Restoration and reconstruction of the degraded Tarim River ecosystem is an important challenge. A goal of an ecological water conveyance project is to protect and restore the natural vegetation in the lower reaches of...Restoration and reconstruction of the degraded Tarim River ecosystem is an important challenge. A goal of an ecological water conveyance project is to protect and restore the natural vegetation in the lower reaches of Tadm River by transferring water from Bosten Lake, through the river channel, to the lower reaches. This study describes the changes in groundwater depth during the water transfer and the respondence of riparian vegetation to alterations in groundwater levels. The results indicate that groundwater depth along the Tarim River channel has a significant spatial-temporal component. Groundwater levels closest to the river channel show the most immediate and pronounced changes as a response to water transfer while those further away respond more slowly, although the observed change appears to be longer in duration. With a rise in the groundwater level, natural vegetation responded with higher growth rates, biomass and biodiversity. These favorable changes show that it is feasible to protect and restore the degraded natural vegetation by raising the groundwater depth. Plant communities are likely to reflect the hysteresis phenomenon, requiting higher water levels to initiate and stimulate desired growth than what may be needed to maintain the plant community. Because different species have different ecologies, including different root depths and densities and water needs, their response to increasing water availability will be spatially and temporally heterogenous. The response of vegetation is also influenced by microtopography and watering style. This paper discusses strategies for the protection and restoration of the degraded vegetation in the lower reaches of the Tarim River and provides information to complement ongoing theoretical research into ecological restoration in add or semi-arid ecosystems.展开更多
Based on monitored data from 840 samples, we assessed the spatial and temporal variability of groundwater salinization in the Tarim River lower reaches combining classical statistics and geostatistics. Results show th...Based on monitored data from 840 samples, we assessed the spatial and temporal variability of groundwater salinization in the Tarim River lower reaches combining classical statistics and geostatistics. Results show that total dissolved solids (TDS) is significantly correlated with other related ions, such as Na+, Mg2+, Ca2-, C1- and K+. TDS and underground water level have characteristics of spatial autocorrelation, both of which present the isotropic characteristic and con- form to the spherical model in each year from 2001-2009. TDS is basically greater than 1 g/L but less than 2 g/L in the Tarim River lower reaches, which indicates that salt stagnation pollution is more serious. The most serious salinization (3 g/L 〈 TDS _〈 35 g/L) contaminated area is mainly in the middle and lower part of the study area.展开更多
The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwa...The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwater in the region of the middle and lower reaches of the YangtzeRiver and their relations to the composition of the water-bearing media, properties of the overly-ing rocks and soils, redox environment, and groundwater flow condition, mineralization and pHof groundwater.展开更多
The aim of this work is to evaluate the hydrogeochemical characteristics of groundwater in parts of the lower Benue Through in Nigeria as well as to evaluate the variation in groundwater chemistry data and the suitabi...The aim of this work is to evaluate the hydrogeochemical characteristics of groundwater in parts of the lower Benue Through in Nigeria as well as to evaluate the variation in groundwater chemistry data and the suitability of the groundwater for drinking and other domestic purposes.This was based on chemical analyses of 44 water samples from existing wells and boreholes in the study area.From the statistical analysis(wide ranges,median and standard deviation),it is obvious that there are significant variations in the quality/composition of groundwater in the period of sampling.The calculated SAR,Na% and RSC values indicated that the water is of excellent to good quality and is suitable for irrigation.Na and HCO3 are dominant with respect to the chemical composition of the groundwater.On the basis of water chemistry,hydrochemical indices and factor analysis the dominant controls or processes affecting the distribution of geochemical variables in the study area have been shown to be water/rock interaction which is mainly controlled by carbonate and silicate dissolution as well as anthropogenic influence to a lesser extent.Additional processes include cation exchange reactions and reverse ion exchange to a minor extent.展开更多
Investigating into the quality of groundwater in the lower Pra basin using physico-chemical parameters have been carried out. Samples were collected from thirty one (31) water points. All major ions were determined us...Investigating into the quality of groundwater in the lower Pra basin using physico-chemical parameters have been carried out. Samples were collected from thirty one (31) water points. All major ions were determined using standard methods. The results show that approximately 97% of the water sampled has TDS values less than 1000 mg/l. Chemical parameters are influenced primarily by silicate weathering, ion exchange processes and sea aerosol spray. Sodium ion (Na+) concentration is generally high compared to other cations and bicarbonate (HCO3-) is the most abundant anion. Approximately 90% of the samples have iron concentrations greater than the W.H.O. limit for drinking water. Aluminium showed relatively higher concentration than other trace metals. The maximum and minimum concentrations recorded for cadmium Cd are 0.005 mg/l and 0.013 mg/l respectively. Concentrations of lead (Pb) zinc (Zn) were below detection limit. The groundwater in the basin is generally Na-Cl in character. Minor water types such as Ca-Mg-HCO3, Na-Mg-Ca-HCO3 and Na-Cl-SO4 were also delineated.展开更多
