主办单位Institute of Hydrogeology and Environmental Geology,CAGS;China Chapter,International Association of Hydrogeologists;Commission on Hydrogeology,Geological Society of China
Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and trans...Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and transforming into toxic Cr(VI)due to the presence of manganese oxides in sediments.In this study,Citric Acid(CA)was selected as a representative organic ligand to prepare and characterize Cr(III)-CA complexes.The characteristics,mechanisms and environmental factors influencing the adsorption of Cr(Ⅲ)-CA on porous media(silts and fine sands)were investigated in the study.The results show that Cr(Ⅲ)coordinates with CA at a 1:1 molar ratio,forming stable and soluble Cr(Ⅲ)-CA complexes.Compared to Cr(III)ions,the equilibrium adsorption capacity of Cr(Ⅲ)-CA is an order of magnitude lower in silts and fine sands.The adsorption of Cr(Ⅲ)-CA in silts and fine sands is dominated by chemical adsorption of monolayers,following the pseudo-second-order kinetic equation and the Langmuir isotherm adsorption model.Varying contents of clay minerals and iron-aluminum oxides prove to be the main causes of differences in adsorption capacity of Cr(Ⅲ)-CA in silts and fine sands.Changes in solution pH affect the adsorption rate and capacity of Cr(Ⅲ)-CA by altering its ionic form.The adsorption process is irreversible and only minimally influenced by ionic strength,suggesting that inner-sphere complexation serves as the dominant Cr(Ⅲ)-CA adsorption mechanism.展开更多
The Beijing-Tianjin-Hebei Plain(BTHP)is the political,economic and cultural center of China,where groundwater is the main source of water supply to support social and economic development.Continuous overdraft of the r...The Beijing-Tianjin-Hebei Plain(BTHP)is the political,economic and cultural center of China,where groundwater is the main source of water supply to support social and economic development.Continuous overdraft of the resources has caused a persistent decline of groundwater level and formed a huge cone of depression at a regional scale.This paper addresses current groundwater situation over the BTHP area.The paper also delineates the groundwater flow field,using groundwater level data,in order to provide an effective method for the restoration of groundwater level and associated water resources management.Based on the analysis of multiple factors,such as groundwater level,soil salinization,ground subsidence,groundwater recharge and storage,urban underground space security,formation of fractures,and seawater intrusion,the threshold for groundwater level restoration is defined,and some measures for groundwater over-exploitation management are accordingly proposed.The study shows that:(i)Since the 1980s to 2020,shallow groundwater level in the western part of the BTHP area has dropped by 25 m to 60m,while the cumulative decline of deep groundwater in the central and eastern regions is in the range of 40–80 m;(ii)The water table of the shallow groundwater within the depression zone over the Western Piedmont Plain should be controlled in the range of 15–30 m below ground level(mbgl),while the depth of groundwater level in large and medium-sized urban areas should be controlled within 20–30 mbgl.The groundwater level in the resource preservation area should be controlled within 10–15 mbgl,and the groundwater level in the area with identified soil salinization in the central and eastern plain should be controlled within 3–10 mbgl.However,for the deep groundwater in the central and eastern plainwater,the main focus of the resources management is to control the land subsidence.The water level in the severe land subsidence area should be controlled within 45–60 mbgl,and in the general subsidence area should be controlled within 30–45 mbgl;(iii)Based on the water level recovery threshold and proposed groundwater overdraft management program,if the balance of abstraction and recharge is reached in 2025,the shallow groundwater abstraction needs to be gradually reduced by about 2×10^(8) m^(3).Meanwhile,the ecological water replenishment of rivers through the South-to-North Water Transfer Project should be increased to 28.58×10^(8) m^(3)/a,and the deep groundwater abstraction needs to be gradually reduced by 2.24×10^(8) m^(3).To reach the target of shallow groundwater level in 2040,surface water replacement is recommended with a rate of 25.77×10^(8) m^(3)/a and the ecological water replenishment of rivers in the South-to-North Water Diversion Project should reach 33.51×10^(8) m^(3)/a.For deep groundwater recovery,it is recommended to replace the deep freshwater extraction with the utilization of shallow salt water by 2.82×10^(8) m^(3),in addition to the amount of 7.86×10^(8) m^(3) by water diversion.The results are of great significance to the remediation of groundwater over-exploitation,the regulation of water resources development and utilization,and ecological protection in Beijing-Tianjin-Hebei plain.展开更多
