areas around the Pearl River Estuary and the catchments. PMID:21780584

  13. Part I: Integrated water quality management: river basin approach. Geochemical techniques on contaminated sediments--river basin view.

    PubMed

    Förstner, Ulrich

    2003-01-01

    The big flood in the upper Elbe River catchment area has revealed a wide spectrum of problems with contaminated sediments. So far, an effective strategy for managing contaminated sediments on a river basin scale is still missing and it seems that not much has been learned from the lessons received during the last decade. In the following overview, special emphasis is given to the utilization of geochemically-based techniques for sediment remediation, which can be applied in different parts of a river basin. The examples presented here are mostly from the Elbe River catchment area. In general, new technical problem solutions need a set of practical process knowledge that uses a wide range of simulation techniques, as well as models in different spatial and temporal scales. The evaluation of recent flood events clearly demonstrates the importance of chemical expertise in the decision-making process for the sustainable development in river basins. PMID:12635960

  14. Drainage areas of the Kanawha River basin, West Virginia

    USGS Publications Warehouse

    Mathes, M.V.; Payne, D.D., Jr.; Shultz, R.A.; Kirby, J.R.

    1982-01-01

    Drainage areas for 1,493 drainage area divisions for the Kanawha River basin, West Virginia, are listed in the report. Also tabulated for each site are river miles, plus location identifiers: County, latitude and longitude, and the West Virginia District map number. (USGS)

  15. Drainage areas of the Potomac River basin, West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Hunt, Michelle L.; Stewart, Donald K.

    1996-01-01

    This report contains data for 776 drainage-area divisions of the Potomac River Basin, from the headwaters to the confluence of the Potomac River and the Shenandoah River. Data, compiled in downstream order, are listed for streams with a drainage area of approximately 2 square miles or larger within West Virginia and for U.S. Geological Survey streamflow-gaging stations. The data presented are the stream name, the geographical limits in river miles, the latitude and longitude of the point, the name of the county, and the 7 1/2-minute quadrangle in which the point lies, and the drainage area of that site. The total drainage area of the Potomac River Basin downstream of the confluence of the Shenandoah River at the State boundary is 9,367.29 square miles.

  16. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam...

  17. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam...

  18. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam...

  19. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam...

  20. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam...

  1. Chlorinated paraffins in sediments from the Pearl River Delta, South China: spatial and temporal distributions and implication for processes.

    PubMed

    Chen, Man-Ying; Luo, Xiao-Jun; Zhang, Xiu-Lan; He, Ming-Jing; Chen, She-Jun; Mai, Bi-Xian

    2011-12-01

    Short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) were measured in sediments from ponds, rivers and tributaries, and an estuary, as well as a sediment core in the Pearl River Delta (PRD), South China, to comprehensively investigate the spatial and temporal distributions of CPs. The concentrations of SCCPs and MCCPs in sediment were varied from 320 to 6600 ng/g and from 880 to 38,000 ng/g, respectively. Elevated CP concentrations were found in pond sediments (means of 2800 and 21,000 ng/g for SCCPs and MCCPs) in the e-waste recycling area and in river sediments (means of 1200 and 3900 ng/g for SCCPs and MCCPs) in the highly industrialized areas. The significant positive correlations between SCCP concentration and MCCPs/SCCPs in the highly industrialized areas reflected the emission of local industry activities, while the significant negative correlations in the low industrial activity areas could be linked to long-range transportation of CPs. An increased abundance of short chain and low chlorinated congeners was observed in the low industrial activity areas compared to the industrialized areas. The preferred transportation of short chain and low chlorinated congener CPs and the dechlorination of higher chlorinated congeners CPs were the most likely reasons. The vertical profile of CPs in the sediment core indicated a rapid increase in the usage of CPs and a shift to more MCCPs in recent years. The decreased chlorine content of CPs with increasing sediment depth indicated the possibility of dechlorination of higher chlorinated congeners (Cl(9) and Cl(10)) after deposition in sediments with greater dechlorination potential for short chain CPs than long chain CPs. PMID:22014313

  2. Water loss in the Potomac River basin during droughts

    USGS Publications Warehouse

    Hagen, E.R.; Kiang, J.E.; Dillow, J.J.A.

    2004-01-01

    The water loss phenomena in the Washington DC metropoliton area's (WMA) Potomac River water supply basin during droughts was analyzed. Gage errors, permitted withdrawals, evaporation, and transpiration by trees along the river were investigated to account for loss. The Interstate Commission on the Potomac River Basin (ICPRB) calculated potential gage error and examined permits to determine permitted levels of consumption withdrawals from the Potomac. The result of a single slug test indicated that the soil transmissivity may not be adequate to allow passage of enough water to account for all of the calculated water loss.

  3. Water Allocation Modeling of Awash River Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Asfaw, D. H.; Berhe, F.; Melesse, A. M.

    2012-12-01

    Awash River basin is one of the twelve basins of Ethiopia which is highly utilized and the first basin to be introduced to modern agriculture. A study was conducted on water allocation modeling of Awash River basin, Ethiopia using MODSIM, a river basin management decision support system (DSS) designed as a computer-aided tool for developing improved basin wide planning. This study was conducted to analyze the water balance of the Awash basin under different levels of irrigation development and also determine the water allocation in the Upper, Middle and Lower Valleys in the basin. Awash basin includes Koka Dam and two dams under completion: Kessem and Tendaho Reservoirs. Four scenarios were set: Scenario I-present withdrawal rate in the basin; Scenario II-Scenario I plus Downstream Tendaho Dam Operational; Scenario III-Scenario II plus expansion of middle valley farms and Kessem Dam Operational; and Scenario IV-Scenario III plus additional expansion in the middle valley. Analysis of flow records within the basin was done for a period of 1963-2003. Estimation of system losses, runoff from ungauged tributaries, and Gedebessa Swamp model parameters were considered in the flow process study. Simulation was conducted based on four scenarios. Consumptive and non-consumptive uses were considered in allocation modeling. The results of MODSIM model depict that there will be incremental release from Koka Dam from 2.8% to 5.7% in years 2018 and 2038, respectively. Due to increased diversions in Scenario III when compared to scenario I, losses in to Gedebessa Swamp will significantly decrease by an average of 27.6%. In the year 2038, owing to less capacity of upstream reservoirs due to sedimentation, water will be lost in the swamp complex causing slight decrease of inflow to Tendaho Dam. Additional storage at or upstream of Koka Dam will be mandatory in the future. Unaccounted water diversions upstream of Koka and water losses in Gedebessa Swamp should be considered in the

  4. Water and Benefit Sharing in Transboundary River Basins

    NASA Astrophysics Data System (ADS)

    Arjoon, D.; Tilmant, A.; Herrmann, M.

    2015-12-01

    Growing water scarcity underlies the importance of cooperation for the effective management of river basins, particularly in the context of international rivers in which unidirectional externalities can lead to asymmetric relationships between riparian countries. Studies have shown that significant economic benefits can be expected through basin-wide cooperation, however, the equitable partitioning of these benefits over the basin is less well studied and tends to overlook the importance of stakeholder input in the definition of equitability. In this study, an institutional arrangement to maximize welfare and then share the scarcity cost in a river basin is proposed. A river basin authority plays the role of a bulk water market operator, efficiently allocating bulk water to the users and collecting bulk water charges which are then equitably redistributed among water users. This highly regulated market restrains the behaviour of water users to control externalities and to ensure basin-wide coordination, enhanced efficiency, and the equitable redistribution of the scarcity cost. The institutional arrangement is implemented using the Eastern Nile River basin as a case study. The importance of this arrangement is that it can be adopted for application in negotiations to cooperate in trans-boundary river basins. The benefit sharing solution proposed is more likely to be perceived as equitable because water users help define the sharing rule. As a result, the definition of the sharing rule is not in question, as it would be if existing rules, such as bankruptcy rules or cooperative game theory solutions, are applied, with their inherent definitions of fairness. Results of the case study show that the sharing rule is predictable. Water users can expect to receive between 93.5% and 95% of their uncontested benefits (benefits that they expect to receive if water was not rationed), depending on the hydrologic scenario.

  5. M-Area basin closure, Savannah River Site

    SciTech Connect

    McMullin, S.R.; Horvath, J.G.

    1991-12-31

    M-Area, on the Savannah River Site, processes raw materials and manufactures fuel and target rods for reactor use. Effluent from these processes were discharged into the M-Area settling basin and Lost Lake, a natural wetland. The closure of this basin began in 1988 and included the removal and stabilization of basin fluids, excavation of all contaminated soils from affected areas and Lost Lake, and placement of all materials in the bottom of the emptied basin. These materials were covered with a RCRA style cap, employing redundant barriers of kaolin clay and geosynthetic material. Restoration of excavated uplands and wetlands is currently underway.

  6. M-Area basin closure, Savannah River Site

    SciTech Connect

    McMullin, S.R.; Horvath, J.G.

    1991-01-01

    M-Area, on the Savannah River Site, processes raw materials and manufactures fuel and target rods for reactor use. Effluent from these processes were discharged into the M-Area settling basin and Lost Lake, a natural wetland. The closure of this basin began in 1988 and included the removal and stabilization of basin fluids, excavation of all contaminated soils from affected areas and Lost Lake, and placement of all materials in the bottom of the emptied basin. These materials were covered with a RCRA style cap, employing redundant barriers of kaolin clay and geosynthetic material. Restoration of excavated uplands and wetlands is currently underway.

  7. Implication of drainage basin parameters of a tropical river basin of South India

    NASA Astrophysics Data System (ADS)

    Babu, K. J.; Sreekumar, S.; Aslam, Arish

    2016-03-01

    Drainage morphometry provides quantitative description of the drainage system which is an important aspect of the characterisation of watersheds. Chalakudi River is one of the important rivers of the South India which has attracted attention of many environmental scientists recently because of the proposed Athirapally Hydel Project across the river. SRTM (Shuttle Radar Topographic Mission) data were used for preparing DEM (Digital Elevation Model), Aspect Map and Slope Map. Geographical Information System (GIS) was used for the evaluation of linear, areal and relief aspects of morphometric parameters. The study reveals that the terrain exhibits dentritic and trellis pattern of drainage. The Chalakudi River Basin has a total area of 1,448.73 km2 and is designated as seventh-order basin. The drainage density of the basin is estimated as 2.54 and the lower-order streams mostly dominate the basin. The high basin relief indicates high runoff and sediment transport. The elongation ratio of the Chalakudi Basin is estimated as 0.48 and indicates that the shape of the basin is elongated. The development of stream segments in the basin area is more or less effected by rainfall. Relief ratio indicates that the discharge capability of watershed is very high and the groundwater potential is meagre. The low value of drainage density in spite of mountainous relief indicates that the area is covered by dense vegetation and resistant rocks permeated by fractures and joints. These studies are helpful in watershed development planning and wise utilization of natural resources.

  8. Operational river discharge forecasting in poorly gauged basins: the Kavango River Basin case study

    NASA Astrophysics Data System (ADS)

    Bauer-Gottwein, P.; Jensen, I. H.; Guzinski, R.; Bredtoft, G. K. T.; Hansen, S.; Michailovsky, C. I.

    2014-10-01

    Operational probabilistic forecasts of river discharge are essential for effective water resources management. Many studies have addressed this topic using different approaches ranging from purely statistical black-box approaches to physically-based and distributed modelling schemes employing data assimilation techniques. However, few studies have attempted to develop operational probabilistic forecasting approaches for large and poorly gauged river basins. This study is funded by the European Space Agency under the TIGER-NET project. The objective of TIGER-NET is to develop open-source software tools to support integrated water resources management in Africa and to facilitate the use of satellite earth observation data in water management. We present an operational probabilistic forecasting approach which uses public-domain climate forcing data and a hydrologic-hydrodynamic model which is entirely based on open-source software. Data assimilation techniques are used to inform the forecasts with the latest available observations. Forecasts are produced in real time for lead times of 0 to 7 days. The operational probabilistic forecasts are evaluated using a selection of performance statistics and indicators. The forecasting system delivers competitive forecasts for the Kavango River, which are reliable and sharp. Results indicate that the value of the forecasts is greatest for intermediate lead times between 4 and 7 days.

  9. Policy change driven by an AIS-assisted marine emission inventory in Hong Kong and the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Ng, Simon K. W.; Loh, Christine; Lin, Chubin; Booth, Veronica; Chan, Jimmy W. M.; Yip, Agnes C. K.; Li, Ying; Lau, Alexis K. H.

    2013-09-01

    A new exhaust emission inventory of ocean-going vessels (OGVs) was compiled for Hong Kong by using Automatic Identification System (AIS) data for the first time to determine typical main engine load factors, through vessel speed and operation mode characterization. It was found that in 2007, container vessel was the top emitting vessel type, contributing 9,886, 11,480, 1,173, 521 and 1166 tonnes of SO2, NOx, PM10, VOC and CO, respectively, or about 80%-82% of the emissions. The top five, which also included ocean cruise, oil tanker, conventional cargo vessel and dry bulk carrier, accounted for about 98% of emissions. Emission maps, which add a new spatial dimension to the inventory, show the key emission hot spots in Hong Kong and suggest that a significant portion of emissions were emitted at berth. Scientific evidence about the scale and distribution of ship emissions has contributed in raising public awareness and facilitating stakeholder engagement about the issue. Fair Winds Charter, the world's first industry-led voluntary emissions reduction initiative, is a perfect example of how careful scientific research can be used in public engagement and policy deliberation to help drive voluntary industry actions and then government proposals to control and regulate marine emissions in Hong Kong and the Pearl River Delta region.

  10. Which emission sources are responsible for the volatile organic compounds in the atmosphere of Pearl River Delta?

    PubMed

    Guo, H; Cheng, H R; Ling, Z H; Louie, P K K; Ayoko, G A

    2011-04-15

    A field measurement study of volatile organic compounds (VOCs) was simultaneously carried out in October-December 2007 at an inland Pearl River Delta (PRD) site and a Hong Kong urban site. A receptor model i.e. positive matrix factorization (PMF) was applied to the data for the apportionment of pollution sources in the region. Five and six sources were identified in Hong Kong and the inland PRD region, respectively. The major sources identified in the region were vehicular emissions, solvent use and biomass burning, whereas extra sources found in inland PRD included liquefied petroleum gas and gasoline evaporation. In Hong Kong, the vehicular emissions made the most significant contribution to ambient VOCs (48 ± 4%), followed by solvent use (43 ± 2%) and biomass burning (9 ± 2%). In inland PRD, the largest contributor to ambient VOCs was solvent use (46 ± 1%), and vehicular emissions contributed 26 ± 1% to ambient VOCs. The percentage contribution of vehicular emission in Hong Kong in 2007 is close to that obtained in 2001-2003, whereas in inland PRD the contribution of solvent use to ambient VOCs in 2007 was at the upper range of the results obtained in previous studies and twice the 2006 PRD emission inventory. The findings advance our knowledge of ozone precursors in the PRD region. PMID:21316844

  11. Impacts of aerosols on weather and regional climate over the Pearl River Delta megacity area in China

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Wan, Q.; Meng, W.; Liao, F.; Tan, H.; Zhang, R.

    2011-08-01

    Seven-year measurements of precipitation, lightning flashes, and visibility from 2000 to 2006 have been analyzed in the Pearl River Delta (PRD) region, China, with a focus on the Guangzhou megacity area. Statistical analysis shows that the occurrence of heavy rainfall (>25 mm per day) and frequency of lightning strikes are reversely correlated to visibility during this period. To elucidate the effects of aerosols on cloud processes, precipitation, and lightning activity, a cloud resolving - Weather Research and Forecasting (CR-WRF) model with a two-moment bulk microphysical scheme is employed to simulate a mesoscale convective system occurring on 28 Match 2009 in the Guangzhou megacity area. The model predicted evolutions of composite radar reflectivity and accumulated precipitation are in agreement with measurements from S-band weather radars and automatic gauge stations. The calculated lightning potential index (LPI) exhibits temporal and spatial consistence with lightning flashes recorded by a local lightning detection network. Sensitivity experiments have been performed to reflect aerosol conditions representative of polluted and clean cases. The simulations suggest that precipitation and LPI are enhanced by about 16 % and 50 %, respectively, under the polluted aerosol condition. Our results suggest that elevated aerosol loading suppresses light and moderate precipitation (less than 25 mm per day), but enhances heavy precipitation. The responses of hydrometeors and latent heat release to different aerosol loadings reveal the physical mechanism for the precipitation and lightning enhancement in the Guangzhou megacity area, showing more efficient mixed phase processes and intensified convection under the polluted aerosol condition.

  12. Long-term impacts of aerosols on precipitation and lightning over the Pearl River Delta megacity area in China

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Wan, Q.; Meng, W.; Liao, F.; Tan, H.; Zhang, R.

    2011-12-01

    Seven-year measurements of precipitation, lightning flashes, and visibility from 2000 to 2006 have been analyzed in the Pearl River Delta (PRD) region, China, with a focus on the Guangzhou megacity area. Statistical analysis shows that the occurrence of heavy rainfall (>25 mm per day) and frequency of lightning strikes are reversely correlated to visibility during this period. To elucidate the effects of aerosols on cloud processes, precipitation, and lightning activity, a cloud resolving - Weather Research and Forecasting (CR-WRF) model with a two-moment bulk microphysical scheme is employed to simulate a mesoscale convective system occurring on 28 Match 2009 in the Guangzhou megacity area. The model predicted evolutions of composite radar reflectivity and accumulated precipitation are in agreement with measurements from S-band weather radars and automatic gauge stations. The calculated lightning potential index (LPI) exhibits temporal and spatial consistence with lightning flashes recorded by a local lightning detection network. Sensitivity experiments have been performed to reflect aerosol conditions representative of polluted and clean cases. The simulations suggest that precipitation and LPI are enhanced by about 16% and 50%, respectively, under the polluted aerosol condition. Our results suggest that elevated aerosol loading suppresses light and moderate precipitation (less than 25 mm per day), but enhances heavy precipitation. The responses of hydrometeors and latent heat release to different aerosol loadings reveal the physical mechanism for the precipitation and lightning enhancement in the Guangzhou megacity area, showing more efficient mixed phase processes and intensified convection under the polluted aerosol condition.

  13. Industrial sector-based volatile organic compound (VOC) source profiles measured in manufacturing facilities in the Pearl River Delta, China.

    PubMed

    Zheng, Junyu; Yu, Yufan; Mo, Ziwei; Zhang, Zhou; Wang, Xinming; Yin, Shasha; Peng, Kang; Yang, Yang; Feng, Xiaoqiong; Cai, Huihua

    2013-07-01

    Industrial sector-based VOC source profiles are reported for the Pearl River Delta (PRD) region, China, based source samples (stack emissions and fugitive emissions) analyzed from sources operating under normal conditions. The industrial sectors considered are printing (letterpress, offset and gravure printing processes), wood furniture coating, shoemaking, paint manufacturing and metal surface coating. More than 250 VOC species were detected following US EPA methods TO-14 and TO-15. The results indicated that benzene and toluene were the major species associated with letterpress printing, while ethyl acetate and isopropyl alcohol were the most abundant compounds of other two printing processes. Acetone and 2-butanone were the major species observed in the shoemaking sector. The source profile patterns were found to be similar for the paint manufacturing, wood furniture coating, and metal surface coating sectors, with aromatics being the most abundant group and oxygenated VOCs (OVOCs) as the second largest contributor in the profiles. While OVOCs were one of the most significant VOC groups detected in these five industrial sectors in the PRD region, they have not been reported in most other source profile studies. Such comparisons with other studies show that there are differences in source profiles for different regions or countries, indicating the importance of developing local source profiles. PMID:23584189

  14. Radar-observed diurnal cycle and propagation of convection over the Pearl River Delta during Mei-Yu season

    NASA Astrophysics Data System (ADS)

    Chen, Xingchao; Zhao, Kun; Xue, Ming; Zhou, Bowen; Huang, Xuanxuan; Xu, Weixin

    2015-12-01

    Using operational Doppler radar and regional reanalysis data from 2007-2009, the climatology and physical mechanisms of the diurnal cycle and propagation of convection over the Pearl River Delta (PRD) region of China during the Mei-Yu seasons are investigated. Analyses reveal two hot spots for convection: one along the south coastline of PRD and the other on the windward slope of mountains in the northeastern part of PRD. Overall, convection occurs most frequently during the afternoon over PRD due to solar heating. On the windward slope of the mountains, convection occurrence frequency exhibits two daily peaks, with the primary peak in the afternoon and the secondary peak from midnight to early morning. The nighttime peak is shown to be closely related to the nocturnal acceleration and enhanced lifting on the windward slope of southwesterly boundary layer flow, in the form of boundary layer low-level jet. Along the coastline, nighttime convection is induced by the convergence between the prevailing onshore wind and the thermally induced land breeze in the early morning. Convection on the windward slope of the mountainous area is more or less stationary. Convection initiated near the coastline along the land breeze front tends to propagate inland from early morning to early afternoon when land breeze cedes to sea breeze and the prevailing onshore flow.

  15. Assessment of transboundary environmental effects in the Pearl River Delta Region: Is there a role for strategic environmental assessment?

    SciTech Connect

    Marsden, Simon

    2011-11-15

    China's EIA Law does not require transboundary proposals to be assessed, despite recognition of this globally, for example in the Espoo Convention and Kiev Protocol, and in the European EIA and SEA Directives. In a transboundary context assessment within a state is unusual, as regulating these effects is primarily about the relationship between states. However where a state has more than one legal system such as in the Pearl River Delta (PRD) Region of southern China, transboundary effects should also be addressed. Yet despite the geographical connections between Guangdong Province in mainland China (where the EIA Law applies) and the Hong Kong and Macau Special Administrative Regions (which have their own provisions, neither of which requires transboundary assessments), EIA and SEA are carried out separately. Coordinated or joint approaches to transboundary assessment are generally absent, with the legal autonomy of Hong Kong and Macau a major constraint. As a result institutional responses at the policy level have developed. The article considers global experiences with regulating transboundary EIA and SEA, and analyses potential application to land use, transport and air and water planning in the PRD Region. If applied, benefits may include prevention or mitigation of cumulative effects, broader public participation, and improvements to environmental governance. The PRD Region experience may encourage China to conduct and coordinate EIA and SEA processes with neighbouring states, which has been non-existent or extremely limited to date.

  16. Top-down estimates of benzene and toluene emissions in Pearl River Delta and Hong Kong, China

    NASA Astrophysics Data System (ADS)

    Fang, X.; Shao, M.; Stohl, A.; Zhang, Q.; Zheng, J.; Guo, H.; Wang, C.; Wang, M.; Ou, J.; Thompson, R. L.; Prinn, R. G.

    2015-09-01

    Benzene (C6H6) and toluene (C7H8) are toxic to humans and the environment. They are also important precursors of ground-level ozone and secondary organic aerosols and contribute substantially to severe air pollution in urban areas in China. Discrepancies exist between different bottom-up inventories for benzene and toluene emissions in Pearl River Delta (PRD) and Hong Kong (HK), which are emission hot spots in China. This study provides top-down estimates of benzene and toluene emissions in PRD and HK using atmospheric measurement data from a rural site in the area, Heshan, an atmospheric transport model and an inverse modeling method. The model simulations captured the measured mixing ratios during most pollution episodes. For PRD and HK, the benzene emissions estimated in this study for 2010 were 44 (12-75) Gg yr-1 and 5 (2-7) Gg yr-1 for PRD and HK, respectively, and the toluene emissions were 131 (44-218) Gg yr-1 and 6 (2-9) Gg yr-1, respectively. Temporal and spatial differences between the inversion estimate and four different bottom-up emission estimates are discussed, and it is proposed that more observations at different sites are urgently needed to better constrain benzene and toluene (and other air pollutants) emissions in PRD and HK in the future.

  17. Passive air sampling of DDT, chlordane and HCB in the Pearl River Delta, South China: implications to regional sources.

    PubMed

    Wang, Jun; Guo, Lingli; Li, Jun; Zhang, Gan; Lee, Celine S L; Li, Xiangdong; Jones, Kevin C; Xiang, Yunrong; Zhong, Liuju

    2007-06-01

    The Pearl River Delta (PRD) is one of the largest fast-developing economic zones in China. Hong Kong and the mainland part of the PRD differed in socio-economic development history and chemical management policies. Polyurethane foam (PUF)-passive air sampling (PAS) was deployed at 21 regional air quality monitoring stations across the PRD in summer and winter, respectively. Dichloro-diphenyl-trichloroethane (DDT), chlordane and hexachlorobenzene (HCB) were analyzed with GC-MS. High total DDT (240-3700 pg m(-3)) and chlordane (100-2600 pg m(-3)) concentrations were observed. Concentrations of DDTs and chlordane were higher in summer than winter; HCB vice versa. Spatially, the mainland part of the PRD generally displayed higher DDT concentrations than Hong Kong. Antifouling paint for fishing ships in coastal China was suggested to be an important current DDT source in the coast. The reason is unknown for the very low trans-/cis-chlordane (TC/CC) ratios (0.27) found in the mainland in winter. HCB concentrations were relatively uniform across the PRD, and long range transport of HCB from inland/North China to the PRD in winter was suggested. PMID:17554430

  18. Metabolic and phylogenetic profile of bacterial community in Guishan coastal water (Pearl River Estuary), South China Sea

    NASA Astrophysics Data System (ADS)

    Hu, Xiaojuan; Liu, Qing; Li, Zhuojia; He, Zhili; Gong, Yingxue; Cao, Yucheng; Yang, Yufeng

    2014-10-01

    Characteristics of a microbial community are important as they indicate the status of aquatic ecosystems. In the present study, the metabolic and phylogenetic profile of the bacterioplankton community in Guishan coastal water (Pearl River Estuary), South China Sea, at 12 sites (S1-S12) were explored by community-level physiological profiling (CLPP) with BIOLOG Eco-plate and denaturing gradient gel electrophoresis (DGGE). Our results showed that the core mariculture area (S6, S7 and S8) and the sites associating with human activity and sewage discharge (S11 and S12) had higher microbial metabolic capability and bacterial community diversity than others (S1-5, S9-10). Especially, the diversity index of S11 and S12 calculated from both CLPP and DGGE data ( H>3.2) was higher than that of others as sewage discharge may increase water nitrogen and phosphorus nutrient. The bacterial community structure of S6, S8, S11 and S12 was greatly influenced by total phosphorous, salinity and total nitrogen. Based on DGGE fingerprinting, proteobacteria, especially γ- and α-proteobacteria, were found dominant at all sites. In conclusion, the aquaculture area and wharf had high microbial metabolic capability. The structure and composition of bacterial community were closely related to the level of phosphorus, salinity and nitrogen.

  19. Hotspot of glyoxal over the Pearl River delta seen from the OMI satellite instrument: implications for emissions of aromatic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Miller, Christopher Chan; Jacob, Daniel J.; González Abad, Gonzalo; Chance, Kelly

    2016-04-01

    The Pearl River delta (PRD) is a densely populated hub of industrial activity located in southern China. OMI (Ozone Monitoring Instrument) satellite observations reveal a large hotspot of glyoxal (CHOCHO) over the PRD that is almost twice as large as any other in Asia. Formaldehyde (HCHO) and NO2 observed by OMI are also high in the PRD but no more than in other urban/industrial areas of China. The CHOCHO hotspot over the PRD can be explained by industrial paint and solvent emissions of aromatic volatile organic compounds (VOCs), with toluene being a dominant contributor. By contrast, HCHO in the PRD originates mostly from VOCs emitted by combustion (principally vehicles). By applying a plume transport model to wind-segregated OMI data, we show that the CHOCHO and HCHO enhancements over the PRD observed by OMI are consistent with current VOC emission inventories. Prior work using CHOCHO retrievals from the SCIAMACHY satellite instrument suggested that emission inventories for aromatic VOCs in the PRD were too low by a factor of 10-20; we attribute this result in part to bias in the SCIAMACHY data and in part to underestimated CHOCHO yields from oxidation of aromatics. Our work points to the importance of better understanding CHOCHO yields from the oxidation of aromatics in order to interpret space-based CHOCHO observations in polluted environments.

  20. Top-down estimates of benzene and toluene emissions in the Pearl River Delta and Hong Kong, China

    NASA Astrophysics Data System (ADS)

    Fang, Xuekun; Shao, Min; Stohl, Andreas; Zhang, Qiang; Zheng, Junyu; Guo, Hai; Wang, Chen; Wang, Ming; Ou, Jiamin; Thompson, Rona L.; Prinn, Ronald G.

    2016-03-01

    Benzene (C6H6) and toluene (C7H8) are toxic to humans and the environment. They are also important precursors of ground-level ozone and secondary organic aerosols and contribute substantially to severe air pollution in urban areas in China. Discrepancies exist between different bottom-up inventories for benzene and toluene emissions in the Pearl River Delta (PRD) and Hong Kong (HK), which are emission hot spots in China. This study provides top-down estimates of benzene and toluene emissions in the PRD and HK using atmospheric measurement data from a rural site in the area, Heshan, an atmospheric transport model, and an inverse modeling method. The model simulations captured the measured mixing ratios during most pollution episodes. For the PRD and HK, the benzene emissions estimated in this study for 2010 were 44 (12-75) and 5 (2-7) Gg yr-1 for the PRD and HK, respectively, and the toluene emissions were 131 (44-218) and 6 (2-9) Gg yr-1, respectively. Temporal and spatial differences between the inversion estimate and four different bottom-up emission estimates are discussed, and it is proposed that more observations at different sites are urgently needed to better constrain benzene and toluene (and other air pollutant) emissions in the PRD and HK in the future.

  1. Chloride as tracer of solute transport in the aquifer-aquitard system in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Kuang, Xingxing; Jiao, Jiu Jimmy; Wang, Ya

    2016-02-01

    A 1D numerical model is constructed to investigate the impact of sedimentation and sea level changes on transport of Cl- in the aquifer-aquitard system in the Pearl River Delta (PRD), China. The model simulates the evolution of the vertical Cl- concentration profiles during the Holocene. Sedimentation is modeled as a moving boundary problem. Chloride concentration profiles are reconstructed for nine boreholes, covering a wide area of the PRD, from northwest to southeast. Satisfactory agreement is obtained between simulated and measured Cl- concentration profiles. Diffusion solely is adequate to reproduce the vertical Cl- concentration profiles, which indicates that diffusion is the regionally dominant vertical transport mechanism across the aquitards in the PRD. The estimated effective diffusion coefficients of the aquitards range from 2.0 × 10-11 to 2.0 × 10-10 m2/s. The effective diffusion coefficients of the aquifers range from 3.0 × 10-11 to 4.0 × 10-10 m2/s. Advective transport tends to underestimate Cl- concentrations in the aquitard and overestimate Cl- concentrations in the basal aquifer. The results of this study will help understand the mechanisms of solute transport in the PRD and other deltas with similar geological and hydrogeological characteristics.

  2. Tissue distribution and fate of persistent organic pollutants in Indo-Pacific humpback dolphins from the Pearl River Estuary, China.