Guided by the theory of groundwater system, based on the groundwater level data from the northern basin of Laiyuan Spring area, the authors took into account factors such as the lithology, geological structure and top...Guided by the theory of groundwater system, based on the groundwater level data from the northern basin of Laiyuan Spring area, the authors took into account factors such as the lithology, geological structure and topography to study the relationship between groundwater recharge, runoff and drainage in this area. It was concluded that the infiltration of atmospheric precipitation is the main source of groundwater supply in this area; the upper layer of the Spring area is distributed with the Cambrian-Lower Ordovician karst water, and the lower layer is filled with the Jixian system karst water. The upper layer of karst water supplies to the lower layer of karst water or the pore water in loose strata through the fault while the lower layer of karst water runs to the three strong runoff belts from the east and west sides of the watershed, southwards into the basin, partially replenishing the pore water in loose strata, or forming fault Springs(e.g. Nanguan Spring, Beihai Spring) when dolomite movement encounters faults. Replenished by atmospheric precipitation and the upper and lower layers of karst waters, the pore water in loose strata joins the groundwater in the southern basin and then flows eastwards, in the end it flows out of the system in Shangfanpu. Through the analyses of groundwater level data and hydrogeological drilling data, based on groundwater D and ^(18) O isotope test results, the karst groundwater circulation system in the northern basin of Laiyuan Spring area is further verified, which provides hydrogeological basis for water resources development and utilization as well as protection in this area.展开更多
A groundwater observational network for monitoring seismic precursors has been established at the reservoirs on the lower reaches of the Jinsha River in southwestern China, where a series of hydropower stations are un...A groundwater observational network for monitoring seismic precursors has been established at the reservoirs on the lower reaches of the Jinsha River in southwestern China, where a series of hydropower stations are under construction. It is the second network in China that is operated by enterprises with the purpose to observe and study earthquake precursors in reservoir areas. This paper presents the layout and technical constitution of the network, features of its observational wells and aquifers and the preliminary result of its experimental operation. Its capability to monitor seismic precursor is evaluated based on an analysis of the well-aquifer system as well as the multiple-monthly, monthly, daily and hourly variations of water levels and water temperatures observed by this network.展开更多
Remote sensing, one of the most important reconnaissance and feature identifying tools generally applied for surface and groundwater investigation, was used for water resources mapping for the lower Son Valley in this...Remote sensing, one of the most important reconnaissance and feature identifying tools generally applied for surface and groundwater investigation, was used for water resources mapping for the lower Son Valley in this study. The mapping was done with the help of Indian Remote Sensing (IRS) satellite imagery IRS-LISS- 1-B1 for January 29, 1991 obtained during the day transit time. The area under study comprises adjoining parts of Uttar Pradesh and Bihar states of India and extends over the seven districts, namely Bhojpur, Rohtas, Patna, Jahanabad, Aurangabad, Ballia and Chapra. Geology of the study area is quite complex, tectonically disturbed and shows four major cycles of depositions after erosions during last one billion years (since Cretaceous). Two lineaments mapped by GSI (Geological Survey of India) in western side of river Son in the Bhojpur district can also be identified by the satellite imagery. In the present study, apart from these lineaments, two new lineaments have been investigated, which run almost parallel to river Ganga in northwest parts of the area in Ballia district. The lineaments may play a very vital role in groundwater monitoring in the area. The detailed study of geomorphology, vegetation and geology of the Lower Son valley on the basis of photo-interpretation techniques for surface features, drainage pattern and density, and drainage texture has been carried out to determine alluvial type, permeability, tributary, etc. These studies and Darcy velocity analysis show that the prospect of water is very good for entire lower Son valley. The Bhojpur district is most prospective for groundwater exploitation.展开更多
This paper presents the studies on groundwater resources potential of the Yellow River (YR) terrace in Zhengzhou area, China. The main aim of the research was to resolve water shortage problems induced by recent but f...This paper presents the studies on groundwater resources potential of the Yellow River (YR) terrace in Zhengzhou area, China. The main aim of the research was to resolve water shortage problems induced by recent but frequent drying ups of the YR in its lower reaches. Geologic explorations and grouped-pumping tests were conducted in the area. Based on collected data a groundwater flow net was established. The buried depth of groundwater level and water bearing potential of the aquifers were evaluated. Conventional method was used to determine recharge of the groundwater by lateral infiltration of the YR in pumping patterns. The results show that the study region has a high water bearing potential and offers conditions for the construction of large water works. However, only limited recharge by lateral infiltration from the river is available when developing large scale groundwater exploitation in the riverside of the YR. Environmental impacts induced by embankment stability of the Great dyke of the YR could be minimized or eliminated by appropriate engineering methods.展开更多
基金Project supported by the National Natural Science Foundation of China (No.30470329,40671036,30600092)"Xibuzhiguang"Project of the Chinese Academy of Sciences (CAS).
