This study firstly analyzed the shrinkage of winter wheat and the changes of crop- ping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, inclu...This study firstly analyzed the shrinkage of winter wheat and the changes of crop- ping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calcu- lated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1） The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×10^4 ha. The shrinkage was most serious in the Bei- jing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2） The precipitation fill rate of winter wheat was only 20%-30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 ram. 3） The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×10^8 m^3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.展开更多
Ground fissure hazards frequently emerge in Hebei Plain, which damage roads, dams, buildings and farmland. The paper reviews and analyses current state of knowledge and research into ground fissure and geological envi...Ground fissure hazards frequently emerge in Hebei Plain, which damage roads, dams, buildings and farmland. The paper reviews and analyses current state of knowledge and research into ground fissure and geological environment in Hebei Plain. It is shown that the level of research and investigation is in some aspects insufficient. Knowledge is lacking in the use of corresponding geological concept models for specific ground fissures, three-dimensional numerical simulations of ground fissures caused by pumping through soil with pre-existing fractures, numerical simulations of ground fissures caused by dislocation in intersection faults, and the failure criterion and the constitutive relationship of rock and soil. Furthermore, we put forward geological concept models for ground fissure formation following the dislocation of a buried intersection fault, over-exploitation of groundwater and its compound origin mechanisms in order to provide scientific evidence for the quantitative analysis.展开更多
It becomes an increasing concern that groundwater quality in exploited deep confined aquifer may deteriorate due to brackish water leakage from its overlying saline aquifer in Hebei Plain. However, the monitoring data...It becomes an increasing concern that groundwater quality in exploited deep confined aquifer may deteriorate due to brackish water leakage from its overlying saline aquifer in Hebei Plain. However, the monitoring data show that the TDS does not significantly change in the exploited aquifer. Some physics or chemistry processes must have taken place in aquitards during brackish leakage. The semi-permeable membrane function of clay aquitard during the process of hyperfiltration（reverse osmosis） should be one of the most important processes. To confirm and test this hyperfiltration mechanism, a series of experiments were performed in which Na Cl solutions were hydraulically forced through different clay sampled from aquitard. The solution 7 g/L in NaC l was forced through at 20 °C by a fluid pressure of 0.5 kN. The results show that hyperfiltration indeed happens in caly aquitard. Semi-permeability is quantified by the reflection coefficient σ. The mean rejection coefficients（σ） for clay samples #1, #2 and #3 were estimated to be 0.063, 0.164 and 0.040, respectively. This behavior of clay was well explained with the theory of the diffuse double layer. The hyperfiltration effect is to the great extent responsible for the chemical process in the aquitard.展开更多
Variation of terrestrial water storage in the Hebei plain area from March 2010 to June 2014 was studied using ground gravimetry combined with vertical displacement data from the Global Navigation Satellite System.Resu...Variation of terrestrial water storage in the Hebei plain area from March 2010 to June 2014 was studied using ground gravimetry combined with vertical displacement data from the Global Navigation Satellite System.Results show that observed gravity variation in this area increased continuously,basically reflecting a trend toward land subsidence.With the effect of this subsidence removed,a dominantnegative change in gravity variation was evident,reflecting an average rate of decrease in terrestrial water in this area of 0.10±0.053 m/y,and this is equivalent to a volume of 81.5±43.2×108 m^(3)and is consistent with the spatial distribution of groundwater change from measured hydrologic data.These results can be an essential reference and supplement for the study of terrestrial water variation in the Hebei plain area,and indicate that ground surface gravimetry can be used as an important mean for studying changes in terrestrial water.展开更多
