Mapping Water Vulnerability of the Yangtze River Basin: 1994-2013.

PubMed

Sun, Fengyun; Kuang, Wenhui; Xiang, Weining; Che, Yue

2016-11-01

A holistic understanding of the magnitude and long-term trend of water vulnerability is essential for making management decisions in a given river basin. Existing procedures to assess the spatiotemporal dynamic of water vulnerability in complex mega-scale river basins are inadequate; a new method named ensemble hydrologic assessment was proposed in this study, which allows collection of data and knowledge about many aspects of water resources to be synthesized in a useful way for vulnerability assessment. The objective of this study is to illustrate the practical utility of such an integrated approach in examining water vulnerability in the Yangtze River Basin. Overall, the results demonstrated that the ensemble hydrologic assessment model could largely explain the spatiotemporal evolution of water vulnerability. This paper improves understanding of the status and trends of water resources in the Yangtze River Basin.

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Modeling the impact of river discharge and wind on the hypoxia off Yangtze Estuary

NASA Astrophysics Data System (ADS)

Zheng, Jingjing; Gao, Shan; Liu, Guimei; Wang, Hui; Zhu, Xueming

2016-12-01

The phenomenon of low dissolved oxygen (known as hypoxia) in a coastal ocean system is closely related to a combination of anthropogenic and natural factors. Marine hypoxia occurs in the Yangtze Estuary, China, with high frequency and long persistence. It is related primarily to organic and nutrient enrichment influenced by river discharges and physical factors, such as water mixing. In this paper, a three-dimensional hydrodynamic model was coupled to a biological model to simulate and analyze the ecological system of the East China Sea. By comparing with the observation data, the model results can reasonably capture the physical and biochemical dynamics of the Yangtze Estuary. In addition, the sensitive experiments were also used to examine the role of physical forcing (river discharge, wind speed, wind direction) in controlling hypoxia in waters adjacent to the Yangtze Estuary. The results showed that the wind field and river discharge have significant impact on the hypoxia off the Yangtze Estuary. The seasonal cycle of hypoxia was relatively insensitive to synoptic variability in the river discharge, but integrated hypoxic areas were sensitive to the whole magnitude of river discharge. Increasing the river discharge was shown to increase hypoxic areas, while decreasing the river discharge tended to decrease hypoxic areas. The variations of wind speed and direction had a great impact on the integrated hypoxic areas.

Genetic structure and diversity of Nodularia douglasiae (Bivalvia: Unionida) from the middle and lower Yangtze River drainage.

PubMed

Liu, Xiongjun; Cao, Yanling; Xue, Taotao; Wu, Ruiwen; Zhou, Yu; Zhou, Chunhua; Zanatta, David T; Ouyang, Shan; Wu, Xiaoping

2017-01-01

The Yangtze River drainage in China is among the most species rich rivers for freshwater mussels (order Unionida) on Earth with at least 68 species known. The freshwater mussels of the Yangtze River face a variety of threats with indications that species are declining in abundance and area of occupancy. This study represents the first analyses of the genetic structure and diversity for the common and widespread freshwater mussel Nodularia douglasiae based on microsatellite DNA genotypes and mitochondrial DNA sequences. Phylogenetic analysis a fragment of the COI mitochondrial gene indicated that N. douglasiae collected from across the middle and lower Yangtze River drainage are monophyletic with N. douglasiae from Japan, Russia, and South Korea. The results of the analysis of both the mtDNA and microsatellite datasets indicated that the seven collection locations of N. douglasiae in the middle and lower Yangtze River drainage showed high genetic diversity, significant genetic differentiation and genetic structure, and stable population dynamics over time. Moreover, we found that the connections among tributaries rivers and lakes in the Yangtze River drainage were important in maintaining gene flow among locations that N. douglasiae inhabits. An understanding of the genetic structure and diversity of a widespread species like N. douglasiae could be used as a surrogate to better understand the populations of other freshwater mussel species that are more rare in the Yangtze River drainage. At the same time, these results could provide a basis for the protection of genetic diversity and management of unionid mussels diversity and other aquatic organisms in the system.

Genetic structure and diversity of Nodularia douglasiae (Bivalvia: Unionida) from the middle and lower Yangtze River drainage

PubMed Central

Liu, Xiongjun; Cao, Yanling; Xue, Taotao; Wu, Ruiwen; Zhou, Yu; Zhou, Chunhua; Zanatta, David T.; Ouyang, Shan

2017-01-01

The Yangtze River drainage in China is among the most species rich rivers for freshwater mussels (order Unionida) on Earth with at least 68 species known. The freshwater mussels of the Yangtze River face a variety of threats with indications that species are declining in abundance and area of occupancy. This study represents the first analyses of the genetic structure and diversity for the common and widespread freshwater mussel Nodularia douglasiae based on microsatellite DNA genotypes and mitochondrial DNA sequences. Phylogenetic analysis a fragment of the COI mitochondrial gene indicated that N. douglasiae collected from across the middle and lower Yangtze River drainage are monophyletic with N. douglasiae from Japan, Russia, and South Korea. The results of the analysis of both the mtDNA and microsatellite datasets indicated that the seven collection locations of N. douglasiae in the middle and lower Yangtze River drainage showed high genetic diversity, significant genetic differentiation and genetic structure, and stable population dynamics over time. Moreover, we found that the connections among tributaries rivers and lakes in the Yangtze River drainage were important in maintaining gene flow among locations that N. douglasiae inhabits. An understanding of the genetic structure and diversity of a widespread species like N. douglasiae could be used as a surrogate to better understand the populations of other freshwater mussel species that are more rare in the Yangtze River drainage. At the same time, these results could provide a basis for the protection of genetic diversity and management of unionid mussels diversity and other aquatic organisms in the system. PMID:29261733

Effects of fish community on occurrences of Yangtze finless porpoise in confluence of the Yangtze and Wanhe Rivers.

PubMed

Zhang, Xiaoke; Yu, Daoping; Wang, Huili; Wan, An; Chen, Minmin; Tao, Feng; Song, Zunrong

2015-06-01

The Yangtze finless porpoise is a subspecies of narrow-ridged finless porpoise endemic to the middle and lower reaches of the Yangtze River and the adjoining Poyang and Dongting Lakes. With the depletion of fish stocks in the Yangtze River in recent decades, food availability has become the most important factor affecting the survival of this subspecies. Despite this, the relationships between fish community and occurrences of porpoise are far from being fully understood. Therefore, during September 2013 to August 2014, the occurrences of porpoise were investigated in confluence of the Yangtze and Wanhe Rivers; fish community was also surveyed synchronously in confluence and two adjacent transects. The results showed that (1) the confluence had maximum fish species richness, and the main dominant species was upper fish, while the other two transects were mainly dominated by demersal fish. ANOVA analyses showed that individual number and yield of upper fish which can be eaten by porpoise (upper edible fish) in the confluence were significantly higher than other two transects. (2) Average group size of the porpoise was 3.7 ± 1.8 individuals. The occurrences of porpoise in different seasons had great differences, and the porpoise was more likely to be detected in autumn and winter. (3) Fish community had significant effects on occurrences of porpoise, and the main influencing factors were fish species richness, individual number, and yield of edible fish, especially the upper edible fish. The results of this study will have important implications for the conservation of porpoise.

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

USGS Publications Warehouse

Chapman, Duane C.

2006-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2007-03-01

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

Assessing natural and anthropogenic influences on water discharge and sediment load in the Yangtze River, China.

PubMed

Zhao, Yifei; Zou, Xinqing; Liu, Qing; Yao, Yulong; Li, Yali; Wu, Xiaowei; Wang, Chenglong; Yu, Wenwen; Wang, Teng

2017-12-31

The water discharge and sediment load of rivers are changing substantially under the impacts of climate change and human activities, becoming a hot issue in hydro-environmental research. In this study, the water discharge and sediment load in the mainstream and seven tributaries of the Yangtze River were investigated by using long-term hydro-meteorological data from 1953 to 2013. The non-parametric Mann-Kendall test and double mass curve (DMC) were used to detect trends and abrupt change-points in water discharge and sediment load and to quantify the effects of climate change and human activities on water discharge and sediment load. The results are as follows: (1) the water discharge showed a non-significant decreasing trend at most stations except Hukou station. Among these, water discharge at Dongting Lake and the Min River basin shows a significant decreasing trend with average rates of -13.93×10 8 m 3 /year and -1.8×10 8 m 3 /year (P<0.05), respectively. However, the sediment load exhibited a significant decreasing trend in all tributaries of the Yangtze River. (2) No significant abrupt change-points were detected in the time series of water discharge for all hydrological stations. In contrast, significant abrupt change-points were detected in sediment load, most of these changes appeared in the late 1980s. (3) The water discharge was mainly influenced by precipitation in the Yangtze River basin, whereas sediment load was mainly affected by climate change and human activities; the relative contribution ratios of human activities were above 70% for the Yangtze River. (4) The decrease of sediment load has directly impacted the lower Yangtze River and the delta region. These results will provide a reference for better resource management in the Yangtze River Basin. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Yangtze River source water on genomic polymorphisms of male mice detected by RAPD.

PubMed

Zhang, Xiaolin; Zhang, Zongyao; Zhang, Xuxiang; Wu, Bing; Zhang, Yan; Yang, Liuyan; Cheng, Shupei

2010-02-01

In order to evaluate the environmental health risk of drinking water from Yangtze River source, randomly amplified polymorphic DNA (RAPD) markers were used to detect the effects of the source water on genomic polymorphisms of hepatic cell of male mice (Mus musculus, ICR). After the mice were fed with source water for 90 days, RAPD-polymerase chain reactions (PCRs) were performed on hepatic genomic DNA using 20 arbitrary primers. Totally, 189 loci were generated, including 151 polymorphic loci. On average, one PCR primer produced 5.3, 4.9 and 4.8 bands for each mouse in the control, the groups fed with source water and BaP solution, respectively. Compared with the control, feeding mice with Yangtze River source water caused 33 new loci to appear and 19 to disappear. Statistical analysis of RAPD printfingers revealed that Yangtze River source water exerted a significant influence on the hepatic genomic polymorphisms of male mice. This study suggests that RAPD is a reliable and sensitive method for the environmental health risk of Yangtze River source water.

[Spatio-temporal variations of origin, distribution and diffusion of Oncomelania hupensis in Yangtze River Basin].

PubMed

Deng, Chen; Li-Yong, Wen

2017-10-24

As the only intermediate host of Schistosoma japonicum, Oncomelania hupensis in China is mainly distributed in the Yangtze River Basin. The origin of the O. hupensis and the spatio-temporal variations of its distribution and diffusion in the Yangtze River Basin and the influencing factors, as well as significances in schistosomiasis elimination in China are reviewed in this paper.

An investigation of enhanced recessions in Poyang Lake: Comparison of Yangtze River and local catchment impacts

NASA Astrophysics Data System (ADS)

Zhang, Qi; Ye, Xu-chun; Werner, Adrian D.; Li, Yun-liang; Yao, Jing; Li, Xiang-hu; Xu, Chong-yu

2014-09-01

Changes in lake hydrological regimes and the associated impacts on water supplies and ecosystems are internationally recognized issues. During the past decade, the persistent dryness of Poyang Lake (the largest freshwater lake in China) has caused water supply and irrigation crises for the 12.4 million inhabitants of the region. There is conjecture as to whether this dryness is caused by climate variability and/or human activities. This study examines long-term datasets of catchment inflow and Lake outflow, and employs a physically-based hydrodynamic model to explore catchment and Yangtze River controls on the Lake's hydrology. Lake water levels fell to their lowest during 2001-2010 relative to previous decades. The average Lake size and volume reduced by 154 km2 and 11 × 108 m3 during the same period, compared to those for the preceding period (1970-2000). Model simulations demonstrated that the drainage effect of the Yangtze River was the primary causal factor. Modeling also revealed that, compared to climate variability impacts on the Lake catchment, modifications to Yangtze River flows from the Three Gorges Dam have had a much greater impact on the seasonal (September-October) dryness of the Lake. Yangtze River effects are attenuated in the Lake with distance from the River, but nonetheless propagate some 100 km to the Lake's upstream limit. Proposals to build additional dams in the upper Yangtze River and its tributaries are expected to impose significant challenges for the management of Poyang Lake. Hydraulic engineering to modify the flow regime between the Lake and the Yangtze River would somewhat resolve the seasonal dryness of the Lake, but will likely introduce other issues in terms of water quality and aquatic ecosystem health, requiring considerable further research.

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

PubMed

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

2017-01-05

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

Impacts of large dams on the complexity of suspended sediment dynamics in the Yangtze River

NASA Astrophysics Data System (ADS)

Wang, Yuankun; Rhoads, Bruce L.; Wang, Dong; Wu, Jichun; Zhang, Xiao

2018-03-01

The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1-30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics "signal" becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River.

Genomic evidence for the population genetic differentiation of Misgurnus anguillicaudatus in the Yangtze River basin of China.

PubMed

Yi, Shaokui; Wang, Weimin; Zhou, Xiaoyun

2018-02-21

Misgurnus anguillicaudatus, an important aquatic species, is mainly distributed in the Yangtze River basin. To reveal the population genetic structure of M. anguillicaudatus distributed in the Yangtze River basin, genotyping by sequencing (GBS) technique was employed to detect the genome wide genetic variations of M. anguillicaudatus. A total of 30.03 Gb raw data were yielded from 70 samples collected from 15 geographic sites located in the Yangtze River basin. Subsequently, 2092 high quality SNPs were genotyped across these samples and used for a series of genetic analysis. The results of genetic analysis showed that high levels of genetic diversity were observed and the populations from upper reaches (UR) were significantly differentiated from the middle and lower reaches (MLR) of Yangtze River basin. Meanwhile, no significant isolation by distance was detected among the populations. Ecological factors (e.g. complicated topography and climatic environment) and anthropogenic factors (e.g. aquaculture and agriculture cultivation) might account for the genetic disconnectivity between UR and MLR populations. This study provided valuable genetic data for the future breeding program and also for the conversation and scientific utilization of those abundant genetic resources stored in the Yangtze River basin. Copyright © 2018 Elsevier Inc. All rights reserved.

Forecasting the Amount of Waste-Sewage Water Discharged into the Yangtze River Basin Based on the Optimal Fractional Order Grey Model.

PubMed

Li, Shuliang; Meng, Wei; Xie, Yufeng

2017-12-23

With the rapid development of the Yangtze River economic belt, the amount of waste-sewage water discharged into the Yangtze River basin increases sharply year by year, which has impeded the sustainable development of the Yangtze River basin. The water security along the Yangtze River basin is very important for China, It is something aboutwater security of roughly one-third of China's population and the sustainable development of the 19 provinces, municipalities and autonomous regions among the Yangtze River basin. Therefore, a scientific prediction of the amount of waste-sewage water discharged into Yangtze River basin has a positive significance on sustainable development of industry belt along with Yangtze River basin. This paper builds the fractional DWSGM(1,1)(DWSGM(1,1) model is short for Discharge amount of Waste Sewage Grey Model for one order equation and one variable) model based on the fractional accumulating generation operator and fractional reducing operator, and calculates the optimal order of "r" by using particle swarm optimization(PSO)algorithm for solving the minimum average relative simulation error. Meanwhile, the simulation performance of DWSGM(1,1)model with the optimal fractional order is tested by comparing the simulation results of grey prediction models with different orders. Finally, the optimal fractional order DWSGM(1,1)grey model is applied to predict the amount of waste-sewage water discharged into the Yangtze River basin, and corresponding countermeasures and suggestions are put forward through analyzing and comparing the prediction results. This paper has positive significance on enriching the fractional order modeling method of the grey system.

Forecasting the Amount of Waste-Sewage Water Discharged into the Yangtze River Basin Based on the Optimal Fractional Order Grey Model

PubMed Central

Li, Shuliang; Meng, Wei; Xie, Yufeng

2017-01-01

With the rapid development of the Yangtze River economic belt, the amount of waste-sewage water discharged into the Yangtze River basin increases sharply year by year, which has impeded the sustainable development of the Yangtze River basin. The water security along the Yangtze River basin is very important for China, It is something about water security of roughly one-third of China’s population and the sustainable development of the 19 provinces, municipalities and autonomous regions among the Yangtze River basin. Therefore, a scientific prediction of the amount of waste-sewage water discharged into Yangtze River basin has a positive significance on sustainable development of industry belt along with Yangtze River basin. This paper builds the fractional DWSGM (1,1) (DWSGM (1,1) model is short for Discharge amount of Waste Sewage Grey Model for one order equation and one variable) model based on the fractional accumulating generation operator and fractional reducing operator, and calculates the optimal order of “r” by using particle swarm optimization (PSO) algorithm for solving the minimum average relative simulation error. Meanwhile, the simulation performance of DWSGM (1,1) model with the optimal fractional order is tested by comparing the simulation results of grey prediction models with different orders. Finally, the optimal fractional order DWSGM (1,1) grey model is applied to predict the amount of waste-sewage water discharged into the Yangtze River basin, and corresponding countermeasures and suggestions are put forward through analyzing and comparing the prediction results. This paper has positive significance on enriching the fractional order modeling method of the grey system. PMID:29295517

Water mass interaction in the confluence zone of the Daning River and the Yangtze River--a driving force for algal growth in the Three Gorges Reservoir.

PubMed

Holbach, Andreas; Wang, Lijing; Chen, Hao; Hu, Wei; Schleicher, Nina; Zheng, Binghui; Norra, Stefan

2013-10-01

Increasing eutrophication and algal bloom events in the Yangtze River Three Gorges Reservoir, China, are widely discussed with regard to changed hydrodynamics and nutrient transport and distribution processes. Insights into water exchange and interaction processes between water masses related to large-scale water level fluctuations in the reservoir are crucial to understand water quality and eutrophication dynamics. Therefore, confluence zones of tributaries with the Yangtze River main stream are dedicated key interfaces. In this study, water quality data were recorded in situ and on-line in varying depths with the MINIBAT towed underwater multi-sensor system in the confluence zone of the Daning River and the Yangtze River close to Wushan City during 1 week in August 2011. Geostatistical evaluation of the water quality data was performed, and results were compared to phosphorus contents of selective water samples. The strongly rising water level throughout the measurement period caused Yangtze River water masses to flow upstream into the tributary and supply their higher nutrient and particulate loads into the tributary water body. Rapid algal growth and sedimentation occurred immediately when hydrodynamic conditions in the confluence zone became more serene again. Consequently, water from the Yangtze River main stream can play a key role in providing nutrients to the algal bloom stricken water bodies of its tributaries.

Outbreaks of the Brown Planthopper Nilaparvata lugens (Stål) in the Yangtze River Delta: Immigration or Local Reproduction?

PubMed Central

Zhai, Bao-Ping; Lu, Ming-Hong; Liu, Wan-Cai; Zhu, Feng; Wu, Xiang-Wen; Chen, Gui-Hua; Zhang, Xiao-Xi

2014-01-01

An effective control strategy for migratory pests is difficult to implement because the cause of infestation (i.e., immigration or local reproduction) is often not established. In particular, the outbreak mechanisms of the brown planthopper, Nilaparvata lugens (Stål), an insect causing massive losses in rice fields in the Yangtze River Delta in China, are frequently unclear. Field surveys of N. lugens were performed in Jiangsu and Zhejiang Provinces in 2008 to 2010 and related historical data from 2003 onwards were collected and analyzed to clarify the cause of these infestations. Results showed that outbreaks of N. lugens in the Yangtze River Delta were mostly associated with an extremely high increase in population. Thus, reproduction rather than immigration from distant sources were the cause of the infestations. Although mass migration occurred late in the season (late August and early September), the source areas of N. lugens catches in the Yangtze River Delta were mainly located in nearby areas, including the Yangtze River Delta itself, Anhui and northern Jiangxi Provinces. These regions collectively form the lower-middle reaches of the Yangtze River, and the late migration can thus be considered as an internal bioflow within one population. PMID:24558459

Outbreaks of the brown planthopper Nilaparvata lugens (Stål) in the Yangtze River Delta: immigration or local reproduction?

PubMed

Hu, Gao; Lu, Fang; Zhai, Bao-Ping; Lu, Ming-Hong; Liu, Wan-Cai; Zhu, Feng; Wu, Xiang-Wen; Chen, Gui-Hua; Zhang, Xiao-Xi

2014-01-01

An effective control strategy for migratory pests is difficult to implement because the cause of infestation (i.e., immigration or local reproduction) is often not established. In particular, the outbreak mechanisms of the brown planthopper, Nilaparvata lugens (Stål), an insect causing massive losses in rice fields in the Yangtze River Delta in China, are frequently unclear. Field surveys of N. lugens were performed in Jiangsu and Zhejiang Provinces in 2008 to 2010 and related historical data from 2003 onwards were collected and analyzed to clarify the cause of these infestations. Results showed that outbreaks of N. lugens in the Yangtze River Delta were mostly associated with an extremely high increase in population. Thus, reproduction rather than immigration from distant sources were the cause of the infestations. Although mass migration occurred late in the season (late August and early September), the source areas of N. lugens catches in the Yangtze River Delta were mainly located in nearby areas, including the Yangtze River Delta itself, Anhui and northern Jiangxi Provinces. These regions collectively form the lower-middle reaches of the Yangtze River, and the late migration can thus be considered as an internal bioflow within one population.

[Shifting path of industrial pollution gravity centers and its driving mechanism in Pan-Yangtze River Delta].

PubMed

Zhao, Hai-Xia; Jiang, Xiao-Wei; Cui, Jian-Xin

2014-11-01

Shifting path of industrial pollution gravity centers is the response of environmental special formation during the industry transfer process, in order to prove the responding of industrial pollution gravity centers to industry transfer in economically developed areas, this paper calculates the gravity centers of industrial wastewater, gas and solid patterns and reveals the shifting path and its driving mechanism, using the data of industrial pollution in the Pan-Yangtze River Delta from 2000 to 2010. The results show that the gravity center of the industrial waste in Pan-Yangtze River Delta shifts for sure in the last 10 years, and gravity center of solid waste shifts the maximum distance within the three wastes, which was 180.18 km, and shifting distances for waste gas and waste water were 109.51 km and 85.92 km respectively. Moreover, the gravity center of the industrial waste in Pan-Yangtze River Delta shifts westwards, and gravity centers of waste water, gas and solid shift for 0.40 degrees, 0.17 degrees and 0.03 degrees respectively. The shifting of industrial pollution gravity centers is driven by many factors. The rapid development of the heavy industry in Anhui and Jiangxi provinces results in the westward shifting of the pollutions. The optimization and adjustment of industrial structures in Yangtze River Delta region benefit to alleviating industrial pollution, and high-polluting industries shifted to Anhui and Jiangxi provinces promotes pollution gravity center shifting to west. While the development of massive clean enterprise, strong environmental management efforts and better environmental monitoring system slow the shifting trend of industrial pollution to the east in Yangtze River Delta. The study of industrial pollution gravity shift and its driving mechanism provides a new angle of view to analyze the relationship between economic development and environmental pollution, and also provides academic basis for synthetical management and control of

27 CFR 9.78 - Ohio River Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ohio River Valley. 9.78... River Valley. (a) Name. The name of the viticultural area described in this section is “Ohio River Valley.” (b) Approved maps. The approved maps for determining the boundary of the Ohio River Valley...

Variation in MERRA-2 aerosol optical depth over the Yangtze River Delta from 1980 to 2016

NASA Astrophysics Data System (ADS)

Sun, Enwei; Che, Huizheng; Xu, Xiaofeng; Wang, Zhenzhu; Lu, Chunsong; Gui, Ke; Zhao, Hujia; Zheng, Yu; Wang, Yaqiang; Wang, Hong; Sun, Tianze; Liang, Yuanxin; Li, Xiaopan; Sheng, Zhizhong; An, Linchang; Zhang, Xiaoye; Shi, Guangyu

2018-05-01

In this study, 765 instantaneous MERRA-2 (second Modern-Era Retrospective analysis for Research and Applications) aerosol optical depth (AOD) values at 550 nm were compared with those of a sky radiometer in Hefei (31.90° N, 117.17° E) for the different seasons from March 2007 to February 2010. The correlation coefficients (R) were 0.88, 0.83, 0.88, and 0.80 in spring, summer, autumn, and winter, respectively. The MERRA-2 AOD is also compared with MODIS Aqua AOD in the entire Yangtze River Delta, and good agreement has been obtained. The MERRA-2 AOD product was used to analyze the spatial distribution and temporal variation of the annual, seasonal and monthly means of the AOD over the Yangtze River Delta region from 1980 to 2016 (37 years). The mean values of the MERRA-2 AOD during the study period show that the AOD (between 0.45 and 0.55) in the northern area of the Yangtze River Delta was higher than that (between 0.30 and 0.45) of the southern area. The northwest part of the Yangtze River Delta had the highest mean AOD values (between 0.50 and 0.55). The AOD increased slowly in the 1980s and 1990s, followed by a rapid increase between 2001 and 2010. An AOD decrease can be seen from 2011 to 2016. The mean AOD in each month is discussed. High AOD was observed in March, April, and June, while low AOD could be seen in September, October, November, and December. Three different area types (large cities, medium-sized cities, and remote areas) had nearly the same annual AOD variation. Large cities had the highest AOD (about 0.48), while remote areas had the lowest (about 0.42). In summer, the AOD in remote areas was much lower than that in cities. The AOD variational trend over the Yangtze River Delta was studied during two periods. The increasing trend could be seen over the entire Yangtze River Delta in each month from 1980 to 2009. A decreasing trend was found all over the Yangtze River Delta in January, February, March, July, October, and November, whereas in

Climate Drivers of Spatiotemporal Variability of Precipitation in the Source Region of Yangtze River

NASA Astrophysics Data System (ADS)

Du, Y.; Berndtsson, R.; An, D.; Yuan, F.

2017-12-01

Variability of precipitation regime has significant influence on the environment sustainability in the source region of Yangtze River, especially when the vegetation degradation and biodiversity reduction have already occurred. Understanding the linkage between variability of local precipitation and global teleconnection patterns is essential for water resources management. Based on physical reasoning, indices of the climate drivers can provide a practical way of predicting precipitation. Due to high seasonal variability of precipitation, climate drivers of the seasonal precipitation also varies. However, few reports have gone through the teleconnections between large scale patterns with seasonal precipitation in the source region of Yangtze River. The objectives of this study are therefore (1) assessment of temporal trend and spatial variability of precipitation in the source region of Yangtze River; (2) identification of climate indices with strong influence on seasonal precipitation anomalies; (3) prediction of seasonal precipitation based on revealed climate indices. Principal component analysis and Spearman rank correlation were used to detect significant relationships. A feed-forward artificial neural network(ANN) was developed to predict seasonal precipitation using significant correlated climate indices. Different influencing climate indices were revealed for precipitation in each season, with significant level and lag times. Significant influencing factors were selected to be the predictors for ANN model. With correlation coefficients between observed and simulated precipitation over 0.5, the results were eligible to predict the precipitation of spring, summer and winter using teleconnections, which can improve integrated water resources management in the source region of Yangtze River.

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

PubMed

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

2014-10-21

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

Scanning vertical distributions of typical aerosols along the Yangtze River using elastic lidar.

PubMed

Fan, Shidong; Liu, Cheng; Xie, Zhouqing; Dong, Yunsheng; Hu, Qihou; Fan, Guangqiang; Chen, Zhengyi; Zhang, Tianshu; Duan, Jingbo; Zhang, Pengfei; Liu, Jianguo

2018-07-01

In recent years, China has experienced heavy air pollution, especially haze caused by particulate matter (PM). The compositions, horizontal distributions, transport, and chemical formation mechanisms of PM and its precursors have been widely investigated in China based on near-ground measurements. However, the understanding of the distributions and physical and chemical processes of PM in the vertical direction remains limited. In this study, an elastic lidar was employed to investigate the vertical profiles of aerosols along the Yangtze River during the Yangtze River Campaign of winter 2015. Some typical aerosols were identified and some events were analyzed in three cases. Dust aerosols can be transported from the Gobi Desert to the Yangtze River basin across a long distance at both low and high altitudes in early December. The transport route was perpendicular to the ship track, suggesting that the dust aerosols may have affected a large area. Moreover, during transport, some dust was also affected by the areas below its transport route since some anthropogenic pollutants were mixed with the dust and changed some of its optical properties. Biomass-burning aerosols covering a distant range along the Yangtze River were identified. This result directly shows the impact areas of biomass-burning aerosols in some agricultural fields. Some directly emitted aerosol plumes were observed, and direct effects of such plumes were limited both temporally and spatially. In addition, an aerosol plume with very low linear depolarization ratios, probably formed through secondary processes, was also observed. These results can help us better understand aerosols in large spatial scales in China and can be useful to regional haze studies. Copyright © 2018. Published by Elsevier B.V.

Bioanalytical and instrumental analysis of estrogenic activities in drinking water sources from Yangtze River Delta.

PubMed

Hu, Xinxin; Shi, Wei; Cao, Fu; Hu, Guanjiu; Hao, Yingqun; Wei, Si; Wang, Xinru; Yu, Hongxia

2013-02-01

The estrogenic activities of source water from Yangtze River, Huaihe River, Taihu Lake and groundwater in Yangtze River Delta in the dry and wet season were determined by use of reporter gene assays based on African green monkey kidney (CV-1) cell lines. Higher estrogenic activities were observed in the dry season, and the estrogenic potentials in water samples from Taihu Lake were greater than other river basins. None of the samples from groundwater showed estrogen receptor (ER) agonist activity. The 17β-Estradiol (E2) equivalents (EEQs) of water samples in the dry season ranged from 9.41×10(-1) to 1.20×10(1) ng E2 L(-1). In the wet season, EEQs of all the water samples were below the detection limit as 9.00×10(-1) ng E2 L(-1) except for one sample from Huaihe River. The highest contribution of E2 was detected in Yangtze River as 99% of estrogenic activity. Nonylphenol (NP, 100% detection rate) and octylphenol (OP, 100% detection rate) might also be responsible for the estrogenic activities in water sources. Potential health risk induced by the estrogenic chemicals in source water may be posed to the residents through water drinking. Copyright © 2012 Elsevier Ltd. All rights reserved.

Spatio-temporal distribution and sources of Pb identified by stable isotopic ratios in sediments from the Yangtze River Estuary and adjacent areas.

PubMed

Chen, Bin; Liu, Jian; Hu, Limin; Liu, Ming; Wang, Liang; Zhang, Xilin; Fan, Dejiang

2017-02-15

To understand the spatio-temporal distribution and sources of Pb in the sediments of the Yangtze River Estuary and its adjacent areas, 25 surface sediments and 1 sediment core were collected from the study areas. The concentrations of Al and Pb of these sediments exhibit a decreasing trend from the nearshore towards the offshore, with higher concentrations in the coastal areas of the East China Sea (ECS) and southwest of Jeju Island. According to the stable isotopic ratios of Pb, in combination with the elemental ratios and clay mineral data, it is inferred that sedimentary Pb in the surface sediments of the coastal areas of the ECS may come primarily from the Yangtze River, while the Pb southwest of Jeju Island is probably derived from both the Yangtze and Yellow Rivers. The particulate Pb derived from the Yangtze River was possibly dispersed along two paths: the path southward along the coastline of the ECS and the path eastward associated with the Changjiang Diluted Water (CDW), which crosses the shelf of the ECS towards the area southeast of Jeju Island. Although the Yangtze River Basin witnessed rapid economic development during the period from the late 1970s to the middle 1990s, the influence of human activity on Pb concentration remained weak in the Yangtze River Estuary. Since the early 2000s, however, sedimentary Pb has been significantly increasing in the coastal mud areas of the ECS due to the increasing influence of human activity, such as the increase in atmospheric emission of anthropogenic Pb in China, construction of the Three Gorges Dam (TGD), and the construction of smaller dams in the upper reaches of the Yangtze River. Coal combustion and the smelting of non-ferrous metals are possible anthropogenic sources for the sedimentary Pb in the Yangtze River Estuary. Copyright © 2016. Published by Elsevier B.V.

Tidal impacts on the subtidal flow division at the main bifurcation in the Yangtze River Delta

NASA Astrophysics Data System (ADS)

Zhang, Wei; Feng, Haochuan; Hoitink, A. J. F.; Zhu, Yuliang; Gong, Fei; Zheng, Jinhai

2017-09-01

Flow division at bifurcations in the Yangtze Estuary has received ample attention, since it may control the pathways of terrestrial sediments over downstream river branches including the 12.5 m Deepwater Navigation channel. While some efforts have been made to interpret flow division at the bifurcations of the Yangtze Estuary, little attention has been paid to the role of tides. Flow division at estuarine bifurcations is made complicated by tides that propagate from the outlet of the tidal channels into the delta. To quantify the tidal influence on the distribution of river discharge, and more generally, to understand the mechanisms governing the subtidal flow division at the tidally affected bifurcation in the Yangtze River Delta, a two-dimensional hydrodynamic model is employed. In this model, the landward boundary is chosen beyond the tidal limit, where the tidal motion has faded out entirely. The seaward boundary is chosen such that the river discharge does not influence the water level. Subtidal discharges are decomposed using the method of factor separation, to distinguish between the effects of tides, river discharge and river-tide interactions on the subtidal flow division. Results indicate that tides modify the river discharge distribution over distributary channels in the Yangtze River Delta, particularly in the dry season. A significant difference in the subtidal flow division during spring tide and neap tide shows that the tidally averaged flow division over the distributaries in the delta greatly depends on tidal amplitude. By varying the river discharge at the landward boundary and amplitudes and phases of the principal tidal constituents at the seaward boundary of the established model, the sensitivities of the subtidal flow division to the river discharge and tidal amplitude variation were investigated in detail. Generally, the tidal impacts on the subtidal flow division are around 12% to 22%, with river discharge varying from 30,000 m3s-1 to 20

A comparative study of the flux and fate of the Mississippi and Yangtze river sediments

NASA Astrophysics Data System (ADS)

Xu, K.; Yang, S. L.

2015-03-01

Large rivers play a key role in delivering water and sediment into the global oceans. Large-river deltas and associated coastlines are important interfaces for material fluxes that have a global impact on marine processes. In this study, we compare water and sediment discharge from Mississippi and Yangtze rivers by assessing: (1) temporal variation under varying climatic and anthropogenic impacts, (2) delta response of the declining sediment discharge, and (3) deltaic lobe switching and Holocene sediment dispersal patterns on the adjacent continental shelves. Dam constructions have decreased both rivers' sediment discharge significantly, leading to shoreline retreat along the coast. The sediment dispersal of the river-dominated Mississippi Delta is localized but for the tide-dominated Yangtze Delta is more diffuse and influenced by longshore currents. Sediment declines and relative sea level rises have led to coastal erosion, endangering the coasts of both rivers.

Exhumation Reconstruction of the Xiangcheng Area, SE Tibetan Plateau. Implication on the Evolution of the Yangtze River in the Cenozoic.

NASA Astrophysics Data System (ADS)

Gourbet, L.; Yang, R.; Fellin, M. G.; Gong, J.; Maden, C.

2016-12-01

Geodynamic processes associated with timing of river incision and river network reorganization on the Tibetan plateau margins remain controversial. In particular, hydrographic network modifications in SE Tibet have been interpreted as related with regional-scale uplift or fault motion. The paleocourse of the upper Yangtze river (Jinsha Sha) and the timing of the establishment of its modern course are highly debated, leading to conflicting models of the plateau evolution. For example, estimated ages for the formation of the Yangtze first bend (where the river shifts from flowing southward to northward) range from the Eocene to the Pliocene. River incision can be reconstructed using low-temperature thermochronometry. However, the lack of suitable rocks along the main riverbed of the Yangtze makes it challenging. To address this problem, we perform a local study of the Xiangcheng area, located in Sichuan, about 150 km upstream of the first bend and drained by tributaries of the upper Yangtze. We combine a tectono-geomorphic analysis to a reconstruction of exhumation rates using (U-Th-Sm)/He thermochronometry. The study area is characterized by the NW-SE trending, active left-lateral Xiangcheng fault, which is attested by crustal-depth seismic activity. Importantly, the courses of two tributaries of the Yangtze are deflected along the Xiangcheng fault, suggesting that the fault partly controls the evolution of the upper Yangtze course. Locally, the fault also exhibits triangular facets, suggesting normal motion probably related to the fault segmentation. Granite samples from the Xiangcheng pluton were collected along three altitudinal profiles and analyzed using zircon and apatite (U-Th-Sm)/He thermochronometry. We will discuss the results and their implications on exhumation and on the Yangtze river history during the Cenozoic.

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

Richness and diversity of helminth communities in the Japanese grenadier anchovy, Coilia nasus, during its anadromous migration in the Yangtze River, China.

PubMed

Li, Wen X; Zou, Hong; Wu, Shan G; Song, Rui; Wang, Gui T

2012-06-01

To determine the relationship between the species richness, diversity of helminth communities, and migration distance during upward migration from coast to freshwater, helminth communities in the anadromous fish Coilia nasus were investigated along the coast of the East China Sea, the Yangtze Estuary, and 3 localities on the Yangtze River. Six helminth species were found in 224 C. nasus . Changes in salinity usually reduced the survival time of parasites, and thus the number of helminth species and their abundance. Except for the 2 dominant helminths, the acanthocephalan Acanthosentis cheni and the nematode Contracaecum sp., mean abundance of other 4 species of helminths was rather low (<1.0) during the upward migration in the Yangtze River. Mean abundance of the 2 dominant helminths peaked in the Yangtze Estuary and showed no obvious decrease among the 3 localities on the Yangtze River. Mean species richness, Brillouin's index, and Shannon index were also highest in the estuary (1.93 ± 0.88, 0.28 ± 0.25, and 0.37 ± 0.34, respectively) and did not exhibit marked decline at the 3 localities on the Yangtze River. A significant negative correlation was not seen between the similarity and the geographical distance (R  =  -0.5104, P  =  0.1317). The strong salinity tolerance of intestinal helminths, relatively brief stay in the Yangtze River, and large amount of feeding on small fish and shrimp when commencing spawning migration perhaps were responsible for the results.

Assessing dissolved inorganic nitrogen flux in the Yangtze River, China: Sources and scenarios

NASA Astrophysics Data System (ADS)

Xu, Hao; Chen, Zhongyuan; Finlayson, Brian; Webber, Michael; Wu, Xiaodan; Li, Maotian; Chen, Jing; Wei, Taoyuan; Barnett, Jon; Wang, Mark

2013-07-01

This study gives a thorough assessment of the occurrences of dissolved inorganic nitrogen (DIN) in the Yangtze River in the past half century. The results have shown that nitrogen fertilizer, a major DIN source, has been replaced by domestic sewage in the last decade, which has dramatically driven up DIN loads in the Yangtze. DIN concentrations showed a rapid increase from < 0.5 mg L- 1 in the 1960s to nearly 1.5 mg L- 1 at the end of the 1990s. Since then DIN has remained steady at ca. 1.6-1.8 mg L- 1. A significant relationship between the historical DIN record at the downstream gauging station (Datong) and nitrogen (N) sources in the Yangtze River basin is established using principal components analysis. This allows us to apportion DIN loads for the year 2007 (the most recent year of measured DIN data available) to various N sources, listed here in order of weight: sewage (0.391 million tons); atmosphere (0.358 million tons); manure (0.318 million tons), N-fertilizer (0.271 million tons). Therefore, we estimated that a DIN load of 1.339 × 106 t was delivered to the lower Yangtze and its estuarine water in that year. We established scenarios to predict DIN concentrations in the lower Yangtze at 10 year intervals to 2050. For a dry year (20,000 m3 s- 1) DIN concentrations would range from 2.2-3.0 mg L- 1 for 2020-2050. This far exceeds the 2.0 mg L- 1 defined on the Chinese National Scale as the worst class for potable source water. The scenario results suggest that upgrading the sewage treatment systems throughout the basin will be an effective way to help reduce DIN concentrations to less than 2.0 mg L- 1 in the lower Yangtze. This would save the Shanghai megacity from the increasing threat of heavily polluted water sources, where > 23 million people are at present dependent on the Yangtze estuary for 70% of their freshwater intake.

Temporal and Spatial Variation of Water Yield Modulus in the Yangtze River Basin in Recent 60 Years

NASA Astrophysics Data System (ADS)

Shi, Xiaoqing; Weng, Baisha; Qin, Tianling

2018-01-01

The Yangtze River Basin is the largest river basin of Asia and the third largest river basin of the world, the gross water resources amount ranks first in the river basins of the country, and it occupies an important position in the national water resources strategic layout. Under the influence of climate change and human activities, the water cycle has changed. The temporal and spatial distribution of precipitation in the basin is more uneven and the floods are frequent. In order to explore the water yield condition in the Yangtze River Basin, we selected the Water Yield Modulus (WYM) as the evaluation index, then analyzed the temporal and spatial evolution characteristics of the WYM in the Yangtze River Basin by using the climate tendency method and the M-K trend test method. The results showed that the average WYM of the Yangtze River Basin in 1956-2015 are between 103,600 and 1,262,900 m3/km2, with an average value of 562,300 m3/km2, which is greater than the national average value of 295,000 m3/km2. The minimum value appeared in the northwestern part of the Tongtian River district, the maximum value appeared in the northeastern of Dongting Lake district. The rate of change in 1956-2015 is between -0.68/a and 0.79/a, it showed a downward trend in the western part but not significantly, an upward trend in the eastern part reached a significance level of α=0.01. The minimum value appeared in the Tongtian River district, the largest value appeared in the Hangjia Lake district, and the average tendency rate is 0.04/a in the whole basin.

Synthetic River Valleys

NASA Astrophysics Data System (ADS)

Brown, R.; Pasternack, G. B.

2011-12-01

The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

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

PubMed

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

2015-05-01

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

Spatiotemporal distribution and mass loadings of perfluoroalkyl substances in the Yangtze River of China.

PubMed

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

2014-09-15

A systematic investigation into contamination profiles of eighteen perfluoroalkyl substances (PFASs) in both surface water and sediments of Yangtze River was carried out by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in summer and winter of 2013. The total concentrations of the PFASs in the water and sediment of Yangtze River ranged from 2.2 to 74.56 ng/L and 0.05 to 1.44 ng/g dry weights (dw), respectively. The PFAS concentrations were correlated to some selected water quality parameters such as pH, total phosphorus (TP), total nitrogen (TN) and conductivity in water, and some sediment properties, such as total organic carbon (TOC), TP, and TN in sediment. The monitoring results for the water and sediment samples showed no obvious seasonal variations. Among the selected 18 PFASs, perfluorooctanoic acid (PFOA) was the dominant PFAS compound found both in water and sediment for the two seasons with its maximum concentration of 18.03 ng/L in water and 0.72 ng/g in sediment, followed by perfluorobutane sulfonic acid (PFBS) with its maximum concentration of 41.9 ng/L in water in Wuhan, whereas the lowest concentrations of PFASs were observed at Poyang lake. The annual loadings of PFOA, perfluorohexanoic acid (PFHxA), PFBS, perfluorooctane sulfonic acid (PFOS) and the total PFASs in the Yangtze River were 6.8 tons, 2.2 tons, 8.2 tons, 0.88 tons, and 20.7 tons, respectively. Wuhan and Er'zhou of Hubei contributed the most amounts of PFASs into the Yangtze River. A correlation was found between some PFASs, for example PFBS and PFOS, which suggests that both of these PFASs originate from common sources in the region. Copyright © 2014 Elsevier B.V. All rights reserved.

Channel morphology and its impact on flood passage, the Tianjiazhen reach of the middle Yangtze River

NASA Astrophysics Data System (ADS)

Shi, Yafeng; Zhang, Qiang; Chen, Zhongyuan; Jiang, Tong; Wu, Jinglu

2007-03-01

The Tianjiazhen reach of the middle Yangtze is about 8 km long, and characterized by a narrow river width of 650 m and local water depth of > 90 m in deep inner troughs, of which about 60 m is below the mean sea level. The troughs in the channel of such a large river are associated with regional tectonics and local lithology. The channel configuration plays a critical role in modifying the height and duration of river floods and erosion of the riverbed. The formation of the troughs in the bed of the Yangtze is considered to be controlled by sets of NW-SE-oriented neotectonic fault zones, in which some segments consist of highly folded thick Triassic limestone crossed by the Yangtze River. Several limestone hills, currently located next to the river channel, serve as nodes that create large vortices in the river, thereby accelerating downcutting on the riverbed composed of limestone highly susceptible to physical corrosion and chemical dissolution. Hydrological records indicate that the nodal hills and channel configuration at Tianjiazhen do not impact on normal flow discharges but discharges > 50,000 m 3s - 1 are slowed down for 2-3 days. Catastrophic floods are held up for even longer periods. These inevitably result in elevated flood stages upstream of prolonged duration, affecting large cities such as Wuhan and a very large number of people.

A monitoring study of the 1998 rainstorm along the Yangtze River of China by using TIPEX data

NASA Astrophysics Data System (ADS)

Wang, Jizhi; Yang, Yuanqin; Xu, Xiangde; Zhang, Guangzhi

2003-05-01

Plateau indicates that alternating changes of high and low water vapor distribution over the Tibetan Plateau reveals clearly that the sub-synoptic scale waves exist, whose lifetime is on the order of the hours. The revelation of the eastward motion of mesoscale waves from the Tibetan Plateau indicates that the plateau systems obviously influenced the rainstorms over the Yangtze River valley in 1998.

Interdecadal Connection Between Artic Temperature and Summer Precipitation Over the Yangtze River Valley in the CMIP5 Historical Simulations

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

Li, Yuefeng; Leung, Lai-Yung R.; Xiao, Ziniu

2013-10-01

This study assesses the ability of the Phase 5 Coupled Model Intercomparison Project (CMIP5) simulations in capturing the interdecadal precipitation enhancement over the Yangtze River valley (YRV) and investigates the contributions of Arctic warming to the interdecadal variability of the East Asian summer monsoon rainfall. Six CMIP5 historical simulations including models from Canada (CCCma), China (BCC), Germany (MPI-M), Japan (MRI), United Kingdom (MOHC), and United States (NCAR) are used. The NCEP/NCAR reanalysis and observed precipitation are also used for comparison. Among the six CMIP5 simulations, only CCCma can approximately simulate the enhancement of interdecadal summer precipitation over the YRV inmore » 1990-2005 relative to 1960-1975, and the relationships between the summer precipitation with surface temperature (Ts), the 850hPa winds, and 500hPa height field (H500), and between Ts and H500 using regression, correlation, and SVD analyses. It is found that CCCma can reasonably simulate the interdecadal surface warming over the boreal mid-to high latitudes and the Arctic in winter, spring and summer. The summer Baikal blocking appears to be the bridge that links the winter and spring surface warming over the mid-to high latitude and Arctic with the enhancement of summer precipitation over the YRV. Models that missed some or all of these relationships found in CCCma and the reanalysis failed to simulate the interdecadal enhancement of precipitation over the YRV. This points to the importance of high latitude and Arctic processes on interdecadal variability of the East Asian summer monsoon and the challenge for global climate models to correctly simulate the linkages.« less

[Study on distribution and countermeasures of Oncomelania snails in beach wetlands of Runzhou section of lower reaches of Yangtze River].

PubMed

Xia, Ai; Huang, Yixin; Jiang, Jun; Zhou, Ya-Min; Hang, De-rong; Tao, Heng-ye

2014-04-01

To understand the distribution of the river beach wetlands and Oncomelania snails in the lower reaches of the Yangtze River, and explore the countermeasures of snail control. The river beach wetlands outside the Yangtze River levee were investigated and classified according to the hierarchical and classification system of wetlands of China. The snail survey was carried out in the beach wetlands of Runzhou section of lower reaches of the Yangtze River from 2004 to 2013. The change trend of snail areas and the densities was analyzed in the wetlands. The river beach of Runzhou section of lower reaches of the Yangtze River belongs to the riverine wetland. There was Oncomelania snail breeding except the permanent water area. At present, there were natural wetlands of 1303.0 hm2, human-made wetlands of 1479.0 hmb2 and wetland function changes of 1059.0 hm2 in the river beach of Runzhou section. There was the snail area of 181.4 hm2 in the natural wetland in 2013. The area of snail control by the molluscicide and environmental modification was 4624.55 hm2 from 2004 to 2013. The decline rates of snail areas and densities were 66.53% and 77.66% respectively. The existing Oncomelania snails were distributed in the natural wetlands. The human-made wetland is helpful to snail control. The snail control in the river beach wetlands should attach a great importance to the protection of wetland ecology.

Risk and toxicity assessments of heavy metals in sediments and fishes from the Yangtze River and Taihu Lake, China.

PubMed

Fu, Jie; Hu, Xin; Tao, Xiancong; Yu, Hongxia; Zhang, Xiaowei

2013-11-01

Heavy metal pollution is one of the most serous environmental issues globally. To evaluate the metal pollution in Jiangsu Province of China, the total concentrations of heavy metals in sediments and fishes from the Yangtze River and Taihu Lake were analyzed. Ecological risk of sediments and human health risk of fish consumption were assessed respectively. Furthermore, toxicity of samples on expression of the stress responsive genes was evaluated using microbial live cell-array method. The results showed that the heavy metals concentrations in sediments from the Yangtze River were much higher than those in sediments from the Taihu Lake. However, the fishes from the Taihu Lake had higher concentrations of heavy metals than fishes from the Yangtze River. Ecological risk evaluation showed that the heavy metal contaminants in sediments from the Yangtze River posed higher risk of adverse ecological effects, while sediments from the study areas of Taihu Lake were relatively safe. Health risk assessment suggested that the heavy metals in fishes of both Yangtze River and Taihu Lake might have risk of adverse health effects to human. The toxicity assessment indicated that the heavy metals in these sediments and fishes showed transcriptional effects on the selected 21 stress responsive genes, which were involved in the pathways of DNA damage response, chemical stress, and perturbations of electron transport. Together, this field investigation combined with chemical analysis, risk assessment and toxicity bioassay would provide useful information on the heavy metal pollution in Jiangsu Province. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Prevalence of hypertension and its influencing factors in rural areas along the Yangtze River in Anhui Province in 2014-2015].

PubMed

Hu, Mingjun; Zhou, Mengmeng; Yang, Yuwei; Liang, Ling; Zhong, Qi; Qin, Qirong; Wang, Xiaodong; Huang, Fen

2017-11-01

To investigate the prevalence, awareness, treatment, control and related influence factors of hypertension among rural adult residents in areas along the Yangtze River in Anhui Province. Totally 2873 rural adult residents in seven typical towns along the Yangtze River of Chizhou, Tongling and Ma'anshan Cities, Anhui Province were selected, with multistage-stratified random cluster sampling, to perform questionnaires and physical measurements from year 2014 to 2015. The prevalence of hypertension was 30. 7%( standardized prevalence was 18. 4%), the awareness rate was 50. 6%( standardized rate was 29. 0%), the treatment rate was40. 4%( standardized rate was 18. 7%), the control rate was 17. 7%( standardized ratewas 9. 3%) in rural areas along the Yangtze River in Anhui Province. The prevalence, awareness, treatment and control rates of hypertension were increased with age increase. Abdominal obesity( OR = 1. 855, 95% CI 1. 467-2. 344), family history of hypertension( OR = 1. 594, 95% CI 1. 265-2. 008), the average annual household income < 60 000 yuan and increased BMI were risk factors of hypertension in rural areas along the Yangtze River. Female( OR = 0. 734, 95% CI 0. 604-0. 891) was its protective factors. While the factors of awareness, treatment and control rates of hypertension were not same. The prevalence of hypertension is higher in the areas along the Yangtze River in Anhui Province. However, the awareness, treatment and control rate of hypertension are lower.

Effect of water flux and sediment discharge of the Yangtze River on PAHs sedimentation in the estuary.

PubMed

Li, Rufeng; Feng, Chenghong; Wang, Dongxin; He, Maozhi; Hu, Lijuan; Shen, Zhenyao

2016-12-01

Historical distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) and their carriers (i.e., organic matter and mineral particles) in the sediment cores of the Yangtze Estuary were investigated, with emphasis laid on the role of the Yangtze River. Grain size component of sediments (clay, silt, and sand) and organic carbon (black carbon and total organic carbon) in the sediment cores were markedly affected by water flux and sediment discharge of the Yangtze River. Qualitative and quantitative analysis results showed that sands and black carbon acted as the main carriers of PAHs. The sedimentation of two-ring to three-ring PAHs in the estuary had significant correlations with water flux and sediment discharge of the Yangtze River. The relative lower level of the four-ring and five-ring to six-ring PAHs concentrations appeared around the year 2003 and remained for the following several years. This time period accorded well with the water impoundment time of the Three Gorges Reservoir. The decreased level of two-ring to three-ring PAHs occurred in the year 1994, and the peak points around the year 2009 indicated that PAHs sedimentation in the estuary also had close relationship to severe drought and flood in the catchments. The findings presented in this paper could provide references for assessing the impacts of water flux and sediment discharge on the historical deposition of PAHs and their carriers in the Yangtze Estuary.

Impact of climate change on the streamflow hydrology of the Yangtze River in China

USDA-ARS?s Scientific Manuscript database

Tuotuo River basin, the source region of the Yangtze River, is the key area, where the impact of climate change has been observed on many of the hydrological processes of this central region of the Tibetan Plateau. In this study, we examined six global climate models (GCMs) under three Respectively ...

DNA barcoding and evaluation of genetic diversity in Cyprinidae fish in the midstream of the Yangtze River.

PubMed

Shen, Yanjun; Guan, Lihong; Wang, Dengqiang; Gan, Xiaoni

2016-05-01

The Yangtze River is the longest river in China and is divided into upstream and mid-downstream regions by the Three Gorges (the natural barriers of the Yangtze River), resulting in a complex distribution of fish. Dramatic changes to habitat environments may ultimately threaten fish survival; thus, it is necessary to evaluate the genetic diversity and propose protective measures. Species identification is the most significant task in many fields of biological research and in conservation efforts. DNA barcoding, which constitutes the analysis of a short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) sequence, has been widely used for species identification. In this study, we collected 561 COI barcode sequences from 35 fish from the midstream of the Yangtze River. The intraspecific distances of all species were below 2% (with the exception of Acheilognathus macropterus and Hemibarbus maculatus). Nevertheless, all species could be unambiguously identified from the trees, barcoding gaps and taxonomic resolution ratio values. Furthermore, the COI barcode diversity was found to be low (≤0.5%), with the exception of H. maculatus (0.87%), A. macropterus (2.02%) and Saurogobio dabryi (0.82%). No or few shared haplotypes were detected between the upstream and downstream populations for ten species with overall nucleotide diversities greater than 0.00%, which indicated the likelihood of significant population genetic structuring. Our analyses indicated that DNA barcoding is an effective tool for the identification of cyprinidae fish in the midstream of the Yangtze River. It is vital that some protective measures be taken immediately because of the low COI barcode diversity.

Remote sensing of cloud distributions over the Bayanhar Mountains - Watershed of the Yangtze and Yellow rivers

NASA Technical Reports Server (NTRS)

Hung, R. J.; Liu, J. M.; Dodge, J. C.; Smith, R. E.

1986-01-01

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

Mutagenicity and estrogenicity of raw water and drinking water in an industrialized city in the Yangtze River Delta.

PubMed

Xiao, Sanhua; Lv, Xuemin; Zeng, Yifan; Jin, Tao; Luo, Lan; Zhang, Binbin; Zhang, Gang; Wang, Yanhui; Feng, Lin; Zhu, Yuan; Tang, Fei

2017-10-01

Public concern was aroused by frequently reported water pollution incidents in Taihu Lake and the Yangtze River. The pollution also caught and sustained the attention of the scientific community. From 2010 to 2016, raw water and drinking water samples were continually collected at Waterworks A and B (Taihu Lake) and Waterworks C (Yangtze River). The non-volatile organic pollutants in the water samples were extracted by solid phase extraction. Ames tests and yeast estrogen screen (YES) assays were conducted to evaluate the respective mutagenic and estrogenic effects. Water samples from the Yangtze River-based Waterworks C possessed higher mutagenicity than those from Taihu Lake-based Waterworks A (P＜0.001) and Waterworks B (P = 0.026). Water treatment enhanced the direct mutagenicity (P = 0.022), and weakened the estrogenicity of the raw water (P＜0.001) with a median removal rate of 100%. In fact, very few of the finished samples showed estrogenic activity. Raw water samples from Waterworks A showed weaker estrogenicity than those from Waterworks B (P = 0.034) and Waterworks C (P = 0.006). In summary, mutagenic effects in drinking water and estrogenic effects in raw water merited sustained attention. The Yangtze River was more seriously polluted by mutagenic and estrogenic chemicals than Taihu Lake was. Copyright © 2017 Elsevier Ltd. All rights reserved.

27 CFR 9.214 - Haw River Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Haw River Valley. 9.214... River Valley. (a) Name. The name of the viticultural area described in this section is “Haw River Valley”. For purposes of part 4 of this chapter, “Haw River Valley” and “Haw River” are terms of viticultural...