文摘Restoration and reconstruction of the degraded Tarim River ecosystem is an important challenge. A goal of an ecological water conveyance project is to protect and restore the natural vegetation in the lower reaches of Tadm River by transferring water from Bosten Lake, through the river channel, to the lower reaches. This study describes the changes in groundwater depth during the water transfer and the respondence of riparian vegetation to alterations in groundwater levels. The results indicate that groundwater depth along the Tarim River channel has a significant spatial-temporal component. Groundwater levels closest to the river channel show the most immediate and pronounced changes as a response to water transfer while those further away respond more slowly, although the observed change appears to be longer in duration. With a rise in the groundwater level, natural vegetation responded with higher growth rates, biomass and biodiversity. These favorable changes show that it is feasible to protect and restore the degraded natural vegetation by raising the groundwater depth. Plant communities are likely to reflect the hysteresis phenomenon, requiting higher water levels to initiate and stimulate desired growth than what may be needed to maintain the plant community. Because different species have different ecologies, including different root depths and densities and water needs, their response to increasing water availability will be spatially and temporally heterogenous. The response of vegetation is also influenced by microtopography and watering style. This paper discusses strategies for the protection and restoration of the degraded vegetation in the lower reaches of the Tarim River and provides information to complement ongoing theoretical research into ecological restoration in add or semi-arid ecosystems.
基金supported by the National Basic Research Program of China(973 ProgramNo.2010CB951003)
文摘Based on monitored data from 840 samples, we assessed the spatial and temporal variability of groundwater salinization in the Tarim River lower reaches combining classical statistics and geostatistics. Results show that total dissolved solids (TDS) is significantly correlated with other related ions, such as Na+, Mg2+, Ca2-, C1- and K+. TDS and underground water level have characteristics of spatial autocorrelation, both of which present the isotropic characteristic and con- form to the spherical model in each year from 2001-2009. TDS is basically greater than 1 g/L but less than 2 g/L in the Tarim River lower reaches, which indicates that salt stagnation pollution is more serious. The most serious salinization (3 g/L 〈 TDS _〈 35 g/L) contaminated area is mainly in the middle and lower part of the study area.
文摘The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwater in the region of the middle and lower reaches of the YangtzeRiver and their relations to the composition of the water-bearing media, properties of the overly-ing rocks and soils, redox environment, and groundwater flow condition, mineralization and pHof groundwater.
文摘The aim of this work is to evaluate the hydrogeochemical characteristics of groundwater in parts of the lower Benue Through in Nigeria as well as to evaluate the variation in groundwater chemistry data and the suitability of the groundwater for drinking and other domestic purposes.This was based on chemical analyses of 44 water samples from existing wells and boreholes in the study area.From the statistical analysis(wide ranges,median and standard deviation),it is obvious that there are significant variations in the quality/composition of groundwater in the period of sampling.The calculated SAR,Na% and RSC values indicated that the water is of excellent to good quality and is suitable for irrigation.Na and HCO3 are dominant with respect to the chemical composition of the groundwater.On the basis of water chemistry,hydrochemical indices and factor analysis the dominant controls or processes affecting the distribution of geochemical variables in the study area have been shown to be water/rock interaction which is mainly controlled by carbonate and silicate dissolution as well as anthropogenic influence to a lesser extent.Additional processes include cation exchange reactions and reverse ion exchange to a minor extent.
文摘Investigating into the quality of groundwater in the lower Pra basin using physico-chemical parameters have been carried out. Samples were collected from thirty one (31) water points. All major ions were determined using standard methods. The results show that approximately 97% of the water sampled has TDS values less than 1000 mg/l. Chemical parameters are influenced primarily by silicate weathering, ion exchange processes and sea aerosol spray. Sodium ion (Na+) concentration is generally high compared to other cations and bicarbonate (HCO3-) is the most abundant anion. Approximately 90% of the samples have iron concentrations greater than the W.H.O. limit for drinking water. Aluminium showed relatively higher concentration than other trace metals. The maximum and minimum concentrations recorded for cadmium Cd are 0.005 mg/l and 0.013 mg/l respectively. Concentrations of lead (Pb) zinc (Zn) were below detection limit. The groundwater in the basin is generally Na-Cl in character. Minor water types such as Ca-Mg-HCO3, Na-Mg-Ca-HCO3 and Na-Cl-SO4 were also delineated.
