Water scarcity and pollution pose a threat to the sustainable development of cities and society.Therefore,it is crucial to analyze the hydrochemical characteristics and carbon dynamics of waterdeficient areas.Taking t...Water scarcity and pollution pose a threat to the sustainable development of cities and society.Therefore,it is crucial to analyze the hydrochemical characteristics and carbon dynamics of waterdeficient areas.Taking the Taiyuan section of Fenhe River as the research object,we systematically explored the hydrochemical characteristics of surface water and its evolutionary processes,as well as the ecological effect of algal carbonic anhydrase in carbon cycle using the hydrochemical evolution method and correlation analysis.The ternary diagram demonstrates that the main water chemical type in Fenhe River was SO^(2-)_(4)·Cl^(-)-Na^(+).The Gibbs and end-member diagrams of each ion display that the chemical composition of surface water was mainly controlled by silicate decomposition.The chemical ions originated mainly from dissolution of some minerals,such as plagioclase,halite,dolomite,calcite,and gypsum.The diatoms had a lower CO_(2)requirement because they exhibited a higher abundance at a lower partial pressure of CO_(2)(p CO_(2)).However,high CO_(2)concentration had a positive effect on cyanobacteria,which reduced the active transport of HCO_(3)^(-),saved the energy needed for this part of active transport,and indirectly improved the overall photosynthetic efficiency of algae.Carbonic anhydrase(CA)activity was significantly negatively correlated with p CO_(2)and positively correlated with HCO_(3)^(-)concentration,indicating that CA in water promoted the conversion of CO_(2)to HCO_(3)^(-).The HCO_(3)^(-)generated from this process continued to participate in the erosion of silicate rocks,sequestering CO_(2)in the form of Ca CO_(3),which has a non-negligible impact on the carbon sink in the Fenhe River.These consequences may have important implications for the biogeochemical cycling occurring in urban water.展开更多
Fouty-eight species of rare and endanged plants in the Fenhe Source,belong to 21 families 37 genera.There were 1specie of national second-class protected plant and 3 species of national third-class plants;4 species of...Fouty-eight species of rare and endanged plants in the Fenhe Source,belong to 21 families 37 genera.There were 1specie of national second-class protected plant and 3 species of national third-class plants;4 species of first-class protected plants,6 species of second-class protected plants and 14 species of third-class protected plants in Shanxi Province.On the basis of analyzing the endanged reasons,related protection countemeasures were put forward in this article.展开更多
In order to evaluate the need of controlling the temperature of water discharged from the Fenhe Reservoir, the reservoir water temperature distribution was examined. A three-dimensional mathematical model was used to ...In order to evaluate the need of controlling the temperature of water discharged from the Fenhe Reservoir, the reservoir water temperature distribution was examined. A three-dimensional mathematical model was used to simulate the in-plane and vertical distribution of water temperature. The parameters of the model were calibrated with field data of the temperature distribution in the Fenhe Reservoir. The simulated temperature of discharged water is consistent with the measured data. The difference in temperature between the discharged water and the natural river channel is less than 3 ℃ under the current operating conditions. This will not significantly impact the environment of downstream areas.展开更多
Tectonic movements and climate changes are two main controllers on the development of landform. In order to reconstruct the history of the evolution of the landform in the Fenhe drainage basin d...Tectonic movements and climate changes are two main controllers on the development of landform. In order to reconstruct the history of the evolution of the landform in the Fenhe drainage basin during middle-late Quaternary comprehensively, this paper has provided a variety of geomorphological and geologic evidences to discuss how tectonic movements and climate changes worked together to influence the landform processes. According to the features of the lacustrine and alluvial terraces in this drainage basin, it is deduced that it was the three tectonic uplifts that resulted in the three great lake-regressions with an extent of about 40-60 m and the formation of the three lacustrine terraces. The times when the tectonic uplifts took place are 0.76 MaBP, 0.55 MaBP and 0.13 MaBP respectively, synchronous with the formation of paleosol units S 8 , S 5 and S 1 respectively. During the intervals between two tectonic uplifts when tectonic movement was very weak, climate changes played a major role in the evolution of the paleolakes and caused frequent fluctuations of lake levels. The changes of the features of lacustrine sediment in the grabens show the extent of such fluctuations of lake level is about 2-3 m.展开更多