    PubMed

    Gui, Duan; Yu, Riqing; He, Xuan; Tu, Qin; Wu, Yuping

    2014-09-15

    Eleven persistent organic pollutant (POP) compounds including ∑PCBs, ∑DDTs, ∑HCHs, aldrin, mirex, endrin, ∑CHLs, dieldrin, HCB, heptachlor and pentachlorobenzene were measured in the kidney, liver, muscle, melon and other tissues of Sousa chinensis stranded on the western coast of the Pearl River Estuary in China during 2007-2013. For most parameters of POPs measured, melon tissues contained the highest mean concentrations with the exception of aldrin, which was higher in the kidney and liver tissues. The concentrations of PCBs, DDTs, heptachlor and endrin in the melon tissue exhibited significant correlations with body length, whereas PCBs and heptachlor also displayed significant regression with age. Our studies showed hepatic concentrations of ∑DDTs, ∑HCHs and mirex in S. chinensis were generally higher than those found in cetaceans from other geographic locations. The high levels of POP residues in the testis of one male dolphin suggested an increasing risk of infertility in the species. PMID:25066456

  3. Impacts of thermal circulations induced by urbanization on ozone formation in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Li, Mengmeng; Song, Yu; Mao, Zhichun; Liu, Mingxu; Huang, Xin

    2016-02-01

    Thermal circulations induced by urbanization could exert important effects on regional ozone (O3) formation through regulating the chemical transformations and transport of O3 and its precursors. In this study, the Weather Research and Forecasting/Chemistry (WRF/Chem) model combined with remote sensing are used to investigate the impacts of urbanization-induced circulations on O3 formation in the Pearl River Delta (PRD) region, China. The urban heat island (UHI) effect in PRD significantly enhances turbulent mixing and modifies local circulations, i.e., initiates the UHI circulation and strengthens the sea breeze, which in turn cause a detectable decrease of daytime O3 concentration (-1.3 ppb) and an increase of O3 (+5.2 ppb) around the nocturnal rush-hours. The suppressed O3 titration destruction due to NOx dilution into the deeper urban boundary layer (200-400 m) is the main reason for elevated nocturnal O3 levels. In the daytime, however, the upward transport of O3 precursors weakens near-surface O3 photochemical production and conversely enhances upper-level O3 generation. Furthermore, the surface UHI convergence flow and intensified sea breeze act to effectively trap O3 at the suburban and coastal regions.

  4. Assessing Long-Term Trend of Particulate Matter Pollution in the Pearl River Delta Region Using Satellite Remote Sensing.

    PubMed

    Li, Ying; Lin, Changqing; Lau, Alexis K H; Liao, Chenghao; Zhang, Yongbo; Zeng, Wutao; Li, Chengcai; Fung, Jimmy C H; Tse, Tim K T

    2015-10-01

    Serious particulate matter (PM) pollution problems in many polluted regions of China have been frequently reported in recent years. Long-term exposure to ambient PM pollution is significantly associated with adverse health effects. Characterizing the long-term trends and variation in PM pollution is a basic requirement for evaluating long-term exposure and for guiding future policies to reduce the effects of air pollution on health. However, long-term, ground-based PM measurements are only available at a few fixed stations. In this study, an algorithm is developed and validated to estimate PM concentrations based on the satellite atmospheric optical depth with 1 km spatial resolution. The long-term trends of PM10 concentrations in the entire Pearl River Delta (PRD) region and different cities are quantified and discussed. From 2001 to 2013, the PM10 pollution of the entire PRD region was dominated by a decreasing trend of -0.15 ± 0.23 μg/m(3)·yr. This decreasing PM10 trend was apparent over 75% of the PRD area, with the most significant decreases observed in the center of the region. However, the remaining 25%, mostly located in the outskirts of the region, showed an increasing PM10 trend. This overall decreasing trend indicates the effectiveness of the control measures applied in the past decade for the primary pollutants. PMID:26302450

  5. Spatial and Vertical Distribution of Dechlorane Plus in Mangrove Sediments of the Pearl River Estuary, South China.

    PubMed

    Sun, Yu-Xin; Zhang, Zai-Wang; Xu, Xiang-Rong; Hao, Qin-Wei; Hu, Yong-Xia; Zheng, Xiao-Bo; Luo, Xiao-Jun; Diao, Zeng-Hui; Mai, Bi-Xian

    2016-10-01

    Thirty surface sediments and three sediment cores were collected from mangrove wetlands in the Pearl River Estuary of South China to investigate the spatial and vertical distribution of Dechlorane Plus (DP). DP concentrations in the mangrove surface sediments ranged from 0.0130 to 1.504 ng/g dry weight (dw). DP concentrations in sediments from Shenzhen were significantly greater than those from Guangzhou and Zhuhai. Anti-Cl11-DP, the dechlorinated product of anti-DP, was also detected in the mangrove sediments with concentrations ranged from not detected to 0.0198 ng/g dw. Significant positive relationship between anti-Cl11-DP and anti-DP levels was observed in the mangrove sediments, suggesting that photo and/or microbial degradation of anti-DP might occur in the sediments. The f anti values in the mangrove sediments were close to those in the technical DP products, suggesting that stereoselective enrichment of anti-DP may not exist in the mangrove sediments. DP concentrations in the mangrove sediment cores generally showed an increasing trend from the bottom to top layers. This is the first study to report the occurrence of DP and its degradation product in the mangrove wetlands. PMID:27421724

  6. Chloride as tracer of solute transport in the aquifer-aquitard system in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Kuang, Xingxing; Jiao, Jiu Jimmy; Wang, Ya

    2016-08-01

    A 1D numerical model is constructed to investigate the impact of sedimentation and sea level changes on transport of Cl- in the aquifer-aquitard system in the Pearl River Delta (PRD), China. The model simulates the evolution of the vertical Cl- concentration profiles during the Holocene. Sedimentation is modeled as a moving boundary problem. Chloride concentration profiles are reconstructed for nine boreholes, covering a wide area of the PRD, from northwest to southeast. Satisfactory agreement is obtained between simulated and measured Cl- concentration profiles. Diffusion solely is adequate to reproduce the vertical Cl- concentration profiles, which indicates that diffusion is the regionally dominant vertical transport mechanism across the aquitards in the PRD. The estimated effective diffusion coefficients of the aquitards range from 2.0 × 10-11 to 2.0 × 10-10 m2/s. The effective diffusion coefficients of the aquifers range from 3.0 × 10-11 to 4.0 × 10-10 m2/s. Advective transport tends to underestimate Cl- concentrations in the aquitard and overestimate Cl- concentrations in the basal aquifer. The results of this study will help understand the mechanisms of solute transport in the PRD and other deltas with similar geological and hydrogeological characteristics.

  7. Modeling study of air pollution due to the manufacture of export goods in China's Pearl River Delta

    SciTech Connect

    David G. Streets; Carolyne Yu; Michael H. Bergin; Xuemei Wang; Gregory R. Carmichael

    2006-04-01

    The Pearl River Delta is a major manufacturing region on the south coast of China that produces more than $100 billion of goods annually for export to North America, Europe, and other parts of Asia. Considerable air pollution is caused by the manufacturing industries themselves and by the power plants, trucks, and ships that support them. It is estimated that 10-40% of emissions of primary SO{sub 2}, NOx, RSP, and VOC in the region are caused by export-related activities. Using the STEM-2K1 atmospheric transport model, it is estimated that these emissions contribute 5-30% of the ambient concentrations of SO{sub 2}, NOx, NOz, and VOC in the region. (NO{sub Z}=PAN, HONO, HNO{sub 3}, N{sub 2}O{sub 5} and organic nitrates). One reason that the exported goods are cheap and therefore attractive to consumers in developed countries is that emission controls are lacking or of low performance. It is estimated that state-of-the-art controls could be installed at an annualized cost of $0.3-3 billion, representing 0.3-3% of the value of the goods produced. Mitigation measures could be adopted without seriously affecting the prices of exported goods and would achieve considerable human health and other benefits in the form of reduced air pollutant concentrations in densely populated urban areas. 22 refs., 5 figs., 5 tabs.

  8. Potential submarine geologic hazards at the entrance of the Pearl River Estuary in the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiqiang; Wei, Zhiqiang; He, Huizhong; Wei, Wei; Qian, Libing; Li, Tuanjie

    2016-08-01

    The potential submarine geologic hazards were distinguished and categorized at the entrance of the Pearl River Estuary in the northern South China Sea, based upon the analysis of side scan sonar and sub-bottom profiler surveying data of about 2500 km long, in an area about 2000 km2 around the Wanshan Archipelago. The data obtained in the survey has the highest spatial resolution by far, which could reveal more detailed distributions and characteristics of the geologic hazards than before. In the study region, three paleo-channels that were buried about 10-30 m below the seabed were found; more than 10 shallow gas areas were discovered. The sand waves found in the region were generally small and located near the islands, and twenty pockmarks found on the seabed were mostly concentrated to north of Zhuzhou island. There are also many man-made obstacles in the region, such as wreckages, pipeline, etc. In this paper we provide a detailed distribution map of the submarine geologic hazards in this region for the first time, and discuss their formation and harmfulness, which will provide a scientific basis for marine engineering construction, marine geologic disaster prevention and mitigation.

  9. Brominated flame retardants in mangrove sediments of the Pearl River Estuary, South China: spatial distribution, temporal trend and mass inventory.

    PubMed

    Zhang, Zai-Wang; Sun, Yu-Xin; Sun, Kai-Feng; Xu, Xiang-Rong; Yu, Shen; Zheng, Tian-Ling; Luo, Xiao-Jun; Tian, Yun; Hu, Yong-Xia; Diao, Zeng-Hui; Mai, Bi-Xian

    2015-03-01

    Sediments were collected from three mangrove wetlands in the Pearl River Estuary (PRE) of South China to investigate spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Concentrations of ΣPBDEs, DBDPE and BTBPE in mangrove sediments of the PRE ranged from 1.25-206, 0.364-34.9, and not detected-0.794 ng g(-1) dry weight, respectively. The highest concentrations of ΣPBDEs, DBDPE and BTBPE were found at the mangrove wetland from Shenzhen, followed by Zhuhai and Guangzhou, showing the dependence on the proximity to urban areas. PBDEs were the predominant brominated flame retardants (BFRs) in mangrove sediments. The concentrations of ΣPBDEs, DBDPE and BTBPE in sediment cores showed an increasing trend from the bottom to top layers, reflecting the increasing usage of these BFRs. The inventories of ΣPBDEs, DBDPE and BTBPE in mangrove sediments were 1962, 245, and 4.10 ng cm(-2), respectively. This is the first study to report the occurrence of DBDPE and BTBPE in mangrove ecosystems. PMID:25482977

  10. Assessment of risk to humans of bisphenol A in marine and freshwater fish from Pearl River Delta, China.

    PubMed

    Wei, Xi; Huang, Yeqing; Wong, Ming H; Giesy, John P; Wong, Chris K C

    2011-09-01

    Bisphenol A (BPA) is a high production-volume chemical used in the manufacture of a wide variety of consumer products. However it is also a ubiquitous contaminant that can interfere with endocrine systems of wildlife and humans. China is the "world factory" and the Pearl River Delta is the major manufacturing center and is consequently polluted. Concentrations of BPA in meats of marketable fish had not been previously reported for this region. In the study upon which we report here concentrations of BPA were determined in 20 common species of freshwater and marine fish, collected from markets in Hong Kong, SAR, China. A comprehensive analytical method based on SPE extraction and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was developed, validated and applied. The method limit of detection (LOD) and limit of quantification (LOQ) were 0.5 and 1.25 ng g(-1) dw, respectively. BPA was detected in 19 species of fish at concentrations, ranging from 0.5 to 2.0 ng g(-1) ww. Average daily BPA intake per person ranged from 1.1×10(2) ng d(-1) for marine fish and 2.2×10(2) ng d(-1) for freshwater fish. Concentrations of BPA in fish from Hong Kong markets unlikely would be causing adverse population-level effects in humans. PMID:21700311

  11. [Prediction and simulation of urban area expansion in Pearl River Delta Region under the RCPs climate scenarios].

    PubMed

    Jiang, Oun-ou; Deng, Xiang-zheng; Ke, Xin-li; Zhao, Chun-hong; Zhang, Wei

    2014-12-01

    The sizes and number of cities in China are increasing rapidly and complicated changes of urban land use system have occurred as the social economy develops rapidly. This study took the urban agglomeration of Pearl River Delta Region as the study area to explore the driving mechanism of dynamic changes of urban area in the urbanization process under the joint influence of natural environment and social economic conditions. Then the CA (cellular automata) model was used to predict and simulate the urban area changes until 2030 under the designed scenarios of planning and RCPs (representative concentration pathways). The results indicated that urbanization was mainly driven by the non-agricultural population growth and social-economic development, and the transportation had played a fundamental role in the whole process, while the areas with high elevation or steep slope restricted the urbanization. Besides, the urban area would keep an expanding trend regardless of the scenarios, however, the expanding speed would slow down with different inflection points under different scenarios. The urban expansion speed increased in the sequence of the planning scenario, MESSAGE scenario and AIM scenario, and that under the MESSAGE climate scenario was more consistent with the current urban development trend. In addition, the urban expansion would mainly concentrate in regions with the relatively high urbanization level, e.g., Guangzhou, Dongguan, Foshan, Shenzhen, Zhanjiang and Chaoshan. PMID:25876417

  12. Assessment of Anthropogenic Impacts in La Plata River Basin

    NASA Astrophysics Data System (ADS)

    Garcia, N. O.; Venencio, M.

    2006-12-01

    An assessment of the variability of the streamflows in La Plata Basin (LPB), particularly in its major tributaries Paraná and Uruguay, is presented in this work. The La Plata Basin, the fifth largest basin in the world and second only to the Amazon in South America, is 3.6 million km2 and covers portions of 5 countries: Argentina, Brazil, Bolivia, Paraguay, and Uruguay. Sub-basins include the Bermejo, Paraná, Paraguay, Pilcomayo, and Uruguay. Major rivers of the basin are the Paraguay, the Uruguay and the Paraná. Streamflows in the LPB have been above normal in the last decades, e.g. the mean flow in the Paraná river during the 1971-1994 period was 34% higher than the mean flow during the 1931-1970 period. A similar analysis carried out on the precipitation records for the La Plata basin showed only a 14% increase during the same periods for the Upper Paraná basin and a 20% increase for the Uruguay basin. In this paper it is postulated that the increase in the streamflows, not explained by precipitation increases, is due to the changes in cultivation patterns in the upper basins of the Paraná and Uruguay. Particularly, the substitution of coffee plantations for annual crops, mainly soybeans, has produced a change in the infiltration patterns that influenced the discharges.

  13. Quantifying the extent of river fragmentation by hydropower dams in the Sarapiqui River Basin, Costa Rica

    USGS Publications Warehouse

    Anderson, Elizabeth P.; Pringle, C.M.; Freeman, Mary C.

    2008-01-01

    1. Costa Rica has recently experienced a rapid proliferation of dams for hydropower on rivers draining its northern Caribbean slope. In the Sarapiqui River Basin, eight hydropower plants were built between 1990 and 1999 and more projects are either under construction or proposed. The majority of these dams are small (< 15 m tall) and operate as water diversion projects. 2. While the potential environmental effects of individual projects are evaluated prior to dam construction, there is a need for consideration of the basin-scale ecological consequences of hydropower development. This study was a first attempt to quantify the extent of river fragmentation by dams in the Sarapiqui River Basin. 3. Using simple spatial analyses, the length of river upstream from dams and the length of de-watered reaches downstream from dams was measured. Results indicated that there are currently 306.8 km of river (9.4% of the network) upstream from eight existing dams in the Sarapiqui River Basin and 30.6 km of rivers (0.9% of the network) with significantly reduced flow downstream from dams. Rivers upstream from dams primarily drain two life zones: Premontane Rain Forest (107.9km) and Lower Montane Rain Forest (168.2km). 4. Simple spatial analyses can be used as a predictive or planning tool for considering the effects of future dams in a basin-scale context. In the Sarapiqui River Basin, we recommend that future dam projects be constructed on already dammed rivers to minimize additional river fragmentation and to protect remaining riverine connectivity.

  14. River stage tomography: A new approach for characterizing groundwater basins

    NASA Astrophysics Data System (ADS)

    Yeh, Tian-Chyi J.; Xiang, Jianwei; Suribhatla, Raghavendra M.; Hsu, Kuo-Chin; Lee, Cheng-Haw; Wen, Jet-Chau

    2009-05-01

    Data from tomographic surveys make an inverse problem better posed in comparison to the data from a single excitation source. A tomographic survey provides different coverages and perspectives of subsurface heterogeneity: nonfully redundant information of the subsurface. Fusion of these pieces of information expands and enhances the capability of a conventional survey, provides cross validation of inverse solutions, and constrains inherently ill posed field-scale inverse problems. Basin-scale tomography requires energy sources of great strengths. Spatially and temporally varying natural stimuli are ideal energy sources for this purpose. In this study, we explore the possibility of using river stage variations for basin-scale subsurface tomographic surveys. Specifically, we use numerical models to simulate groundwater level changes in response to temporal and spatial variations of the river stage in a hypothetical groundwater basin. We then exploit the relation between temporal and spatial variations of well hydrographs and river stage to image subsurface heterogeneity of the basin. Results of the numerical exercises are encouraging and provide insights into the proposed river stage tomography. Using naturally recurrent stimuli such as river stage variations for characterizing groundwater basins could be the future of geohydrology. However, it calls for implementation of sensor networks that provide long-term and spatially distributed monitoring of excitation as well as response signals on the land surface and in the subsurface.

  15. Floods in the Raccoon River basin, Iowa

    USGS Publications Warehouse

    Heinitz, Albert J.

    1980-01-01

    Evaluation of flood hazards, and the planning, design, and operation of various facilities on flood plains requires information on floods. This report provides information on flood stages and discharges, flood magnitude and frequency, bench mark data, and flood profiles for the Raccoon River and some of its tributaries. Ir covers the Raccoon River, the North Raccoon River to the northern boundary of Sac County and the lower reaches of the Middle and South Raccoon Rivers.

  16. Characterizing the temporal variability and emission patterns of pollution plumes in the Pearl River Delta of China

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Poon, C. N.; Kwok, Y. H.; Li, Y. S.

    The Pearl River Delta (PRD) is a fast developing region in China that has experienced serious air pollution such as high ozone (O 3) and poor visibility. In this study, we present the measurement results for ozone, carbon monoxide (CO), nitric oxide (NO), total reactive nitrogen (NO y), and sulfur dioxide (SO 2) obtained at a rural site in the southern PRD during October-December 2001, which is typically a season of high pollution in this region. The aim of this study is to (1) characterize the temporal variability and emission ratios of pollution plumes from the PRD region and (2) elucidate the processes (i.e., sea-land breeze and regional emission) that have contributed to the high concentrations of pollutants over the Pearl Estuary. During the 3-month period, 22 moderately high-ozone episodes (hourly O 3>80 ppbv) were observed, with the highest 1-h O 3 mixing ratio of 142 ppbv. Very high levels of primary pollutants (CO˜3000 ppbv, NO y˜250 ppbv and SO 2˜100 ppbv) were also observed at this rural site. All pollutants tended to show higher mixing ratios in the daytime, which is due to the transport of urban plumes by daytime northerly winds. Cold fronts and northeasterly monsoons were the main synoptic processes that transported regional pollution to the South China coast during autumn and winter. Ozone in the afternoon did not show a simple positive correlation with CO or NO y, as observed in many rural areas, suggesting mixing of air masses of different photochemical ages. The primary pollutants (CO, NO y, and SO 2) exhibited moderately strong positive correlation ( r2=0.55-0.59), with slopes of SO 2/NO y=0.23 ppbv/ppbv and CO/NO y=9.2 ppbv/ppbv. These ratios reflect the combined contributions from Hong Kong and the rest of the PRD region with characteristically different emission signatures. Analysis of individual cases showed that urban Hong Kong plumes typically contained a CO-to-NO y ratio of 3.9-6 ppbv/ppbv, whereas regional air masses usually contained

  17. Feasible optimality of vegetation patterns in river basins

    NASA Astrophysics Data System (ADS)

    Caylor, K. K.; Scanlon, T. M.; Rodriguez-Iturbe, I.

    2004-05-01

    We examine the mechanisms leading to the maintenance of organized vegetation patterns within the network structure of a semiarid New Mexico river basin due to the controlling influence of water stress. A recently formulated analytical framework for the water balance at the daily level is used to link the distribution of climate, soils and vegetation within the basin to patterns growing season water stress. We compare the actual patterns of water stress within the basin to the distribution of water stress that results from vegetation patterns distributed according to two algorithms of local optimization. We demonstrate that a model which maintains local optimization within the network flow path exhibits a better agreement with the patterns of actual basin water stress than a model that allows for neutral local interactions that ignore the network structure of the river basin. These results suggest that the pattern of actual vegetation observed within the basin may correspond to a condition of feasible optimality in which large-scale organization is constrained by the stochastic nature of local interactions mediated by the network configuration. The principles of such organization have important consequences regarding the impact of land cover change on hydrological dynamics in river basins, as well as the geomorphological and biogeographical evolution of landscapes under varying climate and disturbance regimes.

  18. Floods in the English River basin, Iowa

    USGS Publications Warehouse

    Heinitz, A.J.; Riddle, D.E.

    1981-01-01

    Information describing floods is essential for proper planning, design, and operation of bridges and other structures on or over streams and their flood plains. This report provides information on flood stages and discharges, flood magnitude and frequency, bench mark data, and flood profiles for the English River and some of its tributaries. It covers the English River, the North English River to near Guernsey, the south Eaglish River to Barnes City and the lower reaches of the Biddle English and Deep Rivers

  19. Drought in the Klamath River Basin

    NASA Technical Reports Server (NTRS)

    2002-01-01

    For more than 100 years groups in the western United States have fought over water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away from small agricultural communities in the Owen Valley, leaving a dusty dry lake bed. In the late 1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement. Today, farmers are fighting fishermen, environmentalists, and Native American tribes over the water in the Upper Klamath River Basin. A below-average winter snowpack and low rainfall throughout the year have caused an extreme drought in the area along the California/Oregon border. In April 2001 a U.S. District Court stopped water deliveries to farms in the Klamath Irrigation District to preserve adequate water levels in Upper Klamath Lake to protect two endangered species of Mullet fish (called suckers). Water was also reserved for the threatened Coho Salmon which need enough water to swim downstream from their spawning grounds to the ocean. In addition, several Native American tribes have rights to Klamath River water. Further complicating the situation are a handful of wildlife refuges which usually receive enough irrigation wastewater to support upwards of a million migratory birds and 900 Bald Eagles. This year, however, several of the refuges may not have enough water for the birds which begin arriving in early fall. The severity of this year's drought is underscored by the town of Bonanza, Oregon. Famous for its natural springs, and entirely dependent on wells for drinking water, the town's water supply is now contaminated with pesticides, fertilizer, and manure. The water quality is so bad it's not even safe to bathe in, much less drink. The problem stems from a very low water table. The drop in underground water levels is caused directly by the drought, and indirectly from the increased irrigation from underground

  20. Drought in the Klamath River Basin

    NASA Technical Reports Server (NTRS)

    2002-01-01

    For more than 100 years groups in the western United States have fought over water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away from small agricultural communities in the Owen Valley, leaving a dusty dry lake bed. In the late 1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement. Today, farmers are fighting fishermen, environmentalists, and Native American tribes over the water in the Upper Klamath River Basin. A below-average winter snowpack and low rainfall throughout the year have caused an extreme drought in the area along the California/Oregon border. In April 2001 a U.S. District Court stopped water deliveries to farms in the Klamath Irrigation District to preserve adequate water levels in Upper Klamath Lake to protect two endangered species of Mullet fish (called suckers). Water was also reserved for the threatened Coho Salmon which need enough water to swim downstream from their spawning grounds to the ocean. In addition, several Native American tribes have rights to Klamath River water. Further complicating the situation are a handful of wildlife refuges which usually receive enough irrigation wastewater to support upwards of a million migratory birds and 900 Bald Eagles. This year, however, several of the refuges may not have enough water for the birds which begin arriving in early fall. The severity of this year's drought is underscored by the town of Bonanza, Oregon. Famous for its natural springs, and entirely dependent on wells for drinking water, the town's water supply is now contaminated with pesticides, fertilizer, and manure. The water quality is so bad it's not even safe to bathe in, much less drink. The problem stems from a very low water table. The drop in underground water levels is caused directly by the drought, and indirectly from the increased irrigation from underground

  1. Persistent halogenated compounds in fish from rivers in the Pearl River Delta, South China: Geographical pattern and implications for anthropogenic effects on the environment.

    PubMed

    Sun, Runxia; Luo, Xiaojun; Tang, Bin; Li, Zongrui; Wang, Tao; Tao, Lin; Mai, Bixian

    2016-04-01

    Three fish species, mud carp (Cirrhinus molitorella), tilapia (Tilapia nilotica), and plecostomus (Hypostomus plecostomus), from rivers in the Pearl River Delta (PRD) were analyzed for dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), and Dechlorane Plus (DP). The concentrations of DDTs, HCHs, PCBs, PBDEs, DBDPE, and DP ranged from 380-57,000, 5.5-100, 30-4200, 6.9-690, 0.29-460, and 0.09-20ng/g lipid weight, respectively. Congener profiles or chemical compositions of PBDEs, DPs, DDTs, and HCHs in plecostomus differed significantly from those in the other two fish species, which can be ascribed to species-specific metabolism. DDTs derived from historical residue and land erosion remained the predominant pollutants in the PRD, while industrial and urban activities resulted in elevated levels of PCBs and PBDEs in the metropolitan area. E-waste recycling activities have greatly impacted on the adjacent aquatic environment, and the potential point source for DBDPE was also revealed. PMID:26821261

  2. Resolving the scale incompatibility dilemma in river basin management

    NASA Astrophysics Data System (ADS)

    Perry, Jim; Easter, K. William

    2004-08-01

    This study illustrates how integrated river basin management can conflict with our increased emphasis on decentralizing water resources decision making. For over a decade, water and environmental decision making in many countries has been shifting from national levels to state/province and local levels. At the same time we have increasingly found that it is critical to consider how individual water resource decisions impact the river basin. We provide detailed examples of this incompatibility dilemma from the United States and Turkey as well as smaller examples from Japan and Macedonia. We argue that new institutional models are required for effective river basin management and that implementation of such models can be evaluated through the use of transaction costs. This study concludes with examples of institutional arrangements that can help bridge the incompatibility gap.

  3. Challenges of river basin management: Current status of, and prospects for, the River Danube from a river engineering perspective.

    PubMed

    Habersack, Helmut; Hein, Thomas; Stanica, Adrian; Liska, Igor; Mair, Raimund; Jäger, Elisabeth; Hauer, Christoph; Bradley, Chris

    2016-02-01

    In the Danube River Basin multiple pressures affect the river system as a consequence of river engineering works, altering both the river hydrodynamics and morphodynamics. The main objective of this paper is to identify the effects of hydropower development, flood protection and engineering works for navigation on the Danube and to examine specific impacts of these developments on sediment transport and river morphology. Whereas impoundments are characterised by deposition and an excess of sediment with remobilisation of fine sediments during severe floods, the remaining five free flowing sections of the Danube are experiencing river bed erosion of the order of several centimetres per year. Besides the effect of interruption of the sediment continuum, river bed degradation is caused by an increase in the sediment transport capacity following an increase in slope, a reduction of river bed width due to canalisation, prohibition of bank erosion by riprap or regressive erosion following base level lowering by flood protection measures and sediment dredging. As a consequence, the groundwater table is lowered, side-arms are disconnected, instream structures are lost and habitat quality deteriorates affecting the ecological status of valuable floodplains. The lack of sediments, together with cutting off meanders, leads also to erosion of the bed of main arms in the Danube Delta and coastal erosion. This paper details the causes and effects of river engineering measures and hydromorphological changes for the Danube. It highlights the importance of adopting a basin-wide holistic approach to river management and demonstrates that past management in the basin has been characterised by a lack of integration. To-date insufficient attention has been paid to the wide-ranging impacts of river engineering works throughout the basin: from the basin headwaters to the Danube Delta, on the Black Sea coast. This highlights the importance of new initiatives that seek to advance knowledge

  4. Backwater effects in the Amazon River basin of Brazil

    USGS Publications Warehouse

    Meade, R.H.; Rayol, J.M.; Da Conceicao, S.C.; Natividade, J.R.G.

    1991-01-01

    The Amazon River mainstem of Brazil is so regulated by differences in the timing of tributary inputs and by seasonal storage of water on floodplains that maximum discharges exceed minimum discharges by a factor of only 3. Large tributaries that drain the southern Amazon River basin reach their peak discharges two months earlier than does the mainstem. The resulting backwater in the lowermost 800 km of two large southern tributaries, the Madeira and Puru??s rivers, causes falling river stages to be as much as 2-3 m higher than rising stages at any given discharge. Large tributaries that drain the northernmost Amazon River basin reach their annual minimum discharges three to four months later than does the mainstem. In the lowermost 300-400 km of the Negro River, the largest northern tributary and the fifth largest river in the world, the lowest stages of the year correspond to those of the Amazon River mainstem rather than to those in the upstream reaches of the Negro River. ?? 1991 Springer-Verlag New York Inc.

  5. Dynamic water accounting in heavily committed river basins

    NASA Astrophysics Data System (ADS)

    Tilmant, Amaury; Marques, Guilherme

    2014-05-01

    Many river basins throughout the world are increasingly under pressure as water demands keep rising due to population growth, industrialization, urbanization and rising living standards. In the past, the typical answer to meet those demands focused on the supply-side and involved the construction of hydraulic infrastructures to capture more water from surface water bodies and from aquifers. As river basins were being more and more developed, downstream water users and ecosystems have become increasingly dependant on the management actions taken by upstream users. The increased interconnectedness between water users, aquatic ecosystems and the built environment is further compounded by climate change and its impact on the water cycle. Those pressures mean that it has become increasingly important to measure and account for changes in water fluxes and their corresponding economic value as they progress throughout the river system. Such basin water accounting should provide policy makers with important information regarding the relative contribution of each water user, infrastructure and management decision to the overall economic value of the river basin. This paper presents a dynamic water accounting approach whereby the entire river basin is considered as a value chain with multiple services including production and storage. Water users and reservoirs operators are considered as economic agents who can exchange water with their hydraulic neighbors at a price corresponding to the marginal value of water. Effective water accounting is made possible by keeping track of all water fluxes and their corresponding transactions using the results of a hydro-economic model. The proposed approach is illustrated with the Eastern Nile River basin in Africa.

  6. Transport of diazinon in the San Joaquin River Basin, California

    USGS Publications Warehouse

    Kratzer, C.R.

    1999-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood-boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water in February 1993. Previous studies focused mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River - the Merced, Tuolumne, and Stanislaus rivers - and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated travel times, ephemeral west-side creeks probably were the main diazinon source early in the storms, whereas the Tuolumne and Merced rivers and east-side drainages directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 1991-1993 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 ??g/L, a concentration shown to be acutely toxic to water fleas. On the basis of this study and previous studies, diazinon concentrations and streamflow are highly variable during January and February storms, and frequent sampling is required to evaluate transport in the San Joaquin River Basin.

  7. Impact of GRACE signal leakage over the Congo River Basin

    NASA Astrophysics Data System (ADS)

    Lee, H.; Beighley, R. E.; Duan, J.; Shum, C.; Alsdorf, D. E.; Andreadis, K.

    2013-05-01

    The Congo Basin is the world's third largest in size, and second only to the Amazon River in discharge. The impact and connections of this hydrologic flux with the region's climate, biogeochemical cycling, and terrestrial water storage (TWS), especially in wetlands, is clearly of great importance. Yet, there is a great lack of published research documenting the Congo Basin terrestrial water balance. This lack of research is related in part to the limited amount of in-situ data; however, the abundance of spaceborne data suggests an opportunity for discovery. The Congo River is the only major river to cross the equator twice. In doing so, the basin lies in both the Northern and Southern Hemisphere such that it receives year-round rainfall from the migration of Inter-Tropical Convergence Zone (ITCZ). After the north has its wet season in the spring and summer, the ITCZ moves south and the remainder of the basin receives large amounts of rain. Consequently, the movement of ITCZ can also be observed from the Gravity Recovery and Climate Experiment (GRACE) TWS changes over the northern and southern boundaries over the Congo. This spatial pattern of the TWS variations are different from that over the Amazon Basin, where the strongest positive or negative annual water storage anomalies are observed to be centered inside the basin. In this study, we examine individual monthly geographical distribution of GRACE TWS changes from various RL05 products, and determine the leakage-contaminated monthly solutions by comparison with reproduced TWS variations from Hillslope River Routing (HRR) model in sub-basin scale. We also present a methodology to empirically remove the signal leakage, and consequently improve the GRACE TWS estimates over the entire Congo Basin.