基金supported by the geological survey project of China Geological Survey(CGS)“1:50000 Hydrogeological Surveys in Taihang Mountainous Area(9)”(No.12120114010801)
文摘Guided by the theory of groundwater system, based on the groundwater level data from the northern basin of Laiyuan Spring area, the authors took into account factors such as the lithology, geological structure and topography to study the relationship between groundwater recharge, runoff and drainage in this area. It was concluded that the infiltration of atmospheric precipitation is the main source of groundwater supply in this area; the upper layer of the Spring area is distributed with the Cambrian-Lower Ordovician karst water, and the lower layer is filled with the Jixian system karst water. The upper layer of karst water supplies to the lower layer of karst water or the pore water in loose strata through the fault while the lower layer of karst water runs to the three strong runoff belts from the east and west sides of the watershed, southwards into the basin, partially replenishing the pore water in loose strata, or forming fault Springs(e.g. Nanguan Spring, Beihai Spring) when dolomite movement encounters faults. Replenished by atmospheric precipitation and the upper and lower layers of karst waters, the pore water in loose strata joins the groundwater in the southern basin and then flows eastwards, in the end it flows out of the system in Shangfanpu. Through the analyses of groundwater level data and hydrogeological drilling data, based on groundwater D and ^(18) O isotope test results, the karst groundwater circulation system in the northern basin of Laiyuan Spring area is further verified, which provides hydrogeological basis for water resources development and utilization as well as protection in this area.
基金sponsored by the Jinsha River Development Corporation Ltd. Program of China Three Gorges Cooperation (JSJ(06)007)
文摘A groundwater observational network for monitoring seismic precursors has been established at the reservoirs on the lower reaches of the Jinsha River in southwestern China, where a series of hydropower stations are under construction. It is the second network in China that is operated by enterprises with the purpose to observe and study earthquake precursors in reservoir areas. This paper presents the layout and technical constitution of the network, features of its observational wells and aquifers and the preliminary result of its experimental operation. Its capability to monitor seismic precursor is evaluated based on an analysis of the well-aquifer system as well as the multiple-monthly, monthly, daily and hourly variations of water levels and water temperatures observed by this network.
文摘Remote sensing, one of the most important reconnaissance and feature identifying tools generally applied for surface and groundwater investigation, was used for water resources mapping for the lower Son Valley in this study. The mapping was done with the help of Indian Remote Sensing (IRS) satellite imagery IRS-LISS- 1-B1 for January 29, 1991 obtained during the day transit time. The area under study comprises adjoining parts of Uttar Pradesh and Bihar states of India and extends over the seven districts, namely Bhojpur, Rohtas, Patna, Jahanabad, Aurangabad, Ballia and Chapra. Geology of the study area is quite complex, tectonically disturbed and shows four major cycles of depositions after erosions during last one billion years (since Cretaceous). Two lineaments mapped by GSI (Geological Survey of India) in western side of river Son in the Bhojpur district can also be identified by the satellite imagery. In the present study, apart from these lineaments, two new lineaments have been investigated, which run almost parallel to river Ganga in northwest parts of the area in Ballia district. The lineaments may play a very vital role in groundwater monitoring in the area. The detailed study of geomorphology, vegetation and geology of the Lower Son valley on the basis of photo-interpretation techniques for surface features, drainage pattern and density, and drainage texture has been carried out to determine alluvial type, permeability, tributary, etc. These studies and Darcy velocity analysis show that the prospect of water is very good for entire lower Son valley. The Bhojpur district is most prospective for groundwater exploitation.
文摘This paper presents the studies on groundwater resources potential of the Yellow River (YR) terrace in Zhengzhou area, China. The main aim of the research was to resolve water shortage problems induced by recent but frequent drying ups of the YR in its lower reaches. Geologic explorations and grouped-pumping tests were conducted in the area. Based on collected data a groundwater flow net was established. The buried depth of groundwater level and water bearing potential of the aquifers were evaluated. Conventional method was used to determine recharge of the groundwater by lateral infiltration of the YR in pumping patterns. The results show that the study region has a high water bearing potential and offers conditions for the construction of large water works. However, only limited recharge by lateral infiltration from the river is available when developing large scale groundwater exploitation in the riverside of the YR. Environmental impacts induced by embankment stability of the Great dyke of the YR could be minimized or eliminated by appropriate engineering methods.