In this paper, we demonstrate the high resolution seismic reflection data for a depth range of several hundred meters across the Fenhe fault in Taiyuan city, China. In combination with the relevant borehole logs, thes...In this paper, we demonstrate the high resolution seismic reflection data for a depth range of several hundred meters across the Fenhe fault in Taiyuan city, China. In combination with the relevant borehole logs, these data provide useful constraints on the accurate position, geometry and deformation rate of the fault, as well as the kinematics of recent fault motion. The high resolution seismic reflection profiling revealed that the western branch of the Fenhe fault is a high angle, eastward dipping, oblique normal fault, and cutting up to the lower part of the Quaternary system. It was revealed that the top breaking point of this fault is at a depth of ～70m below the ground surface. A borehole log across the Fenhe fault permitted us to infer that there are two high angle, oppositely dipping, oblique normal faults. The eastem branch lies beneath the eastern embankment of the Fenhe river, dipping to the west and cutting into the Holocene late Pleistocene strata with a maximum vertical offset of ～8m. Another borehole log across the northern segment of the Fenhe fault indicates that the western branch of this fault has cut into the Holocene late Pleistocene strata with a maximum vertical offset of ～6m. The above mentioned data provide a minimum average Pleistocene Holocene vertical slip rate of 0 06～0 08mm/a and a maximum average large earthquake recurrence interval of 5 0～6 7ka for the Fenhe fault.展开更多
A robust tree-ring-width chronology was developed from two Pinus tabulaeformis sampling sites in the source of the Fenhe River,Shanxi Province,China.Based on the tree-ring-width indices,a 157-year long Palmer Drought ...A robust tree-ring-width chronology was developed from two Pinus tabulaeformis sampling sites in the source of the Fenhe River,Shanxi Province,China.Based on the tree-ring-width indices,a 157-year long Palmer Drought Severity Index(PDSI) was reconstructed,which explains 53.7% of the variance of the modeled PDSI over the common period 1957-2008.The drought periods in the study area include 1914-1931 and 1970 to the present,whereas the wet periods were 1866-1892 and 1932-1969.The drought of 1914-1931 was a severe long-lasting drought with a low inter-annual variability,and the drought of 1970-2009 was an overall long-term drought with a high inter-annual variability.The period of 1866-1892 is a continuously wet period with a low inter-annual variability and the period of 1932-1969 is an overall long-term wet period with a high inter-annual variability.The reconstructed PDSI series in the source of the Fenhe River shows synchronous variations with the regional drought/wetness indices.Spatial correlation analyses indicate that the higher correlations lie exclusively in the Fenhe River Basin.This indicates that the reconstructed PDSI has regional representativeness and can represent the drought history of the entire Fenhe River Basin to some extent.Furthermore,the reconstructed PDSI matches with the variability of the per unit yield of summer grain crops in Shanxi Province very well and they have significant correlation.From a long-term perspective the reconstructed PDSI series could supply scientific and valuable information to the water resources management and then help the sustainable development in agricultural production,economic development,and ecosystem balance.展开更多
Different from rivers in humid areas,the variability of riverine CO_(2) system in arid areas is heavily impacted by anthropogenic disturbance with the increasing urbanization and water withdrawals.In this study,the wa...Different from rivers in humid areas,the variability of riverine CO_(2) system in arid areas is heavily impacted by anthropogenic disturbance with the increasing urbanization and water withdrawals.In this study,the water chemistry and the controls of carbonate system in an urbanized river(the Fenhe River)on the semi-arid Loess Plateau were analyzed.The water chemistry of the river water showed that the high dissolved inorganic carbon(DIC)concentration(about 37 mg L^(-1))in the upstream with a karst land type was mainly sourced from carbonate weathering involved by H_(2)CO_(3) and H_(2)SO_(4),resulting in an oversaturated partial pressure of CO_(2)(pCO_(2))(about 800μatm).In comparison,damming resulted in the widespread appearance of non-free flowing river segments,and aquatic photosynthesis dominated the DIC and pCO_(2) spatiality demonstrated by the enriched stable isotope of DIC(δ^(13)CDIC).Especially in the mid-downstream flowing through major cities in warm and low-runoff August,some river segments even acted as an atmospheric CO_(2) sink.The noteworthy is wastewater input leading to a sudden increase in DIC(>55 mg L^(-1))and pCO_(2)(>4500μatm)in the downstream of Taiyuan City,and in cold November the increased DIC even extended to the outlet of the river.Our results highlight the effects of aquatic production induced by damming and urban sewage input on riverine CO_(2) system in semi-arid areas,and reducing sewage discharge may mitigate CO_(2) emission from the rivers.展开更多