Accurate estimation of groundwater recharge is essential for efficient and sustainable groundwater management in many semi-arid regions. In this paper, a lumped parameter model（EARTH） was established to simulate the...Accurate estimation of groundwater recharge is essential for efficient and sustainable groundwater management in many semi-arid regions. In this paper, a lumped parameter model（EARTH） was established to simulate the recharge rate and recharge process in typical areas by the observation datum of weather, soil water and groundwater synthetically, and the spatial and temporal variation law of groundwater recharge in the Hebei Plain was revealed. The mean annual recharge rates at LQ, LC, HS, DZ and CZ representative zones are 220.1, 196.7, 34.1, 141.0 and 188.0 mm/a and the recharge coefficients are 26.5%, 22.3%, 7.2%, 20.4%, and 22.0%, respectively. Recharge rate and recharge coefficient are gradually reduced from piedmont plain to coastal plain. Groundwater recharge appears as only yearly waves, with higher frequency components of the input series filtered by the deep complicated unsaturated zone（such as LC）. While at other zones, groundwater recharge series strongly dependent on the daily rainfall and irrigation because of the shallow water table or coarse lithology.展开更多
Based on short period Rayleigh wave data recorded by Beliing Seismic Telemetered Network, the dispersion curves of Raleigh wave phase velocity, with period from 2 s to 1 8 s, are calculated by means of two-station met...Based on short period Rayleigh wave data recorded by Beliing Seismic Telemetered Network, the dispersion curves of Raleigh wave phase velocity, with period from 2 s to 1 8 s, are calculated by means of two-station method, for 5 paths across the earthquake zone located in the Beijing graben and the Hebei plain. According to the dispersion features, the upper and middle crustal S wave velocity structures are respectively obtained for the northern segment of Beijing graben and the northern part of Hebei plain. The results show that there is an obvious interface at the depth of g kin in the Beijing graben, the velocity varies little with depth in the middle crust, and there is a low-velocity-zone, with a thickness of 5 km and a buried depth of 14.6 km, in the middle crust of the Hebei plain.展开更多
Based on three typical mediums(sandy loam, loam and sandy clay loam) in Hebei Plain, this paper designs phreatic evaporation experiments under different lithology and phreatic depth. Based on the analysis of experimen...Based on three typical mediums(sandy loam, loam and sandy clay loam) in Hebei Plain, this paper designs phreatic evaporation experiments under different lithology and phreatic depth. Based on the analysis of experimental data, the phreatic evaporation law and influencing factors of three mediums were studied. The results showed that:(1) The shallower the phreatic depth, the larger the phreatic evaporation.(2) Sandy clay loam has the biggest response to the increase of the phreatic depth, sandy loam is the second and loam is the smallest.(3) The limit depth of phreatic evaporation of sandy clay loam is about 3 m and that of loam and sandy loam is about 2 m and 3 m, seperately.(4) By fitting the daily evaporation of phreatic water and phreatic depth, the results showed that sandy loam and sandy clay loam are exponential functions and loam is power functions.展开更多
In order to study the distribution and evolution features of saline soil, the correlations between the groundwater depth, salinity and salinization of soil are examined through analyzing the hydrometeorological data a...In order to study the distribution and evolution features of saline soil, the correlations between the groundwater depth, salinity and salinization of soil are examined through analyzing the hydrometeorological data and distribution maps of saline soil, groundwater depth and salinity in 1957 and 2005. The results show that the area of salinization has generally decreased. The area of salinization decreases with the increasing groundwater depth, and the dynamic evolution characteristics appeared between the groundwater depth and area of salinization. The area of heavy salinization is greatest when the groundwater salinity is > 5 g/L, the area of moderate salinization is greatest when the groundwater salinity is between 2-5 g/L, the area of light salinization is greatest when the groundwater salinity is 1-2 g/L and the area of non-salinization is greatest when the groundwater salinity is <1 g/L. The area of heavy salinization was characterized with groundwater depth <2.5 m and salinity >1.8 g/L. The area of non-salinization was characterized with groundwater depth >4.0 m and salinity 0.2-1.5 g/L.展开更多