  8. Drainage areas of the Guyandotte River basin, West Virginia

    USGS Publications Warehouse

    Mathes, M.V.

    1977-01-01

    This report, prepared in cooperation with the West Virginia Office of Federal-State Relations (now the Office of Economic and Community Development), lists in tabular form 435 drainage areas for basins within the Guyandotte River basin of West Virginia. Drainage areas are compiled for sites at the mouths of all streams having drainage areas of approximately five square miles or greater, for sites at U.S. Geological Survey gaging stations (past and present), and for other miscellaneous sites. (Woodard-USGS)

  9. Mid-Holocene variability of the East Asian monsoon based on bulk organic δ13C and C/N records from the Pearl River estuary, southern China

    NASA Astrophysics Data System (ADS)

    Yu, F.; Lloyd, J. M.; Zong, Y.; Leng, M. J.; Switzer, A. D.; Yim, W. W.; Huang, G.

    2010-12-01

    Understanding the mid-Holocene dynamics of the East Asian monsoon (EAM) is integral to modelling the Holocene development of the global climate system (Webster et al., 1998). Thus the mid-Holocene EAM history was reconstructed using bulk organic carbon isotopes (δ13C), total carbon to total nitrogen (C/N) ratios and total organic carbon (TOC) from a sediment core (UV1), at a mean resolution of 10 years, from the Pearl River estuary, southern China. Sedimentary δ13C, C/N and TOC from the Pearl River estuary is a good indicator of changes in monsoonal precipitation strength (Zong et al., 2006; Yang et al., 2010), eg sediments buried during a period of high precipitation exhibit a high proportion of terrigenous sediments, and have low δ13C and high C/N, and vice versa (Yu et al., 2010). Results suggest a general decreasing trend in monsoonal precipitation from 6650-2215 cal yr BP due to the weakening insolation over northern hemisphere most likely related to the current precession circle (An, 2000). Superimposed on this trend are apparent dry-wet oscillations at centennial to millennial timescales most likely in response to solar activity. Mismatch between δ13C and results from the Dongge Cave in southern China at millennial-timescale oscillations (Wang et al., 2005), may indicate that the δ13C from the Pearl River estuary reveals changes in precipitation in a broader area than the δ18O from Dongge Cave does. Reference An Z (2000) The history and variability of the East Asian paleomonsoon climate. Quaternary Science Reviews 19: 171-187. Wang Y, Cheng H, Edwards RL, He Y, Kong X, An Z, Wu J, Kelly MJ, Dykoski CA and Li X (2005) The Holocene Asian Monsoon: Links to Solar Changes and North Atlantic Climate. Science 308: 854-857. Webster PJ, Magaña VO, Palmer TN, Shukla J and Tomas RA (1998) Monsoons: Processes, predictability, and the prospects for prediction. Journal of Geophysical Research 103(C7): 14451-14510. Yang S, Tang M, Yim WWS, Zong Y, Huang G, Switzer

  10. Mid-Holocene variability of the East Asian monsoon based on bulk organic δ13C and C/N records from the Pearl River estuary, southern China

    NASA Astrophysics Data System (ADS)

    Yu, F.; Zong, Y.; Lloyd, J. M.; Leng, M. J.; Switzer, A. D.; Yim, W. W.; Huang, G.

    2012-12-01

    Understanding the mid-Holocene dynamics of the East Asian monsoon (EAM) is integral to modelling the Holocene development of the global climate system (Webster et al., 1998). Thus the mid-Holocene EAM history was reconstructed using bulk organic carbon isotopes (δ13C), total carbon to total nitrogen (C/N) ratios and total organic carbon (TOC) from a sediment core (UV1), at a mean resolution of 7-10 years, from the Pearl River estuary, southern China. Sedimentary δ13C, C/N and TOC from the Pearl River estuary is a good indicator of changes in monsoonal precipitation strength (Zong et al., 2006; Yang et al., 2010; Yu et al., 2010), eg sediments buried during a period of high precipitation exhibit a high proportion of terrigenous sediments, and have low δ13C and high C/N, and vice versa (Yu et al., 2010). Results suggest a general decreasing trend in monsoonal precipitation from 6650 to 2215 cal yr BP because of the weakening Northern Hemisphere insolation most likely related to the current precession circle (An, 2000). Superimposed on this trend are apparent dry-wet oscillations at centennial to millennial timescales most likely in response to solar activity. Mismatch between δ13C and results from the Dongge Cave in southern China at millennial-timescale oscillations (Wang et al., 2005), may indicate that the δ13C from the Pearl River estuary reveals changes in precipitation in a broader area than the δ18O from Dongge Cave does. Reference An Z (2000) The history and variability of the East Asian paleomonsoon climate. Quaternary Science Reviews 19: 171-187. Wang Y, Cheng H, Edwards RL, He Y, Kong X, An Z, Wu J, Kelly MJ, Dykoski CA and Li X (2005) The Holocene Asian Monsoon: Links to Solar Changes and North Atlantic Climate. Science 308: 854-857. Webster PJ, Magaña VO, Palmer TN, Shukla J and Tomas RA (1998) Monsoons: Processes, predictability, and the prospects for prediction. Journal of Geophysical Research 103(C7): 14451-14510. Yang S, Tang M, Yim WWS, Zong

  11. Drainage divides, Massachusetts; Westfield and Farmington River basins

    USGS Publications Warehouse

    Gadoury, Russell A.; Wandle, S. William, Jr.

    1983-01-01

    Drainage boundaries for selected subbasins in western Hampshire, western Hampden, and southeastern Berkshire Counties, Massachusetts, are delineated on 15 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 square miles on tributary streams or 10 square miles along the Westfield or Farmington Rivers. (USGS)

  12. Sediment Transport in Streams in the Umpqua River Basin, Oregon

    USGS Publications Warehouse

    Onions, C. A.

    1969-01-01

    This report presents tables of suspended-sediment data collected from 1956 to 1967 at 10 sites in the Umpqua River basin. Computations based on these data indicate that average annual suspended-sediment yields at these sites range from 137 to 822 tons per square mile. Because available data for the Umpqua River basin are generally inadequate for accurate determinations of sediment yield and for the definition of characteristics of fluvial sediments, recommendations are made for the collection and analysis of additional sediment data.

  13. N Budgets of the Piracicaba River Basin, Southeast Brazil

    NASA Astrophysics Data System (ADS)

    Filoso, S.; Williams, M.; Martinelli, L.

    2001-05-01

    Nitrogen budgets and the importance of the principal types of land use and other human activities as sources and sinks of N were determined for a meso-scale river basin (12 400 km2) in one of the most developed and economically important regions of South America. The Piracicaba River basin is located in southeastern Brazil and drains into a tributary of the Parana River. The basin supports about 2% of the population of Brazil with intensive agricultural and industrial activities. During two years from 1995 to 1997, biweekly samples were collected at 10 points along the Piracicaba River and its tributaries for analyses of dissolved and particulate N. The annual flux of N increased by a factor of about 20 times from the headwaters to the lower reaches of the main channel. Mass balances calculated for six linked sectors of the river system and for the entire basin had inputs that were generally slightly lower than outputs. These results are different from those observed in temperate regions, where low outputs in relation to inputs are common.

  14. Regionalization of flood hydrograph parameters in the Kolubara River Basin

    NASA Astrophysics Data System (ADS)

    Drobnjak, Aleksandar; Zlatanovic, Nikola; Bozovic, Nikola; Stojkovic, Milan; Orlic Momcilovic, Aleksandra; Jelovac, Milena; Prohaska, Stevan

    2016-04-01

    The Kolubara River basin is located in the western part of Serbia. There are several hydrological and rainfall gauging stations in the basin, while a large part of the basin is ungauged. In recent years in this area floods have been a common occurrence, so it is necessary to improve the system of flood protection. The research that is presented in this study represents a hydrological aspect to strengthening flood protection. This study presents the procedure of regionalization of basic flood hydrograph parameters in the Kolubara river basin. All significant observed flood waves in the basin over the past 50 years were collected, assimilated and analyzed. In this research, the method applied was based on the separation of flood hydrograph parameters, for each hydrological station: time to peak (time from the beginning of the hydrograph to its peak) (Tp), time of recession (time from the peak to the end of the recession limb) (Tr), retention time of rainfall in the catchment (tp) and time of concentration (Tc). Using these parameters and morphological characteristics of the basin, such as catchment area, the distance weighted channel slope, length of the main stream, the distance of the center of basin to the profile of each hydrological stations, regional dependencies were established. Parameters of flood hydrograph were analyzed as dependent variables, while the morphological characteristics of the basin represent independent variables. The final goal of this work is to use the obtained regional dependence for flood hydrograph parameter estimation at ungauged locations, with the end goal of improving flood protection in the Kolubara river basin.

  15. Selected streamflow data for the Delaware River basin

    USGS Publications Warehouse

    Schopp, Robert D.; Gillespie, Brian D.

    1979-01-01

    Selected streamflow data for the Delaware River basin include runoff-precipitation relationships for 28 selected subbasins for the period 1941-70; low-flow frequency curves for four mainstem Delaware River sites; monthly comparative duration curves and twenty year hydrographs at Montague and Trenton, New Jersey; and flow duration tables based on observed daily streamflow for gaging stations near 21 proposed dam sites. (Woodard-USGS)

  16. Nitrogen Removal by Streams and Rivers of the Upper Mississippi River Basin

    EPA Science Inventory

    Our study, based on chemistry and channel dimensions data collected at 893 randomly-selected stream and river sites in the Mississippi River basin, demonstrated the interaction of stream chemistry, stream size, and NO3-N uptake metrics across a range of stream sizes and across re...

  17. Floods of December 1982 to May 1983 in the central and southern Mississippi River and the Gulf of Mexico basins

    USGS Publications Warehouse

    Stone, Roy B.; Bingham, Roy H.

    1991-01-01

    Widespread flooding occurred in December 1982 and in spring 1983 in the central and southern Mississippi River basin. The first series of storms, December 2-7, caused severe flooding along many streams in Illinois, Missouri, and Arkansas. Much of the three-State area experienced recordbreaking 24-hour rainfall amounts that caused some streams to exceed previously known flood heights and discharges; in many cases the recurrence interval of peak discharges exceeded 100 years. The second series of storms, December 24-29, caused severe flooding in Louisiana and moderate flooding in Mississippi. Peak discharges on some streams exceeded the 100-year recurrence interval. Damages exceeded $200 million and 25 persons died as a result of the December storms. Western Tennessee was on the fringes of both storms and received only minor flooding. During April 4-8, 1983, as much as 17 inches of rain fell in parts of southern Mississippi and southeastern Louisiana. In some areas, 24-hour amounts exceeded 5 inches, causing peak discharges to exceed the recurrence interval of 100 years at 20 streamflow gaging stations. In May 1983 heavy and intense rains caused major flooding in the Big Black River and Pearl River basins in Mississippi.

  18. An environmental streamflow assessment for the Santiam River basin, Oregon

    USGS Publications Warehouse

    Risley, John C.; Wallick, J. Rose; Mangano, Joseph F.; Jones, Krista L.

    2012-01-01

    The Santiam River is a tributary of the Willamette River in northwestern Oregon and drains an area of 1,810 square miles. The U.S. Army Corps of Engineers (USACE) operates four dams in the basin, which are used primarily for flood control, hydropower production, recreation, and water-quality improvement. The Detroit and Big Cliff Dams were constructed in 1953 on the North Santiam River. The Green Peter and Foster Dams were completed in 1967 on the South Santiam River. The impacts of the structures have included a decrease in the frequency and magnitude of floods and an increase in low flows. For three North Santiam River reaches, the median of annual 1-day maximum streamflows decreased 42–50 percent because of regulated streamflow conditions. Likewise, for three reaches in the South Santiam River basin, the median of annual 1-day maximum streamflows decreased 39–52 percent because of regulation. In contrast to their effect on high flows, the dams increased low flows. The median of annual 7-day minimum flows in six of the seven study reaches increased under regulated streamflow conditions between 60 and 334 percent. On a seasonal basis, median monthly streamflows decreased from February to May and increased from September to January in all the reaches. However, the magnitude of these impacts usually decreased farther downstream from dams because of cumulative inflow from unregulated tributaries and groundwater entering the North, South, and main-stem Santiam Rivers below the dams. A Wilcox rank-sum test of monthly precipitation data from Salem, Oregon, and Waterloo, Oregon, found no significant difference between the pre-and post-dam periods, which suggests that the construction and operation of the dams since the 1950s and 1960s are a primary cause of alterations to the Santiam River basin streamflow regime. In addition to the streamflow analysis, this report provides a geomorphic characterization of the Santiam River basin and the associated conceptual

  19. Grande Ronde Basin Supplementation Program; Lostine River, 2000 Annual Report.

    SciTech Connect

    Onjukka, Sam T.; Harbeck, Jim

    2003-03-01

    The Northwest Power Planning Council (NPPC) identified supplementation as a high priority to achieve its goal of increasing runs of anadromous fish in the Columbia Basin. Supplementation activities in the Lostine River and associated monitoring and evaluation conducted by the Nez Perce Tribe relate directly to the needs addressed in the Columbia River Basin Fish and Wildlife Program (NPPC 1994). Measure 7.4L.1 of the Program mandates that appropriate research accompany any proposed supplementation. In addition, measure 7.3B.2 of the Program stresses the need for evaluating supplementation projects to assess their ability to increase production. Finally, Section 7.4D.3 encourages the study of hatchery rearing and release strategies to improve survival and adaptation of cultured fish. In 1997, Oregon Department of Fisheries and Wildlife (ODFW) requested a modification of Permit 1011 to allow the take of adult spring chinook salmon. In 1998, the Nez Perce Tribe also requested a permit specific to activities on Lostine River. The permit was issued in 2000. A special condition in the permits required the development of a long term management plan for the spring chinook salmon of the Grande Ronde Basin. The Nez Perce Tribe, ODFW, and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) completed a formal long range plan entitled ''Grande Ronde Basin Endemic Spring Chinook Salmon Supplementation Program''. The program proposes to increase the survival of spring chinook salmon in the Grand Ronde Basin through hatchery intervention. Adult salmon from the Lostine River, Catherine Creek, and the Upper Grande Ronde River are used for a conventional supplementation program in the basin. The Nez Perce program currently operates under the ESA Section 10 Permit 1149.

  20. Grande Ronde Basin Supplementation Program; Lostine River, 2001 Annual Report.

    SciTech Connect

    Onjukka, Sam T.; Harbeck, Jim

    2003-03-01

    The Northwest Power Planning Council (NPPC) identified supplementation as a high priority to achieve its goal of increasing runs of anadromous fish in the Columbia Basin. Supplementation activities in the Lostine River and associated monitoring and evaluation conducted by the Nez Perce Tribe relate directly to the needs addressed in the Columbia River Basin Fish and Wildlife Program (NPPC 1994). Measure 7.4L.1 of the Program mandates that appropriate research accompany any proposed supplementation. In addition, measure 7.3B.2 of the Program stresses the need for evaluating supplementation projects to assess their ability to increase production. Finally, Section 7.4D.3 encourages the study of hatchery rearing and release strategies to improve survival and adaptation of cultured fish. In 1997, Oregon Department of Fisheries and Wildlife (ODFW) requested a modification of Permit 1011 to allow the take of adult spring chinook salmon. In 1998, the Nez Perce Tribe also requested a permit specific to activities on Lostine River. The permit was issued in 2000. A special condition in the permits required the development of a long term management plan for the spring chinook salmon of the Grande Ronde Basin. The Nez Perce Tribe, ODFW, and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) completed a formal long range plan entitled ''Grande Ronde Basin Endemic Spring Chinook Salmon Supplementation Program''. The program proposes to increase the survival of spring chinook salmon in the Grand Ronde Basin through hatchery intervention. Adult salmon from the Lostine River, Catherine Creek, and the Upper Grande Ronde River are used for a conventional supplementation program in the basin. The Nez Perce program currently operates under the ESA Section 10 Permit 1149.

  1. Effects of livestock wastes on small illinois streams: Lower Kaskaskia river basin and upper little wabash river basins, summer 1991

    SciTech Connect

    Hite, R.L.; Bickers, C.A.; King, M.M.; Brockamp, D.W.

    1992-07-01

    In early 1991, the Illinois Environmental Protection Agency (IEPA) initiated an investigation to evaluate livestock waste runoff in southern Illinois. The primary objectives of this survey were to document stream quality impairments caused by livestock waste runoff, and ultimately, the need for better waste management practices, waste management systems, and funding for such systems. Information provided by Soil Conservation Service (SCS) and IEPA Agricultural staff identified an area in Clinton and Bond Counties in the Kaskaskia River basin and several upper Little Wabash River basin tributaries in Effingham and Cumberland Counties as candidate project areas.

  2. Estimated emissions of chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons based on an interspecies correlation method in the Pearl River Delta region, China.

    PubMed

    Wu, Jing; Fang, Xuekun; Martin, Jonathan W; Zhai, Zihan; Su, Shenshen; Hu, Xia; Han, Jiarui; Lu, Sihua; Wang, Chen; Zhang, Jianbo; Hu, Jianxin

    2014-02-01

    Although many studies have been conducted in recent years on the emissions of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs) at the large regional (such as East Asia) and national scales, relatively few studies have been conducted for cities or metropolitan areas. In this study, 192 air samples were collected in the Pearl River Delta (PRD) region of China in November 2010. The atmospheric mixing ratios of six halocarbons were analyzed, including trichlorofluoromethane (CFC-11, CCl3F), dichlorodifluoromethane (CFC-12, CCl2F2), monochlorodifluoromethane (HCFC-22, CHClF2), 1,1-dichloro-1-fluoroethane (HCFC-141b, CH3CCl2F), 1-dichloro-1,1-fluoroethane (HCFC-142b, CH3CClF2), and 1,1,1,2-tetrafluoroethane (HFC-134a, CH2FCF3), and their emissions were estimated based on an interspecies correlation method using HCFC-22 as the reference species. The results showed no significant change in the regional concentration and emission of CFC in the past 10years, suggesting that the continuous regional emission of CFC has had no significant effect on the CFC regional concentration in the PRD region. Concentrations and emissions of HCFCs and HFCs are significantly higher compared to previous research in the PRD region (P<0.05). The largest emission was for HCFC-22, most likely due to its substitution for CFC-12 in the industrial and commercial refrigeration subsector, and the rapid development of the room air-conditioner and extruded polystyrene subsectors. The PRD's ODP-weighted emissions of the target HCFCs provided 9% (7-12%) of the national emissions for the corresponding species. The PRD's GWP-weighted emissions of the target HCFCs and HFC-134a account for 10% (7-12%) and 8% (7-9%), respectively, of the national emissions for the corresponding species, and thus are important contributions to China's total emissions. PMID:24189105

  3. Investigation of polycyclic aromatic hydrocarbon level in blood and semen quality for residents in Pearl River Delta Region in China.

    PubMed

    Song, Xiao Fei; Chen, Zhi Yuan; Zang, Zhi Jun; Zhang, Ya Nan; Zeng, Feng; Peng, Yen Ping; Yang, Chen

    2013-10-01

    This study is the first one investigating the correlation between the concentration of polycyclic aromatic hydrocarbon (PAHs) in blood and semen qualities for residents in the Pearl River Delta (PRD) region in China. Blood samples from 53 infertile volunteers were studied for measures of semen quality and 16 PAHs. Information on the study subjects' living habits (such as smoking, drinking and preference of consumption for food) and general information (age, body-mass-index (BMI) and educational background) were also collected. Statistical results showed that age and BMI were significantly and negatively related to semen motilities. The total concentrations of PAHs (∑16 PAHs) in the blood were 12,010, 7493, 9105 and 8647ng/g for factory workers, office workers, technicians and salespersons, respectively. In addition, ∑16 PAHs in the blood of smokers, drinkers and heavy-taste food consumers were 11,950, 11,266 and 12,141ng/g, which were higher than those observed in nonsmokers (10,457ng/g), nondrinkers (10,920ng/g) and light-taste food consumers (9202ng/g), individually. Furthermore, the Pearson correlation analysis results showed significant positive correlations between BMI and ∑16 PAHs in the blood. Statistically significant correlations were observed between semen motilities and ∑16 PAHs in the blood as well. Logistic regression results showed that for each 1ng/g increase in ∑16 PAHs in blood samples, the log odds of experiencing a pregnancy decrease by 0.039 on average. However, more evidences are needed to clarify the impact of PAHs in the blood to male infertility. PMID:24021720

  4. Contribution of the aquitard to the regional groundwater hydrochemistry of the underlying confined aquifer in the Pearl River Delta, China.

    PubMed

    Wang, Ya; Jiao, Jiu Jimmy; Cherry, John A; Lee, Chun Ming

    2013-09-01

    Aquitards are capable of generating and preserving large amounts of chemicals. The release of the chemicals from the aquitards poses a potential contamination risk to groundwater that may be used as a drinking water source. This work aimed to identify the contribution of hydrogeochemical processes in the aquitards to groundwater hydrochemistry in the underlying confined basal aquifer by studying the coastal Quaternary aquifer-aquitard system of the Pearl River Delta, China. The system was submerged by paleo-seawater in the early Holocene and mainly receives infiltration of precipitation at present, as indicated by investigations on stable isotopes (δ(2)H, δ(18)O), water chemistry (SO4(2-) and Cl(-)) and salinity. Significant correlations between total dissolved solids in the basal aquifer and the thickness of the overlying aquitard further suggested the contribution of the aquitard to the groundwater hydrochemistry in the aquifer. Significant correlations between the chloride concentrations in aquitard porewater and that in groundwater in the aquifer, and between the thickness of the aquitard and the chloride concentrations in groundwater indicated the strong influence of the aquitard on the chloride in the aquifer. This is probably because the low-permeability aquitard is capable of preserving the paleo-seawater in the aquifer and releasing the salinity from the aquitard down to the aquifer via downward flow or diffusion. Isotopic and geochemical studies revealed that the aquitard is also responsible for generating and preserving large amounts of naturally occurring ammonium. Analysis between the concentrations of ammonium in groundwater in the basal aquifer and the total available ammonium in aquitard sediments suggested that the former is significantly controlled by the latter. PMID:23770547

  5. A study of control policy in the Pearl River Delta region by using the particulate matter source apportionment method

    NASA Astrophysics Data System (ADS)

    Wu, Dongwei; Fung, Jimmy Chi Hung; Yao, Teng; Lau, Alexis Kai Hon

    2013-09-01

    In recent years, Mainland China, and in particular the industrial hotbed of the Pearl River Delta (PRD) has experienced an increasingly serious problem of high concentrations of airborne particulate matter. Following the tightening-up of China's air quality policies in recent years, and with especially fine particles now added to a new air quality objective, the identification of major source regions and major types of pollutants has become crucial. In this study, the Comprehensive Air Quality Model (CAMx), together with the Particulate Source Apportionment Technology (PSAT) source apportionment method, has been applied to analyze how different emission activities influence PM concentration in the PRD region. By using this method, a detailed source region and emission category contribution matrix is derived for all regions within the Hong Kong/PRD region and source appointment results show that, on average, for different cities super-regional transport and mobile vehicles are the two major fine particle sources, contributing 62% (34.3 μg m-3) and 21% (12.2 μg m-3) of the total figure in December, and 42% (13.1 μg m-3) and 28% (9.7 μg m-3) in April. Meanwhile, over the same period in Hong Kong, in addition to these two factors, marine proved another very significant source of particle pollutant, amounting to 18% of the total figure (4.7 μg m-3). Another important cause of high PM levels has been the transport of fine particles between cities within the PRD region, with three different regions selected for detailed analysis. Results show that for the Hong Kong/PRD region local reduction of mobile sources and collaboration between different areas could have succeeded in alleviating the air pollution problem.

  6. The residual dynamic of polycyclic aromatic hydrocarbons and organochlorine pesticides in fishponds of the Pearl River delta, South China.

    PubMed

    Kong, K Y; Cheung, K C; Wong, C K C; Wong, M H

    2005-05-01

    Hong Kong and South China are the most developed regions within China. The industrialization in these areas has resulted in severe environmental problems. Sediment and biotic samples including tilapia (Oreochromis mossambicus), bighead carp (Aristichthys nobilis), grass carp (Ctenopharyngodon idellus), crucian carp (Carassius auratus) and mandarin fish/fresh water grouper (Siniperca chuatsi) were collected from different fishponds in the Pearl River Delta (Tanzhou, Sanjiao, Guangzhou, Shipai, Changan and Mai Po) for the analysis of polycyclic aromatic hydrocarbons (PAHs) and organochlorine (OC) pesticides. Mandarin fish, which belongs to the highest trophic level, accumulated the highest concentrations of PAHs and DDTs among all fish species. The levels of DDTs in fish samples ranged from 1.5 to 62ng g-1 (wet wt.), with more than 30% of the fish samples exceeding the limit of 14.4ng g-1 (wet wt.) for human consumption recommended by US EPA (2000). Levels of PAHs in fish samples ranged from 1.91 to 224.03ng g-1 (wet wt.), but the potency-weighted total concentrations of PAHs in all muscle tissues were below the guideline value of 0.67ng g-1 (wet wt.) for human consumption set by US EPA (2000). The guideline value calculated was based on a tissue consumption rate of 142.2g day-1 (4-5 meals per week), which is a more protective rate for populations with a high consumption of fish, like Chinese and Asians. The effect of lipid content in PAHs and DDTs accumulation in fish tissue was not significant in general. PMID:15899281

  7. Enrichment and mechanisms of heavy metal mobility in a coastal quaternary groundwater system of the Pearl River Delta, China.

    PubMed

    Wang, Ya; Jiao, Jiu Jimmy; Zhang, Ke; Zhou, Yongzhang

    2016-03-01

    The risks posed by heavy metal mobilization strongly depend on the pathways that the metals follow, with the sediment-water pathway representing a direct risk to groundwater contamination. Monitoring and sequential extraction experiments in the laboratory generally have limitations with respect to understanding the mechanisms of heavy metal mobilization in the field. The Quaternary coastal groundwater system of the Pearl River Delta, China was chosen as the study area to understand heavy metal enrichment and mobility. Heavy metals including V, Cr, Co, Ni, Cu, Zn, Ba, Pb, Mo, Cd, Sr, Ga, Ge, Rb, and Cs in both sediments and groundwater were analyzed. Geochemical parameters including Fe2O3, MnO, sedimentary organic matter, and carbonate content as well as hydrochemical parameters including K(+), Na(+), Ca(2+), Mg(2+), NH4(+), SO4(2-), Cl(-), HCO3(-), pH, TDS, and dissolved organic carbon were also measured. The enrichment of heavy metals in the solid sediment phase as well as the mobilization mechanisms of heavy metals in groundwater are discussed as informed by Pearson's correlation analysis. Hydrochemical analyses demonstrated that the mobility of V, Ba, Cr, Rb, and Cs is closely related to the decomposition of buried sedimentary organic matter; the mobility of Co, Ni, Cu, Zn, Pb, and Cd is closely linked with the reductive dissolution of Fe-Mn oxides; and the mobility of Co, Ni, Cu, Ba, Zn, Pb, Cd, Mn, Sr and Ga is probably controlled by ion exchange processes. This study demonstrates that heavy metal mobility in the field is not entirely consistent with the potential mobility as indicated by sediment analysis, due to the complicated hydrogeochemical conditions in the groundwater system, and suggests that comprehensive geochemical and hydrochemical studies are useful ways to understand the mobility mechanisms of heavy metals in the field. PMID:26760270

  8. Assessment of motor vehicle emission control policies using Model-3/CMAQ model for the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Che, Wenwei; Zheng, Junyu; Wang, Shuisheng; Zhong, Liuju; Lau, Alexis

    2011-03-01

    In recent decades, the Pearl River Delta (PRD) region located in south China has been experiencing severe air pollution, arising from the rapid increase in industry and motor vehicles. As a major contributing source to VOCs and NO x emissions, control of vehicular emissions plays a very important role in improving regional air quality. By taking 2015 as a target year, this paper assessed the impacts of five possible motor vehicle emission control measures and a combined policy scenario on ambient air quality in the PRD region, with the use of the Model-3/CMAQ (Community Multi-scale Air Quality) model. The results show: (1) an overall decreasing pattern in SO 2, NO 2 and PM 10 concentrations was found in central-south metropolitan areas of the PRD region for all measures, but increased O 3 concentrations may occur in these areas as well. The exception to this is that a slight decrease was observed for the cases of motorcycle restriction and introduction of HEV; (2) upgrading to National IV emission standards is the most effective individual measure and can reduce daily averaged NO 2 and PM 10 concentrations by 11.7 ppbV and 21.3 μg m -3, respectively; but involves an increase (at maximum) of 10.3ppbV in O 3 concentration. Evaluation of the combined scenario indicates that solely controlling motor vehicle emissions is not sufficient to improve PRD regional air quality significantly. O 3 and PM 10 concentrations under the same VOC/NO x reduction ratios exhibit differently at different locations, suggesting that integrated and location-specific pollution control strategies, considering co-control of multi-pollutants, are needed in this region in order to decrease primary and secondary pollutant concentrations simultaneously.

  9. Sources of C₂-C₄ alkenes, the most important ozone nonmethane hydrocarbon precursors in the Pearl River Delta region.

    PubMed

    Zhang, Yanli; Wang, Xinming; Zhang, Zhou; Lü, Sujun; Huang, Zhonghui; Li, Longfeng

    2015-01-01

    Surface ozone is becoming an increasing concern in China's megacities such as the urban centers located in the highly industrialized and densely populated Pearl River Delta (PRD) region, where previous studies suggested that ozone production is sensitive to VOC emissions with alkenes being important precursors. However, little was known about sources of alkenes. Here we present our monitoring of ambient volatile organic compounds at four representative urban, suburban and rural sites in the PRD region during November-December 2009, which experienced frequent ozone episodes. C2-C4 alkenes, whose total mixing ratios were 11-20% of non-methane hydrocarbons (NMHCs) quantified, accounted for 38-64% of ozone formation potentials (OFPs) and 30-50% of the total hydroxyl radical (OH) reactivity by NMHCs. Ethylene was the most abundant alkene, accounting for 8-15% in total mixing ratios of NMHCs and contributed 25-46% of OFPs. Correlations between C2-C4 alkenes and typical source tracers suggested that ethylene might be largely related to vehicle exhausts and industry activities, while propene and butenes were much more LPG-related. Positive Matrix Factorization (PMF) confirmed that vehicle exhaust and liquefied petroleum gas (LPG) were two major sources that altogether accounted for 52-62%, 58-77%, 73-83%, 68-79% and 73-84% for ethylene, propene, 1-butene, trans-2-butene and cis-2-butene, respectively. Vehicle exhausts alone contributed 32-49% ethylene and 35-41% propene. Industry activities contributed 13-23% ethylene and 7-20% propene. LPG instead contributed the most to butenes (38-65%) and substantially to propene (23-36%). Extensive tests confirmed high fractions of propene and butenes in LPG then used in Guangzhou and in LPG combustion plumes; therefore, limiting alkene contents in LPG would benefit regional ozone control. PMID:25260169

  10. Assessing ecosystem response to phosphorus and nitrogen limitation in the Pearl River plume using the Regional Ocean Modeling System (ROMS)

    NASA Astrophysics Data System (ADS)

    Gan, Jianping; Lu, Zhongming; Cheung, Anson; Dai, Minhan; Liang, Linlin; Harrison, Paul J.; Zhao, Xiaozheng

    2014-12-01

    The effect of phosphorus limitation on the Pearl River plume ecosystem, where large gradients in both nitrogen (N) and phosphorus (P) concentrations exist, is investigated in this process-oriented study by coupling the Regional Ocean Modeling System (ROMS) model with a new nitrogen, phosphorus, phytoplankton, zooplankton, and detritus (NPPZD) ecosystem model. The results of the N-based only model of Gan et al. (2010) were compared with those of the new NP-based model for the plume. The inclusion of P-limitation noticeably reduces the total phytoplankton production in the plume in the P-limited near and midfield regions of the plume. However, the nitrate in the plume extends farther downstream and forms a broad area of phytoplankton bloom in the N-limited far field. Moreover, it changes the photosynthetically active radiation and strengthens the subsurface chlorophyll maximum in the near and midfields, but weakens it in the far field. A high N:P ratio of ˜120 in the near field decreases quickly to a low N:P ratio of <13.3 in the far field due to a higher N:P consumption ratio and mixing with ambient waters with a lower N:P ratio. Mortality and coagulation acts as major sinks for phytoplankton production in the near and midfield during the developmental stage of the bloom, but grazing gradually becomes the most important sink for phytoplankton production in the entire plume during the mature stage. It was shown that the magnitudes of the difference between the NP-based and N-based cases decrease sequentially for nutrients, phytoplankton, and zooplankton.