Mid-Holocene palaeoflood events recorded at the Zhongqiao Neolithic cultural site in the Jianghan Plain, middle Yangtze River Valley, China

NASA Astrophysics Data System (ADS)

Wu, Li; Zhu, Cheng; Ma, Chunmei; Li, Feng; Meng, Huaping; Liu, Hui; Li, Linying; Wang, Xiaocui; Sun, Wei; Song, Yougui

2017-10-01

Palaeo-hydrological and archaeological investigations were carried out in the Jianghan Plain in the middle reaches of the Yangtze River. Based on a comparative analysis of modern flood sediments and multidisciplinary approaches such as AMS14C and archaeological dating, zircon micromorphology, grain size, magnetic susceptibility, and geochemistry, we identified palaeoflood sediments preserved at the Zhongqiao archaeological site. The results indicate that three palaeoflood events (i.e. 4800-4597, 4479-4367, and 4168-3850 cal. yr BP) occurred at the Zhongqiao Site. Comparisons of palaeoflood deposit layers at a number of Neolithic cultural sites show that two extraordinary palaeoflood events occurred in the Jianghan Plain during approximately 4900-4600 cal. yr BP (i.e.mid-late Qujialing cultural period) and 4100-3800 cal. yr BP (i.e. from late Shijiahe cultural period to the Xia Dynasty). Further analysis of the environmental context suggests that these flooding events might have been connected with great climate variability during approximately 5000-4500 cal. yr BP and at ca. 4000 cal. yr BP. These two palaeoflood events were closely related to the expansion of the Jianghan lakes driven by the climatic change, which in turn influenced the rise and fall of the Neolithic cultures in the middle reaches of the Yangtze River. Other evidence also suggests that the intensified discrepancy between social development and environmental change processes (especially the hydrological process) during the late Shijiahe cultural period might be the key factor causing the collapse of the Shijiahe Culture. The extraordinary floods related to the climatic anomaly at ca. 4000 cal. yr BP and political conflicts from internal or other cultural areas all accelerated the collapse of the Shijiahe Culture.

Predictability of current and future multi-river discharges: Ganges, Brahmaputra, Yangtze, Blue Nile, and Murray-Darling rivers

NASA Astrophysics Data System (ADS)

Jian, Jun

2007-12-01

Determining river discharge is of critical importance to many societies as they struggle with fresh water supply and risk of flooding. In Bangladesh, floods occur almost every year but with sufficient irregularity to have adverse social and economical consequences. Important goals are to predict the discharge to be used for the optimization of agricultural practices, disaster mitigation and water resource management. The aim of this study is to determine the predictability of river discharge in a number of major rivers on time scale varying from weeks to a century. We investigated predictability considering relationship between SST and discharge. Next, we consider IPCC model projections of river discharge while the models are statistically adjusted against observed discharges. In this study, we consider five rivers, the Ganges, the Brahmaputra, the Yangtze, the Blue Nile, and the Murray-Darling Rivers. On seasonal time scales, statistically significant correlations are found between mean monthly equatorial Pacific sea surface temperature (SST) and the summer Ganges discharge with lead times of 2-3 months due to oscillations of the El Nino-Southern Oscillation (ENSO) phenomena. In addition, there are strong correlations in the southwest and northeast Pacific. These, too, appear to be tied to the ENSO cycle. The Brahmaputra discharge, on the other hand, shows somewhat weaker relationships with tropical SST. Strong lagged correlations relationships are found with SST in the Bay of Bengal but these are the result of very warm SSTs and exceptional Brahmaputra discharge during the summer of 1998. When this year is removed from the time series, relationships weaken everywhere except in the northwestern Pacific for the June discharge and in areas of the central Pacific straddling the equator for the July discharge. The relationships are relative strong, but they are persistent from month to month and suggest that two different and sequential factors influence Brahmaputra

Response of the turbidity maximum zone in the Yangtze River Estuary due to human activities during the dry season.

PubMed

Chen, Xiaofeng; Shen, Zhenyao; Yang, Ye

2016-09-01

The interaction between a river and the sea results in a turbidity maximum zone (TMZ) within the estuary, which has a great impact on the local ecosystem. In the Yangtze River Estuary, the magnitude and extent of the TMZ vary with water discharge. In this study, the cumulative human activity altered the water discharge regime from the river to the estuary. In the post-Three Gorges Dam (TGD) period, water discharge increased by 35.10 % at Datong in February compared with that in the pre-TGD period. The effects of water discharge variation on the characteristics of the TMZ were analyzed during spring and neap tidal periods using the three-dimensional environmental fluid dynamic code (EFDC) model. The area of the TMZ decreased by 3.11 and 17.39 % during neap and spring tides, respectively. In addition, the upper limit of the TMZ moved 11.68 km seaward during neap tide, whereas the upper limit of the TMZ in the upstream and downstream areas moved seaward 9.65 and 2.34 km, respectively, during spring tide. These findings suggest that the area and location of the TMZ are more sensitive to upstream runoff during spring tide than during neap tide. These changes in the TMZ will impact the biochemical processes in the Yangtze River Estuary. In the foreseeable future, the distribution characteristic of TMZ will inevitably change due to variations in the Yangtze River discharge resulting from new human activities (i.e., new dams), which are being constructed upstream in the Yangtze River system.

Yangtze River, an insignificant genetic boundary in tufted deer (Elaphodus cephalophus): the evidence from a first population genetics study.

PubMed

Sun, Zhonglou; Pan, Tao; Wang, Hui; Pang, Mujia; Zhang, Baowei

2016-01-01

Great rivers were generally looked at as the geographical barrier to gene flow for many taxonomic groups. The Yangtze River is the third largest river in the world, and flows across South China and into the East China Sea. Up until now, few studies have been carried out to evaluate its effect as a geographical barrier. In this study, we attempted to determine the barrier effect of the Yangtze River on the tufted deer ( Elaphodus cephalophus ) using the molecular ecology approach. Using mitochondrial DNA control region (CR) sequences and 13 nuclear microsatellite loci, we explored the genetic structure and gene flow in two adjacent tufted deer populations (Dabashan and Wulingshan populations), which are separated by the Yangtze River. Results indicated that there are high genetic diversity levels in the two populations, but no distinguishable haplotype group or potential genetic cluster was detected which corresponded to specific geographical population. At the same time, high gene flow was observed between Wulingshan and Dabashan populations. The tufted deer populations experienced population decrease from 0.3 to 0.09 Ma BP, then followed by a distinct population increase. A strong signal of recent population decline ( T = 4,396 years) was detected in the Wulingshan population by a Markov-Switching Vector Autoregressions(MSVAR) process population demography analysis. The results indicated that the Yangtze River may not act as an effective barrier to gene flow in the tufted deer. Finally, we surmised that the population demography of the tufted deer was likely affected by Pleistocene climate fluctuations and ancient human activities.

Evaluation of the ecotoxicity of sediments from Yangtze river estuary and contribution of priority PAHs to ah receptor--mediated activities.

PubMed

Liu, Li; Chen, Ling; Shao, Ying; Zhang, Lili; Floehr, Tilman; Xiao, Hongxia; Yan, Yan; Eichbaum, Kathrin; Hollert, Henner; Wu, Lingling

2014-01-01

In this study, in vitro bioassays were performed to assess the ecotoxicological potential of sediments from Yangtze River estuary. The cytotoxicity and aryl hydrocarbon receptor (AhR)-mediated toxicity of sediment extracts with rainbow trout (Oncorhynchus mykiss) liver cells were determined by neutral red retention and 7-ethoxyresorufin-O-deethylase assays. The cytotoxicity and AhR-mediated activity of sediments from the Yangtze River estuary ranged from low level to moderate level compared with the ecotoxicity of sediments from other river systems. However, Yangtze River releases approximately 14 times greater water discharge compared with Rhine, a major river in Europe. Thus, the absolute pollution mass transfer of Yangtze River may be detrimental to the environmental quality of estuary and East China Sea. Effect-directed analysis was applied to identify substances causing high dioxin-like activities. To identify unknown substances contributing to dioxin-like potencies of whole extracts, we fractionated crude extracts by open column chromatography. Non-polar paraffinic components (F1), weakly and moderately polar components (F2), and highly polar substances (F3) were separated from each crude extract of sediments. F2 showed the highest dioxin-like activities. Based on the results of mass balance calculation of chemical toxic equivalent concentrations (TEQs), our conclusion is that priority polycyclic aromatic hydrocarbons indicated a low portion of bio-TEQs ranging from 1% to 10% of crude extracts. Further studies should be conducted to identify unknown pollutants.

Evaluation of the Ecotoxicity of Sediments from Yangtze River Estuary and Contribution of Priority PAHs to Ah Receptor-Mediated Activities

PubMed Central

Liu, Li; Chen, Ling; Shao, Ying; Zhang, Lili; Floehr, Tilman; Xiao, Hongxia; Yan, Yan; Eichbaum, Kathrin; Hollert, Henner; Wu, Lingling

2014-01-01

In this study, in vitro bioassays were performed to assess the ecotoxicological potential of sediments from Yangtze River estuary. The cytotoxicity and aryl hydrocarbon receptor (AhR)-mediated toxicity of sediment extracts with rainbow trout (Oncorhynchus mykiss) liver cells were determined by neutral red retention and 7-ethoxyresorufin-O-deethylase assays. The cytotoxicity and AhR-mediated activity of sediments from the Yangtze River estuary ranged from low level to moderate level compared with the ecotoxicity of sediments from other river systems. However, Yangtze River releases approximately 14 times greater water discharge compared with Rhine, a major river in Europe. Thus, the absolute pollution mass transfer of Yangtze River may be detrimental to the environmental quality of estuary and East China Sea. Effect-directed analysis was applied to identify substances causing high dioxin-like activities. To identify unknown substances contributing to dioxin-like potencies of whole extracts, we fractionated crude extracts by open column chromatography. Non-polar paraffinic components (F1), weakly and moderately polar components (F2), and highly polar substances (F3) were separated from each crude extract of sediments. F2 showed the highest dioxin-like activities. Based on the results of mass balance calculation of chemical toxic equivalent concentrations (TEQs), our conclusion is that priority polycyclic aromatic hydrocarbons indicated a low portion of bio-TEQs ranging from 1% to 10% of crude extracts. Further studies should be conducted to identify unknown pollutants. PMID:25111307

Variations of Runoff and Sediment Load in the Middle and Lower Reaches of the Yangtze River, China (1950-2013)

PubMed Central

Li, Na; Wang, Lachun; Zeng, Chunfen; Wang, Dong; Liu, Dengfeng; Wu, Xutong

2016-01-01

On the basis of monthly runoff series obtained in 1950–2013 and annual sediment load measured in 1956–-2013 at five key hydrological stations in the middle and lower reaches of the Yangtze River basin, this study used the Mann-Kendall methods to identify trend and abrupt changes of runoff and sediment load in relation to human activities. The results were as follows: (1) The annual and flood season runoffs showed significant decreasing trends at Yichang station, and showed slight downward trends at Hankou and Datong stations, while the abrupt changes of dry season runoff at Yichang, Hankou and Datong stations occurred in about 2007 and the change points were followed by significant increasing trends. The construction of the Three Gorges Dam, which began to operate in 2003, influenced the variations of runoff in the mainstream of Yangtze River, but the effect weakened with the distance along the downstream direction from TGD. (2) Since the 1990s, annual sediment loads at Yichang, Hankou, and Datong stations have been decreasing significantly, and after 2002, the annual sediment load at Yichang dropped below that of Hankou and Datong. The dams and deforestation/forestation contributed to the significant decreasing trend of the sediment load. In addition, the Three Gorges Dam aggravated the downward trend and caused the erosion of the riverbed and riverbanks in the middle and lower reaches. (3) The runoff and sediment load flowing from Dongting Lake into the mainstream of the Yangtze River showed significant decreasing trends at Chenglingji station after 1970s, and in contrast, slight increase in the sediment flow from Poyang Lake to the mainstream of the Yangtze River at Hukou station were detected over the post-TGD period (2003–2013). The result of the study will be an important foundation for watershed sustainable development of the Yangtze River under the human activities. PMID:27479591

Variations of Runoff and Sediment Load in the Middle and Lower Reaches of the Yangtze River, China (1950-2013).

PubMed

Li, Na; Wang, Lachun; Zeng, Chunfen; Wang, Dong; Liu, Dengfeng; Wu, Xutong

2016-01-01

On the basis of monthly runoff series obtained in 1950-2013 and annual sediment load measured in 1956--2013 at five key hydrological stations in the middle and lower reaches of the Yangtze River basin, this study used the Mann-Kendall methods to identify trend and abrupt changes of runoff and sediment load in relation to human activities. The results were as follows: (1) The annual and flood season runoffs showed significant decreasing trends at Yichang station, and showed slight downward trends at Hankou and Datong stations, while the abrupt changes of dry season runoff at Yichang, Hankou and Datong stations occurred in about 2007 and the change points were followed by significant increasing trends. The construction of the Three Gorges Dam, which began to operate in 2003, influenced the variations of runoff in the mainstream of Yangtze River, but the effect weakened with the distance along the downstream direction from TGD. (2) Since the 1990s, annual sediment loads at Yichang, Hankou, and Datong stations have been decreasing significantly, and after 2002, the annual sediment load at Yichang dropped below that of Hankou and Datong. The dams and deforestation/forestation contributed to the significant decreasing trend of the sediment load. In addition, the Three Gorges Dam aggravated the downward trend and caused the erosion of the riverbed and riverbanks in the middle and lower reaches. (3) The runoff and sediment load flowing from Dongting Lake into the mainstream of the Yangtze River showed significant decreasing trends at Chenglingji station after 1970s, and in contrast, slight increase in the sediment flow from Poyang Lake to the mainstream of the Yangtze River at Hukou station were detected over the post-TGD period (2003-2013). The result of the study will be an important foundation for watershed sustainable development of the Yangtze River under the human activities.

Attribution of extreme precipitation in the lower reaches of the Yangtze River during May 2016

NASA Astrophysics Data System (ADS)

Li, Chunxiang; Tian, Qinhua; Yu, Rong; Zhou, Baiquan; Xia, Jiangjiang; Burke, Claire; Dong, Buwen; Tett, Simon F. B.; Freychet, Nicolas; Lott, Fraser; Ciavarella, Andrew

2018-01-01

May 2016 was the third wettest May on record since 1961 over central eastern China based on station observations, with total monthly rainfall 40% more than the climatological mean for 1961-2013. Accompanying disasters such as waterlogging, landslides and debris flow struck part of the lower reaches of the Yangtze River. Causal influence of anthropogenic forcings on this event is investigated using the newly updated Met Office Hadley Centre system for attribution of extreme weather and climate events. Results indicate that there is a significant increase in May 2016 rainfall in model simulations relative to the climatological period, but this increase is largely attributable to natural variability. El Niño years have been found to be correlated with extreme rainfall in the Yangtze River region in previous studies—the strong El Niño of 2015-2016 may account for the extreme precipitation event in 2016. However, on smaller spatial scales we find that anthropogenic forcing has likely played a role in increasing the risk of extreme rainfall to the north of the Yangtze and decreasing it to the south.

Terrestrial Contributions to the Aquatic Food Web in the Middle Yangtze River

PubMed Central

Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

2014-01-01

Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies. PMID:25047656

Terrestrial contributions to the aquatic food web in the middle Yangtze River.

PubMed

Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

2014-01-01

Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

A magnetic record of heavy metal pollution in the Yangtze River subaqueous delta.

PubMed

Dong, Chenyin; Zhang, Weiguo; Ma, Honglei; Feng, Huan; Lu, Honghua; Dong, Yan; Yu, Lizhong

2014-04-01

The rapid industrial development in the Yangtze River watershed over the last several decades has drawn great attention with respect to heavy metal pollution to the Yangtze River estuary and nearby coastal areas. In this study, a 236 cm long sediment core was retrieved from the Yangtze River subaqueous delta (122°36' E, 31°00' N) in 2008 and analyzed for magnetic properties and geochemical compositions to investigate heavy metal pollution history. The activity of (137)Cs peaked at depth 140 cm, with a broad plateau between 120 cm and 140 cm, suggesting an average sedimentation rate of 3.11 cm yr(-1) for the upper 140 cm layer. Magnetic susceptibility (χ), saturation isothermal remanent magnetization (SIRM), anhysteretic remanent magnetization (χARM) and heavy metal enrichment factors (EF) all showed an upward increase trend above depth 140 cm, suggesting that increased ferrimagnetic mineral concentration was accompanied by heavy metal enrichment in the sediment. Geochemical and granolumetric analyses showed that sediment sources and particle sizes played minor roles in the variations of magnetic properties. The effect of diagenesis, which can lead to the selective removal of magnetic minerals, was noticeable in the lower part of the core (140-236 cm). Co-variation between magnetic properties (χ, SIRM and χARM) and EF of Cu and Pb suggests that the elevated ferrimagnetic mineral concentration can be used as an indicator of heavy metal pollution in the reconstruction of environmental changes in estuarine and coastal settings. Copyright © 2014. Published by Elsevier B.V.

Three-dimensional Virtual Simulation of Oil Spill of Yangtze River in Chongqing Area Based on Emergency Decision

NASA Astrophysics Data System (ADS)

Chen, Shuzhe; Huang, Liwen

the river of Yangtze River in Chongqing area is continuous curved. Hydrology and channel situation is complex, and the transportation is busy. With the increasing of shipments of hazardous chemicals year by year, oil spill accident risk is rising. So establishment of three-dimensional virtual simulation of oil spill and its application in decision-making has become an urgent task. This paper detailed the process of three-dimensional virtual simulation of oil spill and established a system of three-dimensional virtual Simulation of oil spill of Yangtze River in Chongqing area by establishing an oil spill model of the Chongqing area based on oil particles model, and the system has been used in emergency decision to provide assistance for the oil spill response.

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

PubMed Central

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

2015-01-01

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

Synergistic contribution of precipitation anomalies over northwestern India and the South China Sea to high temperature over the Yangtze River Valley

NASA Astrophysics Data System (ADS)

Liu, Ge; Wu, Renguang; Sun, Shuqing; Wang, Huimei

2015-09-01

This study explores the characteristics of high temperature anomalies over eastern China and associated influencing factors using observations and model outputs. Results show that more long-duration (over 8 days) high temperature events occur over the middle and lower reaches of the Yangtze River Valley (YRV) than over the surrounding regions, and control most of the interannual variation of summer mean temperature in situ. The synergistic effect of summer precipitation over the South China Sea (SCS) region (18°-27°N, 115°-124°E) and the northwestern India and Arabian Sea (IAS) region (18°-27°N, 60°-80°E) contributes more significantly to the variation of summer YRV temperature, relative to the respective SCS or IAS precipitation anomaly. More precipitation (enhanced condensational heating) over the SCS region strengthens the western Pacific subtropical high (WPSH) and simultaneously weakens the westerly trough over the east coast of Asia, and accordingly results in associated high temperature anomalies over the YRV region through stimulating an East Asia-Pacific (EAP) pattern. More precipitation over the IAS region further adjusts the variations of the WPSH and westerly trough, and eventually reinforces high temperature anomalies over the YRV region. Furthermore, the condensational heating related to more IAS precipitation can adjust upper-tropospheric easterly anomalies over the YRV region by exciting a circumglobal teleconnection, inducing cold horizontal temperature advection and related anomalous descent, which is also conducive to the YRV high temperature anomalies. The reproduction of the above association in the model results indicates that the above results can be explained both statistically and dynamically.

Future Earth Coasts: The Mississippi and Yangtze Rivers as Examples

NASA Astrophysics Data System (ADS)

D'Elia, C.; Xu, K.; Chen, Z.; Day, J.; Le Tissier, M.

2016-02-01

Deltas and estuaries are productive and fertile links between the land and the sea. Deltas occupy only about 5% of the Earth's surface but sustain over a half billion people all around the world. Many river deltas are endangered because of extensive dam and levee construction, declining sediment supply, groundwater withdrawal, relative sea level rise and severe coastal erosion, leading to a variety of threats to natural, economic and social systems. About 630 million people now live at an elevation of 10 m or less above mean sea level, and maintaining sustainable land with a rising sea will be a challenging problem for many major deltaic coasts and cities in the next century. Stemming from 20 years of LOICZ (Land-Ocean Interactions in the Coastal Zone), Future Earth Coasts is a new global initiative that seeks to enable the scientific and social scientific communities to build knowledge through collaborative processes to better understand and address the profound and urgent changes occurring in vulnerable coastal zones. The topics of this comparative study are the Mississippi and Yangtze (Changjiang) Rivers, the largest in the United States and China, respectively. We use these two rivers as examples to evaluate current conditions and catalyze future discussion. The Mississippi and Yangtze both have had long-term observations of physical and biological processes that affect human activities, making it possible to quantify both natural and anthropogenic impacts. We also consider the limits to concept of sustainability for the Earth's biosphere and human civilization, and emphasize biophysical constraints and demographic challenges.

[Study of the fluorescence characteristics of DOM from the Yangtze River and Jialing River around Chongqing's urban areas].

PubMed

Ji, Fang-ying; Li, Si; Zhou, Guang-ming; Yu, Dan-ni; Wang, Tu-jin; Cao, Lin; Tan, Xue-mei; Yang, Da-cheng; Zhou, Xiao-yi

2010-01-01

The fluorescence emission and excitation emission matrix (EEM) technologies were used to characterize the dissolved organic matter (DOM) in the water body of the Yangtze River and Jialing River around the Chongqing urban areas from April to August 2008. Concerning about the accidents of the Wenchuan's Earthquake in May and Tangjiashan Yansaihu's effects in June, and the high water period time in the summer in two months of July and August, from the EEM obtained from each sampling station and time, the composition, distribution and their changing features of the DOM in the two rivers were investigated as combined with the water samples' environmental parameters such as pH, DO, DOC with EEM's fingerprint features, f(450/500) etc; finally the bio-environment behavior effects of the three types of fluorescence peaks were elaborated, where humic-like, fulvic-like, and protein-like from the five sampling stations' EEMs during the five months were given detailed representation. From the experimental results obtained, the fluorescence peaks are mainly composed of two types of fluorophores: humic-like and protein-like in the two rivers around the Chongqing urban areas during the investigation in five months, the protein-like's peaks value in Jialing River is higher than the values in the Yangtze River, and all the fluorescence peaks in the two Rivers' water body decrease more or less after the two Rivers join in Chun Tan sampling station; the protein-like peak is notably higher after the "5 x 12" earthquake period time including May and June and high water period time, which mainly originated from terrestrial sources, but its intensities decreased observably while the water bodies of the two rivers joining together in the Chao Tianmen and Chun Tan's sampling station.

Case study on rehabilitation of a polluted urban water body in Yangtze River Basin.

PubMed

Wu, Juan; Cheng, Shuiping; Li, Zhu; Guo, Weijie; Zhong, Fei; Yin, Daqiang

2013-10-01

In the past three decades, the fast development of economy and urbanization has caused increasingly severe pollutions of urban water bodies in China. Consequently, eutrophication and deterioration of aquatic ecosystem, which is especially significant for aquatic vegetation, inevitably became a pervasive problem across the Yangtze River Basin. To rehabilitate the degraded urban water bodies, vegetation replanting is an important issue to improve water quality and to rehabilitate ecosystem. As a case study, a representative polluted urban river, Nanfeihe River, in Hefei City, Anhui Province, was chosen to be a rehabilitation target. In October 2009 and May 2010, 13 species of indigenous and prevalent macrophytes, including seven species emergent, one species floating leaved, and five species submersed macrophytes, were planted along the bank slopes and in the river. Through 1.5 years' replanting practice, the water quality and biodiversity of the river had been improved. The concentrations of total nitrogen (TN), total phosphorus (TP), and ammonia nitrogen (NH4 (+)-N) declined by 46.0, 39.5, and 60.4 %, respectively. The species of macrophytes increased from 14 to 60, and the biodiversity of phytoplankton rose significantly in the river (p<0.05). The biomasses of zooplankton and benthos were also improved after the vegetation replanting. The study confirmed that vegetation replanting could alleviate the increasing water pollution and rehabilitate the degraded aquatic ecosystem. The case study would be an example for polluted urban waters restoration in the middle-downstream area of Yangtze River Base.

Variation of Temperature and Precipitation in Urban Agglomeration and Prevention Suggestion of Waterlogging in Middle and Lower Reaches of Yangtze River

NASA Astrophysics Data System (ADS)

Na, Liu; Youjie, Jin; Jiaqi, Dai

2018-03-01

The variation trend of temperature and precipitation during flood season in the middle and lower reaches of the Yangtze River basin in recent 50 years and change characteristics of rainfall in five typical flood prone cities are analysed. Aiming at waterlogging problems in the urban agglomeration of middle and lower reaches of the Yangtze River, the comprehensive prevention and control suggestions are put forward. The results showed that: the temperature trend in the basin decreased and then increased, and the precipitation showed a downward-rising-downward trend, no mutation occurred; The incidence of heavy rainfall events in the five typical cities with daily rainfall more than 50mm showed an upward trend, and increased significantly after 2002. The intensity of precipitation increased gradually. Climate change makes urban agglomeration waterlogging disasters become increasingly prominent in the middle and lower reaches of the Yangtze River.

Occurrence of pharmaceuticals and personal care products and associated environmental risks in the central and lower Yangtze river, China.

PubMed

Wu, Chenxi; Huang, Xiaolong; Witter, Jason D; Spongberg, Alison L; Wang, Kexiong; Wang, Ding; Liu, Jiantong

2014-08-01

Pharmaceutical and personal care products (PPCPs) residues are being highlighted around the world as of emerging concern in surface waters. Here the occurrence of PPCPs in the central and lower Yangtze River, along with four large freshwater lakes within the river basin (Dongting, Poyang, Tai, and Chao) was reported. Fifteen out of twenty selected PPCPs were detected in the collected surface water samples. Caffeine, paraxanthine, sulfamethazine, and clindamycin were detected with 100 percent frequency in the Yangtze River. In the river, the highest average concentration was observed for erythromycin (296 ng L(-1)), followed by caffeine (142 ng L(-1)) and paraxanthine (41 ng L(-1)). In the four lakes, total PPCP concentrations were much higher in the Chao (1547 ng L(-1)) and Tai (1087 ng L(-1)) lakes compared to the Poyang (108 ng L(-1)) and Dongting (137 ng L(-1)) lakes. Lincomycin and clindamycin were most abundant in the lakes, especially in the Tai Lake. Environmental risk assessment for the worst case scenario was assessed using calculated risk quotients, and indicates a high environmental risk of erythromycin and clarithromycin in the Yangtze River, clarithromycin in the Chao Lake, and clindamycin in the Tai Lake. Copyright © 2014 Elsevier Inc. All rights reserved.

A statistical forecast model using the time-scale decomposition technique to predict rainfall during flood period over the middle and lower reaches of the Yangtze River Valley

NASA Astrophysics Data System (ADS)

Hu, Yijia; Zhong, Zhong; Zhu, Yimin; Ha, Yao

2018-04-01

In this paper, a statistical forecast model using the time-scale decomposition method is established to do the seasonal prediction of the rainfall during flood period (FPR) over the middle and lower reaches of the Yangtze River Valley (MLYRV). This method decomposites the rainfall over the MLYRV into three time-scale components, namely, the interannual component with the period less than 8 years, the interdecadal component with the period from 8 to 30 years, and the interdecadal component with the period larger than 30 years. Then, the predictors are selected for the three time-scale components of FPR through the correlation analysis. At last, a statistical forecast model is established using the multiple linear regression technique to predict the three time-scale components of the FPR, respectively. The results show that this forecast model can capture the interannual and interdecadal variation of FPR. The hindcast of FPR during 14 years from 2001 to 2014 shows that the FPR can be predicted successfully in 11 out of the 14 years. This forecast model performs better than the model using traditional scheme without time-scale decomposition. Therefore, the statistical forecast model using the time-scale decomposition technique has good skills and application value in the operational prediction of FPR over the MLYRV.

Is ENSO related to 2015 Easter Star Capsized on the Yangtze River of China?

NASA Astrophysics Data System (ADS)

Xie, P.

2015-12-01

Natural disasters have profound effects on community security and economic damage of China's Hubei province. In June 1st, 2015, a cruise ship, Easter Star, capsized on Yangtze River in Hubei province with 442 died. What reason gives rise to such strong convection causing ship sunk? Based on the wind disasters of Hubei province happened in 1963-2015, this study analyzes their features bytime-series regression, and correlates them to global El Niño/Southern Oscillation (ENSO) events. The compared results demonstrated that the wind disasters shown an increasing tendency. There are two peaks corresponding to the strongest ENSO peaks during the past 50 years; each peak lasts two-three years. The facts demonstrated an essential linear relation between the ENSO phenomena and wind disasters in Hubei province. 2015 Easter Star capsized happened at current El Niño event in 2014-2015. We also observed that the historical wind disasters appeared in seasonal variation. Over 90% events concentrated in spring and summer; very few events happened in autumn and winter. Moreover, the disasters depend on the geographic conditions. Most disasters concentrated in four zones, named as Xingshan-Baokang, Xuanen, Wufeng-Yichang, Jingzhou-Gongan, in which Xingshan and Changyang are the two most density of zones. Yangtze River provides an air flowing conduct for strong convective winds. It can be concluded that the strong convection causing 2015 Easter Star capsized is related to current global ENSO phenomenon.Keywords: ENSO, wind disaster, time-series regression analysis, Easter Star, Yangtze River, Hubei Province,

Genetic Diversity of Daphnia pulex in the Middle and Lower Reaches of the Yangtze River

PubMed Central

Wang, Wenping; Zhang, Kun; Deng, Daogui; Zhang, Ya-Nan; Peng, Shuixiu; Xu, Xiaoxue

2016-01-01

Increased human activities and environmental changes may lead to genetic diversity variations of Cladocerans in water. Daphnia pulex are distributed throughout the world and often regarded as a model organism. The 16S rDNA, cytochrome c oxidase subunit I (COI), and 18S genes were used as molecular marks. The genetic diversity and phylogeny of D. pulex obtained from 10 water bodies in the middle and lower reaches of the Yangtze River were studied. For 16S rDNA, COI gene, and 18S gene, the A+T content (65.4%, 58.4%, and 54.6%) was significantly higher than the G+C content (34.6%, 41.6% and 45.4%). This result was consistent with higher A and T contents among invertebrates. Based on the genetic distances of 16S rDNA and COI genes, the genetic differences of D. pulex from 10 water bodies located in the middle and lower reaches of the Yangtze River in China was minimal (0%–0.8% for 16S rDNA and 0%–1.5% for COI gene). However, D. pulex evolved into two branches in the phylogenetic trees, which coincided with its geographical distribution. Compared with D. pulex from other countries, the average genetic distance of D. pulex obtained from 10 water bodies in the middle and lower reaches of the Yangtze River reached 9.1%–10.5%, thereby indicating that D. pulex may have evolved into different subspecies. PMID:27015539

Decreasing reference evapotranspiration in a warming climate - A case of Changjiang (Yangtze) River catchment during 1970-2000

NASA Astrophysics Data System (ADS)

Xu, C. Y.; Gong, L. B.; Tong, J.; Chen, D. L.

2006-07-01

This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during 1970-2000 in the Yangtze River catchment. Relative contributions of the four meteorological variables to changes in the reference evapotranspiration are quantified. The results show that both the reference evapotranspiration and the pan evaporation have significant. decreasing trends in the upper, the middle as well as in the whole Changjiang (Yangtze) River catchment at the 5% significance level, while the air temperature shows a significant increasing trend. The decreasing trend detected in the reference evapotranspiration can be attributed to the significant decreasing trends in the net radiation and the wind speed.

Ship-based MAX-DOAS measurements of tropospheric NO2, SO2, and HCHO distribution along the Yangtze River

NASA Astrophysics Data System (ADS)

Hong, Qianqian; Liu, Cheng; Chan, Ka Lok; Hu, Qihou; Xie, Zhouqing; Liu, Haoran; Si, Fuqi; Liu, Jianguo

2018-04-01

In this paper, we present ship-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of tropospheric trace gases' distribution along the Yangtze River during winter 2015. The measurements were performed along the Yangtze River between Shanghai and Wuhan, covering major industrial areas in eastern China. Tropospheric vertical column densities (VCDs) of nitrogen dioxide (NO2), sulfur dioxide (SO2), and formaldehyde (HCHO) were retrieved using the air mass factor calculated by the radiative transfer model. Enhanced tropospheric NO2 and SO2 VCDs were detected over downwind areas of industrial zones over the Yangtze River. In addition, spatial distributions of atmospheric pollutants are strongly affected by meteorological conditions; i.e., positive correlations were found between concentration of pollutants and wind speed over these areas, indicating strong influence of transportation of pollutants from high-emission upwind areas along the Yangtze River. Comparison of tropospheric NO2 VCDs between ship-based MAX-DOAS and Ozone Monitoring Instrument (OMI) satellite observations shows good agreement with each other, with a Pearson correlation coefficient (R) of 0.82. In this study, the NO2 / SO2 ratio was used to estimate the relative contributions of industrial sources and vehicle emissions to ambient NO2 levels. Analysis results of the NO2 / SO2 ratio show a higher contribution of industrial NO2 emissions in Jiangsu Province, while NO2 levels in Jiangxi and Hubei provinces are mainly related to vehicle emissions. These results indicate that different pollution control strategies should be applied in different provinces. In addition, multiple linear regression analysis of ambient carbon monoxide (CO) and odd oxygen (Ox) indicated that the primary emission and secondary formation of HCHO contribute 54.4 ± 3.7 % and 39.3 ± 4.3 % to the ambient HCHO, respectively. The largest contribution from primary emissions in winter suggested that

Assessing the potential for change in the middle Yangtze River channel following impoundment of the Three Gorges Dam

NASA Astrophysics Data System (ADS)

Yuan, Wenhao; Yin, Daowei; Finlayson, Brian; Chen, Zhongyuan

2012-04-01

The geomorphic impacts of dams on downstream river channels are complex, not readily predictable for specific cases, but widely reported in the literature. For the Three Gorges Dam on the Yangtze (Changjiang) River in China, no studies of the impact of the changed flow and sediment conditions below the dam on the behaviour of the channel were included in the pre-dam feasibility report. We have assembled a database of flow and sediment data for the middle Yangtze River from Yichang to Hankou and used this to analyse changes following the closure of the dam. While total flow is little affected, the operating strategy for the dam that provides for storage of part of the summer high flows to maintain hydroelectric power generation in winter (the low flow season) is reflected in changes to the seasonal distribution of flow below the dam. We calculated potential sediment carrying capacity and compared it with measured sediment concentrations for both pre- and post-dam conditions. While channel sedimentation is indicated along the middle Yangtze for pre-dam conditions, scour is indicated for post-dam conditions, highest at Yichang immediately below the dam and decreasing downstream.

Effect of conservation efforts and ecological variables on waterbird population sizes in wetlands of the Yangtze River

PubMed Central

Zhang, Yong; Jia, Qiang; Prins, Herbert H. T.; Cao, Lei; de Boer, Willem Frederik

2015-01-01

Forage quality and availability, climatic factors, and a wetland’s conservation status are expected to affect the densities of wetland birds. However, the conservation effectiveness is often poorly studied. Here, using twelve years’ census data collected from 78 wetlands in the Yangtze River floodplain, we aimed to understand the effect of these variables on five Anatidae species, and evaluate the effectiveness of the conservation measures by comparing population trends of these species among wetlands that differ in conservations status. We showed that the slope angle of a wetland and the variation thereof best explain the differences in densities of four species. We also found that the population abundances of the Anatidae species generally declined in wetlands along the Yangtze River floodplain over time, with a steeper decline in wetlands with a lower protection status, indicating that current conservation policies might deliver benefits for wintering Anatidae species in China, as population sizes of the species were buffered to some extent against decline in numbers in wetlands with a higher level protection status. We recommend several protection measures to stop the decline of these Anatidae species in wetlands along the Yangtze River floodplain, which are of great importance for the East Asian-Australasian Flyway. PMID:26601785

Effect of conservation efforts and ecological variables on waterbird population sizes in wetlands of the Yangtze River

NASA Astrophysics Data System (ADS)

Zhang, Yong; Jia, Qiang; Prins, Herbert H. T.; Cao, Lei; de Boer, Willem Frederik

2015-11-01

Forage quality and availability, climatic factors, and a wetland’s conservation status are expected to affect the densities of wetland birds. However, the conservation effectiveness is often poorly studied. Here, using twelve years’ census data collected from 78 wetlands in the Yangtze River floodplain, we aimed to understand the effect of these variables on five Anatidae species, and evaluate the effectiveness of the conservation measures by comparing population trends of these species among wetlands that differ in conservations status. We showed that the slope angle of a wetland and the variation thereof best explain the differences in densities of four species. We also found that the population abundances of the Anatidae species generally declined in wetlands along the Yangtze River floodplain over time, with a steeper decline in wetlands with a lower protection status, indicating that current conservation policies might deliver benefits for wintering Anatidae species in China, as population sizes of the species were buffered to some extent against decline in numbers in wetlands with a higher level protection status. We recommend several protection measures to stop the decline of these Anatidae species in wetlands along the Yangtze River floodplain, which are of great importance for the East Asian-Australasian Flyway.

Effect of conservation efforts and ecological variables on waterbird population sizes in wetlands of the Yangtze River.

PubMed

Zhang, Yong; Jia, Qiang; Prins, Herbert H T; Cao, Lei; de Boer, Willem Frederik

2015-11-25

Forage quality and availability, climatic factors, and a wetland's conservation status are expected to affect the densities of wetland birds. However, the conservation effectiveness is often poorly studied. Here, using twelve years' census data collected from 78 wetlands in the Yangtze River floodplain, we aimed to understand the effect of these variables on five Anatidae species, and evaluate the effectiveness of the conservation measures by comparing population trends of these species among wetlands that differ in conservations status. We showed that the slope angle of a wetland and the variation thereof best explain the differences in densities of four species. We also found that the population abundances of the Anatidae species generally declined in wetlands along the Yangtze River floodplain over time, with a steeper decline in wetlands with a lower protection status, indicating that current conservation policies might deliver benefits for wintering Anatidae species in China, as population sizes of the species were buffered to some extent against decline in numbers in wetlands with a higher level protection status. We recommend several protection measures to stop the decline of these Anatidae species in wetlands along the Yangtze River floodplain, which are of great importance for the East Asian-Australasian Flyway.

27 CFR 9.66 - Russian River Valley.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

27 CFR 9.66 - Russian River Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

27 CFR 9.66 - Russian River Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

27 CFR 9.66 - Russian River Valley.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

27 CFR 9.66 - Russian River Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

[Temporal and spatial distribution of red tide in Yangtze River Estuary and adjacent waters].

PubMed

Liu, Lu-San; Li, Zi-Cheng; Zhou, Juan; Zheng, Bing-Hui; Tang, Jing-Liang

2011-09-01

The events of red tide were collected in Yangtze River Estuary and adjacent waters from 1972 to 2009. Based on geographic information system (GIS) analysis on the temporal and spatial distribution of red tide, the distribution map was generated accordingly. The results show: (1) There are three red tide-prone areas, which are outside the Yangtze River estuary and the eastern of Sheshan, Huaniaoshan-Shengshan-Gouqi, Zhoushan and the eastern of Zhujiajian. The red tide occurred 174 times in total, in which there were 25 times covered the area was larger than 1 000 km2. After 2000, the frequency of red tide were significantly increasing; (2) The frequent occurrence of red tide was in May (51% of total occurrence) and June (20% of total occurrence); (3) In all of the red tide plankton, the dominant species were Prorocentrum danghaiense, Skeletonema costatum, Prorocentrum dantatum, Nactiluca scientillans. The red tides caused by these species were 38, 35, 15, 10 times separately.

Direct Detection of Potential Pyrethroids in Yangtze River via an Imprinted Multilayer Phosphorescence Probe.

PubMed

Chen, Li; Lv, Xiaodong; Dai, Jiangdong; Sun, Lin; Huo, Pengwei; Li, Chunxiang; Yan, Yongsheng

2018-01-01

A novel tailored multilayer probe for monitoring potential pyrethroids in the Yangtze River was proposed. The room-temperature phosphorescence method was applied to realize a detection strategy that is superior to the fluorescence method. Efficient Mn-doped ZnS quantum dots with uniform size of 4.6 nm were firstly coated with a mesoporous silica to obtain a suitable intermediate transition layer, then an imprinted layer containing bifenthrin specific recognition sites was anchored. Characterizations verified the multilayer structure convincingly and the detection process relied on the electron transfer-induced fluorescence quenching mechanism. Optional detection time and standard detection curve were obtained within a concentration range from 5.0 to 50 μmol L -1 . The stability was verified to be good after 12 replicates. Feasibility of the probe was proved by monitoring water samples from the Zhenjiang reach of the Yangtze River. The probe offers promise for direct bifenthrin detection in unknown environmental water with an accurate and stable phosphorescence analysis strategy.

4. SNAKE RIVER VALLEY IRRIGATION DISTRICT, PHOTOGRAPHIC COPY OF DRAWING, ...

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

4. SNAKE RIVER VALLEY IRRIGATION DISTRICT, PHOTOGRAPHIC COPY OF DRAWING, PROPOSED SECTION OF DIVERSION DAM ACROSS SNAKE RIVER, SHEET 1 OF 5, 1924 (on file at the Idaho State Office of Water Resources, Boise, Idaho) - Snake River Valley Irrigation District, East Side of Snake River (River Mile 796), Shelley, Bingham County, ID

2. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, PHOTOGRAPHIC COPY OF ...

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

2. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, PHOTOGRAPHIC COPY OF DRAWING, PLAN, SHEET 5 OF 5, 1924 (on file at the Idaho State Office of Water Resources, Boise, Idaho) - Snake River Valley Irrigation District, East Side of Snake River (River Mile 796), Shelley, Bingham County, ID

3. SNAKE RIVER VALLEY IRRIGATION DISTRICT, PHOTOGRAPHIC COPY OF DRAWING, ...

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

3. SNAKE RIVER VALLEY IRRIGATION DISTRICT, PHOTOGRAPHIC COPY OF DRAWING, PROFILE AND ALIGNMENT OF DAM ACROSS WEST CHANNEL OF SNAKE RIVER, SHEET 3 OF 5, 1924 (on file at the Idaho State Office of Water Resources, Boise, Idaho) - Snake River Valley Irrigation District, East Side of Snake River (River Mile 796), Shelley, Bingham County, ID

Identification of long-term trends and seasonality in high-frequency water quality data from the Yangtze River basin, China

PubMed Central

He, Bin; Chen, Yaning; Zou, Shan; Wang, Yi; Nover, Daniel; Chen, Wen; Yang, Guishan

2018-01-01

Comprehensive understanding of the long-term trends and seasonality of water quality is important for controlling water pollution. This study focuses on spatio-temporal distributions, long-term trends, and seasonality of water quality in the Yangtze River basin using a combination of the seasonal Mann-Kendall test and time-series decomposition. The used weekly water quality data were from 17 environmental stations for the period January 2004 to December 2015. Results show gradual improvement in water quality during this period in the Yangtze River basin and greater improvement in the Uppermost Yangtze River basin. The larger cities, with high GDP and population density, experienced relatively higher pollution levels due to discharge of industrial and household wastewater. There are higher pollution levels in Xiang and Gan River basins, as indicated by higher NH4-N and CODMn concentrations measured at the stations within these basins. Significant trends in water quality were identified for the 2004–2015 period. Operations of the three Gorges Reservoir (TGR) enhanced pH fluctuations and possibly attenuated CODMn, and NH4-N transportation. Finally, seasonal cycles of varying strength were detected for time-series of pollutants in river discharge. Seasonal patterns in pH indicate that maxima appear in winter, and minima in summer, with the opposite true for CODMn. Accurate understanding of long-term trends and seasonality are necessary goals of water quality monitoring system efforts and the analysis methods described here provide essential information for effectively controlling water pollution. PMID:29466354

Identification of long-term trends and seasonality in high-frequency water quality data from the Yangtze River basin, China.

PubMed

Duan, Weili; He, Bin; Chen, Yaning; Zou, Shan; Wang, Yi; Nover, Daniel; Chen, Wen; Yang, Guishan

2018-01-01

Comprehensive understanding of the long-term trends and seasonality of water quality is important for controlling water pollution. This study focuses on spatio-temporal distributions, long-term trends, and seasonality of water quality in the Yangtze River basin using a combination of the seasonal Mann-Kendall test and time-series decomposition. The used weekly water quality data were from 17 environmental stations for the period January 2004 to December 2015. Results show gradual improvement in water quality during this period in the Yangtze River basin and greater improvement in the Uppermost Yangtze River basin. The larger cities, with high GDP and population density, experienced relatively higher pollution levels due to discharge of industrial and household wastewater. There are higher pollution levels in Xiang and Gan River basins, as indicated by higher NH4-N and CODMn concentrations measured at the stations within these basins. Significant trends in water quality were identified for the 2004-2015 period. Operations of the three Gorges Reservoir (TGR) enhanced pH fluctuations and possibly attenuated CODMn, and NH4-N transportation. Finally, seasonal cycles of varying strength were detected for time-series of pollutants in river discharge. Seasonal patterns in pH indicate that maxima appear in winter, and minima in summer, with the opposite true for CODMn. Accurate understanding of long-term trends and seasonality are necessary goals of water quality monitoring system efforts and the analysis methods described here provide essential information for effectively controlling water pollution.

Groundwater quality in the Santa Clara River Valley, California

USGS Publications Warehouse

Burton, Carmen A.; Landon, Matthew K.; Belitz, Kenneth

2011-01-01

The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Valley, Las Posas Valley, and Simi Valley (California Department of Water Resources, 2003; Montrella and Belitz, 2009). The SCRV study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 12 to 28 inches. The study unit is drained by the Ventura and Santa Clara Rivers, and Calleguas Creek. The primary aquifer system in the Ventura River Valley, Ojai Valley, Upper Ojai Valley, and Simi Valley basins is largely unconfined alluvium. The primary aquifer system in the remaining groundwater basins mainly consists of unconfined sands and gravels in the upper portion and partially confined marine and nonmarine deposits in the lower portion. The primary aquifer system in the SCRV study unit is defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are completed in the primary aquifer system to depths of 200 to 1,100 feet below land surface (bls). The wells contain solid casing reaching from the land surface to a depth of about 60-700 feet, and are perforated below the solid casing to allow water into the well. Water quality in the primary aquifer system may differ from the water in the shallower and deeper parts of the aquifer. Land use in the study unit is approximately 40 percent (%) natural (primarily shrubs, grassland, and wetlands), 37% agricultural, and 23% urban. The primary crops are citrus, avocados, alfalfa, pasture, strawberries, and dry beans. The largest urban areas in the study unit are the cities of

[Distribution and source of particulate organic carbon and particulate nitrogen in the Yangtze River Estuary in summer 2012].

PubMed

Xing, Jian-Wei; Xian, Wei-Wei; Sheng, Xiu-Zhen

2014-07-01

Based on the data from the cruise carried out in August 2012 in the Yangtze River Estuary and its adjacent waters, spatial distributions of particulate organic carbon (POC), particulate nitrogen (PN) and their relationships with environmental factors were studied, and the source of POC and the contribution of phytoplankton to POC were analyzed combined with n (C)/n (N) ratio and chlorophyll a (Chl a) in the Yangtze River Estuary in summer 2012. The results showed that the concentrations of POC in the Yangtze River Estuary ranged from 0.68 mg x L(-1) to 34.80 mg x L(-1) in summer and the average content was 3.74 mg x L(-1), and PN contents varied between 0.03 mg x L(-1) and 9.13 mg x L(-1) with an average value of 0.57 mg x L(-1). Both of them presented that the concentrations in bottom layers were higher than those in the surface. POC and PN as well as total suspended matter (TSM) showed a extremel similar horizontal distribution trend that the highest values appeared in the near of the mouth and southwest of the survey waters, and decreased rapidly as toward the open seas, both of them showed higher contents in coastal zones and lower in outer sea. There was a fairly good positive linear relationship between POC and PN, which indicated that they had the same source. POC and PN expressed significantly positive correlations with TSM and chemical oxygen demand (COD), but showed relatively weak correlations with salinit and chlorophyll a, which demonstrated that terrestrial inputs had a strong influence on the distribution of POC and PN, and phytoplankton production was not the major source of organic matters in the Yangtze River Estuary. Both the n (C)/n (N) ratio and POC/Chl a analysis showed that the main source of POC was terrestrial inputs, and organic debris was the main existence form of POC. Quantitative analysis showed the biomass of phytoplankton only made an average of 2.54% contribution to POC in the Yangtze Rive Estuary in summer and non-living POC

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in sediments from the Yellow and Yangtze Rivers, China.

PubMed

Gao, Lirong; Huang, Huiting; Liu, Lidan; Li, Cheng; Zhou, Xin; Xia, Dan

2015-12-01

Polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are toxic environmental pollutants that are often found in sediments. The Yangtze and Yellow rivers in China are two of the largest rivers in Asia and are therefore important aquatic ecosystems; however, few studies have investigated the PCDD/F and PCB content in the sediments of these rivers. Accordingly, this study was conducted to generate baseline data for future environmental risk assessments. In the present study, 26 surface sediments from the middle reaches of the Yellow and Yangtze rivers were analyzed for PCDD/Fs and dioxin-like (dl) PCBs by high-resolution gas chromatography and high-resolution mass spectrometry. The ranges of PCDD/F, dl-PCB, and WHO-TEQ content in sediments from the Yellow River were 2.1-19.8, 1.11-9.9, and 0.08-0.57 pg/g (dry weight), respectively. The ranges of PCDD/F, dl-PCB, and WHO-TEQ content in sediments from the Yangtze River were 6.1-84.9, 1.8-24.1, and 0.13-0.29 pg/g (dry weight), respectively. Total organic carbon and dl-PCB contents in the Yellow River were significantly correlated (Spearman's correlation coefficient, r = 0.64, P < 0.05). It is well known that total organic carbon plays a role in the transport and redistribution of dl-PCB. Principal component analysis indicated that PCDD/Fs may arise from pentachlorophenol, sodium pentachlorophenate, and atmospheric deposition, while dl-PCBs likely originate from burning of coal and wood for domestic heating. The dioxin levels in the river sediments examined in this study were relatively low. These findings advance our knowledge regarding eco-toxicity and provide useful information regarding contamination sources.

27 CFR 9.78 - Ohio River Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Valley.” (b) Approved maps. The approved maps for determining the boundary of the Ohio River Valley... boundary proceeds in a straight line westerly to the town of Dry Ridge in Grant County, Kentucky...

Human impacts on sediment in the Yangtze River: A review and new perspectives

NASA Astrophysics Data System (ADS)

Yang, H. F.; Yang, S. L.; Xu, K. H.; Milliman, J. D.; Wang, H.; Yang, Z.; Chen, Z.; Zhang, C. Y.

2018-03-01

Changes in riverine suspended and riverbed sediments have environmental, ecological and social implications. Here, we provide a holistic review of water and sediment transport and examine the human impacts on the flux, concentration and size of sediment in the Yangtze River in recent decades. We find that most of the fluvial sediment has been trapped in reservoirs, except for the finest portion. Furthermore, soil-conservation since the 1990s has reduced sediment yield. From 1956-1968 (pre-dam period) to 2013-2015 (post-dams and soil-conservation), the sediment discharge from the sub-basins decreased by 91%; in the main river, the sediment flux decreased by 99% at Xiangjiaba (upper reach), 97% at Yichang (transition between upper and middle reaches), 83% at Hankou (middle reach), and 77% at Datong (tidal limit). Because the water discharge was minimally impacted, the suspended sediment concentration decreased to the same extent as the sediment flux. Active erosion of the riverbed and coarsening of surficial sediments were observed in the middle and lower reaches. Fining of suspended sediments was identified along the river, which was counteracted by downstream erosion. Along the 700-km-long Three Gorges Reservoir, which retained 80% of the sediment from upstream, the riverbed gravel or rock was buried by mud because of sedimentation after impoundment. Along with these temporal variations, the striking spatial patterns of riverine suspended and riverbed sediments that were previously exhibited in this large basin were destroyed or reversed. Therefore, we conclude that the human impacts on sediment in the Yangtze River are strong and systematic.

Predicting assemblages and species richness of endemic fish in the upper Yangtze River.

PubMed

He, Yongfeng; Wang, Jianwei; Lek-Ang, Sithan; Lek, Sovan

2010-09-01

The present work describes the ability of two modeling methods, Classification and Regression Tree (CART) and Random Forest (RF), to predict endemic fish assemblages and species richness in the upper Yangtze River, and then to identify the determinant environmental factors contributing to the models. The models included 24 predictor variables and 2 response variables (fish assemblage and species richness) for a total of 46 site units. The predictive quality of the modeling approaches was judged with a leave-one-out validation procedure. There was an average success of 60.9% and 71.7% to assign each site unit to the correct assemblage of fish, and 73% and 84% to explain the variance in species richness, by using CART and RF models, respectively. RF proved to be better than CART in terms of accuracy and efficiency in ecological applications. In any case, the mixed models including both land cover and river characteristic variables were more powerful than either individual one in explaining the endemic fish distribution pattern in the upper Yangtze River. For instance, altitude, slope, length, discharge, runoff, farmland and alpine and sub-alpine meadow played important roles in driving the observed endemic fish assemblage structure, while farmland, slope grassland, discharge, runoff, altitude and drainage area in explaining the observed patterns of endemic species richness. Therefore, the various effects of human activity on natural aquatic ecosystems, in particular, the flow modification of the river and the land use changes may have a considerable effect on the endemic fish distribution patterns on a regional scale. Copyright 2010 Elsevier B.V. All rights reserved.

Trends and variability of daily precipitation extremes during 1960-2012 in the Yangtze River Basin, China

USDA-ARS?s Scientific Manuscript database

Trends and variability of extreme precipitation events are important for water-related disaster prevention and mitigation as well as water resource management. Based on daily precipitation dataset from 143 meteorological stations in the Yangtze River Basin (YRB), a suite of precipitation indices rec...

Linkages between the spatial toxicity of sediments and sediment dynamics in the Yangtze River Estuary and neighboring East China Sea.

PubMed

Gao, Jinjuan; Shi, Huahong; Dai, Zhijun; Mei, Xuefei; Zong, Haibo; Yang, Hongwei; Hu, Lingling; Li, Shushi

2018-02-01

Anthropogenic activities are driving an increase in sediment contamination in coastal areas. This poses significant challenges for the management of estuarine ecosystems and their adjacent seas worldwide. However, few studies have been conducted on how dynamic mechanisms affect the sediment toxicity in the estuarine environment. This study was designed to investigate the linkages between sediment toxicity and hydrodynamics in the Yangtze River Estuary (YRE) area. High sediment toxicity was found in the Yangtze River mouth (Region I), the depocenter of the Yangtze River Delta (Region II), and the southeastern area of the adjacent sea (Region III), while low sediment toxicity was found in the northeastern offshore region (Region IV). A spatial comparison analysis and regression model indicated that the distributed pattern of sediment toxicity was likely related to hydrodynamics and circumfluence in the East China Sea (ECS) shelf. Specifically, high sediment toxicity in Region I may be affected by the Yangtze River Pump (YRP) and the low hydrodynamics there, and high toxicity in Region II can be influenced by the low sediment dynamics and fine sediment in the depocenter. The high sediment toxicity in Region III might be related to the combination of the YRP and Taiwan Warm Current, while the low toxicity in Region IV may be influenced by the local coarse-grained relict sand with strong sediment dynamics there. The present research results further suggest that it is necessary to link hydrodynamics and the spatial behavior of sediment and sediment-derived pollutants when assessing the pollution status of estuarine environments, especially for those mega-estuaries and their neighboring ocean environments with complex waves, tides and ocean currents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling the spatial-temporal dynamics of net primary production in Yangtze River Basin using IBIS model

USGS Publications Warehouse

Zhang, Z.; Jiang, H.; Liu, J.; Zhu, Q.; Wei, X.; Jiang, Z.; Zhou, G.; Zhang, X.; Han, J.

2011-01-01

The climate change has significantly affected the carbon cycling in Yangtze River Basin. To better understand the alternation pattern for the relationship between carbon cycling and climate change, the net primary production (NPP) were simulated in the study area from 1956 to 2006 by using the Integrated Biosphere Simulator (IBIS). The results showed that the average annual NPP per square meter was about 0.518 kg C in Yangtze River Basin. The high NPP levels were mainly distributed in the southeast area of Sichuan, and the highest value reached 1.05 kg C/m2. The NPP increased based on the simulated temporal trends. The spatiotemporal variability of the NPP in the vegetation types was obvious, and it was depended on the climate and soil condition. We found the drought climate was one of critical factor that impacts the alterations of the NPP in the area by the simulation. ?? 2011 IEEE.

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

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

Capacity of humic substances to complex with iron at different salinities in the Yangtze River estuary and East China Sea.

PubMed

Yang, Rujun; Su, Han; Qu, Shenglu; Wang, Xuchen

2017-05-03

The iron binding capacities (IBC) of fulvic acid (FA) and humic acid (HA) were determined in the salinity range from 5 to 40. The results indicated that IBC decreased while salinity increased. In addition, dissolved iron (dFe), FA and HA were also determined along the Yangtze River estuary's increasing salinity gradient from 0.14 to 33. The loss rates of dFe, FA and HA in the Yangtze River estuary were up to 96%, 74%, and 67%, respectively. The decreases in dFe, FA and HA, as well as the change in IBC of humic substances (HS) along the salinity gradient in the Yangtze River estuary were all well described by a first-order exponential attenuation model: y(dFe/FA/HA, S) = a 0 × exp(kS) + y 0 . These results indicate that flocculation of FA and HA along the salinity gradient resulted in removal of dFe. Furthermore, the exponential attenuation model described in this paper can be applied in the major estuaries of the world where most of the removal of dFe and HS occurs where freshwater and seawater mix.

Variation of River Islands around a Large City along the Yangtze River from Satellite Remote Sensing Images

PubMed Central

Shi, Haiyun; Gao, Chao; Dong, Changming; Xia, Changshui; Xu, Guanglai

2017-01-01

River islands are sandbars formed by scouring and silting. Their evolution is affected by several factors, among which are runoff and sediment discharge. The spatial-temporal evolution of seven river islands in the Nanjing Section of the Yangtze River of China was examined using TM (Thematic Mapper) and ETM (Enhanced Thematic Mapper)+ images from 1985 to 2015 at five year intervals. The following approaches were applied in this study: the threshold value method, binarization model, image registration, image cropping, convolution and cluster analysis. Annual runoff and sediment discharge data as measured at the Datong hydrological station upstream of Nanjing section were also used to determine the roles and impacts of various factors. The results indicated that: (1) TM/ETM+ images met the criteria of information extraction of river islands; (2) generally, the total area of these islands in this section and their changing rate decreased over time; (3) sediment and river discharge were the most significant factors in island evolution. They directly affect river islands through silting or erosion. Additionally, anthropocentric influences could play increasingly important roles. PMID:28953218

Rhenium Concentration Variations in the Non-flood Period of the Yangtze River Water and Estimation of the Oxidation Rate of Organic Carbon

NASA Astrophysics Data System (ADS)

Xu, P.; Chen, Y.; Li, S.; Wang, K.