Groundwater is the main water source in the Hebei Plain. Evolution of groundwater chemistry can not only provide scientific data for sustainable usage of groundwater resources, but also help us in better understanding...Groundwater is the main water source in the Hebei Plain. Evolution of groundwater chemistry can not only provide scientific data for sustainable usage of groundwater resources, but also help us in better understanding hydrogeochemical processes in aquifers. Spatial distribution and temporal evolution were analyzed on basis of monitoring data between 1975 and 2005. Results showed that major components in groundwater had increasing trends since 1970s. Major components in shallow groundwater increased more than those in deep one. In shallow groundwater of piedmont alluvial fan-recharge zone, concentrations of Na＋, Ca2＋, SO42- had great increasing trends, while other major components increased by less than 30%. There were great increasing trends in Na＋, Cl-, SO42- concentrations in deep groundwater of central alluvial plain-intermediate zone, while other major components increased by no more than 20%. Deep groundwater from coast plain-discharge zone and piedmont alluvial fan-recharge zone showed no significant variations in major ion concentrations. In shallow groundwater, dissolution, evaporation and human activities played a major role in the increase in major components. However, groundwater mixture resulting from deep groundwater exploitation was believed to be the major factors for the increases in major components in deep groundwater of central alluvial plain-intermediate zone.展开更多
Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have develope...Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have developed,of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui,Hebei Province,with a total length of 3 km,a dominant strike of NE78°,and nearly upright in the shallow layer.The surface damage observed in this fissure primarily manifests as beaded pits,and its activity shows distinct segmentation characteristics.On the trench profiles,the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to-3 m.An evident flexure is observed in the strata at depths ranging from-4.5 to-7 m.The drilling profile reveals that there is an absence of dislocations in the deeper strata.Nonetheless,the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area,underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure.Firstly,the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults.The interplay of the regional stress field,fault block movement,and fault activity played pivotal roles in driving the development of this paleochannel.Secondly,the paleochannel exerts a controlling influence on the development location and severity of the fissure.During pumping,the confined aquifer within the paleochannel undergoes water loss and compression,resulting in the formation of a surface subsidence funnel.When the tensile stress surpasses the soil's tensile strength at the funnel's edge,the soil fractures give rise to a ground fissure.Finally,large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture,emerge,and expand.This paper provides a heretofore generally unknown example,promotes research on the mechanisms of paleochannel-controlled fissures,and has guiding significance for disaster prevention and reduction in this area.展开更多
To analyze the genesis of Sr isotopes in groundwater of Hebei plain, time-accumulative effect of ^87Sr/^86Sr ratio was studied. It is shown that ^87Sr/^86Sr ratio increases with the increasing age and depth of groundw...To analyze the genesis of Sr isotopes in groundwater of Hebei plain, time-accumulative effect of ^87Sr/^86Sr ratio was studied. It is shown that ^87Sr/^86Sr ratio increases with the increasing age and depth of groundwater and has a positive correlation to 4Heexc and a negative correlation to δ^18O and δD.The groundwater is divided into three groups to discuss the relation between ^87Sr/^86Sr ratio and Sr^2＋ content： ① moderate Sr^2＋ content and higher ^87Sr/^86Sr ratio （water Ⅰ）; ② lower Sr^2＋ content and higher ^87Sr/^86Sr ratio （water Ⅱ）; and ③ higher Sr^2＋ content and lower ^87Sr/^86Sr ratio （water Ⅲ）, that is hot water. On the basis of integrated analysis, it was considered that ① the radiogenic Sr in the Quaternary groundwater （Q4-Q1） originates from weathering of silicate rich in Na and Rb, mainly from plagioclase; ② the radiogenic Sr of hot water in Huanghua port is attributed to carbonate dissolution, with lower ^87Sr/^86Sr ratio and higher Sr/Na ratio; ③ the recharge area is laterally recharged by the groundwater flowing through igneous and metamorphic rocks, with moderate ^87Sr/^86Sr ratio. However, the formation mechanism of Sr isotopes in Tertiary groundwater needs further studies.展开更多
Based on the monthly and annual rainfall data of 1955―2000,the multi-time scales characteristics of seasonal and annual rainfall in the past 45 years in the Hebei Plain have been analyzed using Mexican Hat wavelet an...Based on the monthly and annual rainfall data of 1955―2000,the multi-time scales characteristics of seasonal and annual rainfall in the past 45 years in the Hebei Plain have been analyzed using Mexican Hat wavelet analysis in this article.The periodic oscillation of rainfall variation and the points of abrupt change at different time scales along the time series are dis-covered.According to the main periods,the trend of rainfall variation in the future has also been estimated.The results indicate that there are obvious periodic oscillations of 8―12 years and 4―6 years for the seasonal and annual rainfalls variation.The variation trend of the summer rainfall is in agreement with that of the annual rainfall and both of them have the main periods of 1 year and 12 years.It is estimated,based on the main period of 1 year,that the amount of rainfall will be relatively small around 2003 and abundant around 2004―2007 in the Hebei Plain.展开更多
Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological we...Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological wet fronts were different. The sandy loam had the fastest migration rate, the loam followed, and the clay loam was the slowest, but the law of change is the same among the three lithologies. The volumetric water content affects the change of Boltzmann parameter λ. When the volumetric water content is between 0.35-0.45 cm^3/cm^3,λ approaches stability. When the volumetric water content is less than 0.35 cm^3/cm^3, the λ value decreases rapidly with the decrease of water content. The water diffusion rate is related to the volumetric water content and particle size. The greater the moisture content is, the greater the diffusion rate will be. The larger the particle size, the larger the diffusion rate. The diffusivity of sandy loam is 10-30 times larger than that of loam and clay loam. The relationship between water content and diffusion rate is in accordance with the exponential function .展开更多
Chlorine-36 has various advantages as a dating tool for old groundwater. In this paper, 36CI of Quaternary groundwater in the Hebei plain of North China has been measured using accelerator mass spectrometry (AMS). Age...Chlorine-36 has various advantages as a dating tool for old groundwater. In this paper, 36CI of Quaternary groundwater in the Hebei plain of North China has been measured using accelerator mass spectrometry (AMS). Ages calculated from the 36CI/CI ratio show that ion filtration, which is responsible for the CI- concentration increasing with depth and along flow paths in Hebei plain groundwater. It is concluded that 36CI age of the groundwater in the 3rd Group of the Quaternary (Q2) in the Cangzhou area is 250ka, and that of the 4th Group(Q1) is 300ka.展开更多
The study on 82 surface soil pollen samples from different types of cultivated vegetations in central and southern parts of Hebei Province indicates that the pollen assem- blages from farmlands in the plain have not o...The study on 82 surface soil pollen samples from different types of cultivated vegetations in central and southern parts of Hebei Province indicates that the pollen assem- blages from farmlands in the plain have not only their own plant types, but also the pollen components from the nearby mountains. Arboreal pollen percentages and concentrations （dominated by Pinus） from farmlands in mountain area are higher than those in the plain, and it reduces gradually with the increasing distance away from the mountains. Taking Pinus pollen in Taihang Mountains as an example, its content is 20%-30%, 10%-20%, 20%-30% and below 16% respectively for the samples from the area of 0-50, 50-100, 100-150 and more than 150 km away from the east Taihang Mountains. The increase of Pinus pollen proportion in the central plain is probably related to the fohn effect. The spatial variation of AP from mountains to the plain in Hebei Province may be similar to the forests clearance by human activities in the early historical period. Shrubby pollen proportion is small both in mountains and in the plain, but their major components are different. Elaeagnaceae, Corylus, Ostryopsis and Oleaceae are common in mountain areas, while there are relatively high contents of Rosaceae and Vitaceae in the plain. Herbs content in the plain （about 60%） is 15% higher than that in mountains, among which the Cereals and Cruciferae pollen percentages are 5% and 2% higher respectively. Artemisia pollen percentage in the plain is lower than that in mountains. Since the human activities are weaker in mountains compared with that in the plain, the general trend is that Chenopodiaceae pollen increases from mountains to the plain gradually, reflecting the raising intensity of human activities. The fern spores of Selaginella sinensis in mountains are higher than that in the plain, but it still reaches to about 7% in the plain. The fern spores of Selaginella sinensis are not prone to be spread by wind, indicating that those in the surface soil of the plain may be carried by river water from mountains during the deposition of the plain.展开更多
基金National Natural Science Foundation of China,No.41101085
文摘This study firstly analyzed the shrinkage of winter wheat and the changes of crop- ping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calcu- lated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1） The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×10^4 ha. The shrinkage was most serious in the Bei- jing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2） The precipitation fill rate of winter wheat was only 20%-30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 ram. 3） The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×10^8 m^3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.