In recent years,drought has become a global issue,especially in arid and semi-arid areas.It is without doubt that the identification and monitoring of the drought phenomenon can help to reduce the damages that would o...In recent years,drought has become a global issue,especially in arid and semi-arid areas.It is without doubt that the identification and monitoring of the drought phenomenon can help to reduce the damages that would occur.In addition,rain is one of the factors which directly affect the water levels of underground water reservoirs.This research applied a linear gradient regression method developed on the basis of GRACE,CHIRPS,and data from monitoring wells to investigate the groundwater storage changes.These data have been analyzed on the Google Earth Engine platform.In order to conduct temporal and spatial analyses,the water levels of the aquifer were generated from the monitoring wells and zoned into five classes.Also,the amount of water storage and rain from the year 2003 to 2017 in the West Azerbaijan Province were investigated using the GRACE satellite and the CHIRPS data,respectively.The results obtained from the GRACE satellite data show that the average water level in the underground reservoirs in Iran had started to decrease since 2008 and reached its peak in 2016 with an average decrease of 16 cm in that year.The average annual decline of groundwater level in the studied time period was 5 cm.A chart developed from the CHIRPS annual rainfall data indicates that the biggest decline in rainfall occurred in 2008,and the declining trend has remained steady.Linear analyses were made on GRACE with CHIRPS results and monitoring wells data separately,from which the correlation coefficients are between 86% and 97%,showing generally high correlations.Furthermore,the results obtained from the zoning of the aquifer showed that in the period of 2004 to 2016,due to the decrease in rainfall and the excessive withdrawal of groundwater,the water levels also decreased.展开更多
The presence of groundwater is strongly related to its geological and geohydrological conditions.It is,however,important to study the groundwater potential in an area before it is utilized to provide clean water.Werne...The presence of groundwater is strongly related to its geological and geohydrological conditions.It is,however,important to study the groundwater potential in an area before it is utilized to provide clean water.Werner-Schlumberger’s method was used to analyze the groundwater potential while hydraulic properties such as soil porosity and hydraulic conductivity were used to determine the quality and ability of the soil to allow water’s movement in the aquifer.The results show that the aquifer in the Sekara and Kemuning Muda is at a depth of more than 6 meters below the ground level with moderate groundwater potential.It is also found that the aquifer at depths of over 60 m have high groundwater potential.Moreover,soil porosity in Kemuning is found to be average while the ability to conduct water was moderate.This makes it possible for some surface water to seep into the soil while the remaining flows to the rivers and ditches.展开更多
After a comprehensive analysis for the influential factors like anti-erodibility chemical constitutes, mineral components and micro-structure characteristics of the Pisha-sandstone, and by combining AHP and grey corre...After a comprehensive analysis for the influential factors like anti-erodibility chemical constitutes, mineral components and micro-structure characteristics of the Pisha-sandstone, and by combining AHP and grey correlation analysis, the anti-erodibility quantitative comparison for 5 types of Pisha-sandstones in Ordos is made on the basis of the grey multi-layer comprehensive assessment mode. The result shows that, from the anti-erodibility point of view, the order of those types is: Pink sandstone, celadon sandstone, purple sandstone, grey sandstone and commixed sandstone. For the evaluation process adopts a simple method, a direct, reasonable and practical result is given, which is also identical to the result of the field survey on soil and rock erosion problems. Consequently, the research on the Pisha-sandstone's anti-erodibility issue is turned from the qualitative description process to the quantitative evaluation stage.展开更多