基金Supported by the Fundamental Research Program of Shanxi Province(Nos.202103021223266,202203021211313,202303021211114,202303021222246)the Excellent Doctoral Research Project in Shanxi Province(No.QZX-2023005)the Shanxi Scientific and Technological Innovation Team of Halophiles Resources Utilization(No.202204051001035)。
文摘Water scarcity and pollution pose a threat to the sustainable development of cities and society.Therefore,it is crucial to analyze the hydrochemical characteristics and carbon dynamics of waterdeficient areas.Taking the Taiyuan section of Fenhe River as the research object,we systematically explored the hydrochemical characteristics of surface water and its evolutionary processes,as well as the ecological effect of algal carbonic anhydrase in carbon cycle using the hydrochemical evolution method and correlation analysis.The ternary diagram demonstrates that the main water chemical type in Fenhe River was SO^(2-)_(4)·Cl^(-)-Na^(+).The Gibbs and end-member diagrams of each ion display that the chemical composition of surface water was mainly controlled by silicate decomposition.The chemical ions originated mainly from dissolution of some minerals,such as plagioclase,halite,dolomite,calcite,and gypsum.The diatoms had a lower CO_(2)requirement because they exhibited a higher abundance at a lower partial pressure of CO_(2)(p CO_(2)).However,high CO_(2)concentration had a positive effect on cyanobacteria,which reduced the active transport of HCO_(3)^(-),saved the energy needed for this part of active transport,and indirectly improved the overall photosynthetic efficiency of algae.Carbonic anhydrase(CA)activity was significantly negatively correlated with p CO_(2)and positively correlated with HCO_(3)^(-)concentration,indicating that CA in water promoted the conversion of CO_(2)to HCO_(3)^(-).The HCO_(3)^(-)generated from this process continued to participate in the erosion of silicate rocks,sequestering CO_(2)in the form of Ca CO_(3),which has a non-negligible impact on the carbon sink in the Fenhe River.These consequences may have important implications for the biogeochemical cycling occurring in urban water.
基金Supported by Shanxi Natural Science Foundation(2006011095)~~
文摘Fouty-eight species of rare and endanged plants in the Fenhe Source,belong to 21 families 37 genera.There were 1specie of national second-class protected plant and 3 species of national third-class plants;4 species of first-class protected plants,6 species of second-class protected plants and 14 species of third-class protected plants in Shanxi Province.On the basis of analyzing the endanged reasons,related protection countemeasures were put forward in this article.
文摘In order to evaluate the need of controlling the temperature of water discharged from the Fenhe Reservoir, the reservoir water temperature distribution was examined. A three-dimensional mathematical model was used to simulate the in-plane and vertical distribution of water temperature. The parameters of the model were calibrated with field data of the temperature distribution in the Fenhe Reservoir. The simulated temperature of discharged water is consistent with the measured data. The difference in temperature between the discharged water and the natural river channel is less than 3 ℃ under the current operating conditions. This will not significantly impact the environment of downstream areas.
基金National Natural Science Foundation of China No.40071016
文摘Tectonic movements and climate changes are two main controllers on the development of landform. In order to reconstruct the history of the evolution of the landform in the Fenhe drainage basin during middle-late Quaternary comprehensively, this paper has provided a variety of geomorphological and geologic evidences to discuss how tectonic movements and climate changes worked together to influence the landform processes. According to the features of the lacustrine and alluvial terraces in this drainage basin, it is deduced that it was the three tectonic uplifts that resulted in the three great lake-regressions with an extent of about 40-60 m and the formation of the three lacustrine terraces. The times when the tectonic uplifts took place are 0.76 MaBP, 0.55 MaBP and 0.13 MaBP respectively, synchronous with the formation of paleosol units S 8 , S 5 and S 1 respectively. During the intervals between two tectonic uplifts when tectonic movement was very weak, climate changes played a major role in the evolution of the paleolakes and caused frequent fluctuations of lake levels. The changes of the features of lacustrine sediment in the grabens show the extent of such fluctuations of lake level is about 2-3 m.