基金supported by 973 ProgramSpecial Item(2010CB428805-1)the National Natural Science Foundation Project(41102138)
文摘Ground fissure hazards frequently emerge in Hebei Plain, which damage roads, dams, buildings and farmland. The paper reviews and analyses current state of knowledge and research into ground fissure and geological environment in Hebei Plain. It is shown that the level of research and investigation is in some aspects insufficient. Knowledge is lacking in the use of corresponding geological concept models for specific ground fissures, three-dimensional numerical simulations of ground fissures caused by pumping through soil with pre-existing fractures, numerical simulations of ground fissures caused by dislocation in intersection faults, and the failure criterion and the constitutive relationship of rock and soil. Furthermore, we put forward geological concept models for ground fissure formation following the dislocation of a buried intersection fault, over-exploitation of groundwater and its compound origin mechanisms in order to provide scientific evidence for the quantitative analysis.
基金financially supported by the National Basic Research Program of China (No. 2010CB428803)the National Natural Science Foundation of China (Nos. 41272252, 41472225)
文摘It becomes an increasing concern that groundwater quality in exploited deep confined aquifer may deteriorate due to brackish water leakage from its overlying saline aquifer in Hebei Plain. However, the monitoring data show that the TDS does not significantly change in the exploited aquifer. Some physics or chemistry processes must have taken place in aquitards during brackish leakage. The semi-permeable membrane function of clay aquitard during the process of hyperfiltration（reverse osmosis） should be one of the most important processes. To confirm and test this hyperfiltration mechanism, a series of experiments were performed in which Na Cl solutions were hydraulically forced through different clay sampled from aquitard. The solution 7 g/L in NaC l was forced through at 20 °C by a fluid pressure of 0.5 kN. The results show that hyperfiltration indeed happens in caly aquitard. Semi-permeability is quantified by the reflection coefficient σ. The mean rejection coefficients（σ） for clay samples #1, #2 and #3 were estimated to be 0.063, 0.164 and 0.040, respectively. This behavior of clay was well explained with the theory of the diffuse double layer. The hyperfiltration effect is to the great extent responsible for the chemical process in the aquitard.
基金supported by the Director Foundation of Institute of Seismology,China Earthquake Administration(Grant Nos:IS201726121)the National Natural Science Foundation of China(Grant Nos:41304059)the special earthquake research grant offered by China Earthquake Administration(Grant Nos:201308009,201508009)。
文摘Variation of terrestrial water storage in the Hebei plain area from March 2010 to June 2014 was studied using ground gravimetry combined with vertical displacement data from the Global Navigation Satellite System.Results show that observed gravity variation in this area increased continuously,basically reflecting a trend toward land subsidence.With the effect of this subsidence removed,a dominantnegative change in gravity variation was evident,reflecting an average rate of decrease in terrestrial water in this area of 0.10±0.053 m/y,and this is equivalent to a volume of 81.5±43.2×108 m^(3)and is consistent with the spatial distribution of groundwater change from measured hydrologic data.These results can be an essential reference and supplement for the study of terrestrial water variation in the Hebei plain area,and indicate that ground surface gravimetry can be used as an important mean for studying changes in terrestrial water.