2017-12-01

In geological history, the uplift of the Tibet plateau has accelerated the silicate weathering and organic carbon burial at the same time, which made great influence on the global carbon cycle by increasing the carbon sink. Because of the vital connection between tectonic uplift and carbon cycle, more and more attention was casted on rivers originating from orogens. The Yangtze River, as an important large river in the world, is one of them. However, although silicate weathering has been studied thoroughly, researches on organic carbon cycle are much less, and oxidation of fossil organic carbon remained poorly constrained. In this study, we try to use rhenium(Re) as a proxy to estimate the oxidation rate of fossil organic carbon and thus proceed our understanding towards the carbon cycle, the silicate weathering. This is because Re has a close relationship with organic carbon in the sediments and will be released into hydrological network in the mountain river catchments by being oxidized and exist as soluble ReO4-, so that we can use Re concentration in river water to estimate the oxidation rate of organic carbon. We collected water samples from the Yangtze River fortnightly at Banqiao Ferry and the sampling date cover the non-flood period. In this way, we are able to have a rough estimate of the amount of carbon dioxide that released to the atmosphere by the oxidation of organic carbon, using the data of non-flood period we got. We found that Re concentration in Yangtze River ranges approximately from 45 to 85 pmol/L. The rate of organic carbon weathering is estimated using the expression, ΦCO2,fossil=[Re]×runoff×[OC/Re]rock, and according to researches on the black shale of Yangtze River, the value 2.86×106 is chosen as the ratio OC(organic carbon) to Re in the black shale. The result is a really high flux, up to 152×109mol/y, just a little less than of the CO2 consumption rates from silicate weathering which is 191×109mol/y and about 166×109mol/y in non

Predictability and Prediction of Low-Frequency Rainfall Over the Lower Reaches of the Yangtze River Valley on the Time Scale of 20 to 30 days

NASA Astrophysics Data System (ADS)

Yang, Qiuming

2018-01-01

This paper presents a predictability study of the 20-30-day low-frequency rainfall over the lower reaches of the Yangtze River valley (LYRV). This study relies on an extended complex autoregressive (ECAR) model method, which is based on the principal components of the global 850 hPa low-frequency meridional wind. ECAR is a recently advanced climate forecast method, based on data-driven models. It not only reflects the lagged variations information between the leading low-frequency components of the global circulation and rainfall in a complex space, but also displays the ability to describe the synergy variations of low-frequency components of a climate system in a low dimensional space. A 6-year forecast experiment is conducted on the low-frequency rainfall over the LYRV for the extended-range daily forecasts during 2009-2014, based on the time-varying high-order ECAR. These experimental results demonstrate that the useful skills of the real-time forecasts are achieved for an extended lead-time up to 28 days with a fifth-order model, and are also shown to be 27-day lead for forecasts which are initiated from weak intraseasonal oscillation (ISO). This high-order ECAR displays the ability to significantly improve the predictions of the ISO. The analysis of the 20-30-day ISO predictability reveals a predictability limit of about 28-40 days. Therefore, the forecast framework used in this study is determined to have the potential to assist in improving the real-time forecasts for the 20-30-day oscillations related to the heavy rainfall over the LYRV in summer.

Genetic diversity of the Chinese goat in the littoral zone of the Yangtze River as assessed by microsatellite and mtDNA.

PubMed

E, Guang-Xin; Zhao, Yong-Ju; Chen, Li-Peng; Ma, Yue-Hui; Chu, Ming-Xing; Li, Xiang-Long; Hong, Qiong-Hua; Li, Lan-Hui; Guo, Ji-Jun; Zhu, Lan; Han, Yan-Guo; Gao, Hui-Jiang; Zhang, Jia-Hua; Jiang, Huai-Zhi; Jiang, Cao-De; Wang, Gao-Fu; Ren, Hang-Xing; Jin, Mei-Lan; Sun, Yuan-Zhi; Zhou, Peng; Huang, Yong-Fu

2018-05-01

The objective of this study was to assess the genetic diversity and population structure of goats in the Yangtze River region using microsatellite and mtDNA to better understand the current status of those goat genetic diversity and the effects of natural landscape in fashion of domestic animal genetic diversity. The genetic variability of 16 goat populations in the littoral zone of the Yangtze River was estimated using 21 autosomal microsatellites, which revealed high diversity and genetic population clustering with a dispersed geographical distribution. A phylogenetic analysis of the mitochondrial D-loop region (482 bp) was conducted in 494 goats from the Yangtze River region. In total, 117 SNPs were reconstructed, and 173 haplotypes were identified, 94.5% of which belonged to lineages A and B. Lineages C, D, and G had lower frequencies (5.2%), and lineage F haplotypes were undetected. Several high-frequency haplotypes were shared by different ecogeographically distributed populations, and the close phylogenetic relationships among certain low-frequency haplotypes indicated the historical exchange of genetic material among these populations. In particular, the lineage G haplotype suggests that some west Asian goat genetic material may have been transferred to China via Muslim migration.

Urban Household Carbon Emission and Contributing Factors in the Yangtze River Delta, China

PubMed Central

Xu, Xibao; Tan, Yan; Chen, Shuang; Yang, Guishan; Su, Weizhong

2015-01-01

Carbon reduction at the household level is an integral part of carbon mitigation. This study analyses the characteristics, effects, contributing factors and policies for urban household carbon emissions in the Yangtze River Delta of China. Primary data was collected through structured questionnaire surveys in three cities in the region – Nanjing, Ningbo, and Changzhou in 2011. The survey data was first used to estimate the magnitude of household carbon emissions in different urban contexts. It then examined how, and to what extent, each set of demographic, economic, behavioral/cognitive and spatial factors influence carbon emissions at the household level. The average of urban household carbon emissions in the region was estimated to be 5.96 tonnes CO2 in 2010. Energy consumption, daily commuting, garbage disposal and long-distance travel accounted for 51.2%, 21.3%, 16.0% and 11.5% of the total emission, respectively. Regulating rapidly growing car-holdings of urban households, stabilizing population growth, and transiting residents’ low-carbon awareness to household behavior in energy saving and other spheres of consumption in the context of rapid population aging and the growing middle income class are suggested as critical measures for carbon mitigation among urban households in the Yangtze River Delta. PMID:25884853

Modal analysis of annual runoff volume and sediment load in the Yangtze river-lake system for the period 1956-2013.

PubMed

Chen, Huai; Zhu, Lijun; Wang, Jianzhong; Fan, Hongxia; Wang, Zhihuan

2017-07-01

This study focuses on detecting trends in annual runoff volume and sediment load in the Yangtze river-lake system. Times series of annual runoff volume and sediment load at 19 hydrological gauging stations for the period 1956-2013 were collected. Based on the Mann-Kendall test at the 1% significance level, annual sediment loads in the Yangtze River, the Dongting Lake and the Poyang Lake were detected with significantly descending trends. The power spectrum estimation indicated predominant oscillations with periods of 8 and 20 years are embedded in the runoff volume series, probably related to the El Niño Southern Oscillation (2-7 years) and Pacific Decadal Oscillation (20-30 years). Based on dominant components (capturing more than roughly 90% total energy) extracted by the proper orthogonal decomposition method, total change ratios of runoff volume and sediment load during the last 58 years were evaluated. For sediment load, the mean CRT value in the Yangtze River is about -65%, and those in the Dongting Lake and the Poyang Lake are -92.2% and -87.9% respectively. Particularly, the CRT value of the sediment load in the channel inflow of the Dongting Lake is even -99.7%. The Three Gorges Dam has intercepted a large amount of sediment load and decreased the sediment load downstream.

Characterizing hydrological activities over Yangtze River basin using the new HUST-Grace2016 model, MODIS, and NCEP/NCAR data

NASA Astrophysics Data System (ADS)

Zhou, H.; Luo, Z.; Tangdamrongsub, N.; He, L.

2017-12-01

Accurate TWS estimation is important to evaluate the situation of the water resource over the Yangtze River basin. This study exploits the TWS observation from the new gravity model, HUST-Grace06, which is developed by a new low-frequency noise processing strategy. A novel GRACE post-processing approach is proposed to enhance the quality of the TWS estimate, and the improved TWS is used to characterize the hydrological activities over the Yangtze River basin. The approach includes the effective noise reduction and the leakage error mitigation based on forward modeling. The HUST-Grace06 derived TWS presents good agreement with the CSR mascon solution as well as the PCR-GLOBWB hydrological model. Particularly, our solution provides remarkable performance in identifying the extreme climate events e.g., flood and drought over the Yangtze River basin. In addition, for the first time, the NCEP/NCAR reanalysis data is incorporated with GRACE in the exploration of the climate induced hydrological activities. The comparison between GRACE and the MODIS-derived NDVI data is also conducted to investigate their connection regarding temporal and spatial distribution. The analysis suggests that the terrestrial reflectance data can be used to represent the TWS information. Importantly, such information can be used to fill the missing data in case of the early termination of GRACE or during the prelaunch of the GRACE Follow-On mission.

Towards Biological Restoration of Tehran Megalopolis River Valleys- Case Study: Farahzad River

NASA Astrophysics Data System (ADS)

Samadi, Nafishe; Oveis Torabi, Seyed; Akhani, Hossein

2017-04-01

Towards biological restoration of Tehran megalopolis river-valleys: case study Farahzad river 1Nafiseh Samadi, 2OveisTorabi, 3Hossein Akhani 1Mahsab Shargh Company, Tehran ,Iran, nafiseh19@gmail.com 2 Mahsab Shargh Company, Tehran ,Iran, weg@tna-co.com 3Department of Plant Sciences, Halophytes and C4 Research Laboratory, School of Biology, College of Sciences, University of Tehran, PO Box 14155-6455, Tehran, Iran, akhani@khayam.ut.ac.ir Tehran is located in northcentral parts of Iran on the alluvium of southern Alborz Mountains. Seven rivers originated from the highlands of N Tehran run inside and around the city. Many of these river valleys have been deformed by a variety of urban utilizations such as garden, building, canal, park, autobahn etc. Tehran with more than eight million populations suffered from adverse environmental conditions such as pollution and scarcity of natural habitats for recreational activities. Ecological restoration of altered river valleys of Tehran is one of the priorities of Tehran municipality started as a pilot project in Farahzad river. Intensive disturbance, conversion into various urban utilization, illegal building construction, waste water release into the river, garbage accumulation, artificial park constructions and domination of invasive species have largely altered the river. Parts of the river located in Pardisan Nature Park was studied before its complete deformation into a modern park. The riparian vegetation consisted of Tamarix ramosissima and Salix acmophylla shrubs with large number of aquatic and palustric plants. The norther parts of the river still contain semi-natural vegetation which change into patchy and intensive degraded habitats towards its southern parts. In northern parts of valley there are old gardens of Morus alba and Juglans regia, and planted trees such as Plataneus oreientalis and Acer negundo. Salix acmophylla, Fraxinus excelsior and Celtis caucasica are native species growing on river margin or

Will river erosion below the Three Gorges Dam stop in the middle Yangtze?

NASA Astrophysics Data System (ADS)

Lai, X.; Yin, D.; Finlayson, B. L.; Wei, T.; Li, M.; Yuan, W.; Yang, S.; Dai, Z.; Gao, S.; Chen, Z.

2017-11-01

The environmental impact of the Three Gorges Dam has been a subject of vigorous academic, political and social debate since its inception. This includes the key issue of post-dam river channel erosion, which was predicted by the feasibility study to extend to the river mouth. In this paper we examine the geomorphic response of the channel of the middle Yangtze for 660 km downstream of the dam. Using data on channel characteristics, bed material and sediment transport, we show that in the decade following the dam closure, pre-dam seasonal erosion has been replaced by year-round erosion, a pattern most marked at the upstream end of the study area. The sediment carrying capacity of the river channel has been largely reduced below the dam. The locus of bed scour has moved progressively downstream, ceasing as the bed material became too coarse to be transported (e.g. D50: 0.29 mm pre-dam coarsened to 20 mm below the dam by 2008). About 400 km below the dam there is a reduction in channel slope that changes the sediment carrying capacity from 0.25 kg m-3 to only about 0.05 kg m-3, which is insufficient to move bed sediment. The new long-term hydro-morphological equilibrium that will be established in this section of the middle Yangtze will prevent the further incision downstream initiated by the Three Gorges Dam. The results suggest that the full extent of adverse environmental impact predicted by the pre-dam studies will not eventuate.

The asymmetric response of Yangtze river basin summer rainfall to El Niño/La Niña

NASA Astrophysics Data System (ADS)

Hardiman, Steven C.; Dunstone, Nick J.; Scaife, Adam A.; Bett, Philip E.; Li, Chaofan; Lu, Bo; Ren, Hong-Li; Smith, Doug M.; Stephan, Claudia C.

2018-02-01

The Yangtze river basin, in South East China, experiences anomalously high precipitation in summers following El Niño. This can lead to extensive flooding and loss of life. However, the response following La Niña has not been well documented. In this study, the response of Yangtze summer rainfall to El Niño/La Niña is found to be asymmetric, with no significant response following La Niña. The nature of this asymmetric response is found to be in good agreement with that simulated by the Met Office seasonal forecast system. Yangtze summer rainfall correlates positively with spring sea surface temperatures in the Indian Ocean and northwest Pacific. Indian Ocean sea surface temperatures are found to respond linearly to El Niño/La Niña, and to have a linear impact on Yangtze summer rainfall. However, northwest Pacific sea surface temperatures respond much more strongly following El Niño and, further, correlate more strongly with positive rainfall years. It is concluded that, whilst delayed Indian Ocean signals may influence summer Yangtze rainfall, it is likely that they do not lead to the asymmetric nature of the rainfall response to El Niño/La Niña.

[Challenges and countermeasures of forestry schistosomiasis control programs in ecological priority of Yangtze River economic belt development].

PubMed

Ning, Su; Yong-Jie, Xu

2016-12-13

Relevant projects carried out within the Yangtze River economic belt on the impact of schistosomiasis epidemic and transmission are important issues for "ecological priority" in the process of implementing the strategy. The key problems of schistosomiasis epidemic risk, epidemic happening repeatedly, difficulty of rehabilitating Oncomelania hupensis snail control and schistosomiasis prevention forest, lag of evaluation system and platform construction, lack of basic research, et al. were analyzed in the Yangtze River economic belt taking "ecological priority" as the basis in this paper. Then corresponding countermeasures to these challenges were put forward so as to provide the reference for the national forestry schistosomiasis control programs, which include: execution of the comprehensive prevention and control strategy, scheming of the new round of forestry schistosomiasis control programs, strengthening schistosomiasis prevention and control, promoting productivity in existing forestry to consolidate and improve the achievements of previous forestry schistosomiasis control programs, and promoting the intensity of technological innovation to improve the technological level of forestry schistosomiasis control programs.

Pu and 137Cs in the Yangtze River estuary sediments: distribution and source identification.

PubMed

Liu, Zhiyong; Zheng, Jian; Pan, Shaoming; Dong, Wei; Yamada, Masatoshi; Aono, Tatsuo; Guo, Qiuju

2011-03-01

Pu isotopes and (137)Cs were analyzed using sector field ICP-MS and γ spectrometry, respectively, in surface sediment and core sediment samples from the Yangtze River estuary. (239+240)Pu activity and (240)Pu/(239)Pu atom ratios (>0.18) shows a generally increasing trend from land to sea and from north to south in the estuary. This spatial distribution pattern indicates that the Pacific Proving Grounds (PPG) source Pu transported by ocean currents was intensively scavenged into the suspended sediment under favorable conditions, and mixed with riverine sediment as the water circulated in the estuary. This process is the main control for the distribution of Pu in the estuary. Moreover, Pu is also an important indicator for monitoring the changes of environmental radioactivity in the estuary as the river basin is currently the site of extensive human activities and the sea level is rising because of global climate changes. For core sediment samples the maximum peak of (239+240)Pu activity was observed at a depth of 172 cm. The sedimentation rate was estimated on the basis of the Pu maximum deposition peak in 1963-1964 to be 4.1 cm/a. The contributions of the PPG close-in fallout Pu (44%) and the riverine Pu (45%) in Yangtze River estuary sediments are equally important for the total Pu deposition in the estuary, which challenges the current hypothesis that the riverine Pu input was the major source of Pu budget in this area.

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

PubMed

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

2018-05-09

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

Study on the Evaluation of Economic Support Index for Pig Breeding in Water Network Area of Middle Reaches of Yangtze River

NASA Astrophysics Data System (ADS)

Leng, Bi-Bin; Zhang, Qi-zhen; Lai, Wen-wei; Tang, Xin-Fan

2018-06-01

The central region of China boasts a long history, abundant resources, convenient transportation, advanced economy, a strong industrial and agricultural foundation and a rapid development of modern service industry, with about 10.7% of the country's total land area, 26.5% of the country's population and a GDP of about 21.4% of the country's total . As the population center, transportation hub, economic hinterland and important market, it is the second echelon of China's economic development; the central region of China plays an important role in the division of labor in China. The middle reaches of the Yangtze River water network includes four neighboring provinces- Hubei, Hunan, Anhui and Jiangxi. Although all four provinces are located in the middle of the Yangtze River Basin, there are still quite some differences. Based on the 2017 Statistical Yearbook data, this paper studies the economic supportive index of pig breeding in four provinces located in the water network area of the middle reaches of the Yangtze River in Jiangxi, Hubei, Hunan and Anhui. The evaluation results show that among the four provinces, the socio-economic conditions of Hubei Province can most support the large-scale cultivation of live pigs, and the support of Jiangxi Province is the weakest.

Debris flow occurrence and sediment persistence, Upper Colorado River Valley, CO

USGS Publications Warehouse

Grimsley, Kyle J; Rathburn, Sara L.; Friedman, Jonathan M.; Mangano, Joseph F.

2016-01-01

Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO

NASA Astrophysics Data System (ADS)

Grimsley, K. J.; Rathburn, S. L.; Friedman, J. M.; Mangano, J. F.

2016-07-01

Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO.

PubMed

Grimsley, K J; Rathburn, S L; Friedman, J M; Mangano, J F

2016-07-01

Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

Sequence stratigraphy of the subaqueous Changjiang (Yangtze River) delta since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Xu, Taoyu; Wang, Guoqing; Shi, Xuefa; Wang, Xin; Yao, Zhengquan; Yang, Gang; Fang, Xisheng; Qiao, Shuqing; Liu, Shengfa; Wang, Xuchen; Zhao, Quanhong

2016-01-01

This study focuses on sedimentary research at the subaqueous Changjiang (Yangtze River) delta, based on five high-resolution seismic profiles and seven borehole cores with accurate AMS 14C datings. Three distinct seismic units were identified from the seismic profiles according to seismic reflection characteristics, and five sedimentary facies were recognized from borehole cores. These facies constituted a fining upward sedimentary sequence in relation to postglacial sea-level transgression. Three sequence surfaces (sequence boundary (SB), transgressive surface (TS), and maximum flooding surface (MFS)) demarcate the boundaries between early transgressive system tract (E-TST), late transgressive system tract (L-TST), early highstand system tract (E-HST) and late highstand system tract (L-HST), which constitute the sixth order sequence. These system tracts were developed coevally with postglacial sea-level rise. E-TST (~ 19-12 ka BP) corresponds to an incised-valley infilling in the early stages of postglacial transgression whereas L-TST (~ 12-7.5 ka BP) was formed during the last stage of postglacial transgression. The progradational structure of L-TST reflected in seismic profiles is possibly related to the intensification of the East Asian summer monsoon. E-HST (~ 7.5-2 ka BP) was deposited in response to the highstand after maximum postglacial transgression was reached, while L-HST (~ 2 ka BP-present) was initiated by accelerated progradation of the Changjiang delta.

Atmospheric deposition and air-sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

NASA Astrophysics Data System (ADS)

Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang

2017-07-01

The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and air-sea gas exchange fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the air-water interface under the influences of river input and atmospheric transport. The air-sea gas exchange of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the air-sea gas exchange reached equilibrium because of low HCH levels in the air and seawater after the long-term banning of HCH and the degradation. The gas exchange flux of HCH was comparable to the dry and wet deposition fluxes at the air-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas exchange flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.

Geology and ground water in Russian River Valley areas and in Round, Laytonville, and Little Lake Valleys, Sonoma and Mendocino Counties, California

USGS Publications Warehouse

Cardwell, G.T.

1965-01-01

This report describes the occurrence, availability, and quality of ground water in seven valley areas along the course of the Russian River in Sonoma and Mendocino Counties, Calif., and in three valleys in the upper drainage reach of the Eel River in Mendocino County. Except for the westward-trending lower Russian River valley, the remaining valley areas along the Russian River (Healdsburg, Alexander, Cloverdale, Sanel, Ukiah, and Potter Valleys) lie in northwest-trending structurally controlled depressions formed in marine rocks of Jurassic and Cretaceous age. The principal aquifer in all the valleys is the alluvium of Recent age, which includes highly permeable channel deposits of gravel and sand. Water for domestic, irrigation, industrial, and other uses is developed by (1) direct diversion from the Russian River and its tributaries, (2) withdrawal of ground water and river water from shallow wells near the river, and (3) withdrawals of ground water from wells in alluvial deposits at varying distances from the river. Surface water in the Russian River and most tributaries is of good chemical quality. The water is a calcium magnesium bicarbonate type and contains 75,200 parts per million of dissolved solids. Ground water is also of good chemical quality throughout most of the drainage basin, but the concentration of dissolved solids (100-300 parts per million) is somewhat higher than that in the surface water. Round, Laytonville, and Little Lake Valleys are in central and northern Mendocino County in the drainage basin of the northwestward flowing Eel River. In Round Valley the alluvium of Recent age yields water of good chemical quality in large quantities. Yields are lower and the chemical quality poorer in Laytonville Valley. Ground water in Little Lake Valley is relatively undeveloped. Selected descriptions of wells, drillers' logs, chemical analyses, and hydrographs showing water-level fluctuations are included in the report. Accompanying maps show the

Formation of A-type granites in the Lower Yangtze River Belt: A perspective from apatite geochemistry

NASA Astrophysics Data System (ADS)

Jiang, Xiao-Yan; Li, He; Ding, Xing; Wu, Kai; Guo, Jia; Liu, Ji-Qiang; Sun, Wei-Dong

2018-04-01

Apatite is ubiquitous in A-type granites, and can be used to elucidate the volatile contents of the silicate melt, which reflect its source characteristics. A-type granites have been recognized as a distinct group of granites. A1- and A2-type subgroups are produced under different extensional settings. However, the details of the mechanisms behind the distinctive geochemical characteristics of A1- and A2-type granites remain obscure. Belts of Cretaceous A1- and A2-type granites occur along the Lower Yangtze River Belt in eastern China. Here we investigated the major and trace element compositions of apatites from contemporary A1- and A2-type granites at different localities along the Lower Yangtze River Belt, in order to decipher their discrepant source processes. Apatites from A1- and A2-type granites show similar major and trace elements, but differ in their F and Cl concentrations. Apatites from A1-type granites in the eastern part of the Lower Yangtze River Belt have much lower F and higher Cl concentrations compared to A2-type granites in the western part. Moreover, from the east to the west, the F concentrations of apatites from A1-type granites increase, while the Cl concentrations decline. In a subducted plate, F is retained by amphibole, chlorite, serpentine and mica minerals through the amphibolite stage, and finally by phengite and lawsonite during the eclogite stage, whereas, Cl is controlled by amphibole, chlorite and serpentine. The high and varied Cl concentrations in A1 subgroup apatites, therefore, may be attributed to the breakdown of amphibole, chlorite and/or serpentine decomposition during partial melting of subducted oceanic crust releasing a large amount of Cl at shallower depth. In contrast, F is transported to deeper depths in the subducted oceanic crust, and released through breakdown of phengite and lawsonite, making an important contribution to the formation of A2-type granites. Apatites from A1- and A2-type granite samples show regular

Shoals and valley plugs in the Hatchie River watershed

USGS Publications Warehouse

Diehl, Timothy H.

2000-01-01

Agricultural land use and gully erosion have historically contributed more sediment to the streams of the Hatchie River watershed than those streams can carry. In 1970, the main sedimentation problem in the watershed occurred in the tributary flood plains. This problem motivated channelization projects (U.S. Department of Agriculture, 1970). By the mid-1980's, concern had shifted to sedimentation in the Hatchie River itself where channelized tributaries were understood to contribute much of the sediment. The Soil Conservation Service [Natural Resources Conservation Service (NRCS) since 1996] estimated that 640,000 tons of bedload (sand) accumulates in the Hatchie River each year and identified roughly the eastern two-thirds of the watershed, where loess is thin or absent, as the main source of sand (U.S. Department of Agriculture, 1986a). The U.S. Geological Survey (USGS), in cooperation with the West Tennessee River Basin Authority (WTRBA), conducted a study of sediment accumulation in the Hatchie River and its tributaries. This report identifies the types of tributaries and evaluates sediment, shoal formation, and valley-plug problems. The results presented here may contribute to a better understanding of similar problems in West Tennessee and the rest of the southeastern coastal plain. This information also will help the WTRBA manage sedimentation and erosion problems in the Hatchie River watershed.The source of the Mississippi section of the Hatchie River is in the sand hills southwest of Corinth, Mississippi (fig. 1). This section of the Hatchie River flows northward in an artificial drainage canal, gathering water from tributary streams that also are channelized. The drainage canal ends 2 miles south of the Tennessee State line. The Tennessee section of the Hatchie River winds north and west in a meandering natural channel to the Mississippi River. Although most of the Hatchie River tributaries are also drainage canals, the river's main stem has kept most of

Thyroid hormone disrupting activities associated with phthalate esters in water sources from Yangtze River Delta.

PubMed

Shi, Wei; Zhang, Feng-Xian; Hu, Guan-Jiu; Hao, Ying-Qun; Zhang, Xiao-Wei; Liu, Hong-Ling; Wei, Si; Wang, Xin-Ru; Giesy, John P; Yu, Hong-Xia

2012-07-01

Thyroid hormone disrupting compounds in water sources is a concern. Thyroid hormone (TH) agonist and antagonist activities of water sources from the Yangtze River, Huaihe River, Taihu Lake and ground water in the Yangtze River Delta region were evaluated by use of a TH reporter gene assay based on the green monkey kidney fibroblast (CV-1). While weak TH receptor (TR) agonist potency was observed in only one of 15 water sources, antagonist potency was present in most of the water sources. TR antagonist equivalents could be explained by the presence of dibutyl phthalate (DBP), with concentrations ranging from 2.8×10(1) to 1.6×10(3) μg DBP /L (ATR-EQ(50)s). None of the ground waters exhibited TH agonist potencies while all of the samples from Taihu Lake displayed notable TR antagonist potencies. To identify the responsible thyroid active compounds, instrumental analysis was conducted to measure a list of potential thyroid-disrupting chemicals, including organochlorine (OC) pesticides and phthalate esters. Combining the results of the instrumental analysis with those of the bioassay, DBP was determined to account for 17% to 144% of ATR-EQ(50)s in water sources. Furthermore, ATR-EQ(20-80) ranges for TR antagonist activities indicated that samples from locations WX-1 and WX-2 posed the greatest health concern and the associated uncertainty may warrant further investigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

USGS Publications Warehouse

Bartolino, James R.; Adkins, Candice B.

2012-01-01

The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Hailey, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system, which consists primarily of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on groundwater for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the groundwater resource. As part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the Wood River Valley, this report describes the hydrogeologic framework of the Wood River Valley aquifer system. Although most of the Wood River Valley aquifer system is composed of Quaternary-age sediments and basalts of the Wood River Valley and its tributaries, older igneous, sedimentary, or metamorphic rocks that underlie these Quaternary deposits also are used for water supply. It is unclear to what extent these rocks are hydraulically connected to the main part of Wood River Valley aquifer system and thus whether they constitute separate aquifers. Paleozoic sedimentary rocks in and near the study area that produce water to wells and springs are the Phi Kappa and Trail Creek Formations (Ordovician and Silurian), the Milligen Formation (Devonian), and the Sun Valley Group including the Wood River Formation (Pennsylvanian-Permian) and the Dollarhide Formation (Permian). These sedimentary rocks are intruded by granitic rocks of the Late Cretaceous Idaho batholith. Eocene Challis Volcanic Group rocks overlie all of the older rocks (except where removed by erosion). Miocene Idavada Volcanics are found in the southern part of the study area. Most of these rocks have been folded, faulted, and

Recent coarsening of sediments on the southern Yangtze subaqueous delta front: A response to river damming

NASA Astrophysics Data System (ADS)

Yang, H. F.; Yang, S. L.; Meng, Y.; Xu, K. H.; Luo, X. X.; Wu, C. S.; Shi, B. W.

2018-03-01

After more than 50,000 dams were built in the Yangtze basin, especially the Three Gorges Dam (TGD) in 2003, the sediment discharge to the East China Sea decreased from 470 Mt/yr before dams to the current level of 140 Mt/yr. The delta sediment's response to this decline has interested many researchers. Based on a dataset of repeated samplings at 44 stations in this study, we compared the surficial sediment grain sizes in the southern Yangtze subaqueous delta front for two periods: pre-TGD (1982) and post-TGD (2012). External factors of the Yangtze River, including water discharge, sediment discharge and suspended sediment grain size, were analysed, as well as wind speed, tidal range and wave height of the coastal ocean. We found that the average median size of the sediments in the delta front coarsened from 8.0 μm in 1982 to 15.4 μm in 2012. This coarsening was accompanied by a decrease of clay components, better sorting and more positive skewness. Moreover, the delta morphology in the study area changed from an overall accretion of 1.0 cm/yr to an erosion of - 0.6 cm/yr. At the same time, the riverine sediment discharge decreased by 70%, and the riverine suspended sediment grain size increased from 8.4 μm to 10.5 μm. The annual wind speed and wave height slightly increased by 2% and 3%, respectively, and the tidal range showed no change trend. Considering the increased wind speed and wave height, there was no evidence that the capability of the China Coastal Current to transport sediment southward has declined in recent years. The sediment coarsening in the Yangtze delta front was thus mainly attributed to the delta's transition from accumulation to erosion which was originally generated by river damming. These findings have important implications for sediment change in many large deltaic systems due to worldwide human impacts.

Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China.

PubMed

Liu, Lusan; Zhou, Juan; Zheng, Binghui; Cai, Wenqian; Lin, Kuixuan; Tang, Jingliang

2013-07-15

Between 1972 and 2009, evidence of red tide outbreaks in the Yangtze River Estuary and adjacent waters was collected. A geographic information system (GIS) was used to analyze the temporal and spatial distribution of these red tides, and it was subsequently used to map the distribution of these events. The results show that the following findings. (1) There were three red tide-prone areas: outside the Yangtze River Estuary and the eastern coast of Sheshan, the Huaniaoshan-Shengshan-Gouqi waters, and the Zhoushan areas and eastern coast of Zhujiajian. In these areas, red tides occurred 174 total times, 25 of which were larger than 1000 km(2) in areal extent. After 2000, the frequency of red tide outbreaks increased significantly. (2) During the months of May and June, the red tide occurrence in these areas was 51% and 20%, respectively. (3) Outbreaks of the dominant red tide plankton species Prorocentrum dong-haiense, Skeletonema costatum, Prorocentrum dantatum, and Noctiluca scientillan occurred 38, 35, 15, and 10 times, respectively, during the study interval. Copyright © 2013 Elsevier Ltd. All rights reserved.

Study on Spatial Spillover Effects of Logistics Industry Development for Economic Growth in the Yangtze River Delta City Cluster Based on Spatial Durbin Model

PubMed Central

Xu, Xinxing

2017-01-01

The overall entropy method is used to evaluate the development level of the logistics industry in the city based on a mechanism analysis of the spillover effect of the development of the logistics industry on economic growth, according to the panel data of 26 cities in the Yangtze River delta. On this basis, the paper uses the spatial durbin model to study the direct impact of the development of the logistics industry on economic growth and the spatial spillover effect. The results show that the direct impact coefficient of the development of the logistics industry in the Yangtze River Delta urban agglomeration on local economic growth is 0.092, and the significant spatial spillover effect on the economic growth in the surrounding area is 0.197. Compared with the labor force input, capital investment and the degree of opening to the world, and government functions, the logistics industry’s direct impact coefficient is the largest, other than capital investment; the coefficient of the spillover effect is higher than other control variables, making it a “strong engine” of the Yangtze River Delta urban agglomeration economic growth. PMID:29207555

Study on Spatial Spillover Effects of Logistics Industry Development for Economic Growth in the Yangtze River Delta City Cluster Based on Spatial Durbin Model.

PubMed

Xu, Xinxing; Wang, Yuhong

2017-12-04

The overall entropy method is used to evaluate the development level of the logistics industry in the city based on a mechanism analysis of the spillover effect of the development of the logistics industry on economic growth, according to the panel data of 26 cities in the Yangtze River delta. On this basis, the paper uses the spatial durbin model to study the direct impact of the development of the logistics industry on economic growth and the spatial spillover effect. The results show that the direct impact coefficient of the development of the logistics industry in the Yangtze River Delta urban agglomeration on local economic growth is 0.092, and the significant spatial spillover effect on the economic growth in the surrounding area is 0.197. Compared with the labor force input, capital investment and the degree of opening to the world, and government functions, the logistics industry's direct impact coefficient is the largest, other than capital investment; the coefficient of the spillover effect is higher than other control variables, making it a "strong engine" of the Yangtze River Delta urban agglomeration economic growth.

Hydrologic conditions in the Bill Williams River National Wildlife Refuge and Planet Valley, Arizona, 2000

USGS Publications Warehouse

Wilson, Richard P.; Owen-Joyce, Sandra J.

2002-01-01

During a period of sustained base-flow conditions in the Bill Williams River below Alamo Dam in west central Arizona from March to July 2000, the channel of the river through Planet Valley was dry, and the water table sloped almost due west parallel to the main slope of the flood plain. Water from the river infiltrated into the channel bottom at the head of Planet Valley, moved downgradient in the subsurface, and reappeared in the channel about 0.3 mile downstream from the east boundary of the Bill Williams River National Wildlife Refuge. A river aquifer in hydraulic connection with the Bill Williams River was mapped from a point 6.3 miles upstream from Highway 95 to the upstream end of Planet Valley. Formations that make up the river aquifer in Planet Valley are younger alluvium, older alluviums, and fanglomerate. Total thickness of the river aquifer probably is less than 200 feet in the bedrock canyons to as much as 1,035 feet in Planet Valley. The purpose of this study was to investigate the current hydrologic conditions along the Bill Williams River, which included an inventory of wells within the river aquifer of the Colorado River and in Planet Valley, and to determine the configuration of the water table. A map shows the elevation and configuration of the water table from the east end of Planet Valley to the confluence of the Bill Williams River with Lake Havasu.

Effects of Spartina alterniflora invasion on soil respiration in the Yangtze River estuary, China.

PubMed

Bu, Naishun; Qu, Junfeng; Li, Zhaolei; Li, Gang; Zhao, Hua; Zhao, Bin; Li, Bo; Chen, Jiakuan; Fang, Changming

2015-01-01

Many studies have found that plant invasion can enhance soil organic carbon (SOC) pools, by increasing net primary production (NPP) and/or decreased soil respiration. While most studies have focused on C input, little attention has been paid to plant invasion effects on soil respiration, especially in wetland ecosystems. Our study examined the effects of Spartina alterniflora invasion on soil respiration and C dynamics in the Yangtze River estuary. The estuary was originally occupied by two native plant species: Phragmites australis in the high tide zone and Scirpus mariqueter in the low tide zone. Mean soil respiration rates were 185.8 and 142.3 mg CO2 m(-2) h(-1) in S. alterniflora and P. australis stands in the high tide zone, and 159.7 and 112.0 mg CO2 m(-2) h(-1) in S. alterniflora and S. mariqueter stands in the low tide zone, respectively. Aboveground NPP (ANPP), SOC, and microbial biomass were also significantly higher in the S. alterniflora stands than in the two native plant stands. S. alterniflora invasion did not significantly change soil inorganic carbon or pH. Our results indicated that enhanced ANPP by S. alterniflora exceeded invasion-induced C loss through soil respiration. This suggests that S. alterniflora invasion into the Yangtze River estuary could strengthen the net C sink of wetlands in the context of global climate change.

[Ciliate diversity and spatiotemporal variation in surface sediments of Yangtze River estuary hypoxic zone].

PubMed

Feng, Zhao; Kui-Dong, Xu; Zhao-Cui, Meng

2012-12-01

By using denaturing gradient gel electrophoresis (DGGE) and sequencing as well as Ludox-QPS method, an investigation was made on the ciliate diversity and its spatiotemporal variation in the surface sediments at three sites of Yangtze River estuary hypoxic zone in April and August 2011. The ANOSIM analysis indicated that the ciliate diversity had significant difference among the sites (R = 0.896, P = 0.0001), but less difference among seasons (R = 0.043, P = 0.207). The sequencing of 18S rDNA DGGE bands revealed that the most predominant groups were planktonic Choreotrichia and Oligotrichia. The detection by Ludox-QPS method showed that the species number and abundance of active ciliates were maintained at a higher level, and increased by 2-5 times in summer, as compared with those in spring. Both the Ludox-QPS method and the DGGE technique detected that the ciliate diversity at the three sites had the similar variation trend, and the Ludox-QPS method detected that there was a significant variation in the ciliate species number and abundance between different seasons. The species number detected by Ludox-QPS method was higher than that detected by DGGE bands. Our study indicated that the ciliates in Yangtze River estuary hypoxic zone had higher diversity and abundance, with the potential to supply food for the polyps of jellyfish.

Effects of Spartina alterniflora Invasion on Soil Respiration in the Yangtze River Estuary, China

PubMed Central

Bu, Naishun; Qu, Junfeng; Li, Zhaolei; Li, Gang; Zhao, Hua; Zhao, Bin; Li, Bo; Chen, Jiakuan; Fang, Changming

2015-01-01

Many studies have found that plant invasion can enhance soil organic carbon (SOC) pools, by increasing net primary production (NPP) and/or decreased soil respiration. While most studies have focused on C input, little attention has been paid to plant invasion effects on soil respiration, especially in wetland ecosystems. Our study examined the effects of Spartina alterniflora invasion on soil respiration and C dynamics in the Yangtze River estuary. The estuary was originally occupied by two native plant species: Phragmites australis in the high tide zone and Scirpus mariqueter in the low tide zone. Mean soil respiration rates were 185.8 and 142.3 mg CO2 m−2 h−1 in S. alterniflora and P. australis stands in the high tide zone, and 159.7 and 112.0 mg CO2 m−2 h−1 in S. alterniflora and S. mariqueter stands in the low tide zone, respectively. Aboveground NPP (ANPP), SOC, and microbial biomass were also significantly higher in the S. alterniflora stands than in the two native plant stands. S. alterniflora invasion did not significantly change soil inorganic carbon or pH. Our results indicated that enhanced ANPP by S. alterniflora exceeded invasion-induced C loss through soil respiration. This suggests that S. alterniflora invasion into the Yangtze River estuary could strengthen the net C sink of wetlands in the context of global climate change. PMID:25799512

[Terrain gradient effect of ecosystem service value in middle reach of Yangtze River, China].

PubMed

Yang, Suo Hua; Hu, Shou Geng; Qu, Shi Jin

2018-03-01

Using land use data in the year 1995, 2005 and 2014, this study estimated the ecosystem service value (ESV) in each county located in the middle reach of Yangtze River and analyzed its spatiotemporal variation features and terrain gradient effects based on "the equivalent value per unit area of ecosystem services in China". The results showed that ESV in the middle reach of Yangtze River was generally higher in mountainous area but lower in plain region, with an obvious terrain gradient effect. Specifically, the relationship of the relief degree of land surface (RDLS) and the ESV showed significant logarithm function at county scale with a high curve fitting degree of 0.53. The ESV increased from 400.35×10 4 yuan·km -2 to 554.57×10 4 yuan·km -2 with the increasing RDLS (grade 1-5) in 2014. During 1995-2004, the ecosystem service value variation changed from decreasing to stable with the increases of the RDLS. With a perspective of ecosystem service values, the value of food production and waste treatment service value decreased with the increase of the RDLS, while the others increased in general, such as the production of raw materials and gas regulation service value, because of the influences of dynamic land use structure in varied topography and distinct dominant ecosystem services from different land types.

Birds of the St. Croix River valley: Minnesota and Wisconsin

USGS Publications Warehouse

Faanes, Craig A.

1981-01-01

The St. Croix River Valley encompasses nearly 11,550 km2 in east-central Minnesota and northwestern Wisconsin. A wide range of habitats are available for birds including upland oak, lowland deciduous, maple-basswood, lowland and upland coniferous forests, natural basin wetlands, and grasslands. Situated in the north-central region of the United States, the valley is a biological 'crossroads' for many species. Because of the mixed affinities of plant communities, the valley includes the northern and southern range limits for a number of species. Also, because the valley lies near the forest-prairie transition zone, many typical western breeding species (e.g. pintail, western meadowlark, yellow-headed blackbird) breed in proximity to typical eastern species such as tufted titmouse, eastern meadowlark, and cardinal. From 1966 to 1980, I conducted extensive surveys of avian distribution and abundance in the St. Croix River Valley. I have supplemented the results of these surveys with published and unpublished observations contributed by many ornithologists. These additional data include compilations from Christmas Bird Counts sponsored by the National Audubon Society and from the Breeding Bird Survey coordinated by the U.S. Fish and Wildlife Service. Three hundred fourteen species have been recorded in the study area; data are presented on the migration period, nesting season distribution, winter distribution, relative abundance, and habitat use of each species. Recognizing the uniqueness of the area, and its importance not only to wildlife but also to man, the U.S. Congress designated the St. Croix a National Scenic Riverway. This action provided a considerable degree of protection to lands along and directly adjacent to the river. Unfortunately, no similar legal measure exists to protect lands away from the river. With the exception of the northern quarter of the St. Croix River Valley, agricultural interests have made significant inroads into the habitat base. The

Phenomena and characteristics of barrier river reaches in the middle and lower Yangtze River, China

NASA Astrophysics Data System (ADS)

You, Xingying; Tang, Jinwu

2017-06-01

Alluvial river self-adjustment describes the mechanism whereby a river that was originally in an equilibrium state of sediment transport encounters some disturbance that destroys the balance and results in responses such as riverbed deformation. A systematic study of historical and recent aerial photographs and topographic maps in the Middle and Lower Reaches of the Yangtze River (MLYR) shows that river self-adjustment has the distinguishing feature of transferring from upstream to downstream, which may affect flood safety, waterway morphology, bank stability, and aquatic environmental safety over relatively long reaches downstream. As a result, it is necessary to take measures to control or block this transfer. Using the relationship of the occurrence time of channel adjustments between the upstream and downstream, 34 single-thread river reaches in the MLYR were classified into four types: corresponding, basically corresponding, basically not corresponding, not corresponding. The latter two types, because of their ability to prevent upstream channel adjustment from transferring downstream, are called barrier river reaches in this study. Statistics indicate that barrier river reaches are generally single thread and slightly curved, with a narrow and deep cross-sectional morphology, and without flow deflecting nodes in the upper and middle parts of reaches. Moreover, in the MLYR, barrier river reaches have a hydrogeometric coefficient of {<}{4}, a gradient {>}1.2‱, a silty clay content of the concave bank {>}{9.5}%, and a median diameter of the bed sediment {>}{0.158} mm. The barrier river reach mechanism lies in that can effectively centralise the planimetric position of the main stream from different upstream directions, meaning that no matter how the upper channel adjusts, the main stream shows little change, providing relatively stable inflow conditions for the lower reaches. Regarding river regulation, it is necessary to optimise the benefits of barrier river

GF-1 and Landsat observed a 40-year wetland spatiotemporal variation and its coupled environmental factors in Yangtze River estuary

NASA Astrophysics Data System (ADS)

Sun, Nan; Zhu, Weining; Cheng, Qian

2018-07-01

Wetlands are health indicators of aquatic ecosystems and also vulnerable to regional environmental and socio-economic changes. For exploring wetland spatiotemporal variations in estuarine and coastal regions of the Yangtze River, we extracted wetland information from 40-year time-series images of Landsat, GF-1, and other satellites, using the classification method of decision tree. Potential environmental and socio-economic factors which may drive wetland variations were analyzed. Results show that the wetland area in Yangtze River estuary has increased 663 km2, but it was only contributed by the increasing of human-made wetlands (767 km2), which were mostly caused by economic growth and constructions of human-made hydro-projects in Yangtze Delta. In comparison, natural wetlands, such as tidal flats and marshes, have decreased 163 km2. Land reclamation has changed these natural wetlands into reservoirs, aquaculture ponds and paddy fields. Wetlands in Shanghai and Qidong urban regions were mainly affected by human activities, while wetland variations in Chongming Island were mainly controlled by natural factors such as the upstream discharge, precipitation, diurnal variation of tidal level and long-term sea level rising. The general trend is that the natural wetland was transformed into the human-made wetland, and the human-made wetland was transformed into construction land.

Spatio-temporal distribution and environmental risk of sedimentary heavy metals in the Yangtze River Estuary and its adjacent areas.

PubMed

Chen, Bin; Liu, Jian; Qiu, Jiandong; Zhang, Xilin; Wang, Shuang; Liu, Jinqing

2017-03-15

Twenty-five surface sediments and one sediment core sample were collected from the study area. Grain size, major elements, and heavy metals were determined. The content of fine-grained sediments (silt and clay), as well as the concentrations of major elements and heavy metals, showed seaward decreasing trends, with high content in the coastal areas of the East China Sea (ECS) and south west of Jeju Island. Low enrichment factor (EF) and geoaccumulation index (Igeo) values were found, indicating that the ecological risk of heavy metals was low. The EF values obtained from the high-resolution sedimentary records of heavy metals in the Yangtze River Estuary could be divided into Stage 1 (1950s to the late 1970s) and Stage 2 (late 1970s to the current sampling day), which coincided with economic development of the Yangtze River Basin, implementation of environmental protection, and impoundment of the Three Gorges Dam. Copyright © 2016. Published by Elsevier Ltd.

KAWEAH RIVER VALLEY, WITH GENERALS HIGHWAY AT LEFT, MORO ROCK ...

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

KAWEAH RIVER VALLEY, WITH GENERALS HIGHWAY AT LEFT, MORO ROCK IN LEFT BACKGROUND. WITH PHOTO NO. 81, THIS SHOT FORMS A PANORAMA OF THE ROAD ALONG THE KAWEAH RIVER - Generals Highway, Three Rivers, Tulare County, CA

Preliminary results of hydrogeologic investigations Humboldt River Valley, Winnemucca, Nevada

USGS Publications Warehouse

Cohen, Philip M.

1964-01-01

Most of the ground water of economic importance and nearly all the ground water closely associated with the flow o# the Humboldt River in the. 40-mile reach near Winnemucca, Nev., are in unconsolidated sedimentary deposits. These deposits range in age from Pliocene to Recent and range in character from coarse poorly sorted fanglomerate to lacustrine strata of clay, silt, sand, and gravel. The most permeable deposit consists of sand and gravel of Lake Lahontan age--the so-called medial gravel unit--which is underlain and overlain by fairly impermeable silt and clay also of Lake Lahontan age. The ultimate source of nearly all the water in the study area is precpitation within the drainage basin of the Humboldt River. Much of this water reaches the study, area as flow or underflow of the Humboldt River and as underflow from other valleys tributary to the study area. Little if any flow from the tributary streams in the study area usually reaches the Humboldt River. Most of the tributary streamflow within the study area evaporates or is transpired by vegetation, but a part percolates downward through unconsolidated deposits of the alluvial fans flanking the mountains and move downgradient as ground-water underflow toward the Humboldt River. Areas that contribute significant amounts of ground-water underflow to. the valley of the Humboldt River within the study area are (1) the valley of the Humboldt River upstream from the study area, (2) the Pole Creek-Rock Creek area, (3) Paradise Valley, and (4) Grass Valley and the northwestern slope of the Sonoma Range. The total average underflow from these areas in the period 1949-61 was about 14,000-19,000 acre-feet per year. Much of this underflow discharged into the Humboldt River within the study area and constituted a large part of the base flow of the river. Streamflow in the Humboldt River increases substantially in the early spring, principally because of runoff to the river in the reaches upstream from the study area

Contribution of the upper river, the estuarine region, and the adjacent sea to the heavy metal pollution in the Yangtze Estuary.

PubMed

Yin, Su; Wu, Yuehan; Xu, Wei; Li, Yangyang; Shen, Zhenyao; Feng, Chenghong

2016-07-01

To determine whether the discharge control of heavy metals in the Yangtze River basin can significantly change the pollution level in the estuary, this study analyzed the sources (upper river, the estuarine region, and the adjacent sea) of ten heavy metals (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, and Zn) in dissolved and particulate phases in the surface water of the estuary during wet, normal, and dry seasons. Metal sources inferred from section fluxes agree with those in statistical analysis methods. Heavy metal pollution in the surface water of Yangtze Estuary primarily depends on the sediment suspension and the wastewater discharge from estuary cities. Upper river only constitutes the main source of dissolved heavy metals during the wet season, while the estuarine region and the adjacent sea (especially the former) dominate the dissolved metal pollution in the normal and dry seasons. Particulate metals are mainly derived from sediment suspension in the estuary and the adjacent sea, and the contribution of the upper river can be neglected. Compared with the hydrologic seasons, flood-ebb tides exert a more obvious effect on the water flow directions in the estuary. Sediment suspension, not the upper river, significantly affects the suspended particulate matter concentration in the estuary. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dynamics of the lakes in the middle and lower reaches of the Yangtze River basin, China, since late nineteenth century.

PubMed

Cui, Lijuan; Gao, Changjun; Zhao, Xinsheng; Ma, Qiongfang; Zhang, Manyin; Li, Wei; Song, Hongtao; Wang, Yifei; Li, Shengnan; Zhang, Yan

2013-05-01

The middle and lower reaches of the Yangtze River basin have the most representative and largest concentration of freshwater lakes in China. However, the size and number of these lakes have changed considerably over the past century due to the natural and anthropogenic impact. The lakes, larger than 10 km(2) in size, were chosen from relief maps and remotely sensed images in 1875, 1950, 1970, 1990, 2000, and 2008 to study the dynamics of lakes in the middle and lower reaches of the Yangtze River basin and to examine the causes and consequences of these changes. Results indicated that there was a dramatic reduction in lake areas, which decreased by 7,841.2 km(2) (42.64 %) during the study period (1875-2008), and the number of lakes in this region changed moderately. Meanwhile, a large number of lakes in the middle and lower reaches of the Yangtze River basin were directly converted into paddy fields, ponds, building lands, or other land-use types over the study period. Therefore, all kinds of lake reclamation should be identified as the major driving factors for the loss of lake in this region. Furthermore, flooding, soil erosion, and sedimentation were also the main factors which triggered lake changes in different periods. Some wetland conservation and restoration projects have been implemented since the 1970s, but they have not reversed the lake degradation. These findings were of great importance to managers involved in making policy for the conservation of lake ecosystems and the utilization of lake resources.

Habitat and Populations of the Valley Elderberry Longhorn Beetle Along the Sacramento River

Treesearch

F. Jordan Lang; James D. Jokerst; Gregory E. Sutter

1989-01-01

Prior to 1985, the valley elderberry longhorn beetle, a threatened species protected under the federal Endangered Species Act, was known only from northern California riparian areas along the American River and Putah Creek in the Sacramento Valley, and along several rivers in the northern San Joaquin Valley. During 1985-1987, our study extended the known range of the...

Synthetic river valleys: Creating prescribed topography for form-process inquiry and river rehabilitation design

NASA Astrophysics Data System (ADS)

Brown, R. A.; Pasternack, G. B.; Wallender, W. W.

2014-06-01

The synthesis of artificial landforms is complementary to geomorphic analysis because it affords a reflection on both the characteristics and intrinsic formative processes of real world conditions. Moreover, the applied terminus of geomorphic theory is commonly manifested in the engineering and rehabilitation of riverine landforms where the goal is to create specific processes associated with specific morphology. To date, the synthesis of river topography has been explored outside of geomorphology through artistic renderings, computer science applications, and river rehabilitation design; while within geomorphology it has been explored using morphodynamic modeling, such as one-dimensional simulation of river reach profiles, two-dimensional simulation of river networks, and three-dimensional simulation of subreach scale river morphology. To date, no approach allows geomorphologists, engineers, or river rehabilitation practitioners to create landforms of prescribed conditions. In this paper a method for creating topography of synthetic river valleys is introduced that utilizes a theoretical framework that draws from fluvial geomorphology, computer science, and geometric modeling. Such a method would be valuable to geomorphologists in understanding form-process linkages as well as to engineers and river rehabilitation practitioners in developing design surfaces that can be rapidly iterated. The method introduced herein relies on the discretization of river valley topography into geometric elements associated with overlapping and orthogonal two-dimensional planes such as the planform, profile, and cross section that are represented by mathematical functions, termed geometric element equations. Topographic surfaces can be parameterized independently or dependently using a geomorphic covariance structure between the spatial series of geometric element equations. To illustrate the approach and overall model flexibility examples are provided that are associated with

In vitro assessment of thyroid hormone disrupting activities in drinking water sources along the Yangtze River.

PubMed

Hu, Xinxin; Shi, Wei; Zhang, Fengxian; Cao, Fu; Hu, Guanjiu; Hao, Yingqun; Wei, Si; Wang, Xinru; Yu, Hongxia

2013-02-01

The thyroid hormone disrupting activities of drinking water sources from the lower reaches of Yangtze River were examined using a reporter gene assay based on African green monkey kidney fibroblast (CV-1) cells. None of the eleven tested samples showed thyroid receptor (TR) agonist activity. Nine water samples exhibited TR antagonist activities with the equivalents referring to Di-n-butyl phthalate (DNBP) (TR antagonist activity equivalents, ATR-EQ(50)s) ranging from 6.92 × 10(1) to 2.85 × 10(2) μg DNBP/L. The ATR-EQ(50)s and TR antagonist equivalent ranges (ATR-EQ(30-80) ranges) for TR antagonist activities indicated that the water sample from site WX-8 posed the greatest health risks. The ATR-EQ(80)s of the water samples ranging from 1.56 × 10(3) to 6.14 × 10(3) μg DNBP/L were higher than the NOEC of DNBP. The results from instrumental analysis showed that DNBP might be responsible for the TR antagonist activities in these water samples. Water sources along Yangtze River had thyroid hormone disrupting potential. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nontarget Mass Spectrometry Reveals New Perfluoroalkyl Substances in Fish from the Yangtze River and Tangxun Lake, China.

PubMed

Liu, Yanna; Qian, Manli; Ma, Xinxin; Zhu, Lingyan; Martin, Jonathan W

2018-05-15

Nontarget high-resolution mass spectrometry (Nt-HRMS) has been proven useful for the identification of unknown poly- and perfluoroalkyl substances (PFASs) in commercial products and water, but applications to biological samples are limited. China is the major PFAS-manufacturing nation; thus, here, we adapted our Nt-HRMS methods to fish collected from the Yangtze River and Tangxun Lake to discover potentially bioaccumulative PFASs in aquatic organisms destined for human consumption. In addition to traditional PFASs, over 330 other fluorinated analytes belonging to 10 classes of PFASs were detected among the pooled fish livers, including 6 sulfonate classes, 2 amine classes, 1 carboxylate class, and 1 N-heterocycle class. One class was detected in samples from both locations, 8 classes were detected exclusively in Tangxun Lake fish, and 1 class was detected exclusively in Yangtze River fish, 10 km downstream of a fluorochemical manufacturing site where we first reported these substances in wastewater 3 years ago. Overall, 4 of the PFAS classes (>165 analytes) are reported for the first time here. Wider monitoring and toxicological testing should be a priority for understanding the health risks posed to people and wildlife exposed to these substances.

A comparative study of golf industry between Yangtze River Delta, China and Central Japan

NASA Astrophysics Data System (ADS)

Yang, Yangfan; Jin, Pingbin; Gong, Huiwen

2018-03-01

As a competition event of the 2016 Olympic Game, golf sport has aroused great attention around the world. And the Yangtze River Delta(YRD) in China, has already got certain basis and qualifications of developing golf industry, but somehow far from meeting the great potential demand of the market. This research selects the Yangtze River Delta (YRD) and Central Japan (CJ), which are indifferent golf developing stages, as the objectives. Comparative studies are being carried out with an aim of revealing the discrepancies of golf industry in selected regions. The correlations between golf industry and regional economic developing level have been explored as well. Mainly based on a geographical perspective, this research presents an initial effort to combine approaches of setting comparative indexes and spatial analysis, so that golf industry of selected regions will be compared in all directions. The results reveal that great gaps exist in YRD and CJ in terms of golf construction, service, and golf consumption. Problems in developing golf industry in YRD are identified based on the empirical results. A long-term golf development in YRD that deviating from the realistic demand is attributed to both government policies and the operational principles that the market subjects hold. Based on a comparative empirical study, suggestions relating to the government as well as the market players are put forward, with an aim of guiding the golf industry to develop in a sustainable way.

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

PubMed

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

2013-05-01

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

Refraction seismic studies in the Miami River, Whitewater River, and Mill Creek valleys, Hamilton and Butler Counties, Ohio

USGS Publications Warehouse

Watkins, Joel S.