In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure(CNKI)...In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure(CNKI), which covered the time span from 1984 to present and included more than 2.6 million master and doctoral dissertations from hundreds of institutions of China's Mainland. The bibliometric analysis summarized output, geographical, and institutional patterns, as well as research directions and hotspots in groundwater studies in China in the period of 1984-2014. A total of 1 396 groundwater-related dissertations including 1 161 master dissertations and 235 doctoral dissertations, contributed by 128 institutions distributed in 53 cities nationwide, were searched out in the database. It can be seen obviously that, the groundwater science teaching and research in China has experienced a notable growth in the past three decades especially during 2000-2014. Groundwater modeling, resource, and exploitation were the top three major subject categories; China University of Geosciences(Beijing), Jilin University and Chang’an University were the top three productive institutions together accounting for more than one third of the total dissertations and 50% of the doctoral dissertations, which further prompted the cities(Beijing, Changchun, and Xi’an) to become the top three productive cities. The dissertations generally covered all the international research topics, which indicated that hydrogeologists in China have tracked the international frontier closely during the past decades. The keywords analysis revealed that,(1) numerical modeling was still the hottest topic and PHREEQC, MODFLOW, GMS, and FEFLOW were the four most used softwares;(2) the topics related with groundwater pollution and quality developed steadily and rapidly;(3) environmental isotopes and GIS were frequently used tools for hydrogeological condition analysis, and spatial data processing respectively; and(4) the unsaturated zone as an integral part of aquifers attracted more and more attentions from hydrogeologists focus on saturated zone.展开更多
By analysing the hydrogeological conditions of this region and the coal mines hereof, together with the water hazards troubled Shennan mine area in recent years, this paper summarized six types of mine water hazards. ...By analysing the hydrogeological conditions of this region and the coal mines hereof, together with the water hazards troubled Shennan mine area in recent years, this paper summarized six types of mine water hazards. As per the basic characteristics, geological distribution, threat degree and difficulty of prevention of various water hazards, along with the practice of water prevention in the mining area, this article proposed effective technical measures for the prevention and control of different water hazards and laid a solid foundation for the safe production in the mining area.展开更多
Before 1985, there were a few Chinese participators for International Association of Hydrogeologists which founded in 1956. The Chinese team composed of senior hydrogeologists attended the 17 th and 18 th IAH congress...Before 1985, there were a few Chinese participators for International Association of Hydrogeologists which founded in 1956. The Chinese team composed of senior hydrogeologists attended the 17 th and 18 th IAH congress in 1985. More and more Chinese delegates were present at the conferences since then. The IAH National Chapter of China was first established in 1987 and organized related activities continuously since that time. The IAH members in P.R. China increased in these years. IAH congresses have been hold in China twice. The 21 th congress was held in Guilin City in October, 1988. The 34 th congress was held in Beijing in October, 2006. The IAH China Chapter serves for all IAH members and other scientists promoting groundwater sciences in China. There were a lot of national conferences on Hydrogeology and Groundwater sciences held almost every year since 1987. Those national conferences associate with Commission on Hydrogeology, Geology Society of China in operation. Many Chinese IAH members were the editors and responsible for the Chinese translation for the abstract of Hydrogeology Journal. The Journal of Groundwater Science and Engineering is an international journal for the natural sciences. The sponsors are IAH China chapter, Institute of Hydrogeology and Environmental Geology, CAGS.展开更多
Changes in groundwater level in Homand-Absard plain, located in north-west of Kavir-e-Markazi watershed and east of Tehran province, were studied. The used research method was descriptive approach, and the research st...Changes in groundwater level in Homand-Absard plain, located in north-west of Kavir-e-Markazi watershed and east of Tehran province, were studied. The used research method was descriptive approach, and the research study was conducted based on field and desk surveys. The data needed was provided from field surveys, contours maps, and data of observation wells. There were 17 observation wells in the study area where the changes in groundwater levels were measured during 1996-2013, and an index hydrograph was prepared for the aquifer of plain. The sharpest decline in the groundwater level was in the central of Homan-Absard plain. There was 1.43 m decline in the groundwater level of aquifer annually, compared with similar studies in other parts of Iran, it has a high rate, and to the average, the groundwater level of plain has dropped equal to 25.76 m, 1996-2013. According to the study findings, the groundwater level changes with those in rainfall weren't match and the drop in groundwater level during wet years and then has continued which represents the high water extraction factor on the groundwater level drop.展开更多