  11. [Wastewater pollution characteristics from typical intensive pig farms in the Pearl River Delta and its ecological risk assessment].

    PubMed

    Li, Wen-Ying; Peng, Zhi-Ping; Yu, Jun-Hong; Huang, Ji-Chuan; Xu, Pei-Zhi; Yang, Shao-Hai

    2013-10-01

    Based on the wastewater quality investigation data from March 2009 to November 2011, wastewater qualities from typical intensive pig farms were assessed in the Pearl River Delta by single and comprehensive pollution index model. The results showed that key pollutants of piggery wastewater were fecal coliform (FC), total phosphorus (TP), chemical oxygen demand (COD) and biochemical oxygen demand (BOD), with their average mass concentrations of 1.98 x 10(9) CFU.L-1, 158.61 mg.L-1, 5 608.68 mg.L-1 and 1984.34 mg.L-1, respectively; key pollutants of biogas slurry were FC, TP, ammonia nitrogen (NH+4 -N) and suspended substance (SS), with their average mass concentrations of 8. 10 x 10(6) CFU.L-1, 81.76 mg.L-1, 476.24 mg.L-1 and 464.58 mg.L-1, respectively. Under the effect of wastewater pollutants, environment surrounding of typical intensive pig farms was seriously polluted, which decreased gradually from piggery wastewater to biogas slurry, and comprehensive pollution indices were 11.41, 6.91, 5.27, respectively. The risk analysis showed that the high-risk wastewater could never be discharged directly and irrigated crops. After the anaerobic treatment, FC, TP, NH+4 -N and SS were still strong factors with the potential ecological risk in the biogas slurry. In the long run, the ecological risk still exists for direct discharge or irrigation of them, and it is necessary to apply further treatment. PMID:24364317

  12. Estimation of health and economic costs of air pollution over the Pearl River Delta region in China.

    PubMed

    Lu, Xingcheng; Yao, Teng; Fung, Jimmy C H; Lin, Changqing

    2016-10-01

    The Pearl River Delta region (PRD) is the economic growth engine of China and also one of the most urbanized regions in the world. As a two-sided sword, rapid economic development causes air pollution and poses adverse health effects to the citizens in this area. This work estimated the negative health effects in the PRD caused by the four major ambient pollutants (SO2, NO2, O3 and PM10) from 2010 to 2013 by using a log linear exposure-response function and the WRF-CMAQ modeling system. Economic loss due to mortality and morbidity was evaluated by the value of statistical life (VSL) and cost of illness (COI) methods. The results show that the overall possible short-term all-cause mortality due to NO2, O3 and PM10 reached the highest in 2013 with the values being 13,217-22,800. The highest total economic loss, which ranged from 14,768 to 25,305million USD, occurred in 2013 and was equivalent to 1.4%-2.3% of the local gross domestic product. The monthly profile of cases of negative health effects varied by city and the types of ambient pollutants. The ratio of mortality attributed to air pollutants to total population was higher in urban areas than in rural areas. People living in the countryside should consider the possible adverse health effects of urban areas before they plan a move to the city. The results show that the health burden caused by the ambient pollutants over this region is serious and suggest that tighter control policies should be implemented in the future to reduce the level of air pollution. PMID:27220091

  13. Impacts of seasonal and regional variability in biogenic VOC emissions on surface ozone in the Pearl River Delta region, China

    SciTech Connect

    Situ, S.; Guenther, Alex B.; Wang, X. J.; Jiang, X.; Turnipseed, A.; Wu, Z.; Bai, J.; Wang, X.

    2013-12-05

    In this study, the BVOC emissions in November 2010 over the Pearl River Delta (PRD) region in southern China have been estimated by the latest version of a Biogenic Volatile Organic Compound (BVOC) emission model (MEGAN v2.1). The evaluation of MEGAN performance at a representative forest site within this region indicates MEGAN can estimate BVOC emissions reasonably well in this region except overestimating isoprene emission in autumn for reasons that are discussed in this manuscript. Along with the output from MEGAN, the Weather Research and Forecasting model with chemistry (WRF-Chem) is used to estimate the impacts of BVOC emissions on surface ozone in the PRD region. The results show BVOC emissions increase the daytime ozone peak by *3 ppb on average, and the max hourly impacts of BVOC emissions on the daytime ozone peak is 24.8 ppb. Surface ozone mixing ratios in the central area of Guangzhou- Foshan and the western Jiangmen are most sensitive to BVOC emissions BVOCs from outside and central PRD influence the central area of Guangzhou-Foshan and the western Jiangmen significantly while BVOCs from rural PRD mainly influence the western Jiangmen. The impacts of BVOC emissions on surface ozone differ in different PRD cities, and the impact varies in different seasons. Foshan and Jiangmen being most affected in autumn, result in 6.0 ppb and 5.5 ppb increases in surface ozone concentrations, while Guangzhou and Huizhou become more affected in summer. Three additional experiments concerning the sensitivity of surface ozone to MEGAN input variables show that surface ozone is more sensitive to landcover change, followed by emission factors and meteorology.

  14. Characterization of environmental Vibrio cholerae serogroups O1 and O139 in the Pearl River Estuary, China.

    PubMed

    Li, Xiujun; Wang, Duochun; Li, Baisheng; Zhou, Haijian; Liang, Song; Ke, Changwen; Deng, Xiaoling; Kan, Biao; Morris, J Glenn; Cao, Wuchun

    2016-02-01

    Toxigenic isolates of Vibrio cholerae serogroups O1 and O139 from aquatic reservoirs are a key source for recurrent epidemics of cholera in human populations. However, we do not have an optimal understanding of the microbiology of the strains within these reservoirs, particularly outside of the time periods when there are active cholera cases in the surrounding community. The main objective of the present study was to identify and characterize V. cholerae O1 and O139 in the Pearl River Estuary at a time when active disease was not being identified, despite prior occurrence of epidemic cholera in the region. Water samples were collected at 24 sites in the research area at monthly intervals between 2007 and 2010, and screened for the presence of V. cholerae O1 and O139. All isolates were screened for the presence of ctxAB, ompW, toxR, and tcpA genes. Multilocus variable number tandem repeat analysis (MLVA) was used to assess possible relationships among strains. The results show that Vibrio cholerae O1 or O139 was isolated, on average, from 6.7% of the sites screened at each time point. All V. cholerae O1 and O139 isolates were ctxAB negative, and 37% were positive for tcpA. Isolation was most common in the oldest, most urbanized district compared with other districts, and was associated with lower pH. Despite year-to-year variability in isolation rates, there was no evidence of seasonality. MLVA of 27 selected isolates showed evidence of high genetic diversity, with no evidence of clustering by year or geographic location. In this region where cholera has been epidemic in the past, there is evidence of environmental persistence of V. cholerae O1 and O139 strains. However, environmental strains were consistently nontoxigenic, with a high level of genetic diversity; their role as current or future agents of human disease remains uncertain. PMID:26674584

  15. Pore water nutrient characteristics and the fluxes across the sediment in the Pearl River estuary and adjacent waters, China

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Wang, Lu; Yin, Kedong; Lü, Ying; Zhang, Derong; Yang, Yongqiang; Huang, Xiaoping

    2013-11-01

    Spatio-temporal distribution of pore water nutrients and the fluxes at the sediment-water interface (SWI) were investigated to probe into the geochemical behavior of nutrients associated with early diagenesis of organic matter (OM), and to study the accumulation and transformation processes of nutrients at the SWI, as well as to discuss the impact of riverine inputs on nutrients in the Pearl River estuary (PRE) and adjacent offshore areas. Nutrient concentrations decreased from the upper to the lower reaches of the estuary, suggesting that there was a high input of anthropogenic nutrients and the estuary was acting as a nutrient sink. Dissolved inorganic nitrogen (DIN: the sum of NH4-N, NO3-N and NO2-N) concentrations in the water column and the pore water were higher in the estuary than at offshore areas due to the riverine discharge and the high accumulation rate in the estuary. NO3-N concentration was the highest of the three forms of DIN in the overlying water and showed a sharp decrease from the surficial sediment with increasing sediment depth, indicating that there was strong denitrification at the SWI. NH4-N, mainly deriving from the anaerobic degradation of OM, was the main form of DIN in the pore water and increased with depth. Negative NO3-N fluxes (into the sediment) and positive NH4-N fluxes (from the sediment) were commonly observed from incubation experiments, indicating the denitrification occurred at the SWI. DIN flux suggested that the sediment was a sink of DIN in spring, however, the sediment was the source of DIN in summer and winter. Nutrients dominantly diffused out of the sediment, suggesting that the sediment was the source of nutrients in spring at adjacent offshore areas. The fluxes directed that PO4-P mainly diffused into the sediment while SiO4-Si mainly diffused out of the sediment.

  16. Photochemical evolution of organic aerosols observed in urban plumes from Hong Kong and the Pearl River Delta of China

    NASA Astrophysics Data System (ADS)

    Zhou, Shengzhen; Wang, Tao; Wang, Zhe; Li, Weijun; Xu, Zheng; Wang, Xinfeng; Yuan, Chao; Poon, C. N.; Louie, Peter K. K.; Luk, Connie W. Y.; Wang, Wenxing

    2014-05-01

    Organic aerosols influence human health and global radiative forcing. However, their sources and evolution processes in the atmosphere are not completely understood. To study the aging and production of organic aerosols in a subtropical environment, we measured hourly resolved organic carbon (OC) and element carbon (EC) in PM2.5 at a receptor site (Tung Chung, TC) in Hong Kong from August 2011 to May 2012. The average OC concentrations exhibited the highest values in late autumn and were higher during the daytime than at night. The secondary organic carbon (SOC) concentrations, which were estimated using an EC-tracer method, comprised approximately half of the total OC on average. The SOC showed good correlation with odd oxygen (Ox = O3 + NO2) in the summer and autumn seasons, suggestive of contribution of photochemical activities to the formation of secondary organic aerosols (SOA). We calculated production rates of SOA using the photochemical age (defined as -Log10(NOx/NOy)) in urban plumes from the Pearl River Delta (PRD) region and Hong Kong during pollution episodes in summer and autumn. The CO-normalized SOC increased with the photochemical age, with production rates ranging from 1.31 to 1.82 μg m-3 ppmv-1 h-1 in autumn and with a larger rate in summer (3.86 μg m-3 ppmv-1 h-1). The rates are in the range of the rates observed in the outflow from Mexico City, the eastern U.S. and Los Angeles. Microscopic analyses of the individual aerosol particles revealed large contrasts of aerosol physico-chemical properties on clean and smoggy days, with thick organic coatings internally mixed with inorganic sulfate for all particle sizes in the aged plumes from the PRD region.

  17. 18 CFR 706.413 - Submission of statements by River Basin Commission Chairmen.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... statements by River Basin Commission Chairmen. 706.413 Section 706.413 Conservation of Power and Water... Financial Interests § 706.413 Submission of statements by River Basin Commission Chairmen. A statement of employment and financial interest is not required under this part from Chairmen of River Basin...

  18. 76 FR 13676 - Amended Columbia River Basin Fish and Wildlife Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ... POWER AND CONSERVATION PLANNING COUNCIL Amended Columbia River Basin Fish and Wildlife Program AGENCY... Council's Columbia River Basin Fish and Wildlife Program. SUMMARY: Pursuant to Section 4(h) of the Northwest Power Act, the Council has amended its Columbia River Basin Fish and Wildlife Program to add...

  19. 75 FR 64752 - Amended Columbia River Basin Fish and Wildlife Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... POWER AND CONSERVATION PLANNING COUNCIL Amended Columbia River Basin Fish and Wildlife Program AGENCY... Council's Columbia River Basin Fish and Wildlife Program. SUMMARY: Pursuant to Section 4(h) of the Northwest Power Act, the Council has amended its Columbia River Basin Fish and Wildlife Program to add...

  20. 18 CFR 701.209 - River basin commissions and field committees.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Box 908, Vancouver, Washington 98660; Upper Mississippi River Basin Commission, Federal Office... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false River basin commissions... RESOURCES COUNCIL COUNCIL ORGANIZATION Availability of Information § 701.209 River basin commissions...

  1. 18 CFR 701.209 - River basin commissions and field committees.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Box 908, Vancouver, Washington 98660; Upper Mississippi River Basin Commission, Federal Office... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true River basin commissions... RESOURCES COUNCIL COUNCIL ORGANIZATION Availability of Information § 701.209 River basin commissions...

  2. 18 CFR 701.209 - River basin commissions and field committees.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Box 908, Vancouver, Washington 98660; Upper Mississippi River Basin Commission, Federal Office... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false River basin commissions... RESOURCES COUNCIL COUNCIL ORGANIZATION Availability of Information § 701.209 River basin commissions...

  3. 18 CFR 701.209 - River basin commissions and field committees.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Box 908, Vancouver, Washington 98660; Upper Mississippi River Basin Commission, Federal Office... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false River basin commissions... RESOURCES COUNCIL COUNCIL ORGANIZATION Availability of Information § 701.209 River basin commissions...

  4. 18 CFR 701.209 - River basin commissions and field committees.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Box 908, Vancouver, Washington 98660; Upper Mississippi River Basin Commission, Federal Office... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false River basin commissions... RESOURCES COUNCIL COUNCIL ORGANIZATION Availability of Information § 701.209 River basin commissions...

  5. 77 FR 16558 - Yakima River Basin Conservation Advisory Group Charter Renewal

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-21

    ... Yakima River Basin Water Conservation Program. The basin conservation program is structured to provide... implementation of structural and nonstructural cost-effective water conservation measures in the Yakima River... Bureau of Reclamation Yakima River Basin Conservation Advisory Group Charter Renewal AGENCY: Bureau...

  6. 18 CFR 706.413 - Submission of statements by River Basin Commission Chairmen.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... statements by River Basin Commission Chairmen. 706.413 Section 706.413 Conservation of Power and Water... Financial Interests § 706.413 Submission of statements by River Basin Commission Chairmen. A statement of employment and financial interest is not required under this part from Chairmen of River Basin...

  7. Floods in the Skunk River basin, Iowa

    USGS Publications Warehouse

    Heinitz, Albert J.; Wiitala, Sulo Werner

    1978-01-01

    Evaluation of flood hazards, and the planning, design, and operation of various facilities on flood plains require information on floods. This report provides information on flood stages and discharges, flood magnitudes and frequency, and flood profiles for the Skunk River and some of its tributaries. It covers the Skunk -- South Skunk Rivers to Ames, and the lower reaches of tributaries as flows: Squaw Creek, 8.2 miles; Indian Creek, 11.6 miles; North Skunk River, 83.2 miles; Cedar Creek, 55.8 miles; and Big Creek, 21.7 miles.

  8. Change in community structure of planktonic Archaea from the lower Pearl River to the Northern South China Sea: Implications for archaeal ecological functions in different habitats

    NASA Astrophysics Data System (ADS)

    Xie, W.; Wang, P.; Zhou, X.; Guo, W.; Yang, S.; Zhang, C.

    2013-12-01

    Archaea are widespread and play an important role in the global carbon and nitrogen cycles. However, we still have limited knowledge about how the function of Archaea changes in varying habitats. The current paradigm is that change in community structure causes change in community function. Thus the goal of this study was to examine the change in community structure of planktonic Archaea from the Pearl River to the northern slope of the South China Sea in order to evaluate how archaeal ecological function changes along a salinity gradient. Pyrosequencing of the 16S rRNA gene of Archaea was performed on surface water samples that had salinity ranging from 0.0 in the river water to >3% toward the open ocean. The results showed that Methanomicrobiales and Miscellaneous Crenarchaeotal Group were abundant in the lower Pearl River, Nitrosopumilus-like species were abundant in estuary and shallow seawater (<50m), and Marine group II and III were abundant in the open ocean of deeper depth (50->4000m) of the North South China Sea. Methanomicrobiales are known methane-producing organisms and Nitrosopumilus is known to oxidize ammonia and fix CO2. Thus, the archaeal community appears to be able to perform methanogenesis in the freshwater and ammonia oxidation in the estuary and shallow sea with the major function being unknown toward the open ocean. The latter may be addressed by metagenomic studies that are currently underway.

  9. Spatial-temporal distribution and potential ecological risk assessment of nonylphenol and octylphenol in riverine outlets of Pearl River Delta, China.

    PubMed

    Chen, Ru; Yin, Pinghe; Zhao, Ling; Yu, Qiming; Hong, Aihua; Duan, Shunshan

    2014-11-01

    The aquatic environments of the Pearl River Delta in Southern China are subjected to contamination with various industrial chemicals from local industries. In this paper, the occurrence, seasonal variation and spatial distribution of alkylphenol octylphenol (OP) and nonylphenol (NP) in river surface water and sediments in the runoff outlets of the Pearl River Delta were investigated. NP and OP were detected in all water and sediment samples and their mean concentrations in surface water during the dry season ranged from 810 to 3366 ng/L and 85.5 to 581 ng/L, respectively, and those in sediments ranged from 14.2 to 95.2 ng/g dw and 0.4 to 3.0 ng/g dw, respectively. In surface water, much higher concentrations were detected in the dry season than those in the wet season. In sediments, the concentrations in the dry season were also mostly higher. High concentrations of NP and OP were found in Humen outlet, likely due to high levels of domestic and industrial wastewater discharges. An ecological risk assessment with the use of hazard quotient (HQ) was also carried out and the HQ values ranged from 3.6×10(-5) to 35 and 64% of samples gave a HQ>1, indicating that the current levels of NP and OP pose a significant risk to the relevant aquatic organisms in the region. PMID:25458690

  10. A Two-dimensional finite-element model study of backwater and flow distribution at the I-10 crossing of the Pearl River near Slidell, Louisiana

    USGS Publications Warehouse

    Lee, J.K.; Froelich, D.C.; Gilbert, J.J.; Wiche, G.J.

    1982-01-01

    A two-dimensional finite-element surface-water flow modeling system was used to study the effect of Interstate Highway 10 on water-surface elevations and flow distribution during the flood on the Pearl River on April 2, 1980, near Slidell, La. A finite-element network was designed to represent the topography and vegetative cover of the study reach. Hydrographic data collected for the 1980 flood were used to calibrate the flow model. The finite-element network was then modified to represent conditions prior to roadway construction, and the hydraulic impact of I-10 was determined by comparing ' before ' and ' after ' results. Upstream from the roadway, maximum backwater at the west edge of the flood plain (1.5 ft) is greater than maximum backwater at the east edge (1.1 ft). Backwater ranging from 0.6 to 0.2 ft. extends more than a mile downstream from the Pearl River bridge opening in I-10 at the east edge of the flood plain, and drawdown of 0.2 ft. or more occurs along approximately 2 miles of the west edge of the flood plain downstream from I-10. The capability of the modeling system to simulate the significant features of steady-state flow in a complicated multi-channel river-flood-plain system with variable topography and vegetative was successfully demonstrated in this study. (USGS)

  11. COMMENTS ON THE OHIO RIVER BASIN ENERGY STUDY

    EPA Science Inventory

    The Ohio River Basin Energy Study (ORBES) has been conducted by university researchers over a four-year period. During this time an Advisory Committee, which numbered up to 50 members, was active in critiquing and commenting on the research work. The committee included representa...

  12. COLUMBIA BASIN SALMON POPULATIONS AND RIVER ENVIRONMENT DATA

    EPA Science Inventory

    Data Access in Real Time (DART) provides an interactive data resource designed for research and management purposes relating to the Columbia Basin salmon populations and river environment. Currently, daily data plus historic information dating back to 1962 is accessible online. D...

  13. Nitrogen and Phosphorus Levels in the Yazoo River Basin, Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) and phosphorus (P) loadings to aquatic ecosystems are linked to environmental problems such as hypoxia. Presented is an assessment of accessible data on nutrient sources, sinks and inputs to streams within the Yazoo River Basin of northern Mississippi. Spatial trends were examined by p...

  14. BIG SIOUX RIVER DRAINAGE BASIN INFORMATION OUTREACH PROJECT

    EPA Science Inventory

    The main goal of the proposed project is to raise public awareness about the importance of protecting the Big Sioux River drainage basin. To accomplish this goal, the City and its partnering agencies are seeking to expand and improve public accessibility to a wide variety of r...

  15. BEAR RIVER BASIN, IDAHO - WATER QUALITY INVESTIGATION, 1974

    EPA Science Inventory

    The quality of the waters in the Bear River Basin, Idaho (160102) was surveyed from August 27 to August 29, 1974. The purposes of the survey were to determine point and non-point source loading, to determine whether water quality has improved since the adoption of the 1958 Enfor...

  16. Digital Atlas of the Upper Washita River Basin, Southwestern Oklahoma

    USGS Publications Warehouse

    Becker, Carol J.; Masoner, Jason R.; Scott, Jonathon C.

    2008-01-01

    Numerous types of environmental data have been collected in the upper Washita River basin in southwestern Oklahoma. However, to date these data have not been compiled into a format that can be comprehensively queried for the purpose of evaluating the effects of various conservation practices implemented to reduce agricultural runoff and erosion in parts of the upper Washita River basin. This U.S. Geological Survey publication, 'Digital atlas of the upper Washita River basin, southwestern Oklahoma' was created to assist with environmental analysis. This atlas contains 30 spatial data sets that can be used in environmental assessment and decision making for the upper Washita River basin. This digital atlas includes U.S. Geological Survey sampling sites and associated water-quality, biological, water-level, and streamflow data collected from 1903 to 2005. The data were retrieved from the U.S. Geological Survey National Water Information System database on September 29, 2005. Data sets are from the Geology, Geography, and Water disciplines of the U.S. Geological Survey and cover parts of Beckham, Caddo, Canadian, Comanche, Custer, Dewey, Grady, Kiowa, and Washita Counties in southwestern Oklahoma. A bibliography of past reports from the U.S. Geological Survey and other State and Federal agencies from 1949 to 2004 is included in the atlas. Additionally, reports by Becker (2001), Martin (2002), Fairchild and others (2004), and Miller and Stanley (2005) are provided in electronic format.

  17. WATERSHED NITROGEN AND PHOSPHOROUS BALANCE: THE UPPER POTOMAC RIVER BASIN

    EPA Science Inventory

    Nitrogen and phosphorus mass balances were estimated for the portion of the Potomac River basin watershed located above Washington, D.C. he total nitrogen (N) balance included seven input source terms, six sinks, and one "change-in-storage" term, but was simplified to five input ...

  18. Colorado River Basin Development Its Potential Impact on Tribal Life

    ERIC Educational Resources Information Center

    Hackenberg, Robert A.

    1976-01-01

    Since no mechanism presently exists for the effective distribution of tribal income to tribal members, the wealth created by development of natural resources on the American Indian reservations of the Colorado River Basin will not substantially alter the quality of Indian life. (JC)

  19. OHIO RIVER BASIN ENERGY STUDY: SOCIAL VALUES AND ENERGY POLICY

    EPA Science Inventory

    This report was prepared as part of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program supported by the Environmental Protection Agency. The objectives of the analysis are to identify American social values and to examine their relationship to ...

  20. Flood peaks and discharge summaries in the Delaware River basin

    USGS Publications Warehouse

    Vickers, A.A.; Farsett, Harry A.; Green, J. Wayne

    1981-01-01

    This report contains streamflow data from 299 continuous and partial-record gaging stations in the Delaware River basin. The location, drainage area, period of record, type of gage, and average flow (discharge) is given for each continuous station. Also included, are annual flood peak discharges and discharges above a selected base, annual and monthly mean discharges, and annual and monthly runoff. (USGS)

  1. Geothermal resources of the Southern Powder River Basin, Wyoming

    SciTech Connect

    Heasler, H.P.; Buelow, K.L.; Hinckley, B.S.

    1985-06-13

    This report describes the geothermal resources of the Southern Powder River Basin. The report contains a discussion of the hydrology as it relates to the movement of heated water, a description and interpretation of the thermal regime, and four maps: a generalized geological map, a structure contour map, a thermal gradient contour map, and a ground water temperature map. 10 figs. (ACR)

  2. The Delaware River Basin Landsat-Data Collection System Experiment

    NASA Technical Reports Server (NTRS)

    Paulson, R. W. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. This experiment successfully demonstrated that standard U.S. Geological Survey field instrumentation could be easily interfaced with the LANDSAT-DCS and the data made to flow smoothly to water resources management agencies. The experiment was conducted in the Delaware River basin. A truly operational system could not be deployed.

  3. FISH ASSEMBLAGE GROUPS IN THE UPPER TENNESSEE RIVER BASIN

    EPA Science Inventory

    A hierarchical clustering technique was used to classify sites in the upper Tennessee River basin based on relative abundance of fish species. Five site groups were identified. These groups differed mainly by the occurrence of minnow and darter species. Drainage area and ecore...

  4. AEROBIC DENITRIFICATION: IMPLICATIONS FOR THE MOM RIVER BASIN

    EPA Science Inventory

    Each year about 1.6 million metric tons of nitrogen, mostly from agriculture, is discharged from the lower Mississippi/Atchafalaya River Basin into the Gulf of Mexico, and each spring this excess nitrogen fuels the formation of a huge hypoxic zone in the Gulf. In the Mississippi...

  5. Water Temperature changes in the Mississippi River Basin

    EPA Science Inventory

    In this study, we demonstrate the transfer of a physically based semi-Lagrangian water temperature model (RBM) to EPA, its linkage with the Variable Infiltration Capacity (VIC) hydrology model, and its calibration to and demonstration for the Mississippi River Basin (MRB). The r...

  6. Salinity-dominated change in community structure and ecological function of Archaea from the lower Pearl River to coastal South China Sea.

    PubMed

    Xie, Wei; Zhang, Chuanlun; Zhou, Xuedan; Wang, Peng

    2014-09-01

    Archaea have multiple roles in global biogeochemical cycles. However, we still have limited knowledge about how environmental factors affect the diversity and function of different archaeal lineages. The goal of this study was to examine the change in the abundance and community structure of Archaea in the sediments collected from the lower Pearl River (mainly North River tributary), its estuary, and coastal South China Sea (SCS) in order to evaluate how archaeal ecological function might change along the salinity gradient. Pyrosequencing of the 16S rDNA gene of Archaea was performed on sediment samples from Feilaixia Dam on the North River tributary to Wanshan islands, which have a salinity range of 0.1 to 31.2‰. Consistent with the salt tolerance of cultivated representatives, methanogens in the genera Methanoregula, Methanosaeta, and Methanosarcina and Nitrososphaera within Thaumarchaeota of the ammonia-oxidizing Archaea (AOA) were abundant in freshwater sediments of the North River tributary, whereas the marine-associated genera Methanococcoides and Nitrosopumilus were the most abundant methanogens and AOA, respectively, in the estuary and coastal SCS. However, the percentages of total methanogens decreased and Thaumarchaeota increased with salinity, respectively. The phylum Crenarchaeota was largely represented by class-level lineages with no cultivated representatives, which collectively were more abundant in the estuary and coastal SCS in comparison to freshwater sites. This study indicates that salinity is the dominating factor affecting archaeal community structure and ecological function from the North River tributary of the Pearl River, its estuary, and coastal SCS, which is consistent with salinity control on microbial diversity in other regions of the world. PMID:24880629

  7. Impacts of urbanization on river system structure: a case study on Qinhuai River Basin, Yangtze River Delta.

    PubMed

    Ji, Xiaomin; Xu, Youpeng; Han, Longfei; Yang, Liu

    2014-01-01

    Stream structure is usually dominated by various human activities over a short term. An analysis of variation in stream structure from 1979 to 2009 in the Qinhuai River Basin, China, was performed based on remote sensing images and topographic maps by using ArcGIS. A series of river parameters derived from river geomorphology are listed to describe the status of river structure in the past and present. Results showed that urbanization caused a huge increase in the impervious area. The number of rivers in the study area has decreased and length of rivers has shortened. Over the 30 years, there was a 41.03% decrease in river length. Complexity and stability of streams have also changed and consequently the storage capacities of river channels in intensively urbanized areas are much lower than in moderately urbanized areas, indicating a greater risk of floods. Therefore, more attention should be paid to the urban disturbance to rivers. PMID:25116497

  8. Sharing water and benefits in transboundary river basins

    NASA Astrophysics Data System (ADS)

    Arjoon, Diane; Tilmant, Amaury; Herrmann, Markus

    2016-06-01

    The equitable sharing of benefits in transboundary river basins is necessary to solve disputes among riparian countries and to reach a consensus on basin-wide development and management activities. Benefit-sharing arrangements must be collaboratively developed to be perceived not only as efficient, but also as equitable in order to be considered acceptable to all riparian countries. The current literature mainly describes what is meant by the term benefit sharing in the context of transboundary river basins and discusses this from a conceptual point of view, but falls short of providing practical, institutional arrangements that ensure maximum economic welfare as well as collaboratively developed methods for encouraging the equitable sharing of benefits. In this study, we define an institutional arrangement that distributes welfare in a river basin by maximizing the economic benefits of water use and then sharing these benefits in an equitable manner using a method developed through stakeholder involvement. We describe a methodology in which (i) a hydrological model is used to allocate scarce water resources, in an economically efficient manner, to water users in a transboundary basin, (ii) water users are obliged to pay for water, and (iii) the total of these water charges is equitably redistributed as monetary compensation to users in an amount determined through the application of a sharing method developed by stakeholder input, thus based on a stakeholder vision of fairness, using an axiomatic approach. With the proposed benefit-sharing mechanism, the efficiency-equity trade-off still exists, but the extent of the imbalance is reduced because benefits are maximized and redistributed according to a key that has been collectively agreed upon by the participants. The whole system is overseen by a river basin authority. The methodology is applied to the Eastern Nile River basin as a case study. The described technique not only ensures economic efficiency, but may

  9. Analysis of thematic mapper simulator data acquired during winter season over Pearl River, Mississippi, test site

    NASA Technical Reports Server (NTRS)

    Anderson, J. E.; Kalcic, M. T. (Principal Investigator)

    1982-01-01

    Digital processed aircraft-acquired thematic mapping simulator (TMS) data collected during the winter season over a forested site in southern Mississippi are presented to investigate the utility of TMS data for use in forest inventories and monitoring. Analyses indicated that TMS data are capable of delineating the mixed forest land cover type to an accuracy of 92.5 % correct. The accuracies associated with river bottom forest and pine forest were 95.5 and 91.5 % correct. The accuracies associated with river bottom forest and pine forest were 95.5 and 91.5 % correct, respectively. The figures reflect the performance for products produced using the best subset of channels for each forest cover type. It was found that the choice of channels (subsets) has a significant effect on the accuracy of classification produced, and that the same channels are not the most desirable for all three forest types studied. Both supervised and unsupervised spectral signature development techniques are evaluated; the unsupervised methods proved unacceptable for the three forest types considered.