1963-01-01

Between September 17 and November 9, 1962, the U.S. Geological Survey, in cooperation with Ohio Division of Water, Miami Conservancy District, and c,ty of Cincinnati, Ohio, co.,:ducted a refraction seismic study in Hamilton and Butler Counties, southwest Ohio. The area lies between Hamilton, Ohio, and the Ohio River and includes a preglacial valley now occupied by portions of the Miami River, Whitewater River, and Mill Creek. The valley is partially filled with glacial debris which yields large quantities of good-quality water. The object of the study was to determine the thickness of these glacial deposits and the shape of the preglacial valley.

Water in the Humboldt River Valley near Winnemucca, Nevada

USGS Publications Warehouse

Cohen, Philip M.

1966-01-01

Most of the work of the interagency Humboldt River Research Project in the Winnemucca reach of the Humboldt River valley has been completed. More than a dozen State and Federal agencies and several private organizations and individuals participated in the study. The major objective of the project, which began in 1959, is to evaluate the water resources of the entire Humboldt River basin. However, because of the large size of the basin, most of the work during the first 5 years of the project was done in the Winnemucca area. The purpose of this report is to summarize briefly and simply the information regarding the water resources of the Winnemucca area-especially the quantitative aspects of the flow system-given in previous reports of the project. The Winnemucca reach of the Humboldt River valley, which is in north-central Nevada, is about 200 miles downstream from the headwaters of the Humboldt River and includes that part of the valley between the Comus and Rose Creek gaging stations. Average annual inflow to the storage area (the valley lowlands) in the Winnemucca reach in water years 1949-62 was about 250,000 acre-feet. Of this amount, about 68 percent was Humboldt River streamflow, as measured at the Comus gaging station, 23 percent was precipitation directly on the storage area, 6 percent was ground-water inflow, and about 3 percent was tributary streamflow. Average annual streamflow at the Rose Creek gaging station during the same period was about 155,000 acre-feet, or about 17,000 acre-feet less than that at the Comus gaging station. Nearly all the streamflow lost was consumed by evapotranspiration in the project area. Total average annual evapotranspiration loss during the period was about 115,000 acre-feet, or about 42 percent of the total average annual outflow. The most abundant ions in the ground and surface water in the area are commonly sodium and bicarbonate. Much of the water has a dissolved-solids content that ranges from 500 to 750 parts per

[Surveillance and risk assessment system of schistosomiasis in Jiangsu Province Ⅲ Risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City].

PubMed

Yin-Ping, Zuo; Dao-Jian, Zhu; Guang-Lin, Du; Kai, Tang; Yu-Cai, Ma; Zheng-Qiu, Zhang; Shao-Zhou, Chen; Fubiao, Wang; Hong-Ping, Tang; Jin, Zhang; Le-Ping, Sun

2016-08-02

To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City, so as to provide evidences for establishing a post-transmission surveillance system for schistosomiasis in marshland regions. The water infectivity, floating boatmen and fishermen infection, reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City, including Guangling, Hanjiang, Jiangdu, Yizheng and Development Zone, and the transmission factors and risky characteristics were assessed after interruption of schistosomiasis transmission in marshland regions. A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed, after breeding, their overall survival rate was 99.33%; 1 490 were dissected, with no schistosome infection. Of the 5 576 floating boatmen and fishermen examined, no schistosome infection was observed, and among the 3 566 domestic animals (including 171 cattle, 1 895 sheep and 1 500 pigs), no infections were detected. During the period between January and March, 2016, there were 3 200 mouse traps placed on 8 marshlands, and 62 wild mice were captured from 6 marshlands, with a capture rate of 1.94%, and no schistosomeinfected wild mice were seen. In addition, there were 35 pieces of fresh wild feces captured from 7 marshlands, including 11 pieces of bovine feces (31.43%), 17 pieces of sheep feces (48.57%), 2 pieces of dog feces (5.71%) and 5 pieces of other feces (14.29%), and no infections were detected. There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However, the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.

Hyperspectral Imaging of River Systems

DTIC Science & Technology

2010-09-30

98) Prescribed by ANSI Std Z39-18 2 2. As soon as it is available we will collect HICOTM data for the Yangtze River and adjacent coastal...the Yangtze and other river systems. The goal is to validate our algorithms and to further our understanding of this important river and the East...For the past year we have been collecting HICOTM data for the Columbia (Fig. 3) and Yangtze Rivers (Fig. 4). There are many constraints on data

An integrated environmental improvement of marshlands: impact on control and elimination of schistosomiasis in marshland regions along the Yangtze River, China.

PubMed

Sun, Le-Ping; Wang, Wei; Zuo, Yin-Ping; Zhang, Zheng-Qiu; Hong, Qing-Biao; Yang, Guo-Jing; Zhu, Hong-Ru; Liang, You-Sheng; Yang, Hai-Tao

2017-03-22

Schistosomiasis is a global snail-transmitted infectious disease of poverty. Transmission control had been achieved in China in 2015 after the control efforts for over 60 years. Currently, the remaining core regions endemic for Schistosoma japonicum are mainly located in the marshland and lake regions along the Yangtze River basin. During the period from 2001 through 2015, an integrated environmental improvement of the marshlands was carried out through the implementation of industrial, agricultural and resources development projects in Yizheng County along the Yangtze River. S. japonicum infection in humans, livestock and snails was estimated by serology, stool examination, hatching technique and microscopy during the 15-year study period to evaluate the effect of the integrated environmental improvement on control and elimination of schistosomiasis. A 0.05% overall rate of S. japonicum infection was observed in snails during the 15-year study period, and no infected snails were detected since 2012. The overall prevalence of S. japonicum infection was 0.09% in humans during the study period, and no human infection was found since 2012. In addition, only 13 bovines were identified with S. japonicum infection in 2003 during the 15-year study period, and since 2004, no infection was found in livestock. The results of the present study demonstrate that the implementation of industrial, agricultural and water resources development projects, not only alters snail habitats in marshland regions, and promotes local economic development, which appears a win-to-win strategy to block the transmission of S. japonicum and accelerate socio-economic development along the Yangtze River.

Dependence of Wetland Vegetation on Hydrological Regime in a Large Floodplain Lake (Poyang Lake) in the Middle Yangtze River

NASA Astrophysics Data System (ADS)

Zhang, Q.; Tan, Z.; Xu, X.

2017-12-01

Exemplified in the Yangtze River floodplain lake, Poyang Lake, investigations were carried out to examine the dependence of vegetation on hydrological variables. The Lake is one of the few lakes that remain naturally connected to the Yangtze River. The Lake surface expanses to 4000 km2 in wet seasons, and reduces to less than 1000 km2 in dry seasons, creating some 3000 km2 vital wetland habitats for many animals. Remote sensing was used to obtain the spatial distribution of wetland vegetations. A lake hydrodynamic model using MIKE 21 was employed to determine the variability of wetland inundation. In-situ high time frequency observations of climate, soil moisture, and groundwater depth were also conducted in a typical wetland transect of 1 km long. Vegetations were sampled periodically to obtain species composition, diversity and biomass. Results showed that the spatial distribution of vegetation highly depended on the inundation duration and depth. Optimal hydrological variables existed for the typical vegetations in Poyang Lake wetland. Numerical simulations using HYDRUS-1D further demonstrated that both groundwater depth and soil moisture had significant effects on the growth of vegetation and the water demand in terms of transpiration, even in a wet climate zone such as middle Yangtze River. It was found that the optimal groundwater depths existed for both above- and belowground biomass. Simulation scenarios indicated that climate changes and human modification of hydrology would affect the water usage of vegetation and may cause a strategic adaptation of the vegetation to the stressed hydrological conditions. The study revealed new knowledge on the high dependence of wetland vegetation on both surface water regime and groundwater depths, in wet climate zone. Outcomes of this study may provide support for an integrated management of balancing water resources development and wetland sustainability maintenance in Poyang Lake, and other floodplain wetlands, with

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

PubMed

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

2014-09-01

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

Iron and nutrient content of wind-erodible sediment in the ephemeral river valleys of Namibia

NASA Astrophysics Data System (ADS)

Dansie, A. P.; Wiggs, G. F. S.; Thomas, D. S. G.

2017-08-01

Research concerning the global distribution of aeolian dust sources has principally focussed on salt/clay pan and desiccated lacustrine emission areas. In southern Africa such sources are identified as Etosha Pan in northern Namibia and Makgadikgadi Pans in northern Botswana. Dust emitting from ephemeral river valleys, however, has been largely overlooked. Rivers are known nutrient transport pathways and the flooding regimes of ephemeral river valleys frequently replenish stores of fine sediment which, on drying, can become susceptible to aeolian erosion. Such airborne sediment may be nutrient rich and thus be significant for the fertilisation of marine waters once deposited. This study investigates the dust source sediments from three ephemeral river valleys in Namibia in terms of their particle size distribution and their concentrations of bioavailable N, P and Fe. We compare the nutrient content of these sediments from the ephemeral river valleys to those collected from Etosha and Makgadikgadi Pans and consider their relative ocean fertilising potential. Our results show that the ephemeral river valleys contain fine grained sediment similar in physical character to Etosha and Makgadikgadi Pans yet they have up to 43 times greater concentrations of bioavailable iron and enriched N and P macronutrients that are each important for ocean fertilisation. The known dust-emitting river valleys of Namibia may therefore be contributing a greater fertilisation role in the adjacent marine system than previously considered, and not-yet investigated. Given this finding a re-assessment of the potential role of ephemeral river valleys in providing nutrient-rich sediment into the aeolian and marine systems in other dryland areas is necessary.

Strengthen the collaboration between the River Basin Management Organization of China and International Environmental Specimen Bank Group.

PubMed

Tan, Lingzhi; Liu, Hui; Shu, Jinxiang; Xia, Fan

2015-02-01

Several types of emerging organic contaminants were investigated in many recent researches, such as persistent toxic substance (PTS), persistent organic pollutants (POPs), endocrine disrupters (EDs), and volatile organic compounds (VOCs). But the Chinese country standard detection methods of emerging organic pollutants were not developed with the dramatic increasing of the organic substances production. Hence, it is necessary to obtain the latest informations about the long-term storage of representative environmental specimens, which could provide scientific basis for environmental management and environmental decision-making of the water resources protection and management organization. As the significant water resource conservation organization, the Water Environment Monitoring Center of Yangtze River Basin is experienced in water environmental monitoring and records many useful water resources and environment informations. It is also our responsibility to monitor all the pollutants in water environment of the Yangtze River valley, especially the emerging organic contaminants. Meanwhile, the International Environmental Specimen Bank (IESB) accumulates lots environmental organic pollution specimens and plays a significant role in environmental monitoring. Thus, the collaboration between the two parties will be greatly helpful for each further researches and monitoring work of organic contaminants in Yangtze River Basin.

The response of grain production to changes in quantity and quality of cropland in Yangtze River Delta, China.

PubMed

Liu, Guilin; Zhang, Luocheng; Zhang, Qian; Musyimi, Zipporah

2015-02-01

Cropland in Yangtze River Delta has declined drastically since economic reforms in 1978 that led to rapid economic development. Such cropland loss due to population growth has led to a decline in grain production. This study aimed at analyzing the impact of land use changes on grain production. To achieve this, the spatiotemporal dynamics of cropland during 1980-2010 were analyzed. Irrigation and soil fertility data were used as additional lines of evidence. Cropland loss had negative impacts on grain production. About 80 and 66% of grain production decreased during 1980-2005 and 2005-2010 respectively. This decline was attributed to the conversion of cropland to built-up areas. Abandoned cropland areas were mainly concentrated in regions with high irrigation capability and high soil fertility, while cropland reclamation was mainly in areas with low irrigation and soil fertility, implying that, although cropland was reclaimed, production remained low. The decline in cropland area has reinforced the chronic food insecurity in Yangtze River Delta. This study demonstrated the response of grain production to the changes in cropland quantity and quality. It also provides scientific evidence for decision makers to protect cropland and enhance grain production. © 2014 Society of Chemical Industry.

River Network Reorganization along the Upper Yangzte, Eastern Tibet: Insights from Thermochronology and Sedimentology.

NASA Astrophysics Data System (ADS)

Gourbet, L.; Yang, R.; Fellin, M. G.; Maden, C.; Gong, J.; Jean-Louis, P.

2017-12-01

The high relief and high elevation of the southeastern margin of the Tibetan Plateau are related to tectonic uplift and the fluvial incision of the Salween, Mekong, and Yangtze rivers. The upper Yangtze is the subject of numerous debates on the evolution of its drainage area, particularly in regards to the timing and geodynamic processes, and therefore has an impact on models of the Tibetan plateau evolution. Today, portions of the course of the Yangtze are controlled by active strike-slip faults. In order to study the evolution of the Cenozoic paleoriver network, we use low-temperature thermochronometry to estimate fluvial incision and palaeoenvironmental information derived from the detrital record. The Jianchuan basin, between the Yangtze and the Red River, contains late Eocene fluvial sediments that may correspond to an ancient connection between these rivers. Sediments located further north (DongWang formation, Yunnan-Sichuan boundary) consist of unsorted conglomerates and sandstones. They are exposed on the flanks of deep valleys. These sediments do not correspond to a large riverbed such as the Yangtze but rather indicate an episode of intense sedimentation with a significant contribution from talus, followed by a >1.2 km incision by a tributary of the upper Yangtze. In the same area, we performed apatite and zircon (U-Th)/He dating on a granitic pluton that is offset by an active sinistral strike-slip fault. Mean ZHe cooling ages range from 50 to 70 Ma. Samples located above 3870 m yield mean apatite (U-Th)/He ages ranging from 30 to 40 Ma. AHe ages for samples at lower elevation range from 8 to 15 Ma. Given the crystallization age of the pluton (83 Ma, U/Pb, zircon), cooling ages reflect exhumation, not post-intrusion cooling. Further research will use thermal modeling to infer incision rates and compare results with published data.

Genome Sequence of the Freshwater Yangtze Finless Porpoise.

PubMed

Yuan, Yuan; Zhang, Peijun; Wang, Kun; Liu, Mingzhong; Li, Jing; Zheng, Jingsong; Wang, Ding; Xu, Wenjie; Lin, Mingli; Dong, Lijun; Zhu, Chenglong; Qiu, Qiang; Li, Songhai

2018-04-16

The Yangtze finless porpoise ( Neophocaena asiaeorientalis ssp. asiaeorientalis ) is a subspecies of the narrow-ridged finless porpoise ( N. asiaeorientalis ). In total, 714.28 gigabases (Gb) of raw reads were generated by whole-genome sequencing of the Yangtze finless porpoise, using an Illumina HiSeq 2000 platform. After filtering the low-quality and duplicated reads, we assembled a draft genome of 2.22 Gb, with contig N50 and scaffold N50 values of 46.69 kilobases (kb) and 1.71 megabases (Mb), respectively. We identified 887.63 Mb of repetitive sequences and predicted 18,479 protein-coding genes in the assembled genome. The phylogenetic tree showed a relationship between the Yangtze finless porpoise and the Yangtze River dolphin, which diverged approximately 20.84 million years ago. In comparisons with the genomes of 10 other mammals, we detected 44 species-specific gene families, 164 expanded gene families, and 313 positively selected genes in the Yangtze finless porpoise genome. The assembled genome sequence and underlying sequence data are available at the National Center for Biotechnology Information under BioProject accession number PRJNA433603.

Genome Sequence of the Freshwater Yangtze Finless Porpoise

PubMed Central

Yuan, Yuan; Zhang, Peijun; Wang, Kun; Liu, Mingzhong; Li, Jing; Zheng, Jinsong; Wang, Ding; Xu, Wenjie; Lin, Mingli; Dong, Lijun; Zhu, Chenglong; Qiu, Qiang

2018-01-01

The Yangtze finless porpoise (Neophocaena asiaeorientalis ssp. asiaeorientalis) is a subspecies of the narrow-ridged finless porpoise (N. asiaeorientalis). In total, 714.28 gigabases (Gb) of raw reads were generated by whole-genome sequencing of the Yangtze finless porpoise, using an Illumina HiSeq 2000 platform. After filtering the low-quality and duplicated reads, we assembled a draft genome of 2.22 Gb, with contig N50 and scaffold N50 values of 46.69 kilobases (kb) and 1.71 megabases (Mb), respectively. We identified 887.63 Mb of repetitive sequences and predicted 18,479 protein-coding genes in the assembled genome. The phylogenetic tree showed a relationship between the Yangtze finless porpoise and the Yangtze River dolphin, which diverged approximately 20.84 million years ago. In comparisons with the genomes of 10 other mammals, we detected 44 species-specific gene families, 164 expanded gene families, and 313 positively selected genes in the Yangtze finless porpoise genome. The assembled genome sequence and underlying sequence data are available at the National Center for Biotechnology Information under BioProject accession number PRJNA433603. PMID:29659530

Tide-Dominated Tract (TDT) as a key sedimentary zone characterizing tide-dominated large-river delta and estuary systems

NASA Astrophysics Data System (ADS)

Saito, Y.

2017-12-01

Large rivers in continents have a characteristic of slow rise and fall in water levels during floods or the wet season due to a wide drainage basin. A gentle river gradient and large water discharge have relatively large tidal ranges at the river mouth, resulting in large backwater effects further upstream. The result of the Mekong River survey (386 riverbed sediments, river topography, CTD, and biofacies) shows that the distributary channels of the Mekong River delta in Vietnam are divided into two parts: the landward river-dominated tract (RDT) and seaward tide-dominated tract (TDT). The RDT is characterized by a highly variable and deepening trend in water depth and coarse-grained sediments with a fining trend downstream. The TDT is characterized by a shallowing trend in water depth with river-widening, smooth riverbeds, a straight shape, and heterolithic f- to vf-sand and mud alternation (tidal thythmite). The boundary of both tracts is sharply identified by sediment facies and river morphology. Sediment facies indicates that the dominant sedimentary process of bottom sediments is "bedload" in the RDT and "suspension" in the TDT. Daily tidal changes are observed through the year, while water-level changes during the flood/wet season are limited in the TDT. Saltwater intrusion is limited within the seaward part of the TDT alone ( 50 km), close to final bifurcation points. However, brackish-water biofacies is observed in the TDT mainly due to diluted brackish water and/or tolerance to the freshwater environment. These characteristics are also found in the Yangtze; the distance of the TDT/RDT boundary from the river mouth is ca. 100 km in the Mekong, and 200 km in the Yangtze. The preservation potential of sediments in a TDT is low in a progradational system, and high in abandoned channels. The early Holocene transgressive estuary system in the incised valley of the Yangtze formed during the Last Glacial Maximum was composed of 20 m-thick fine-grained heterolithic

Residence Times in Central Valley Aquifers Recharged by Dammed Rivers

NASA Astrophysics Data System (ADS)

Loustale, M.; Paukert Vankeuren, A. N.; Visser, A.

2017-12-01

Groundwater is a vital resource for California, providing between 30-60% of the state's water supply. Recent emphasis on groundwater sustainability has induced a push to characterize recharge rates and residence times for high priority aquifers, including most aquifers in California's Central Valley. Flows in almost all rivers from the western Sierra to the Central Valley are controlled by dams, altering natural flow patterns and recharge to local aquifers. In eastern Sacramento, unconfined and confined shallow aquifers (depth <300 feet) are recharged by a losing reach of the Lower American River, despite the presence of levees with slurry cut-off walls.1 Flow in the Lower American River is controlled through the operation of the Folsom and Nimbus Dams, with a minimum flow of 500 cfs. Water table elevation in wells in close proximity to the river are compared to river stage to determine the effect of river stage on groundwater recharge rates. Additionally, Tritium-3Helium dates and stable isotopes (∂18O and ∂2H) have been measured in monitoring wells 200- 2400 ft lateral distance from the river, and depths of 25 -225 feet BGS. Variation in groundwater age in the vertical and horizontal directions are used to determine groundwater flow path and velocity. These data are then used to calculate residence time of groundwater in the unconfined and confined aquifer systems for the Central Valley in eastern Sacramento. Applying groundwater age tracers can benefit future compliance metrics of the California Sustainable Groundwater Resources Act (SGMA), by quantifying river seepage rates and impacts of groundwater management on surface water resources. 1Moran et al., UCRL-TR-203258, 2004.

Heavy Metal Pollution of Lakes along the Mid-Lower Reaches of the Yangtze River in China: Intensity, Sources and Spatial Patterns

PubMed Central

Zeng, Haiao; Wu, Jinglu

2013-01-01

Lakes in the middle and lower reaches of the Yangtze River form a shallow lake group unique in the World that is becoming increasingly polluted by heavy metals. Previous studies have largely focused on individual lakes, with limited exploration of the regional pattern of heavy metal pollution of the lake group in this area. This paper explores the sources, intensity and spatial patterns of heavy metal pollution of lake sediments. A total of 45 sample lakes were selected and the concentrations of key metal elements in the sediments of each lake were measured. The cluster analysis (CA), principal component analysis (PCA) and Geo-accumulation index (Ig) analysis permitted analysis of the source and pollution intensity of the target lakes. Results suggested a notable spatial variation amongst the sample lakes. Lakes in the upper part of the lower reach of the Yangtze River surrounded by typical urban landscapes were strongly or extremely polluted, with high concentrations of Pb, Zn, Cu and Cd in their sediments. This was attributed to large amount of untreated industrial discharges and municipal sewage produced within the lake catchments. In contrast, the heavy-metal pollution of lakes in the Taihu Delta area was notably lower due to industrial restructuring and implementation of effective environmental protection measures. Lakes along the middle reach of Yangtze River surrounded by agricultural areas were unpolluted to moderately polluted by heavy metals overall. Our results suggested that lakes in the central part of China require immediate attention and efforts should be made to implement management plans to prevent further degradation of water quality in these lakes. PMID:23442559

Makran Mountain Range, Indus River Valley, Pakistan, India

NASA Technical Reports Server (NTRS)

1984-01-01

The enormous geologic pressures exerted by continental drift can be very well illustrated by the long northward curving parallel folded mountain ridges and valleys of the coastal Makran Range of Pakistan (27.0N, 66.0E). As a result of the collision of the northward bound Indian sub-continent into the Asian Continent, the east/west parallel range has been bent in a great northward arc and forming the Indus River valley at the interface of the collision.

Precursory strong-signal characteristics of the convective clouds of the Central Tibetan Plateau detected by radar echoes with respect to the evolutionary processes of an eastward-moving heavy rainstorm belt in the Yangtze River Basin

NASA Astrophysics Data System (ADS)

Zhao, Yang; Xu, Xiangde; Ruan, Zheng; Chen, Bin; Wang, Fang

2018-03-01

The integrated analysis of the data from a C-band frequency-modulated continuous-wave (C-FMCW) radar site in Naqu obtained during a rainstorm over the middle and lower reaches of the Yangtze River and the data concerning the three-dimensional structure of the circulation of the precipitation system that occurred over the lower reaches of the Yangtze River Basin during the Third Tibetan Plateau (TP) Atmospheric Experiment from August 15th to 19th, 2014, was carried out. The changes in the echo intensity at the C-FMCW radar site in Naqu were of regional indicative significance for the characteristics of the whole-layer apparent heat source Q1 in local areas and the region of the adjacent river source area, including the Yangtze River, Yellow River, and Lancang River (hereinafter referred to as the "source area of three rivers"), as well as to the vertical speeds due to the development of convection. This study indicates that the C-FMCW radar echo intensity of the plateau convection zone and the related power structures of the coupled dipole circulations in the middle layer of the atmosphere, as well as in the upper atmospheric level divergence and lower atmospheric level convergence, are important stimuli for convective clouds in this region. Furthermore, these radar data provided a physical image of the development and maintenance mechanisms of an eastward-moving heavy rainstorm belt. This study also shows that changes in the echo intensities at the C-FMCW radar site of Naqu can provide strong signals related to heavy rainstorm processes in the upper reaches of the Yangtze River.

Atmospheric nitrogen deposition in the Yangtze River basin: Spatial pattern and source attribution.

PubMed

Xu, Wen; Zhao, Yuanhong; Liu, Xuejun; Dore, Anthony J; Zhang, Lin; Liu, Lei; Cheng, Miaomiao

2018-01-01

The Yangtze River basin is one of the world's hotspots for nitrogen (N) deposition and likely plays an important role in China's riverine N output. Here we constructed a basin-scale total dissolved inorganic N (DIN) deposition (bulk plus dry) pattern based on published data at 100 observational sites between 2000 and 2014, and assessed the relative contributions of different reactive N (N r ) emission sectors to total DIN deposition using the GEOS-Chem model. Our results show a significant spatial variation in total DIN deposition across the Yangtze River basin (33.2 kg N ha -1 yr -1 on average), with the highest fluxes occurring mainly in the central basin (e.g., Sichuan, Hubei and Hunan provinces, and Chongqing municipality). This indicates that controlling N deposition should build on mitigation strategies according to local conditions, namely, implementation of stricter control of N r emissions in N deposition hotspots but moderate control in the areas with low N deposition levels. Total DIN deposition in approximately 82% of the basin area exceeded the critical load of N deposition for semi-natural ecosystems along the basin. On the basin scale, the dominant source of DIN deposition is fertilizer use (40%) relative to livestock (11%), industry (13%), power plant (9%), transportation (9%), and others (18%, which is the sum of contributions from human waste, residential activities, soil, lighting and biomass burning), suggesting that reducing NH 3 emissions from improper fertilizer (including chemical and organic fertilizer) application should be a priority in curbing N deposition. This, together with distinct spatial variations in emission sector contributions to total DIN deposition also suggest that, in addition to fertilizer, major emission sectors in different regions of the basin should be considered when developing synergistic control measures. Copyright © 2017. Published by Elsevier Ltd.

Genesis of the Datuanshan stratabound skarn Cu(-Mo) deposit, Middle-Lower Yangtze Valley, Eastern China: constraints from geology, Re-Os geochronology, mineralogy, and sulfur isotopes

NASA Astrophysics Data System (ADS)

Cao, Yi; Gao, Fuping; Du, Yangsong; Du, Yilun; Pang, Zhenshan

2017-03-01

Stratabound deposits are the most abundant and economically significant ore type in the Middle-Lower Yangtze River Valley, one of the most important metallogenic belts in China. The Datuanshan deposit is one of the largest and most representative stratabound Cu(-Mo) deposits in the Tongling district of the Middle-Lower Yangtze River metallogenic belt. All the orebodies of the Datuanshan deposit occur around Mesozoic quartz monzodiorite and are tabular or semi-tabular bodies along bedding-parallel faults within upper Permian to Lower Triassic strata. However, discordant and crosscutting relationships (e.g., the host rocks crosscut by skarn- and quartz-sulfide veins, with alteration halos around the veins) have also been found, especially along the skarn-host contact and orebody-host contact, indicating that skarnitization and mineralization postdated the deposition of the host sediments. The skarn consists mainly of prograde garnet and pyroxene and retrograde alteration assemblages of amphibole, epidote, and chlorite, as well as quartz and sulfides. Electron microprobe analyses show that the garnets and pyroxenes are grossular-andradite and hedenbergite-diopside series, respectively, and all samples plot in the field of typical skarn copper deposits worldwide. Molybdenite samples from stratiform copper ores yield Re-Os model ages of 138.2-139.9 Ma with a weighted mean age of 139.2 ± 0.9 Ma. This is reasonably consistent with the ages of the stratiform Mo ores (138.0-140.8 Ma) and genetically related quartz monzodiorite (135.2-139.3 Ma) in the Datuanshan deposit, indicating that the stratiform Cu and Mo mineralization was contemporaneous with emplacement of the quartz monzodiorite magmas in the Early Cretaceous. Fifteen δ34S values for sulfides range from -1.8 to +4.7 ‰, with a mean of 0.5 ‰, indicating that the sulfur was derived mainly from a magmatic source. Moreover, the sulfur isotope values of the ores are consistent with those of Mesozoic intermediate

Health risk assessment of heavy metals in fish and accumulation patterns in food web in the upper Yangtze River, China.

PubMed

Yi, Yujun; Tang, Caihong; Yi, Tieci; Yang, Zhifeng; Zhang, Shanghong

2017-11-01

This study aims to concern the distribution of As, Cr, Cd, Hg, Cu, Zn, Pb and Fe in surface sediment, zoobenthos and fishes, and quantify the accumulative ecological risk and human health risk of metals in river ecological system based on the field investigation in the upper Yangtze River. The results revealed high ecological risk of As, Cd, Cu, Hg, Zn and Pb in sediment. As and Cd in fish presented potential human health risk of metals by assessing integrated target hazard quotient results based on average and maximum concentrations, respectively. No detrimental health effects of heavy metals on humans were found by daily fish consumption. While, the total target hazard quotient (1.659) exceeding 1, it meant that the exposed population might experience noncarcinogenic health risks from the accumulative effect of metals. Ecological network analysis model was established to identify the transfer routes and quantify accumulative effects of metals on river ecosystem. Control analysis between compartments showed large predator fish firstly depended on the omnivorous fish. Accumulative ecological risk of metals indicated that zoobenthos had the largest metal propagation risk and compartments located at higher trophic levels were not easier affected by the external environment pollution. A potential accumulative ecological risk of heavy metal in the food web was quantified, and the noncarcinogenic health risk of fish consumption was revealed for the upper reach of the Yangtze River. Copyright © 2017 Elsevier Inc. All rights reserved.

This Glorious Mud Pile (Rocky River Valley). Revised Edition.

ERIC Educational Resources Information Center

Cabbage, Mary Ellen

This student text focuses on the social and geological history of a river basin. In addition to background information, the text includes student worksheets for 12 field trip stops in Ohio's Rocky River Valley. Material is designed to support a full-day field trip during which students work in small groups. Also included are a geological…

Modeling the Long-term Planform Evolution of Meandering Rivers in Confined Alluvial Valleys: Etsch-Adige River, NE Italy.

NASA Astrophysics Data System (ADS)

Zen, S.; Bogoni, M.; Zolezzi, G.; Lanzoni, S.; Scorpio, V.

2016-12-01

We combine the use of a morphodynamic model for river meander planform evolution with a geological dataset to investigate the influence of external confinements on the long-term evolution of a meandering river flowing in an Alpine valley. The analysis focuses on a 100 km reach of the Adige River, NE Italy, which had several sinuous/meandering sections before being extensively channelized in the 1800s. Geological surveys and historical maps revealed that many sections of the study reach impinge on the borders of the valley during its evolution. Moreover, a marked spatial heterogeneity in floodplain vertical accretion rates likely reflects preferential positions of the river channel in the floodplain. Valley confinements are represented by bedrock outcrops and by alluvial fans created by lateral tributaries, and were extracted from the geological and historical maps to build the computational domain for the meander morphodynamic model. The model predicts the long-term planform evolution of a meandering river based on a linear solution of the 2D De St Venant-Exner differential system and can manage changes in floodplain erodibility. Model applications allow to isolate the effects of valley bedrock and of alluvial fans in constraining the lateral channel migration. Modeled river channel persistence maps are compared with the available geological information. The present work allows further insights into the role of external confinements to river meander belts, which have been conducted so far mostly assuming the channel to evolve in unconfined floodplains. Future research shall incorporate model components for floodplain vertical accretion rates and for the advancement of alluvial fans occurring at the same time scale considered for meander evolution.

Improving simulations of snow water equivalent and total water storage changes over the Upper Yangtze River basin using multi-source remote sensing data

NASA Astrophysics Data System (ADS)

Han, P.; Long, D.

2017-12-01

Snow water equivalent (SWE) and total water storage (TWS) changes are important hydrological state variables over cryospheric regions, such as China's Upper Yangtze River (UYR) basin. Accurate simulation of these two state variables plays a critical role in understanding hydrological processes over this region and, in turn, benefits water resource management, hydropower development, and ecological integrity over the lower reaches of the Yangtze River, one of the largest rivers globally. In this study, an improved CREST model coupled with a snow and glacier melting module was used to simulate SWE and TWS changes over the UYR, and to quantify contributions of snow and glacier meltwater to the total runoff. Forcing, calibration, and validation data are mainly from multi-source remote sensing observations, including satellite-based precipitation estimates, passive microwave remote sensing-based SWE, and GRACE-derived TWS changes, along with streamflow measurements at the Zhimenda gauging station. Results show that multi-source remote sensing information can be extremely valuable in model forcing, calibration, and validation over the poorly gauged region. The simulated SWE and TWS changes and the observed counterparts are highly consistent, showing NSE coefficients higher than 0.8. The results also show that the contributions of snow and glacier meltwater to the total runoff are 8% and 6%, respectively, during the period 2003‒2014, which is an important source of runoff. Moreover, from this study, the TWS is found to increase at a rate of 5 mm/a ( 0.72 Gt/a) for the period 2003‒2014. The snow melting module may overestimate SWE for high precipitation events and was improved in this study. Key words: CREST model; Remote Sensing; Melting model; Source Region of the Yangtze River

[Effects of macro-jellyfish abundance dynamics on fishery resource structure in the Yangtze River estuary and its adjacent waters].

PubMed

Shan, Xiu-Juan; Zhuang, Zhi-Meng; Jin, Xian-Shi; Dai, Fang-Qun

2011-12-01

Based on the bottom trawl survey data in May 2007 and May and June 2008, this paper analyzed the effects of the abundance dynamics of macro-jellyfish on the species composition, distribution, and abundance of fishery resource in the Yangtze River estuary and its adjacent waters. From May 2007 to June 2008, the average catch per haul and the top catch per haul of macro-jellyfish increased, up to 222.2 kg x h(-1) and 1800 kg x h(-1) in June 2008, respectively. The macro-jellyfish were mainly distributed in the areas around 50 m isobath, and not beyond 100 m isobath where was the joint front of the coastal waters of East China Sea, Yangtze River runoff, and Taiwan Warm Current. The main distribution area of macro-jellyfish in June migrated northward, as compared with that in May, and the highest catches of macro-jellyfish in May 2007 and May 2008 were found in the same sampling station (122.5 degrees E, 28.5 degrees N). In the sampling stations with higher abundance of macro-jellyfish, the fishery abundance was low, and the fishery species also changed greatly, mainly composed by small-sized species (Trachurus japonicus, Harpadon nehereus, and Acropoma japonicum) and pelagic species (Psenopsis anomala, Octopus variabilis) and Trichiurus japonicus, and P. anomala accounted for 23.7% of the total catch in June 2008. Larimichthys polyactis also occupied higher proportion of the total catch in sampling stations with higher macro-jellyfish abundance, but the demersal species Lophius litulon was not found, and a few crustaceans were collected. This study showed that macro-jellyfish had definite negative effects on the fishery community structure and abundance in the Yangtze River estuary fishery ecosystem, and further, changed the energy flow patterns of the ecosystem through cascading trophic interactions. Therefore, macro-jellyfish was strongly suggested to be an independent ecological group when the corresponding fishery management measures were considered.

Using hydraulic heads, geochemistry and 3H to understand river bank infiltration; an example from the Ovens Valley, southeast Australia

NASA Astrophysics Data System (ADS)

Yu, Matthew; Cartwright, Ian

2014-05-01

Defining the relationship between the river and its river bank is important in constraining baseflow to a river and enhancing our ability in protecting water resources and riparian ecology. Hydraulic heads, geochemistry and 3H were measured in river banks along the Ovens River, southeast Australia. The Ovens River is characterised by the transition from a single channel river residing within a mountain valley to a multi-channel meandering river on broad alluvial plains in the lower catchment. The 3H concentrations of most near-river groundwater (less than 10 m from river channel) and bank water (10 - 30 m from the river channel) in the valley range between 1.93 and 2.52 TU. They are similar to those of the river, which are between 2.37 and 2.24 TU. These groundwater also have a Na/Cl ratio of 2.7 - 4.7 and are close to the river Na/Cl ratios. These similarities suggest that most river banks in the valley are recharged by the river. The hydraulic heads and EC values indicate that some of these river banks are recharged throughout the year, while others are only recharged during high flow events. Some near-river groundwater and bank water in the valley have a much lower 3H concentration, ranging from 0.97 to 1.27 TU. They also have a lower Na/Cl ratio of 1.6 - 3.1. These differences imply that some of the river banks in the valley are rarely recharged by the river. The lack of infiltration is supported by the constant head gradient toward the river and the constant EC values in these river banks. The river banks with bank infiltration are located in the first few hundred kilometres in the valley and in the middle catchment where the valley is broaden. In the first few hundred kilometres in the valley, it has a relatively flat landscape and does not allow a high regional water table to form. The river thus is always above the water table and recharges the river banks and the valley aquifers. In the broader valley, the relatively low lateral hydraulic gradient is

Climatic and morphological controls on post-glacial lake and river valley evolution in the Weichselian belt - an example from the Wda valley, Northern Poland

NASA Astrophysics Data System (ADS)

Kramkowski, M. A.; Błaszkiewicz, M.; Piotrowski, J. A.; Brauer, A.; Gierszewski, P.; Kordowski, J.; Lamparski, P.; Lorenz, S.; Noryśkiewicz, A. M.; Ott, F.; Slowinski, M. M.; Tyszkowski, S.

2014-12-01

The River Wda valley is a classical example of a polygenetic valley, consisting of former lake basins joined by erosive gap sections. In its middle section, which was the subject of our research, a fragment of an abandoned Lateglacial river valley is preserved, which is unique for the Weichselian moraine belt in the Central European Lowlands. The analysis of the relationship between the lacustrine and fluvial sediments and landforms enabled the authors to report many evolutionary connections between the initial period of the river system formation and the emergence of lakes during the Weichselian Lateglacial. The surface drainage essentially determined the progress of melting of dead ice blocks buried in the glacial depressions, which finally led to lake formation there. Most of the lake basins in the study area were formed during the Bølling-Allerød period. However, one section of the subglacial channel was not exposed to the thermokarst conditions and was therefore preserved with dead ice blocks throughout the entire Lateglacial. The dead ice decay at the beginning of the Holocene, as well as the emergence of another lake, created a lower base level of erosion in the close vicinity of the abandoned valley and induced a change of the river's course. Both fluvial and lacustrine deposits and landforms distributed in the central section of the River Wda valley indicate two processes, which proceeded simultaneously: (1) emergence of fluvially joined lake basins within a glacial channel, (2) degradation of the river bed in the gap sections interfering between the lakes. The processes described for the central section of the River Wda channel indicate a very dynamic river valley development during the Weichselian Lateglacial and the early Holocene. The valley formation was tightly interwoven with the morphogenesis of the primary basins within the valley, mainly with the melting of the buried blocks of dead ice and the development of lakes. This study is a contribution

Association analysis between spatiotemporal variation of vegetation greenness and precipitation/temperature in the Yangtze River Basin (China).

PubMed

Cui, Lifang; Wang, Lunche; Singh, Ramesh P; Lai, Zhongping; Jiang, Liangliang; Yao, Rui

2018-05-23

The variation in vegetation greenness provides good understanding of the sustainable management and monitoring of land surface ecosystems. The present paper discusses the spatial-temporal changes in vegetation and controlling factors in the Yangtze River Basin (YRB) using Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) for the period 2001-2013. Theil-Sen Median trend analysis, Pearson correlation coefficients, and residual analysis have been used, which shows decreasing trend of the annual mean NDVI over the whole YRB. Spatially, the regions with significant decreasing trends were mainly located in parts of central YRB, and pronounced increasing trends were observed in parts of the eastern and western YRB. The mean NDVI during spring and summer seasons increased, while it decreased during autumn and winter seasons. The seasonal mean NDVI shows spatial heterogeneity due to the vegetation types. The correlation analysis shows a positive relation between NDVI and temperature over most of the YRB, whereas NDVI and precipitation show a negative correlation. The residual analysis shows an increase in NDVI in parts of eastern and western YRB and the decrease in NDVI in the small part of Yangtze River Delta (YRD) and the mid-western YRB due to human activities. In general, climate factors were the principal drivers of NDVI variation in YRB in recent years.

Community Survey Results for Rappahannock River Valley National Wildlife Refuge: Completion Report

USGS Publications Warehouse

Sexton, Natalie R.; Stewart, Susan C.; Koontz, Lynne

2008-01-01

This report provides a summary of results for the survey of residents of communities adjacent to Rappahannock River Valley NWR conducted from the spring through the summer in 2006. This research was commissioned by the Northeast Region of the U.S. Fish and Wildlife Service in support of the Rappahannock River Valley NWR CCP and conducted by the Policy Analysis and Science Assistance Branch (PASA) of the U.S. Geological Survey/Fort Collins Science Center.

Water resources of the Humboldt River Valley near Winnemucca, Nevada

USGS Publications Warehouse

Cohen, Philip M.

1965-01-01

This report, resulting from studies made by the U.S. Geological Survey as part of the interagency Humboldt River Research Project, describes the qualitative and quantitative relations among the components of the hydrologic system in the Winnemucca Reach of the Humboldt River valley. The area studied includes the segment of the Humboldt River valley between the Comus and Rose Creek gaging stations. It is almost entirely in Humboldt County in north-central Nevada, and is about 200 miles downstream from the headwaters of the Humboldt River. Agriculture is the major economic activity in the area. Inasmuch as the valley lowlands receive an average of about 8 inches of precipitation per year and because the rate of evaporation from free-water surfaces is about six times the average annual precipitation, all crops in the area (largely forage crops) are irrigated. About 85 percent of the cultivated land is irrigated with Humboldt River water; the remainder is irrigated from about 20 irrigation wells. The consolidated rocks of the uplifted fault-block mountains are largely barriers to the movement of ground water and form ground-water and surface-water divides. Unconsolidated deposits of late Tertiary and Quaternary age underlie the valley lowlands to a maximum depth of about 5,000 feet. These deposits are in hydraulic continuity with the Humboldt River and store and transmit most of the economically recoverable ground water. Included in the valley fill is a highly permeable sand and gravel deposit having a maximum thickness of about 90-100 feet; it underlies the flood plain and bordering terraces throughout most of the project area. This deposit is almost completely saturated and contains about 500,000 acre-feet of ground water in storage. The Humboldt River is the source of 90-95 percent of the surface-water inflow to the area. In water years 1949-62 the average annual streamflow at the Comus gaging station at the upstream margin of the area was 172,100 acre-feet; outflow

Fishes in paleochannels of the Lower Mississippi River alluvial valley: A national treasure

USGS Publications Warehouse

Miranda, Leandro E.

2016-01-01

Fluvial geomorphology of the alluvial valley of the Lower Mississippi River reveals a fascinating history. A prominent occupant of the valley was the Ohio River, estimated to have flowed 25,000 years ago over western Tennessee and Mississippi to join the Mississippi River north of Baton Rouge, Louisiana, 750–800 km south of the present confluence. Over time, shifts in the Mississippi and Ohio rivers toward their contemporary positions have left a legacy of abandoned paleochannels supportive of unique fish assemblages. Relative to channels abandoned in the last 500 years, paleochannels exhibit harsher environmental conditions characteristic of hypereutrophic lakes and support tolerant fish assemblages. Considering their ecological, geological, and historical importance, coupled with their primordial scenery, the hundreds of paleochannels in the valley represent a national treasure. Altogether, these waterscapes are endangered by human activities and would benefit from the conservation attention afforded to our national parks and wildlife refuges.

27 CFR 9.111 - Kanawha River Valley.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Kanawha River Valley. 9.111 Section 9.111 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Addison, Ohio—W. Va., dated 1960; (2) Gallipolis, Ohio—W. Va., dated 1958; (3) Apple Grove, Ohio—W. Va...

27 CFR 9.111 - Kanawha River Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Kanawha River Valley. 9.111 Section 9.111 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Addison, Ohio—W. Va., dated 1960; (2) Gallipolis, Ohio—W. Va., dated 1958; (3) Apple Grove, Ohio—W. Va...

27 CFR 9.111 - Kanawha River Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Kanawha River Valley. 9.111 Section 9.111 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Addison, Ohio—W. Va., dated 1960; (2) Gallipolis, Ohio—W. Va., dated 1958; (3) Apple Grove, Ohio—W. Va...

27 CFR 9.111 - Kanawha River Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Kanawha River Valley. 9.111 Section 9.111 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Addison, Ohio—W. Va., dated 1960; (2) Gallipolis, Ohio—W. Va., dated 1958; (3) Apple Grove, Ohio—W. Va...

27 CFR 9.111 - Kanawha River Valley.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Kanawha River Valley. 9.111 Section 9.111 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Addison, Ohio—W. Va., dated 1960; (2) Gallipolis, Ohio—W. Va., dated 1958; (3) Apple Grove, Ohio—W. Va...

Mid-Holocene hydrology change in the south Taihu area of the Yangtze delta plain, China, and its relationship to the development of Neolithic cultures

NASA Astrophysics Data System (ADS)

Chen, T.; Ryves, D.; Wang, Z.; Lewis, J.

2017-12-01

During the middle Holocene, the hydrological environments in the Taihu Plain, Yangtze Delta, China, varied tremendously under the influence of sea-level and climate change. Simultaneously, several Neolithic cultures, such as, the Majiabang, Songze, and Liangzhu culture, developed in this region. Basing on AMS14C dating, diatom identification, measurements of C-N elements and their stable isotopes of sediments from core DTX4 and DTX10, obtained in the East Tiaoxi Plain, south Taihu plain, we discussed the influence of hydrology changes on the development of Neolithic cultures. The results revealed that the East Tiaoxi River plain was in an estuary (the Palaeo-Taihu Estuary) condition at 7500 cal. yr BP, undergoing elevated in-fill in response to rapid sea-level rise. After 7500 cal. yr BP, low salinity conditions occurred, likely influenced by the Yangtze freshwater evidenced by constant occurrence of Aulacoseira granulata, which implied Yangtze runoff discharged along the channel of Palaeo-incised Taihu valley into the Hangzhou Bay during the middle Holocene. Sea-water penetration interrupted after 7000 cal. yr BP caused by an abrupt sea-level rise. During 6500-5600 cal. yr BP, sea-water retreated gradually, corresponding to the infilling of Palaeo-Taihu Estuary. Combing records from previously studied cores in the Taihu plain, stable freshwater condition (or dry land) established in most area of the Taihu plain after 5600 cal. yr BP due to the closure of the Palaeo-Taihu Estuary. We speculate that the low-salinity marsh started at about 7500-7000 cal. yr BP probably attracted the early Majiabang people to live around the Palaeo-Taihu Estuary. The sea water penetration between 7000-6500 cal. yr BP matches the left of the late Majiabang and the early-middle Songze people lived in the east of the Palaeo-Taihu Estuary, to the north and east of the Taihu Plain. The context of stable freshwater condition (or dry land) in the East Tiaoxi River plain promoted the

Seasonal variation in drifting eggs and larvae in the upper Yangtze, China.

PubMed

Jiang, Wei; Liu, Huan-Zhang; Duan, Zhong-Hua; Cao, Wen-Xuan

2010-05-01

From 5 March to 25 July 2008, ichthyoplankton drifting into the Three Gorges Reservoir from the upper reaches of the Yangtze River were sampled daily to investigate the species composition, abundance, and seasonal variation in early-stage fishes in this area. Twenty-eight species belonging to five orders and 17 families or subfamilies were identified by analyzing fish eggs and larvae, and a total of 14.16 billion individuals were estimated drifting through the sampling section during the investigation. Among the ichthyoplankton sampled, species in Cultrinae, Cobitidae, Gobioninae and Gobiidae, along with the common carp (Cyprinus carpio Linnaeus), comprised 89.6% of the total amount. Six peaks of drift density were identified during the sampling period, and a significant correlation was found between drift density with water discharge. The dominant species were different in each drift peak, indicating different spawning times for the major species. The total amount of the four major Chinese carps that drifted through the sampling section was estimated as 0.88 billion, indicating an increase in the population sizes of these species in the upper reaches of the Yangtze River after construction of the Three Gorges Dam. Actually, these reaches have become the largest spawning area for the four major Chinese carps in the Yangtze River. The large total amount of eggs and larvae drifting through this section demonstrated that the upper reaches of the Yangtze River provided important spawning sites for many fish species, and that conservation of this area should be of great concern.

Land Capability Potential Index (LCPI) and geodatabase for the Lower Missouri River Valley

USGS Publications Warehouse

Chojnacki, Kimberly A.; Struckhoff, Matthew A.; Jacobson, Robert B.

2012-01-01

The Land Capacity Potential Index (LCPI) is a coarse-scale index intended to delineate broad land-capability classes in the Lower Missouri River valley bottom from the Gavins Point Dam near Yankton, South Dakota to the mouth of the Missouri River near St. Louis, Missouri (river miles 811–0). The LCPI provides a systematic index of wetness potential and soil moisture-retention potential of the valley-bottom lands by combining the interactions among water-surface elevations, land-surface elevations, and the inherent moisture-retention capability of soils. A nine-class wetness index was generated by intersecting a digital elevation model for the valley bottom with sloping water-surface elevation planes derived from eight modeled discharges. The flow-recurrence index was then intersected with eight soil-drainage classes assigned to soils units in the digital Soil Survey Geographic (SSURGO) Database (Soil Survey Staff, 2010) to create a 72-class index of potential flow-recurrence and moisture-retention capability of Missouri River valley-bottom lands. The LCPI integrates the fundamental abiotic factors that determine long-term suitability of land for various uses, particularly those relating to vegetative communities and their associated values. Therefore, the LCPI provides a mechanism allowing planners, land managers, landowners, and other stakeholders to assess land-use capability based on the physical properties of the land, in order to guide future land-management decisions. This report documents data compilation for the LCPI in a revised and expanded, 72-class version for the Lower Missouri River valley bottom, and inclusion of additional soil attributes to allow users flexibility in exploring land capabilities.

Polyfluoroalkyl substance exposure in the Mid-Ohio River Valley, 1991-2012.

PubMed

Herrick, Robert L; Buckholz, Jeanette; Biro, Frank M; Calafat, Antonia M; Ye, Xiaoyun; Xie, Changchun; Pinney, Susan M

2017-09-01

Industrial discharges of perfluorooctanoic acid (PFOA) to the Ohio River, contaminating water systems near Parkersburg, WV, were previously associated with nearby residents' serum PFOA concentrations above US general population medians. Ohio River PFOA concentrations downstream are elevated, suggesting Mid-Ohio River Valley residents are exposed through drinking water. Quantify PFOA and 10 other per- and polyfluoroalkyl substances (PFAS) in Mid-Ohio River Valley resident sera collected between 1991 and 2013 and determine whether the Ohio River and Ohio River Aquifer are exposure sources. We measured eleven PFAS in 1608 sera from 931 participants. Serum PFOA concentration and water source associations were assessed using linear mixed-effects models. We estimated between-sample serum PFOA using one-compartment pharmacokinetics for participants with multiple samples. In serum samples collected as early as 1991, PFOA (median = 7.6 ng/mL) was detected in 99.9% of sera; 47% had concentrations greater than US population 95th percentiles. Five other PFAS were detected in greater than 82% of samples; median other PFAS concentrations were similar to the US general population. Serum PFOA was significantly associated with water source, sampling year, age at sampling, tap water consumption, pregnancy, gravidity and breastfeeding. Serum PFOA was 40-60% lower with granular activated carbon (GAC) use. Repeated measurements and pharmacokinetics suggest serum PFOA peaked 2000-2006 for participants using water without GAC treatment; where GAC was used, serum PFOA concentrations decreased from 1991 to 2012. Mid-Ohio River Valley residents appear to have PFOA, but not other PFAS, serum concentrations above US population levels. Drinking water from the Ohio River and Ohio River Aquifer, primarily contaminated by industrial discharges 209-666 km upstream, is likely the primary exposure source. GAC treatment of drinking water mitigates, but does not eliminate, PFOA exposure. Copyright

[Effect of water conservancy schistosomiasis control projects combined with molluscicide to control Oncomelania hupensis snails in rivers connecting with Yangtze River in Pukou District, Nanjing City].

PubMed

Qiang, Zhou; Li-Xin, Wan; De-Rong, Hang; Qi-Hui, You; Jun, You; Yu-Lin, Zhang; Zhao-Feng, Zhu; Yi-Xin, Huang

2017-12-07

To evaluate the effect of the water conservancy schistosomiasis control projects combined with molluscicide to control Oncomelania hupensis snails in the rivers connecting with the Yangtze River. The water conservancy schistosomiasis control projects of Zhujiashan River, Qili River and Gaowang River were chosen as the study objects in Pukou District, Nanjing City. The data review method and field investigation were used to evaluate the effect of the water conservancy schistosomiasis control projects combined with molluscicide to control O. hupensis snails. After the projects of the water level control and concrete slope protection and mollusciciding were implemented, the snails in the project river sections were completely eliminated. The snail diffusion did not happen in the inland irrigation area too. In the outside of the river beach, though the snails still existed, the snail densities plunged below 1.0 snail per 1.0 m 2 . The comprehensive measures of the combination of water level control, concrete slope protection and mollusciciding can effectively control and eliminate the snails, and prevent the snails from spreading.

Notes on the geology of Green River Valley between Green River, Wyoming, and Green River, Utah

USGS Publications Warehouse

Reeside, J.B.

1925-01-01

During July, August, and part of September, 1922, I had the privilege of accompanying a party sent out jointly by the Utah Power & Light Co. and the United States Geological Survey to gather such data as were still needed to complete a study of the power resources of Green River between Green River, Wyo., and Green River, Utah. The chief deficiency to be supplied was a continuous topographic map of the valley in sufficient detail to permit calculation of the storage capacity of any reservoir site that might be used, the stream gradient, and similar features. Maps on a satisfactory scale of a number of isolated stretches of the river had already been made by public or private agencies, and it was necessary to verify them and connect them on a uniform datum. Inasmuch as it was deemed unlikely that a dam higher than 300 feet would be constructed anywhere on the part of the river to be examined, a plane 300 feet above the water surface was made the upper limit of mapping. Over such parts of the valley as had been mapped already the progress of the party was naturally very rapid, and even where no mapping had previously been done, the 300-foot limit set upon the work and the usual narrowness of the valley combined to reduce the extent of the area to be mapped, so that the speed maintained was relatively high. Under this condition of rapid movement it was seldom possible to make more than the most cursory examination of the rocks, though occasionally circumstances permitted more or less detailed observation. The notes here recorded are therefore mostly of a rather generalized character, but as they pertain in part to localities that are difficult of access and not often visited by geologists, and that are at the same time classic in the history of American geology, I venture to to record them for whatever value they may have to other geologists.

Spatial-Temporal Variations of Chlorophyll-a in the Adjacent Sea Area of the Yangtze River Estuary Influenced by Yangtze River Discharge.

PubMed

Wang, Ying; Jiang, Hong; Jin, Jiaxin; Zhang, Xiuying; Lu, Xuehe; Wang, Yueqi

2015-05-20

Carrying abundant nutrition, terrigenous freshwater has a great impact on the spatial and temporal heterogeneity of phytoplankton in coastal waters. The present study analyzed the spatial-temporal variations of Chlorophyll-a (Chl-a) concentration under the influence of discharge from the Yangtze River, based on remotely sensed Chl-a concentrations. The study area was initially zoned to quantitatively investigate the spatial variation patterns of Chl-a. Then, the temporal variation of Chl-a in each zone was simulated by a sinusoidal curve model. The results showed that in the inshore waters, the terrigenous discharge was the predominant driving force determining the pattern of Chl-a, which brings the risk of red tide disasters; while in the open sea areas, Chl-a was mainly affected by meteorological factors. Furthermore, a diversity of spatial and temporal variations of Chl-a existed based on the degree of influences from discharge. The diluted water extended from inshore to the east of Jeju Island. This process affected the Chl-a concentration flowing through the area, and had a potential impact on the marine environment. The Chl-a from September to November showed an obvious response to the discharge from July to September with a lag of 1 to 2 months.

Spatial-Temporal Variations of Chlorophyll-a in the Adjacent Sea Area of the Yangtze River Estuary Influenced by Yangtze River Discharge

PubMed Central

Wang, Ying; Jiang, Hong; Jin, Jiaxin; Zhang, Xiuying; Lu, Xuehe; Wang, Yueqi

2015-01-01

Carrying abundant nutrition, terrigenous freshwater has a great impact on the spatial and temporal heterogeneity of phytoplankton in coastal waters. The present study analyzed the spatial-temporal variations of Chlorophyll-a (Chl-a) concentration under the influence of discharge from the Yangtze River, based on remotely sensed Chl-a concentrations. The study area was initially zoned to quantitatively investigate the spatial variation patterns of Chl-a. Then, the temporal variation of Chl-a in each zone was simulated by a sinusoidal curve model. The results showed that in the inshore waters, the terrigenous discharge was the predominant driving force determining the pattern of Chl-a, which brings the risk of red tide disasters; while in the open sea areas, Chl-a was mainly affected by meteorological factors. Furthermore, a diversity of spatial and temporal variations of Chl-a existed based on the degree of influences from discharge. The diluted water extended from inshore to the east of Jeju Island. This process affected the Chl-a concentration flowing through the area, and had a potential impact on the marine environment. The Chl-a from September to November showed an obvious response to the discharge from July to September with a lag of 1 to 2 months. PMID:26006121

Recycling of Pleistocene valley fills dominates 125 ka of sediment flux, upper Indus River

NASA Astrophysics Data System (ADS)

Munack, Henry; Blöthe, Jan Henrik; Fülöp, Réka-Hajnalka; Codilean, Alexandru T.; Fink, David; Korup, Oliver

2016-04-01

Rivers draining the semiarid Transhimalayan Ranges along the western Tibetan Plateau margin underwent alternating phases of massive valley infill and incision in Pleistocene times. The imprints of these cut-and-fill cycles on long-term sediment fluxes have remained largely elusive. We investigate the timing and geomorphic consequences of headward incision of the Zanskar River, which taps the vast More Plains valley fill that currently impedes drainage of the endorheic high-altitude basins of Tso Kar and Tso Moriri. In situ 10Be exposure dating and topographic analyses indicate that a phase of valley infill gave way to net dissection of the >250-m thick sedimentary stacks ˜125 ka ago, i.e. during the last interglacial (MIS 5e). Rivers eroded >14.7 km3 of sediment from the Zanskar headwaters since then, fashioning specific sediment yields that surpass 10Be-derived denudation rates from neighbouring catchments by factors of two to ten. We conclude that recycling of Pleistocene valley fills has provided Transhimalayan headwater rivers with more sediment than bedrock denudation, at least since the beginning of the last glacial cycle. This protracted liberation of sediment stored in thick valley fills could bias rate estimates of current sediment loads and long-term bedrock denudation.

