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Chenwuing Liu - One of the best experts on this subject based on the ideXlab platform.
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changes of groundwater level due to the 1999 chi chi earthquake in the choshui river Alluvial Fan in taiwan
Bulletin of the Seismological Society of America, 2004Co-Authors: Yeeping Chia, Yuanshian Wang, Jessie J Chiu, Chenwuing LiuAbstract:Changes of groundwater levels induced by the M L 7.3 Chi-Chi earthquake on 21 September 1999 were recorded at 157 out of 179 monitoring wells in the Choshui River Alluvial Fan. Of those, 67 observed large groundwater-level changes, ranging from 1.0 to 11.1 m. These 157 wells are clustered at 64 stations located approximately 2 to 50 km west of the north-south-trending Chelungpu fault. Both oscillatory and steplike changes of water level were observed on the analog records at the time of earthquake, while only steplike changes were observed on the hourly digital records. Coseismic changes of groundwater level were recorded not only in the confined aquifers but also in the partially confined aquifers and the unconfined aquifers. The recovery of water-level changes took minutes to months, depending primarily on hydrogeologic conditions of the confining layers. The sign and magnitude of coseismic water-level change at a well varied with its distance from the fault. The distribution of coseismic water-level changes induced by the Chi-Chi earthquake indicates that water-level rise predominated in most of the footwall area, whereas water-level fall prevailed in a narrow zone adjacent to the fault trace. Manuscript received 31 October 2000.
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geostatistical analysis and conditional simulation for estimating the spatial variability of hydraulic conductivity in the choushui river Alluvial Fan taiwan
Hydrological Processes, 2004Co-Authors: Chengshin Jang, Chenwuing LiuAbstract:This work evaluated the spatial variability and distribution of heterogeneous hydraulic conductivity (K) in the Choushui River Alluvial Fan in Taiwan, using ordinary kriging (OK) and mean and individual sequential Gaussian simulations (SGS). A baseline flow model constructed by upscaling parameters was inversely calibrated to determine the pumping and recharge rates. Simulated heads using different K realizations were then compared with historically measured heads. A global/local simulated error between simulated and measured heads was analysed to assess the different spatial variabilities of various estimated K distributions. The results of a MODFLOW simulation indicate that the OK realization had the smallest sum of absolute mean simulation errors (SAMSE) and the SGS realizations preserved the spatial variability of the measured K fields. Moreover, the SAMSE increases as the spatial variability of the K field increases. The OK realization yields small local simulation errors in the measured K field of moderate magnitude, whereas the SGS realizations have small local simulation errors in the measured K fields, with high and low values. The OK realization of K can be applied to perform a deterministic inverse calibration. The mean SGS method is suggested for constructing a K field when the application focuses on extreme values of estimated parameters and small calibration errors, such as in a simulation of contaminant transport in heterogeneous aquifers. The individual SGS realization is useful in stochastically assessing the spatial uncertainty of highly heterogeneous aquifers. Copyright 2004 John Wiley & Sons, Ltd.
Chengshin Jang - One of the best experts on this subject based on the ideXlab platform.
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primary sink and source of geogenic arsenic in sedimentary aquifers in the southern choushui river Alluvial Fan taiwan
Applied Geochemistry, 2010Co-Authors: Kuangliang Lu, Shengwei Wang, Chengshin Jang, Vivian Hsiuchuan Liao, Chungmin Liao, Fijohn ChangAbstract:Abstract This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River Alluvial Fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-Fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO 3 - and NH 4 + concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO 4 3 - and HCO 3 - along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.