  10. Seasonal variation in sources and processing of particulate organic carbon in the Pearl River estuary, South China

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Ye, Feng; Xu, Shendong; Jia, Guodong

    2015-12-01

    Particulate organic carbon (POC) in the Pearl River estuary (PRE), South China, along a salinity gradient from freshwater to seawater in four months was studied in order to determine its temporal and spatial changes in source and processing. Analytical parameters included chlorophyll-a (Chl-a), POC, and carbon isotopic composition of POC and the dissolved inorganic carbon (DIC) (δ13CPOC, δ13CDIC). POC varied greatly from freshwater to seawater, exhibiting a significant power law distribution with a rapid decrease (from >2.5 mg l-1 to <0.9 mg l-1) in a narrow salinity range of 0-5 and then a slow decline to ˜0.4 mg l-1 along the large salinity gradient in the estuary. POC was sourced predominantly from in situ phytoplankton, and hence largely reflective of primary production, in February, August, and November as indicated by mostly lower POC/Chl-a values (<200), and significant correlation between POC and Chl-a, as well as between δ13CPOC and δ13CDIC. But in May, soil-derived OC was dominant in freshwater and low salinity estuarine water, as suggested by low POC% in total suspended substance, low Chl-a values and high POC/Chl-a ratios, and higher δ13CPOC values that was not in parallel with δ13CDIC excursion. The offset between δ13CPOC and phytoplankton δ13C (inferred from δ13CDIC) was trivial or positive in salinity <12, but then became negative downstream, which was likely suggestive of biogeochemical change from net respiration in the upper estuary to net production in the lower and outer estuary. Our results demonstrated that in situ phytoplankton was the dominant source to the estuarine POC pool during most seasons of a year, except in May in the first phase of wet season when rainfall and river flux increased abruptly causing intensive flushing effect. We further suggested that POC may be undergone intensive processing within the PRE, which is important for understanding organic carbon delivery in this vigorous land-ocean interface.

  11. Isotopic fingerprint of the middle Olt River basin, Romania.

    PubMed

    Popescu, Raluca; Costinel, Diana; Ionete, Roxana Elena; Axente, Damian

    2014-01-01

    One of the most important tributaries of the Danube River in Romania, the Olt River, was characterized in its middle catchment in terms of the isotopic composition using continuous flow-isotope ratio mass spectrometry (CF-IRMS). Throughout a period of 10 months, from November 2010 to August 2011, water samples from the Olt River and its more important tributaries were collected in order to investigate the seasonal and spatial isotope patterns of the basin waters. The results revealed a significant difference between the Olt River and its tributaries, by the fact that the Olt River waters show smaller seasonal variations in the stable isotopic composition and are more depleted in (18)O and (2)H. The waters present an overall enrichment in heavy isotopes during the warm seasons. PMID:25299076

  12. Contaminants in suspended sediment from the Fraser River basin

    SciTech Connect

    Sekela, M.; Baldazzi, C.; Moyle, G.; Brewer, R.

    1995-12-31

    The concentrations of trace organic contaminants were measured in suspended sediment samples collected upstream and downstream of six pulp mills located in the Fraser River basin. Sampling occurred at three hydrological periods; fall low flow, winter base flow (under ice) and spring freshet. Suspended sediments were analyzed for dioxins, furans, chlorinated phenolics and polycyclic aromatic hydrocarbons. Initial results indicate that (i) trace organic contaminants are detectable in suspended sediments collected over 265 river kilometers downstream of the nearest pulp mill; (ii) the 1992 to 1994 levels of 2,3,7,8-TCD-dioxin and 2,3,7,8-TCD-furan in Fraser river suspended sediments are lower than the levels measured in 1990; (iii) there is a measurable increase in trace organic contaminant levels in Fraser River suspended sediments associated with the initial rise in the Fraser River hydrograph at freshet.

  13. Feasible optimality of vegetation patterns in river basins

    NASA Astrophysics Data System (ADS)

    Caylor, Kelly K.; Scanlon, Todd M.; Rodriguez-Iturbe, Ignacio

    2004-07-01

    We examine mechanisms leading to organization of vegetation patterns within the channel network structure of a semi-arid New Mexico river basin under the controlling influence of water stress. We compare the actual pattern of water stress within the basin to patterns resulting from two algorithms of local stress optimization which proceed from an initial fully random vegetation distribution. Here we show that the distribution of vegetation and basin water stress derived from an algorithm that maintains local optimization within the network flow path exhibits considerably better agreement with the actual distribution than one that ignores the network structure of the basin. These results suggest the pattern of actual vegetation observed within the basin corresponds to a condition of feasible optimality in which organization is constrained by the stochastic nature of local interactions mediated by the network configuration. The principles of such organization have important consequences regarding the interaction between land cover change and hydrological dynamics in river basins, as well as the biogeographical evolution of landscapes.

  14. Quantifying the extent of river fragmentation by hydropower dams in the Sarapiquí River Basin, Costa Rica

    USGS Publications Warehouse

    Anderson, Elizabeth P.; Pringle, Catherine M.; Freeman, Mary C.

    2008-01-01

    Simple spatial analyses can be used as a predictive or planning tool for considering the effects of future dams in a basin-scale context. In the Sarapiquí River Basin, we recommend that future dam projects be constructed on already dammed rivers to minimize additional river fragmentation and to protect remaining riverine connectivity.

  15. 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.

  16. Hydrologic reconnaissance of the Noatak River basin, Alaska, 1978

    USGS Publications Warehouse

    Childers, Joseph M.; Kernodle, Donald R.

    1981-01-01

    Hydrologic data were collected in 1978 described water resources of the Noatak River basin, Alaska. Streamflow varies seasonally. No flow was observed from the upper part of the basin in late winter (April). In the lower part of the basin springs support perennial flow in the Kugururok River and downstream along the Noatak. The discharge of the Noatak was 150 cubic feet per second in April 1978. During the summer, rainstorms are common, and runoff produces high flow. During August 1978, flow was normal in the basin; unit runoff averaged about 1 cubic foot per second per square mile. The Noatak is a gravel-bed stream of moderate slope. It drops about 1,800 feet in elevation from a point near the head waters to the mouth, a distance of 400 miles. Streambed material in most places is gravel, cobbles, and boulders, maximum riffle depths and pool widths increase in a downstream direction. Stream velocity in August 1978 increased from about 1 foot per second in the upper basin to about 4 feet per second in the lower reaches. High-water marks of the maximum evident flood were found at elevations from bankfull to 5 feet above bankfull. Maximum evident flood unit runoff rates were estimated to be less than 50 cubic feet per second per square mile. Scars produced by ice jams were seldom seen above bankfull. Bank erosion appears to be most active in the lowlands. Water in the Noatak River basin is virtually unaffected by man 's activity. Water quality varies with location, weather, season, and source; the water is normally clear, cool, and hard. During late winter sea water intrudes into the Lower Noatak Canyon. Benthic invertebrate community composition and variability suggest the river 's undiminished natural quality. (USGS)

  17. On the coupled geomorphological and ecohydrological organization of river basins

    NASA Astrophysics Data System (ADS)

    Caylor, Kelly K.; Manfreda, Salvatore; Rodriguez-Iturbe, Ignacio

    2005-01-01

    This paper examines the linkage between the drainage network and the patterns of soil water balance components determined by the organization of vegetation, soils and climate in a semiarid river basin. Research during the last 10 years has conclusively shown an increasing degree of organization and unifying principles behind the structure of the drainage network and the three-dimensional geometry of river basins. This cohesion exists despite the infinite variety of shapes and forms one observes in natural watersheds. What has been relatively unexplored in a quantitative and general manner is the question of whether or not the interaction of vegetation, soils, and climate also display a similar set of unifying characteristics among the very different patterns they presents in river basins. A recently formulated framework for the water balance at the daily level links the observed patterns of basin organization to the soil moisture dynamics. Using available geospatial data, we assign soil, climate, and vegetation properties across the basin and analyze the probabilistic characteristics of steady-state soil moisture distribution. We investigate the presence of organization through the analysis of the spatial patterns of the steady-state soil moisture distribution, as well as in the distribution of observed vegetation patterns, simulated vegetation dynamic water stress and hydrological fluxes such as transpiration. Here we show that the drainage network acts as a template for the organization of both vegetation and hydrological patterns, which exhibit self-affine characteristics in their distribution across the river basin. Our analyses suggest the existence of a balance between the large-scale determinants of vegetation pattern reflecting optimality in the response to water stress and the random small-scale patterns that arise from local factors and ecological legacies such as those caused by dispersal, disturbance, and founder effects.

  18. Colorado River Basin Water Supply and Demand Study

    NASA Astrophysics Data System (ADS)

    Prairie, J. R.; Jerla, C.

    2012-12-01

    The Colorado River Basin Water Supply & Demand Study (Study), part of the Basin Study Program under the Department of the Interior's WaterSMART Program, is being conducted by the Bureau of Reclamation and agencies representing the seven Colorado River Basin States. The purpose of the Study is to assess future water supply and demand imbalances in the Colorado River Basin over the next 50 years and develop and evaluate options and strategies to resolve those imbalances. The Study is being conducted over the period from January 2010 to September 2012 and contains four major phases: Water Supply Assessment, Water Demand Assessment, System Reliability Analysis, and Development and Evaluation of Opportunities for balancing supply and demand. To address the considerable amount of uncertainty in projecting the future state of the Colorado River system, the Study has adopted a scenario planning approach that has resulted in four water supply scenarios and up to six water demand scenarios. The water supply scenarios consider hydrologic futures derived from the observed historical and paleo-reconstructed records as well as downscaled global climate model (GCM) projections. The water demand scenarios contain differing projections of parameters such as population growth, water use efficiency, irrigated acreage, and water use for energy that result in varying projections of future demand. Demand for outdoor municipal uses as well as agricultural uses were adjusted based on changing rates of evapotranspiration derived from downscaled GCM projections. Water supply and demand scenarios are combined through Reclamation's long-term planning model to project the effects of future supply and demand imbalances on Colorado River Basin resources. These projections lend to an assessment of the effectiveness of a broad range of options and strategies to address future imbalances.

  19. Balancing hydropower development in the Ohio River basin

    SciTech Connect

    Sale, M.J.; Railsback, S.F.; Chang, S.Y.; Coutant, C.C.; Spath, R.E.; Taylor, G.H.

    1989-01-01

    A large number of retrofit hydroelectric projects have been proposed at existing navigation dams in the Ohio River basin. These proposals involve potentially adverse environmental impacts, including reduced dissolved oxygen concentrations from decreased aeration at dams. The Federal Energy Regulatory Commission completed an environmental impact statement for 24 proposed projects at 19 dams on the Ohio, Monongahela, Allegheny, and Muskingum rivers, evaluating the cumulative impacts of hydropower development on more than 500 miles (800 km) of river. The use of models in this assessment proved extremely valuable for understanding the cumulative impacts of hydropower development on water quality in the basin and for balancing power and environmental quality considerations in the licensing process. 9 refs., 4 figs.

  20. Understanding Socio-Hydrology System in the Kissimmee River Basin

    NASA Astrophysics Data System (ADS)

    Chen, X.; Wang, D.; Tian, F.; Sivapalan, M.

    2014-12-01

    This study is to develop a conceptual socio-hydrology model for the Kissimmee River Basin. The Kissimmee River located in Florida was channelized in mid-20 century for flood protection. However, the environmental issues caused by channelization led Floridians to conduct a restoration project recently, focusing on wetland recovery. As a complex coupled human-water system, Kissimmee River Basin shows the typical socio-hydrology interactions. Hypothetically, the major reason to drive the system from channelization to restoration is that the community sensitivity towards the environment has changed from controlling to restoring. The model developed in this study includes 5 components: water balance, flood risk, wetland area, crop land area, and community sensitivity. Furthermore, urban population and rural population in the basin have different community sensitivities towards the hydrologic system. The urban population, who live further away from the river are more sensitive to wetland restoration; while the rural population, who live closer to the river are more sensitive to flood protection. The power dynamics between the two groups and its impact on management decision making is described in the model. The model is calibrated based on the observed watershed outflow, wetland area and crop land area. The results show that the overall focus of community sensitivity has changed from flood protection to wetland restoration in the past 60 years in Kissimmee River Basin, which confirms the study hypothesis. There are two main reasons for the community sensitivity change. Firstly, people's flood memory is fading because of the effective flood protection, while the continuously shrinking wetland and the decreasing bird and fish population draw more and more attention. Secondly, in the last 60 years, the urban population in Florida drastically increased compared with a much slower increase of rural population. As a result, the community sensitivity of urban population towards

  1. Aquatic risk assessment of priority and other river basin specific pesticides in surface waters of Mediterranean river basins.

    PubMed

    Silva, Emília; Daam, Michiel A; Cerejeira, Maria José

    2015-09-01

    To meet good chemical and ecological status, Member States are required to monitor priority substances and chemicals identified as substances of concern at European Union and local/river-basin/national level, respectively, in surface water bodies, and to report exceedances of the environmental quality standards (EQSs). Therefore, standards have to be set at national level for river basin specific pollutants. Pesticides used in dominant crops of several agricultural areas within the catchment of Mediterranean river basins ('Mondego', 'Sado' and 'Tejo', Portugal) were selected for monitoring, in addition to the pesticides included in priority lists defined in Europe. From the 29 pesticides and metabolites selected for the study, 20 were detected in surface waters of the river basins, seven of which were priority substances: alachlor, atrazine, chlorfenvinphos, chlorpyrifos, endosulfan, simazine and terbutryn, all of which exceeded their respective EQS values. QSs for other specific pollutants were calculated using different extrapolation techniques (i.e. deterministic or probabilistic) largely based on the method described in view of the Water Framework Directive. Non-acceptable aquatic risks were revealed for molinate, oxadiazon, pendimethalin, propanil, terbuthylazine, and the metabolite desethylatrazine. Implications of these findings for the classification of the ecological status of surface water bodies in Portugal and at the European level are discussed. PMID:26002046

  2. Chemical analyses of surface water in Illinois, 1975-77; Volume 2, Illinois River basin and Mississippi River tributaries north of Illinois River basin

    USGS Publications Warehouse

    Grason, David; Healy, R.W.

    1979-01-01

    Samples of surface water were collected and analyzed by the Illinois Environmental Protection Agency. The results from water years 1975 to 1977 are presented in three volumes. The history of sampling and analytical methods used during that period are summarized. Stream discharge data from records of the U.S. Geological Survey are included for all sites where samples were collected at gaging stations or near enough that reliable discharge estimates could be made. Volume II includes the Illinois River basin and Mississippi River tributaries north of Illinois River basin. (Woodard-USGS)

  3. Chemical analyses of surface water in Illinois, 1958-74; Volume II, Illinois River basin and Mississippi River tributaries north of Illinois River basin

    USGS Publications Warehouse

    Healy, R.W.; Toler, L.G.

    1978-01-01

    Samples of surface water were collected and analyzed by the Illinois Environmental Protection Agency and its predecessor, the Stream Pollution Control Bureau of the Illinois Department of Public Health. The results for the period 1958 to 1974 are presented in tabular form and the history of sampling and analytical methods are included for all sites where samples were collected at gaging stations or near enough that reliable discharge estimates could be made. The report is contained in three volumes. This volume (Volume II) includes Illinois River basin and Mississippi River tributaries north of Illinois River basin. (See also W78-10034 and W78-10036) (Woodard-USGS)

  4. Transport of diazinon in the San Joaquin River basin, California

    USGS Publications Warehouse

    Kratzer, Charles R.

    1997-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water to water fleas in February 1993. Previous studies focussed mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River, the Merced, Tuolumne, and Stanislaus Rivers, and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated traveltimes, ephemeral west-side creeks were probably the main diazinon source early in the storms, while the Tuolumne and Merced Rivers and east-side drainage directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 199193 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceeding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 micrograms per liter, a concentration shown to be acutely toxic to water fleas. Diazinon concentrations were highly variable during the storms and frequent sampling was required to adequately describe the concentration curves and to estimate loads.

  5. Carbon-Water-Energy Relations for Selected River Basins

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.

    1998-01-01

    A biophysical process-based model was run using satellite, assimilated and ancillary data for four years (1987-1990) to calculate components of total evaporation (transpiration, interception, soil and snow evaporation), net radiation, absorbed photosynthetically active radiation and net primary productivity over the global land surface. Satellite observations provided fractional vegetation cover, solar and photosynthetically active radiation incident of the surface, surface albedo, fractional cloud cover, air temperature and vapor pressure. The friction velocity and surface air pressure are obtained from a four dimensional data assimilation results, while precipitation is either only surface observations or a blended product of surface and satellite observations. All surface and satellite data are monthly mean values; precipitation has been disaggregated into daily values. All biophysical parameters of the model are prescribed according to published records. From these global land surface calculations results for river basins are derived using digital templates of basin boundaries. Comparisons with field observations (micrometeorologic, catchment water balance, biomass production) and atmospheric water budget analysis for monthly evaporation from six river basins have been done to assess errors in the calculations. Comparisons are also made with previous estimates of zonal variations of evaporation and net primary productivity. Efficiencies of transpiration, total evaporation and radiation use, and evaporative fraction for selected river basins will be presented.

  6. Geothermal resources of the Wind River Basin, Wyoming

    SciTech Connect

    Hinckley, B.S.; Heasler, H.P.

    1985-01-01

    The geothermal resources of the Wind River Basin were investigated. Oil-well bottom-hole temperatures, thermal logs of wells, and heat flow data have been interpreted within a framework of geologic and hydrologic constraints. Basic thermal data, which includes the background thermal gradient and the highest recorded temperature and corresponding depth for each basin, is tabulated. Background heat flow in the Wind River Basin is generally insufficient to produce high conductive gradients. Only where hydrologic systems re-distribute heat through mass movement of water will high temperatures occur at shallow depths. Aquifers which may have the confinement and structural characteristics necessary to create such geothermal systems are the Lance/Fort Union, Mesa Verde, Frontier, Muddy, Cloverly, Sundance, Nugget, Park City, Tensleep, Amsden, Madison, Bighorn, and Flathead Formations. Of these the Tensleep Sandstone and Madison Limestone are the most attractive in terms of both productivity and water quality. Most of the identified geothermal anomalies in the Wind River Basin occur along complex structures in the southwest and south. The most attractive geothermal prospects identified are anomalous Areas 2 and 3 north of Lander, Sweetwater Station Springs west of Jeffrey City, and the thermal springs southwest of Dubois. Even in these areas, it is unlikely temperatures in excess of 130 to 150/sup 0/F can be developed. 16 refs., 7 figs., 7 tabs. (ACR)

  7. Environmental Setting of the Lower Merced River Basin, California

    USGS Publications Warehouse

    Gronberg, Jo Ann M.; Kratzer, Charles R.

    2006-01-01

    In 1991, the U.S. Geological Survey began to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology as part of the National Water-Quality Assessment (NAWQA) Program. As part of this program, the San Joaquin-Tulare Basins study unit is assessing parts of the lower Merced River Basin, California. This report provides descriptions of natural and anthropogenic features of this basin as background information to assess the influence of these and other factors on water quality. The lower Merced River Basin, which encompasses the Mustang Creek Subbasin, gently slopes from the northeast to the southwest toward the San Joaquin River. The arid to semiarid climate is characterized by hot summers (highs of mid 90 degrees Fahrenheit) and mild winters (lows of mid 30 degrees Fahrenheit). Annual precipitation is highly variable, with long periods of drought and above normal precipitation. Population is estimated at about 39,230 for 2000. The watershed is predominately agricultural on the valley floor. Approximately 2.2 million pounds active ingredient of pesticides and an estimated 17.6 million pounds active ingredient of nitrogen and phosphorus fertilizer is applied annually to the agricultural land.

  8. Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) in Forest Soils from Urban to Rural Areas in the Pearl River Delta of Southern China

    PubMed Central

    Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

    2014-01-01

    The upper layer of forest soils (0–20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban–suburban–rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area. PMID:24599040

  9. Temporal trends of nonylphenol and bisphenol A contamination in the Pearl River Estuary and the adjacent South China Sea recorded by dated sedimentary cores.

    PubMed

    Peng, Xianzhi; Wang, Zhendi; Mai, Bixian; Chen, Fanrong; Chen, Shejun; Tan, Jianhua; Yu, Yiyi; Tang, Caiming; Li, Kechang; Zhang, Gan; Yang, Chun

    2007-10-01

    Three dated sedimentary cores were collected for the investigation of temporal trends and the environmental loadings of nonylphenol (NP) and bisphenol A (BPA) in recent decades in the Pearl River Estuary (PRE), South China and the adjacent South China Sea (SCS). The peak fluxes of NP and BPA occurred in the mid-1980s in the PRE, coincident with the rapid economic growth in China. The decline of NP and BPA fluxes is attributable to the implementation of sewage treatment in the late 1980s in the Pearl River Delta (PRD). Multi-model distributions were observed for the fluxes of NP and BPA in the SCS with the peak fluxes occurring in the late 1950s and the mid-1970s respectively. The fluxes of NP and BPA have increased since the 1990s due to the lack of adequate wastewater treatment facilities and the constant economic growth. Nonylphenol was quantifiably detected in sediments predating its widespread application (1940s), suggesting the downward penetration of NP in the sediment columns. The characterization results revealed that NP and BPA were preserved well and the isomer-selective degradation of NP did not occur significantly in the sediment cores. The environmental loadings of NP and BPA in the PRE sediments were roughly estimated to be 124 t and 1.7 t respectively over the past 30 years. PMID:17618676

  10. An eight year (2005-2013) temporal trend of halogenated organic pollutants in fish 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

    2015-04-15

    Dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), 2,3,5,6-tetrabromo-p-xylene (pTBX) and pentabromotoluene (PBT) were measured in baby croaker (Collichthys lucidus) and mullet (Osteomugil ophuyseni) collected in 2005 and 2013 from the Pearl River Estuary. DDTs, HCHs, PCBs, and PBDEs were detected in two fish species at concentrations of 150-8100, 1.4-120, 22-560, 2.2-280 ng/g lipid wt., respectively. The levels of these chemicals were significantly lower in 2013 than in 2005. The compositions for DDTs, HCHs, and PBDEs in 2013 differed from those in 2005, indicating source changes between the two sampling periods. DP, pTBX and PBT were detected at concentrations of ND-130 ng/g lipid wt. No clear temporal trends were found for these contaminants. Overall, these results indicated the effectiveness of regulations and source controls in substantively reducing inputs of these contaminants to the Pearl River Estuary. PMID:25769908

  11. Information technology and decision support tools for stakeholder-driven river basin salinity management

    SciTech Connect

    Quinn, N.W.T; Cozad, D.B.; Lee, G.

    2010-01-01

    Innovative strategies for effective basin-scale salinity management have been developed in the Hunter River Basin of Australia and more recently in the San Joaquin River Basin of California. In both instances web-based stakeholder information dissemination has been a key to achieving a high level of stakeholder involvement and the formulation of effective decision support salinity management tools. A common element to implementation of salinity management strategies in both river basins has been the concept of river assimilative capacity for controlling export salt loading and the potential for trading of the right to discharge salt load to the river - the Hunter River in Australia and the San Joaquin River in California. Both rivers provide basin drainage and the means of exporting salt to the ocean. The paper compares and contrasts the use of monitoring, modeling and information dissemination in the two basins to achieve environmental compliance and sustain irrigated agriculture in an equitable and socially and politically acceptable manner.

  12. [Effect of hydrochemistry characteristics under impact of human activity: a case study in the upper reaches of the Xijiang River basin].

    PubMed

    Yu, Shil; Sun, Ping-an; Du, Wen-yue; He, Shi-yi; Li, Rui

    2015-01-01

    In this paper, observation and sampling were taken three times a month in a hydrological year for three typical sections of the middle and upper reaches of the Xijiang River basin, based on the data of hydrochemistry and flow, the article mainly discusses the evolution process of hydrochemistry in river under natural process and impact of human activity. Hydrochemical characteristics of 116. samples were analyzed in the study area. The hydrochemistry type in the middle and upper reaches of the Xijiang River basin belonged to HCO3- -Ca2+ type, and the chemical weathering type mainly came from carbonate rock weathering. Ca2+ and HCO3- were the main cations and anions, which reflected that hydrochemical characteristics of river in karst area mainly affected by the dissolution of carbonate rock. Na, Mg2, Ca2+ and Cl- mainly affected by natural conditions, the impact of human activity was little. K+, NO3-, SO4(2-) and HCO3- were affected by human activity in different degrees, and it showed different influence ways. This study had an important significance for the change of river hydrochemistry, water quality characteristics, and the effect on substance transported fluxes in the downstream of Pearl River and water quality protection in South China Monsoon Area. PMID:25898649

  13. Integrated Watershed Assessment: The Northern River Basins Study

    NASA Astrophysics Data System (ADS)

    Wrona, F. J.; Gummer, W. D.

    2001-05-01

    Begun in 1991 and completed in 1996, the Northern River Basins Study (NRBS) was a \\$12 M initiative established by the governments of Canada, Alberta, and the Northwest Territories to assess the cumulative impacts of development, particularly pulp mill related effluent discharges, on the health of the Peace, Athabasca and Slave river basins. The NRBS was launched in response to concerns expressed by northern residents following the 1991 approval of the Alberta Pacific Pulp Mill in Athabasca. Although initiated by governments, the NRBS was set-up to be `arms-length' and was managed by a 25 member Study Board that represented the many interests in the basins, including industry, environmental groups, aboriginal peoples, health, agriculture, education, municipalities, and the federal, territorial and provincial governments. Overseen by an independent Science Advisory Committee, an integrated research program was designed covering eight scientific components: fate and distribution of contaminants, food chain impacts, nutrients, hydrology/hydraulics and sediment transport, uses of the water resources, drinking water quality, traditional knowledge, and synthesis/modeling. Using a 'weight of evidence' approach with a range of ecological and sociological indicators, cumulative impacts from pulp and paper-related discharges and other point and non-point sources of pollution were determined in relation to the health and contaminant levels of aquatic biota, nutrient and dissolved oxygen-related stress, hydrology and climate related changes, and human health and use of the river basins. Based on this assessment and Study Board deliberations, site-specific and basin-wide scientific and management-related recommendations were made to Ministers regarding regulatory and policy changes, basin management and monitoring options, and future research. The Study reinforces the importance of conducting ecosystem-based , interdisciplinary science and the need for public involvement in

  14. Development of river flood model in lower reach of urbanized river basin

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kouhei; Tajima, Yoshimitsu; Sanuki, Hiroshi; Shibuo, Yoshihiro; Sato, Shinji; Lee, SungAe; Furumai, Hiroaki; Koike, Toshio

    2014-05-01

    Japan, with its natural mountainous landscape, has demographic feature that population is concentrated in lower reach of elevation close to the coast, and therefore flood damage with large socio-economic value tends to occur in low-lying region. Modeling of river flood in such low-lying urbanized river basin is complex due to the following reasons. In upstream it has been experienced urbanization, which changed land covers from natural forest or agricultural fields to residential or industrial area. Hence rate of infiltration and runoff are quite different from natural hydrological settings. In downstream, paved covers and construct of sewerage system in urbanized areas affect direct discharges and it enhances higher and faster flood peak arrival. Also tidal effect from river mouth strongly affects water levels in rivers, which must be taken into account. We develop an integrated river flood model in lower reach of urbanized areas to be able to address above described complex feature, by integrating model components: LSM coupled distributed hydrological model that models anthropogenic influence on river discharges to downstream; urban hydrological model that simulates run off response in urbanized areas; Saint Venant's equation approximated river model that integrates upstream and urban hydrological models with considering tidal effect from downstream. These features are integrated in a common modeling framework so that model interaction can be directly performed. The model is applied to the Tsurumi river basin, urbanized low-lying river basin in Yokohama and model results show that it can simulate water levels in rivers with acceptable model errors. Furthermore the model is able to install miscellaneous water planning constructs, such as runoff reduction pond in urbanized area, flood control field along the river channel, levee, etc. This can be a useful tool to investigate cost performance of hypothetical water management plan against impact of climate change in

  15. Water resources planning for a river basin with recurrent wildfires.

    PubMed

    Santos, R M B; Sanches Fernandes, L F; Pereira, M G; Cortes, R M V; Pacheco, F A L

    2015-09-01

    Situated in the north of Portugal, the Beça River basin is subject to recurrent wildfires, which produce serious consequences on soil erosion and nutrient exports, namely by deteriorating the water quality in the basin. In the present study, the ECO Lab tool embedded in the Mike Hydro Basin software was used for the evaluation of river water quality, in particular the dissolved concentration of phosphorus in the period 1990-2013. The phosphorus concentrations are influenced by the burned area and the river flow discharge, but the hydrologic conditions prevail: in a wet year (2000, 16.3 km(2) of burned area) with an average flow of 16.4 m(3)·s(-1) the maximum phosphorus concentration was as low as 0.02 mg·L(-1), while in a dry year (2005, 24.4 km(2) of burned area) with an average flow of 2 m(3)·s(-1) the maximum concentration was as high as 0.57 mg·L(-1). Phosphorus concentrations in the water bodies exceeded the bounds of good ecological status in 2005 and between 2009 and 2012, water for human consumption in 2009 and water for multiple uses in 2010. The River Covas, a right margin tributary of Beça River, is the most appropriate stream as regards the use of water for human consumption, because it presents the biggest water potential with the best water quality. Since wildfires in the basin result essentially from natural causes and climate change forecasts indicate an increase in their frequency and intensity in the near future, forestry measures are proposed to include as a priority the conversion of stands of maritime pine in mixed stands of conifer and hardwood species. PMID:25918888

  16. Role of river bank erosion in sediment budgets of catchments within the Loire river basin (France)

    NASA Astrophysics Data System (ADS)

    Gay, Aurore; Cerdan, Olivier; Poisvert, Cecile; Landemaine, Valentin

    2014-05-01

    Quantifying volumes of sediments produced on hillslopes or in channels and transported or stored within river systems is necessary to establish sediment budgets. If research efforts on hillslope erosion processes have led to a relatively good understanding and quantification of local sources, in-channel processes remain poorly understood and quasi inexistent in global budgets. However, profound landuse changes and agricultural practices have altered river functioning, caused river bank instability and stream incision. During the past decades in France, river channelization has been perfomed extensively to allow for new agricultural practices to take place. Starting from a recent study on the quantification of sediment fluxes for catchments within the Loire river basin (Gay et al. 2013), our aim is to complete sediment budgets by taking into account various sources and sinks both on hillslope and within channel. The emphasis of this study is on river bank erosion and how bank erosion contributes to global budgets. A model of bank retreat is developed for the entire Loire river basin. In general, our results show that bank retreat is on average quite low with approximately 1 cm.yr-1. However, a strong variability exists within the study area with channels displaying values of bank retreat up to ~10 cm.yr-1. Our results corroborate those found by Landemaine et al. in 2013 on a small agricultural catchment. From this first step, quantification of volumes of sediment eroded from banks and available for transport should be calculated and integrated in sediment budgets to allow for a better understanding of basin functioning. Gay A., Cerdan O., Delmas M., Desmet M., Variability of sediment yields in the Loire river basin (France): the role of small scale catchments (under review). Landemaine V., Gay A., Cerdan O., Salvador-Blanes S., Rodriguez S. Recent morphological evolution of a headwater stream in agricultural context after channelization in the Ligoire river (France

  17. Groundwater quality in the Mohawk River Basin, New York, 2011

    USGS Publications Warehouse

    Nystrom, Elizabeth A.; Scott, Tia-Marie

    2013-01-01

    Water samples were collected from 21 production and domestic wells in the Mohawk River Basin in New York in July 2011 to characterize groundwater quality in the basin. The samples were collected and processed using standard U.S. Geological Survey procedures and were analyzed for 148 physiochemical properties and constituents, including dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds (VOCs), radionuclides, and indicator bacteria. The Mohawk River Basin covers 3,500 square miles in New York and is underlain by shale, sandstone, carbonate, and crystalline bedrock. The bedrock is overlain by till in much of the basin, but surficial deposits of saturated sand and gravel are present in some areas. Nine of the wells sampled in the Mohawk River Basin are completed in sand and gravel deposits, and 12 are completed in bedrock. Groundwater in the Mohawk River Basin was typically neutral or slightly basic; the water typically was very hard. Bicarbonate, chloride, calcium, and sodium were the major ions with the greatest median concentrations; the dominant nutrient was nitrate. Methane was detected in 15 samples. Strontium, iron, barium, boron, and manganese were the trace elements with the highest median concentrations. Four pesticides, all herbicides or their degradates, were detected in four samples at trace levels; three VOCs, including chloroform and two solvents, were detected in four samples. The greatest radon-222 activity, 2,300 picocuries per liter, was measured in a sample from a bedrock well, but the median radon activity was higher in samples from sand and gravel wells than in samples from bedrock wells. Coliform bacteria were detected in five samples with a maximum of 92 colony-forming units per 100 milliliters. Water quality in the Mohawk River Basin is generally good, but concentrations of some constituents equaled or exceeded current or proposed Federal or New York State drinking-water standards. The standards

  18. Coho Salmon Master Plan, Clearwater River Basin.

    SciTech Connect

    Nez Perce Tribe; FishPro

    2004-10-01

    The Nez Perce Tribe has a desire and a goal to reintroduce and restore coho salmon to the Clearwater River Subbasin at levels of abundance and productivity sufficient to support sustainable runs and annual harvest. Consistent with the Clearwater Subbasin Plan (EcoVista 2003), the Nez Perce Tribe envisions developing an annual escapement of 14,000 coho salmon to the Clearwater River Subbasin. In 1994, the Nez Perce Tribe began coho reintroduction by securing eggs through U.S. v. Oregon; by 1998 this agreement provided an annual transfer of 550,000 coho salmon smolts from lower Columbia River hatchery facilities for release in the Clearwater River Subbasin. In 1998, the Northwest Power and Conservation Council authorized the Bonneville Power Administration to fund the development of a Master Plan to guide this reintroduction effort. This Master Plan describes the results of experimental releases of coho salmon in the Clearwater River Subbasin, which have been ongoing since 1995. These data are combined with results of recent coho reintroduction efforts by the Yakama Nation, general coho life history information, and historical information regarding the distribution and life history of Snake River coho salmon. This information is used to assess a number of alternative strategies aimed at restoring coho salmon to historical habitats in the Clearwater River subbasin. These data suggest that there is a high probability that coho salmon can be restored to the Clearwater River subbasin. In addition, the data also suggest that the re-establishment of coho salmon could be substantially aided by: (1) the construction of low-tech acclimation facilities; (2) the establishment of a 'localized' stock of coho salmon; and (3) the construction of hatchery facilities to provide a source of juvenile coho salmon for future supplementation activities. The Nez Perce Tribe recognizes that there are factors which may limit the success of coho reintroduction. As a result of these

  19. Distribution and speciation of metals (Cu, Zn, Cd, and Pb) in agricultural and non-agricultural soils near a stream upriver from the Pearl River, China.