[Distributions and air-sea fluxes of dissolved nitrous oxide in the Yangtze River estuary and its adjacent marine area in spring and summer].

PubMed

Wang, Lan; Zhang, Gui-ling; Sun, Ming-shuang; Ren, Jing-ling

2014-12-01

Distributions and air-sea fluxes of nitrous oxide (N2O) in the seawaters of the Yangtze River estuary and its adjacent marine area were investigated during two cruises in March and July 2012. Dissolved N2O concentrations in surface waters ranged from 9.34 to 49.08 nmol x L(-1) with an average of (13.27 ± 6.40) nmol x L(-1) in spring and ranged from 7.27 to 27.81 nmol x L(-1) with an average of (10.62 ± 5.03) nmol x L(-1) in summer. There was no obvious difference between surface and bottom N2O concentrations. N2O concentrations in both surface and bottom waters decreased along the freshwater plume from the river mouth to the open sea. High values of dissolved N2O were found in turbidity maximum zone, which suggests that maximal turbidity enhances nitrification. Temperature had dual effects on dissolved N2O concentrations. N2O saturations in surface waters ranged from 86.9% to 351.3% with an average of (111.5 ± 41.4)% in spring and ranged from 111.7% to 396.0% with an average of (155.9 ± 68.4)% in summer. N2O were over-saturated at most stations. The sea-to-air fluxes of N2O were estimated to be (3.2 ± 10.9), (5.5 ± 19.3) and (12.2 ±52.3) μmol x (m2 x d)(-1) in spring and (7.3 ± 12.4), (12.7 ± 20.4) and (20.4 ± 35.9) μmol x (m2 x d)(-1) in summer using the LM86, W92 and RC01 relationships, respectively. The annual emissions of N2O from the Yangtze River estuary and its adjacent marine area were estimated to be 0.6 x 10(-2) Tg x a(-1) (LM86), 1.1 x 10(-2) Tg x a(-1) (W92) and 2.0 x 10(-2) Tg x a(-1) (RC01). Although the area of the Yangtze River estuary and its adjacent marine area only accounts for 0.02% of the total area of the world's oceans, their emission of N2O accounts for 0.06% of global oceanic N2O emission, indicating that the Yangtze River estuary and its adjacent marine area is an active area to produce and emit N2O.

Perfluoroalkyl and polyfluoroalkyl substances in the lower atmosphere and surface waters of the Chinese Bohai Sea, Yellow Sea, and Yangtze River estuary.

PubMed

Zhao, Zhen; Tang, Jianhui; Mi, Lijie; Tian, Chongguo; Zhong, Guangcai; Zhang, Gan; Wang, Shaorui; Li, Qilu; Ebinghaus, Ralf; Xie, Zhiyong; Sun, Hongwen

2017-12-01

Polyfluoroalkyl and perfluoroalkyl substances (PFASs), in the forms of neutral polyfluoroalkyl substances in the gas phase of air and ionic perfluoroalkyl substances in the dissolved phase of surface water, were investigated during a sampling campaign in the Bohai Sea, Yellow Sea, and Yangtze River estuary in May 2012. In the gas phase, the concentrations of neutral ∑PFASs were within the range of 76-551pg/m 3 . Higher concentrations were observed in the South Yellow Sea. 8:2 fluorotelomer alcohol (FTOH) was the predominant compound as it accounted for 92%-95% of neutral ∑PFASs in all air samples. Air mass backward trajectory analysis indicated that neutral ∑PFASs came mainly from the coast of the Yellow Sea, including the Shandong, Jiangsu, and Zhejiang provinces of China, and the coastal region of South Korea. The fluxes of gas phase dry deposition were simulated for neutral PFASs, and neutral ∑PFASs fluxes varied from 0.37 to 2.3pg/m 2 /s. In the dissolved phase of the surface water, concentrations of ionic ∑PFASs ranged from 1.6 to 118ng/L, with the Bohai Sea exhibiting higher concentrations than both the Yellow Sea and the Yangtze River estuary. Perfluorooctanoic acid (PFOA) was the predominant compound accounting for 51%-90% of the ionic ∑PFAS concentrations. Releases from industrial and domestic activities as well as the semiclosed geographical conditions increased the level of ionic ∑PFASs in the Bohai Sea. The spatial distributions of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) were different significantly. The Laizhou Bay was the major source region of PFCAs and the Yangtze River estuary was the major source of PFSAs. Copyright © 2017 Elsevier B.V. All rights reserved.

Raptor ecology of Raft River Valley, Idaho

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

Thurow, T.L.; White, C.M.; Howard, R.P.

1980-09-01

Raptor data were gathered in the 988-km/sup 2/ Raft River Valley in southcentral Idaho while conducting a tolerance study on the nesting Ferruginous Hawk (Buteo regalis) near the Department of Energy's Raft River Geothermal Site. Prior research from 1972 to 1977 on the nesting activity of the Ferruginous Hawk population provided a historical information base. These data are combined with new Ferruginous Hawk data collected between 1978 and 1980 to give a continuous 9-year breeding survey. Information on the distribution, density, and production of the other raptor species found in the study area during 1978 and 1979 is also provided.

Biological thresholds of nitrogen and phosphorus in a typical urban river system of the Yangtz delta, China.

PubMed

Liang, Xinqiang; Zhu, Sirui; Ye, Rongzhong; Guo, Ru; Zhu, Chunyan; Fu, Chaodong; Tian, Guangming; Chen, Yingxu

2014-09-01

River health and associated risks are fundamentally dependent on the levels of the primary productivities, i.e., sestonic and benthic chlorophyll-a. We selected a typical urban river system of the Yangtz delta to investigate nutrient and non-nutrient responses of chlorophyll-a contents and to determine biological thresholds of N and P. Results showed the mean contents of sestonic and benthic chlorophyll-a across all sampling points reached 10.2 μg L(-1) and 149.3 mg m(-2). The self-organized mapping analysis suggested both chlorophyll-a contents clearly responded to measurements of N, P, and water temperature. Based on the chlorophyll-a criteria for fresh water and measured variables, we recommend the biological thresholds of N and P for our river system be set at 2.4 mg N L(-1) and 0.2 mg P L(-1), and these be used as initial nutrient reference values for local river managers to implement appropriate strategies to alleviate nutrient loads and trophic status. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of the operation of cascade reservoirs in upper Yangtze River on hydrological variability of the mainstream

NASA Astrophysics Data System (ADS)

Changjiang, Xu; Dongdong, Zhang

2018-06-01

As the impacts by climate changes and human activities are intensified, variability may occur in river's annual runoff as well as flood and low water characteristics. In order to understand the characteristics of variability in hydrological series, diagnosis and identification must be conducted specific to the variability of hydrological series, i.e., whether there was variability and where the variability began to occur. In this paper, the mainstream of Yangtze River was taken as the object of study. A model was established to simulate the impounding and operation of upstream cascade reservoirs so as to obtain the runoff of downstream hydrological control stations after the regulation by upstream reservoirs in different level years. The Range of Variability Approach was utilized to analyze the impact of the operation of upstream reservoirs on the variability of downstream. The results indicated that the overall hydrologic alterations of Yichang hydrological station in 2010 level year, 2015 level year and the forward level year were 68.4, 72.5 and 74.3 % respectively, belonging to high alteration in all three level years. The runoff series of mainstream hydrological stations presented variability in different degrees, where the runoff series of the four hydrological stations including Xiangjiaba, Gaochang and Wulong belonged to high alteration in the three level years; and the runoff series of Beibei hydrological station in 2010 level year belonged to medium alteration, and high alteration in 2015 level year and the forward level year. The study on the impact of the operation of cascade reservoirs in Upper Yangtze River on hydrological variability of the mainstream had important practical significance on the sustainable utilization of water resources, disaster prevention and mitigation, safe and efficient operation and management of water conservancy projects and stable development of the economic society.

Sedimentary Facies and Stratigraphy of the Changjiang (Yangtze River) Delta

NASA Astrophysics Data System (ADS)

Dalrymple, R. W.; Zhang, X.; Lin, C. M.

2017-12-01

A disproportionate number of the world's largest deltas are tide-dominated or strongly tide-influenced, in part because the low gradient of these rivers allows the tide to penetrate far inland, generating strong tidal currents at the river mouth. These deltas also tend to be mud-dominated because a significant fraction of the bedload is trapped farther inland. Despite their great importance as sediment depo-centers, as analogues for ancient sedimentary successions, and as areas of intense human occupation, they are the most poorly understood coastal system. The Changjiang (Yangtze River), the 4th largest river in the world in terms of sediment discharge, is one such tide-dominated system, with a mean tidal range of 2.7 m and tidal-current speeds of 1 m/s at its mouth. It shows a fairly typical series of low-relief channels and bars in the mouth-bar area and passes seaward and down-drift into a coastal mud belt that extends 800 km to the south of the river mouth. The deposits from both the transgressive-phase and modern delta are all dominated by mud, except for the fluvial-channel deposits that are clean sand. Channel-floor deposits in areas with appreciable tidal influence contain abundant fluid-mud layers (1-3 cm thick), intercalated with relatively coarse sand; such mud layers show evidence of tidal cyclicity. The overlying tidal-bar deposits commonly become sandier upward because of the upward loss of fluid-mud layers. The tidal channels and bars that characterize the mouth-bar and delta-front area are dominated by randomly organized structureless mud layers, 5-30 cm thick, that are interpreted to be storm-generated fluid-mud deposits. These mud layers become less abundant upward, generating upward-sanding successions. These facies are very similar to those seen in the Amazon and Fly River deltas, suggesting that this is a common motif, and indicating the importance of fluid mud in the dynamics of such systems. Facies proximality can be determined by careful

Exhumation history of the Anqing Orefield in the Lower Yangtze River Metallogenic Belt: Evidence from apatite fission-track thermochronology

NASA Astrophysics Data System (ADS)

Li, X.; Yang, X.

2017-12-01

The Lower Yangtze River Metallogenic Belt (LYRMB) is one of the most important Cu-Au-Fe polymetallic belts in China. These deposits along the Yangtze River region have been related to the Yanshanian intrusive rocks in the Mesozoic. The Anqing orefield is located in the northwestern Anqing, southwestern Anhui Province, eastern China, along the Lower Yangtze River Belt. Here, we report new apatite fission-track (AFT) thermochronology of the granitoids ( 130 Ma for zircon U-Pb age) associated with the Anqing orefields to reveal the exhumation history of the Anqing orefields in LYRMB, eastern China. AFT ages from 54.4±2.1 to 63.9±3.4 Ma with mean measured track lengths between 12.4±1.8 and 13.1±1.4 μm, were obtained for the granitoids sampled from the ore fields in the Anqing orefield, and AFT age of 36.3±1.3 Ma with mean track length of 12.3±2.3μm for the granitoids adjacent to the south Tan-Lu fault. A long, slow exhumation ( 60-15 Ma), and a short, rapid tectonic exhumation (15-0 Ma) have been identified in the study region based on the AFT data and modeling results for the samples from the ore fields. The results show that the granitoids underwent roughly similar cooling, and inferred exhumation pattern. Assuming a steady-state paleogeothermal gradient of 35ºC/km founded on geological setting, the exhumations of 570 m and 1140 m, were achieved in the Anqing orefield, during 60-15 Ma and 15-0 Ma, respectively. Further, the AFT age of the granitoids adjacent to the south Tan-Lu fault is less than the AFT ages of the granitoids associated with the ore fields, possibly owing to the activation of the Tan-Lu fault in the Cenozoic. The exhumation history of the Anqing orefields may be closely response to the Pacific Plate subduction in the Cenozoic, which could be implications for the preservation potential of ore bodies in the Anqing orefield. This work is supported by the National Natural Science Foundation of China (41372227), and the DREAM project of MOST

New Insights Into Valley Formation and Preservation: Geophysical Imaging of the Offshore Trinity River Paleovalley

NASA Astrophysics Data System (ADS)

Speed, C. M.; Swartz, J. M.; Gulick, S. P. S.; Goff, J.

2017-12-01

The Trinity River paleovalley is an offshore stratigraphic structure located on the inner continental shelf of the Gulf of Mexico offshore Galveston, Texas. Its formation is linked to the paleo-Trinity system as it existed across the continental shelf during the last glacial period. Newly acquired high-resolution geophysical data have imaged more complexity to the valley morphology and shelf stratigraphy than was previously captured. Significantly, the paleo-Trinity River valley appears to change in the degree of confinement and relief relative to the surrounding strata. Proximal to the modern shoreline, the interpreted time-transgressive erosive surface formed by the paleo-river system is broad and rugose with no single valley, but just 5 km farther offshore the system appears to become confined to a 10 km wide valley structure before again becoming unconfined once again 30 km offshore. Fluvial stratigraphy in this region has a similar degree of complexity in morphology and preservation. A dense geophysical survey of several hundred km is planned for Fall 2017, which will provide unprecedented imaging of the paleovalley morphology and associated stratigraphy. Our analysis leverages robust chirp processing techniques that allow for imaging of strata on the decimeter scale. We will integrate our geophysical results with a wide array of both newly collected and previously published sediment cores. This approach will allow us to address several key questions regarding incised valley formation and preservation on glacial-interglacial timescales including: to what extent do paleo-rivers remain confined within a single broad valley structure, what is the fluvial systems response to transgression, and what stratigraphy is created and preserved at the transition from fluvial to estuarine environments? Our work illustrates that traditional models of incised valley formation and subsequent infilling potentially fail to capture the full breadth of dynamics of past river

Integrated magnetostratigraphy and lithostratigraphy of five cores in Yangtze delta, China : significance of sedimentary evolution

NASA Astrophysics Data System (ADS)

Peng, Jie; Yang, XiaoQiang; Qiang, XiaoKe; Liu, YeBo; Zhou, QiXian

2017-04-01

The sedimentary history and characteristics of the Yangtze delta help us understand the tectonic evolution and geological formation process in the Eastern coastal area of China since the Cenozoic Era. Previous chronology of sediments in this area are not detailed or precise. Furthermore, when the delta area reached the maximum is still debatable. Palaeomagnetic polarity reversal and excursions, AMS14C dating, optically stimulated luminescence (OSL) dating, and the hard clay marker layer analysis were integrated to establish the chronostratigraphic framework of five drilling cores from the south Yangtze delta. Results from the bottom part of core CSB6 suggested Gauss normal polarity chron, an age of more than about 2600 ka. The other four cores showed initial deposition time between 200-60 ka B.P., significantly later than CSB6. We infer the reason is that CSB6 locating in the Changxin-Fenghua Fracture. Combined with data from referenced magnetostratigraphic cores in the Yangtze River Delta, we suggest that tectonic movement resulted in a much longer depositional age in some parts of the Yangtze River Delta and influenced the sedimentary characteristics of thick (North) to thin (South) and thick (East) to thin (West). In conclusion, a relatively wide range of deposition in the Yangtze River Delta occurred since about 200 ka B.P. The deposition of fine particles (clay-silt), which was controlled by slow tectonic subsidence and sea-level changes, expanded to the whole delta region after about 60 ka B.P. We propose that this time scale maybe used for further study on the evolution of the Yangtze delta's paleoclimate and paleoenvironment. References [1]Peng J,Yang X Q,Qiang X K,et al.Magnetostratigraphy characteristics of several cores around the Qiantang River mouth and its significance.Chinese J.Geophys.(in Chinese),2016,59(8):2949-2964. [2]Li C X, Chen Q Q, Zhang J Q,et al. Stratigraphy and paleoenvironmental changes in the Yangtze Delta during the Late Quaternary

Hydrogeology of the western part of the Salt River Valley area, Maricopa County, Arizona

USGS Publications Warehouse

Brown, James G.; Pool, D.R.

1989-01-01

The Salt River Valley is a major population and agricultural center of more than 3,000 mi2 in central Arizona (fig. 1). The western part of the Salt River Valley area (area of this report) covers about 1,500 mi2. The Phoenix metropolitan area with a population of more than 1.6 million in 1985 (Valley National Bank, 1987) is located within the valley. The watersheds of the Salt, Verde, and Agua Fria Rivers provide the valley with a reliable but limited surface-water supply that must be augmented with ground water even in years of plentiful rainfall. Large-scale ground-water withdrawals began in the Salt River Valley in the early part of the 20th century; between 1915 and 1983, the total estimated ground-water pumpage was 81 million acre-ft (U.S. Geological Survey, 1984). Because of the low average annual rainfall and high potential evapotranspiration, the principal sources of ground-water recharge are urban runoff, excess irrigation, canal seepage and surface-water flows during years of higher-than-normal rainfall. Withdrawals greatly exceed recharge and, in some area, ground-water levels have declines as much as 350 ft (Laney and other, 1978; Ross, 1978). In the study area, ground-water declines of more than 300 ft have occurred in Deer Valley and from Luke Air Force Base north to Beardsley. As a result, a large depression of the water table has developed west of Luke Air Force Base (fig. 2). Ground-water use has decreased in recent years because precipitation and surface-water supplies have been greater than normal. Increased precipitation also caused large quantities of runoff to be released into the normally dry Salt and Gila River channels. From February 1978 to June 1980, streamflow losses of at least 90,000 acre-ft occurred between Jointhead Dam near the east boundary of the study area and Gillespie Dam several miles southwest of the west edge of the study area (Mann and Rhone, 1983). Consequently, ground-water declines in a large part of the basin have

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

NASA Astrophysics Data System (ADS)

Li, X.

2017-12-01

The expanding and developing of agriculture are the basic of population growth, the expansions of material cultures and civilization. The Huanghe River valley, as the origin center of millet agriculture, lies between the heartlands of wheat and rice, which gestates the flourishing Neolithic culture based on agriculture. Recent work using botanical remains has greatly expanded the knowledge concerning early agriculture. Here, we report the new progress on the development and adaption of early agriculture in Huanghe River valley and the surrounding areas. Based on the analysis of phytolith from 13 sites in middle reaches of Huanghe River and the survey of crop seeds from 5 sites in Guanzhong Basin, the rice have been cultivated around 7600 cal BP in semi-humid regions dominated by rain-fed agriculture. The mixed agriculture of common millet, foxtail millet, and rice continued to exist between 7600-3500 BP. In semi-arid region of Huanghe River valley, the agriculture was dominated by the production of common and foxtail millet and 3 major changes have taken place around 6500 BP, 5500 BP, and 4000 BP during Neolithic. The cultivating ratio of common and foxtail millet was adjusted by farmer for adapting the climate changes during Holocene. Approximately 5000 yr BP, the rain-fed agriculture continues to break geographical boundaries to expand to west and southwest from Huanghe River valley. Millet agriculture appeared in southern Ganshu and north eastern Tibetan Plateau. The common and foxtail millet spread to the arid-area of Hexi corridor, a major crossroad of the famous Silk Road, around 4500 yr BP. Wheat was added as a new crop to the existing millet based agricultural systems around 4100-4000 cal yr BP in Hexi corridor. Between 3800 and 3400 cal yr BP, the proportion of wheat and barley in agriculture was up to 90%,which have replaced the local millet and become the main crops. And now, some new evidences of wheat agriculture from NW Xijiang have been obtained and

The Brahmaputra River: a stratigraphic analysis of Holocene avulsion and fluvial valley reoccupation history

NASA Astrophysics Data System (ADS)

Hartzog, T. R.; Goodbred, S. L.

2011-12-01

The Brahmaputra River, one of the world's largest braided streams, is a major component of commerce, agriculture, and transportation in India and Bangladesh. Hence any significant change in course, morphology, or behavior would be likely to influence the regional culture and economy that relies on this major river system. The history of such changes is recorded in the stratigraphy deposited by the Brahmaputra River during the Holocene. Here we present stratigraphic analysis of sediment samples from the boring of 41 tube wells over a 120 km transect in the upper Bengal Basin of northern Bangladesh. The transect crosses both the modern fluvial valley and an abandoned fluvial valley about 60 km downstream of a major avulsion node. Although the modern Brahmaputra does not transport gravel, gravel strata are common below 20 m with fluvial sand deposits dominating most of the stratigraphy. Furthermore, the stratigraphy preserves very few floodplain mud strata below the modern floodplain mud cap. These preliminary findings will be assessed to determine their importance in defining past channel migration, avulsion frequency, and the reoccupation of abandoned fluvial valleys. Understanding the avulsion and valley reoccupation history of the Brahmaputra River is important to assess the risk involved with developing agriculture, business, and infrastructure on the banks of modern and abandoned channels. Based on the correlation of stratigraphy and digital surface elevation data, we hypothesize that the towns of Jamalpur and Sherpur in northern Bangladesh were once major ports on the Brahmaputra River even though they now lie on the banks of small underfit stream channels. If Jamalpur and Sherpur represent the outer extent of the Brahmaputra River braid-belt before the last major avulsion, these cities and any communities developed in the abandoned braid-belt assume a high risk of devastation if the next major avulsion reoccupies this fluvial valley. It is important to

Ground-water hydrology of the upper Sevier River Basin, south-central Utah, and simulation of ground-water flow in the valley-fill in Panguitch Valley.

USGS Publications Warehouse

Thiros, Susan A.; Brothers, William C.

1993-01-01

The ground-water hydrology of the upper Sevier River basin, primarily of the unconsolidated valley-fill aquifers, was studied from 1988 to 1989. Recharge to the valley-fill aquifers is mostly by seepage from surface-water sources. Changes in soil-moisture content am water levels were measured in Panguitch Valley both at a flood-irrigated and at a sprinkler-irrigated alfalfa field to quantify seepage from unconsumed irrigation water. Lag time between irrigation and water-level response decreased from 6 to 2 days in the flood-irrigated field as the soil-moisture content increased. Water levels measured in the sprinkler-irrigated field did not respond to irrigation. Discharge from the valley-fill aquifer to the Sevier River in Panguitch Valley is about 53,570 acre-feet per year.Water levels measured in wells from 1951 to 1989 tend to fluctuate with the quantity of precipitation falling at higher elevations. Ground-water discharge to the Sevier River in Panguitch Valley causes a general increase in the specific conductance of the river in a downstream direction.A three-layered ground-water-flow model was used to simulate the effects of changes in irrigation practices am increased ground-water withdrawals in Panguitch Valley. The establishment of initial conditions consisted of comparing simulated water levels and simulated gains and losses from the Sevier River and selected canals with values measured during the 1988 irrigation season. The model was calibrated by comparing water-level changes measured from 1961 to 1963 to simulated changes. A simulated change from flood to sprinkler irrigation resulted in a maximum decline in water level of 0.9 feet after the first year of change. Simulating additional discharge from wells resulted in drawdowns of about 20 feet after the first year of pumping.

Gypsum scarps and asymmetric fluvial valleys in evaporitic terrains. The role of river migration, landslides, karstification and lithology (Ebro River, NE Spain)

NASA Astrophysics Data System (ADS)

Guerrero, J.; Gutiérrez, F.

2017-11-01

Most of the Spanish fluvial systems excavated in Tertiary evaporitic gypsum formations show asymmetric valleys characterized by a stepped sequence of fluvial terraces on one valley flank and kilometric-long and > 100-m high prominent river scarp on the opposite side of the valley. Scarp undermining by the continuous preferential lateral migration of the river channel toward the valley margin leads to vertical to overhanging unstable slopes affected by a large number of slope failures that become the main geological hazard for villages located at the toe of the scarps. Detailed mapping of the gypsum scarps along the Ebro and Huerva Rivers gypsum scarps demonstrates that landslides and lateral spreading processes are predominant when claystones crop out at the base of the scarp, while rockfalls and topples become the dominant movement in those reaches where the rock mass is mainly constituted by evaporites. The dissolution of gypsum nodules, seasonal swelling and shrinking, and dispersion processes contribute to a decrease in the mechanical strength of claystones. The existence of dissolution-enlarged joints, sinkholes, and severely damaged buildings at the toe of the scarp from karstic subsidence demonstrates that the interstratal karstification of evaporites becomes a triggering factor in the instability of the rock mass. The genesis of asymmetric valleys and river gypsum scarps in the study area seem to be caused by the random migration of the river channel in the absence of lateral tilting related to tectonics or dissolution-induced subsidence. Once the scarp is developed, its preservation depends on the physicochemical properties of the substratum, the ratio between bedrock erosion and river incision rates, and climatic conditions that favour runoff erosion versus dissolution.

Salinity in the Colorado River in the Grand Valley, western Colorado, 1994-95

USGS Publications Warehouse

Butler, David L.; von Guerard, Paul B.

1996-01-01

Salinity, or the dissolved-solids concentration, is the measure of salts such as sodium chloride, calcium bicarbonate, and calcium sulfate that are dissolved in water. About one-half of the salinity in the Colorado River Basin is from natural sources (U.S. Department of the Interior, 1995), such as thermal springs in the Glenwood-Dotsero area, located about 90 miles upstream from Grand Junction (fig. 1). Effects of human activities, such as irrigation, reservoir evaporation, and transbasin diversions, have increased the levels of salinity in the Colorado River. High salinity can affect industrial and municipal water users by causing increased water-treatment costs, increased deterioration of plumbing and appliances, increased soap needs, and undesirable taste of drinking water. High salinity also can cause lower crop yields by reducing water and nutrient uptake by plants and can increase agricultural production costs because of higher leaching and drainage requirements. Agricultural losses might occur when salinity reaches about 700?850 milligrams per liter (U.S Department of the Interior, 1994). Figure 1. Irrigated area in the Grand Valley and locations of sampling sites for the 1994?95 salinity study of the Colorado River. The Colorado River is the major source of irrigation water to the Grand Valley (fig. 1) and also is one source of water for the Clifton Water District, which supplies domestic water to part of the eastern Grand Valley. During spring and early summer in 1994, the Colorado River in the Grand Valley had lower than average streamflow. There was concern by water users about the effect of this low streamflow on salinity in the river. In 1994, the U.S. Geological Survey (USGS), in cooperation with the Colorado River Water Conservation District, began a study to evaluate salinity in the Colorado River. This fact sheet describes results of that study. The specific objectives of the fact sheet are to (1) compare salinity in the Colorado River among

Fertilisation of the Southern Atlantic: Ephemeral River Valleys as a replenishing source of nutrient-enriched mineral aerosols

NASA Astrophysics Data System (ADS)

Dansie, Andrew; Wiggs, Giles; Thomas, David

2016-04-01

Oceanic dust deposition provides biologically important iron and macronutrients (Phosphorus (P) and Nitrogen-based (N) compounds) that contribute to phytoplankton growth, marine productivity and oceanic atmospheric CO2 uptake. Research on dust emission sources to date has largely focused on the northern hemisphere and on ephemeral lakes and pans. Our work considers the ephemeral river valleys of the west coast of Namibia as an important yet overlooked source of ocean-fertilizing dust. Dust plumes are frequently emitted from the river valleys by strong easterly winds during the Southern Hemisphere winter, when the upwelling of the Benguela Current is at its weakest. We present field data from dust emission source areas along the main river channels near the coastal termini of the Huab, Kuiseb and Tsauchab river valleys. Collected data include erodible surface sediment, wind-blown flux, and associated meteorological data. Extensive surface sediment sampling was also undertaken throughout the combined 34,250 km2 extent of each river valley catchment with samples collected from within the main river channels, the main branches of each river system, selected tributaries, and into the upper watersheds. Geochemical data show valley sediment and wind-blown flux material have high concentrations of bioavailable Fe, P and N, exceeding that measured at the major dry lake basin dust sources in southern Africa. The contribution of fertilising deposition material is enhanced by both the spatial proximity of the source areas to the ocean and enrichment of source material by ephemeral fluvial accumulation and desiccation. Results show that geographical factors within each watershed play a key role in the nutrient composition of the emitting fluvial deposits in the river valleys. Analysis explores potential relationships between land use, geology, climate and precipitation in the upper watersheds and their influence on bioavailability of Fe, P and N compounds in wind

[Mutagenicity study of water samples from a waterworks taking Yangtze River as its water source in Jiangsu Province].

PubMed

Xiao, Sanhua; Luo, Lan; Qiao, Qian; Lü, Xuemin; Wang, Yanhui; Feng, Lin; Tang, Fei; Wang, Haiyong; Bie, Nana; Wang, Yuehong

2017-05-01

To understand the occurrence and change of mutagencity of water samples in the process of drinking water treatment and distribution in a waterworks taking Yangtze River as its water source in Jiangsu Province. Large volume of inlet water, finished water and tap water samples were extracted by XAD-2 resin. Mutagencities were assessed by Ames test and a mutation ratio( MR) of 2 or greater was judged as a positive result. Compared with the samples with S9, samples without S9 presented more positive results( P = 0. 005). That water treatment elevated MR values( P = 0. 007) while the pipe transport made MR values down( P = 0. 038) was observed in samples without S9. The tap water showed weaker mutagenicities than the raw water in samples with S9( P = 0. 008). Compared to the raw water samples, the finished water samples showed more positive results(-S9) and lower MR values( + S9, P =0. 002). Significant mutagenicities of water samples from the Yangtze Riverand its processed water were presented, and frame shit and direct mutagens deserved special concern.

Utilization potential evaluation of plant resources in the dry-hot valley of Jinsha River

NASA Astrophysics Data System (ADS)

Xi, Rong; Xu, Naizhong; Liu, Shengxiang; Ren, Tingyan

2017-08-01

Plant resources in the dry-hot valley of Jinsha River are endemic to a class of district. The article adopts the analytic hierarchy process method to evaluate the exploitation and utilization potential of plant resources of thirty typical plant resources on the basis of their characteristics in the dry-hot valley of Jinsha River, which provide scientific evidence for quantitative evaluation of regional plant resources, and we also suggest pathways offering protection and development.

Paper birch: Sentinels of climate change in the Niobrara River Valley, Nebraska

USGS Publications Warehouse

Stroh, Esther D.

2011-01-01

The Niobrara River Valley in the northern Great Plains supports scattered stands of paper birch (Betula papyrifera Marsh), a species more typical of boreal forests. These birch stands are considered to be relictual populations that have persisted since the end of the Wisconsin glaciation. Localized summer microclimates have likely facilitated the persistence of birch populations in a region otherwise unsuitable for the species. Dieback of canopy-sized birch has been observed throughout the valley in recent years, although no onset dates are documented. Changes in spring weather patterns may be causing rootlet injury so that trees die in spite of the still-cool summer microclimates. Current weather patterns, combined with little evidence of recruitment of young birch and great geographic distances from potential immigrant sources, make the future persistence of birch in the Niobrara River Valley stands uncertain.

Diagnostic heavy minerals in Plio-Pleistocene sediments of the Yangtze Coast, China with special reference to the Yangtze River connection into the sea

NASA Astrophysics Data System (ADS)

Chen, Jing; Wang, Zhanghua; Chen, Zhongyuan; Wei, Zixin; Wei, Taoyuan; Wei, Wei

2009-12-01

This present study revealed five heavy mineral zones in the Yangtze coastal borehole sediments. Ilmenite, garnet and zircon suite of Zone I of the Pliocene characterizes the derivation of basaltic bedrock and local andesitic-granitic rocks. Indicative limonite in the Zone I sediments formed as alluvial fan facies shows strong chemical weathering. The assemblage of amphibole, straurolite, kyanite and idocrase of metamorphic derivation, together with a few zircon and tourmaline of andesitic-granitic origin in Zone II, represents the extension of sediment sources to the lower and middle Yangtze basin in Early Pleistocene as the study area subsided. Also, the braided to meandering riverine facies demonstrates a longer distance sediment transport. Few heavy minerals remained in Zone III of Mid-Pleistocene, when mottled thicker stiff mud occurred as the lacustrine facies, suggesting a quasi-coastal floodplain with lower capability of sediment transport. Heavy minerals appeared significant and continuous in Zone IV of Late Pleistocene, when changing to the shallow marine facies, inferring much extended sediment sources to the upper Yangtze. Hypersthene, identified primarily in Zone IV, was closely associated with the Er-Mei Mountain tholeiite basalt of the upper Yangtze. Heavy minerals of Zone V remained almost the same as IV during Holocene, when the modern delta evolved. The heavy minerals suggested the timing of the Yangtze connection to the sea at ca 0.12 Ma BP.

A high-resolution genetic linkage map and QTL fine mapping for growth-related traits and sex in the Yangtze River common carp (Cyprinus carpio haematopterus).

PubMed

Feng, Xiu; Yu, Xiaomu; Fu, Beide; Wang, Xinhua; Liu, Haiyang; Pang, Meixia; Tong, Jingou

2018-04-02

A high-density genetic linkage map is essential for QTL fine mapping, comparative genome analysis, identification of candidate genes and marker-assisted selection for economic traits in aquaculture species. The Yangtze River common carp (Cyprinus carpio haematopterus) is one of the most important aquacultured strains in China. However, quite limited genetics and genomics resources have been developed for genetic improvement of economic traits in such strain. A high-resolution genetic linkage map was constructed by using 7820 2b-RAD (2b-restriction site-associated DNA) and 295 microsatellite markers in a F2 family of the Yangtze River common carp (C. c. haematopterus). The length of the map was 4586.56 cM with an average marker interval of 0.57 cM. Comparative genome mapping revealed that a high proportion (70%) of markers with disagreed chromosome location was observed between C. c. haematopterus and another common carp strain (subspecies) C. c. carpio. A clear 2:1 relationship was observed between C. c. haematopterus linkage groups (LGs) and zebrafish (Danio rerio) chromosomes. Based on the genetic map, 21 QTLs for growth-related traits were detected on 12 LGs, and contributed values of phenotypic variance explained (PVE) ranging from 16.3 to 38.6%, with LOD scores ranging from 4.02 to 11.13. A genome-wide significant QTL (LOD = 10.83) and three chromosome-wide significant QTLs (mean LOD = 4.84) for sex were mapped on LG50 and LG24, respectively. A 1.4 cM confidence interval of QTL for all growth-related traits showed conserved synteny with a 2.06 M segment on chromosome 14 of D. rerio. Five potential candidate genes were identified by blast search in this genomic region, including a well-studied multi-functional growth related gene, Apelin. We mapped a set of suggestive and significant QTLs for growth-related traits and sex based on a high-density genetic linkage map using SNP and microsatellite markers for Yangtze River common carp. Several

Arbuscular mycorrhizal fungi associations of vascular plants confined to river valleys: towards understanding the river corridor plant distribution.

PubMed

Nobis, Agnieszka; Błaszkowski, Janusz; Zubek, Szymon

2015-01-01

The group of river corridor plants (RCP) includes vascular plant species which grow mainly or exclusively in the valleys of large rivers. Despite the long recognized fact that some plant species display a corridor-like distribution pattern in Central Europe, there is still no exhaustive explanation of the mechanisms generating this peculiar distribution. The main goal of this study was therefore to investigate whether arbuscular mycorrhizal fungi (AMF) and fungal root endophytes influence the RCP distribution. Arbuscular mycorrhizae (AM) were observed in 19 out of 33 studied RCP. Dark septate endophytes (DSE) and Olpidium spp. were recorded with low abundance in 15 and 10 plant species, respectively. The spores of AMF were found only in 32% of trap cultures established from the soils collected in the river corridor habitats. In total, six widespread AMF species were identified. Because the percentage of non-mycorrhizal species in the group of RCP is significant and the sites in river corridors are characterized by low AMF species diversity, RCP can be outcompeted outside river valleys by the widespread species that are able to benefit from AM associations in more stable plant-AMF communities in non-river habitats.

[Investigation on knowledge, attitude, and practice of schistosomiasis prevention and control and infection status in Armed Police Forces stationed along Yangtze River].

PubMed

Ming-Zhen, He; Yi-Qing, Xie; Yan-Li, Guo; Hong, Chen; Yong-Gen, Zou; Shi-Ying, Zhu; You, Zhang

2016-12-21

To understand the status of knowledge, attitude, and practice of schistosomiasis prevention and control and infection status in Armed Police Forces stationed along the Yangtze River, so as to provide the reference for formulating the schistosomiasis prevention and control measures in Armed Police Forces. A questionnaire survey was conducted in the Armed Police Forces along the Yangtze River in Jiangsu Province, and the investigation content included social demographic data, schistosomiasis prevention knowledge, attitude and behavior. All the subjects were examined for Schistosoma japonicum infection. Totally 376 soldiers were investigated in 2 sites. The total passing rate of schistosomiasis knowledge was 72.87%. The passing rate among different age groups had no significant difference ( χ 2 =0.26, P > 0.05). The passing rate of soldiers from endemic areas was significantly higher than that of the soldiers from non-endemic areas ( χ 2 =4.71, P < 0.05). The passing rate of officers was significantly higher than that of the soldiers ( χ 2 = 4.21, P < 0.05). The passing rate of soldiers with the education levels of junior school, high school, college, undergraduate and above increased gradually, with a significant difference ( χ 2 =8.16, P < 0.05). The soldiers with positive attitude accounted for 93.88%. Among the water contact behaviors, training accounted for 17.55% and participating in the task (such as flood fighting and water work) accounted for 86.44%. When launching, the rate of taking protective measures was 52.93%. The rate of taking protective measures in the knowledge passing group was much higher than that in the knowledge failed group ( χ 2 =10.55, P < 0.05). The stool was harmlessly treated in the two camps. Among 376 soldiers, the positive rate of blood examinations was 0.53%, but the stool examinations were all negative. The overall level of knowledge and correct behavior of schistosomiasis prevention in the Armed Police Forces along the Yangtze

Accounting System for Water Use by Vegetation in the Lower Colorado River Valley

USGS Publications Warehouse

Owen-Joyce, Sandra J.

1992-01-01

The Colorado River is the principal source of water in the valley of the Colorado River between Hoover Dam and the international boundary with Mexico (fig. 1). Agricultural, domestic, municipal, industrial, hydroelectric-power genera-tion, and recreation are the primary uses of river water in the valley. Most of the consumptive use of water from the river occurs downstream from Davis Dam, where water is diverted to irrigate crops along the river or is exported to interior regions of California and Arizona. Most of the agricultural areas are on the alluvium of the flood plain; in a few areas, land on the alluvial terraces has been cultivated. River water is consumed mainly by vegetation (crops and phreatophytes) on the flood plain. Crops were grown on 70.3 percent of the vegetated area classified by using 1984 digital image satellite data. Phreatophytes, natural vege-tation that obtain water from the alluvial aquifer, covered the remaining vegetated areas on the uncultivated flood plain. Most of the water used for irrigation is diverted or pumped from the river. In some areas, water is pumped from wells completed in the alluvial aquifer, which is hydraulically connected to the river.

Spatial distribution of planktonic bacterial and archaeal communities in the upper section of the tidal reach in Yangtze River

PubMed Central

Fan, Limin; Song, Chao; Meng, Shunlong; Qiu, Liping; Zheng, Yao; Wu, Wei; Qu, Jianhong; Li, Dandan; Zhang, Cong; Hu, Gengdong; Chen, Jiazhang

2016-01-01

Bacterioplankton and archaeaplankton communities play key roles in the biogeochemical processes of water, and they may be affected by many factors. In this study, we used high-throughput 16S rRNA gene sequencing to profile planktonic bacterial and archaeal community compositions in the upper section of the tidal reach in Yangtze River. We found that the predominant bacterial phyla in this river section were Proteobacteria, Firmicutes, and Actinobacteria, whereas the predominant archaeal classes were Halobacteria, Methanomicrobia, and unclassified Euryarchaeota. Additionally, the bacterial and archaeal community compositions, richnesses, functional profiles, and ordinations were affected by the spatial heterogeneity related to the concentration changes of sulphate or nitrate. Notably, the bacterial community was more sensitive than the archaeal community to changes in the spatial characteristics of this river section. These findings provide important insights into the distributions of bacterial and archaeal communities in natural water habitats. PMID:27966673

Spatial distribution of planktonic bacterial and archaeal communities in the upper section of the tidal reach in Yangtze River

NASA Astrophysics Data System (ADS)

Fan, Limin; Song, Chao; Meng, Shunlong; Qiu, Liping; Zheng, Yao; Wu, Wei; Qu, Jianhong; Li, Dandan; Zhang, Cong; Hu, Gengdong; Chen, Jiazhang

2016-12-01

Bacterioplankton and archaeaplankton communities play key roles in the biogeochemical processes of water, and they may be affected by many factors. In this study, we used high-throughput 16S rRNA gene sequencing to profile planktonic bacterial and archaeal community compositions in the upper section of the tidal reach in Yangtze River. We found that the predominant bacterial phyla in this river section were Proteobacteria, Firmicutes, and Actinobacteria, whereas the predominant archaeal classes were Halobacteria, Methanomicrobia, and unclassified Euryarchaeota. Additionally, the bacterial and archaeal community compositions, richnesses, functional profiles, and ordinations were affected by the spatial heterogeneity related to the concentration changes of sulphate or nitrate. Notably, the bacterial community was more sensitive than the archaeal community to changes in the spatial characteristics of this river section. These findings provide important insights into the distributions of bacterial and archaeal communities in natural water habitats.

Chemical weather forecasting for the Yangtze River Delta

NASA Astrophysics Data System (ADS)

Xie, Y.; Xu, J.; Zhou, G.; Chang, L.; Chen, B.

2016-12-01

Shanghai is one of the largest megacities in the world. With rapid economic growth of the city and its surrounding areas in recent years, air pollution has posed adverse effects on public health and ecosystem. In winter heavy pollution episodes are often associated with PM exceedances under stagnant conditions or transport events, whereas in summer the region frequently experiences elevated O3 levels. Chemical weather prediction systems with the WRF-Chem and CMAQ models are being developed to support air quality and haze forecasting for Shanghai and the Yangtze River Delta region. We will present main components of the modeling system, forecasting products, as well as evaluation results. Evaluation of the WRF-Chem forecasts show the model has generally good ability to capture the temporal variations of O3 and PM2.5. Substantial regional differences exist, with the best performance in Shanghai. Meanwhile, the forecasts tend to degrade during highly polluted episodes and transitional time periods, which highlights the need to improve model representation of key process (e.g. meteorological fields and formation of secondary pollutants). Recent work includes using the ECMWF global model forecasts as chemical boundary conditions for our regional model. We investigate the impact of chemical downscaling, and also compare the results from different models participated in the PANDA (PArtnership with chiNa on space Data) project. Results from ongoing efforts (e.g. chemical weather forecasting driven by SMS regional high resolution NWP) will also be presented.

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

NASA Astrophysics Data System (ADS)

Liu, W.; Kuo, Y. M.

2016-12-01

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

Why was the strengthening of rainfall in summer over the Yangtze River valley in 2016 less pronounced than that in 1998 under similar preceding El Niño events?—Role of midlatitude circulation in August

NASA Astrophysics Data System (ADS)

Li, Chaofan; Chen, Wei; Hong, Xiaowei; Lu, Riyu

2017-11-01

It is widely recognized that rainfall over the Yangtze River valley (YRV) strengthens considerably during the decaying summer of El Niño, as demonstrated by the catastrophic flooding suffered in the summer of 1998. Nevertheless, the rainfall over the YRV in the summer of 2016 was much weaker than that in 1998, despite the intensity of the 2016 El Niño having been as strong as that in 1998. A thorough comparison of the YRV summer rainfall anomaly between 2016 and 1998 suggests that the difference was caused by the sub-seasonal variation in the YRV rainfall anomaly between these two years, principally in August. The precipitation anomaly was negative in August 2016—different to the positive anomaly of 1998. Further analysis suggests that the weaker YRV rainfall in August 2016 could be attributable to the distinct circulation anomalies over the midlatitudes. The intensified "Silk Road Pattern" and upper-tropospheric geopotential height over the Urals region, both at their strongest since 1980, resulted in an anticyclonic circulation anomaly over midlatitude East Asia with anomalous easterly flow over the middle-to-lower reaches of the YRV in the lower troposphere. This easterly flow reduced the climatological wind, weakened the water vapor transport, and induced the weaker YRV rainfall in August 2016, as compared to that in 1998. Given the unique sub-seasonal variation of the YRV rainfall in summer 2016, more attention should be paid to midlatitude circulation—besides the signal in the tropics—to further our understanding of the predictability and variation of YRV summer rainfall.

Stratigraphy of the Mississippi-Alabama shelf and the Mobile River incised-valley system

USGS Publications Warehouse

Kindinger, Jack G.; Balson, Peter S.; Flocks, James G.; Dalrymple, Robert W.; Boyd, Ron; Zaitlin, Brian A.

1994-01-01

The Holocene incised-valley fill (estuarine facies) underlying Mobile Buy fit well into the conceptual facies model of a microtidal wave-dominated estuary. The model does not fit as well, however, with the rapidly transgressed shelf portion of the incised valley. The down dip section does not contain a clearly identifiable (from seismic profiles) estuarine facies; the valley fill is primarily fluvial and is overlain by marine shoals. In the Mobile River incised valley, the distal portion of the valley was rapidly drowned, allowing the thin estuarine facies to be reworked. The proximal portion was drowned more slowly, leaving the estuarine facies intact. Thus, the single incised valley contains two very different types of fill.

The diel rhythms of biosonar behavior in the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) in the port of the Yangtze River: The correlation between prey availability and boat traffic.

PubMed

Wang, Zhitao; Akamatsu, Tomonari; Wang, Kexiong; Wang, Ding

2014-01-01

Information on the habitat use of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is critical for its conservation. The diel biosonar behavior of the porpoise in the port areas of the Yangtze River was examined along with simultaneous observations of fish density and boat traffic. Biosonar pulses from the porpoises were detected for 1233 min (5.77%) over a 21,380 min duration of effective observations. In total, 190 (5.63%) buzzes (an indication of prey capture attempts) were recorded among the 3372 identified click trains. Of the 168 echolocation encounters (bouts of click trains less than eight min apart), 150 (89.3%) involved single animals, indicating that solitary porpoises were frequently present and feeding in the port areas. Significant diel patterns were evident involving the biosonar behavior of the porpoises (including click trains and buzzes), fish density and boat traffic. The frequencies of the click trains and buzzes were significantly lower during the day than in the evening and at night, which suggests that porpoises in this region are primarily engaged in crepuscular and nocturnal foraging. The lack of a significant diel pattern in the echolocation encounters indicates the importance of the port in porpoise conservation. A forced feeding schedule may be associated with the lack of a significant correlation between porpoise acoustics and boat traffic. Overall, prey availability appears to be the primary factor that attracts porpoises. Additionally, porpoises tend to migrate or remain downstream in the morning and migrate or remain upstream in the evening, most likely to follow their prey. The findings of this study can be used to improve the conservation of the Yangtze finless porpoise.

The Diel Rhythms of Biosonar Behavior in the Yangtze Finless Porpoise (Neophocaena asiaeorientalis asiaeorientalis) in the Port of the Yangtze River: The Correlation between Prey Availability and Boat Traffic

PubMed Central

Wang, Zhitao; Akamatsu, Tomonari; Wang, Kexiong; Wang, Ding

2014-01-01

Information on the habitat use of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is critical for its conservation. The diel biosonar behavior of the porpoise in the port areas of the Yangtze River was examined along with simultaneous observations of fish density and boat traffic. Biosonar pulses from the porpoises were detected for 1233 min (5.77%) over a 21,380 min duration of effective observations. In total, 190 (5.63%) buzzes (an indication of prey capture attempts) were recorded among the 3372 identified click trains. Of the 168 echolocation encounters (bouts of click trains less than eight min apart), 150 (89.3%) involved single animals, indicating that solitary porpoises were frequently present and feeding in the port areas. Significant diel patterns were evident involving the biosonar behavior of the porpoises (including click trains and buzzes), fish density and boat traffic. The frequencies of the click trains and buzzes were significantly lower during the day than in the evening and at night, which suggests that porpoises in this region are primarily engaged in crepuscular and nocturnal foraging. The lack of a significant diel pattern in the echolocation encounters indicates the importance of the port in porpoise conservation. A forced feeding schedule may be associated with the lack of a significant correlation between porpoise acoustics and boat traffic. Overall, prey availability appears to be the primary factor that attracts porpoises. Additionally, porpoises tend to migrate or remain downstream in the morning and migrate or remain upstream in the evening, most likely to follow their prey. The findings of this study can be used to improve the conservation of the Yangtze finless porpoise. PMID:24823945

Quantifying the impact of the Three Gorges Dam on the thermal dynamics of the Yangtze River

NASA Astrophysics Data System (ADS)

Cai, Huayang; Piccolroaz, Sebastiano; Huang, Jingzheng; Liu, Zhiyong; Liu, Feng; Toffolon, Marco

2018-05-01

This study examines the impact of the world’s largest dam, the Three Gorges Dam (TGD), on the thermal dynamics of the Yangtze River (China). The analysis uses long-term observations of river water temperature (RWT) in four stations and reconstructs the RWT that would have occurred in absence of the TGD. Relative to pre-TGD conditions, RWT consistently warmed in the region due to air temperature (AT) increase. In addition, the analysis demonstrates that the TGD significantly affected RWT in the downstream reach. At the closest downstream station (Yichang) to the TGD, the annual cycle of RWT experienced a damped response to AT and a marked seasonal alteration: warming during all seasons except for spring and early summer which were characterized by cooling. Both effects were a direct consequence of the larger thermal inertia of the massive water volume stored in the TGD reservoir, causing the downstream reach to be more thermally resilient. The approach used here to quantify the separate contributions of climate and human interventions on RWT can be used to set scientific guidelines for river management and conservation planning strategies.

Characterization and simulation of ground-water flow in the Kansas River Valley at Fort Riley, Kansas, 1990-98

USGS Publications Warehouse

Myers, Nathan C.

2000-01-01

Hydrologic data and a ground-water flow model were used to characterize ground-water flow in the Kansas River alluvial aquifer at Fort Riley in northeast Kansas. The ground-water flow model was developed as a tool to project ground-water flow and potential contaminant-transport paths in the alluvial aquifer on the basis of past hydrologic conditions. The model also was used to estimate historical and hypothetical ground-water flow paths with respect to a private- and several public-supply wells. The ground-water flow model area extends from the Smoky Hill and Republican Rivers downstream to about 2.5 miles downstream from the city of Ogden. The Kansas River Valley has low relief and, except for the area within the Fort Riley Military Reservation, is used primarily for crop production. Sedimentary deposits in the Kansas River Valley, formed after the ancestral Kansas River eroded into bedrock, primarily are alluvial sediment deposited by the river during Quaternary time. The alluvial sediment consists of as much as about 75 feet of poorly sorted, coarse-to-fine sand, silt, and clay, 55 feet of which can be saturated with ground water. The alluvial aquifer is unconfined and is bounded on the sides and bottom by Permian-age shale and limestone bedrock. Hydrologic data indicate that ground water in the Kansas River Valley generally flows in a downstream direction, but flow direction can be quite variable near the Kansas River due to changes in river stage. Ground-water-level changes caused by infiltration of precipitation are difficult to detect because they are masked by larger changes caused by fluctuation in Kansas River stage. Ratios of strontium isotopes Sr87 and Sr86 in water collected from wells in the Camp Funston Area indicate that the ground water along the northern valley wall originates, in part, from upland areas north of the river valley. Water from Threemile Creek, which flows out of the uplands north of the river valley, had Sr87:Sr86 ratios similar to

Riparian valley oak (Quercus lobata) forest restoration on the middle Sacramento River, California

Treesearch

F. Thomas Griggs; Gregory H. Golet

2002-01-01

In 1989 The Nature Conservancy initiated a riparian horticultural restoration program on the floodplain of the middle Sacramento River, California. At nearly all restoration sites Valley oak (Quercus lobata Nee) comprised a major component of the planting design. Valley oaks are a keystone tree species of lowland floodplain habitats in California...

Paleogeomorphology of the early Colorado River inferred from relationships in Mohave and Cottonwood Valleys, Arizona, California and Nevada

USGS Publications Warehouse

Pearthree, Philip; House, P. Kyle

2014-01-01

Geologic investigations of late Miocene–early Pliocene deposits in Mohave and Cottonwood valleys provide important insights into the early evolution of the lower Colorado River system. In the latest Miocene these valleys were separate depocenters; the floor of Cottonwood Valley was ∼200 m higher than the floor of Mohave Valley. When Colorado River water arrived from the north after 5.6 Ma, a shallow lake in Cottonwood Valley spilled into Mohave Valley, and the river then filled both valleys to ∼560 m above sea level (asl) and overtopped the bedrock divide at the southern end of Mohave Valley. Sediment-starved water spilling to the south gradually eroded the outlet as siliciclastic Bouse deposits filled the lake upstream. When sediment accumulation reached the elevation of the lowering outlet, continued erosion of the outlet resulted in recycling of stored lacustrine sediment into downstream basins; depth of erosion of the outlet and upstream basins was limited by the water levels in downstream basins. The water level in the southern Bouse basin was ∼300 m asl (modern elevation) at 4.8 Ma. It must have drained and been eroded to a level <150 m asl soon after that to allow for deep erosion of bedrock divides and basins upstream, leading to removal of large volumes of Bouse sediment prior to massive early Pliocene Colorado River aggradation. Abrupt lowering of regional base level due to spilling of a southern Bouse lake to the Gulf of California could have driven observed upstream river incision without uplift. Rapid uplift of the entire region immediately after 4.8 Ma would have been required to drive upstream incision if the southern Bouse was an estuary.

Source apportionment of surface ozone in the Yangtze River Delta, China in the summer of 2013

NASA Astrophysics Data System (ADS)

Li, L.; An, J. Y.; Shi, Y. Y.; Zhou, M.; Yan, R. S.; Huang, C.; Wang, H. L.; Lou, S. R.; Wang, Q.; Lu, Q.; Wu, J.

2016-11-01

We applied ozone source apportionment technology (OSAT) with tagged tracers coupled within the Comprehensive Air Quality Model with Extensions (CAMx) to study the region and source category contribution to surface ozone in the Yangtze River Delta area in summer of 2013. Results indicate that the daytime ozone concentrations in the YRD region are influenced by emissions both locally, regionally and super-regionally. At urban Shanghai, Hangzhou and Suzhou receptors, the ozone formation is mainly VOC-limited, precursor emissions form Zhejiang province dominate their O3 concentrations. At the junction area among two provinces and Shanghai city, the ozone is usually influenced by all the three areas. The daily max O3 at the Dianshan Lake in July are contributed by Zhejiang (48.5%), Jiangsu (11.7%), Anhui (11.6%) and Shanghai (7.4%), long-range transport constitutes around 20.9%. At Chongming site, the BVOC emissions rate is higher than urban region. Regional contribution results show that Shanghai constitutes 15.6%, Jiangsu contributes 16.2% and Zhejiang accounts for 25.5% of the daily max O3. The analysis of the source category contribution to high ozone in the Yangtze River Delta region indicates that the most significant anthropogenic emission source sectors contributing to O3 pollution include industry, vehicle exhaust, although the effects vary with source sector and selected pollution episodes. Emissions of NOx and VOCs emitted from the fuel combustion of industrial boilers and kilns, together with VOCs emissions from industrial process contribute a lot to the high concentrations in urban Hangzhou, Suzhou and Shanghai. The contribution from regional elevated power plants cannot be neglected, especially to Dianshan Lake. Fugitive emissions of volatile pollution sources also have certain contribution to regional O3. These results indicate that the regional collaboration is of most importance to reduce ambient ozone pollution, particularly during high ozone episodes.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Blood lead level is associated with non-alcoholic fatty liver disease in the Yangtze River Delta region of China in the context of rapid urbanization.

PubMed

Zhai, Hualing; Chen, Chi; Wang, Ningjian; Chen, Yi; Nie, Xiaomin; Han, Bing; Li, Qin; Xia, Fangzhen; Lu, Yingli

2017-08-31

China has undergone rapid urbanization in the past three decades. We aimed to report blood lead level (B-Pb) in the most rapidly urbanized Yangtze River Delta Region of China, and explore the association B-Pb and non-alcoholic fatty liver disease (NAFLD). Our data source was the SPECT-China study. We enrolled 2011 subjects from 6 villages in the Yangtze River Delta Region. Lead was measured by atomic absorption spectrometry. According to abdominal ultrasound, residents were divided into normal and NAFLD groups. In total, 824 (41.0%) were diagnosed with NAFLD. Medians (interquartile range) of B-Pb were 5.29 μg/dL (3.60-7.28) [0.25 μmol/L (0.17-0.35)] for men and 4.49 μg/dL (2.97-6.59) [0.22 μmol/L (0.14-0.32)] for women. In both genders, the NAFLD group had significantly greater B-Pb than normal group (both P < 0.001). The prevalence of NAFLD significantly increased with increasing B-Pb quartiles in men (P for trend = 0.032) and women (P for trend = 0.001). Residents in Shanghai had significantly greater B-Pb (P < 0.001) and a higher prevalence of NAFLD (P < 0.001). Compared with women in the lowest quartile of BLL, OR of NAFLD in women in the highest quartile was 1.613 (95%CI 1.082-2.405) (P for trend = 0.019) after multivariable adjustment. In men, this association showed marginal significance (OR 2.168, 95%CI 0.989-4.750, P for trend = 0.063). B-Pb in Chinese residents in the Yangtze River Delta Region were much higher than in developed countries. Elevated B-Pb was associated with an increased risk of NAFLD, especially in women.

River Valley pluton, Ontario - A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

NASA Technical Reports Server (NTRS)

Ashwal, Lewis D.; Wooden, Joseph L.