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geostatistical analysis and conditional simulation for estimating the spatial variability of hydraulic conductivity in the choushui river Alluvial Fan taiwan
Hydrological Processes, 2004Co-Authors: Chengshin Jang, Chenwuing LiuAbstract:This work evaluated the spatial variability and distribution of heterogeneous hydraulic conductivity (K) in the Choushui River Alluvial Fan in Taiwan, using ordinary kriging (OK) and mean and individual sequential Gaussian simulations (SGS). A baseline flow model constructed by upscaling parameters was inversely calibrated to determine the pumping and recharge rates. Simulated heads using different K realizations were then compared with historically measured heads. A global/local simulated error between simulated and measured heads was analysed to assess the different spatial variabilities of various estimated K distributions. The results of a MODFLOW simulation indicate that the OK realization had the smallest sum of absolute mean simulation errors (SAMSE) and the SGS realizations preserved the spatial variability of the measured K fields. Moreover, the SAMSE increases as the spatial variability of the K field increases. The OK realization yields small local simulation errors in the measured K field of moderate magnitude, whereas the SGS realizations have small local simulation errors in the measured K fields, with high and low values. The OK realization of K can be applied to perform a deterministic inverse calibration. The mean SGS method is suggested for constructing a K field when the application focuses on extreme values of estimated parameters and small calibration errors, such as in a simulation of contaminant transport in heterogeneous aquifers. The individual SGS realization is useful in stochastically assessing the spatial uncertainty of highly heterogeneous aquifers. Copyright 2004 John Wiley & Sons, Ltd.
Changyuan Tang - One of the best experts on this subject based on the ideXlab platform.
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using major ions and stable isotopes to characterize recharge regime of a fault influenced aquifer in beiyishui river watershed north china plain
Journal of Hydrology, 2011Co-Authors: Shiqin Wang, Ruiqiang Yuan, Xianfang Song, Yinghua Zhang, Changyuan TangAbstract:A thorough understanding of recharge is usually a prerequisite for effective groundwater management. The recharge regime remains unrevealed in the piedmont plain of the North China Plain, where is considered as the main recharge zone of the Quaternary aquifer. To characterize the recharge regime, a case study is presented in the piedmont plain of the Beiyishui River Watershed. The piedmont plain consists of proluvial Fan and Alluvial Fan/plain, and groundwater quality in the two parts is distinct. Total dissolved solids and isotopic compositions are higher in the groundwater of proluvial Fan than the groundwater of the Alluvial Fan/plain. Local precipitation only recharges the groundwater in the proluvial Fan. Fracture water ascending along a buried normal fault and lateral inflow from the proluvial Fan feed the unconfined aquifer in the Alluvial Fan/plain. The runoff of the Beiyishui River seeps in the streambed of upper reaches and then overflows seasonally in middle reach. The recharge from middle reach to the aquifer is negligible. In addition, the fracture water originates from precipitation in the mountainous area with an average elevation about 500 m and discharges to the overlaying aquifer. The contribution of fracture water to the aquifer was estimated to be 77.9% in the Alluvial Fan/plain area. Due to the mixture in the aquifer, major ions leached from soil of the proluvial Fan are diluted and the hydrochemical pattern is changed from Ca Mg–HCO3 SO4 to Ca Mg–HCO3. It is considered that fracture water is the major recharge source of the unconfined aquifer and the variation of precipitation in mountainous area would primarily affect the recharge. This paper also shows the hydrological efficiency of buried normal fault as preferential flow.
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recharge source and hydrogeochemical evolution of shallow groundwater in a complex Alluvial Fan system southwest of north china plain
Environmental Earth Sciences, 2008Co-Authors: Guoying Pan, Changyuan Tang, Qiuying ZhangAbstract:Many cities around the world are developed at Alluvial Fans. With economic and industrial development and increase in population, quality and quantity of groundwater are often damaged by over-exploitation in these areas. In order to realistically assess these groundwater resources and their sustainability, it is vital to understand the recharge sources and hydrogeochemical evolution of groundwater in Alluvial Fans. In March 2006, groundwater and surface water were sampled for major element analysis and stable isotope (oxygen-18 and deuterium) compositions in Xinxiang, which is located at a complex Alluvial Fan system composed of a mountainous area, Taihang Mt. Alluvial Fan and Yellow River Alluvial Fan. In the Taihang mountainous area, the groundwater was recharged by precipitation and was characterized by Ca–HCO3 type water with depleted δ18O and δD (mean value of −8.8‰ δ18O). Along the flow path from the mountainous area to Taihang Mt. Alluvial Fan, the groundwater became geochemically complex (Ca–Na–Mg–HCO3–Cl–SO4 type), and heavier δ18O and δD were observed (around −8‰ δ18O). Before the surface water with mean δ18O of −8.7‰ recharged to groundwater, it underwent isotopic enrichment in Taihang Mt. Alluvial Fan. Chemical mixture and ion exchange are expected to be responsible for the chemical evolution of groundwater in Yellow River Alluvial Fan. Transferred water from the Yellow River is the main source of the groundwater in the Yellow River Alluvial Fan in the south of the study area, and stable isotopic compositions of the groundwater (mean value of −8.8‰ δ18O) were similar to those of transferred water (−8.9‰), increasing from the southern boundary of the study area to the distal end of the Fan. The groundwater underwent chemical evolution from Ca–HCO3, Na–HCO3, to Na–SO4. A conceptual model, integrating stiff diagrams, is used to describe the spatial variation of recharge sources, chemical evolution, and groundwater flow paths in the complex Alluvial Fan aquifer system.