    PubMed

    Yang, Silin; Zhou, Dequn; Yu, Huayong; Wei, Rong; Pan, Bo

    2013-06-01

    The distribution and chemical speciation of typical metals (Cu, Zn, Cd and Pb) in agricultural and non-agricultural soils were investigated in the area of Nanpan River, upstream of the Pearl River. The investigated four metals showed higher concentrations in agricultural soils than in non-agricultural soils, and the site located in factory district contained metals much higher than the other sampling sites. These observations suggested that human activities, such as water irrigation, fertilizer and pesticide applications might have a major impact on the distribution of metals. Metal speciation analysis presented that Cu, Zn and Cd were dominated by the residual fraction, while Pb was dominated by the reducible fraction. Because of the low mobility of the metals in the investigated area, no remarkable difference could be observed between upstream and downstream separated by the factory site. PMID:23466733

  20. Estimates of anthropogenic halocarbon emissions based on its measured ratios relative to CO in the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Shao, M.; Huang, D. K.; Gu, D. S.; Lu, S. H.; Chang, C. C.; Wang, J.-L.

    2011-01-01

    Using a GC/FID/MS system, we analyzed the mixing ratio levels of 16 halocarbon species in more than 100 air samples collected in 2004 from the Pearl River Delta (PRD) region of southern China. The results revealed elevated regional mixing ratios for most halocarbons, especially for HClC = CCl2 (trichloroethylene, TCE), CH2Cl2 (dichloromethane, DCM), CH3Br (bromomethane), HCFC-22, CHCl3 (trichloromethane), CCl4 (tetrachloromethane), Cl2C = CCl2 (perchloroethylene, PCE), CH3CCl3 (methyl chloroform, MCF), and CFC-12. Comparisons were done with the data from TRACE-P and ALE/GAGE/AGAGE experiments, we found that the large variability in concentrations (relative standard deviation ranged from 9.31% to 96.55%) of the halocarbons suggested substantial local emissions from the PRD region in 2004. Correlations between the mixing ratio of each species and carbon monoxide (CO) were examined, and then each emission of halocarbon was quantified based on scaling the optimized CO emission inventory with the slope of the regression line fitted to each species relative to CO. The calculated results revealed that mass of CH2Cl2 (7.0 Gg), CH3CCl3 (6.7 Gg), and Cl2C = CCl2 (2.3 Gg) accounted for about 62.9% of total emissions, suggesting a significant contribution to halocarbon emissions from solvent use in the PRD region. Emissions of HCFC-22 (3.5 Gg), an alternative refrigerant to chlorofluorocarbons (CFCs), were about 2.3 times greater than those of CFC-12 (1.6 Gg). CFC-12 and HCFC-22 accounted for 21.5% of total emissions of halocarbons, so that the refrigerant would be the second largest source of halocarbons. However, the ratio approach found only minor emissions of other CFCs, such as CFC-11, and levels of CFC-114 and CFC-113 were close to zero. Emissions of other anthropogenic halocarbons, such as CCl4, CHCl3, CH3Br, and CH3Cl, were also estimated. Where possible, the emissions estimated from the measured ratios were compared with results from source inventory techniques, we

  1. Change of air quality and its impact on atmospheric visibility in central-western Pearl River Delta.

    PubMed

    Wan, Jun-Ming; Lin, Mang; Chan, Chuen-Yu; Zhang, Zhi-Sheng; Engling, Guenter; Wang, Xue-Mei; Chan, Iat-Neng; Li, Shi-Yu

    2011-01-01

    Ambient air quality data, including atmospheric visibility, of Foshan city, a highly polluted city in the Pearl River Delta (PRD), and data obtained by the On-line Air Pollutant Exhaust Monitoring Network (OAPEMN), recently established by the National Emission Monitoring and Control Network for major industrial enterprises, were analyzed and are reported here for the first time, revealing the change in air pollution patterns and its impact on visibility degradation in the last decade. Reduced visibility of less than 8 km (after elimination of rainy and foggy periods) was found 22% of the time from 1998 to 2008, accompanied by elevated levels of pollutants, especially SO₂ and PM₁₀, in comparison with that of other developed cities. However, PM₁₀ showed a steady decreasing trend (0.004 mg m⁻³) year⁻¹) during 2001-2008, in contrast to the noticeable increase in ambient NO₂ concentrations from ~0.020 mg m⁻³ before 2005 to above 0.050 mg m⁻³ afterward. Multiple regression analysis revealed that the percentage of reduced visibility strongly correlated with PM₁₀ concentration, suggesting that visibility degradation was directly proportional to the loading of particles. Moreover, the fairly significant correlation between reduced visibility and NO₂ concentration also implied that the impact of primary emissions of NO₂ and enhanced secondary pollutants, formed via photochemical processes in the atmosphere, could not be ignored. The decreased PM₁₀levels were obviously the predominant factor for the improvement in visibility (5.0% per 0.01 mg m⁻³) and were likely due to the implementation of stricter air pollution control measures for industrial exhaust, which also resulted in reduced SO₂ pollution levels in the recent 2 years. In particular, the OAPEMN records showed an overall enhanced SO₂ removal by 64% in major industrial sectors. The continuous increase in road traffic and lack of efficient NO(x) control strategies in the PRD

  2. Temporal trends and spatial variations of ozone-depleting substances (ODS) in the Pearl River Delta (PRD) region, southern China

    NASA Astrophysics Data System (ADS)

    Zhang, Yanli; Wang, Xinming; Blake, Donald; Simpson, Isobel

    2014-05-01

    Long-term observation of mixing ratios of ozone-depleting substances (ODS) in ambient air can help to assess the implementation of the Montreal Protocol and Its Amendments in regional and national scales. Here we present our measurement of ODS such as CFCs, HCFCs, halons and other halocarbons in ambient air since 2000 in the Pearl River Delta (PRD) region, one of the most densely populated and highly industrialized regions that was supposed to be a hotspot for ODS emission in China. These halocarbons in the PRD region were found to have 5-348% enhancements when compared to their global background levels. CFC-12 and CFC-11 in the region, for example, were 37-56% and 12-43%, respectively, above their global background levels. CFC replacement compounds showed even larger enhancements. In average mixing ratios of HCFC-22, HCFC-141b, and HCFC-142b were 89%, 87%, and 86% above their background levels of 148 ppt, 12.1 ppt, and 12.1 ppt in the year of 2000, respectively; and 72%, 125%, and 52% over their background levels of 205 ppt, 20.2 ppt, and 20.0 ppt in the year of 2009, respectively. During 2000-2009, CFCs in the PRD region showed decline trends with the decreasing rates of -3.0, -5.9, and -9.4 ppt/yr for CFC-12, CFC-11, and CFC-113, respectively; these rates were faster than that at the global background sites, which were -0.91, -2.12, and -0.69 ppt/yr, respectively. The CFCs substitutes HCFC-22, HCFC-141b, and HCFC-142b, however, showed increasing trends with the increasing rates of 8.0, 2.6, and 0.9 ppt/yr, respectively. HFC-134a, a refrigerant used for mobile air conditioning, showed rapid increase with a rate of 15 ppt/yr from 2000 to 2009 in the region. As for other halocarbons, methyl chloroform and carbon tetrachloride decreased with rates of 21 and 1 ppt/yr during the period. The mixing ratios of methyl chloride in the region showed unusual rapid increase at a rate of 64 ppt/yr when compared to its increasing rate of 1.3 ppt/yr at the global background

  3. Annual dynamics of impervious surface in the Pearl River Delta, China, from 1988 to 2013, using time series Landsat imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Weng, Qihao

    2016-03-01

    Information on impervious surface distribution and dynamics is useful for understanding urbanization and its impacts on hydrological cycle, water management, surface energy balances, urban heat island, and biodiversity. Numerous methods have been developed and successfully applied to estimate impervious surfaces. Previous methods of impervious surface estimation mainly focused on the spectral differences between impervious surfaces and other land covers. Moreover, the accuracy of estimation from single or multi-temporal images was often limited by the mixed pixel problem in coarse- or medium-resolution imagery or by the intra-class spectral variability problem in high resolution imagery. Time series satellite imagery provides potential to resolve the above problems as well as the spectral confusion with similar surface characteristics due to phenological change, inter-annual climatic variability, and long-term changes of vegetation. Since Landsat time series has a long record with an effective spatial resolution, this study aimed at estimating and mapping impervious surfaces by analyzing temporal spectral differences between impervious and pervious surfaces that were extracted from dense time series Landsat imagery. Specifically, this study developed an efficient method to extract annual impervious surfaces from time series Landsat data and applied it to the Pearl River Delta, southern China, from 1988 to 2013. The annual classification accuracy yielded from 71% to 91% for all classes, while the mapping accuracy of impervious surfaces ranged from 80.5% to 94.5%. Furthermore, it is found that the use of more than 50% of Scan Line Corrector (SLC)-off images after 2003 did not substantially reduced annual classification accuracy, which ranged from 78% to 91%. It is also worthy to note that more than 80% of classification accuracies were achieved in both 2002 and 2010 despite of more than 40% of cloud cover detected in these two years. These results suggested that the

  4. Estimate of anthropogenic halocarbon emission based on measured ratio relative to CO in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Shao, M.; Huang, D.; Gu, D.; Lu, S.; Chang, C.; Wang, J.

    2011-05-01

    Using a GC/FID/MS system, we analyzed the mixing ratio of 16 halocarbon species in more than 100 air samples collected in 2004 from the Pearl River Delta (PRD) region of southern China. The results revealed that there are elevated mixing ratios for most of halocarbons, especially for HClC = CCl2 (trichloroethylene, TCE), CH2Cl2 (dichloromethane, DCM), CH3 Br (bromomethane), HCFC-22, CHCl3 (trichloromethane), CCl4 (tetrachloromethane), Cl2C = CCl2 (perchloroethylene, PCE), CH3CCl3 (methyl chloroform, MCF), and CFC-12. Comparisons were done with the data from TRACE-P and ALE/GAGE/AGAGE experiments, we found that the large variability in mixing ratios (relative standard deviation ranged from 9.31 % to 96.55 %) of the halocarbons suggested substantial local emissions from the PRD region in 2004. Correlations between the mixing ratio of each species and carbon monoxide (CO) was examined, and then the emission of each halocarbon was quantified based on scaling the optimized CO emission inventory with the slope of the regression line fitted to each species relative to CO. The calculated results revealed that mass of CH2Cl2 (7.0 Gg), CH3CCl3 (6.7 Gg), and Cl2C = CCl2 (2.3 Gg) accounted for about 62.9 % of total halocarbon emissions, it suggested a significant contribution from solvent use in the PRD region. Emissions of HCFC-22 (3.5 Gg), an alternative refrigerant to chlorofluorocarbons (CFCs), were about 2.3 times greater than those of CFC-12 (1.6 Gg). CFC-12 and HCFC-22 accounted for 21.5 % of total emissions of halocarbons, so that the refrigerant would be the second largest source of halocarbons. However, the ratio approach found only minor emissions of CFCs, such as CFC-11, and the emission of CFC-114 and CFC-113 were close to zero. Emissions of other anthropogenic halocarbons, such as CCl4, CHCl3, CH3Br, and CH3Cl, were also estimated. Where possible, the emissions estimated from the measured ratios were compared with results from source inventory techniques, we

  5. [Impacts of landscape patterns on heavy metal contamination of agricultural top soils in the Pearl River Delta, South China].

    PubMed

    Li, Cheng; Li, Fang-bai; Wu, Zhi-feng; Cheng, Jiong

    2015-04-01

    Landscape patterns are known to influence many ecological processes, but the relationship between landscape patterns and soil pollution processes is not well understood. Based on 300 top soil samples, land use and cover map for the Pearl River Delta (PRD) of 2005, this study explored the characteristics and spatial pattern of heavy metal contamination of agricultural top soils and examined the impacts of landscape patterns on the heavy metal contamination in the buffers of soil samples. Research methods included geostatistical analysis, landscape pattern analysis, single-factor pollution indices, and Pearson correlation analysis. We found that: 1) out of the 235 agricultural soil samples, 3.8%, 0.4%, 17.0% and 9.4% samples exceeded the Grade II national standard for As, Pb, Cd and Ni concentrations respectively. High pollution levels were found in three cities, Guangzhou, Foshan and Zhongshan; 2) soils in the farmland were more polluted than those in the forest and orchard land, and there were no differences among different agricultural land use types in contamination level of each heavy metal (except Cd); and 3) the proportion, mean patch area as well as the degree of landscape fragmentation, landscape-level structural complexity and aggregation/connectivity of water at the buffer zone were significantly positively correlated with the contamination level of each of the four heavy metals in agricultural top soils. Part of the landscape pattern of urban land in the buffer zone also positively correlated with Pb and Cd levels (P < 0.05). On the contrary, the proportion, mean patch area and aggregation degree of forest land negatively correlated with soil Pb and Ni levels (P < 0.05); and 4) the closer to the industry land were the soil samples, the more polluted the soils were for Pb, Cd and Ni. Only landscape diversity was found to be positively correlated with soil Cd contamination. The study results provide new information and scientific basis for heavy metal

  6. Source origins, modeled profiles, and apportionments of halogenated hydrocarbons in the greater Pearl River Delta region, southern China

    NASA Astrophysics Data System (ADS)

    Guo, H.; Ding, A. J.; Wang, T.; Simpson, I. J.; Blake, D. R.; Barletta, B.; Meinardi, S.; Rowland, F. S.; Saunders, S. M.; Fu, T. M.; Hung, W. T.; Li, Y. S.

    2009-06-01

    We analyze 16-month data of 13 major halocarbons measured at a southern China coastal site in the greater Pearl River Delta (PRD). A total of 188 canister air samples were collected from August 2001 to December 2002. Overall inspection indicated that CH2Cl2, C2Cl4, and C2HCl3 had similar temporal variations while CFC-11, CFC-12, and CFC-113 showed the same emission patterns during the sampling period. Diurnal variations of halocarbons presented different patterns during ozone episode days, mainly related to emission strength, atmospheric dispersion, and photochemical lifetimes. For further statistics and source appointment, Lagrangian backward particle release simulations were conducted to help understand the potential source regions of all samples and classify them into different categories, including local Hong Kong, inner PRD, continental China, and marine air masses. With the exception of HCFC-142b, the mixing ratios of all halocarbons in marine air were significantly lower than those in urban and regional air (p < 0.01), whereas no significant difference was found between urban Hong Kong and inner PRD regional air, reflecting the dominant impact of the greater PRD regional air on the halocarbon levels. The halocarbon levels in this region were significantly influenced by anthropogenic sources, causing the halocarbon mixing ratios in South China Sea air to be higher than the corresponding background levels, as measured by global surface networks and by airborne missions such as Transport and Chemical Evolution Over the Pacific. Interspecies correlation analysis suggests that CHCl3 is mainly used as a solvent in Hong Kong but mostly as a feedstock for HCFC-22 in the inner PRD. Furthermore, CH3Cl is often used as a refrigerant and emitted from biomass/biofuel burning in the inner PRD. A positive matrix factorization receptor model was applied to the classified halocarbon samples in the greater PRD for source profiles and apportionments. Seven major sources were

  7. Occurrence, phase distribution, and mass loadings of benzothiazoles in riverine runoff of the Pearl River Delta, China.

    PubMed

    Ni, Hong-Gang; Lu, Feng-Hui; Luo, Xian-lin; Tian, Hui-Yu; Zeng, Eddy Y

    2008-03-15

    A set of six benzothiazoles was determined in riverine runoff samples of the Pearl River Delta (PRD) collected monthly from March 2005 to February 2006. The concentrations of total benzothiazoles ranged from 220 to 611 ng/L, with benzothiazole (BT) being the most prominent (82%), followed by 2-methylthiobenzothiazole (MBT),thianaphthene (TN), and triphenylene (TP). The annual fluxes ofTN, BT, MBT, dibenzothiophene (DBT), 2-(4-morpholinyl)benzothiazole (24MoBT), and TP from the PRD to the coastal ocean were 1.94, 65.1, 10.1,0.63, 0.18, and 0.89 tons/yr, summing to yield an annual flux of 79 tons/yr for total benzothiazoles. In the PRD, approximately 1.1 x 10(5) tons of rubber are estimated to be released into the environment each year. This corresponds to the annual fluxes of 13 tons/yr for BT and 0.4 tons/yr for 24MoBT from tire particles. The annual fluxes of BT from scrap tires from Japan, Korea, Brazil, the European Union, the United States, and China were 99, 21, 36, 270, 328, and 120 tons/yr, respectively. The fluxes of 24MoBT from the same countries were 3.0, 0.5, 1.1, 8.4, 10.3, and 3.8 tons/ yr, respectively. These results indicated that tire-wear particles and scrap tires are the dominant sources of benzothiazoles in the environment. By comparison, Asia may be the major contributor to the global input of benzothiazoles from auto tires in the coming years. Overall, the six benzothiazoles under investigation appeared to be suitable tracers of pollutant inputs to surface runoff within the PRD aquatic system. In addition, 24MoBT seemed more appropriate than BT to trace tire rubber residues and therefore can be a good indicator of economic development and urbanization in a specific region. PMID:18409609

  8. The Effects of Socioeconomic and Environmental Factors on the Incidence of Dengue Fever in the Pearl River Delta, China, 2013

    PubMed Central

    Li, Yue; Meng, Yujie; Chen, Qianqian; Ma, Jiaqi; Gao, George F.

    2015-01-01

    Background An outbreak of dengue fever (DF) occurred in Guangdong Province, China in 2013 with the highest number of cases observed within the preceding ten years. DF cases were clustered in the Pearl River Delta economic zone (PRD) in Guangdong Province, which accounted for 99.6% of all cases in Guangdong province in 2013. The main vector in PRD was Aedes albopictus. We investigated the socioeconomic and environmental factors at the township level and explored how the independent variables jointly affect the DF epidemic in the PRD. Methodology/Principal Findings Six factors associated with the incidence of DF were identified in this project, representing the urbanization, poverty, accessibility and vegetation, and were considered to be core contributors to the occurrence of DF from the perspective of the social economy and the environment. Analyses were performed with Generalized Additive Models (GAM) to fit parametric and non-parametric functions to the relationships between the response and predictors. We used a spline-smooth technique and plotted the predicted against the observed co-variable value. The distribution of DF cases was over-dispersed and fit the negative binomial function better. The effects of all six socioeconomic and environmental variables were found to be significant at the 0.001 level and the model explained 45.1% of the deviance by DF incidence. There was a higher risk of DF infection among people living at the prefectural boundary or in the urban areas than among those living in other areas in the PRD. The relative risk of living at the prefectural boundary was higher than that of living in the urban areas. The associations between the DF cases and population density, GDP per capita, road density, and NDVI were nonlinear. In general, higher “road density” or lower “GDP per capita” were considered to be consistent risk factors. Moreover, higher or lower values of “population density” and “NDVI” could result in an increase in

  9. Comparison of aerosol hygroscopicity and mixing state between winter and summer seasons in Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Jiang, Rongxin; Tan, Haobo; Tang, Lili; Cai, Mingfu; Yin, Yan; Li, Fei; Liu, Li; Xu, Hanbing; Chan, P. W.; Deng, Xuejiao; Wu, Dui

    2016-03-01

    environment. Hence, only assuming a constant mixing state of soot particles, such as pure external or internal for the regional climate model and air quality model is still not realistic and may lead to uncertainties for the Pearl River Delta (PRD) region which is one of the three major economic regions in China. Comparing the diurnal variation of NFNH in both seasons, it seems that such a diurnal cycle was mainly related to the differences in evolution of mixing layer between two seasons. Such quantitative hygroscopic properties of sub-micro particles are essential in assessing their impact on weather-climate effect and atmospheric visibility.

  10. Analysis of alternative modifications for reducing backwater at the Interstate Highway 10 crossing of the Pearl River near Slidell, Louisiana

    USGS Publications Warehouse

    Wiche, Gregg J.; Gilbert, J.J.; Froehlich, David C.; Lee, Jonathan K.

    1988-01-01

    In April 1979 and April 1980, major flooding along the lower Pearl River caused extensive damage to homes located on the flood plain in the Slidell, Louisiana, area. In response to questions about causes of these floods and means of mitigating future floods, the U.S. Geological Survey, in cooperation with the Louisiana Department of Transportation and Development, Office of Highways, and the U.S. Department of Transportation, Federal Highway Administration, used a two-dimensional finite-element surface-water flow-modeling system to study the effect of four alternative modifications for improving the hydraulic characteristics of the Interstate Highway 10 crossing of the flood plain near Slidell. The analysis used the model's capability to simulate changes in flood-plain topography, flood-plain vegetative cover, and highway-embankment geometry. Compared with the existing highway crossing, the four alternative modifications reduce backwater and average velocities through bridge openings for a flood of the magnitude of the 1980 flood. The four alternatives also eliminate roadway overtopping during such a flood. For the four modifications, maximum backwater on the west side of the flood plain ranges from 0.3 to 1.1 feet and on the east side from 0.3 to 0.7 foot. Results of the alternative-model simulations show that backwater is greater on the west side of the flood plain than on the east side, but upstream from Interstate Highway 10 backwater decreases more rapidly in the upstream direction on the west side of the flood plain than on the east side. Downstream from Interstate Highway 10, modeling of the four alternatives indicates that backwater and drawdown still occur on the east and west sides of the flood plain, respectively, but are less than the values computed for the April 1980 flood with Interstate Highway 10 in place. In addition to other highway-crossing modifications, alternatives 2 and 3 include simulation of a new 2,000-foot bridge opening, and

  11. Water Quality of the upper Litani River Basin, Lebanon

    NASA Astrophysics Data System (ADS)

    Haydar, Chaden Moussa; Nehme, Nada; Awad, Sadek; Koubaissy, Bachar; Fakih, Mohamad; Yaacoub, Ali; Toufaily, Joumana; Villeras, Frederic; Hamieh, Tayssir

    Water pollution is a major problem in Lebanon, which is has been exacerbated lately. However, surface water sources are most exploited, and more certainly the water from rivers. The Litani River has been lately subjected to several aspects of deterioration in its quality. This includes the major physiochemical characteristics. The aims of this study are to assess the seasonal variations in water quality in the Upper Litani River Basin, including the Qaraaoun Lake. The collected samples were from representative sites along the river, and this was carried out at several dates during 2010 and 2011. The carried analysis implies the physical (pH, T°, TDS, EC), chemicals (Na+, Ca2+, Mg2+, Cl-, SO2-4, NH3+, NO-3, PO2-4, K+, Heavy metals. This resulted numeric data are being compared with WHO guidelines. In addition, PCA was applied to evaluate the data accuracy. It can be conclude that the measured variables used are creditable for the assessment.

  12. Channeling in Paleocene coals, northern Powder River basin, Montana

    SciTech Connect

    Hansen, W.B.

    1983-08-01

    Interpretation of 1,200 geophysical logs in the northern Powder River basin, Montana, reveals the paleodrainages influencing coal deposition during the deposition of the Tongue River member (Paleocene, Fort Union Formation). Four channels with associated crevasse splay deposits are recognized: (1) an east-west rosebud drainage near Colstrip, (2) a north-south wall channel near Birney, (3) a north-south Dietz drainage near Tongue River Reservoir, and (4) a north-south Anderson channel in the vicinity of Moorhead. These channels support the concept of a major northeast-flowing drainage system during deposition of the Tongue River Member. Identification of these channels serves as a guide to future coal exploration.

  13. People and water in the Assabet River basin, eastern Massachusetts

    USGS Publications Warehouse

    DeSimone, Leslie A.

    2005-01-01

    An accounting of the inflows, outflows, and uses of water in the rapidly developing Assabet River Basin, along Interstate 495 in eastern Massachusetts, was done to quantify how people's activities alter the hydrologic system. The study identified subbasins and seasons in which outflows resulting from people's activities were relatively large percentages of total flows, and quantified the fraction of streamflow in the Assabet River that is treated wastewater. Computer models of ground-water flow were also used to test how the components of the hydrologic system, particularly streamflow, would change with future development and increased water use. Computer simulations showed that, when water use was increased to currently permitted levels, streamflows in tributaries would decrease, particularly during the low-flow period. In the Assabet River, increased wastewater discharges resulted in a slight increase in total streamflow and an increase in the fraction of streamflow in the river that is wastewater, relative to existing conditions.

  14. River Sinuosity Classification - Case study in the Pannonian Basin

    NASA Astrophysics Data System (ADS)

    Petrovszki, J.; Székely, B.; Timár, G.

    2012-04-01

    A new evaluation method is proposed to classify the multiple window-size based sinuosity spectrum, in order to minimize the possible human interpretation error. If the river is long enough for the analysis, the classification could be similarly useful as the sinuosity spectrum is, but sometimes it is more straightforward. Furthermore, for the classification, we did not need the main parameters of the river, e.g. the bankfull discharge. The river sinuosity values were studied in the Pannonian Basin in order to reveal neotectonic influence on their abrupt changes. The map sheets of the Second Military Survey of the Habsburg Empire were used to digitize the natural, pre-regulation meandering river thalwegs. 28 rivers were studied, and the connection between the known fault lines and the river sinuosity changes was detected in 36 points, along 26 structural lines. An unsupervised ISOCLASS classification was carried out on these data, and the sinuosity values were divided into 5 classes. Because of the sinuosity calculation method, 25 kilometer-long river sections are missing at the two endpoints of the channel. So sometimes the displayed section of the river does not cross to the faults represented on the neotectonic map. In the other cases, where the faults are crossing the rivers, the results are corresponding with the results of the sinuosity spectrum: the river-points on the two sides of the faults belong to different classes. The connection between these fault lines and the change of river sinuosity classes was detected in 23 points, along 16 structural lines The research is made in the frame of project OTKA-NK83400 (SourceSink Hungary). The European Union and the European Social Fund also have provided financial support to the project under the grant agreement no. TÁMOP 4.2.1./B-09/1/KMR-2010-0003.

  15. River enhancement in the Upper Mississippi River basin: Approaches based on river uses, alterations, and management agencies

    USGS Publications Warehouse

    O'Donnell, T. K.; Galat, D.L.

    2007-01-01

    The Upper Mississippi River is characterized by a series of locks and dams, shallow impoundments, and thousands of river channelization structures that facilitate commercial navigation between Minneapolis, Minnesota, and Cairo, Illinois. Agriculture and urban development over the past 200 years have degraded water quality and increased the rate of sediment and nutrient delivery to surface waters. River enhancement has become an important management tool employed to address causes and effects of surface water degradation and river modification in the Upper Mississippi River Basin. We report information on individual river enhancement projects and contrast project densities, goals, activities, monitoring, and cost between commercially non-navigated and navigated rivers (Non-navigated and Navigated Rivers, respectively). The total number of river enhancement projects collected during this effort was 62,108. Cost of all projects reporting spending between 1972 and 2006 was about US$1.6 billion. Water quality management was the most cited project goal within the basin. Other important goals in Navigated Rivers included in-stream habitat improvement and flow modification. Most projects collected for Non-navigated Rivers and their watersheds originated from the U.S. Department of Agriculture (USDA). The U.S. Army Corps of Engineers and the USDA were important sources for projects in Navigated Rivers. Collaborative efforts between agencies that implement projects in Non-navigated and Navigated Rivers may be needed to more effectively address river impairment. However, the current state of data sources tracking river enhancement projects deters efficient and broad-scale integration. ?? Journal compilation ?? 2007 Society for Ecological Restoration International.