1989-01-01

This paper presents Nd, Sr, and Pb isotopic data indicating a late-Archean/early-Proterozoic age for the River Valley anorthositic pluton of the southwestern Grenville Province of Sudbury, Ontario. Pb-Pb isotopic data on 10 whole-rock samples ranging in composition from anorthosite to gabbro yield an age of 2560 + or - 155 Ma. The River Valley pluton is thus the oldest anorthositic intrusive yet recognized within the Grenville Province. The Sm-Nd isotopic system records an age of 2377 + or - 68 Ma. High Pb-208/Pb-204 of deformed samples relative to igneous-textured rocks implies Th introduction and/or U loss during metamorphism in the River Valley area. Rb-Sr data from igneous-textured and deformed samples and from mineral separates give an age of 2185 + or - 105 Ma, indicating substantial disturbance of the Rb-Sr isotopic system.

Lead-rich sediments, Coeur d'Alene River Valley, Idaho: area, volume, tonnage, and lead content

USGS Publications Warehouse

Bookstrom, Arthur A.; Box, Stephen E.; Campbell, Julie K.; Foster, Kathryn I.; Jackson, Berne L.

2001-01-01

In north Idaho, downstream from the Coeur d?Alene (CdA) silver-lead-zinc mining district, lead-rich sediments, containing at least 1,000 ppm of lead, cover approximately 61 km2 (or 73 percent) of the 84-km2 floor of the CdA River valley, from the confluence of its North and South Forks to the top of its delta-front slope, in CdA Lake. Concentrations of lead (Pb) in surface sediments range from 15 to about 38,500 ppm, and average 3,370 ppm, which is 112 times the mean background concentration (30 ppm) of Pb in uncontaminated sediments of the CdA and St. Joe River valleys. Most of the highest concentrations of Pb are in sediments within or near the river channel, or near the base of the stratigraphic section of Pb-rich sediments. Ranges of Pb concentration in Pb-rich sediments gradually decrease with increasing distance from the river and its distributaries. Ranges of thickness of Pb-rich sediments generally decrease abruptly with increasing distance from the river, from about 3 + 3 m in the river channel to about 1 + 1m on upland riverbanks, levees and sand splays, to about 0.3 + 0.3 m in back-levee marshes and lateral lakes. Thickness of Pb-rich dredge spoils (removed from the river and deposited on Cataldo-Mission Flats) is mostly in the range 4 + 4 m, thinning away from an outfall zone north and west of the river, near the formerly dredged channel reach near Cataldo Landing. We attribute lateral variation in ranges of thickness and Pb content of Pb-rich sediments to the dynamic balance between decreasing floodwater flow velocity with increasing distance from the river and the quantity, size, density, and Pb content of particles mobilized, transported, and deposited. We present alternative median- and mean-based estimates of the volume of Pbrich sediments, their wet and dry tonnage, and their tonnage of contained Pb. We calculate separate pairs of estimates for 23 Estimation Units, each of which corresponds to a major depositional environment, divided into down-valley

The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China.

PubMed

Huang, Qunfang; Lu, Yuqi

2015-07-27

The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957-2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming.

The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China

PubMed Central

Huang, Qunfang; Lu, Yuqi

2015-01-01

The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957–2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming. PMID:26225986

Spatial distribution of bisphenol S in surface water and human serum from Yangtze River watershed, China: Implications for exposure through drinking water.

PubMed

Wan, Yanjian; Xia, Wei; Yang, Shunyi; Pan, Xinyun; He, Zhenyu; Kannan, Kurunthachalam

2018-05-01

Bisphenol S (BPS) is an emerging environmental contaminant. The occurrence of this compound in humans and the environment is not well described. In this study, 120 surface water samples and 240 human serum samples were collected along the Yangtze River in 2015 for the determination of the occurrence of BPS. Surface water and human serum samples were extracted by solid phase extraction and liquid-liquid extraction, respectively, and analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). BPS was detected in all river water samples at concentrations that ranged from 0.18 to 14.9 ng/L (median: 0.98 ng/L), with higher concentrations in spring than summer. The median estimated daily intake (EDI) of BPS through water ingestion by infants in spring and summer was 0.12 and 0.06 ng/kg body weight (bw)/day, respectively. BPS was detected in human serum with the highest concentrations in samples from Nanjing (median: 0.65 ng/mL, maximum: 169 ng/mL) among the four cities studied. No significant gender related difference in BPS concentrations was observed in human sera, while higher concentrations were found in younger individuals than elderly. The EDI of BPS calculated based on serum concentrations of adults in Nanjing was 22.8 ng/kg bw/day. Ingestion of water accounted for <1% of the total BPS intake by the Chinese population. This is the first report of the occurrence of BPS in water from the Yangtze River and human serum from several cities located along this river in China. Copyright © 2018 Elsevier Ltd. All rights reserved.

Long-term measurements of agronomic crop irrigation in the Mississippi Delta portion of the Lower Mississippi River Valley

USDA-ARS?s Scientific Manuscript database

With over 4 million ha irrigated cropland, the Lower Mississippi River Valley (LMRV) is a highly productive agricultural region where irrigation practices are similar and the Mississippi River Valley alluvial aquifer (MRVA) is a primary source of on-demand irrigation. Owing to agricultural exports, ...

[Effect of water storage and aquaculture on Oncomelania hupensis control in tidal flats wetlands of islet-beach type area of Dantu section of lower reaches of Yangtze River].

PubMed

Li, Ye-fang; Huang, Yi-xin; Wang, He-sheng; Hang, De-rong; Chen, Xiang-ping; Xie, Yi-feng; Zhang, Lian-heng

2015-12-01

To evaluate the effect and the benefits of the projects of water storage and aquaculture on Oncomelania hupensis snail control in the tidal flats wetlands of islet-beach type area of lower reaches of the Yangtze River. The projects of water storage and aquaculture on 0. hupensis snail control were implemented in the tidal flats wetlands of islet-beach type of lower reaches of the Yangtze River. The breed situation of the snails was investigated by the conventional method before and after the project implementation and the effect of control and elimination of the snails by the projects were evaluated. At the same time, the cost-benefit analysis of two projects among them was performed by the static benefit-cost ratio method. All of 0. hupensis snails were eliminated in the first year after the implementation of seven water storage and aquaculture projects. The costs of detection and control of snails saved by each project was 69.20 thousand yuan a year on average. The annual net benefits of the "Nanhao Group 10 beach" project and "Wutao Group 6-14 beach" project were 2 039.40 thousand yuan and 955.00 thousand yuan respectively, and the annual net benefit-cost ratios were 1.09: 1 and 1.07: 1 respectively. The O. hupensis snails could be rapidly eliminated by the water storage and aquaculture, and the economic benefit is obvious, but the wetland ecological protection and flood control safety should be considered in the tidal flats wetlands of islet-beach type area of lower reaches of the Yangtze River.

Natural curiosities of the Bug river valley near Janów Podlaski as a chance of the specialized tourism development

NASA Astrophysics Data System (ADS)

Kusznerczuk, Marta

2009-01-01

This paper presents the most precious natural curiosities of the Bug river valley near Janów Podlaski (between Zaczopki and Gnojno). This area is protected as the landscape park - "Podlasie Bug Water Gap". The natural abiotic elements, among others geomorphological ones significantly conditioning unrepeatable charms of the Bug river valley landscape, are regarded as marginal in many papers concerning the unique values of this valley. The presented natural curiosities are arranged in genetic and chronological order. These main relief elements of the Bug river valley are associated with different morphogenetic processes, i.e. the gap formation, the Bug river metamorphosis and gully erosion. These elements can be a chance of the development of specialised tourism, which will influence the economic mobilization of this undeveloped region.

Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

USGS Publications Warehouse

Reheis, M.C.; Laabs, B.J.C.; Kaufman, D.S.

2009-01-01

Bear Lake, on the Idaho-Utah border, lies in a fault-bounded valley through which the Bear River flows en route to the Great Salt Lake. Surficial deposits in the Bear Lake drainage basin provide a geologic context for interpretation of cores from Bear Lake deposits. In addition to groundwater discharge, Bear Lake received water and sediment from its own small drainage basin and sometimes from the Bear River and its glaciated headwaters. The lake basin interacts with the river in complex ways that are modulated by climatically induced lake-level changes, by the distribution of active Quaternary faults, and by the migration of the river across its fluvial fan north of the present lake. The upper Bear River flows northward for ???150 km from its headwaters in the northwestern Uinta Mountains, generally following the strike of regional Laramide and late Cenozoic structures. These structures likely also control the flow paths of groundwater that feeds Bear Lake, and groundwater-fed streams are the largest source of water when the lake is isolated from the Bear River. The present configuration of the Bear River with respect to Bear Lake Valley may not have been established until the late Pliocene. The absence of Uinta Range-derived quartzites in fluvial gravel on the crest of the Bear Lake Plateau east of Bear Lake suggests that the present headwaters were not part of the drainage basin in the late Tertiary. Newly mapped glacial deposits in the Bear River Range west of Bear Lake indicate several advances of valley glaciers that were probably coeval with glaciations in the Uinta Mountains. Much of the meltwater from these glaciers may have reached Bear Lake via groundwater pathways through infiltration in the karst terrain of the Bear River Range. At times during the Pleistocene, the Bear River flowed into Bear Lake and water level rose to the valley threshold at Nounan narrows. This threshold has been modified by aggradation, downcutting, and tectonics. Maximum lake

Streamflow trends in the Spokane River and tributaries, Spokane Valley/Rathdrum Prairie, Idaho and Washington

USGS Publications Warehouse

Hortness, Jon E.; Covert, John J.

2005-01-01

A clear understanding of the aquifer and river dynamics within the Spokane Valley/Rathdrum Prairie is essential in making proper management decisions concerning ground-water and surface-water appropriations. Management of the Spokane Valley/Rathdrum Prairie aquifer is complicated because of interstate, multi-jurisdictional responsibilities, and by the interaction between ground water and surface water. Kendall?s tau trend analyses were completed on monthly mean (July through December) and annual 7-day low streamflow data for the period 1968?2002 from gaging stations located within the Spokane Valley/Rathdrum Prairie. The analyses detected trends of decreasing monthly mean streamflow at the following gaging stations: Spokane River near Post Falls, Idaho (August and September); Spokane River at Spokane, Washington (September); and Little Spokane River at Dartford, Washington (September and October); and decreasing annual 7-day low streamflows at the following gaging stations: Spokane River near Post Falls, Idaho and Spokane River at Spokane, Washington. Limited analyses of lake-level, precipitation, tributary inflow, temperature, and water-use data provided little insight as to the reason for the decreasing trends in streamflow. A net gain in streamflow occurs between the gaging stations Spokane River near Post Falls, Idaho and Spokane River at Spokane, Washington. Significant streamflow losses occur between the gaging stations Spokane River near Post Falls, Idaho and Spokane River at Greenacres, Washington; most, if not all, of the gains occur downstream from the Greenacres gaging station. Trends of decreasing net streamflow gains in the Spokane River between the near Post Falls and at Spokane gaging stations were detected for the months of September, October, and November.

The distribution of sediments grain size along the depth in source of the Yangtze River, Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Zhou, Y.; Yao, S.; Zhou, S.; Liu, X.; Yan, X.; Lu, J.

2017-12-01

Sediment was the one result of river process, in alluvial rive, it can reflect the hydrodynamic characteristic, even the hydrology and climate. In the source region of the Yangtze River with few human activities, The Qumalai Reach of the Tongtianhe River was selected to research the distribution of sediments grain size along the depth. The vertical drilling tools were used to obtain 7 boreholes along the river cross section, and the sedimentary cores were made analysis of stratification and granularity. The results show: The sediments are dominated by sand and grail, the sediment transport capacity of river sources is strong; the grain size frequency distribution curve with 2 3 kurtosis, main peak is sharp, it is typical deposit sediment of the suspended load; The grain size coarsen from the stream terrace to the main channel, sediment transport capacity of main stream is bigger; There are several coarse and fine sediments layers in the sedimentary core of the terrace and flood plain, medium diameters of each layer are various from 0.4mm to 80mm, different layer with different grain size can reflect the different hydrodynamic characteristic of each historical period. This result can provide the original data and enlightenment to support the research for historical river process and hydrology so much as the climate change.

The Yangtze-Project

NASA Astrophysics Data System (ADS)

Subklew, Günter; Ulrich, Julia; Fürst, Leander; Höltkemeier, Agnes

2010-05-01

As an important element in Chinese politics for the development of the Western parts of the country, a large hydraulic engineering project - the Three Gorges Dam - has been set up in order to dam the Yangtze River for a length of over 600 km with an average width of about 1,100 m. It is expected that this results in ecological, technical and social problems of a magnitude hardly dealt with before. With this gigantic project, the national executive is pursuing the aims of - preventing flooding - safeguarding the water supply - encouraging navigation and - generating electric energy. In future, fluctuations of the water level of up to 30 metres will be deliberately applied in the dammed-up section of the river while retaining the flow character of the seasonal variation. The pollution of the Yangtze with a wide range of problem substances is frequently underestimated since in many cases attention is only paid to the low measured concentrations. However, the large volumes of water lead to appreciable loads and thus the danger of an accumulation of pollutants even reaching the human food chain. It should also not be forgotten that the Yangtze represents the major, and in some cases indeed the only, source of drinking and domestic water for the population. A consideration of the water level in the impoundment that will in future arise from management of the reservoir reveals the dramatic change in contrast to the natural inundation regime. In the past, the flood events on the banks of the Yangtze and its tributaries occurred in the summer months. The plants in the riparian zone (water fluctuation zone = WFZ) were previously inundated during the warmer time of year (28 ° July/August) and the terrestrial phase of the WFZ was characterized by cool temperatures (3-5 °C January) that permitted little plant activity. In future, the highest water levels will occur in winter above the dam on the Yangtze and also on the tributaries flowing into it. The plants in the WFZ will

Petrogenesis of the mafic microgranular enclaves (MMEs) and their host granodiorites from the Zijinshan intrusion along the Middle-Lower Yangtze River Valley: Implications for geodynamic setting and mineralization

NASA Astrophysics Data System (ADS)

Liu, Peng; Mao, Jingwen; Yao, Wei; Wang, Xiaoxia; Jia, Lihui; Yang, Hanwen

2017-09-01

The Zijinshan intrusion is located to the south of the Tongling ore cluster of the Middle-Lower Yangtze River Valley metallogenic belt (YRB) and even south to the Yangxing-Changzhou Fault (YCF), which separates the YRB and the Jiangnan Massif. It is an I-type high-K calc-alkaline granodiorite with abundant MMEs. Zircon LA-MC-ICP-MS U-Pb ages of 144.0 ± 1.0 Ma and 142.5 ± 1.0 Ma for the host granodiorite and MMEs indicate coeval formation. Biotites from the host granodiorites and MMEs have similar composition, with low FeOt/(FeOt + MgO) values of 0.60-0.65 and 0.60-0.65, and high MgO contents of 10.51-11.70 wt.% and 10.89-12.37 wt.%, respectively. All the biotite samples are between the NNO and the MH buffers. The host granodiorites are metaluminous (A/CNK = 0.94-0.95), enriched in Cs, Rb, U and Pb, depleted in Ba, Sr, Nb, Zr, P, and Ti, with moderate negative Eu anomalies of 0.80-0.87, (87Sr/86Sr)i of 0.70874 to 0.70887, εNd(t) of - 5.63 to - 5.36 and εHf(t) of - 8.68 to - 2.76. The MMEs have lower SiO2 and higher K2O, and they are also enriched in Cs, Rb, U, Ta and Pb, and depleted in Ba, Sr, Nb, Zr, P and Ti, with (87Sr/86Sr)i of 0.70889 to 0.70927, εNd(t) of - 5.52 to - 5.20 and εHf(t) of - 6.46 to - 3.59. All these characteristics demonstrate that partial melting of both the lower crust and an enriched lithospheric mantle metasomatized by subducted slab fluid and their subsequent mixing led to the origin of the I-type granodiorite magmas of the Zijinshan intrusion, which took place in the geodynamic context of the subduction of the Izanagi plate. Combined with the field investigations, we suggest that the Zijinshan intrusion has potential for porphyry Cu-Au mineralization and the Cu-Au metallogenic belt of the YRB may have extended to the south of the YCF.

Development of emissions inventory and identification of sources for priority control in the middle reaches of Yangtze River Urban Agglomerations.

PubMed

Sun, Xiaowei; Cheng, Shuiyuan; Lang, Jianlei; Ren, Zhenhai; Sun, Chao

2018-06-01

This paper presents the first attempt to investigate the emission source control of the Middle Reaches of Yangtze River Urban Agglomerations (MRYRUA), one of the national urban agglomerations in China. An emission inventory of the MRYRUA was developed as inputs to the CAMx model based on county-level activity data obtained by full-coverage investigation and source-based spatial surrogates. A classification technology method for priority control of atmospheric emission sources was introduced and applied in the MRYRUA for the evaluation of the emission sources control on the region-scale and city-scale, respectively. The results demonstrated that the emission sources in the Hefei-centered urban agglomerations contributed the biggest on the mean PM 2.5 concentrations of the MRYRUA and should be taken the priority to control. The emission sources in the Ma'anshan city, Xiangtan city, Hefei city and Wuhan city were the bigger contributors on the mean PM 2.5 concentrations of the MRYRUA among the cities and should be taken the priority to control. In generally, emission sources in cities along the Yangtze River and the tributary should be given the special attention for the regional air quality target attainments. This study can give an understanding of Chinese emissions and provide a valuable preference to policy makers for finding effective mitigation measures and control strategies for reducing national and regional air pollution in China. Copyright © 2017 Elsevier B.V. All rights reserved.

Estimation of salt loads for the Dolores River in the Paradox Valley, Colorado, 1980–2015

USGS Publications Warehouse

Mast, M. Alisa

2017-07-13

Regression models that relate total dissolved solids (TDS) concentrations to specific conductance were used to estimate salt loads for two sites on the Dolores River in the Paradox Valley in western Colorado. The salt-load estimates will be used by the Bureau of Reclamation to evaluate salt loading to the river coming from the Paradox Valley and the effect of the Paradox Valley Unit (PVU), a project designed to reduce the salinity of the Colorado River. A second-order polynomial provided the best fit of the discrete data for both sites on the river. The largest bias occurred in samples with elevated sulfate concentrations (greater than 500 milligrams per liter), which were associated with short-duration runoff events in late summer and fall. Comparison of regression models from a period of time before operation began at the PVU and three periods after operation began suggests the relation between TDS and specific conductance has not changed over time. Net salt gain through the Paradox Valley was estimated as the TDS load at the downstream site minus the load at the upstream site. The mean annual salt gain was 137,900 tons per year prior to operation of the PVU (1980–1993) and 43,300 tons per year after the PVU began operation (1997–2015). The difference in annual salt gain in the river between the pre-PVU and post-PVU periods was 94,600 tons per year, which represents a nearly 70 percent reduction in salt loading to the river.

Distribution and risk assessment of trace metals in sediments from Yangtze River estuary and Hangzhou Bay, China.

PubMed

Li, Feipeng; Mao, Lingchen; Jia, Yubao; Gu, Zhujun; Shi, Weiling; Chen, Ling; Ye, Hua

2018-01-01

The Yangtze River estuary (YRE) and Hangzhou Bay (HZB) is of environmental significance because of the negative impact from industrial activities and rapid development of aquaculture on the south bank of HZB (SHZB) in recent years. This study investigated the distribution and risk assessments of trace metals (Cr, Cu, Zn, Hg, Pb, and Cd) accumulated in surface sediments by sampling in YRE, outer and south HZB. Copper and Zn concentration (avg. 35.4 and 98.7 mg kg -1 , respectively) in surface sediments were generally higher than the background suggesting a widespread of Cu and Zn in the coastal area of Yangtze River Delta. High concentrations of Cu (~ 42 mg kg -1 ), Zn (~ 111 mg kg -1 ), Cd (~ 0.27 mg kg -1 ), and Hg (~ 0.047 mg kg -1 ) were found in inner estuary of YRE and decreased offshore as a result of terrestrial input and dilution effect of total metal contents by "cleaner" sediments from the adjacent sea. In outer HZB, accumulation of terrestrial derived metal has taken place near the Zhoushan Islands. Increase in sediment metal concentration from the west (inner) to the east (outer) of SHZB gave rise to the input of fine-grained sediments contaminated with metals from outer bay. According the results from geoaccumulation index, nearly 75% of samples from YRE were moderately polluted (1.0 < I geo  < 2.0) by Cd. Cadmium and Hg contributed for 80~90% to the potential ecological risk index in the YRE and HZB, with ~ 72% sites in HZB under moderate risk (150 ≤ RI < 300) especially near Zhoushan Islands.

Comparison of plant cover of river valley fragments by using GIS tools and multivariate analysis

NASA Astrophysics Data System (ADS)

Waldon-Rudzionek, Barbara

2017-11-01

Selected landscape registers and results of ecological analyses of flora used in studies of transformations of anthropogenic plant cover and river valley landscapes were presented. The results were shown pursuant to a comparison of fragments of two adjacent valleys in north-western Poland.

Middle Pleistocene infill of Hinkley Valley by Mojave River sediment and associated lake sediment: Depositional architecture and deformation by strike-slip faults

USGS Publications Warehouse

Miller, David; Haddon, Elizabeth; Langenheim, Victoria; Cyr, Andrew J.; Wan, Elmira; Walkup, Laura; Starratt, Scott W.

2018-01-01

Hinkley Valley in the Mojave Desert, near Barstow about 140 km northeast of Los Angeles and midway between Victorville Valley and the Lake Manix basin, contains a thick sedimentary sequence delivered by the Mojave River. Our study of sediment cores drilled in the valley indicates that Hinkley Valley was probably a closed playa basin with stream inflow from four directions prior to Mojave River inflow. The Mojave River deposited thick and laterally extensive clastic wedges originating from the southern valley that rapidly filled much of Hinkley Valley. Sedimentary facies representing braided stream, wetland, delta, and lacustrine depositional environments all are found in the basin fill; in some places, the sequence is greater than 74 m (245 ft) thick. The sediment is dated in part by the presence of the ~631 ka Lava Creek B ash bed low in the section, and thus represents sediment deposition after Victorville basin was overtopped by sediment and before the Manix basin began to be filled. Evidently, upstream Victorville basin filled with sediment by about 650 ka, causing the ancestral Mojave River to spill to the Harper and Hinkley basins, and later to Manix basin.Initial river sediment overran wetland deposits in many places in southern Hinkley Valley, indicating a rapidly encroaching river system. These sediments were succeeded by a widespread lake (“blue” clay) that includes the Lava Creek B ash bed. Above the lake sediment lies a thick section of interlayered stream sediment, delta and nearshore lake sediment, mudflat and/or playa sediment, and minor lake sediment. This stratigraphic architecture is found throughout the valley, and positions of lake sediment layers indicate a successive northward progression in the closed basin. A thin overlapping sequence at the north end of the valley contains evidence for a younger late Pleistocene lake episode. This late lake episode, and bracketing braided stream deposits of the Mojave River, indicate that the river

Manual of Military Decorations and Awards: DoD-Wide Performance and Valor Awards; Foreign Awards; Military Awards to Foreign Personnel and U.S. Public Health Service Officers; and Miscellaneous Information

DTIC Science & Technology

2010-11-23

Indies Campaign Medal Women’s Army Corps Service Medal World War II Victory Medal Yangtze Service Medal Table 3. Foreign Awards Awarded...Philippine Islands who served on active duty at any time between December 7, 1941, and December 31, 1946. (45) Yangtze Service Medal. Department of...operations in the Yangtze River Valley, China, between September 3, 1926, and October 21, 1927, and between March 1, 1930, and December 31, 1932

Asian Carp Survivability Experiments and Water Transport Surveys in the Illinois River. Volume 2

DTIC Science & Technology

2013-01-01

Reference 3)) have documented the egg and larval stages of grass, black, silver and bighead carps in the Yangtze River. This early paper also reported...rates at controlled tempera- tures to better understand the early egg and larval stages of silver and bighead carp. In the Yangtze River, after the...translated by Duane Chapman 2006, Gezhouba Water Control Project and four famous fishes in Yangtze River, Hubei Science and Technology Press, Wuhan

Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

USGS Publications Warehouse

Bartolino, James R.

2009-01-01

The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Haley, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system which consists of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on ground water for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the ground-water resource. To help address these concerns this report describes a ground-water budget developed for the Wood River Valley aquifer system for three selected time periods: average conditions for the 10-year period 1995-2004, and the single years of 1995 and 2001. The 10-year period 1995-2004 represents a range of conditions in the recent past for which measured data exist. Water years 1995 and 2001 represent the wettest and driest years, respectively, within the 10-year period based on precipitation at the Ketchum Ranger Station. Recharge or inflow to the Wood River Valley aquifer system occurs through seven main sources (from largest to smallest): infiltration from tributary canyons, streamflow loss from the Big Wood River, areal recharge from precipitation and applied irrigation water, seepage from canals and recharge pits, leakage from municipal pipes, percolation from septic systems, and subsurface inflow beneath the Big Wood River in the northern end of the valley. Total estimated mean annual inflow or recharge to the aquifer system for 1995-2004 is 270,000 acre-ft/yr (370 ft3/s). Total recharge for the wet year 1995 and the dry year 2001 is estimated to be 270,000 acre-ft/yr (370 ft3/s) and 220,000 acre-ft/yr (300 ft3/s), respectively. Discharge or outflow from the Wood River Valley aquifer system occurs through

Monitoring of heavy flooding by orbital remote sensing: The example of the Doce river valley. [Doce River Valley, Brazil

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Novo, E. M. L. D.; Dossantos, A. P.

1981-01-01

The application of temporal LANDSAT data to study floods was verified, and the natural features responsible for this phenomenon were surveyed using the Doce river valley as a test site, because of the catastrophic (1978-1979) flood. Data from LANDSAT images and CCT's were used. Geomorphical mapping evaluated morphostructural features. Seven and nine classes of water surfaces for dry and rainy seasons were analyzed. The magnitude of the changes from preflood to postflood stage are estimated. The single Pixel program was applied to correlate the drainage basin characteristics to the grey level of LANDSAT data.

Semi-volatile organic compounds and trace elements in the Yangtze River source of drinking water.

PubMed

Wu, Bing; Zhang, Xuxiang; Zhang, Xiaolin; Yasun, Aishangjiang; Zhang, Yan; Zhao, Dayong; Ford, Tim; Cheng, Shupei

2009-08-01

Determination of 24 semi-volatile organic compounds (SVOCs) and 24 trace elements in water samples was conducted in order to investigate the quality of the Nanjing source of drinking water taken from Yangtze River. The total concentrations of SVOCs and trace elements were in the range of 1,951-11,098 ng/l and 51,274-72,384 microg/l, respectively. No significant seasonal changes were found for the pollutants' concentrations. A primary health risk assessment was carried out to evaluate potential health effects. Risk quotients involving carcinogenic effects for benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenz(a,h)anthracene, bis(2-ethylhexyl)phthalate and arsenic were >1 under the worst-case scenario. The results of this study demonstrate the importance of further studies on the environmental health effects of exposure to the source water.

Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses

USGS Publications Warehouse

Knott, J.R.; Machette, M.N.; Klinger, R.E.; Sarna-Wojcicki, A. M.; Liddicoat, J.C.; Tinsley, J. C.; David, B.T.; Ebbs, V.M.

2008-01-01

During glacial (pluvial) climatic periods, Death Valley is hypothesized to have episodically been the terminus for the Amargosa, Owens, and Mojave Rivers. Geological and biological studies have tended to support this hypothesis and a hydrological link that included the Colorado River, allowing dispersal of pupfish throughout southeastern California and western Nevada. Recent mitochondrial deoxyribonucleic acid (mtDNA) studies show a common pupfish (Cyprinodontidae) ancestry in this region with divergence beginning 3-2 Ma. We present tephrochronologic and paleomagnetic data in the context of testing the paleohydrologic connections with respect to the common collection point of the Amargosa, Owens, and Mojave Rivers in Death during successive time periods: (1) the late Pliocene to early Pleistocene (3-2 Ma), (2) early to middle Pleistocene (1.2-0.5 Ma), and (3) middle to late Pleistocene (<0.70.03 Ma; paleolakes Manly and Mojave). Using the 3.35 Ma Zabriskie Wash tuff and 3.28 Ma Nomlaki Tuff Member of the Tuscan and Tehama Formations, which are prominent marker beds in the region, we conclude that at 3-2 Ma, a narrow lake occupied the ancient Furnace Creek Basin and that Death Valley was not hydrologically connected with the Amargosa or Mojave Rivers. A paucity of data for Panamint Valley does not allow us to evaluate an Owens River connection to Death Valley ca. 3-2 Ma. Studies by others have shown that Death Valley was not hydrologically linked to the Amargosa, Owens, or Mojave Rivers from 1.2 to 0.5 Ma. We found no evidence that Lake Manly flooded back up the Mojave River to pluvial Lake Mojave between 0.18 and 0.12 Ma, although surface water flowed from the Amargosa and Owens Rivers to Death Valley at this time. There is also no evidence for a connection of the Owens, Amargosa, or Mojave Rivers to the Colorado River in the last 3-2 m.y. Therefore, the hypothesis that pupfish dispersed or were isolated in basins throughout southeastern California and western

Impact of a large flood on mountain river habitats, channel morphology, and valley infrastructure

NASA Astrophysics Data System (ADS)

Hajdukiewicz, Hanna; Wyżga, Bartłomiej; Mikuś, Paweł; Zawiejska, Joanna; Radecki-Pawlik, Artur

2016-11-01

The Biała River, Polish Carpathians, was considerably modified by channelization and channel incision in the twentieth century. To restore the Biała, establishing an erodible corridor was proposed in two river sections located in its mountain and foothill course. In these sections, longer, unmanaged channel reaches alternate with short, channelized reaches; and channel narrowing and incision increases in the downstream direction. In June 2010 an 80-year flood occurred on the river; and this study aims at determining its effects on physical habitat conditions for river biota, channel morphology, and valley-floor infrastructure. Surveys of 10 pairs of closely located, unmanaged and channelized cross sections, performed in 2009 and in the late summer 2010, allowed us to assess the flood-induced changes to physical habitat conditions. A comparison of channel planforms determined before (2009) and after (2012) the flood provided information on the degree of channel widening as well as changes in the width of particular elements of the river's active zone in eight stretches of the Biała. The impact of the flood on valley-floor infrastructure was confronted with the degree of river widening in unmanaged and channelized river reaches. Before the flood, unmanaged cross sections were typified by finer bed material and greater lateral variability in depth-averaged and near-bed flow velocity than channelized cross sections. The flood tended to equalize habitat conditions in both types of river cross sections, obliterating differences (in particular physical habitat parameters) between channelized and unmanaged channel reaches. River widening mostly reflected an increase in the area of channel bars, whereas the widening of low-flow channels was less pronounced. A comparison of channel planform from 2009 and 2012 indicated that intense channel incision typical of downstream sections limited river widening by the flood. Active channel width increased by half in the unmanaged

Determining the contributions of urbanisation and climate change to NPP variations over the last decade in the Yangtze River Delta, China.

PubMed

Wu, Shaohua; Zhou, Shenglu; Chen, Dongxiang; Wei, Zongqiang; Dai, Liang; Li, Xingong

2014-02-15

Terrestrial net primary production (NPP) is an important measure of global change, and identifying the relative contributions of urbanisation and climate change to NPP is important for understanding the impact of human and natural influences on terrestrial systems and the carbon cycle. The objective of this study was to reveal how urbanisation and climate drive changes in NPP. Satellite-based estimates of NPP collected over a 12-year period (1999-2010) were analysed to identify NPP variations in the Yangtze River Delta. Temporal and spatial analysis methods were used to identify the relationships among NPP, nighttime light urbanisation index values, and climatic factors from pixel to regional scales. The NPP of the entire Yangtze River Delta decreased slightly at a rate of -0.5 g C m(-2)a(-1) from 1999 to 2010, but this change was not significant. However, in the urban region, NPP decreased significantly (p<0.05) at a rate of -4.7 g C m(-2)a(-1) due to urbanisation processes. A spatially explicit method was proposed to partition the relative contributions of urbanisation and climate change to NPP variation. The results revealed that the urbanisation factor is the main driving force for NPP change in high-speed urbanisation areas, and the factor accounted for 47% of the variations. However, in the forest and farm regions, the NPP variation was mainly controlled by climate change and residual factors. Copyright © 2013 Elsevier B.V. All rights reserved.

Don't Fence Me In: Free Meanders in a Confined River Valley

NASA Astrophysics Data System (ADS)

Eke, E. C.; Wilcock, P. R.

2015-12-01

The interaction between meandering river channels and inerodible valley walls provides a useful test of our ability to understand meander dynamics. In some cases, river meanders confined between valley walls display distinctive angular bends in a dynamic equilibrium such that their size and shape persist as the meander migrates. In other cases, meander geometry is more varied and changes as the meander migrates. The ratio of channel to valley width has been identified as a useful parameter for defining confined meanders, but is not sufficient to distinguish cases in which sharp angular bends are able to migrate with little change in geometry. Here, we examine the effect of water and sediment supply on the geometry of confined rivers in order to identify conditions under which meander geometry reaches a persistent dynamic equilibrium. Because channel width and meander geometry are closely related, we use a numerical meander model that allows for independent migration of both banks, thereby allowing channel width to vary in space and time. We hypothesize that confined meanders with persistent angular bends have smaller transport rates of bed material and that their migration is driven by erosion of the cutbank (bank-pull migration). When bed material supply is sufficiently large that point bar deposition drives meander migration (bar-push migration), confined meander bends have a larger radius of curvature and a geometry that varies as the meander migrates. We test this hypothesis using historical patterns of confined meander migration for rivers with different rates of sediment supply and bed material transport. Interpretation of the meander migration pattern is provided by the free-width meander migration model.

OSL dating of fine-grained quartz from Holocene Yangtze delta sediments

NASA Astrophysics Data System (ADS)

Sugisaki, S.; Buylaert, J. P.; Murray, A. S.; Tada, R.; Zheng, H.; Ke, W.; Saito, K.; Irino, T.; Chao, L.; Shiyi, L.; Uchida, M.

2014-12-01

Flood events in the Yangtze River are associated with variation in East Asian Summer Monsoon (EASM) precipitation. Understanding the frequency and scale of the EASM precipitation during the Holocene is a key to understanding the mechanism and cyclicity of floods and droughts. Because about 70% of the annual discharge occurs during the flood season, the Yangtze delta sediments provide a good archive of EASM precipitation. In this study, we investigate the possibility of applying OSL dating to establishing high-resolution chronologies for the Yangtze delta sediment cores YD13-1H and G3. The objectives of this study are: (1) test whether fine grained quartz in present day suspended particle matter (SPM) is fully bleached or reset before deposition, (2) where possible, test quartz fine- and coarse-grain OSL dating against radiocarbon shell ages, (3) interpret the sediment transport processes through the differential bleaching of quartz and feldspar OSL signals. We show that the SPM collected from the surface water column of the Yangtze River during the flood season is well-bleached (offset ~60 years). Fine-grained pro-delta sediments are thus potentially a good dosimeter for OSL dating. OSL ages sediment cores indicate a pronounced change in sedimentation rate at ~6 ka and ~2ka. These events are consistent with what is known of the evolution of the Yangtze catchment and delta. The delta began to build at ~6 ka (Zhao et al., 1979), and human activities increased significantly in the catchment at ~2ka　(Chen et al., 1985). It is however surprising that the entire top 9 m of sediment only records these two events. The question of whether significant deposition was limited to 2 ka and 6 ka, or whether the record has been disturbed by erosion/reworking remains. These issues are discussed in terms of the reliability of the quartz OSL ages, the degree of bleaching by comparison with polymineral OSL signals, and the relationship of the OSL ages to the sedimentary record.

Depth to water, 1991, in the Rathdrum Prairie, Idaho; Spokane River valley, Washington; Moscow-Lewiston-Grangeville area, Idaho; and selected intermontane valleys, east-central Idaho

USGS Publications Warehouse

Berenbrock, Charles E.; Bassick, M.D.; Rogers, T.L.; Garcia, S.P.

1995-01-01

This map report illustrates digitally generated depth-to-water zones for the Rathdrum Prairie in Idaho; part of the Spokane River Valley in eastern Washington; and the intermontane valleys of the upper Big Wood, Big Lost, Pahsimeroi, Little Lost, and Lemhi Rivers and Birch Creek in Idaho. Depth to water is 400 to 500 feet below land surface in the northern part of Rathdrum Prairie, 100 to 200 feet below land surface at the Idaho-Washington State line, and 0 to 250 feet below land surface in the Spokane area. Depth to water in the intermontane valleys in east-central Idaho is least (usually less than 50 feet) near streams and increases toward valley margins where mountain-front alluvial fans have formed. Depths to water shown in the Moscow-Lewiston-Grangeville area in Idaho are limited to point data at individual wells because most of the water levels measured were not representative of levels in the uppermost aquifer but of levels in deeper aquifers.

The characteristics changes of pH and EC of atmospheric precipitation and analysis on the source of acid rain in the source area of the Yangtze River from 2010 to 2015

NASA Astrophysics Data System (ADS)

Zong-Jie, Li; Song, Ling-Ling; Jing-zhu, Ma; Li, Yong-ge

2017-05-01

Through the analysis of pH value, EC, precipitation and wind speed of 402 precipitation samples in the source region of the Yangtze River from January 1, 2010 to December 31, 2015, especially for the analysis of the 14 acid rain events. The results showed that: the acid rain in the source region of the Yangtze River was mainly affected by the southwest monsoon and the westerly circulation. The occurrence of acid rain mainly controlled by industrial pollution and other pollutants coming from India and other surrounding areas. And the other cause was that because of the Qinghai Tibet highway and the Qinghai Tibet railway, there were a lot of cars coming and going. And there were people in the summer to plateau tourism increased year by year, and more for self-driving travelling. This added additional pollutants (automobile exhaust) for the source of the Yangtze River. During the period of sampling, the variation range of pH value was from 4.0 to 8.57, with the mean was 6.37. And the range of EC was from 5.2 to 124.4 μs/cm, the average was 27.59 μs/cm. The order of conductivity in the four seasons was Spring > Winter > Summer > Autumn. And the order of pH in four seasons was Summer > Spring = Winter > Autumn. The results are also helpful for further understanding the acid rain in the Tibetan Plateau and providing scientific basis for the effective prevention and control of acid rain.

D GIS for Flood Modelling in River Valleys

NASA Astrophysics Data System (ADS)

Tymkow, P.; Karpina, M.; Borkowski, A.

2016-06-01

The objective of this study is implementation of system architecture for collecting and analysing data as well as visualizing results for hydrodynamic modelling of flood flows in river valleys using remote sensing methods, tree-dimensional geometry of spatial objects and GPU multithread processing. The proposed solution includes: spatial data acquisition segment, data processing and transformation, mathematical modelling of flow phenomena and results visualization. Data acquisition segment was based on aerial laser scanning supplemented by images in visible range. Vector data creation was based on automatic and semiautomatic algorithms of DTM and 3D spatial features modelling. Algorithms for buildings and vegetation geometry modelling were proposed or adopted from literature. The implementation of the framework was designed as modular software using open specifications and partially reusing open source projects. The database structure for gathering and sharing vector data, including flood modelling results, was created using PostgreSQL. For the internal structure of feature classes of spatial objects in a database, the CityGML standard was used. For the hydrodynamic modelling the solutions of Navier-Stokes equations in two-dimensional version was implemented. Visualization of geospatial data and flow model results was transferred to the client side application. This gave the independence from server hardware platform. A real-world case in Poland, which is a part of Widawa River valley near Wroclaw city, was selected to demonstrate the applicability of proposed system.

Holocene intramontane lake development: A new model in the Jáchal River Valley, Andean Precordillera, San Juan, Argentina

NASA Astrophysics Data System (ADS)

Colombo, Ferran; Busquets, Pere; Sole de Porta, Nuria; Limarino, Carlos Oscar; Heredia, Nemesio; Rodriguez-Fernandez, Luis Roberto; Alvarez-Marron, Joaquina

2009-10-01

The Jáchal River Valley displays a number of significant Holocene sedimentary accumulations made up of fine-grained materials. These deposits are interpreted as the sedimentary infill of shallow temporary lakes that were generated by slow growing episodes of alluvial fans that obstructed the Jáchal River Valley. The association of fossil remains through the Holocene sedimentary sequence suggests that the accumulation of lacustrine sediments was affected by climate variations. The predominant aridity was punctuated by very few humid episodes characterised by fresh-water gastropoda and the intercalations of muddy sediments. The high proportion of charcoal particles in some samples indicates periodic forest fires. Abundant non-pollen forest remains suggest that an open zone dominated by several types of grasses underwent a dry season during part of the year. The palynomorph associations found in the Jáchal River Valley Holocene lacustrine sediments suggest that the humid conditions were less intense than those in the San Juan River Valley located more than one hundred kilometres southwards. Our study suggests that lake formation could have been controlled by climate oscillation probably related to the ENSO variation at 30° south latitude.

Conservation genetics of the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi): River valleys are critical features for snakes at northern range limits

PubMed Central

Graham, Carly F.; Martino, Jessica A.; Frasier, Timothy R.; Lance, Stacey L.; Gardiner, Laura E.; Poulin, Ray G.

2017-01-01

On the North American Great Plains, several snake species reach their northern range limit where they rely on sparsely distributed hibernacula located in major river valleys. Independent colonization histories for the river valleys and barriers to gene flow caused by the lack of suitable habitat between them may have produced genetically differentiated snake populations. To test this hypothesis, we used 10 microsatellite loci to examine the population structure of two species of conservation concern in Canada: the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi) in 3 major river valleys in southern Saskatchewan. Fixation indices (FST) showed that populations in river valleys were significantly differentiated for both species (racers, FST = 0.096, P = 0.001; bullsnakes FST = 0.045–0.157, P = 0.001). Bayesian assignment (STRUCTURE) and ordination (DAPC) strongly supported genetically differentiated groups in the geographically distinct river valleys. Finer-scale subdivision of populations within river valleys was not apparent based on our data, but is a topic that should be investigated further. Our findings highlight the importance of major river valleys for snakes at the northern extent of their ranges, and raise the possibility that populations in each river valley may warrant separate management strategies. PMID:29095863

Conservation genetics of the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi): River valleys are critical features for snakes at northern range limits.

PubMed

Somers, Christopher M; Graham, Carly F; Martino, Jessica A; Frasier, Timothy R; Lance, Stacey L; Gardiner, Laura E; Poulin, Ray G

2017-01-01

On the North American Great Plains, several snake species reach their northern range limit where they rely on sparsely distributed hibernacula located in major river valleys. Independent colonization histories for the river valleys and barriers to gene flow caused by the lack of suitable habitat between them may have produced genetically differentiated snake populations. To test this hypothesis, we used 10 microsatellite loci to examine the population structure of two species of conservation concern in Canada: the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi) in 3 major river valleys in southern Saskatchewan. Fixation indices (FST) showed that populations in river valleys were significantly differentiated for both species (racers, FST = 0.096, P = 0.001; bullsnakes FST = 0.045-0.157, P = 0.001). Bayesian assignment (STRUCTURE) and ordination (DAPC) strongly supported genetically differentiated groups in the geographically distinct river valleys. Finer-scale subdivision of populations within river valleys was not apparent based on our data, but is a topic that should be investigated further. Our findings highlight the importance of major river valleys for snakes at the northern extent of their ranges, and raise the possibility that populations in each river valley may warrant separate management strategies.

Quaternary landscape evolution of tectonically active intermontane basins: the case of the Middle Aterno River Valley (Abruzzo, Central Italy)

NASA Astrophysics Data System (ADS)

Falcucci, Emanuela; Gori, Stefano; Della Seta, Marta; Fubelli, Giandomenico; Fredi, Paola

2014-05-01

The Middle Aterno River Valley is characterised by different Quaternary tectonic depressions localised along the present course of the Aterno River (Central Apennine) .This valley includes the L'Aquila and Paganica-Castelnuovo-San Demetrio tectonic basins, to the North, the Middle Aterno Valley and the Subequana tectonic basin, to the South. The aim of this contribution is to improve the knowledge about the Quaternary geomorphological and tectonic evolution of this portion of the Apennine chain. A synchronous lacustrine depositional phase is recognized in all these basins and attributed to the Early Pleistocene by Falcucci et al. (2012). At that time, this sector of the chain showed four distinct closed basins, hydrologically separated from each other and from the Sulmona depression. This depression, actually a tectonic basin too, was localized South of the Middle Aterno River Valley and it was drained by an endorheic hydrographic network. The formation of these basins was due to the activity of different fault systems, namely the Upper Aterno River Valley-Paganica system and San Pio delle Camere fault, to the North, and the Middle Aterno River Valley-Subequana Valley fault system to the South. These tectonic structures were responsible for the origin of local depocentres inside the depressions which hosted the lacustrine basins. Ongoing surveys in the uppermost sectors of the Middle Aterno River Valley revealed the presence of sub-horizontal erosional surfaces that are carved onto the carbonate bedrock and suspended several hundreds of metres over the present thalweg. Gently dipping slope breccias referred to the Early Pleistocene rest on these surfaces, thus suggesting the presence of an ancient low-gradient landscape adjusting to the local base level.. Subsequently, this ancient low relief landscape underwent a strong erosional phase during the Middle Pleistocene. This erosional phase is testified by the occurrence of valley entrenchment and of coeval fluvial

Risk Assessment on Dietary Exposure to Aflatoxin B1 in Post-Harvest Peanuts in the Yangtze River Ecological Region

PubMed Central

Ding, Xiaoxia; Wu, Linxia; Li, Peiwu; Zhang, Zhaowei; Zhou, Haiyan; Bai, Yizhen; Chen, Xiaomei; Jiang, Jun

2015-01-01

Based on the 2983 peanut samples from 122 counties in six provinces of China’s Yangtze River ecological region collected between 2009–2014, along with the dietary consumption data in Chinese resident nutrition and health survey reports from 2002 and 2004, dietary aflatoxin exposure and percentiles in the corresponding statistics were calculated by non-parametric probability assessment, Monte Carlo simulation and bootstrap sampling methods. Average climatic conditions in the Yangtze River ecological region were calculated based on the data from 118 weather stations via the Thiessen polygon method. The survey results found that the aflatoxin contamination of peanuts was significantly high in 2013. The determination coefficient (R2) of multiple regression reflected by the aflatoxin B1 content with average precipitation and mean temperature in different periods showed that climatic conditions one month before harvest had the strongest impact on aflatoxin B1 contamination, and that Hunan and Jiangxi provinces were greatly influenced. The simulated mean aflatoxin B1 intake from peanuts at the mean peanut consumption level was 0.777–0.790 and 0.343–0.349 ng/(kg·d) for children aged 2–6 and standard adults respectively. Moreover, the evaluated cancer risks were 0.024 and 0.011/(100,000 persons·year) respectively, generally less than China’s current liver cancer incidence of 24.6 cases/(100,000 persons·year). In general, the dietary risk caused by peanut production and harvest was low. Further studies would focus on the impacts of peanut circulation and storage on aflatoxin B1 contamination risk assessment in order to protect peanut consumers’ safety and boost international trade. PMID:26501322

Pollution status of polycyclic aromatic hydrocarbons in surface sediments from the Yangtze River Estuary and its adjacent coastal zone.

PubMed

Wang, Chenglong; Zou, Xinqing; Gao, Jianhua; Zhao, Yifei; Yu, Wenwen; Li, Yali; Song, Qiaochu

2016-11-01

Polycyclic aromatic hydrocarbons (PAHs) are mainly produced by incomplete combustion and are used as indicators of anthropogenic activities on the environment. This study analyses the PAHs level in the Yangtze River Estuary (YRE), an important component of Yangtze River and a developed and populated region in China. Surface sediments were collected from 77 sites at the YRE and its adjacent coastal zone (IACZ) for a comprehensive study of PAHs. Kriging interpolation technology and Positive matrix factorization (PMF) model were applied to explore the spatial distribution and sources of PAHs. Concentrations of 16 PAHs (ΣPAHs) varied from 27.2 ng g(-1) to 621.6 ng g(-1) dry weight, with an average value of 158.2 ng g(-1). Spatially, ΣPAHs exhibited wide fluctuation and exhibited an increasing tendency from north to south. In addition, ΣPAHs exhibited a decreasing trend with increasing distance between the estuary and IACZ. The deposition flux of PAHs indicated that more than 107.8 t a(-1) PAHs was deposited in the study area annually. The results of the PMF model revealed that anthropogenic activities were the main sources of PAHs in the study area. Vehicle emissions and marine engines were the most important sources and accounted for 40.9% of the pollution. Coal combustion, petrogenic sources, and wood combustion were other sources that contributed 23.9%, 23.6%, and 11.5%, respectively. The distribution patterns of PAHs in the YRE and IACZ were influenced by many complicated factors such as sediment grain size, hydrodynamics and so on. Copyright © 2016 Elsevier Ltd. All rights reserved.

Middle Holocene marine flooding and human response in the south Yangtze coastal plain, East China

NASA Astrophysics Data System (ADS)

Wang, Zhanghua; Ryves, David B.; Lei, Shao; Nian, Xiaomei; Lv, Ye; Tang, Liang; Wang, Long; Wang, Jiehua; Chen, Jie

2018-05-01

Coastal flooding catastrophes have affected human societies on coastal plains around the world on several occasions in the past, and are threatening 21st century societies under global warming and sea-level rise. However, the role of coastal flooding in the interruption of the Neolithic Liangzhu culture in the lower Yangtze valley, East China coast has been long contested. In this study, we used a well-dated Neolithic site (the Yushan site) close to the present coastline to demonstrate a marine drowning event at the terminal stage of the Liangzhu culture and discuss its linkage to relative sea-level rise. We analysed sedimentology, chronology, organic elemental composition, diatoms and dinoflagellate cysts for several typical profiles at the Yushan site. The field and sedimentary data provided clear evidence of a palaeo-typhoon event that overwhelmed the Yushan site at ∼2560 BCE, which heralded a period of marine inundation and ecological deterioration at the site. We also infer an acceleration in sea-level rise at 2560-2440 BCE from the sedimentary records at Yushan, which explains the widespread signatures of coastal flooding across the south Yangtze coastal plain at that time. The timing of this mid-Holocene coastal flooding coincided with the sudden disappearance of the advanced and widespread Liangzhu culture along the lower Yangtze valley. We infer that extreme events and flooding accompanying accelerated sea-level rise were major causes of vulnerability for prehistoric coastal societies.

West Harlem Walk (Hudson River Valley Greenway) beneath Henry Hudson ...

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

West Harlem Walk (Hudson River Valley Greenway) beneath Henry Hudson Parkway (HHP) Viaduct at West 155th Street vicinity, with Palisades, George Washington Bridge, and Little Red Lighthouse (visible to left of bridge tower) in background, looking northeast. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

Ground-water flow and simulated effects of development in Paradise Valley, a basin tributary to the Humboldt River in Humboldt County, Nevada

USGS Publications Warehouse

Prudic, David E.; Herman, M.E.

1996-01-01

A computer model was used to characterize ground-water flow in Paradise Valley, Nevada, and to evaluate probable long-term effects of five hypothetical development scenarios. One finding of the study is that concentrating pumping at the south end of Paradise Valley may increase underflow from the adjacent Humboldt River valley, and might affect flow in the river.

Changes in river discharge and hydrograph separation in the upper basins of Yangtze and Yellow Rivers on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Ding, Y.

2017-12-01

Systematic changes of river discharge and the concentration-discharge relation were explored to elucidate the response of river discharge to climate change as well as the connectivity of hydrologic and hydrochemical processes using hydrological data during 1956-2015 and chemical data during 2013-2015 at Yanshiping (YSP, 4,538 km2), Tuotuohe (TTH, 15,924 km2) and Zhimenda (ZMD, 137,704 km2) gauging sections in the upper basin of Yangtze River (UBYA), and at Huangheyan (HHY, 20,930 km2), Jimai (JM, 45,019 km2), Jungong (JG, 98,414 km2) and Tangnaihai (TNH, 121,972 km2) gauging sections in the upper basin of Yellow River (UBYE) on the Tibetan Plateau (TP). Results showed that annual discharge in UBYA presents a decreasing trend from 1950s to late 1970s and exhibits an increasing trend since 1970s due to increased temperature and precipitation. However, discharge in UBYE increases from 1950s to 1980s and decrease since late 1980s due to increased temperature and decreased precipitation. Snow/ice meltwater may play an important role on changes in river discharge from the most upper catchments, particularly for periods with increasing temperature, where snow cover, glaciers and frozen soils are widely distributed. Concentration/flux-discharge in discharge was dominated by a well-defined power law relation, with R2 values lower on rising than falling limbs. This finding has important implications for efforts to estimate annual concentrations and export of major solutes from similar catchments in cold regions where only river discharge is available. Concentrations of conservative solutes in discharge resulted from mixing of two end-members at the most upper gauging sections (YSP, TTH and HHY), and three end-members at the lower gauging sections (ZMD, JM, JG and TNH), with relatively constant solute concentrations in end-members. Relationship between the fractional contributions of meltwater and/or precipitation and groundwater and river discharge followed the same relation

Asian Carp Survivability Experiments and Water Transport Surveys in the Illinois River, Volume 1

DTIC Science & Technology

2013-01-01

developmental stages of the eggs and larvae of the four species of Asian carp in the Yangtze River. These stages begin with egg fertilization and end with the...hatching in the Yangtze River after about 38 hours. Development to the juvenile stage in silver and bighead carp was estimated to take about 60-70 days...Native to the Yangtze River, China. U.S. Geological Survey Data Series 239, 51 pp. Coulter, A. & Goforth, R. R. 2011. Silver and Bighead Carp

Research Note:Effects of human activities on the Yangtze River suspended sediment flux into the estuary in the last century

NASA Astrophysics Data System (ADS)

Yang, S. L.; Shi, Z.; Zhao, H. Y.; Li, P.; Dai, S. B.; Gao, A.

The surface erosion area in the Yangtze River basin increased from 364×103 km2 in the 1950s to 707×103 km2 in 2001 due to a great increase in population. Based on the regression relationship between surface erosion area and population, the surface erosion area was predicted to be about 280×103 km2 at the beginning of the 20th century. The sediment yield, which increased by about 30% during the first six decades of the 20th century, was closely related to the surface erosion area in this river basin. The Yangtze annual suspended sediment flux into the estuary was about 395×106 t a-1 at the beginning of the century, and this gradually increased to an average of 509×106 t a-1 in the 1960s. The increase in the suspended sediment flux into the estuary was accelerated in the 1950s and the 1960s due to the rapid increase in population and land use immediately after the Second World War and the Liberation War. After the riverine suspended sediment flux reached its maximum in the 1960s, it decreased to <206×106 t a-1 in 2003. Construction of dams was found to be the principal cause for this decreasing trend because, during the same period, (a) the riverine water discharge did not show a decreasing trend, (b) water diversion was not influential and (c) sedimentation in lakes and canals of the middle and lower reaches did not increase. The total storage capacity of reservoirs has increased dramatically over the past half century. The amount of sediment trapped in reservoirs has increased to more than half a billion t a-1. As a result, the suspended sediment flux into the estuary dramatically decreased, even though the sediment yield from many areas of the basin increased in recent decades. Human activities gradually increased the suspended sediment flux into the estuary before the 1960s and then rapidly decreased it. The last century was a period when the Yangtze suspended sediment flux into the estuary was dramatically affected by human activities.

Historical trajectories and restoration strategies for the Mississippi River alluvial valley

Treesearch

Brice B. Hanberry; John M. Kabrick; Hong S. He; Brian J. Palik

2012-01-01

Unlike upland forests in the eastern United States, little research is available about the composition and structure of bottomland forests before Euro-American settlement. To provide a historical reference encompassing spatial variation for the Lower Mississippi River Alluvial Valley, we quantified forest types, species distributions, densities, and stocking of...

An intimate understanding of place: Charles Sauriol and Toronto’s Don River Valley, 1927-1989.

PubMed

Bonnell, Jennifer

2011-01-01

Every summer from 1927 to 1968, Toronto conservationist Charles Sauriol and his family moved from their city home to a rustic cottage just a few kilometres away, within the urban wilderness of Toronto’s Don River Valley. In his years as a cottager, Sauriol saw the valley change from a picturesque setting of rural farms and woodlands to an increasingly threatened corridor of urban green space. His intimate familiarity with the valley led to a lifelong quest to protect it. This paper explores the history of conservation in the Don River Valley through Sauriol’s experiences. Changes in the approaches to protecting urban nature, I argue, are reflected in Sauriol’s personal experience – the strategies he employed, the language he used, and the losses he suffered as a result of urban planning policies. Over the course of Sauriol’s career as a conservationist, from the 1940s to the 1990s, the river increasingly became a symbol of urban health – specifically, the health of the relationship between urban residents and the natural environment upon which they depend. Drawing from a rich range of sources, including diary entries, published memoirs, and unpublished manuscripts and correspondence, this paper reflects upon the ways that biography can inform histories of place and better our understanding of individual responses to changing landscapes.

Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes

PubMed Central

Yang, S. L.; Xu, K. H.; Milliman, J. D.; Yang, H. F.; Wu, C. S.