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characteristics of chemistry and stable isotopes in groundwater of chaobai and yongding river basin north china plain
Hydrological Processes, 2008Co-Authors: Changyuan Tang, Xianfang Song, Akihiko Kondoh, Yasuo Sakura, Jingjie Yu, S KanekoAbstract:To identify the groundwater flow system in the North China Plain, the chemical and stable isotopes of the groundwater and surface water were analysed along the Chaobai River and Yongding River basin. According to the field survey, the study area in the North China Plain was classified hydrogeologically into three parts: mountain, Piedmont Alluvial Fan and lowland areas. The change of electrical conductance and pH values coincided with groundwater flow from mountain to lowland areas. The following groundwater types are recognized: Ca-HCO(3) and Ca-Mg-HCO(3) in mountain areas, Ca-Mg-HCO(3) and Na-K-HCO(3) in Piedmont Alluvial Fan areas, and HCO(3)-Na in lowland areas. The stable isotope distribution of groundwater in the study area also has a good corresponding relation with other chemical characteristics. Stable isotope signatures reveal a major recharge from precipitation and surface water in the mountain areas. Chemical and stable isotope analysis data suggest that mountain and Piedmont Alluvial Fan areas were the major recharge zones and the lowland areas belong to the main discharge zone. Precipitation and surface water were the major sources for groundwater in the North China Plain. Stable isotopic enrichment of groundwater near the dam area in front of the Piedmont Alluvial Fan areas shows that the dam water infiltrated to the ground after evaporation. As a result, from the stable isotope analysis, isotope value of groundwater tends to deplete from sea level (horizontal ground surface) to both top of the mountain and the bottom of the lowland areas in symmetrically. This suggests that groundwater in the study area is controlled by the altitude effect. Shallow groundwater in the study area belongs to the local flow system and deep groundwater part of the regional flow system. Copyright (C) 2007 John Wiley & Sons, Ltd.
Fijohn Chang - One of the best experts on this subject based on the ideXlab platform.
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primary sink and source of geogenic arsenic in sedimentary aquifers in the southern choushui river Alluvial Fan taiwan
Applied Geochemistry, 2010Co-Authors: Kuangliang Lu, Shengwei Wang, Chengshin Jang, Vivian Hsiuchuan Liao, Chungmin Liao, Fijohn ChangAbstract:Abstract This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River Alluvial Fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-Fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO 3 - and NH 4 + concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO 4 3 - and HCO 3 - along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.
Kimihito Nakamura - One of the best experts on this subject based on the ideXlab platform.