文摘In this paper, we demonstrate the high resolution seismic reflection data for a depth range of several hundred meters across the Fenhe fault in Taiyuan city, China. In combination with the relevant borehole logs, these data provide useful constraints on the accurate position, geometry and deformation rate of the fault, as well as the kinematics of recent fault motion. The high resolution seismic reflection profiling revealed that the western branch of the Fenhe fault is a high angle, eastward dipping, oblique normal fault, and cutting up to the lower part of the Quaternary system. It was revealed that the top breaking point of this fault is at a depth of ～70m below the ground surface. A borehole log across the Fenhe fault permitted us to infer that there are two high angle, oppositely dipping, oblique normal faults. The eastem branch lies beneath the eastern embankment of the Fenhe river, dipping to the west and cutting into the Holocene late Pleistocene strata with a maximum vertical offset of ～8m. Another borehole log across the northern segment of the Fenhe fault indicates that the western branch of this fault has cut into the Holocene late Pleistocene strata with a maximum vertical offset of ～6m. The above mentioned data provide a minimum average Pleistocene Holocene vertical slip rate of 0 06～0 08mm/a and a maximum average large earthquake recurrence interval of 5 0～6 7ka for the Fenhe fault.
基金supported by National Natural Science Foundation of China (Grant Nos. 40901060,41023006,and 40890051)National Basic Research Program of China (Grant No. 2010CB833405)the State Key Laboratory of Loess and Quaternary Geology and the Sino-Swedish Tree-Ring Research Center (SISTRR) Contribution
文摘A robust tree-ring-width chronology was developed from two Pinus tabulaeformis sampling sites in the source of the Fenhe River,Shanxi Province,China.Based on the tree-ring-width indices,a 157-year long Palmer Drought Severity Index(PDSI) was reconstructed,which explains 53.7% of the variance of the modeled PDSI over the common period 1957-2008.The drought periods in the study area include 1914-1931 and 1970 to the present,whereas the wet periods were 1866-1892 and 1932-1969.The drought of 1914-1931 was a severe long-lasting drought with a low inter-annual variability,and the drought of 1970-2009 was an overall long-term drought with a high inter-annual variability.The period of 1866-1892 is a continuously wet period with a low inter-annual variability and the period of 1932-1969 is an overall long-term wet period with a high inter-annual variability.The reconstructed PDSI series in the source of the Fenhe River shows synchronous variations with the regional drought/wetness indices.Spatial correlation analyses indicate that the higher correlations lie exclusively in the Fenhe River Basin.This indicates that the reconstructed PDSI has regional representativeness and can represent the drought history of the entire Fenhe River Basin to some extent.Furthermore,the reconstructed PDSI matches with the variability of the per unit yield of summer grain crops in Shanxi Province very well and they have significant correlation.From a long-term perspective the reconstructed PDSI series could supply scientific and valuable information to the water resources management and then help the sustainable development in agricultural production,economic development,and ecosystem balance.
基金supported by the National Natural Science Foundation of China (NSFC) (No.41376123)the Youth Project of Shanxi Basic Research (Nos.20210302124317,201901D211383)+1 种基金the Research and Promotion Project of Water Conservancy Science and Technology in Shanxi Province (No.2023GM41)the Science and Technology Innovation Fund of Shanxi Agricultural University (No.2018YJ21)。
文摘Different from rivers in humid areas,the variability of riverine CO_(2) system in arid areas is heavily impacted by anthropogenic disturbance with the increasing urbanization and water withdrawals.In this study,the water chemistry and the controls of carbonate system in an urbanized river(the Fenhe River)on the semi-arid Loess Plateau were analyzed.The water chemistry of the river water showed that the high dissolved inorganic carbon(DIC)concentration(about 37 mg L^(-1))in the upstream with a karst land type was mainly sourced from carbonate weathering involved by H_(2)CO_(3) and H_(2)SO_(4),resulting in an oversaturated partial pressure of CO_(2)(pCO_(2))(about 800μatm).In comparison,damming resulted in the widespread appearance of non-free flowing river segments,and aquatic photosynthesis dominated the DIC and pCO_(2) spatiality demonstrated by the enriched stable isotope of DIC(δ^(13)CDIC).Especially in the mid-downstream flowing through major cities in warm and low-runoff August,some river segments even acted as an atmospheric CO_(2) sink.The noteworthy is wastewater input leading to a sudden increase in DIC(>55 mg L^(-1))and pCO_(2)(>4500μatm)in the downstream of Taiyuan City,and in cold November the increased DIC even extended to the outlet of the river.Our results highlight the effects of aquatic production induced by damming and urban sewage input on riverine CO_(2) system in semi-arid areas,and reducing sewage discharge may mitigate CO_(2) emission from the rivers.