2015-01-01

The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003–2012) was 67 km3/yr (7%) lower than that of the previous 50 years (1950–2002), and 126 km3/yr less compared to the relatively wet period of pre-TGD decade (1993–2002). Most (60–70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950–1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors. PMID:26206169

Infilling and flooding of the Mekong River incised valley during deglacial sea-level rise

NASA Astrophysics Data System (ADS)

Tjallingii, Rik; Stattegger, Karl; Wetzel, Andreas; Van Phach, Phung

2010-06-01

The abrupt transition from fluvial to marine deposition of incised-valley-fill sediments retrieved from the southeast Vietnamese shelf, accurately records the postglacial transgression after 14 ka before present (BP). Valley-filling sediments consist of fluvial mud, whereas sedimentation after the transgression is characterized by shallow-marine carbonate sands. This change in sediment composition is accurately marked in high-resolution X-ray fluorescence (XRF) core scanning records. Rapid aggradation of fluvial sediments at the river mouth nearly completely filled the Mekong incised valley prior to flooding. However, accumulation rates strongly reduced in the valley after the river-mouth system flooded and stepped back. This also affected the sediment supply to deeper parts of the southeast Vietnamese shelf. Comparison of the Mekong valley-filling with the East Asian sea-level history of sub- and inter-tidal sediment records shows that the transgressive surface preserved in the incised-valley-fill records is a robust sea-level indicator. The valley was nearly completely filled with fluvial sediments between 13.0 and 9.5 ka BP when sea-level rose rather constantly with approximately 10 mm/yr, as indicated by the East Asian sea-level record. At shallower parts of the shelf, significant sediment reworking and the establishment of estuarine conditions at the final stage of infilling complicates accurate dating of the transgressive surface. Nevertheless, incised-valley-fill records and land-based drill sites indicate a vast and rapid flooding of the shelf from the location of the modern Vietnamese coastline to the Cambodian lowlands between 9.5 ka and 8.5 ka BP. Fast flooding of this part of the shelf is related with the low shelf gradient and a strong acceleration of the East Asian sea-level rise from 34 to 9 meter below modern sea level (mbsl) corresponding to the sea-level jump of melt water pulse (MWP) 1C.

Sublacustrine river valley in the shelf zone of the Black Sea parallel to the Bulgarian coast

NASA Astrophysics Data System (ADS)

Preisinger, A.; Aslanian, S.; Beigelbeck, R.; Heinitz, W.-D.

2009-04-01

The considered sublacustrine river valley is situated in the shelf zone of the Black Sea. It runs in parallel to the Bulgarian coast, was formed in the time period of the Younger Dryas (Preisinger et al., 2005), and features an inclination of about 0.5 m/km. An about 200 km long sediment wall separates the approximately 10 km broad river valley from the outside shelf zone. This wall was generated during the Older Dryas until the beginning of the Younger Dryas. Its shape was formed by transportation of water and sediment from the Strait of Kerch by a circulating rim current in the Black Sea and water as well as sediment flow of the Danube in direction to the Bosporus. New investigations of the sediments of this river valley were performed by utilizing a Sediment Echo Sounder (SES 2000). This Echo Sounder is a parametric sub-bottom profiler enabling a high resolution sub-bottom analyses. It is capable of penetrating sea beds up to more than 50 m of water depth. The received echo data are real-time processed. The signal amplitudes are valuated in context to a logarithmic scale and graphically visualized by means of a colorized echogram utilizing false colours ranging from red for a high to blue representing a low signal (W.-D. Heinitz et al., 1998). The highest signal (red) is given by the acoustic impedance of the boundary between sea water and river sediment. The echograms of the river valley depict spatially isolated (red) high-signal peaks, which are periodically repeated in vertical direction between the sediment surface and the bottom of the valley. The number of these high-signal parts increase with an increasing valley depth. Studying of the distribution of these peaks allows to draw conclusions regarding the content and composition of the sediment. This prediction of the sediment composition obtained by means of the SES 2000 was successfully verified by analyzing a gravity core taken near Nos Maslen (at 44 m water depth) with a particular focus on the water

Quaternary Sedimentary and Geomorphic History of River Valleys in the Lake Titicaca Basin, Peru and Bolivia

NASA Astrophysics Data System (ADS)

Rigsby, C. A.; Farabaugh, R. L.; Baker, P. A.

2002-12-01

Lacustrine sediments have become important archives of paleoclimatic history in the tropical Andes of South America. The history of lake level of Lake Titicaca (LT) has played a central role in these reconstructions. Here we report on our ongoing studies of the late Quaternary sedimentary and geomorphic histories of two of the major tributaries to LT (the Rios Ramis and Ilave) and on our earlier studies of LT's only outlet (the Rio Desaguadero). The strata and fluvial terraces in these valleys record large-scale aggradation and downcutting events that are apparently correlative with both climate changes in the LT basin and local complex response mechanisms (changes in sediment source, topographic variability, etc.). Both the Ramis and Ilave valleys have 5 terrace tracts, ranging from less than 1 m to approximately 53 m above the river level and occurring as both paired and unpaired tracts and as cut-fill, fill-, and strath terraces. The Rio Desaguadero valley has 4, locally paired, cut-fill and fill terrace tracts that range in height from approximately 2 m to 40 m above river level. In all three valleys, the terraces are underlain by meandering- and braided-river sands and gravels and by lacustrine muds. Radiocarbon dates from the Ilave and Desaguadero valleys suggest that strata in these valleys aggraded during periods of high or rising levels of LT, high or increasing sedimentation rates in the Rio Ilave delta, high (but variable) regional precipitation, and lacustrine sedimentation in the upstream-most reaches of the Rio Desaguadero valley. These same strata were downcut during periods of low or falling levels of LT, low or rapidly decreasing sedimentation rates in the Rio Ilave delta, and lower regional precipitation and runoff. In all three valleys, aggradational periods are punctuated by equilibrium periods of soil formation, downcutting events are episodic, and the most recent events are aggradation and subsequent downcutting of a low, young fill

Prediction of hydrological responds to climate changes in the Upper Yangtze River Basin, China

NASA Astrophysics Data System (ADS)

Yang, X.; Ren, L.; Wang, Y.; Zhang, M.; Liu, Y.; Jiang, S.; Yuan, F.

2017-12-01

Climate changes have direct effects on hydrological cycle, with the increasing temperature and seasonal shift of precipitation. Therefore, understanding of how climate change may affect the population and water resources and economic development is critical to the water and food security for China. This study aims to evaluate the potential impacts of future climate changes on water resources of the upper basin of Yangtze River (the area controlled by the Yichang hydrological station) using the variable infiltration capacity (VIC) model driven by composite observations (1961-2005) and projections of eight CMIP5 models under scenarios RCP4.5 and RCP8.5 from 2006 to 2099. The raw eight CMIP5 models have been downscaled by the equidistant cumulative distribution functions (EDCDF) statistical downscaling approach from 1961 to 2099. The assessment of the performance of model simulated precipitation and temperature were calculated by comparing to the observations during the historical period (1961-2005). For the same variables, eight CMIP5 models for RCP 4.5 and RCP 8.5 downscaled by EDCDF method were generated during the future period (2006-2099). Overall, the VIC model performed well in monthly streamflow simulation, with the Nash-Sutcliffe coefficient of efficiency (NSCE) 0.92 and 0.97 for calibration and validation, respectively. The annual precipitation is projected to increase by 6.3mm and 8.6mm per decade and the annual temperature will increase by 0.22 °C and 0.53°C per decade (2006-2099) for RCP4.5 and RCP8.5, respectively. In the future period, The total runoff of the study basins would either remain stable or moderately increase by 2.7% and 22.4% per decade, the evapotranspiration increase by 2mm and 13mm per decade, and the soil moisture will reduce by -0.1% and -7.4% per decade under RCP4.5 and RCP8.5, respectively. The changes of model-simulated soil moisture, runoff, and evapotranspiration suggest that there probably be an increasing risk of drought in

Characterization of geomorphic units in the alluvial valleys and channels of Gulf Coastal Plain rivers in Texas, with examples from the Brazos, Sabine, and Trinity Rivers, 2010

USGS Publications Warehouse

Coffman, David K.; Malstaff, Greg; Heitmuller, Franklin T.

2011-01-01

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, described and characterized examples of geomorphic units within the channels and alluvial valleys of Texas Gulf Coastal Plain rivers using a geomorphic unit classification scale that differentiates geomorphic units on the basis of their location either outside or inside the river channel. The geomorphic properties of a river system determine the distribution and type of potential habitat both within and adjacent to the channel. This report characterizes the geomorphic units contained in the river channels and alluvial valleys of Texas Gulf Coastal Plain rivers in the context of the River Styles framework. This report is intended to help Texas Instream Flow Program practitioners, river managers, ecologists and biologists, and others interested in the geomorphology and the physical processes of the rivers of the Texas Gulf Coastal Plain (1) gain insights into how geomorphic units develop and adjust spatially and temporally, and (2) be able to recognize common geomorphic units from the examples cataloged in this report. Recent aerial imagery (high-resolution digital orthoimagery) collected in 2008 and 2009 were inspected by using geographic information system software to identify representative examples of the types of geomorphic units that occurred in the study area. Geomorphic units outside the channels of Texas Gulf Coastal Plain rivers are called \\"valley geomorphic units\\" in this report. Valley geomorphic units for the Texas Gulf Coastal Plain rivers described in this report are terraces, flood plains, crevasses and crevasse splays, flood-plain depressions, tie channels, tributaries, paleochannels, anabranches, distributaries, natural levees, neck cutoffs, oxbow lakes, and constructed channels. Channel geomorphic units occur in the river channel and are subject to frequent stresses associated with flowing water and sediment transport; they adjust (change) relatively quickly in

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters.

PubMed

Lv, Xuemin; Lu, Yi; Yang, Xiaoming; Dong, Xiaorong; Ma, Kunpeng; Xiao, Sanhua; Wang, Yazhou; Tang, Fei

2015-03-31

A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water.

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters

PubMed Central

Lv, Xuemin; Lu, Yi; Yang, Xiaoming; Dong, Xiaorong; Ma, Kunpeng; Xiao, Sanhua; Wang, Yazhou; Tang, Fei

2015-01-01

A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water. PMID:25825837

Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors.

PubMed

Zhang, Hui; Xian, Weiwei; Liu, Shude

2016-01-01

This study investigated the response of the ichthyoplankton community to environmental changes in the Yangtze Estuary using canonical correspondence analysis. Ichthyoplankton community and environmental data were recorded during the autumns of 1998, 2000, 2002, 2003, 2004, 2007 and 2009. Among the ichthyoplankton, the dominant larval and juvenile families were the Engraulidae, Gobiidae and Salangidae, and the most common eggs were from Trichiurus lepturus. The ichthyoplankton was identified via canonical correspondence analysis to three assemblages: an estuary assemblage dominated by Chaeturichthys stigmatias, a coastal assemblage dominated by Engraulis japonicus and Stolephorus commersonii, and an offshore assemblage dominated by Trichiurus lepturus. Regarding environmental factors in the Yangtze Estuary, suspended matter and surface seawater salinity were the main factors influencing the distributions of the different assemblages, while sediment from the Yangtze River during the rainy season and chlorophyll a were the principle drivers of the annual variances in the distribution of ichthyoplankton assemblages. Our aims in this study were to provide detailed characterizations of the ichthyoplankton assemblage in the autumns of seven years, examine the long-term dynamics of autumn ichthyoplankton assemblages, and evaluate the influence of environmental factors on the spatial distribution and inter-annual variations of ichthyoplankton assemblages associated with the Yangtze Estuary.

Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors

PubMed Central

Liu, Shude

2016-01-01

This study investigated the response of the ichthyoplankton community to environmental changes in the Yangtze Estuary using canonical correspondence analysis. Ichthyoplankton community and environmental data were recorded during the autumns of 1998, 2000, 2002, 2003, 2004, 2007 and 2009. Among the ichthyoplankton, the dominant larval and juvenile families were the Engraulidae, Gobiidae and Salangidae, and the most common eggs were from Trichiurus lepturus. The ichthyoplankton was identified via canonical correspondence analysis to three assemblages: an estuary assemblage dominated by Chaeturichthys stigmatias, a coastal assemblage dominated by Engraulis japonicus and Stolephorus commersonii, and an offshore assemblage dominated by Trichiurus lepturus. Regarding environmental factors in the Yangtze Estuary, suspended matter and surface seawater salinity were the main factors influencing the distributions of the different assemblages, while sediment from the Yangtze River during the rainy season and chlorophyll a were the principle drivers of the annual variances in the distribution of ichthyoplankton assemblages. Our aims in this study were to provide detailed characterizations of the ichthyoplankton assemblage in the autumns of seven years, examine the long-term dynamics of autumn ichthyoplankton assemblages, and evaluate the influence of environmental factors on the spatial distribution and inter-annual variations of ichthyoplankton assemblages associated with the Yangtze Estuary. PMID:27114877

40Ar/39Ar mica dating of late Cenozoic sediments in the upper Yangtze: Implications for sediment provenance and drainage evolution

NASA Astrophysics Data System (ADS)

Sun, Xilin; Li, Chang'an; Kuiper, Kuiper; Zhang, Zengjie; Wijbrans, Jan

2017-04-01

The development of the river systems in East Asia is closely linked to the uplift of the Tibetan plateau caused by collision of the India-Eurasia. The Yangtze River is the largest river in Asia and the timing and exact causes of its formation are still a matter of debate. Controversy exists for example on the start of the connection of the eastern Tibetan rivers to the eastward flowing Yangtze instead of the southward flowing Red River. Here we use the 40Ar/39Ar dating of detrital micas (muscovite and biotite) and muscovite geochemistry to constrain the sediment provenance in the eastern Tibetan Plateau. The remarkable spatial and temporal variation in sediment provenance allow us to extract information about the evolution of the upper Yangtze River. The combined data suggest that the upper Jinsha River upstream from Shigu town lost its connection with the southward flowing Red River at least earlier than the Pliocene. To the east of Shigu, the Yalong and Jinsha rivers flowed across the Yuanmou Basin into the Red River before 3.1 Ma, but abandoned this connection and turned east somewhere between 3.1 and 2.1 Ma. Our results rule out the possibility of a west-flowing Jinsha River since 1.58 Ma. The current stream directions between Shigu and Panzhihua go north, south and east and must have been formed at that time. Our data also shed new light on the evolution of the Dadu River. The Dadu River did not flow southward into Yuanmou Basin at least since 4.8 Ma but flowed into the Jinsha River along the Anninghe Fault. These capture events are closely linked to the tectonism of the eastern Tibetan Plateau and intensification of the East Asia monsoon.

Comparative study of carbonic anhydrase activity in waters among different geological eco-environments of Yangtze River basin and its ecological significance.

PubMed

Nzung'a, Sila Onesmus; Pan, Weizhi; Shen, Taiming; Li, Wei; Qin, Xiaoqun; Wang, Chenwei; Zhang, Liankai; Yu, Longjiang

2018-04-01

This study provides the presence of carbonic anhydrase (CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO 3 - concentration and CO 2 sink flux. Different degrees of CA activity could be detected in almost all of the water samples from different geological eco-environments in all four seasons. The CA activity of water samples from karst areas was significantly higher than from non-karst areas (PP3 - concentration (r=0.672, P2 sink flux (r=0.602, P=0.076) in karst areas. This suggests that CA in waters might have a promoting effect on carbon sinks for atmospheric CO 2 in karst river basins. In conditions of similar geological type, higher CA activity was generally detected in water samples taken from areas that exhibited better eco-environments, implying that the CA activity index of waters could be used as an indicator for monitoring ecological environments and protection of river basins. These findings suggest that the role of CA in waters in the karst carbon sink potential of river basins is worthy of further in-depth studies. Copyright © 2017. Published by Elsevier B.V.

Quaternary Geochronology, Paleontology, and Archaeology of the Upper San Pedro River Valley, Sonora, Mexico

NASA Astrophysics Data System (ADS)

Gaines, E. P.

2013-12-01

This poster presents the results of multi-disciplinary investigations of the preservation and extent of Quaternary fossil-bearing strata in the San Pedro River Valley in Sonora, Mexico. Geologic deposits in the portions of the San Pedro Valley in southern Arizona contain one of the best late Cenozoic fossil records known in North America and the best record of early humans and extinct mammals on the continent. The basin in the U.S. is one of the type locations for the Blancan Land Mammal Age. Hemiphilian and Irvingtonian fossils are common. Rancholabrean remains are widespread. Strata in the valley adjacent to the international border with Mexico have yielded the densest concentration of archaeological mammoth-kill sites known in the western hemisphere. Despite more than 60 years of research in the U.S., however, and the fact that over one third of the San Pedro River lies south of the international boundary, little has been known about the late Cenozoic geology of the valley in Mexico. The study reported here utilized extensive field survey, archaeological documentation, paleontological excavations, stratigraphic mapping and alluvial geochronology to determine the nature and extent of Quaternary fossil-bearing deposits in the portions of the San Pedro Valley in Sonora, Mexico. The results demonstrate that the Plio-Pleistocene fossil -bearing formations known from the valley in Arizona extend into the uppermost reaches of the valley in Mexico. Several new fossil sites were discovered that yielded the remains of Camelids, Equus, Mammuthus, and other Proboscidean species. Late Pleistocene archaeological remains were found on the surface of the surrounding uplands. AMS radiocarbon dating demonstrates the widespread preservation of middle- to late- Holocene deposits. However, the late Pleistocene deposits that contain the archaeological mammoth-kill sites in Arizona are absent in the valley in Mexico, and are now known to be restricted to relatively small portions of

Source identification, geochemical normalization and influence factors of heavy metals in Yangtze River Estuary sediment.

PubMed

Sun, Xueshi; Fan, Dejiang; Liu, Ming; Tian, Yuan; Pang, Yue; Liao, Huijie

2018-06-18

Sediment samples, including 40 surface samples and 12 sediment cores, were collected from 52 stations of the Yangtze River Estuary (YRE) in 2015 and 2016. The 95% linear prediction intervals (LPI) and principal components analysis (PCA), were conducted to evaluate the metal sources and grain-size effect (GSE). The in situ physico-chemical properties of pH, Eh, DO, salinity, temperature and turbidity were combined to elucidate the relationships between environmental factors and the fate of heavy metals in the river-estuary-shelf system. This study indicates a decreasing trend of metals in sediments from the estuary towards the adjacent shelf and the river channel and that Zn, Cu and Cr are mainly derived from natural processes throughout the catchment, whereas Pb appears to have anthropogenic inputs via atmospheric deposition. Furthermore, considering the best fit regression lines between the concentrations of Al and heavy metals as well as the deficiencies of the conventional C elements /C Al method, we introduce an approach (Al-SN: Al-scope normalization) that can eliminate the GSE on heavy metals and be applied to other estuaries. After Al-scope normalization, the relatively constant levels of Zn, Cu and Cr that remain in sediments from the river channel to the estuary and shelf confirmed that the variation of grain size in sediments almost entirely explained the distribution patterns of sediment toxicity in the YRE, while the enrichment of Pb in estuarine sediments could be attributed to its chemical species and physico-chemical properties. The results further suggest that the relationship between grain size and spatial behavior of sediment pollutants should be given priority over the contamination assessment and provenance discrimination in estuarine or similar environments with complex sediment compositions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Morphology and mechanism of the very large dunes in the tidal reach of the Yangtze River, China

NASA Astrophysics Data System (ADS)

Shuwei, Zheng; Heqin, Cheng; Shuaihu, Wu; Shengyu, Shi; Wei, Xu; Quanping, Zhou; Yuehua, Jiang

2017-05-01

High-resolution multibeam data was used to interpret the surface morphology of very large dunes (VLDs) in the tidal reach of the Yangtze River, China. These VLDs can be divided into three categories according to their surface morphological characteristics. (1) VLDs-I: those with a smooth surface and cross-section; (2) VLDs-II: those accompanied by secondary dunes; (3) VLDs-III: those accompanied by secondary dunes and numerous elliptical pits. Parameters and spatial distribution of VLDs, and bed surface sediment were analyzed in the laboratory. Overall, channel morphology is an important factor affecting the development of VLDs, and channels with narrow and straight and certain water surface slope are facilitating the development of VLDs by constraining stream power. Meanwhile, distribution density of VLDs depicts a decreasing trend from Chizhou towards the estuary, are probably influenced by channel morphology and width. Associated pits in VLDs-III change the 3D dune morphology by distributing in secondary dunes as beads. The Three Gorges Dam project (TGP) leads to the bed surface sediment activity frequently and leads to the riverbed surface sediment coarsens, which promotes the further development of dunes. Moreover, other human activities, such as river regulation project, sand mining and Deep Water Channel Regulation Project have changed the regional river boundary conditions and hydrodynamic conditions are influential on the development of VLDs.

SRTM Perspective View with Landsat Overlay: Santa Paula, and Santa Clara River Valley, California

NASA Image and Video Library

2000-12-14

Rectangular fields of the agriculturally rich Santa Clara River Valley are visible in this perspective view generated by using data from the Shuttle Radar Topography Mission and an enhanced Landsat image.

Particulate Matter and Gaseous Pollutions in Three Metropolises along the Chinese Yangtze River: Situation and Implications.

PubMed

Mao, Mao; Zhang, Xiaolin; Yin, Yan

2018-05-28

The situation of criteria atmospheric pollutants, including particulate matter and trace gases (SO₂, NO₂, CO and O₃), over three metropolises (Chongqing, Wuhan, and Nanjing), representing the upstream, midstream and downstream portions of the Yangtze River Basin from September 2015 to August 2016 were analyzed. The maximum annual mean PM 2.5 and PM 10 concentrations were 61.3 and 102.7 μg/m³ in Wuhan, while highest annual average gaseous pollutions occurred in Nanjing, with 49.6 and 22.9 ppb for 8 h O₃ and NO₂, respectively. Compared to a few years ago, SO₂ and CO mass concentrations have dropped to well below the qualification standards, and the O₃ and NO₂ concentrations basically meet the requirements though occasionally is still high. In contrary, about 13%, 25%, 22% for PM 2.5 , and 4%, 17%, 15% for PM 10 exceed the Chinese Ambient Air Quality Standard (CAAQS) Grade II. Particulate matter, especially PM 2.5 , is the most frequent major pollutant to poor air quality with 73%, 64% and 88% accounting for substandard days. Mean PM 2.5 concentrations on PM 2.5 episode days are 2⁻3 times greater than non-episode days. On the basis of calculation of PM 2.5 /PM 10 and PM 2.5 /CO ratios, the enhanced particulate matter pollution on episode days is closely related to secondary aerosol production. Except for O₃, the remaining five pollutants exhibit analogous seasonal patterns, with the highest magnitude in winter and lowest in summer. The results of back trajectories show that air pollution displays synergistic effects on local emissions and long range transport. O₃ commonly demonstrated negative correlations with other pollutants, especially during winter, while moderate to strong positive correlation between particulate matter and NO₂, SO₂, CO were seen. Compared to pollutant substandard ratios over three megacities in eastern China (Beijing, Shanghai, and Guangzhou), the situation in our studied second-tier cities are also severe. The

Timing and origin for sand dunes in the Green River Lowland of Illinois, upper Mississippi River Valley, USA

USGS Publications Warehouse

Miao, X.; Hanson, P.R.; Wang, Hongfang; Young, A.R.

2010-01-01

The recent increase in dune studies in North America has been heavily focused in the Great Plains, while less attention has historically been given to the dune fields east of the Mississippi River. Here we report ages and suggest a potential sediment source for sand dunes in the Green River Lowland, Illinois, which may provide a better understanding of the dynamic interactions between eolian, glacial, lacustrine and fluvial processes that shaped the landscapes of the upper Midwest. Seven coherent optically stimulated luminescence ages (OSL, or optical ages) obtained from four sites suggest that major dune construction in the Green River Lowland occurred within a narrow time window around 17,500 ago. This implies either an enhanced aridity or an episodic increase of sediment supply at 17,500 years ago, or combination of the both. Contrary to previous assertions that dune sand was sourced from the deflation of the underlying outwash sand deposited when the Lake Michigan Lobe retreated from the area, we propose that Green River Lowland dunes sand originated from the Green Bay Lobe through the Rock River. Specifically, sediment supply increased in the Rock River valley during drainage of Glacial Lake Scuppernong, which formed between ???18,000 and 17,000 years ago, when the Green Bay Lobe retreated from its terminal moraine. The lake drained catastrophically through the Rock River valley, providing glacial sediment and water to erode the preexisting sandy sediments. Throughout the remainder of the late Pleistocene, the Laurentide Ice Sheet drained into larger more northerly glacial lakes that in turn drained through other river valleys. Therefore, the dunes in the Green River Lowland formed only during the catastrophic drainage of Glacial Lake Scuppernong, but were stabilized through the remainder of the Pleistocene. This scenario explains the abrupt dune construction around 17,500 years ago, and explains the lack of later dune activity up to the Pleistocene

Relationship between Dongting Lake and surrounding rivers under the operation of the Three Gorges Reservoir, China.

PubMed

Zhan, Lucheng; Chen, Jiansheng; Zhang, Shiyin; Huang, Dewen; Li, Ling

2015-01-01

The natural flow properties of the Yangtze River have been changed completely following the construction of the Three Gorges Dam. The dam's operation has affected the resources and environment in the middle and lower reaches of the Yangtze River, changing the hydrological conditions and ecological environment of the Dongting Lake. During three different dispatching periods of the reservoir, we took triplicate samples of the river and lake water. All the samples were analysed for δ(2)H and δ(18)O to determine the relationship between the lake and the Yangtze River (and other rivers), and to evaluate objectively the influence of the dam's operation on the lake. During the period of water-supply dispatch, the Four Rivers and Miluo River are the main recharge sources of the lake. During the flood-storage dispatching period, the Dongting Lake is recharged largely by the Three Outlets and the Four Rivers, whereas during the period of water-storage dispatch, most of the lake's water originates from the Miluo, Xiang, Zi, and Yuan rivers. Although the Yangtze River only contributes significantly to the lake's recharge through the Three Outlets during the flood-storage dispatching period, the lake discharges large amounts of water into the Yangtze River during all three periods. Through the operation of the reservoir, it should be ensured that the water level of the Dongting Lake is not too low during the dry season, nor too high during the wet season, thus preventing the lake region from future flood and drought disasters.

Fuel regulation in inland navigation: reduced soil black carbon and PAH deposition in river valleys

NASA Astrophysics Data System (ADS)

Bläsing, M.; Schwark, L.; Amelung, W.; Lehndorff, E.

2016-12-01

Inland navigation (IN) is of increasing importance in the transport sector. Most inland waterways and inland ports are located in/near urban regions; hence many people are exposed to emissions from IN. However, its contribution to environmental quality is not yet known. Accordingly, we aimed at identifying IN emissions in the environment, and investigating consequences of the S-reduction in ship diesel (EU regulation 2009/30/EC) on IN emissions. To do so, topsoil samples were taken from vineyards in valley transects (perpendicular to rivers) at two German inland waterways (Rhine, Moselle) and one ship-free reference valley (Ahr) and analyzed for polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC). To elucidate the effect of fuel regulation (effective since 2011), samplings were performed from 2010 to 2013. Additionally, the potential dispersal of IN emissions was simulated by a Lagrangian stochastic model. Before regulating the S-content of ship diesel by the EU directive soil samples indicated a clear impact of IN emissions on BC and PAH deposits, in at least 200 and 350 m distance to the Moselle and Rhine river, respectively. IN emissions accounted for approximately 30% of total soil BC. However, soils along waterways comprised only slightly more BC than soils in the ship-free Ahr Valley, with BC contents comparable to rural to suburban European soils. Contents of PAHs in river valleys compared to remote to urban pollution load. In the course of the fuel regulation, BC and PAH deposits in soil were reduced within three years by 30-60%, respectively. Also the quality of emissions changed to higher shares of low molecular weight PAHs and smaller proportions of soot-BC, indicating less deposition of IN emissions. The impact of the fuel regulation was more obvious at the Rhine Valley than at the Moselle Valley, likely because of higher ship traffic volume at the former. Overall, fuel regulation was effective in reducing IN emissions along inland waterways.

Occurrence and ecological risk assessment of organic micropollutants in the lower reaches of the Yangtze River, China: A case study of water diversion.

PubMed

Yan, Zhenhua; Yang, Haohan; Dong, Huike; Ma, Binni; Sun, Hongwei; Pan, Ting; Jiang, Runren; Zhou, Ranran; Shen, Jie; Liu, Jianchao; Lu, Guanghua

2018-08-01

Water diversion has been increasingly applied to improve water quality in many water bodies. However, little is known regarding pollution by organic micropollutants (OMPs) in water diversion projects, especially at the supplier, and this pollution may threaten the quality of transferred water. In the present study, a total of 110 OMPs belonging to seven classes were investigated in water and sediment collected from a supplier of the Yangtze River within four water diversion projects. A total of 69 and 58 target OMPs were detected in water and sediment, respectively, at total concentrations reaching 1041.78 ng/L and 5942.24 ng/g dry weight (dw). Polycyclic aromatic hydrocarbons (PAHs) and pharmaceuticals were the predominant pollutants identified. When preliminarily compared with the pollution in the receiving water, the Yangtze River generally exhibited mild OMPs pollution and good water quality parameters, implying a clean water source in the water diversion project. However, in Zongyang and Fenghuangjing, PAHs pollution was more abundant than that in the corresponding receiving water in Chaohu Lake. Ammonia nitrogen pollution in the Wangyu River was comparable to that in Taihu Lake. These findings imply that water diversion may threaten receiving waters in some cases. In addition, the risks of all detected pollutants in both water and sediment were assessed. PAHs in water, especially phenanthrene and high-molecular-weight PAHs, posed high risks to invertebrates, followed by the risks to fish and algae. Pharmaceuticals, such as antibiotics and antidepressants, may also pose risks to algae and fish at a number of locations. To the best of our knowledge, this report is the first to describe OMPs pollution in water diversion projects, and the results provide a new perspective regarding the security of water diversion projects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Applying a water quality index model to assess the water quality of the major rivers in the Kathmandu Valley, Nepal.

PubMed

Regmi, Ram Krishna; Mishra, Binaya Kumar; Masago, Yoshifumi; Luo, Pingping; Toyozumi-Kojima, Asako; Jalilov, Shokhrukh-Mirzo

2017-08-01

Human activities during recent decades have led to increased degradation of the river water environment in South Asia. This degradation has led to concerns for the populations of the major cities of Nepal, including those of the Kathmandu Valley. The deterioration of the rivers in the valley is directly linked to the prevalence of poor sanitary conditions, as well as the presence of industries that discharge their effluents into the river. This study aims to investigate the water quality aspect for the aquatic ecosystems and recreation of the major rivers in the Kathmandu Valley using the Canadian Council of Ministers of the Environment water quality index (CCME WQI). Ten physicochemical parameters were used to determine the CCME WQI at 20 different sampling locations. Analysis of the data indicated that the water quality in rural areas ranges from excellent to good, whereas in denser settlements and core urban areas, the water quality is poor. The study results are expected to provide policy-makers with valuable information related to the use of river water by local people in the study area.

Geochemical processes in the Onyx River, Wright Valley, Antarctica: Major ions, nutrients, trace metals

NASA Astrophysics Data System (ADS)

Green, William J.; Stage, Brian R.; Preston, Adam; Wagers, Shannon; Shacat, Joseph; Newell, Silvia

2005-02-01

We present data on major ions, nutrients and trace metals in an Antarctic stream. The Onyx River is located in Wright Valley (77-32 S; 161-34 E), one of a group of ancient river and glacier-carved landforms that comprise the McMurdo Dry Valleys of Antarctica. The river is more than 30 km long and is the largest of the glacial meltwater streams that characterize this relatively ice-free region near the Ross Sea. The complete absence of rainfall in the region and the usually small contributions of glacially derived tributaries to the main channel make this a comparatively simple system for geochemical investigation. Moreover, the lack of human impacts, past or present, provides an increasingly rare window onto a pristine aquatic system. For all major ions and silica, we observe increasing concentrations with distance from Lake Brownworth down to the recording weir near Lake Vanda. Chemical weathering rates are unexpectedly high and may be related to the rapid dissolution of ancient carbonate deposits and to the severe physical weathering associated with the harsh Antarctic winter. Of the nutrients, nitrate and dissolved reactive phosphate appear to have quite different sources. Nitrate is enriched in waters near the Lower Wright Glacier and may ultimately be derived from stratospheric sources; while phosphate is likely to be the product of chemical weathering of valley rocks and soils. We confirm the work of earlier investigations regarding the importance of the Boulder Pavement as a nutrient sink. Dissolved Mn, Fe, Ni, Cu, and Cd are present at nanomolar levels and, in all cases, the concentrations of these metals are lower than in average world river water. We hypothesize that metal uptake and exchange with particulate phases along the course of the river may serve as a buffer for the dissolved load. Concurrent study of these three solute classes points out significant differences in the mechanisms and sites of their removal from the Onyx River.

The Ohio River Valley CO2 Storage Project AEP Mountaineer Plan, West Virginia

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

Neeraj Gupta

2009-01-07

This report includes an evaluation of deep rock formations with the objective of providing practical maps, data, and some of the issues considered for carbon dioxide (CO{sub 2}) storage projects in the Ohio River Valley. Injection and storage of CO{sub 2} into deep rock formations represents a feasible option for reducing greenhouse gas emissions from coal-burning power plants concentrated along the Ohio River Valley area. This study is sponsored by the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL), American Electric Power (AEP), BP, Ohio Coal Development Office, Schlumberger, and Battelle along with its Pacific Northwest Division. Anmore » extensive program of drilling, sampling, and testing of a deep well combined with a seismic survey was used to characterize the local and regional geologic features at AEP's 1300-megawatt (MW) Mountaineer Power Plant. Site characterization information has been used as part of a systematic design feasibility assessment for a first-of-a-kind integrated capture and storage facility at an existing coal-fired power plant in the Ohio River Valley region--an area with a large concentration of power plants and other emission sources. Subsurface characterization data have been used for reservoir simulations and to support the review of the issues relating to injection, monitoring, strategy, risk assessment, and regulatory permitting. The high-sulfur coal samples from the region have been tested in a capture test facility to evaluate and optimize basic design for a small-scale capture system and eventually to prepare a detailed design for a capture, local transport, and injection facility. The Ohio River Valley CO{sub 2} Storage Project was conducted in phases with the ultimate objectives of demonstrating both the technical aspects of CO{sub 2} storage and the testing, logistical, regulatory, and outreach issues related to conducting such a project at a large point source under realistic constraints. The

Geologic evolution of the lower Connecticut River valley: Influence of bedrock geology, glacial deposits, and sea level

USGS Publications Warehouse

Stone, Janet R.; Lewis, Ralph S.

2016-01-01

This fieldtrip illustrates the character of the lower Connecticut River bedrock valley, in particular its depth, and the lithology and structure of bedrock units it crosses. It examines the character and distribution of the glaciodeltaic terraces that partially fill the valley and discusses the depth of postglacial incision into them.

Process-based, forecast modeling of decadal morphological evolution of the Yangtze Estuary

NASA Astrophysics Data System (ADS)

Luan, Hualong; Ding, Pingxing; Wang, Zhengbing; Ge, Jianzhong

2017-04-01

Understanding the decadal morphodynamic evolution of estuaries and deltas and their controls is of vital importance regarding management for estuarine function and sustainable development. This work addresses this issue by applying a process-based model system (Delft3D) to hindcast and then forecast the morphodynamic evolution of the Yangtze Estuary at a decadal time scale. Forced by the river and tides, the model considers sand-mud mixture and the seasonal variations of river water discharge and sediment discharge. The morphodynamic model is validated against three periods, i.e., an accretion period (1958-1978), an erosion period (1986-1997) and a recent accretion period with human activities (2002-2010). Model results show good performance with respect to spatial erosion and deposition patterns, sediment volume changes, and hypsometry curves. The model reveals quite different behaviors for mud transport between the dry and wet seasons, which is subject to prescription of river boundary conditions and bed composition. We then define four scenarios to project evolution to 2030 under decreased river inputs and increased relative sea-level. The simulations reveal that overwhelming amount of erosion will likely occur in the inner and mouth bar area of the estuary. Particularly, the mouth zone will shift from net deposition before 2010 to net erosion by 2030, mainly because of decreasing sediment supply. Changes in water discharge have minor effects on the projected trend. Net erosion will be considerable when the sediment supply is extremely low (100 Mt yr-1) due to the abundance of erodible modern sediment in the Yangtze Estuary. Erosion within the mouth bar area may be unexpected, including the deepening of the tidal inlet at East Chongming Mudflat and the formation of a flood channel on the seaward side of Jiuduan Shoal. Overall, the model results provide valuable information for sustainable delta management under changing conditions for both the Yangtze system and

Estimates of long-term water total phosphorus (TP) concentrations in three large shallow lakes in the Yangtze River basin, China.

PubMed

Wu, Pan; Qin, Boqiang; Yu, Ge

2016-03-01

The shallow lakes in the eastern China developed on alluvial plains with high-nutrient sediments, and most overflow into the Yangtze River with short hydraulic residence times, whereas they become eutrophic over long time periods. Assuming strong responses to hydrogeological changes in the basin, we attempted to determine the dynamic eutrophication history of these lakes. Although evaluation models for internal total phosphorus (TP) loading are widely used for deep lakes in Europe and North America, the accuracy of these models for shallow lakes that have smaller water volumes controlled by the geometrical morphology and greater basin area of alluvial plains is unknown. To describe the magnitude of changes in velocity of trophic state for the studied shallow lakes, we first evaluated the P retention model in relation to the major forces driving lake morphology, basin climate, and external discharge and then used the model to estimate changes in TP in three large shallow lakes (Taihu, Chao, and Poyang) over 60 years (1950-2009 AD). The observed levels of TP were verified against the relative error of the three lakes (<6.43 %) and Nash-Sutcliffe coefficients (0.67-0.75). The results showed that the predicted TP concentrations largely increased with hydraulic residence time, especially in extreme drought years, with a generally rising trend in trophic status. The simulated trophic state index showed that lakes Taihu and Poyang became eutrophic in the 1990s, whereas Lake Chao became eutrophic in the 1980s; lakes Taihu and Chao ultimately became hypereutrophic in the 2000s. The analysis suggested that the tropic status of the shallow lakes was affected by both the hydroclimate and geological sedimentation of the Yangtze River basin. This work will contribute to the development of an internal P loading model for further evaluating trophic states.

Characteristics of a Recent and Prehistoric Landslides in the Pine River Valley, BC: a Mapping Effort

NASA Astrophysics Data System (ADS)

Heijenk, R.; Geertsema, M.; Miller, B.; de Jong, S. M.

2015-12-01

Spreads and other low gradient landslides are common in glacial lake sediments in north eastern British Columbia. Both pre and post glacial lake sediments, largely derived from shale bedrock are susceptible to low-gradient landslides. Bank erosion by rivers and streams and high pore pressures, have contributed to the landslides. We used LiDAR for mapping the extent of the glaciolacustrine sediments and map and characterise landslides in the Pine River valley, near Chetwynd, British Columbia. We included metrics such as travel angle, length, area, and elevation to distinguish rotational and translational landslides. We mapped 45 landslides in the Pine River valley distinguishing between rotational and translational landslides. The rotational landslides commonly have a smaller area and smaller travel length than translational landslides. Most rotational slides involved overlying alluvial fans, while most translational slides involved terraces.

Seismic refraction survey in the Great Miami River Valley and vicinity, Montgomery, Warren, and Butler Counties, Ohio

USGS Publications Warehouse

Watkins, Joel S.; Spieker, Andrew M.

1964-01-01

As part of a continuing program to define the thickness and extent of water-bearing sand and gravel deposits in southwestern Ohio, the U.S. Geological Survey, in cooperation with the Ohio Division of Water and The Miami Conservancy District, completed a seismic refraction survey of the Great Miami River valley and adjacent areas between Dayton and Hamilton, Ohio, in the fall of 1963. A similar survey of the adjoining lower Great Miami River and Whitewater River valleys was completed in 1962 (Watkins, 1963; Spieker and Watkins, unpublished data).The area of the survey includes known or inferred portions of an interglacial drainage system which is deeply entrenched into bedrock. Ohio was covered by glaciers at least three times during the Pleistocene epoch. As each glacier melted, rock fragments absorbed by the glacier were transported and deposited in these buried valleys by torrents of meltwater. The total thickness of glacial drift is over 300 feet in some places. Much of the glacial material is highly permeable and saturated with large quantities of water of good quality. The underlying bedrock is virtually impermeable and yields only meager quantities of water. The cities of Dayton, Middletown, Hamilton, and many industries in the Miami River valley rely on wells in the glacial deposits as their principal source of water. The purpose of the present survey is to define the thickness and extent of these important water-bearing formations. Such information will make possible a more accurate evaluation of the area's water resources than has previously have been possible.

View of the Salinas River Valley area south of Monterey Bay, California

NASA Image and Video Library

1973-08-15

SL3-88-004 (July-September 1973) --- A vertical view of the Salinas River Valley area south of Monterey Bay, California area is seen in this Skylab 3 Earth Resources Experiments Package S190-B (five-inch Earth terrain camera) photograph taken from the Skylab space station in Earth orbit. The valley is an irrigated agricultural area, and is indicated by the dark-green and light-gray rectangular patterns in the centre of the picture. The city of Salinas is barely visible under the cloud cover at the top (north) end of the valley. The dark mass on the left (west) side of the valley is the Santa Lucia mountain range. The Big Sur area is on the left and partly covered by clouds. The Diablo Range forms the dark mass in the lower right (southeast) corner of the photograph. The town of Hollister is the gray area in the dark-green rectangular farm tracts which occupy the floor of the San Benito Valley in the upper right (northeast) corner of the photograph. The Salinas River flows northwestward toward Monterey Bay. The towns of Soledad, Greenfield and King City appear as gray areas along U.S. 101 in the Salinas Valley. The geology of the area is complex, and has been racked by several earthquakes resulting from movement along the San Andreas and subsidiary faults. Here, the surface expression of the San Andreas Fault can be traced from a point just west of Hollister at the contrast of dark brown and tan to a point about one inch left of the lower right (southeast) corner of the picture. Subsidiary faults are indicated by the curving trend of the rocks along the right side. The photograph will provide detailed information on land use patterns (Dr. R. Colwell, University of California, Berkeley) and fault tectonics (Dr. P. Merifield, Earth Science Res., Inc. and Dr. M. Abdel-Gawad, Rockwell International). Federal agencies participating with NASA on the EREP project are the Departments of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of

Identifying hotspots and management of critical ecosystem services in rapidly urbanizing Yangtze River Delta Region, China.

PubMed

Cai, Wenbo; Gibbs, David; Zhang, Lang; Ferrier, Graham; Cai, Yongli

2017-04-15

Rapid urbanization has altered many ecosystems, causing a decline in many ecosystem services, generating serious ecological crisis. To cope with these challenges, we presented a comprehensive framework comprising five core steps for identifying and managing hotspots of critical ecosystem services in a rapid urbanizing region. This framework was applied in the case study of the Yangtze River Delta (YRD) Region. The study showed that there was large spatial heterogeneity in the hotspots of ecosystem services in the region, hotspots of supporting services and regulating services aggregately distributing in the southwest mountainous areas while hotspots of provisioning services mainly in the northeast plain, and hotspots of cultural services widespread in the waterbodies and southwest mountainous areas. The regionalization of the critical ecosystem services was made through the hotspot analysis. This study provided valuable information for environmental planning and management in a rapid urbanizing region and helped improve China's ecological redlines policy at regional scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Use of Radar to Improve Rainfall Estimation over the Tennessee and San Joaquin River Valleys

NASA Technical Reports Server (NTRS)

Petersen, Walter A.; Gatlin, Patrick N.; Felix, Mariana; Carey, Lawrence D.

2010-01-01

This slide presentation provides an overview of the collaborative radar rainfall project between the Tennessee Valley Authority (TVA), the Von Braun Center for Science & Innovation (VCSI), NASA MSFC and UAHuntsville. Two systems were used in this project, Advanced Radar for Meteorological & Operational Research (ARMOR) Rainfall Estimation Processing System (AREPS), a demonstration project of real-time radar rainfall using a research radar and NEXRAD Rainfall Estimation Processing System (NREPS). The objectives, methodology, some results and validation, operational experience and lessons learned are reviewed. The presentation. Another project that is using radar to improve rainfall estimations is in California, specifically the San Joaquin River Valley. This is part of a overall project to develop a integrated tool to assist water management within the San Joaquin River Valley. This involves integrating several components: (1) Radar precipitation estimates, (2) Distributed hydro model, (3) Snowfall measurements and Surface temperature / moisture measurements. NREPS was selected to provide precipitation component.

Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa

USGS Publications Warehouse

Bettis, E. Arthur; Baker, R.G.; Nations, B.K.; Benn, D.W.

1990-01-01

A fossil pecan, Carya illinoensis (Wang.) K. Koch, from floodplain sediments of the Mississippi River near Muscatine, Iowa, was accelerator-dated at 7280 ?? 120 yr B.P. This discovery indicates that pecan was at or near its present northern limit by that time. Carya pollen profiles from the Mississippi River Trench indicate that hickory pollen percentages were much higher in the valley than at upland locations during the early Holocene. Pecan, the hickory with the most restricted riparian habitat, is the likely candidate for producing these peaks in Carya pollen percentages. Therefore, pecan may have reached its northern limit as early as 10,300 yr B.P. Its abundance in Early Archaic archaeological sites and the co-occurrence of early Holocene Carya pollen peaks with the arrival of the Dalton artifact complex in the Upper Mississippi Valley suggest that humans may have played a role in the early dispersal of pecan. ?? 1990.

Digital Map of Surficial Geology, Wetlands, and Deepwater Habitats, Coeur d'Alene River Valley, Idaho

USGS Publications Warehouse

Bookstrom, Arthur A.; Box, Stephen E.; Jackson, Berne L.; Brandt, Theodore R.; Derkey, Pamela D.; Munts, Steven R.

1999-01-01

The Coeur d'Alene (CdA) River channel and its floodplain in north Idaho are mostly covered by metal-enriched sediments, partially derived from upstream mining, milling and smelting wastes. Relative to uncontaminated sediments of the region, metal-enriched sediments are highly enriched in silver, lead, zinc, arsenic, antimony and mercury, copper, cadmium, manganese, and iron. Widespread distribution of metal-enriched sediments has resulted from over a century of mining in the CdA mining district (upstream), poor mine-waste containment practices during the first 80 years of mining, and an ongoing series of over-bank floods. Previously deposited metal-enriched sediments continue to be eroded and transported down-valley and onto the floodplain during floods. The centerpiece of this report is a Digital Map Surficial Geology, Wetlands and Deepwater Habitats of the Coeur d'Alene (CdA) River valley (sheets 1 and 2). The map covers the river, its floodplain, and adjacent hills, from the confluence of the North and South Forks of the CdA River to its mouth and delta front on CdA Lake, 43 linear km (26 mi) to the southwest (river distance 58 km or 36 mi). Also included are the following derivative theme maps: 1. Wetland System Map; 2. Wetland Class Map; 3. Wetland Subclass Map; 4. Floodplain Map; 5. Water Regime Map; 6. Sediment-Type Map; 7. Redox Map; 8. pH Map; and 9. Agricultural Land Map. The CdA River is braided and has a cobble-gravel bottom from the confluence to Cataldo Flats, 8 linear km (5 mi) down-valley. Erosional remnants of up to four alluvial terraces are present locally, and all are within the floodplain, as defined by the area flooded in February of 1996. High-water (overflow) channels and partly filled channel scars braid across some alluvial terraces, toward down-valley marshes and (or) oxbow ponds, which drain back to the river. Near Cataldo Flats, the river gradient flattens, and the river coalesces into a single channel with a large friction

Aquifer-test results, direction of ground-water flow, and 1984-90 annual ground-water pumpage for irrigation, lower Big Lost River Valley, Idaho

USGS Publications Warehouse

Bassick, M.D.; Jones, M.L.

1992-01-01

The study area (see index map of Idaho), part of the Big Lost River drainage basin, is at the northern side of the eastern Snake River Plain. The lower Big Lost River Valley extends from the confluence of Antelope Creek and the Big Lost River to about 4 mi south of Arco and encompasses about 145 mi2 (see map showing water-level contours). The study area is about 18 mi long and, at its narrowest, 4 mi wide. Arco, Butte City, and Moore, with populations of 1,016, 59, and 190, respectively, in 1990, are the only incorporated towns. The entire study area, except the extreme northwestern part, is in Butte City. The study area boundary is where alluvium and colluvium pinch out and abut against the White Knob Mountains (chiefly undifferentiated sedimentary rock with lesser amounts of volcanic rock) on the west and the Lost River Range (chiefly sedimentary rock) on the east. Gravel and sand in the valley fill compose the main aquifer. The southern boundary is approximately where Big Lost River valley fill intercalates with or abuts against basalt of the Snake River Group. Spring ground-water levels and flow in the Big Lost River depend primarily on temperature and the amount and timing of precipitation within the entire drainage basin. Periods of abundant water supply and water shortages are, therefore, related to the amount of annual precipitation. Surface reservoir capacity in the valley (Mackay Reservoir, about 20 mi northwest of Moore) is only 20 percent of the average annual flow of the Big Lost River (Crosthwaite and others, 1970, p. 3). Stored surface water is generally unavailable for carryover from years of abundant water supply to help relieve drought conditions in subsequent years. Many farmers have drilled irrigation wells to supplement surface-water supplies and to increase irrigated acreage. Average annual flow of the Big Lost River below Mackay Reservoir near Mackay (gaging station 13127000, not shown) in water years 1905, 1913-14, and 1920-90 was about 224

A weighted higher-order network analysis of fine particulate matter (PM2.5) transport in Yangtze River Delta

NASA Astrophysics Data System (ADS)

Wang, Yufang; Wang, Haiyan; Zhang, Shuhua

2018-04-01

Specification of PM2.5 transmission characteristics is important for pollution control, policymaking and prediction. In this paper, we propose weights for motif instances, thereby to implement a weighted higher-order clustering algorithm for a weighted, directed PM2.5 network in the Yangtze River Delta (YRD) of China. The weighted, directed network we create in this paper includes information on meteorological conditions of wind speed and wind direction, plus data on geographic distance and PM2.5 concentrations. We aim to reveal PM2.5 mobility between cities in the YRD. Major potential PM2.5 contributors and closely interacted clusters are identified in the network of 178 air quality stations in the YRD. To our knowledge, it is the first work to incorporate weight information into the higher-order network analysis to study PM2.5 transport.

Shifts in river-floodplain relationship reveal the impacts of river regulation: A case study of Dongting Lake in China

NASA Astrophysics Data System (ADS)

Lu, Cai; Jia, Yifei; Jing, Lei; Zeng, Qing; Lei, Jialin; Zhang, Shuanghu; Lei, Guangchun; Wen, Li

2018-04-01

Better understanding of the dynamics of hydrological connectivity between river and floodplain is essential for the ecological integrity of river systems. In this study, we proposed a regime-switch modelling (RSM) framework, which integrates change point analysis with dynamic linear regression, to detect and date change points in linear regression, and to quantify the relative importance of natural variations and anthropogenic disturbances. The approach was applied to the long-term hydrological time series to investigate the evolution of river-floodplain relation in Dongting Lake in the last five decades, during which the Yangtze River system experienced unprecedented anthropogenic manipulations. Our results suggested that 1) there were five distinct regimes during which the influence of inflows and local climate on lake water level changed significantly. The detected change points were well corresponding to the major events occurred upon the Yangtze; 2) although the importance of inflows from the Yangtze was greater than that of the tributaries flows over the five regimes, the relative contribution gradually decreased from regime 1 to regime 5. The weakening of hydrological forcing from the Yangtze was mainly attributed to the reduction in channel capacity resulting from sedimentation in the outfalls and water level dropping caused by river bed scour in the mainstream; 3) the effects of local climate was much smaller than these of inflows; and 4) since the operation of The Three Gorges Dam in 2006, the river-floodplain relationship entered a new equilibrium in that all investigated variables changed synchronously in terms of direction and magnitude. The results from this study reveal the mechanisms underlying the alternated inundation regime in Dongting Lake. The identified change points, some of which have not been previously reported, will allow a reappraisal of the current dam and reservoir operation strategies not only for flood/drought risk management but

Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations

USGS Publications Warehouse

Brown, Larry R.; Bauer, Marissa L.

2010-01-01

Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologic infrastructure and management affect streamflow characteristics of rivers in the Central Valley, California and discuss those characteristics in the context of habitat requirements of native and alien fishes. We evaluated the effects of water management by comparing observed discharges with estimated discharges assuming no water management ("full natural runoff"). Rivers in the Sacramento River drainage were characterized by reduced winter–spring discharges and augmented discharges in other months. Rivers in the San Joaquin River drainage were characterized by reduced discharges in all months but particularly in winter and spring. Two largely unaltered streams had hydrographs similar to those based on full natural runoff of the regulated rivers. The reduced discharges in the San Joaquin River drainage streams are favourable for spawning of many alien species, which is consistent with observed patterns of fish distribution and abundance in the Central Valley. However, other factors, such as water temperature, are also important to the relative success of native and alien resident fishes. As water management changes in response to climate change and societal demands, interdisciplinary programs of research and monitoring will be essential for anticipating effects on fishes and to avoid unanticipated ecological outcomes.

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

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

Feng, Huan; Zhang, Weiguo; Qian, Yu

2016-06-15

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn inPhragmites australisroot system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils.Phragmites australissamples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and thatmore » other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

DOE PAGES

Feng, Huan; Zhang, Weiguo; Qian, Yu; ...

2016-06-15

This paper investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in themore » root epidermis and that other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

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

Feng, Huan; Zhang, Weiguo; Qian, Yu

This paper investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in themore » root epidermis and that other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Three Gorges Dam alters the Changjiang (Yangtze) river water cycle in the dry seasons: Evidence from H-O isotopes.

PubMed

Deng, Kai; Yang, Shouye; Lian, Ergang; Li, Chao; Yang, Chengfan; Wei, Hailun

2016-08-15

As the largest hydropower project in the world, the Three Gorges Dam (TGD) has attracted great concerns in terms of its impact on the Changjiang (Yangtze) River and coastal marine environments. In this study, we measured or collected the H-O isotopic data of river water, groundwater and precipitation in the mid-lower Changjiang catchment during the dry seasons of recent years. The aim was to investigate the changes of river water cycle in response to the impoundment of the TGD. Isotopic evidences suggested that the mid-lower Changjiang river water was ultimately derived from precipitation, but dominated by the mixing of different water masses with variable sources and isotopic signals as well. The isotopic parameter "deuterium excess" (d-excess) yielded large fluctuations along the mid-lower mainstream during the initial stage of the TGD impoundment, which was inherited from the upstream water with inhomogeneous isotopic signals. However, as the reservoir water level rising to the present stage, small variability of d-excess was observed along the mid-lower mainstream. This discrepancy could be explained that the TGD impoundment had significantly altered the water cycle downstream the dam, with the rising water level increasing the residence time and enhancing the mixing of reservoir water derived from upstream. This eventually resulted in the homogenization of reservoir water, and thus small fluctuations of d-excess downstream the dam after the quasi-normal stage (2008 to present). We infer that the retention effect of large reservoirs has greatly buffered the d-excess natural variability of water cycle in large river systems. Nevertheless, more research attention has to be paid to the damming effect on the water cycle in the river, estuarine and coastal areas, especially during the dry seasons. Copyright © 2016 Elsevier B.V. All rights reserved.

[Speciation and Risk Characteristics of Heavy Metals in the Sediments of the Yangtze Estuary].

PubMed

Yin, Su; Feng, Cheng-hong; Li, Yang-yang; Yin, Li-feng; Shen, Zhen-yao

2016-03-15

Based on the investigation on the distribution of total contents and speciation of 8 heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in the surface sediments at 14 typical sites of the Yangtze Estuary during three hydrological seasons ( wet, normal, and dry seasons) , this study applied equilibrium partitioning approach to build the sediment quality guidelines (SQGs) of the Yangtze Estuary, and assessed ecological risks of the heavy metals. The relationship between ecological risk and speciation of heavy metals was also revealed. The results showed that, except for Cd, the residual fraction was the main speciation of heavy metals, especially for As, Cr and Hg, their residual fraction proportions were all over 90%. The sediment quality guidelines of the Yangtze Estuary for As, Cd, Cr, Cu, Hg, Ni, Pb, Zn were 43.29, 0.672, 79.65, 19.08, 0.569, 339.09, 30.87, 411.36 µg · g⁻¹, respectively. Cu had the highest ecological risk to aquatic organisms. The upstream of Yangtze Estuary was mainly affected by Yangtze River runoff, where the risks were relatively high in wet season and relatively low in normal and dry seasons. However, the downstream of the estuary was mainly affected by municipal sewage of cities like Shanghai, where the risks were relatively high, especially in normal and dry seasons. There were three different relationships between the ecological risks and speciation of the eight heavy metals.

Salinity Trends in the Upper Colorado River Basin Upstream From the Grand Valley Salinity Control Unit, Colorado, 1986-2003

USGS Publications Warehouse

Leib, Kenneth J.; Bauch, Nancy J.

2008-01-01

In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or 'units' of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in western Colorado. The U. S. Geological Survey has done extensive studies and research in the Grand Valley Salinity Control Unit that provide information to aid the U.S. Bureau of Reclamation and the Natural Resources Conservation Service in determining where salinity-control work may provide the best results, and to what extent salinity-control work was effective in reducing salinity concentrations and loads in the Colorado River. Previous studies have indicated that salinity concentrations and loads have been decreasing downstream from the Grand Valley Salinity Control Unit, and that the decreases are likely the result of salinity control work in these areas. Several of these reports; however, also document decreasing salinity loads upstream from the Grand Valley Salinity Control Unit. This finding was important because only a small amount of salinity-control work was being done in areas upstream from the Grand Valley Salinity Control Unit at the time the findings were reported (late 1990?s). As a result of those previous findings, the U.S. Bureau of Reclamation entered into a cooperative agreement with the U.S. Geological Survey to investigate salinity trends in selected areas bracketing the Grand Valley Salinity Control Unit and regions upstream from the Grand Valley Salinity Control Unit. The results of the study indicate that salinity loads were decreasing upstream from the Grand Valley Salinity Control Unit from 1986 through 2003, but the rates of decrease have slowed during the last 10 years. The average rate of decrease in salinity load upstream from the Grand Valley

New evidence of Yangtze delta recession after closing of the Three Gorges Dam

PubMed Central

Luo, X. X.; Yang, S. L.; Wang, R. S.; Zhang, C. Y.; Li, P.