基金the financial support by the 973 Program of China (No. 2010CB428802)the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (No. CUGL120217)the China Geological Survey (No. 200310400035.1)
文摘Accurate estimation of groundwater recharge is essential for efficient and sustainable groundwater management in many semi-arid regions. In this paper, a lumped parameter model（EARTH） was established to simulate the recharge rate and recharge process in typical areas by the observation datum of weather, soil water and groundwater synthetically, and the spatial and temporal variation law of groundwater recharge in the Hebei Plain was revealed. The mean annual recharge rates at LQ, LC, HS, DZ and CZ representative zones are 220.1, 196.7, 34.1, 141.0 and 188.0 mm/a and the recharge coefficients are 26.5%, 22.3%, 7.2%, 20.4%, and 22.0%, respectively. Recharge rate and recharge coefficient are gradually reduced from piedmont plain to coastal plain. Groundwater recharge appears as only yearly waves, with higher frequency components of the input series filtered by the deep complicated unsaturated zone（such as LC）. While at other zones, groundwater recharge series strongly dependent on the daily rainfall and irrigation because of the shallow water table or coarse lithology.
文摘Based on short period Rayleigh wave data recorded by Beliing Seismic Telemetered Network, the dispersion curves of Raleigh wave phase velocity, with period from 2 s to 1 8 s, are calculated by means of two-station method, for 5 paths across the earthquake zone located in the Beijing graben and the Hebei plain. According to the dispersion features, the upper and middle crustal S wave velocity structures are respectively obtained for the northern segment of Beijing graben and the northern part of Hebei plain. The results show that there is an obvious interface at the depth of g kin in the Beijing graben, the velocity varies little with depth in the middle crust, and there is a low-velocity-zone, with a thickness of 5 km and a buried depth of 14.6 km, in the middle crust of the Hebei plain.
基金supported by the basic research fund of the GAGS(YYWF201624)Hebei graduate's innovative funding(CXZZSS20181)
文摘Based on three typical mediums(sandy loam, loam and sandy clay loam) in Hebei Plain, this paper designs phreatic evaporation experiments under different lithology and phreatic depth. Based on the analysis of experimental data, the phreatic evaporation law and influencing factors of three mediums were studied. The results showed that:(1) The shallower the phreatic depth, the larger the phreatic evaporation.(2) Sandy clay loam has the biggest response to the increase of the phreatic depth, sandy loam is the second and loam is the smallest.(3) The limit depth of phreatic evaporation of sandy clay loam is about 3 m and that of loam and sandy loam is about 2 m and 3 m, seperately.(4) By fitting the daily evaporation of phreatic water and phreatic depth, the results showed that sandy loam and sandy clay loam are exponential functions and loam is power functions.
基金funded by 973 Program Special Item (2010CB428805-1)
文摘In order to study the distribution and evolution features of saline soil, the correlations between the groundwater depth, salinity and salinization of soil are examined through analyzing the hydrometeorological data and distribution maps of saline soil, groundwater depth and salinity in 1957 and 2005. The results show that the area of salinization has generally decreased. The area of salinization decreases with the increasing groundwater depth, and the dynamic evolution characteristics appeared between the groundwater depth and area of salinization. The area of heavy salinization is greatest when the groundwater salinity is > 5 g/L, the area of moderate salinization is greatest when the groundwater salinity is between 2-5 g/L, the area of light salinization is greatest when the groundwater salinity is 1-2 g/L and the area of non-salinization is greatest when the groundwater salinity is <1 g/L. The area of heavy salinization was characterized with groundwater depth <2.5 m and salinity >1.8 g/L. The area of non-salinization was characterized with groundwater depth >4.0 m and salinity 0.2-1.5 g/L.
基金financially supported by the National Basic Research Program of China (No. 2010CB428804)the Geological Survey Program of China Geological Survey (No. 12120113103700)
文摘Groundwater is the main water source in the Hebei Plain. Evolution of groundwater chemistry can not only provide scientific data for sustainable usage of groundwater resources, but also help us in better understanding hydrogeochemical processes in aquifers. Spatial distribution and temporal evolution were analyzed on basis of monitoring data between 1975 and 2005. Results showed that major components in groundwater had increasing trends since 1970s. Major components in shallow groundwater increased more than those in deep one. In shallow groundwater of piedmont alluvial fan-recharge zone, concentrations of Na＋, Ca2＋, SO42- had great increasing trends, while other major components increased by less than 30%. There were great increasing trends in Na＋, Cl-, SO42- concentrations in deep groundwater of central alluvial plain-intermediate zone, while other major components increased by no more than 20%. Deep groundwater from coast plain-discharge zone and piedmont alluvial fan-recharge zone showed no significant variations in major ion concentrations. In shallow groundwater, dissolution, evaporation and human activities played a major role in the increase in major components. However, groundwater mixture resulting from deep groundwater exploitation was believed to be the major factors for the increases in major components in deep groundwater of central alluvial plain-intermediate zone.