  16. Occurrence and sources of perfluoroalkyl acids in Italian river basins.

    PubMed

    Valsecchi, Sara; Rusconi, Marianna; Mazzoni, Michela; Viviano, Gaetano; Pagnotta, Romano; Zaghi, Carlo; Serrini, Giuliana; Polesello, Stefano

    2015-06-01

    This paper presents a survey on the occurrence and sources of 11 perfluoroalkyl acids (PFAA) in the main river basins in Italy, covering about 40% of the Italian surface area and 45% of the Italian population. Total concentrations of PFAA ranged fromrivers impacted by industrial discharges. Among the rivers directly flowing into the sea, Brenta, Po and Arno present significant concentrations, while concentrations in Tevere and Adige, which are not impacted by relevant industrial activities, are almost all below the detection limits. The total estimated PFAA load of the five rivers was 7.5ty(-1) with the following percentage distribution: 39% PFBS, 32% PFOA, 22% short chain perfluorocarboxylic acids (PFCA), 6% PFOS and 1% long chain PFCA. PFOA and PFOS loads, evaluated in the present work, represent 10% and 2% of the estimated European loads, respectively. In Italy the most important sources of PFAA are two chemical plants which produce fluorinated polymers and intermediates, sited in the basin of rivers Po and Brenta, respectively, whose overall emission represents 57% of the total estimated PFAA load. Both rivers flow into the Adriatic Sea, raising concern for the marine ecosystem also because a significant PFOS load (0.3ty(-1)) is still present. Among the remaining activities, tanneries and textile industries are relevant sources of respectively PFBS and PFOA, together with short chain PFCA. As an example, the total PFAA load (0.12ty(-1)) from the textile district of Prato is equivalent to the estimated domestic emission of the whole population in all the studied basins. PMID:25108894

  17. Assessing Vulnerability under Uncertainty in the Colorado River Basin: The Colorado River Basin Water Supply and Demand Study

    NASA Astrophysics Data System (ADS)

    Jerla, C.; Adams, P.; Butler, A.; Nowak, K.; Prairie, J. R.

    2013-12-01

    Spanning parts of the seven states, of Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming, the Colorado River is one of the most critical sources of water in the western United States. Colorado River allocations exceed the long-term supply and since the 1950s, there have been a number of years when the annual water use in the Colorado River Basin exceeded the yield. The Basin is entering its second decade of drought conditions which brings challenges that will only be compounded if projections of climate change are realized. It was against this backdrop that the Colorado River Basin Water Supply and Demand Study was conducted. The Study's objectives are to define current and future imbalances in the Basin over the next 50 years and to develop and analyze adaptation and mitigation strategies to resolve those imbalances. Long-term planning in the Basin involves the integration of uncertainty with respect to a changing climate and other uncertainties such as future demand and how policies may be modified to adapt to changing reliability. The Study adopted a scenario planning approach to address this uncertainty in which thousands of scenarios were developed to encompass a wide range of plausible future water supply and demand conditions. Using Reclamation's long-term planning model, the Colorado River Simulation System, the reliability of the system to meet Basin resource needs under these future conditions was projected both with and without additional future adaptation strategies in place. System reliability metrics were developed in order to define system vulnerabilities, the conditions that lead to those vulnerabilities, and sign posts to indicate if the system is approaching a vulnerable state. Options and strategies that reduce these vulnerabilities and improve system reliability were explored through the development of portfolios. Four portfolios, each with different management strategies, were analyzed to assess their effectiveness at

  18. Morphometric analysis of the Marmara Sea river basins, Turkey

    NASA Astrophysics Data System (ADS)

    Elbaşı, Emre; Ozdemir, Hasan

    2014-05-01

    The drainage basin, the fundamental unit of the fluvial landscape, has been focus of research aimed at understanding the geometric characteristics of the master channel and its tributary network. This geometry is referred to as the basin morphometry and is nicely reviewed by Abrahams (1984). A great amount of research has focused on geometric characteristic of drainage basins, including the topology of the stream networks, and quantitative description of drainage texture, pattern, shape, and relief characteristics. Evaluation of morphometric parameters necessitates the analysis of various drainage parameters such as ordering of the various streams, measurement of basin area and perimeter, length of drainage channels, drainage density (Dd), stream frequency (Fs), bifurcation ratio (Rb), texture ratio (T), basin relief (Bh), Ruggedness number (Rn), time of concentration (Tc), hypsometric curve and integral (Hc and Hi) (Horton, 1932, Schumn, 1956, Strahler, 1957; Verstappen 1983; Keller and Pinter, 2002; Ozdemir and Bird, 2009). These morphometric parameters have generally been used to predict flood peaks, to assess sediment yield, and to estimate erosion rates in the basins. River basins of the Marmara Sea, has an area of approximately 40,000 sqkm, are the most important basins in Turkey based on their dense populations, industry and transportation systems. The primary aim of this study is to determine and analyse of morphometric characteristics of the Marmara Sea river basins using 10 m resolution Digital Elevation Model (DEM) and to evaluate of the results. For these purposes, digital 10 m contour maps scaled 1:25000 and geological maps scaled 1:100000 were used as the main data sources in the study. 10 m resolution DEM data were created using the contour maps and then drainage networks and their watersheds were extracted using D8 pour point model. Finally, linear, areal and relief morphometries were applied to the river basins using Geographic Information Systems

  19. Simulation of streamflow in small drainage basins in the southern Yampa River basin, Colorado

    USGS Publications Warehouse

    Parker, R.S.; Norris, J.M.

    1989-01-01

    Coal mining operations in northwestern Colorado commonly are located in areas that have minimal available water-resource information. Drainage-basin models can be a method for extending water-resource information to include periods for which there are no records or to transfer the information to areas that have no streamflow-gaging stations. To evaluate the magnitude and variability of the components of the water balance in the small drainage basins monitored, and to provide some method for transfer of hydrologic data, the U.S. Geological Survey 's Precipitation-Runoff Modeling System was used for small drainage basins in the southern Yampa River basin to simulate daily mean streamflow using daily precipitation and air-temperature data. The study area was divided into three hydrologic regions, and in each of these regions, three drainage basins were monitored. Two of the drainage basins in each region were used to calibrate the Precipitation-Runoff Modeling System. The model was not calibrated for the third drainage basin in each region; instead, parameter values were transferred from the model that was calibrated for the two drainage basins. For all of the drainage basins except one, period of record used for calibration and verification included water years 1976-81. Simulated annual volumes of streamflow for drainage basins used in calibration compared well with observed values; individual hydrographs indicated timing differences between the observed and simulated daily mean streamflow. Observed and simulated annual average streamflows compared well for the periods of record, but values of simulated high and low streamflows were different than observed values. Similar results were obtained when calibrated model parameter values were transferred to drainage basins that were uncalibrated. (USGS)

  20. The biogeochemistry of lipids in rivers of the Orinoco Basin

    SciTech Connect

    Jaffe, R.; Wolff, G.A.; Cabrera, A.C.

    1995-11-01

    Water samples from rivers in the Orinoco Basin were examined in order to assess the biogeochemistry of particle-associated and dissolved lipids. Lipid fractions were characterized so as to determine their origin, speciation, variability in individual rivers, and their flux to the lower Orinoco River. Aliphatic hydrocarbons, ketones, alcohols, triterpenoids, and fatty acids were ubiquitous in the rivers, and a large proportion of these compounds were found to be autochthonous in origin. The relative loadings of particle-associated and dissolved lipids were of the same order of magnitude in most of the rivers, indicating the importance of the dissolved phase. Apparently, true equilibria between water and particulate phases were not reached, probably as a result of the high amounts of colloidal and humic materials associated with the dissolved phase in most of the rivers. Preliminary data indicate that there were considerable seasonal variabilities in the distributions and concentrations of lipids in some of the rivers, but that each of these showed different behavior. 76 refs., 6 figs., 3 tabs.

  1. Generation of synthetic seasonal hydrographs for a large river basin

    NASA Astrophysics Data System (ADS)

    Karmaker, Tapas; Dutta, Subashisa

    2010-02-01

    SummaryThis paper describes a methodology for the generation of synthetic seasonal stage hydrographs with a number of flood waves for a large braided river basin based on statistical analysis of the historical stage records. The synthetic seasonal hydrographs in a river is required for different purposes such as assessing the hydraulic performances of various river training structures, morphological predictions, environmental impact analysis. The typical stage hydrograph of such a river has two components: flood waves and seasonal (monsoonal) response. Using historical stage records, flood waves in a seasonal stage record were identified and their characteristics were approximated using Maxwell distribution. The extracted characteristics of flood waves such as time of occurrence and successive flood lifts were analysed with various probability distribution function to find out their best distribution. The frequency analysis of the annual maximum flood lift was carried out. Beside this, seasonal responses were also approximated using Maxwell distribution. A relationship between the seasonal lift and total monsoonal rainfall was established. For a given total seasonal rainfall and return period of annual maximum flood wave lift, synthetic seasonal hydrograph is generated by superimposing both seasonal response and flood waves. The generated hydrographs are evaluated by comparing the cumulative frequency function of river stage and relative frequency of daily stage changes (rise/fall) for three seasons with different flood wave return periods, at two river gauging stations for the river Brahmaputra, India.

  2. The biogeochemistry of lipids in rivers of the Orinoco Basin

    NASA Astrophysics Data System (ADS)

    Jaffé, Rudolf; Wolff, George A.; Cabrera, AivléC.; Carvajal Chitty, Humberto

    1995-11-01

    Water samples from rivers in the Orinoco Basin were examined in order to assess the biogeochemistry of particle-associated and dissolved lipids. Lipid fractions were characterised so as to determine their origin, speciation, variability in individual rivers, and their flux to the lower Orinoco River. Aliphatic hydrocarbons, ketones, alcohols, triterpenoids, and fatty acids were ubiquitous in the rivers, and a large proportion of these compounds were found to be autochthonous in origin. The relative loadings of particle-associated and dissolved lipids were of the same order of magnitude in most of the rivers, indicating the importance of the dissolved phase. Apparently, true equilibria between water and particulate phases were not reached, probably as a result of the high amounts of colloidal and humic materials associated with the dissolved phase in most of the rivers. Preliminary data indicate that there were considerable seasonal variabilities in the distributions and concentrations of lipids in some of the rivers, but that each of these showed different behaviour.

  3. DOM in recharge waters of the Santa Ana River Basin

    USGS Publications Warehouse

    Leenheer, J.A.; Aiken, G.R.; Woodside, G.; O'Connor-Patel, K.

    2007-01-01

    The urban Santa Ana River in California is the primary source of recharge water for Orange County's groundwater basin, which provides water to more than two million residents. This study was undertaken to determine the unidentified portion of dissolved organic matter (DOM) in various natural surface and reclaimed waters of the Santa Ana River Basin and to assess the potential health risk of this material. The most abundant organic contaminants were anionic detergent degradation products (constituting about 12% of the DOM), which have no known adverse health effects. In addition, high percentages of dissolved colloids from bacterial cell walls were found during storm flows; these colloids foul membranes used in water treatment. Although no significant health risks were ascribed to the newly characterized DOM, the authors note that even the small amounts of humic substances deposited during storm flow periods were responsible for significant increases in disinfection by_product formation potential in these waters.

  4. [Pearl Harbor.

    ERIC Educational Resources Information Center

    Johnson, Jennifer, Ed.

    1992-01-01

    This issue of "Loblolly Magazine" was written in observance of the 50th anniversary of the U.S. entrance into World War II. The publication features interviews conducted by East Texas high school students with Clarence Otterman, one of the few survivors of the crew of the USS Arizona, which was bombed during the attack on Pearl Harbor, and with a…

  5. Characterization of Stream Morphology and Sediment Yield for the Big Black and Tombigbee River Basins, Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three segments within the Big Black River Basin, and nine within the Tombigbee River Basin are on the Mississippi 303d list of water bodies as having impaired conditions for aquatic life due to sediment. An additional 56 reaches of channel are listed for biologic impairment between the two basins. ...

  6. Mass-movement deposits in the lacustrine Eocene Green River Formation, Piceance Basin, western Colorado

    USGS Publications Warehouse

    Johnson, Ronald C.; Birdwell, Justin E.; Brownfield, Michael E.; Mercier, Tracey J.

    2015-01-01

    The Eocene Green River Formation was deposited in two large Eocene saline lakes, Lake Uinta in the Uinta and Piceance Basins and Lake Gosiute in the Greater Green River Basin. Here we will discuss mass-movement deposits in just the Piceance Basin part of Lake Uinta.

  7. Spatial heterogeneity study of vegetation coverage at Heihe River Basin

    NASA Astrophysics Data System (ADS)

    Wu, Lijuan; Zhong, Bo; Guo, Liyu; Zhao, Xiangwei

    2014-11-01

    Spatial heterogeneity of the animal-landscape system has three major components: heterogeneity of resource distributions in the physical environment, heterogeneity of plant tissue chemistry, heterogeneity of movement modes by the animal. Furthermore, all three different types of heterogeneity interact each other and can either reinforce or offset one another, thereby affecting system stability and dynamics. In previous studies, the study areas are investigated by field sampling, which costs a large amount of manpower. In addition, uncertain in sampling affects the quality of field data, which leads to unsatisfactory results during the entire study. In this study, remote sensing data is used to guide the sampling for research on heterogeneity of vegetation coverage to avoid errors caused by randomness of field sampling. Semi-variance and fractal dimension analysis are used to analyze the spatial heterogeneity of vegetation coverage at Heihe River Basin. The spherical model with nugget is used to fit the semivariogram of vegetation coverage. Based on the experiment above, it is found, (1)there is a strong correlation between vegetation coverage and distance of vegetation populations within the range of 0~28051.3188m at Heihe River Basin, but the correlation loses suddenly when the distance greater than 28051.3188m. (2)The degree of spatial heterogeneity of vegetation coverage at Heihe River Basin is medium. (3)Spatial distribution variability of vegetation occurs mainly on small scales. (4)The degree of spatial autocorrelation is 72.29% between 25% and 75%, which means that spatial correlation of vegetation coverage at Heihe River Basin is medium high.

  8. UV filters bioaccumulation in fish from Iberian river basins.

    PubMed

    Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2015-06-15

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/gd.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/gd.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04-0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. PMID:25777957

  9. Hydrogeologic data for the lower Connecticut River basin, Connecticut

    USGS Publications Warehouse

    Bingham, J.W.; Paine, F.D.; Weiss, L.A.

    1980-01-01

    This report contains geologic, ground-water, and miscellaneous data on the quality of surface water collected for a water-resources inventory of the lower Connecticut River basin, Connecticut. The study was made by the U.S. Geological Survey in fiscal cooperation with the Connecticut Department of Environmental Protection. A companion report (Connecticut Water Resources Bulletin No. 31, in preparation) interprets the factual information presented here or otherwise collected for the study.

  10. Hydrogeologic data for the lower Connecticut River basin, Connecticut

    USGS Publications Warehouse

    Bingham, J.W.; Paine, F.D.; Weiss, L.A.

    1975-01-01

    This report contains geologic, ground-water, and miscellaneous data on the quality of surface water collected for a water-resources inventory of the lower Connecticut River basin, Connecticut. The study was made by the U.S. Geological Survey in fiscal cooperation with the Connecticut Department of Environmental Protection. A companion report (Connecticut Water Resources Bulletin No. 31, in preparation) interprets the factual information presented here or otherwise collected for the study.

  11. Flood discharges in the upper Mississippi River basin, 1993

    USGS Publications Warehouse

    Parrett, Charles; Melcher, Nick B.; James, Robert W., Jr.

    1993-01-01

    Flood-peak discharges that equaled or exceeded the 10-year recurrence interval were recorded at 154 streamflow-gaging stations in the upper Mississippi River Basin. At 41 streamflowgaging stations, the peak discharge was greater than the previous maximumknown discharge. At 15 additional gaging stations, peak discharges exceeded the previous maximum regulated peak discharge. At 45 gaging stations, peak discharges exceeded 100-year recurrence intervals.

  12. The Pennsylvanian and Permian Oquirrh-Wood River basin

    SciTech Connect

    Geslin, J.K. . Dept. of Earth and Planetary Sciences)

    1993-04-01

    Strata of the Middle Pennsylvanian to Lower Permian Oquirrh-Wood River Basin (OWRB) lie unconformably above the Antler orogenic belt and flysch trough/starved basin in NW Utah, NE Nevada, and SC Idaho. Strata of the basin, now separated geographically by the Neogene Snake River Plain, show similar subsidence histories, identical mixed carbonate-siliciclastic sedimentary fill, and identical chert pebble conglomerate beds supplied by one or more DesMoinesian uplifts containing Lower Paleozoic strata. This conglomerate, of the lower Sun Valley Group, Snaky Canyon Formation, and parts of the Oquirrh Formation, was reworked progressively southward, to at least the Idaho-Utah border. It is present in strata as young as Virgilian. Virgilian to Leonardian rocks are ubiquitously fine-grained mixed carbonate-siliciclastic turbidites. These rocks contain cratonal, well-sorbed subarkosic and quartzose sand and silt in part derived from the Canadian Shield. This siliciclastic fraction is intimately mixed with arenaceous micritized skeletal material and peloids derived from an eastern carbonate platform represented by the Snaky Canyon Formation in east-central Idaho, an eastern facies of the Eagle Creek Member, Wood River Formation in the Boulder Mountains, and the Oquirrh Formation in the Deep Creek Mountains. Subsidence of the OWRB may have been caused by two phases (DesMoinesian and Wolfcampian to Leonardian) of crustal loading by continental margin tectonism to the west. An elevated rim separated the OWRB from coeval volcanogenic basins to the west. Earlier, Antler-age structures may have been reactivated. A new pulse of tectonism occurred in Leonardian to Guadalupian time as in most places carbonatic and phosphatic strata of the Leonardian to Guadalupian Park City and Phosphoria Formation overlie OWRB strata, with different geographic arrangement of basinal, slope, and shelf depocenters.

  13. 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. PMID:25142344

  14. Floodplain Organic Carbon Storage in the Central Yukon River Basin

    NASA Astrophysics Data System (ADS)

    Lininger, K.; Wohl, E.

    2014-12-01

    Floodplain storage of organic carbon is an important aspect of the global carbon cycle that is not well understood or quantified. Although it is understood that rivers transport organic carbon to the ocean, little is known about the quantity of stored carbon in boreal floodplains and the influence of fluvial processes on this storage. We present results on total organic carbon (TOC) content within the floodplains of two rivers, the Dall River and Preacher Creek, in the central Yukon River Basin in the Yukon Flats National Wildlife Refuge of Alaska. The results indicate that organic carbon storage is influenced by fluvial disturbance and grain size. The Dall River, which contains a large amount of floodplain carbon, is meandering and incised, with well-developed floodplain soils, a greater percentage of relatively old floodplain surfaces and a slower floodplain turnover time, and finer grain sizes. Preacher Creek stores less TOC, transports coarser grain sizes, and has higher rates of avulsion and floodplain turnover time. Within the floodplain of a particular river, large spatial heterogeneity in TOC content also exists as a function of depositional environment and age and vegetation community of the site. In addition, saturated regions of the floodplains, such as abandoned channels and oxbow lakes, contain more TOC compared to drier floodplain environments. Frozen alluvial soils likely contain carbon that could be released into the environment with melting permafrost, and thus quantifying the organic carbon content in the active layer of floodplain soils could provide insight into the characteristics of the permafrost beneath. The hydrology in these regions is changing due to permafrost melt, and floodplain areas usually saturated could be dried out, causing breakdown and outgassing of carbon stored in previously saturated soils. Ongoing work will result in a first-order estimate of active-layer floodplain carbon storage for the central Yukon River Basin.

  15. Can the Gila River reduce risk in the Colorado River Basin?

    NASA Astrophysics Data System (ADS)

    Wade, L. C.; Rajagopalan, B.; Lukas, J.; Kanzer, D.

    2012-12-01

    The Colorado River is the most important source of water in the southwest United States and Northern Mexico, providing water to approximately 35 million people and 4-5 million acres of irrigated lands. To manage the water resources of the basin, estimated to be about 17 million acre-feet (MAF) of undepleted supplies per year, managers use reservoir facilities that can store more than 60 MAF. As the demands on the water resources of the basin approach or exceed the average annual supply, and with average flow projected to decrease due to climate change, smart water management is vital for its sustainability. To quantify the future risk of depleting reservoir storage, Rajagopalan et al. (2009) developed a water-balance model and ran it under scenarios based on historical, paleo-reconstructed and future projections of flows, and different management alternatives. That study did not consider the impact of the Gila River, which enters the Colorado River below all major reservoirs and U.S. diversions. Due to intensive use in Central Arizona, the Gila only has significant inflows to the Colorado in wet years. However, these irregular inflows could beneficially influence system reliability in the US by helping to meet a portion of the 1.5 MAF delivery obligations to Mexico. To help quantify the potential system reliability benefit of the Gila River, we modify the Rajagopalan et al (2009) model to incorporate simulated Gila River inflows. These new data inputs to the water balance model are based on historical flows and tree-ring reconstructions of flow in the Upper Colorado River Basin (at Lee's Ferry), the Lower Colorado River Basin (tributary inflows), and the intermittent flows from the Gila River which are generated using extreme value analysis methods. Incorporating Gila River inflows, although they are highly variable and intermittent, reduces the modeled cumulative risk of reservoir depletion by 4 to 11% by 2057, depending on the demand schedule, reservoir operation

  16. Detecting runoff variation in Weihe River basin, China

    NASA Astrophysics Data System (ADS)

    Jingjing, F.; Qiang, H.; Shen, C.; Aijun, G.

    2015-05-01

    Dramatic changes in hydrological factors in the Weihe River basin are analysed. These changes have exacerbated ecological problems and caused severe water shortages for agriculture, industries and the human population in the region, but their drivers are uncertain. The Mann-Kendall test, accumulated departure analysis, sequential clustering and the sliding t-test methods were used to identify the causes of changes in precipitation and runoff in the Weihe basin. Change-points were identified in the precipitation and runoff records for all sub-catchments. For runoff, the change in trend was most pronounced during the 1990s, whereas changes in precipitation were more prominent earlier. The results indicate that human activities have had a greater impact than climate change on the hydrology of the Weihe basin. These findings have significant implications for the establishment of effective strategies to counter adverse effects of hydrological changes in the catchment.

  17. Integrated Regional Assessment of Climate Change for Korean River Basins

    NASA Astrophysics Data System (ADS)

    Chang, H.; Franczyk, J.; Bae, D.; Jung, I.; Kwon, W.; Im, E.

    2006-12-01

    As the first national assessment, we investigated the potential impacts of climate change on water resources in the Korean peninsula that has varying climates and complex topography. Together with the precipitation runoff modeling system model, we used high resolution climate change scenarios and population and industrial growth scenarios for 2030. Climate change alone is projected to decrease mean annual runoff by 10% in four major river basins located in southern Korea. Summer floods and spring droughts are likely to occur more frequently at the sub-basin scale, suggesting the increasing vulnerability of regional water resources to climate change. When climate change scenarios are combined with population and industrial growth scenarios, the geographical variations of water stress increased. This necessitates the need for water allocation among different water users under the changing environment. A tool is being developed to address optimizing water allocation under changes in water availability for a selected basin of Korea.

  18. Flood tracking chart for the Illinois River basin

    USGS Publications Warehouse

    Avery, Charles F.; Holmes, Jr., Robert R.; Sharpe, Jennifer B.

    1998-01-01

    This Flood Tracking Chart for the Illinois River Basin in Illinois can be used to record and compare the predicted or current flood-crest stage to past flood-crest information. This information can then be used by residents and emergency-response personnel to make informed decisions concerning the threat of flooding to life and property. The chart shows a map of the Illinois River Basin (see below), the location of real-time streamflow-gaging stations in the basin, graphs of selected historical recorded flood-crest stages at each of the stations, and sea-level conversion (SLC) factors that allow conversion of the current or predicted flood-crest stage to elevation above sea level. Each graph represents a streamflow-gaging station and has a space to record the most current river stage reported for that station by the U.S. Geological Survey (USGS). The National Weather Service (NWS) predicts flood crests for many of the stations shown on this chart.

  19. The lower Miocene Liuhua carbonate reservoir, Pearl River Mouth basin, offshore People's Republic of China

    SciTech Connect

    Turner, N.L. )

    1990-06-01

    Since the drilling in January 1987 of the Amoco Liuhua 11-1-1A discovery well located 220 km southeast of Hong Kong, five additional wells have drilled and tested this lower Miocene Zhujiang Formation carbonate reservoir. Deposition of upper Zhujiang carbonates in the Liuhua area took place in an isolated platform environment. Major facies are (1) a platform-rim reef composed of red algae and coral boundstones, (2) a back-reef lagoon of fine-grained carbonates, (3) a large interior platform bank dominated by red algae but with a red algal-coral fringe on the south and southwest sides, (4) platform grainrocks, and (5) platform to lagoonal mud-supported carbonates. A paleo-water table surface present in every well represents a time of regional exposure. The reservoir is subdivided into five diagenetic carbonate units that are correlated across the platform and that cross facies boundaries and inferred time lines. The uppermost unit is a thin, tightly cemented carbonate formed at the time of drowning of the platform. Two thick highly leached carbonate units with porosities and permeabilities as high as 30% and several darcys comprise most of the reservoir. They are separated by a thin (7 m) tighter interval that formed by cementation below the water table of an exposure surface. The less porous unit at the base of the reservoir formed as a result of interaction between oil and water causing calcite cementation. Leaching continued in the carbonate below the reservoir and biodegradation occurred after oil had filled the structure. Further drilling and testing will determine the limits of the diagenetic units and whether the reservoir has commercial potential.

  20. Suspended sediment dynamics in the Mississippi River basin

    NASA Astrophysics Data System (ADS)

    Ali, K.; Cullis, J. D.; Xu, X.; More, M.; Hassan, M. A.; Simon, A.; Donner, S. D.; Sivapalan, M.

    2010-12-01

    This study investigated sediment trends in a heavily managed basin influenced by substantial human impacts. Spatial and temporal patterns of suspended sediment dynamics were examined in the Mississippi River basin by utilizing all available USGS suspended-sediment data with a minimum of 30 matching samples of suspended-sediment concentration and water discharge. These spatial trends were related to the land use change which has occurred over the last century and this includes dams, soil conservation measures and channelization. Sediment sources and sinks along the main stem of the Mississippi River and its main tributaries were identified and mapped. Three main trends were identified. 1) Sediment yields decreasing with increasing drainage area imply systematically increasing sediment storage downstream the landscape. 2) Sediment yields increasing with drainage area indicate net recruitment of sediment along the main valleys from banks and floodplain erosion. 3) Sediment yields showing no relationship with drainage area are attributed to the complexity arising from diverse climate, geology and land use of the basin. Based on the results, regional scale sediment yield maps were prepared and linked to the land use and the history of the basin.

  1. 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.

  2. Fecal steroids in riverine runoff of the Pearl River Delta, South China: levels, potential sources and inputs to the coastal ocean.

    PubMed

    Wang, Ji-Zhong; Guan, Yu-Feng; Ni, Hong-Gang; Liu, Gui-Jian; Zeng, Eddy Y

    2010-01-01

    Domestic sewage is a potential source of contamination deteriorating water quality in rivers and coastal environments. The present study determined the concentrations of eight steroids in both filtrate and suspended particulate matter (SPM) samples collected monthly at the eight major riverine runoff outlets of the Pearl River Delta (PRD), South China, from March 2005 to February 2006. The concentration of the eight steroids (sum of which is defined as Sigma(8)steroid) in the filtrate and SPM samples ranged 16.7-1340 ng L(-1) and 0.44-240 microg g(-1), respectively. The filtrate samples contained the highest levels of cholesterol (CHOE) and stigmasterol (STIG) on average, whereas the SPM samples had the largest relative abundances of CHOE and coprostanol (COP). In general, larger proportions of the steroids were associated with SPM than with the filtrate phase. The combined (filtrate plus SPM) concentrations of COP in riverine runoff of the PRD were at the midpoint of the global range in surface water. The concentrations of Sigma(8)steroid and COP in SPM were not significantly correlated with particulate organic carbon (POC), riverine runoff, or SPM concentrations, which indicates the dominance of nonpoint input sources for the occurrence of steroids in the PRD. The annual riverine inputs of Sigma(8)steroid and COP were estimated at 360 and 31.6 tons yr(-1), respectively, and the monthly inputs of both Sigma(8)steroid and COP were positively correlated with monthly runoff discharge. Furthermore, the concentrations of Sigma(8)steroid, COP, and CHOE showed significant temporal and spatial variability. These results can be explained by a combination of climatic characteristics, socioeconomic conditions, and steroid sources. Analyses of the diagnostic indices of COP and background information suggested that riverine runoff from the PRD may have been affected by domestic wastewater, which appeared to be a major COP source to the Pearl River Estuary and South China Sea

  3. Anacostia River Basin: Large, Medium, and Small Lumps

    NASA Astrophysics Data System (ADS)

    Feldman, A. D.; Dufour, A.; Dotson, H. W.

    2001-05-01

    The Hydrologic Engineering Center, HEC, is performing a hydrologic analysis of the Anacostia River Basin in support of flood-damage-reduction studies there by the U.S. Army Corps of Engineers' Baltimore District. The main objective is to determine the best estimate of flow-exceedance-probability functions at several flood-damage-index locations in the basin. Thus, a generalized methodology for determining flow-frequency curves anywhere in the basin was developed. Three methodologies were used to make best estimates of the flow-frequency curves: watershed-runoff computer simulation modeling, statistical analysis of stream-gauge records, and application of USGS regional regression equations. This paper addresses the watershed-modeling portion of the study. The Anacostia River Basin originates in Maryland and consists of two primary tributaries: the Northwest Branch, 128 sq km at the Hyattsville gauge, and the Northeast Branch, 188 sq km at the Riverdale gauge. After the confluence a short distance downstream, it flows south into eastern Washington, D.C., and the Potomac River. The basins were mostly rural until the 1960's when the D.C.-area urbanization spread from west to east. The streamflow gauges have been in operation since 1939 and precipitation gauges since 1948. The hydrologic model is key to several aspects of such an investigation. Calibrating a hydrologic model helps the engineer understand the precipitation-runoff processes in the basin. Simulating frequency-based storm runoff, e.g., NWS TP-40 with commensurate initial moisture conditions, is an estimate of a like-frequency flow. Simulating key historical storms with current land-use conditions can be used to adjust non-stationary (due to urbanization) gauged annual peak flows. Simulating frequency-based storms, with a model calibrated to a best-estimate flow-frequency curve, can be used to estimate flow frequencies anywhere in the basin for existing and future land-use conditions. The watershed model was

  4. Hydrological Cycle in the Heihe River Basin and Its Implication for Water Resource Management in Inland River Basins (Invited)

    NASA Astrophysics Data System (ADS)

    Li, X.; Cheng, G.; Tian, W.; Zhang, Y.; Zhou, J.; Pan, X.; Ge, Y.; Hu, X.