Pisha sandstone is a soft rock found in the southern zone of the Inner Mongolia Autonomous Region of Inner Mongolia. The presence of soft Pisha sandstone in the middle reaches of the Yellow River coincides with large ...Pisha sandstone is a soft rock found in the southern zone of the Inner Mongolia Autonomous Region of Inner Mongolia. The presence of soft Pisha sandstone in the middle reaches of the Yellow River coincides with large areas of bedrock erosion in the river’s basin, with the average total erosion modulus as high as 44 570 t/(km^2·a). Such high levels of erosion are one of the main sources of coarse mud and sands in the Yellow River. Erosion by gravitational forces such as snow glide and landslip are the main erosion types in Pisha sandstone region. The gravity erosion modulus can be as high as 25 615 t/(km^2·a), accounting for 30.6% of the total average erosion. Our paper investigates the characteristics of Pisha sandstone in relation to the development of gravity erosion mechanisms. We conducted field investigations in Pisha sandstone region for original state rock sampling. Test results from analyses of the rock properties indicate that the mineral composition, structure and microstructure characteristics of Pisha sandstone determine its varying capacity to resist weathering. Degrees of weathering in slightly different lithological layers of Pisha sandstone lead to different erosion rates. In this way, erosion forces combined with the varying lithological strata in the rock aggravate gravitational erosion in Pisha sandstone.展开更多
In order to prevent the catastrophic events such as extreme drought, continuous drought and source-water quality pollution, 15 groundwater emergency water sources are to be selected in 11 important cities in Hebei, an...In order to prevent the catastrophic events such as extreme drought, continuous drought and source-water quality pollution, 15 groundwater emergency water sources are to be selected in 11 important cities in Hebei, and the evaluation of allowable emergency exploitation quantity is 180.19×10~4 m^3/d. Under the current conditions, the water supply quantity of emergency water sources and the total emergency water supply quantity will meet the emergency water demand with the guarantee rate of 65.79% to 377.78% and 90.35% to 270.51% respectively. By 2020, the water supply quantity of emergency water source places and the total emergency water supply quantity will meet the emergency water demand with the guarantee rate of 22.08% to 74.49% and 82.65% to 144.08% in the benefited areas of South-to-North water diversion(SNWDP); and for non-SNWDP areas, the guarantee rate will be 74.64% to 337.78% and 74.64% to 377.78%.展开更多
Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,...Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.展开更多
The study of temporal and spatial variations of nitrate in groundwater under different soil nitrogen environments is helpful to the security of groundwater resources in agricultural areas.In this paper,based on 320 gr...The study of temporal and spatial variations of nitrate in groundwater under different soil nitrogen environments is helpful to the security of groundwater resources in agricultural areas.In this paper,based on 320 groups of soil and groundwater samples collected at the same time,geostatistical analysis and multiple regression analysis were comprehensively used to conduct the evaluation of nitrogen contents in both groundwater and soil.From May to August,as the nitrification of groundwater is dominant,the average concentration of nitrate nitrogen is 34.80 mg/L;The variation of soil ammonia nitrogen and nitrate nitrogen is moderate from May to July,and the variation coefficient decreased sharply and then increased in August.There is a high correlation between the nitrate nitrogen in groundwater and soil in July,and there is a high correlation between the nitrate nitrogen in groundwater and ammonium nitrogen in soil in August and nitrate nitrogen in soil in July.From May to August,the area of low groundwater nitrate nitrogen in 0-5 mg/L and 5-10 mg/L decreased from 10.97%to 0,and the proportion of high-value area(greater than 70 mg/L)increased from 21.19%to 27.29%.Nitrate nitrogen is the main factor affecting the quality of groundwater.The correlation analysis of nitrate nitrogen in groundwater,nitrate nitrogen in soil and ammonium nitrogen shows that they have a certain period of delay.The areas with high concentration of nitrate in groundwater are mainly concentrated in the western part of the study area,which has a high consistency with the high value areas of soil nitrate distribution from July to August,and a high difference with the spatial position of soil ammonia nitrogen distribution in August.展开更多