基金funded by the National Science Foundation of China(Nos.2022XAGG0400,42207202,42293351)the Open Fund of the Key Laboratory of Earth Fissures Geological Disaster,Ministry of Natural Resources,Geological Survey of Jiangsu Province,China(No.EFGD20240604)+2 种基金the Open Fund of the Observation and Research Station of Ground Fissure and Land Subsidence,Ministry of Natural Resources(No.GKF2024-06)the Fundamental Research Funds for the Central Universities of China University of Geosciences,Beijing(No.2-9-2021-014)the Fundamental Research Funds for the Central Universities of Chang'an University(No.300102264501-01)。
文摘Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have developed,of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui,Hebei Province,with a total length of 3 km,a dominant strike of NE78°,and nearly upright in the shallow layer.The surface damage observed in this fissure primarily manifests as beaded pits,and its activity shows distinct segmentation characteristics.On the trench profiles,the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to-3 m.An evident flexure is observed in the strata at depths ranging from-4.5 to-7 m.The drilling profile reveals that there is an absence of dislocations in the deeper strata.Nonetheless,the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area,underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure.Firstly,the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults.The interplay of the regional stress field,fault block movement,and fault activity played pivotal roles in driving the development of this paleochannel.Secondly,the paleochannel exerts a controlling influence on the development location and severity of the fissure.During pumping,the confined aquifer within the paleochannel undergoes water loss and compression,resulting in the formation of a surface subsidence funnel.When the tensile stress surpasses the soil's tensile strength at the funnel's edge,the soil fractures give rise to a ground fissure.Finally,large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture,emerge,and expand.This paper provides a heretofore generally unknown example,promotes research on the mechanisms of paleochannel-controlled fissures,and has guiding significance for disaster prevention and reduction in this area.
基金This paper is supported by China Geological Survey Project (No. 200320150002).
文摘To analyze the genesis of Sr isotopes in groundwater of Hebei plain, time-accumulative effect of ^87Sr/^86Sr ratio was studied. It is shown that ^87Sr/^86Sr ratio increases with the increasing age and depth of groundwater and has a positive correlation to 4Heexc and a negative correlation to δ^18O and δD.The groundwater is divided into three groups to discuss the relation between ^87Sr/^86Sr ratio and Sr^2＋ content： ① moderate Sr^2＋ content and higher ^87Sr/^86Sr ratio （water Ⅰ）; ② lower Sr^2＋ content and higher ^87Sr/^86Sr ratio （water Ⅱ）; and ③ higher Sr^2＋ content and lower ^87Sr/^86Sr ratio （water Ⅲ）, that is hot water. On the basis of integrated analysis, it was considered that ① the radiogenic Sr in the Quaternary groundwater （Q4-Q1） originates from weathering of silicate rich in Na and Rb, mainly from plagioclase; ② the radiogenic Sr of hot water in Huanghua port is attributed to carbonate dissolution, with lower ^87Sr/^86Sr ratio and higher Sr/Na ratio; ③ the recharge area is laterally recharged by the groundwater flowing through igneous and metamorphic rocks, with moderate ^87Sr/^86Sr ratio. However, the formation mechanism of Sr isotopes in Tertiary groundwater needs further studies.
基金This work was supported by the National Natural Science Foundation of China(Grant No.40335046).