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multiple indicator study of groundwater flow and chemistry and the impacts of river and paddy water on groundwater in the Alluvial Fan of the tedori river japan
Hydrological Processes, 2016Co-Authors: Yumi Yoshioka, Kimihito Nakamura, Takanori Nakano, Haruhiko Horino, Kicheol Shin, Satoko Hashimoto, Shigeto KawashimaAbstract:To investigate the source, flow paths, and chemistry of rich resources of high-quality, shallow groundwater in the Alluvial Fan between the Tedori and Sai rivers in central Japan, we analysed stable isotope ratios of H, O, and Sr and concentrations of major dissolved ions and trace elements in groundwater, river water, and paddy water. The Sr-87/Sr-86 ratios of the groundwater are related to near-surface geology: groundwater in sediment from the Tedori River has high Sr-87/Sr-86 ratios (>0.711), whereas that from the Sai River in the north of the Fan has low Sr-87/Sr-86 ratios (<0.711). H-2 and O-18 values and Sr-87/Sr-86 ratios indicate that groundwater in the central and southern Fans is recharged by the Tedori River, whereas recharge in the north is from the Sai River. Mg2+, Ca2+, Sr2+, HCO3-, and SO42- concentrations and H-2 and O-18 values in the groundwater are high in the central Fan and, except for the northern area, tend to increase with distance from the Tedori River. There are linear relationships between Sr-87/Sr-86 ratio and the reciprocal concentrations of Sr2+, Mg2+, and Ca2+. These geochemical characteristics suggest that as groundwater recharged from the Tedori River flows towards the central Fan, it mixes with waters derived from precipitation and paddy water that have become enriched in these components during downward infiltration. These results are consistent with our hydrological analysis and numerical simulation of groundwater flow, thus verifying the validity of the model we used in our simulation of groundwater flow. Copyright (c) 2016 John Wiley & Sons, Ltd.
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assessment of long term changes in nitrogen pollution load potential from sewage treatment water in the tedori river Alluvial Fan area japan
Paddy and Water Environment, 2011Co-Authors: Toshisuke Maruyama, Fumikazu Noto, Kimihito Nakamura, Takeo Onishi, Hiroshi Takimoto, Masashi Yoshida, Shigeto KawasimaAbstract:Long-term changes (1974–2007) in the nitrogen pollution load potential (NPLP) arising from sewage treatment water were assessed in the Tedori River Alluvial Fan Area of Japan. The total NPLP from sewage treatment systems (STS) during the 34 year period was 439 t (103 kg) year−1 from about 260,000 users in 1974 increasing to a peak of 793 t year−1 in 1992 from about 363,000 users, and then decreasing to 676 t year−1 from about 400,000 users in 2007. The NPLP outflow into the area increased from 356 t year−1 in 1974 to a peak of 596 t year−1 in 1985 followed by a rapid decrease to 98 t year−1 in 2007. The NPLP outflow from the public STS to the Japan Sea began in 1979 and rapidly increased to 575 t year−1 in 2007 from about 362,000 users. This represents 85.5% of the total NPLP. The NPLP from septic tanks in the area was 356 t year−1 from about 107,000 users in 1974 gradually increasing to a peak of 587 t year−1 from about 177,000 users in 1985 before rapidly decreasing to 60 t year−1 from about 15,000 users in 2007. Although the current NPLP is about 98 t year−1 in the study area, the average NPLP during 34 years was very different at 424 t year−1. NPLP assessments affecting groundwater and closed water bodies should consider long-term processes of nitrogen pollution from STS over time periods compatible with the residence time of the receiving waters.
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assessment of environmental nitrogen pollution load potential from sewage treatment water in the tedori river Alluvial Fan area japan
Paddy and Water Environment, 2011Co-Authors: Toshisuke Maruyama, Fumikazu Noto, Tsuyoshi Takahashi, Kimihito Nakamura, Takeo OnishiAbstract:An evaluation of the nitrogen pollution load potential (NPLP) arising from several sewage treatment systems in the Tedori River Alluvial Fan Area was evaluated by determining the removal percentage of nitrogen as a result of sewage treatment and amounts of nitrogen lost from the different treatment systems. These data were applied to the entire area resulting in an estimated total NPLP of 734 t year−1 (103 kg year−1), of which 548 t year−1 discharges into the Japan Sea and so does not contribute to the pollution of the environment considered here. The residual 186 t year−1 of the NPLP has a high probability of causing groundwater or downstream pollution, with 58% of the NPLP being contributed from septic tanks not connected to public sewage systems. Rural sewage system accounted for about 18% of the NPLP. Material directly flowing into the middle stream of the Tedori River together with sewage water from small companies and untreated sewage water from local family dwellings made up about 3–12% of the NPLP. To improve water quality due to sewage effluent, it is essential to increase the number of connections to public sewage systems from septic tanks.