2017-01-01

Many deltas are likely undergoing net erosion because of rapid decreases in riverine sediment supply and rising global sea levels. However, detecting erosion in subaqueous deltas is usually difficult because of the lack of bathymetric data. In this study, by comparing bathymetric data between 1981 and 2012 and surficial sediment grain sizes from the Yangtze subaqueous delta front over the last three decades, we found severe erosion and significant sediment coarsening in recent years since the construction of Three Gorges Dam (TGD), the largest dam in the world. We attributed these morphological and sedimentary variations mainly to the human-induced drastic decline of river sediment discharge. Combined with previous studies based on bathymetric data from different areas of the same delta, we theorize that the Yangtze subaqueous delta is experiencing overall (net) erosion, although local accumulation was also noted. We expect that the Yangtze sediment discharge will further decrease in the near future because of construction of new dams and delta recession will continue to occur. PMID:28145520

A multidisciplinary, integrated approach for the elimination of schistosomiasis: a longitudinal study in a historically hyper-endemic region in the lower reaches of the Yangtze River, China from 2005 to 2014.

PubMed

Sun, Le-Ping; Wang, Wei; Zuo, Yin-Ping; Hong, Qing-Biao; Du, Guang-Lin; Ma, Yu-Cai; Wang, Jian; Yang, Guo-Jing; Zhu, Dao-Jian; Liang, You-Sheng

2017-03-14

Although great success has been achieved, schistosomiasis remains a major public health concern in China, and the remaining core endemic regions are concentrated along the middle and lower reaches of the Yangtze River. In this longitudinal study, we evaluated the effectiveness of a multidisciplinary, integrated approach for schistosomiasis elimination in a historically hyper-endemic region in the lower reaches of the Yangtze River, China over the 10-year period from 2005 through 2014. A three-step roadmap for schistosomiasis elimination was designed in the study site, and multidisciplinary, integrated interventions were implemented by the health, agriculture, water resources development, land and resources, and forestry sectors from 2005 to 2014, including chemotherapy for infected individuals, health education, management of the source of Schistosoma japonicum infection, and intermediate host snail control. The annual number of schistosomiasis patients, S. japonicum infection in humans, bovines and Oncomelania hupensis snails, and water infectivity were observed to assess the effectiveness of the multidisciplinary, integrated approach for the elimination of schistosomiasis. There was a tendency towards a gradual decline in both the number of schistosomiasis cases and the prevalence of S. japonicum human infection across the study period from 2005 through 2014. No S. japonicum human infection was detected since 2012, and no acute infection was seen since 2006. During the study period, no infection was found in bovines, and a 0.03% overall infection rate was observed in O. hupensis snails. Since 2009, no infected snails were identified, and the area of both snail habitats and infected snail habitats appeared a reduction over the study period. Following the 3-year multidisciplinary, integrated control, infection control was achieved, and transmission control was achieved after 6-year implementation, with all infected snails and water infectivity eliminated; in

75 FR 7286 - Rappahannock River Valley National Wildlife Refuge, Caroline, Essex, King George, Lancaster...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R5-R-2009-N203; BAC-4311-K9-S3] Rappahannock River Valley National Wildlife Refuge, Caroline, Essex, King George, Lancaster, Middlesex, Richmond, and Westmoreland Counties, VA AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of...

Antibiotics in the agricultural soils from the Yangtze River Delta, China.

PubMed

Sun, Jianteng; Zeng, Qingtao; Tsang, Daniel C W; Zhu, L Z; Li, X D

2017-12-01

This study focused on the occurrence and spatial distribution of 13 common antibiotics in the agricultural soils of the Yangtze River Delta (YRD), China. Antibiotics were detected in all the 241 soil samples (i.e., 100% detection rate) with the total concentrations ranging from 4.55 to 2,010 ng/g dry weight. The concentrations of three antibiotic classes decreased in the order: quinolones (mean 48.8 ng/g) > tetracyclines (mean 34.9 ng/g) > sulfonamides (mean 2.35 ng/g). Ciprofloxacin was the prevalent compound with a mean concentration of 27.7 ng/g, followed by oxytetracycline (mean of 18.9 ng/g). A distinct spatial distribution was observed, where high concentrations of antibiotics were detected in the sites adjacent to the livestock and poultry farms. The potential sources of antibiotics in the agricultural soils were the application of manure and wastewater irrigation in this region. Risk assessment for single antibiotic compound indicated that tetracyclines and quinolones could pose a potential risk, in which doxycycline and ciprofloxacin had the most severe ecological effect in the agricultural soils. Antibiotic resistance genes (ARGs), such as tetA, sulI, and qnrS, were detected in 15 analyzed soil samples, and sulI showed significant correlations with quinolones, tetracyclines, copper, and zinc. Further studies on the distribution of other ARGs in agricultural soil at a region-scale are needed for the risk management of extensively used antibiotics and major ARGs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa*1

NASA Astrophysics Data System (ADS)

Bettis, E. Arthur; Baker, Richard G.; Nations, Brenda K.; Benn, David W.

1990-01-01

A fossil pecan, Carya illinoensis (Wang.) K. Koch, from floodplain sediments of the Mississippi River near Muscatine, Iowa, was accelerator-dated at 7280 ± 120 yr B.P. This discovery indicates that pecan was at or near its present northern limit by that time. Carya pollen profiles from the Mississippi River Trench indicate that hickory pollen percentages were much higher in the valley than at upland locations during the early Holocene. Pecan, the hickory with the most restricted riparian habitat, is the likely candidate for producing these peaks in Carya pollen percentages. Therefore, pecan may have reached its northern limit as early as 10,300 yr B.P. Its abundance in Early Archaic archaeological sites and the co-occurrence of early Holocene Carya pollen peaks with the arrival of the Dalton artifact complex in the Upper Mississippi Valley suggest that humans may have played a role in the early dispersal of pecan.

Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A

Treesearch

Diane De Steven; Stephen P. Faulkner; Bobby D. Keeland; Michael J. Baldwin; John W. McCoy; Steven C. Hughes

2015-01-01

In the Mississippi River Alluvial Valley (MAV), complete alteration of river-floodplain hydrology allowed for widespread conversion of forested bottomlands to intensive agriculture, resulting in nearly 80% forest loss. Governmental programs have attempted to restore forest habitat and functions within this altered landscape by the methods of tree planting (...

Geological Carbon Sequestration in the Ohio River Valley: An Evaluation of Possible Target Formations

NASA Astrophysics Data System (ADS)

Dalton, T. A.; Daniels, J. J.

2009-12-01

The development of geological carbon sequestration within the Ohio River Valley is of major interest to the national electricity and coal industries because the Valley is home to a heavy concentration of coal-burning electricity generation plants and the infrastructure is impossible to eliminate in the short-term. It has been determined by Ohio's politicians and citizenry that the continued use of coal in this region until alternative energy supplies are available will be necessary over the next few years. Geologic sequestration is the only possible means of keeping the CO2 out of the atmosphere in the region. The cost of the sequestration effort greatly decreases CO2 emissions by sequestering CO2 directly on site of these plants, or by minimizing the distance between fossil-fueled generation and sequestration (i.e., by eliminating the cost of transportation of supercritical CO2 from plant to sequestration site). Thus, the practicality of CO2 geologic sequestration within the Ohio River Valley is central to the development of such a commercial effort. Though extensive work has been done by the Regional Partnerships of the DOE/NETL in the characterization of general areas for carbon sequestration throughout the nation, few projects have narrowed their focus into a single geologic region in order to evaluate the sites of greatest commercial potential. As an undergraduate of the Earth Sciences at Ohio State, I have engaged in thorough research to obtain a detailed understanding of the geology of the Ohio River Valley and its potential for commercial-scale carbon sequestration. Through this research, I have been able to offer an estimate of the areas of greatest interest for CO2 geologic sequestration. This research has involved petrological, mineralogical, geochemical, and geophysical analyses of four major reservoir formations within Ohio—the Rose Run, the Copper Ridge, the Clinton, and the Oriskany—along with an evaluation of the possible effects of injection

Hydrogeology of the Susquehanna River valley-fill aquifer system and adjacent areas in eastern Broome and southeastern Chenango Counties, New York

USGS Publications Warehouse

Heisig, Paul M.

2012-01-01

The hydrogeology of the valley-fill aquifer system along a 32-mile reach of the Susquehanna River valley and adjacent areas was evaluated in eastern Broome and southeastern Chenango Counties, New York. The surficial geology, inferred ice-marginal positions, and distribution of stratified-drift aquifers were mapped from existing data. Ice-marginal positions, which represent pauses in the retreat of glacial ice from the region, favored the accumulation of coarse-grained deposits whereas more steady or rapid ice retreat between these positions favored deposition of fine-grained lacustrine deposits with limited coarse-grained deposits at depth. Unconfined aquifers with thick saturated coarse-grained deposits are the most favorable settings for water-resource development, and three several-mile-long sections of valley were identified (mostly in Broome County) as potentially favorable: (1) the southernmost valley section, which extends from the New York–Pennsylvania border to about 1 mile north of South Windsor, (2) the valley section that rounds the west side of the umlaufberg (an isolated bedrock hill within a valley) north of Windsor, and (3) the east–west valley section at the Broome County–Chenango County border from Nineveh to East of Bettsburg (including the lower reach of the Cornell Brook valley). Fine-grained lacustrine deposits form extensive confining units between the unconfined areas, and the water-resource potential of confined aquifers is largely untested. Recharge, or replenishment, of these aquifers is dependent not only on infiltration of precipitation directly on unconfined aquifers, but perhaps more so from precipitation that falls in adjacent upland areas. Surface runoff and shallow groundwater from the valley walls flow downslope and recharge valley aquifers. Tributary streams that drain upland areas lose flow as they enter main valleys on permeable alluvial fans. This infiltrating water also recharges valley aquifers. Current (2012) use of

High-precision U-Pb geochronology in the Minnesota River Valley subprovince and its bearing on the Neoarchean to Paleoproterozoic evolution of the southern Superior Province

USGS Publications Warehouse

Schmitz, M.D.; Bowring, S.A.; Southwick, D.L.; Boerboom, Terrence; Wirth, K.R.

2006-01-01

High-precision U-Pb ages have been obtained for high-grade gneisses, late-kinematic to postkinematic granitic plutons, and a crosscutting mafic dike of the Archean Minnesota River Valley tectonic subprovince, at the southern ramparts of the Superior craton of North America. The antiquity of the Minnesota River Valley terranes is confirmed by a high-precision U-Pb zircon age of 3422 ?? 2 Ma for a tonalitic phase of the Morton Gneiss. Voluminous, late-kinematic monzogranites of the Benson (Ortonville granite) and Morton (Sacred Heart granite) blocks yield identical crystallization ages of 2603 ?? 1 Ma, illustrating the synchrony and rapidity of deep crustal melting and plutonism throughout the Minnesota River Valley terranes. Postkinematic, 2591 ?? 2 Ma syenogranites and aplitic dikes in both blocks effectively constrain the final penetrative deformation of the Minnesota River Valley subprovince. Monazite growth from 2609 to 2595 Ma in granulitic paragneisses of the Benson and Montevideo blocks is interpreted to record prograde to peak granulite facies metamorphic conditions associated with crustal thickening and magmatism. Neoarchean metamorphism and plutonism are interpreted to record the timing of collisional accretion and terminal suturing of the Mesoarchean continental Minnesota River Valley terranes to the southern margin of the Superior Province, along the western Great Lakes tectonic zone. Subsequent Paleoproterozoic rifting of this margin is recorded by voluminous basaltic dike intrusion, expressed in the Minnesota River Valley by major WNW-trending tholeiitic diabase dikes dated at 2067 ?? 1 Ma, only slightly younger than the structurally and geochemically similar 2077 ?? 4 Ma Fort Frances (Kenora-Kabetogama) dike swarm of northern Minnesota and adjoining Canada. ?? 2006 Geological Society of America.

Influence of Tectonics on the Channel Pattern of Alaknanda River in Srinagar Valley (Garhwal Himalaya)

NASA Astrophysics Data System (ADS)

Datt, Devi

2017-04-01

This paper describes the results of a continuing investigation of tectonic influence on channel pattern and morphology of Alaknanda River in Lesser Garhwal Himalaya, Uttarakhand, India. Extensive field investigations using conventional methods supported by topographical sheets and remote sensing data (LISS IV), were undertaken.The results are classified into three sections :- tectonics, channel pattern and impact of tectonics on channel pattern. The channel length is divided into 8 meanders sets of 3 segments from Supana to Kirtinagar. Thereafter, a litho-tectonic map of the Srinagar valley was prepared. The style of active tectonics on deformation and characterization of fluvial landscape was investigated on typical strike-slip transverse faults near the zone of North Almora Thrust (NAT). NAT is a major tectonic unit of the Lesser Himalaya which passes through the northern margin from NW to SE direction.. The structural and lithological controls on the Alaknanda River system in Srinagar valley are reflected on distinct drainage patterns, abrupt change in flow direction, incised meandering, offset river channels, straight river lines, palaeo-channels, multi levels of terraces, knick points and pools in longitudinal profile. The results of the study show that the sinuosity index of the river is 1.35. Transverse faulting is very common along the NAT. An earlier generation of linear tectonic features were displaced by the latter phase of deformation. Significant deviations were observed in river channel at deformation junctions. Moreover, all 8 sets of meanders are strongly influenced by tectonic features. The meandering course is, thereby, correlated with tectonic features. It is shown that the river channel is strongly influenced by the tectonic features in the study area. Key Words: Tectonic, Meander, Channel pattern, deformation, Knick point.

Land Capability Potential Index (LCPI) for the Lower Missouri River Valley

USGS Publications Warehouse

Jacobson, Robert B.; Chojnacki, Kimberly A.; Reuter, Joanna M.

2007-01-01

The Land Capability Potential Index (LCPI) was developed to serve as a relatively coarse-scale index to delineate broad land capability classes in the valley of the Lower Missouri River. The index integrates fundamental factors that determine suitability of land for various uses, and may provide a useful mechanism to guide land-management decisions. The LCPI was constructed from integration of hydrology, hydraulics, land-surface elevations, and soil permeability (or saturated hydraulic conductivity) datasets for an area of the Lower Missouri River, river miles 423–670. The LCPI estimates relative wetness based on intersecting water-surface elevations, interpolated from measurements or calculated from hydraulic models, with a high-resolution land-surface elevation dataset. The potential for wet areas to retain or drain water is assessed using soil-drainage classes that are estimated from saturated hydraulic conductivity of surface soils. Terrain mapping that delineates areas with convex, concave, and flat parts of the landscape provides another means to assess tendency of landscape patches to retain surface water.

Innovative trend analysis of annual and seasonal air temperature and rainfall in the Yangtze River Basin, China during 1960-2015

NASA Astrophysics Data System (ADS)

Cui, Lifang; Wang, Lunche; Lai, Zhongping; Tian, Qing; Liu, Wen; Li, Jun

2017-11-01

The variation characteristics of air temperature and precipitation in the Yangtze River Basin (YRB), China during 1960-2015 were analysed using a linear regression (LR) analysis, a Mann-Kendall (MK) test with Sen's slope estimator and Sen's innovative trend analysis (ITA). The results showed that the annual maximum, minimum and mean temperature significantly increased at the rate of 0.15°C/10yr, 0.23°C/10yr and 0.19°C/10yr, respectively, over the whole study area during 1960-2015. The warming magnitudes for the above variables during 1980-2015 were much higher than those during 1960-2015:0.38°C/10yr, 0.35°C/10yr and 0.36°C/10yr, respectively. The seasonal maximum, minimum and mean temperature significantly increased in the spring, autumn and winter seasons during 1960-2015. Although the summer temperatures also increased at some extent, only the minimum temperature showed a significant increasing trend. Meanwhile, the highest rate of increase of seasonal mean temperature occurred in winter (0.24°C/10yr) during 1960-2015 and spring (0.50°C/10yr) during 1980-2015, which indicated that the significant warming trend for the whole YRB could be attributed to the remarkable temperature increases in winter and spring months. However, both the annual and seasonal warming magnitudes showed large regional differences, and a higher warming rate was detected in the eastern YRB and the western source region of the Yangtze River on the Qinghai-Tibetan Plateau (QTP). Additionally, annual precipitation increased by approximately 12.02 mm/10yr during 1960-2015 but decreased at the rate of 19.63 mm/10yr during 1980-2015. There were decreasing trends for precipitation in all four seasons since 1980 in the YRB, and a significant increasing trend was only detected in summer since 1960 (12.37 mm/10yr). Overall, a warming-wetting trend was detected in the south-eastern and north-western YRB, while there was a warming-drying trend in middle regions.

Reconnaissance of the chemical quality of water in western Utah, Part I: Sink Valley area, drainage basins of Skull, Rush, and Government Creek Valleys, and the Dugway Valley-Old River Bed area

USGS Publications Warehouse

Waddell, K.M.

1967-01-01

This report presents data collected during the first part of an investigation that was started in 1963 by the U.S. Geological Survey in cooperation with the Utah Geological and Mineralogical Survey. The investigation has the purpose of providing information about the chemical quality of water in western Utah that will help interested parties to evaluate the suitability of the water for various uses in a broad area of Utah where little information of this type previously has been available. The area studied includes the Sink Valley area, the drainage basins of Skull, Rush, and Government Creek Valleys, and the Dugway Valley-Old River Bed area (fig. 1). Osamu Hattori and G. L. Hewitt started the investigation, and the author completed it and prepared the report.

Flood-Inundation Maps for the Meramec River at Valley Park and at Fenton, Missouri, 2017

DOT National Transportation Integrated Search

2017-01-01

Two sets of digital flood-inundation map libraries that spanned a combined 16.7-mile reach of the Meramec River that extends upstream from Valley Park, Missouri, to downstream from Fenton, Mo., were created by the U.S. Geological Survey (USGS) in coo...

Using a novel flood prediction model and GIS automation to measure the valley and channel morphology of large river networks

EPA Science Inventory

Traditional methods for measuring river valley and channel morphology require intensive ground-based surveys which are often expensive, time consuming, and logistically difficult to implement. The number of surveys required to assess the hydrogeomorphic structure of large river n...

The environmental conditionings of the location of primeval settlements in the Wieprz River valley

NASA Astrophysics Data System (ADS)

Kozieł, Marcin; Kozieł, Wojciech

2012-01-01

The Wieprz River along the section currently occupied by the Nadwieprzański Landscape Park (NLP) constituted a convenient place of human settlement from the moment of retreat of the last ice sheet. Depending on the types of economy preferred by representatives of individual archaeological cultures, the river valley from Spiczyn to Dorohucza offered continuous access to water. This obviously gained additional importance from the moment of appearance of Neolithic cultures, particularly the Globular Amphora culture and Corded Ware culture with semi-nomadic style of life, dealing with breeding. Neolithic hunters-gatherers exploited the animal resources available in the river and its vicinity. The further role of fishing, i.e. providing a diet element or supplementation already in the conditions of agricultural-breeding economy, seems to be evidenced by findings of fishing hooks at Lusatian and Wielbark sites. Another factor affecting the location of settlements in NLP was also its close vicinity to the crops of the Rejowiec flint. According to archaeologists, this is particularly obvious in the case of the Late Palaeolithic and the turn of the Neolithic and Bronze Age. The communication function of the river could also be of importance: in the case of seasonal animal migrations of animals and hunters (Late Palaeolithic); livestock and shepherds (Globular Amphora culture and Corded Ware culture); or people alone (migration of the population of the Wielbark culture to the Red Sea). The fact that a commercial trail fragment was located along the Wieprz River is probably evidenced by the abundance of import from various parts of Europe at site 53 in Spiczyn. Fertile soils (black soils, silt-peat soils) prevailing in the valley also favoured the settlement of cultures with an agricultural-breeding model of economy, providing good conditions for horticulture. Meadows near the river could be used as pastures.

Morphological adjustments in a meandering reach of the middle Yangtze River caused by severe human activities

NASA Astrophysics Data System (ADS)

Zhou, Meirong; Xia, Junqiang; Lu, Jinyou; Deng, Shanshan; Lin, Fenfen

2017-05-01

In the past 50 years, the Shishou reach in the middle Yangtze River underwent significant channel evolution owing to the implementation of an artificial cutoff, the construction of bank revetment works and the operation of the Three Gorges Project (TGP). Based on the measured hydrological data and topographic data, the processes of channel evolution in this reach were investigated mainly from the adjustments in planform and cross-sectional geometries. The variation in planform geometry obtained in this study indicates that (i) the artificial cutoff at Zhongzhouzi caused the river regime to adjust drastically, with the mean rate of thalweg migration at reach scale of 42.0 m/a over the period 1966-1975; (ii) then the effect of this artificial cutoff reduced gradually, with the mean migration rate decreasing to < 30 m/a in 1975-1993, while it increased to > 40 m/a owing to the occurrence of high water levels in 1993-1998; and (iii) the average annual rate of thalweg migration decreased to 29.3 m/a because of the impacts of various bank protection engineering and the TGP operation during the period 2002-2015. However, remarkable thalweg migration processes still occurred in local regions after the TGP operation, which resulted in significant bankline migration in local reaches of Beimenkou, Shijiatai, and Tiaoxiankou. In addition, the adjustments of bankfull channel geometry were investigated at section and reach scales after the TGP operation. Calculated results show that lateral channel migration in this reach was restricted by various river regulation works and that channel evolution was mainly characterized by an increase in bankfull depth and cross-sectional area. Empirical relationships were developed between the reach-scale bankfull dimensions (depth and area), the bankfull widths at specified sections, and the previous 5-year average fluvial erosion intensity during flood seasons, with high correlation degrees between them being obtained.

Stream seepage and groundwater levels, Wood River Valley, south-central Idaho, 2012-13

USGS Publications Warehouse

Bartolino, James R.

2014-01-01

Stream discharge and water levels in wells were measured at multiple sites in the Wood River Valley, south-central Idaho, in August 2012, October 2012, and March 2013, as a component of data collection for a groundwater-flow model of the Wood River Valley aquifer system. This model is a cooperative and collaborative effort between the U.S. Geological Survey and the Idaho Department of Water Resources. Stream-discharge measurements for determination of seepage were made during several days on three occasions: August 27–28, 2012, October 22–24, 2012, and March 27–28, 2013. Discharge measurements were made at 49 sites in August and October, and 51 sites in March, on the Big Wood River, Silver Creek, their tributaries, and nearby canals. The Big Wood River generally gains flow between the Big Wood River near Ketchum streamgage (13135500) and the Big Wood River at Hailey streamgage (13139510), and loses flow between the Hailey streamgage and the Big Wood River at Stanton Crossing near Bellevue streamgage (13140800). Shorter reaches within these segments may differ in the direction or magnitude of seepage or may be indeterminate because of measurement uncertainty. Additional reaches were measured on Silver Creek, the North Fork Big Wood River, Warm Springs Creek, Trail Creek, and the East Fork Big Wood River. Discharge measurements also were made on the Hiawatha, Cove, District 45, Glendale, and Bypass Canals, and smaller tributaries to the Big Wood River and Silver Creek. Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established by the U.S. Geological Survey in 2006. Maps of the October 2012 water-table altitude in the unconfined aquifer and the potentiometric-surface altitude of the confined aquifer have similar topology to those on maps of October 2006 conditions. Between October 2006 and October 2012, water-table altitude in the unconfined aquifer rose by

SRTM Perspective View with Landsat Overlay: Santa Paula, and Santa Clara River Valley, California

NASA Technical Reports Server (NTRS)

2000-01-01

Rectangular fields of the agriculturally rich Santa Clara River Valley are visible in this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image. The Santa Clara River, which lends its name to this valley, flows from headwaters near Acton, California, 160 km (100 miles) to the Pacific Ocean, and is one of only two natural river systems remaining in southern California. In the foreground of this image, the largely dry riverbed can be seen as a bright feature as it winds its way along the base of South Mountain. The bright region at the right end of this portion of the valley is the city of Santa Paula, California. Founded in 1902, this small, picturesque town at the geographic center of Ventura County is referred to as the 'Citrus Capital of the World.' The city is surrounded by orange, lemon, and avocado groves and is a major distribution point for citrus fruits in the United States. The bright, linear feature in the center of the valley is State Highway 126, the valley's 'main drag.' For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory

Morphodynamic Evolution of Yangtze (Changjiang) Estuary in Decadal-timescale: Alteration from Natural Processes to Human Interferences

NASA Astrophysics Data System (ADS)

Luan, H.; Ding, P.; Ge, J.; Zong, H.; Zheng Bing, W.

2016-02-01

Morphodynamic development of river deltas has attracted intensive attention in the past several decades due to ecological and economic significance. Present study quantified the morphological evolution processes of the Yangtze Estuary in decadal-timescale (1958-2010) aiming at understanding the effects of natural processes (river inputs) on the estuary and its morphological responses to human interferences. Inner Estuary (IE) and Mouth Bar Area (MBA) underwent substantially different changes in the study period. The net accretion rate of IE was 36.2 mm/yr in 1958-1978 and -70.9 mm/yr in 1986-1997, indicating that the IE altered from deposition to erosion along with the decline of river sediment input. By contrast, the MBA showed sustained accretion throughout the study period. The results suggested that the IE is more sensitive to the river sediment reduction than the MBA. The river flood may induce erosion in IE which can explain the erosion peak in 1986-1997 since there are continuous flood years in 1990s. The majority of erosion within IE in 1986-1997 occurred in South Branch. The depocenter within MBA transferred between the North Channel and the South Passage. Specifically, the depocenter was in the South Passage during 1958-1978, in the North Channel during 1978-1986, and back to the South Passage during 1986-1997. This is thought to be caused by the change in sediment diversion between the South and North Channel, except 1986-1997. Highest accretion rate (48.9mm/yr) in 1997-2010 is found within the North Passage if excluding the effects of navigation channel dredging. Previous research has quantified the morphological changes along the North Passage and attributed high deposition to the construction of dikes and perpendicular groins. The fluvial-marine transition in terms of prevailing forcing and sediment property is the natural characteristics of river deltas and play an essential role on morphological development of Yangtze Estuary. Present evidence shows

Identification and apportionment of hazardous elements in the sediments in the Yangtze River estuary.

PubMed

Wang, Jiawei; Liu, Ruimin; Wang, Haotian; Yu, Wenwen; Xu, Fei; Shen, Zhenyao

2015-12-01

In this study, positive matrix factorization (PMF) and principal components analysis (PCA) were combined to identify and apportion pollution-based sources of hazardous elements in the surface sediments in the Yangtze River estuary (YRE). Source identification analysis indicated that PC1, including Al, Fe, Mn, Cr, Ni, As, Cu, and Zn, can be defined as a sewage component; PC2, including Pb and Sb, can be considered as an atmospheric deposition component; and PC3, containing Cd and Hg, can be considered as an agricultural nonpoint component. To better identify the sources and quantitatively apportion the concentrations to their sources, eight sources were identified with PMF: agricultural/industrial sewage mixed (18.6 %), mining wastewater (15.9 %), agricultural fertilizer (14.5 %), atmospheric deposition (12.8 %), agricultural nonpoint (10.6 %), industrial wastewater (9.8 %), marine activity (9.0 %), and nickel plating industry (8.8 %). Overall, the hazardous element content seems to be more connected to anthropogenic activity instead of natural sources. The PCA results laid the foundation for the PMF analysis by providing a general classification of sources. PMF resolves more factors with a higher explained variance than PCA; PMF provided both the internal analysis and the quantitative analysis. The combination of the two methods can provide more reasonable and reliable results.

Approximation and spatial regionalization of rainfall erosivity based on sparse data in a mountainous catchment of the Yangtze River in Central China.

PubMed

Schönbrodt-Stitt, Sarah; Bosch, Anna; Behrens, Thorsten; Hartmann, Heike; Shi, Xuezheng; Scholten, Thomas

2013-10-01

In densely populated countries like China, clean water is one of the most challenging issues of prospective politics and environmental planning. Water pollution and eutrophication by excessive input of nitrogen and phosphorous from nonpoint sources is mostly linked to soil erosion from agricultural land. In order to prevent such water pollution by diffuse matter fluxes, knowledge about the extent of soil loss and the spatial distribution of hot spots of soil erosion is essential. In remote areas such as the mountainous regions of the upper and middle reaches of the Yangtze River, rainfall data are scarce. Since rainfall erosivity is one of the key factors in soil erosion modeling, e.g., expressed as R factor in the Revised Universal Soil Loss Equation model, a methodology is needed to spatially determine rainfall erosivity. Our study aims at the approximation and spatial regionalization of rainfall erosivity from sparse data in the large (3,200 km(2)) and strongly mountainous catchment of the Xiangxi River, a first order tributary to the Yangtze River close to the Three Gorges Dam. As data on rainfall were only obtainable in daily records for one climate station in the central part of the catchment and five stations in its surrounding area, we approximated rainfall erosivity as R factors using regression analysis combined with elevation bands derived from a digital elevation model. The mean annual R factor (R a) amounts for approximately 5,222 MJ mm ha(-1) h(-1) a(-1). With increasing altitudes, R a rises up to maximum 7,547 MJ mm ha(-1) h(-1) a(-1) at an altitude of 3,078 m a.s.l. At the outlet of the Xiangxi catchment erosivity is at minimum with approximate R a=1,986 MJ mm ha(-1) h(-1) a(-1). The comparison of our results with R factors from high-resolution measurements at comparable study sites close to the Xiangxi catchment shows good consistance and allows us to calculate grid-based R a as input for a spatially high-resolution and area-specific assessment of

Boundary of the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

USGS Publications Warehouse

Rupert, Michael G.; Plummer, Niel

2009-01-01

This vector data set delineates the approximate boundary of the Eagle River watershed valley-fill aquifer (ERWVFA). This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. The boundary of the ERWVFA was developed by combining information from two data sources. The first data source was a 1:250,000-scale geologic map of the Leadville quadrangle developed by Day and others (1999). The location of Quaternary sediments was used as a first approximation of the ERWVFA. The boundary of the ERWVFA was further refined by overlaying the geologic map with Digital Raster Graphic (DRG) scanned images of 1:24,000 topographic maps (U.S. Geological Survey, 2001). Where appropriate, the boundary of the ERWVFA was remapped to correspond with the edge of the valley-fill aquifer marked by an abrupt change in topography at the edge of the valley floor throughout the Eagle River watershed. The boundary of the ERWVFA more closely resembles a hydrogeomorphic region presented by Rupert (2003, p. 8) because it is based upon general geographic extents of geologic materials and not on an actual aquifer location as would be determined through a rigorous hydrogeologic investigation.

Effects of ground-water withdrawals on flow in the Sauk River Valley Aquifer and on streamflow in the Cold Spring area, Minnesota

USGS Publications Warehouse

Lindgren, R.J.

2001-01-01

The simulated contributing areas for selected watersupply wells in the Cold Spring area generally extend to and possibly beyond the model boundaries to the north and to the southeast. The contributing areas for the Gold'n Plump Poultry Processing Plant supply wells extend: (1) to the Sauk River, (2) to the north to and possibly beyond to the northern model boundary, and (3) to the southeast to and possibly beyond the southeastern model boundary. The primary effects of projected increased ground-water withdrawals of 0.23 cubic feet per second (7.5 percent increase) were to: (1) decrease outflow from the Sauk River Valley aquifer through constant-head boundaries and (2) decrease leakage from the valley unit of the Sauk River Valley aquifer to the streams. No appreciable differences were discernible between the simulated steady-state contributing areas to wells with 1998 pumpage and those with the projected pumpage.

A subsynoptic-scale kinetic energy study of the Red River Valley tornado outbreak (AVE-SESAME 1)

NASA Technical Reports Server (NTRS)

Jedlovec, G. J.; Fuelberg, H. E.

1981-01-01

The subsynoptis-scale kinetic energy balance during the Red River Valley tornado outbreak is presented in order to diagnose storm environment interactions. Area-time averaged energetics indicate that horizontal flux convergence provides the major energy source to the region, while cross contour flow provides the greatest sink. Maximum energy variability is found in the upper levels in association with jet stream activity. Area averaged energetics at individual observation times show that the energy balance near times of maximum storm activity differs considerably from that of the remaining periods. The local kinetic energy balance over Oklahoma during the formation of a limited jet streak receives special attention. Cross contour production of energy is the dominant local source for jet development. Intense convection producing the Red River Valley tornadoes may have contributed to this local development by modifying the surrounding environment.

Potential utility of tree ring δ18O series for reconstructing precipitation records from the lower reaches of the Yangtze River, southeast China

NASA Astrophysics Data System (ADS)

Xu, Chenxi; Ge, Junyi; Nakatsuka, Takeshi; Yi, Liang; Zheng, Huaizhou; Sano, Masaki

2016-04-01

In this study, we investigated the interannual and intraannual variabilities in the oxygen isotope composition (δ18O) preserved in the tree ring cellulose of Pinus taiwanensis in the lower reaches of the Yangtze River, southeast China, to explore its potential utility for precipitation reconstruction over the period of 1855-2013. Intraannual variations of tree ring cellulose δ18O show distinct annual cycles that are characterized by δ18O maxima in the early growth near the ring boundary and δ18O minima in the middle and late portions of the ring. Seasonal patterns of tree ring δ18O were influenced by August-October typhoons. The tree ring cellulose δ18O was measured in both young and old trees to test for the juvenile effect. The results revealed no significant differences in the mean values and long-term trends in δ18O in the old and young trees. A response analysis indicated that tree ring δ18O correlated significantly with precipitation and relative humidity between May and October, and the δ18O chronology accounted for 37.4% of the actual variation in the May-October precipitation between 1951 and 2013. The extremely dry and wet years revealed by the tree ring δ18O-based reconstructed precipitation also corresponded to actual local drought and flood events from the documentary records. Reconstructed precipitation showed significant relationship with central tropical Pacific sea surface temperature, which indicated that El Niño-Southern Oscillation (ENSO) exerted influences on May-October precipitation in the lower reaches of the Yangtze River. In addition, the relationship between ENSO and precipitation weakened between 1920 and 1940, and low variance of ENSO from 1920 to 1940 may result in the damped ENSO's influences on precipitation in southeast China.

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

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

Dong, Xinyi; Li, Juan; Fu, Joshua S.

2014-05-15

China announced the Chinese National Ambient Air Quality standards (CH-NAAQS) on Feb. 29th, 2012, and PM2.5 is for the very first time included in the standards as a criteria pollutant. In order to probe into PM2.5 pollution over Yangtze River Delta, which is one of the major urban clusters hosting more than 80 million people in China, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Both simulation and observation demonstrated that, inorganic aerosols have substantial contributions to PM2.5 overmore » YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3-) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3-concentration throughout the year. We also found that in winter NO3- was even increased under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4+) and sulfate (SO42-), while other seasons showed decrease response of NO3-. Sensitivity responses of NO3- under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3- formation was actually VOC sensitive due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols.« less

Use Of limestone resources in flue-gas desulfurization power plants in the Ohio River Valley

USGS Publications Warehouse

Foose, M.P.; Barsotti, A.F.

1999-01-01

In 1994, more than 41 of the approximately 160 coal-fired, electrical- power plants within the six-state Ohio River Valley region used flue-gas desulfurization (FGD) units to desulfurize their emissions, an approximately 100% increase over the number of plants using FGD units in 1989. This increase represents a trend that may continue with greater efforts to meet Federal Clean Air Act standards. Abundant limestone resources exist in the Ohio River Valley and are accessed by approximately 975 quarries. However, only 35 of these are believed to have supplied limestone for FGD electrical generating facilities. The locations of these limestone suppliers do not show a simple spatial correlation with FGD facilities, and the closest quarries are not being used in most cases. Thus, reduction in transportation costs may be possible in some cases. Most waste generated by FGD electrical-generating plants is not recycled. However, many FGD sites are relatively close to gypsum wallboard producers that may be able to process some of their waste.

Fuel regulation in inland navigation: Reduced soil black carbon deposition in river valleys in Germany

NASA Astrophysics Data System (ADS)

Bläsing, M.; Shao, Y.; Lehndorff, E.

2015-11-01

Inland navigation is of increasing economic and ecological interest, however its contribution to environmental quality is hardly known. We hypothesized that i) inland navigation emits considerable amounts of soot-Black Carbon (BC) as a product of incomplete combustion of diesel fuel, which is then deposited on soils along river valleys, that ii) improvement of fuel quality by sulfur reduction in 2011 decreased BC inputs to soil, and that iii) this provides a tracer for the spatial impact of inland navigation emissions. The spatial and temporal patterns of soil BC deposits from inland navigation were investigated yearly (2010-2013) working within transects perpendicular to the rivers Rhine, Moselle and Ahr, Germany (the Ahr Valley is free of shipping and served as a reference). In rural areas at inland waterways navigation likely represented the dominant BC emitter. Topsoils (0-10 cm depth) were sampled in vineyards. Their BC content and composition was determined via oxidation of bulk soil organic matter to benzene polycarboxylic acids (BPCAs). The highly trafficked Rhine Valley yielded only little more BC (64.7 ± 12 g BC kg-1 soil organic carbon (SOC) compared to 51.7 ± 9 at the Moselle, and 53.6 ± 6 at the reference Ahr Valley). At both inland waterways soil BC increased towards the river, following the simulated dispersal of ship-derived BC using a Lagrangian model. In the course of ship fuel regulation, soil BC deposits at the Rhine and Moselle waterways decreased significantly from 70.2 ± 3.2 to 47.9 ± 1.1 and 57.6 ± 1.3 to 41.7 ± 0.9 g BC kg-1 SOC within 3 years. Even more pronounced was the change in BC composition, i.e., the ratio of pentacarboxylated to mellitic acid increased from 0.75 to 1.3 (Rhine) and 1 to 1.4 (Moselle) during this time span. From this we calculated that ∼30% less BC was deposited by inland navigation likely due to reduced BC emissions after sulfur regulation in ship diesel.

Long-term accumulation and transport of anthropogenic phosphorus in three river basins

NASA Astrophysics Data System (ADS)

Powers, Stephen M.; Bruulsema, Thomas W.; Burt, Tim P.; Chan, Neng Iong; Elser, James J.; Haygarth, Philip M.; Howden, Nicholas J. K.; Jarvie, Helen P.; Lyu, Yang; Peterson, Heidi M.; Sharpley, Andrew N.; Shen, Jianbo; Worrall, Fred; Zhang, Fusuo

2016-05-01

Global food production depends on phosphorus. Phosphorus is broadly applied as fertilizer, but excess phosphorus contributes to eutrophication of surface water bodies and coastal ecosystems. Here we present an analysis of phosphorus fluxes in three large river basins, including published data on fertilizer, harvested crops, sewage, food waste and river fluxes. Our analyses reveal that the magnitude of phosphorus accumulation has varied greatly over the past 30-70 years in mixed agricultural-urban landscapes of the Thames Basin, UK, the Yangtze Basin, China, and the rural Maumee Basin, USA. Fluxes of phosphorus in fertilizer, harvested crops, food waste and sewage dominate over the river fluxes. Since the late 1990s, net exports from the Thames and Maumee Basins have exceeded inputs, suggesting net mobilization of the phosphorus pool accumulated in earlier decades. In contrast, the Yangtze Basin has consistently accumulated phosphorus since 1980. Infrastructure modifications such as sewage treatment and dams may explain more recent declines in total phosphorus fluxes from the Thames and Yangtze Rivers. We conclude that human-dominated river basins may undergo a prolonged but finite accumulation phase when phosphorus inputs exceed agricultural demand, and this accumulated phosphorus may continue to mobilize long after inputs decline.

The diatraea complex (Lepidoptera: Crambidae) in Colombia’s Cauca River Valley: identity, distribution, and parasitoids

USDA-ARS?s Scientific Manuscript database

The sugarcane stem borers Diatraea saccharalis (Fabricius) and D. indigenella Dyar & Heinrich are common pests of sugarcane crops in Colombia’s Cauca river valley (CRV). In 2012, however, D. tabernella Dyar was recorded for the first time in northern CRV and just one year later D. busckella Dyar & H...

Simulation of future global warming scenarios in rice paddies with an open-field ecosystem warming facility

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) in Yangtze River Valley (YRV) suffered serious yield losses in 2003 when extreme heatwave (HW), hampered rice reproductive growth phase (RGP). Climate change induced extreme and asymmetrical fluctuations in temperature during heat sensitive stage of rice growth cycle, i.e., RG...

Siphateles (Gila) sp. and Catostomus sp. from the Pleistocene OIS-6 Lake Gale, Panamint Valley, Owens River system, California

NASA Astrophysics Data System (ADS)

Jayko, A. S.; Forester, R. M.; Smith, G. R.

2014-12-01

Panamint Valley lies within the Owens River system which linked southeastern Sierra Nevada basins between Mono Lake and Death Valley during glacial-pluvial times. Previous work indicates that late Pleistocene glacial-pluvial Lake Gale, Panamint Valley was an open system during OIS-6, a closed ground water supported shallow lake during OIS-4, and the terminal lake basin for the Owens River system during OIS-2. We here report the first occurrence of fossil fish from the Plio-Pleistocene Panamint basin. Fish remains are present in late Pleistocene OIS-6 nearshore deposits associated with a highstand that was spillway limited at Wingate Wash. The deposits contain small minnow-sized remains from both Siphateles or Gila sp. (chubs) and Catostomus sp. (suckers) from at least four locations widely dispersed in the basin. Siphateles or Gila sp. and Catostomus are indigenous to the Pleistocene and modern Owens River system, in particular to the historic Owens Lake area. Cyprinodon (pupfish) and Rhinichthys (dace) are known from the modern Amargosa River and from Plio-Pleistocene deposits in Death Valley to the east. The late Pleistocene OIS-6 to OIS-2 lacustrine and paleohydrologic record in Panamint basin is interpreted from ostracod assemblages, relative abundance of Artemia sp. pellets, shallow water indicators including tufa fragments, ruppia sp. fragments and the relative abundance of charophyte gyrogonites obtained from archived core, as well as faunal assemblages from paleoshoreline and nearshore deposits. The OIS-4 groundwater supported shallow saline lake had sufficiently low ratios of alkalinity to calcium (alk/Ca) to support the occurrence of exotic Elphidium sp. (?) foraminfera which are not observed in either OIS-2 or OIS-6 lacustrine deposits. The arrival of Owens River surface water into Panamint Basin during OIS-2 is recorded by the first appearance of the ostracod Limnocythere sappaensis at ~27 m depth in an ~100 m archived core (Smith and Pratt, 1957) which

Antibiotics in the surface water of the Yangtze Estuary: occurrence, distribution and risk assessment.

PubMed

Yan, Caixia; Yang, Yi; Zhou, Junliang; Liu, Min; Nie, Minghua; Shi, Hao; Gu, Lijun

2013-04-01

The occurrence and distribution of five groups of antibiotics were investigated in the surface water of Yangtze Estuary over four seasons. Of the 20 antibiotics, only sulfamerazine was not detected at all sampling sites, indicating widespread occurrence of antibiotic residues in the study area. Detection frequencies and concentrations of antibiotics were generally higher in January, indicating that low flow conditions and low temperature might enhance the persistence of antibiotics in water. Antibiotic levels varied with location, with the highest concentrations being observed around river discharge and sewage outfall. Furthermore, a positive correlation between total antibiotic and DOC concentrations revealed the significant role played by DOC. Risk assessment based on single compound exposure showed that sulfapyridine and sulfamethoxazole could cause medium risk to daphnid in the Yangtze Estuary. Copyright © 2012 Elsevier Ltd. All rights reserved.

Seismic local site effects characterization in the Andarax River Valley (SE Spain) from ambient seismic noise

NASA Astrophysics Data System (ADS)

Carmona, Enrique; García-Jerez, Antonio; Luzón, Francisco; Sánchez-Martos, Francisco; Sánchez-Sesma, Francisco J.; Piña, José

2014-05-01

This work is focused on the characterization of seismic local effects in the Low Andarax River Valley (SE Spain). The Low Andarax River valley is located in an active seismic region, with the higher seismic hazard values in Spain. The landform is composed mainly by sedimentary materials which increase its seismic hazard due to the amplification of the seismic inputs and spectral resonances. We study seismic local effects in the Low Andarax River by analyzing the Horizontal-to-Vertical Spectral Ratio (HVSR) of ambient noise records. The noise data were recorded during two field campaigns in 2012 and 2013. There have been a total of 374 noise measurements with 15 and 30 minutes duration. The acquisition was performed with a Digital Broadband Seismometer Guralp CMG-6TD. The distance between measurements was about 200 meters, covering an area around 40 km2. There have been 6 significant peak frequencies between 0.3 Hz and 5 Hz. It was possible to find interesting areas with similar spectral peaks that coincide with zones with similar microgravimetric anomalies at the alluvial valley. It is also observed a decrease in the frequency peaks from West to East suggesting increased sediment layer. We also compute the soil models at those sites where geotechnical information is available, assuming that the seismic noise is diffuse. We invert the HVSR for these places using horizontally layered models and in the imaginary part the Green functions at the source. It is observed that the S wave velocity inverted models are consistent with the known geotechnical information obtained from drilled boreholes. We identify the elastodynamic properties of the limestone-dolomite materials with a formation of phyllites and quartzite that form the basement of the depression, and those properties of the Miocene and Pliocene detrital deposits (marls, sandy silts, sands and conglomerates) that fill the valley. These results together with the observed resonant frequencies along the Andarax

Fish communities of the Sacramento River Basin: Implications for conservation of native fishes in the Central Valley, California

USGS Publications Warehouse

May, J.T.; Brown, L.R.

2002-01-01

The associations of resident fish communities with environmental variables and stream condition were evaluated at representative sites within the Sacramento River Basin, California between 1996 and 1998 using multivariate ordination techniques and by calculating six fish community metrics. In addition, the results of the current study were compared with recent studies in the San Joaquin River drainage to provide a wider perspective of the condition of resident fish communities in the Central Valley of California as a whole. Within the Sacramento drainage, species distributions were correlated with elevational and substrate size gradients; however, the elevation of a sampling site was correlated with a suite of water-quality and habitat variables that are indicative of land use effects on physiochemical stream parameters. Four fish community metrics - percentage of native fish, percentage of intolerant fish, number of tolerant species, and percentage of fish with external anomalies - were responsive to environmental quality. Comparisons between the current study and recent studies in the San Joaquin River drainage suggested that differences in water-management practices may have significant effects on native species fish community structure. Additionally, the results of the current study suggest that index of biotic integrity-type indices can be developed for the Sacramento River Basin and possibly the entire Central Valley, California. The protection of native fish communities in the Central Valley and other arid environments continues to be a conflict between human needs for water resources and the requirements of aquatic ecosystems; preservation of these ecosystems will require innovative management strategies.

Asian river fishes in the Anthropocene: threats and conservation challenges in an era of rapid environmental change.

PubMed

Dudgeon, D

2011-12-01

This review compares and contrasts the environmental changes that have influenced, or will influence, fishes and fisheries in the Yangtze and Mekong Rivers. These two rivers have been chosen because they differ markedly in the type and intensity of prevailing threats. The Mekong is relatively pristine, whereas the Three Gorges Dam on the Yangtze is the world's largest dam representing the apotheosis of environmental alteration of Asian rivers thus far. Moreover, it is situated at the foot of a planned cascade of at least 12 new dams on the upper Yangtze. Anthropogenic effects of dams and pollution of Yangtze fishes will be exacerbated by plans to divert water northwards along three transfer routes, in part to supplement the flow of the Yellow River. Adaptation to climate change will undoubtedly stimulate more dam construction and flow regulation, potentially causing perfect storm conditions for fishes in the Yangtze. China has already built dams along the upper course of the Mekong, and there are plans for as many as 11 mainstream dams in People's Democratic Republic (Laos) and Cambodia in the lower Mekong Basin. If built, they could have profound consequences for biodiversity, fisheries and human livelihoods, and such concerns have stalled dam construction. Potential effects of dams proposed for other rivers (such as Nujiang-Salween) are also cause for concern. Conservation or restoration measures to sustain some semblance of the rich fish biodiversity of Asian rivers can be identified, but their implementation may prove problematic in a context of increasing Anthropocene alteration of these ecosystems. © 2011 The Author. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Evaluating health of paddy rice field ecosystem with remote sensing and GIS in Lower Yangtze River Plain, China

NASA Astrophysics Data System (ADS)

Li, Jingjing; Qin, Zhihao; Li, Wenjuan; Lin, Lu

2008-10-01

A paddy rice ecosystem is a farming system composed of paddy, animals, microbes and other environmental factors in specific time and space, with particular temporal and spatial dynamics. Since paddy rice is a main grain crop to feed above half of population in China, the performance of paddy rice ecosystem is highly concerned to yield level of paddy and food supply safety in China. Therefore, monitoring the performance of paddy rice ecosystem is very important to obtain the required information for evaluation of ecosystem health. In the study we intend to develop an approach to monitor the ecosystem performance spatially and dynamically in a regional scale using MODIS remote sensing data and GIS spatial mapping. On the basis of key factors governing the paddy rice ecosystem, we accordingly develop the following three indicators for the evaluation: Crop growing index (CGI), environmental Index (EI), and pests-diseases index (PDI). Then, we integrated the three indicators into a model with different weight coefficients to calculate Comprehensive ecosystem health index (CEHI) to evaluate the performance and functioning of paddy rice ecosystem in a regional scale. CGI indicates the health status of paddy rice calculated from the normalizing enhanced vegetation Index (EVI) retrieved from MODIS data. EI is estimated from temperature Index (TI) and precipitation Index (PI) indicating heat and water stress on the rice field. PDI reflects the damage brought by pests and diseases, which can be estimated using the information obtained from governmental websites. Applying the approach to Lower Yangtze River Plain, we monitor and evaluate the performance of paddy rice ecosystem in various stages of rice growing period in 2006. The results indicated that the performance of the ecosystem was generally very encouraging. During booting stage and heading and blooming stage, the health level was the highest in Anhui province, which is the main paddy rice producer in the region

Assessment of the national schistosomiasis control program in a typical region along the Yangtze River, China.

PubMed

Hu, Yi; Li, Si; Xia, Congcong; Chen, Yue; Lynn, Henry; Zhang, Tiejun; Xiong, Chenglong; Chen, Gengxin; He, Zonggui; Zhang, Zhijie

2017-01-01

Schistosomiasis remains a major public health problem in eastern China, particularly along the Yangtze River Basin. The latest national schistosomiasis control program (NSCP) was implemented in 2005 with the main goal of reducing the rate of infection to less than 5% by 2008 and 1% by 2015. To assess the progress, we applied a Bayesian spatio-temporal model to describe dynamics of schistosomiasis in Guichi, Anhui Province, China, using annual parasitological and environmental data collected within 41 sample villages for the period 2005-2011. Predictive maps of schistosomiasis showed that the disease prevalence remains constant and low. Results of uncertainty analysis, in the form of probability contour maps (PCMs), indicated that the first goal of "infection rate less than 5% by 2008" was fully achieved in the study area. More longitudinal data for schistosomiasis are needed for the assessment of the second goal of "infection rate less than 1% by 2015". Compared with the traditional way of mapping uncertainty (e.g., variance or mean-square error), our PCMs provide more realistic information for schistosomiasis control. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Using drift nets to capture early life stages and monitor spawning of the yangtze river chinese sturgeon (Acipenser sinensis)

USGS Publications Warehouse

Wei, Q.W.; Kynard, B.; Yang, D.G.; Chen, X.H.; Du, H.; Shen, L.; Zhang, H.

2009-01-01

A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis, and monitor annual spawning success at Yichang on the Yangtze River, 1996-2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October-10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996-2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population. ?? 2009 Blackwell Verlag GmbH.

Combined effects of multiple large-scale hydraulic engineering on water stages in the middle Yangtze River

NASA Astrophysics Data System (ADS)

Han, Jianqiao; Sun, Zhaohua; Li, Yitian; Yang, Yunping

2017-12-01

Investigation of water stages influenced by human projects provides better understanding of riverine geomorphological processes and river management. Based on hydrological data collected over 60 years, an extreme stage-extreme discharge analysis and a specific-gauge analysis were performed to research the individual and combined effects of multiple engineering projects on a long-term time series of water stages in the middle Yangtze River. Conclusions are as follows. (1) In accordance with the operation years of the Jingjiang cutoff (CF), the Gezhouba Dam (GD), and the Three Gorges Dam (TGD), the time series (1955-2012) was divided into periods of P1 (1955-1970), P2 (1971-1980), P3 (1981-2002), and P4 (2003 - 2012). Water stage changes during P1-P2, P2-P3, and P3-P4 are varied because of the differences in the types and scales of these projects. The stage decreased at Shashi and increased at Luoshan owing to the operation of the CF. Additionally, after the GD was constructed, the low-flow stage decreased in the upstream reach of Chenglingji and increased in its downstream reach, whereas the flood stage merely decreased at Yichang. Moreover, the TGD resulted in an overall decrease in low-flow stages and a limited increase in flood stages because of the differential adjustments of river geometry and resistance between the low-flow channel and flood channel. (2) Although differences existed in the scouring mechanisms between streamwise erosion associated with dams and headward erosion associated with cutoffs, particular bed textures in the gravel reach led to a similar adjustment that stage reduction at Shashi was the greatest of all stations, which caused the flow slope and sediment transport capacity to decrease in the sandy reach. (3) These engineering projects caused changes in average low-flow and flood stages that varied between Yichang (- 1.58 and - 0.08 m respectively), Shashi (- 3.54 and - 0.12 m), and Luoshan (1.15 and 0.97 m) from P1 to P4. However, less

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

PubMed

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

2014-05-15

The new Chinese National Ambient Air Quality standards (CH-NAAQS) published on Feb. 29th, 2012 listed PM2.5 as criteria pollutant for the very first time. In order to probe into PM2.5 pollution over Yangtze River Delta, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Total PM2.5 concentration over YRD was found to have strong seasonal variation with higher values in winter months (up to 89.9 μg/m(3) in January) and lower values in summer months (down to 28.8 μg/m(3) in July). Inorganic aerosols were found to have substantial contribution to PM2.5 over YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3(-)) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3(-) concentration throughout the year. In winter, NO3(-) was found to increase under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4(+)) and sulfate (SO4(2-)), while other seasons showed decrease response of NO3(-). Sensitivity responses of NO3(-) under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3(-) formation was actually more sensitive to VOC than NOx due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols. Copyright © 2014 Elsevier B.V. All rights reserved.

Source Identification and Apportionment of Trace Elements in Soils in the Yangtze River Delta, China.

PubMed

Shao, Shuai; Hu, Bifeng; Fu, Zhiyi; Wang, Jiayu; Lou, Ge; Zhou, Yue; Jin, Bin; Li, Yan; Shi, Zhou

2018-06-12

Trace elements pollution has attracted a lot of attention worldwide. However, it is difficult to identify and apportion the sources of multiple element pollutants over large areas because of the considerable spatial complexity and variability in the distribution of trace elements in soil. In this study, we collected total of 2051 topsoil (0⁻20 cm) samples, and analyzed the general pollution status of soils from the Yangtze River Delta, Southeast China. We applied principal component analysis (PCA), a finite mixture distribution model (FMDM), and geostatistical tools to identify and quantitatively apportion the sources of seven kinds of trace elements (chromium (Cr), cadmium (Cd), mercury (Hg), copper (Cu), zinc (Zn), nickel (Ni), and arsenic (As)) in soil. The PCA results indicated that the trace elements in soil in the study area were mainly from natural, multi-pollutant and industrial sources. The FMDM also fitted three sub log-normal distributions. The results from the two models were quite similar: Cr, As, and Ni were mainly from natural sources caused by parent material weathering; Cd, Cu, and Zu were mainly from mixed sources, with a considerable portion from anthropogenic activities such as traffic pollutants, domestic garbage, and agricultural inputs, and Hg was mainly from industrial wastes and pollutants.

Evaluation of volatile organic compounds in two Mojave Desert basins-Mojave River and Antelope Valley-in San Bernardino, Los Angeles, and Kern Counties, California, June-October 2002

USGS Publications Warehouse

Densmore, Jill N.; Belitz, Kenneth; Wright, Michael T.; Dawson, Barbara J.; Johnson, Tyler D.

2005-01-01

The California Aquifer Susceptibility Assessment of the Ground-Water Ambient Monitoring and Assessment Program was developed to assess water quality and susceptibility of ground-water resources to contamination from surficial sources. This study focuses on the Mojave River and the Antelope Valley ground-water basins in southern California. Volatile organic compound (VOC) data were evaluated in conjunction with tritium data to determine a potential correlation with aquifer type, depth to top of perforations, and land use to VOC distribution and occurrence in the Mojave River and the Antelope Valley Basins. Detection frequencies for VOCs were compiled and compared to assess the distribution in each area. Explanatory variables were evaluated by comparing detection frequencies for VOCs and tritium and the number of compounds detected. Thirty-three wells were sampled in the Mojave River Basin (9 in the floodplain aquifer, 15 in the regional aquifer, and 9 in the sewered subset of the regional aquifer). Thirty-two wells were sampled in the Antelope Valley Basin. Quality-control samples also were collected to identify, quantify, and document bias and variability in the data. Results show that VOCs generally were detected slightly more often in the Antelope Valley Basin samples than in the Mojave River Basin samples. VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Tritium was detected more frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples, and it was detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Most of the samples collected in both basins for this study contained old water (water recharged prior to 1952). In general, in these desert basins, tritium need not be present for VOCs to be present. When VOCs were detected, young water (water recharge after 1952) was slightly more likely to be contaminated than old water

Emission Inventory Development and Application Based On an Atmospheric Emission Source Priority Control Classification Technology Method, a Case Study in the Middle Reaches of Yangtze River Urban Agglomerations, China

NASA Astrophysics Data System (ADS)

Sun, X.; Cheng, S.

2017-12-01