文摘Based on the monthly and annual rainfall data of 1955―2000,the multi-time scales characteristics of seasonal and annual rainfall in the past 45 years in the Hebei Plain have been analyzed using Mexican Hat wavelet analysis in this article.The periodic oscillation of rainfall variation and the points of abrupt change at different time scales along the time series are dis-covered.According to the main periods,the trend of rainfall variation in the future has also been estimated.The results indicate that there are obvious periodic oscillations of 8―12 years and 4―6 years for the seasonal and annual rainfalls variation.The variation trend of the summer rainfall is in agreement with that of the annual rainfall and both of them have the main periods of 1 year and 12 years.It is estimated,based on the main period of 1 year,that the amount of rainfall will be relatively small around 2003 and abundant around 2004―2007 in the Hebei Plain.
基金financially supported by the Fundamental Research Fund of the Chinese Academy of Geological Sciences (YYFM201624)
文摘Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological wet fronts were different. The sandy loam had the fastest migration rate, the loam followed, and the clay loam was the slowest, but the law of change is the same among the three lithologies. The volumetric water content affects the change of Boltzmann parameter λ. When the volumetric water content is between 0.35-0.45 cm^3/cm^3,λ approaches stability. When the volumetric water content is less than 0.35 cm^3/cm^3, the λ value decreases rapidly with the decrease of water content. The water diffusion rate is related to the volumetric water content and particle size. The greater the moisture content is, the greater the diffusion rate will be. The larger the particle size, the larger the diffusion rate. The diffusivity of sandy loam is 10-30 times larger than that of loam and clay loam. The relationship between water content and diffusion rate is in accordance with the exponential function .
基金This project was supported by the National Natural Science Foundation of China (GrantNo.4917242) the Open Laboratory of Constitution, Interaction and Dynamics of the Crust-Mantle system. We thank Prof.Zhong Zengqiu for helpful comments.
文摘Chlorine-36 has various advantages as a dating tool for old groundwater. In this paper, 36CI of Quaternary groundwater in the Hebei plain of North China has been measured using accelerator mass spectrometry (AMS). Ages calculated from the 36CI/CI ratio show that ion filtration, which is responsible for the CI- concentration increasing with depth and along flow paths in Hebei plain groundwater. It is concluded that 36CI age of the groundwater in the 3rd Group of the Quaternary (Q2) in the Cangzhou area is 250ka, and that of the 4th Group(Q1) is 300ka.
基金Key National Natural Science Foundation of China, No.40730103 National Natural Science Foundation of China No. 40571166 and 40672107 Hebei Natural Science Foundation No.D2008000186, No.D2009000300
文摘The study on 82 surface soil pollen samples from different types of cultivated vegetations in central and southern parts of Hebei Province indicates that the pollen assem- blages from farmlands in the plain have not only their own plant types, but also the pollen components from the nearby mountains. Arboreal pollen percentages and concentrations （dominated by Pinus） from farmlands in mountain area are higher than those in the plain, and it reduces gradually with the increasing distance away from the mountains. Taking Pinus pollen in Taihang Mountains as an example, its content is 20%-30%, 10%-20%, 20%-30% and below 16% respectively for the samples from the area of 0-50, 50-100, 100-150 and more than 150 km away from the east Taihang Mountains. The increase of Pinus pollen proportion in the central plain is probably related to the fohn effect. The spatial variation of AP from mountains to the plain in Hebei Province may be similar to the forests clearance by human activities in the early historical period. Shrubby pollen proportion is small both in mountains and in the plain, but their major components are different. Elaeagnaceae, Corylus, Ostryopsis and Oleaceae are common in mountain areas, while there are relatively high contents of Rosaceae and Vitaceae in the plain. Herbs content in the plain （about 60%） is 15% higher than that in mountains, among which the Cereals and Cruciferae pollen percentages are 5% and 2% higher respectively. Artemisia pollen percentage in the plain is lower than that in mountains. Since the human activities are weaker in mountains compared with that in the plain, the general trend is that Chenopodiaceae pollen increases from mountains to the plain gradually, reflecting the raising intensity of human activities. The fern spores of Selaginella sinensis in mountains are higher than that in the plain, but it still reaches to about 7% in the plain. The fern spores of Selaginella sinensis are not prone to be spread by wind, indicating that those in the surface soil of the plain may be carried by river water from mountains during the deposition of the plain.