    2013-12-01

    Inland river basins take about 11.4% of the land area of the world and most of them are distributed over arid regions. Understanding the hydrological cycle of inland river basin is important for water resource management in water scarcity regions. This paper illustrated hydrological cycle of a typical inland river basin in China, the Heihe River Basin (HRB). First, water balance in upper, middle and lower reaches of the HRB was conceptualized by analyzing dominant hydrological processes in different parts of the river basin. Then, we used a modeling approach to study the water cycle in the HRB. In the upper reaches, we used the GBHM-SHAW, a distributed hydrological model with a new frozen soil parameterization. In the middle and lower reaches, we used the GWSiB, a three-dimensionally coupled land surface-groundwater model. Modeling results were compared with water balance observations in different landscapes and cross-validated with other results to ensure the reliability. The results show that the hydrological cycle in HRB has some distinctive characteristics. Mountainous area generates almost all of the runoff for the whole river basin. High-elevation zones have much larger runoff/precipitation ratio. Cryospheric hydrology plays an important role. Although snow melting and glacier runoff take less than 25% of total runoff, these processes regulate inter-annual variation of runoff and thus provide stable water resource for oases downstream. Forest area contributes almost no runoff but it smoothes runoff and reduces floods by storing water in soil and releasing it out slowly. In the middle reaches, artificial hydrological cycle is much more dominated than natural one. River water and groundwater, recharged by runoff from mountainous area, is the water resource to support the agriculture and nurture the riparian ecosystem. Precipitation, approximately 150 mm in average, is only a supplement to agriculture use but sufficient to sustain desert vegetation. Water

  5. Basin-wide architecture of sandstone reservoirs in the Fort Union Formation, Wind River basin, Wyoming

    SciTech Connect

    Flores, R.M.; Keighin, C.W.; Keefer, W.R. )

    1991-06-01

    Architecture of hydrocarbon-bearing sandstone reservoirs of the Paleocene Fort Union Formation in the Wind River basin, Wyoming, was studied using lithofacies, grain size, bounding surfaces, sedimentary structures, internal organization, and geometry. Two principal groups of reservoirs, both erosionally based and fining upward, consist of either conglomeratic sandstone or sandstone lithofacies. Two types of architecture were recognized in conglomeratic sandstone reservoirs: (1) heterogeneous, multistacked, lenticular and (2) homogeneous, multiscoured, wedge-sheet bodies. Three types of architecture were recognized in sandstone reservoirs: (3) heterogeneous, multistacked, elongate; (4) homogeneous, multilateral, lenticular; and (5) homogeneous, ribbon-lensoid bodies. Conglomeratic sandstone reservoirs in the southern and southwestern parts of the basin suggest deposition in gravel-bedload fluvial systems influenced by provenance uplift of the Granite and southern Wind River mountains. Type 2 reservoirs represent deposits of eastward-flowing braided streams aggrading an alluvial valley in response to base level rise. Thus, to determine basin-wide architecture of reservoirs requires understanding the interplay between base level conditions, basin subsidence, and provenance uplift. These interrelated factors, in turn, control differences in hierarchies of fluvial systems throughout the basin.

  6. Integrated Basin Scale Hydropower and Environmental Opportunity Assessment in the Deschutes River Basin, Oregon

    NASA Astrophysics Data System (ADS)

    Voisin, N.; Geerlofs, S. H.; Vail, L. W.; Ham, K. D.; Tagestad, J. D.; Hanrahan, T. P.; Seiple, T. E.; Coleman, A. M.; Stewart, K.

    2012-04-01

    The Deschutes River Basin in Oregon, USA, is home to a number of diverse groups of stakeholders that rely upon the complex snowmelt and groundwater-dominated river system to support their needs, livelihoods, and interests. Basin system operations that vary across various temporal and spatial scales often must balance an array of competing demands including maintaining adequate municipal water supply, recreation, hydropower generation, regulations related to environmental flows, mitigation programs for salmon returns, and in-stream and storage rights for irrigation water supplied by surface water diversions and groundwater pumping. The U.S. Department of Energy's Integrated Basin-scale Opportunity Assessment initiative is taking a system-wide approach to identifying opportunities and actions to increase hydropower and enhance environmental conditions while sustaining reliable supply for other uses. Opportunity scenarios are analyzed in collaboration with stakeholders, through nested integrated modeling and visualization software to assess tradeoffs and system-scale effects. Opportunity assessments are not intended to produce decisional documents or substitute for basin planning processes; assessments are instead intended to provide tools, information, and a forum for catalyzing conversation about scenarios where both environmental and hydropower gains can be realized within a given basin. We present the results of the nested integrated modeling approach and the modeling scenarios in order to identify and explore opportunities for the system.

  7. Development of streamflow projections under changing climate conditions over Colorado River basin headwaters

    NASA Astrophysics Data System (ADS)

    Miller, W. P.; Piechota, T. C.; Gangopadhyay, S.; Pruitt, T.

    2011-07-01

    The current drought over the Colorado River Basin has raised concerns that the US Department of the Interior, Bureau of Reclamation (Reclamation) may impose water shortages over the lower portion of the basin for the first time in history. The guidelines that determine levels of shortage are affected by relatively short-term (3 to 7 month) forecasts determined by the Colorado Basin River Forecast Center (CBRFC) using the National Weather Service (NWS) River Forecasting System (RFS) hydrologic model. While these forecasts by the CBRFC are useful, water managers within the basin are interested in long-term projections of streamflow, particularly under changing climate conditions. In this study, a bias-corrected, statistically downscaled dataset of projected climate is used to force the NWS RFS utilized by the CBRFC to derive projections of streamflow over the Green, Gunnison, and San Juan River headwater basins located within the Colorado River Basin. This study evaluates the impact of changing climate to evapotranspiration rates and contributes to a better understanding of how hydrologic processes change under varying climate conditions. The impact to evapotranspiration rates is taken into consideration and incorporated into the development of streamflow projections over Colorado River headwater basins in this study. Additionally, the NWS RFS is modified to account for impacts to evapotranspiration due to changing temperature over the basin. Adjusting evapotranspiration demands resulted in a 6 % to 13 % average decrease in runoff over the Gunnison River Basin when compared to static evapotranspiration rates. Streamflow projections derived using projections of future climate and the NWS RFS provided by the CBRFC resulted in decreased runoff in 2 of the 3 basins considered. Over the Gunnison and San Juan River basins, a 10 % to 15 % average decrease in basin runoff is projected through the year 2099. However, over the Green River basin, a 5 % to 8 % increase in basin

  8. Rivers at Risk: An Activity Based Study Guide for the Colorado River Basin.

    ERIC Educational Resources Information Center

    Samples, Bob, Ed.

    This activity guide is intended to increase student awareness and understanding about the Colorado River Basin. Each activity includes objectives, procedures, materials list, related activities, questions for students, and related information. The activities are varied to appeal to a wide range of learning styles and modalities and are…

  9. SAVANNAH RIVER SITE R REACTOR DISASSEMBLY BASIN IN SITU DECOMMISSIONING

    SciTech Connect

    Langton, C.; Blankenship, J.; Griffin, W.; Serrato, M.

    2009-12-03

    The US DOE concept for facility in-situ decommissioning (ISD) is to physically stabilize and isolate in tact, structurally sound facilities that are no longer needed for their original purpose of, i.e., generating (reactor facilities), processing(isotope separation facilities) or storing radioactive materials. The 105-R Disassembly Basin is the first SRS reactor facility to undergo the in-situ decommissioning (ISD) process. This ISD process complies with the105-R Disassembly Basin project strategy as outlined in the Engineering Evaluation/Cost Analysis for the Grouting of the R-Reactor Disassembly Basin at the Savannah River Site and includes: (1) Managing residual water by solidification in-place or evaporation at another facility; (2) Filling the below grade portion of the basin with cementitious materials to physically stabilize the basin and prevent collapse of the final cap - Sludge and debris in the bottom few feet of the basin will be encapsulated between the basin floor and overlying fill material to isolate if from the environment; (3) Demolishing the above grade portion of the structure and relocating the resulting debris to another location or disposing of the debris in-place; and (4) Capping the basin area with a concrete slab which is part of an engineered cap to prevent inadvertent intrusion. The estimated total grout volume to fill the 105-R Reactor Disassembly Basin is 24,424 cubic meters or 31,945 cubic yards. Portland cement-based structural fill materials were design and tested for the reactor ISD project and a placement strategy for stabilizing the basin was developed. Based on structural engineering analyses and work flow considerations, the recommended maximum lift height is 5 feet with 24 hours between lifts. Pertinent data and information related to the SRS 105-R-Reactor Disassembly Basin in-situ decommissioning include: regulatory documentation, residual water management, area preparation activities, technology needs, fill material designs

  10. Sediment budget in the Ucayali River basin, an Andean tributary of the Amazon River

    NASA Astrophysics Data System (ADS)

    Santini, W.; Martinez, J.-M.; Espinoza-Villar, R.; Cochonneau, G.; Vauchel, P.; Moquet, J.-S.; Baby, P.; Espinoza, J.-C.; Lavado, W.; Carranza, J.; Guyot, J.-L.

    2015-03-01

    Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in the upper Ucayali basin are rapid, favoured by a marked seasonality in this region and extreme precipitation cells above sedimentary strata, uplifted during Neogene times by a still active sub-Andean tectonic thrust. Around 40% of those sediments are trapped in the Ucayali retro-foreland basin system. Recent advances in remote sensing for Amazonian large rivers now allow us to complete the ground hydrological data. In this work, we propose a first estimation of the erosion and sedimentation budget of the Ucayali River catchment, based on spatial and conventional HYBAM Observatory network.

  11. Sources of nitrate yields in the Mississippi River Basin.

    PubMed

    David, Mark B; Drinkwater, Laurie E; McIsaac, Gregory F

    2010-01-01

    Riverine nitrate N in the Mississippi River leads to hypoxia in the Gulf of Mexico. Several recent modeling studies estimated major N inputs and suggested source areas that could be targeted for conservation programs. We conducted a similar analysis with more recent and extensive data that demonstrates the importance of hydrology in controlling the percentage of net N inputs (NNI) exported by rivers. The average fraction of annual riverine nitrate N export/NNI ranged from 0.05 for the lower Mississippi subbasin to 0.3 for the upper Mississippi River basin and as high as 1.4 (4.2 in a wet year) for the Embarras River watershed, a mostly tile-drained basin. Intensive corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] watersheds on Mollisols had low NNI values and when combined with riverine N losses suggest a net depletion of soil organic N. We used county-level data to develop a nonlinear model ofN inputs and landscape factors that were related to winter-spring riverine nitrate yields for 153 watersheds within the basin. We found that river runoff times fertilizer N input was the major predictive term, explaining 76% of the variation in the model. Fertilizer inputs were highly correlated with fraction of land area in row crops. Tile drainage explained 17% of the spatial variation in winter-spring nitrate yield, whereas human consumption of N (i.e., sewage effluent) accounted for 7%. Net N inputs were not a good predictor of riverine nitrate N yields, nor were other N balances. We used this model to predict the expected nitrate N yield from each county in the Mississippi River basin; the greatest nitrate N yields corresponded to the highly productive, tile-drained cornbelt from southwest Minnesota across Iowa, Illinois, Indiana, and Ohio. This analysis can be used to guide decisions about where efforts to reduce nitrate N losses can be most effectively targeted to improve local water quality and reduce export to the Gulf of Mexico. PMID:21043271

  12. Framework for Assessing Water Resource Sustainability in River Basins

    NASA Astrophysics Data System (ADS)

    Borden, J.; Goodwin, P.; Swanson, D.

    2013-12-01

    As the anthropogenic footprint increases on Earth, the wise use, maintenance, and protection of freshwater resources will be a key element in the sustainability of development. Borne from efforts to promote sustainable development of water resources is Integrated Water Resource Management (IWRM), which promotes efficiency of water resources, equity in water allocation across different social and economic groups, and environmental sustainability. Methodologies supporting IWRM implementation have largely focused on the overall process, but have had limited attention on the evaluation methods for ecologic, economic, and social conditions (the sustainability criterion). Thus, assessment frameworks are needed to support the analysis of water resources and evaluation of sustainable solutions in the IWRM process. To address this need, the River Basin Analysis Framework (RBAF) provides a structure for understanding water related issues and testing the sustainability of proposed solutions in river basins. The RBAF merges three approaches: the UN GEO 4 DPSIR approach, the Millennium Ecosystem Assessment approach, and the principles of sustainable development. Merging these approaches enables users to understand the spatiotemporal interactions between the hydrologic and ecologic systems, evaluate the impacts of disturbances (drivers, pressures) on the ecosystem goods and services (EGS) and constituents of human well-being (HWB), and identify and employ analytical methods and indicators in the assessments. The RBAF is comprised of a conceptual component (RBAF-C) and an analytical component (RBAF-A). For each disturbance type, the RBAF-C shows the potential directional change in the hydrologic cycle (peak flows, seasonality, etc.), EGS (drinking water supply, water purification, recreational opportunities, etc.), and HWB (safety, health, access to a basic materials), thus allowing users insight into potential impacts as well as providing technical guidance on the methods and

  13. Soil erosion in river basins of Georgia

    NASA Astrophysics Data System (ADS)

    Gogichaishvili, G. P.

    2016-06-01

    The area of cultivated lands in western and eastern Georgia comprises 28-40 and 29-33% of the total catchment areas, respectively. Eroded arable soils in Georgia occupy 205700 ha, i.e. 30.5% of the total plowland area, including 110500 ha (16.4%) of slightly eroded soils, 74400 ha (11%) of moderately eroded soils, and 20800 ha (3.1%) of strongly eroded soils. The maximum denudation rate in catchments of western Georgia reaches 1.0 mm/yr. The minimum denudation (0.01 mm/yr.) is typical of river catchments in southern Georgia. The mean annual soil loss from plowed fields in western Georgia reaches 17.4 t/ha and exceeds the soil loss tolerance by nearly four times. In eastern Georgia, it is equal to 10.46 t/ha and exceeds the soil loss tolerance by 2.5 times. In southern Georgia, the mean annual soil loss from plowed fields is as low as 3.08 t per ha, i.e., much lower than the soil loss tolerance.

  14. Episodic Emplacement of Sediment + Carbon within Large Tropical River Basins

    NASA Astrophysics Data System (ADS)

    Aalto, R.; Aufdenkampe, A.

    2012-04-01

    Application of advanced methods for imaging (sub-bottom sonar and ERGI), dating (high resolution 210-Pb and 14-C from deep cores), and biogeochemical analysis have facilitated the characterization and inter-comparison of floodplain sedimentation rates, styles, and carbon loading across disparate large river basins. Two examples explored here are the near-pristine 72,000 km2 Beni River basin in northern Bolivia and the similarly natural 36,000 km2 Strickland River basin in Papua New Guinea - that are located on either side of the Equatorial Pacific warm pool that drives the ENSO phenomenon. Our published research suggests that large, rapid-rise, cold-phase ENSO floods account for the preponderance of sediment accumulation within these two tropical systems. New results to be presented at EGU further clarify the extent of modern deposits (~100 yrs) within both systems and add a deeper perspective into how these extensive floodplains developed over the Holocene, both in response to external forcing (climate and base level) and internal system morphodynamics. The vast scale of these temporally discrete deposits (typically 100s of millions of tonnes over relatively short time periods) involved equate to high burial rates, which in turn support the high carbon loadings sequestered within the resulting sedimentary deposits. We have identified the principal source of this carbon and sedimentary material to be extensive landslides throughout the high-relief headwaters - failures that deliver huge charges of pulverized rock and soil directly into canyons (in both the Bolivian Andes and the PNG Highlands), where raging floodwaters provide efficient transport to lowland depocentres. We present recent results from our research in these basins, providing insight into the details of such enormous mass budgets that result in a signicant carbon sink within the floodplains. Processes, timing, and rates are compared between the two systems, providing insight into the nature of

  15. Energy development and water options in the Yellowstone River Basin

    SciTech Connect

    Narayanan, R.; MacIntyre, D.D.; Torpy, M.F.

    1980-08-01

    Using a mixed-integer programming model, the impacts of institutional constraints on the marginal capacity for energy development in the Yellowstone River Basin and consequent hydrologic changes were examined. Under average annual flow conditions, energy outputs in the Yellowstone Basin can increase roughly nine times by 1985 and 12 to 18 times by 2000. In contrast, water availability is limiting energy development in the Tongue and Powder River Basins in Wyoming. Variability in hydrologic regime causes model solutions to change drastically. If flows decrease to 80 and 60% of average annual levels, the energy production is decreased by 17 and 95%, respectively. If development strategies in the basin are followed on the basis of 80% average annual flows, the Buffalo Bill enlargement (271,300 acre-ft), Tongue River Modification (58,000 acre-ft), and the two reservoirs at Sweetgrass Creek (each 27,000 acre-ft) will be necessary, in addition to several small storage facilities, to best meet the instream flow needs in Montana and to deliver the waters apportioned by compact between Wyoming and Montana. Furthermore, the results indicate that relaxing the instream flow requirements from recommended levels by 10% could increase regional energy output by 19% in 1985 and 35% in 2000. This model illustrates that modifications in institutional restrictions to achieve greater water mobility between users in a given state, as well as flexible practices for transferring water between states, can assist economic growth. Thus, the probability for restricted energy development at this juncture appears to be affected to a greater degree by institutional constraints than by water availability constraints.

  16. Long Term Discharge Estimation for Ogoué River Basin

    NASA Astrophysics Data System (ADS)

    Seyler, F.; Linguet, L.; Calmant, S.

    2014-12-01

    Ogoué river basin is one the last preserved tropical rain forest basin in the world. The river basin covers about 75% of Gabon. Results of a study conducted on wall-to wall forest cover map using Landsat images (Fichet et al., 2014) gave a net forest loss of 0,38% from 1990 and 2000 and sensibly the same loss rate between 2000 and 2010. However, the country launched recently an ambitious development plan, with communication infrastructure, agriculture and forestry as well as mining projects. Hydrological cycle response to changes may be expected, in both quantitative and qualitative aspects. Unfortunately monitoring gauging stations have stopped functioning in the seventies, and Gabon will then be unable to evaluate, mitigate and adapt adequately to these environmental challenges. Historical data were registered during 42 years at Lambaréné (from 1929 to 1974) and during 10 to 20 years at 17 other ground stations. The quantile function approach (Tourian et al., 2013) has been tested to estimate discharge from J2 and ERS/Envisat/AltiKa virtual stations. This is an opportunity to assess long term discharge patterns in order to monitor land use change effects and eventual disturbance in runoff. Figure 1: Ogoué River basin: J2 (red) and ERS/ENVISAT/ALTIKa (purple) virtual stations Fichet, L. V., Sannier, C., Massard Makaga, E. K., Seyler, F. (2013) Assessing the accuracy of forest cover map for 1990, 2000 and 2010 at national scale in Gabon. In press IEEE Journal of Selected Topics in Applied Earth Observations and Remote SensingTourian, M. J., Sneeuw, N., & Bárdossy, A. (2013). A quantile function approach to discharge estimation from satellite altimetry (ENVISAT). Water Resources Research, 49(7), 4174-4186. doi:10.1002/wrcr.20348

  17. Groundwater quality in the Chemung River, Eastern Lake Ontario, and Lower Hudson River Basins, New York, 2013

    USGS Publications Warehouse

    Scott, Tia-Marie; Nystrom, Elizabeth A.; Reddy, James E.

    2015-01-01

    The Lower Hudson River Basin study area covers 5,607 square miles and encompasses the part of the Lower Hudson River Basin that lies within New York plus the parts of the Housatonic, Hackensack, Bronx, and Saugatuck River Basins that are in New York. Twelve of the wells sampled in the Lower Hudson River Basin are completed in sand-and-gravel deposits, and 13 are completed in bedrock. Groundwater in the Lower Hudson River Basin was generally of good quality, although properties and concentrations of some constituents—pH, sodium, chloride, dissolved solids, arsenic, aluminum, iron, manganese, radon-222, total coliform bacteria, fecal coliform bacteria, Escherichia coli bacteria, and heterotrophic plate count—equaled or exceeded primary, secondary, or proposed drinking-water standards. The constituent most frequently detected in concentrations exceeding drinking-water standards (20 of 25 samples) was radon-222.

  18. Perfluoroalkyl substances in the Ebro and Guadalquivir river basins (Spain).

    PubMed

    Lorenzo, María; Campo, Julián; Farré, Marinella; Pérez, Francisca; Picó, Yolanda; Barceló, Damià

    2016-01-01

    Mediterranean rivers are characteristically irregular with changes in flow and located in high population density areas. This affects the concentration of pollutants in the aquatic environments. In this study, the occurrence and sources of 21 perfluoroalkyl substances (PFASs) were determined in water, sediment and biota of the Ebro and Guadalquivir river basins (Spain). In water samples, of 21 analytes screened, 11 were found in Ebro and 9 in Guadalquivir. In both basins, the most frequents were PFBA, PFPeA and PFOA. Maximum concentration was detected for PFBA, up to 251.3 ng L(-1) in Ebro and 742.9 ng L(-1) in Guadalquivir. Regarding the sediments, 8 PFASs were detected in the samples from Ebro and 9 in those from Guadalquivir. The PFASs most frequently detected were PFBA, PFPeA, PFOA and PFOS. Maximum concentration in Ebro samples was, in dry weight, for PFOA (32.3 ng g(-1)) and in Guadalquivir samples for PFBA (63.8 ng g(-1)). For biota, 12 PFASs were detected in fish from the Ebro River and only one (PFOS) in that from Guadalquivir. In the Ebro basin, the most frequents were PFBA, PFHxA, PFOA, PFBS, PFOS and PFOSA. Maximum concentration in Ebro samples was, in wet weight, for PFHxA with 1280.2 ng g(-1), and in Guadalquivir samples for PFOS with 79.8 ng g(-1). These compounds were detected in the whole course of the rivers including the upper parts. In some points contamination was due to point sources mostly related to human activities (e.g. ski resorts, military camps, urban areas.). However, there are also some areas clearly affected by diffuse sources as atmospheric deposition. PMID:26250865

  19. Estimating flows in ungauged river basins in northern Mozambique

    NASA Astrophysics Data System (ADS)

    Minihane, M.

    2011-12-01

    In many regions across the globe, there are limited streamflow observations and therefore limited knowledge of availability of surface water resources. In many cases, these rivers lie in countries that would benefit from economic development and improved access to water and sanitation services, both of which are linked to water resources. Additional information about streamflow in these watersheds is critical to water resources planning and economic development strategies. In southeastern Africa, the remote Rovuma River lies on the border between Mozambique and Tanzania. There are limited historic measurements in the main tributary and no recent observations. Improved knowledge of the water resource availability and inter-annual variability of the Rovuma River will enhance transboundary river basin management discussions for this river basin. While major rivers farther south in the country are more closely monitored, those in the north have gauging stations with only scattered observations and have not been active since the early 1980's. Reliable estimates of historic conditions are fundamental to water resources planning. This work aims to provide estimates in these rivers and to quantify uncertainty and bounds on those estimates. A combination of methods is used to estimate historic flows: simple index gauge methods such as the drainage area ratio method and mean flow ratio method, a statistical regression method, a combination of an index gauge method and global gridded runoff data, and a hydrological model. These results are compared to in-situ streamflow estimates based on stage measurements and rating curves for the basins and time frames for which data is available. The evaluation of the methods is based on an efficiency ratio, bias, and representation of seasonality and inter-annual variability. Use of gridded global datasets, either with the mean flow ratio method or a hydrological model, appears to provide improved estimates over use of local observations

  20. Summary of the river-quality assessment of the upper Chattahoochee River basin, Georgia

    USGS Publications Warehouse

    Cherry, R.N.; Faye, R.E.; Stamer, J.K.; Kleckner, R.L.

    1980-01-01

    The river-quality assessment of the Upper Chattahoochee River Basin included studies of (1) the impact of heat loads on river quality, (2) sediment transport and deposition, (3) magnitude and nature of point and nonpoint discharges, and (4) phytoplankton growth in the river and reservoirs. The combined thermal effects of flow regulation and powerplants effluents resulted in mean daily river temperature downstream of the powerplants about equal to or less than computed natural temperatures. The average annual river temperature in 1976 was 14.0 ? Celsius just upstream of the Atkinson-McDonough thermoelectric powerplants and 16.0 ? Celsius just downstream from the powerplants. During a low-flow period in June 1977 the heat load from the two powerplants caused an increase in river temperatures of about 7 ? Celsius and a subsequent decrease in the dissolved-oxygen concentration of about 0.2 milligrams per liter. During the June low-flow period, point sources contributed 63 percent of the ultimate biochemical oxygen demand and 97 percent of ammonium as nitrogen at the Franklin station. Oxidation of ultimate biochemical demand and ammonium caused dissolved-oxygen concentrations to decrease from about 8.0 milligrams per liter at river mile 299 to about 4.5 milligrams per liter at river mile 271. Dissolved orthophosphate is the nutrient presently limiting phytoplankton growth in the West Point Lake when water temperatures are greater than about 26 ? Celsius.

  1. Development of streamflow projections under changing climate conditions over Colorado River Basin headwaters

    NASA Astrophysics Data System (ADS)

    Miller, W. P.; Piechota, T. C.; Gangopadhyay, S.; Pruitt, T.

    2010-08-01

    The current drought over the Colorado River Basin has raised concerns that the US Department of the Interior, Bureau of Reclamation (Reclamation) may impose water shortages over the lower portion of the basin for the first time in history. The guidelines that determine levels of shortage are affected by forecasts determined by the Colorado Basin River Forecast Center (CBRFC). While these forecasts by the CBRFC are useful, water managers within the basin are interested in long-term projections of streamflow, particularly under changing climate conditions. In this study, a bias-corrected, statistically downscaled dataset of projected climate is used to force a hydrologic model utilized by the CBRFC to derive projections of streamflow over the Green, Gunnison, and San Juan River headwater basins located within the Colorado River Basin. This study evaluates the impact of changing climate to evapotranspiration rates. The impact to evapotranspiration rates is taken into consideration and incorporated into the development of streamflow projections over Colorado River headwater basins in this study. Additionally, the CBRFC hydrologic model is modified to account for impacts to evapotranspiration due to changing temperature over the basin. Adjusting evapotranspiration demands over the Gunnison resulted in a 6% to 13% average decrease in runoff over the Gunnison River Basin when compared to static evapotranspiration rates. Streamflow projections derived using projections of future climate and the CBRFC's hydrologic model resulted in decreased runoff in 2 of the 3 basins considered. Over the Gunnison and San Juan River basins, a 10% to 15% average decrease in basin runoff is projected through the year 2099. However, over the Green River basin, a 5% to 8% increase in basin runoff is projected through 2099. Evidence of nonstationary behavior is apparent over the Gunnison and San Juan River basins.

  2. Water resources of the Big Black River basin, Mississippi

    USGS Publications Warehouse

    Wasson, B.E.

    1971-01-01

    Abundant supplies of water of good quality are available in the Big Black River basin from either ground-water or surface-water sources. For 90 percent of the time flow in the lower part of the Big Black River below Pickens is not less than 85 cfs (cubic feet per second), and low flows of more than 5 cfs are available in five of the eastern tributary streams in the upper half of the basin. Chemical quality of water in the streams is excellent, except for impairment caused by pollution at several places. The Big Black River basin is underlain by several thousand feet of clay, silt, sand, gravel, and limestone. This sedimentary material is mostly loose to semiconsolidated and is stratified. The beds dip to the southwest at the rate of 20 to 50 feet per mile. The Big Black River flows southwestward but at a lower gradient; therefore, any specific formation is at a greater depth below the river the farther one goes down stream. The formations crop out in northwest-southeast trending belts. Most of the available ground water is contained in six geologic units; thickness of these individual units ranges from 100 to 1,000 feet. The aquifers overlap to the extent that a well drilled to the base of fresh water will, in most places, penetrate two or more aquifers. Well depths range from less than 10 to 2,400 feet. Water suitable for most needs can be obtained from the aquifers available at most localities. Dissolved-solids content of water within an aquifer increases down the dip. Also, generally the deeper a well is the higher will be the dissolved-solids content of the water. Shallow ground water (less than 200 ft deep) in the basin usually contains about 100 mg/l (milligrams per liter) of dissolved solids. Most water in the basin from more than 2,500 feet below land surface contains m ore than 1,000 mg/l of dissolved solids. In several areas fresh water is deeper than 2,500 feet, but near the mouth of the Big Black River brackish water is only about 300 feet below land

  3. Intelligence-based automatic detection and classification of ground collapses using object-based image analysis method: a case study in Paitan of Pearl River delta

    NASA Astrophysics Data System (ADS)

    Dou, Jie; Zheng, Xiao-zhan; Qian, Jun-ping; Liu, Rui-hua; Wu, Qi-tao

    2009-10-01

    In this paper, a new method is proposed by applying case-based reasoning technique for detecting the ground collapses. The study demonstrates that the high resolution remote sensing images are suitable for monitoring the ground collapses in the study area with karst relief. With the help of object-based image analysis method, the generic algorithm (GA) for optimizing the spatial, shape, spectral, hierarchy and textural features was used in the multi-scale image segmentation with the good fitness value, and then the case library was built for detecting the collapse. The case library is reusable for place-independent detection. The proposed method has been tested in the Pearl River Delta in south China. The result of ground-collapse detection is well.

  4. Tissue distribution of organochlorine pesticides in fish collected from the Pearl River Delta, China: implications for fishery input source and bioaccumulation.

    PubMed

    Guo, Ying; Meng, Xiang-Zhou; Tang, Hong-Lei; Zeng, Eddy Y

    2008-09-01

    Fish tissues from different fishery types (freshwater farmed, seawater farmed and seawater wild) were analyzed for organochlorine pesticides (OCPs), with the aim to further our understanding of bioaccumulation, and reflect the state of different fishery environments. Significantly higher SigmaOCP levels were found in seawater farmed fish than others, and among three freshwater farmed species, the lowest levels occurred in filter-feeding fish (bighead carp). Liver contained the highest SigmaOCP levels, while no significant differences were found among other tissues. Among DDT components, p,p'-DDT was abundant in seawater fish, while for freshwater fish, p,p'-DDE was the predominant congeners, except for northern snakehead (34% for p,p'-DDE and 30% for p,p'-DDT). The new source of DDTs to freshwater fish ponds was partly attributed to dicofol, whereas sewage discharged from the Pearl River Delta and anti-fouling paint were likely the DDTs sources to seawater farmed fish. PMID:18063460

  5. Effects of landscape heterogeneity on the elevated trace metal concentrations in agricultural soils at multiple scales in the Pearl River Delta, South China.

    PubMed

    Li, Cheng; Li, Fangbai; Wu, Zhifeng; Cheng, Jiong

    2015-11-01

    Based on multiple geo-accumulation indices and correlation and partial redundancy analyses, we examined the spatial patterns of agricultural soil contaminations for As, Pb, Cd, Cr, and Ni in the Pearl River Delta, South China and their relations with landscape heterogeneity at small, medium and large spatial scales. We found that the concentrations of trace elements were slightly elevated, and most trace metals had a geogenic origin. Landscape variables explained 21-53% of the variation of elevated trace metal concentrations with an increasing explanatory power from the small to the large scale. The three variable groups representing parent materials, distance density characteristics and land use had different contributions to the elevated trace metals among scales. Both the distance density variables and land use pattern had a stronger influences on trace metal concentrations at a small scale than at a larger scale, while the parent materials was important at all the scales. PMID:26196316

  6. 76 FR 53531 - Rescinding the Notice of Intent for an Environmental Impact Statement (EIS): Hancock and Pearl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ...): Hancock and Pearl River Counties, MS AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Rescind... Interstate 10 south of Kiln and Interstate 59 in the City of Picayune, Hancock and Pearl River...

  7. Human impacts on river ice regime in the Carpathian Basin

    NASA Astrophysics Data System (ADS)

    Takács, Katalin; Nagy, Balázs; Kern, Zoltán

    2014-05-01

    examples from the Carpathian Basin represent some of the most common human impacts (engineering regulation, hydropower usage, water pollution), disturbing natural river ice regimes of mid-latitude rivers with densely populated or dynamically growing urban areas along their courses. In addition simple tests are also introduced to detect not only the climatic, but also the effect of anthropogenic impacts on river ice regime. As a result of river regulation on River Danube at Budapest a vanishing trend in river ice phenomena could be detected in the Danube records. The average ice-affected season shortened from 40 to 27 days, the average ice-covered season reduced greatly, from 27 to 7 days. In historical times the ice jams on the River Danube caused many times ice floods. The relative frequency of the break-up jam also decreased; moreover no ice flood occurred over the past 50 years. The changes due to hydropower usage are different upstream and downstream to the damming along the river. On Raba River upstream of the Nick dam at Ragyogóhíd, the ice-affected and ice-covered seasons were lengthened by 4 and 9 days, in contrast, downstream of the dam,