This paper presents a new analytical solution to investigate the mechanism of transient confinedunconfined flow in a confined aquifer induced by pumping with a large rate during mine drainage.The study focuses on unde...This paper presents a new analytical solution to investigate the mechanism of transient confinedunconfined flow in a confined aquifer induced by pumping with a large rate during mine drainage.The study focuses on understanding the impact of non-Darcian effect on flow towards a fully penetrated pumping well.The nonlinear relationship between specific discharge and the hydraulic gradient is described using Izbash's equation.A novel approximate method is developed to linearize the mathematical model,and the solution is derived using the Boltzmann transform.The proposed solution is validated by comparing it with previous works.The findings indicate that increased non-Darcian index,quasi-hydraulic conductivity,and specific storage have negatively affect the development of the unconfined region and aquifer drawdown,as greater turbulence flow accelerates recharge to the pumping well.Drawdown is found to be sensitive to the non-Darcian index,quasi-hydraulic conductivity,while it is unaffected by specific yield and specific storage.The conclusions provide valuable insights for mine drainage and the application of geological and hydrological conditions.展开更多
Termite mounds are conventionally surmised as one of the best bio-geological indicator for groundwater occurrence in places where they inhibit.Ground magnetic survey was carried out to prove the assumption about termi...Termite mounds are conventionally surmised as one of the best bio-geological indicator for groundwater occurrence in places where they inhibit.Ground magnetic survey was carried out to prove the assumption about termite mounds as an important indicator for groundwater exploration.Occurrences of 18 Termite mounds were mapped using handheld GPS to identify the suitable trend for magnetic survey.After considering all the criteria such as power lines,fences and fracture system,termite mound 2,12 and 18 were selected in the NNE-SSW trend,and the ground magnetic survey was conducted in ESE-WNW direction which is perpendicular to the trend of the termite mounds using Proton Precession Magnetometer.Totally,99 samples were collected with 5 m sampling interval and 50 m profile interval over an area of 22500 sq.m.The magnetic values varied from–7363 nT to 898 nT with the mean of–331 nT.Processed map of reduction to Equator indicates the presence of NNE-SSW and WNW-ESE magnetic breaks.Analytical signal map designated the presence of magnetic low in the WNW-ESE direction which coincides spatially with the magnetic breaks.The magnetic profile lines have also brought to light the structurally weak zones.Causative body depth range was estimated using power spectrum and Euler method which are from 120 m to 40 m and<20 m to>100 m,respectively.The present study appreciably brings out the spatial relationship between the termite mounds and the hydro-fractures.This confirms the assertion with regard to termite mounds as an effective tool for groundwater exploration.展开更多
Due to energy shortage and increasing environmental awareness, resources in shallow underground space have been rapidly exploited and utilized. So that studying variation characteristics of geothermal response in gnei...Due to energy shortage and increasing environmental awareness, resources in shallow underground space have been rapidly exploited and utilized. So that studying variation characteristics of geothermal response in gneiss is necessary for effective and rational use of underground heat. Based on field test of thermal response in gneiss under hydrogeological survey project carried out in shallow geothermal energy development zone in Liaoning Province, this thesis analyzes mathematical statistics of geothermal response characteristics in main gneiss of Laoning Province. The initial formation temperature ranges from 10.80℃ to 15.80℃ according to field test. The statistical results show that in the condition of natural water content, the average thermal conductivity of Quaternary loose rocks comes as clay< silty< silty fine sand< medium sand< coarse sand< gravelly sand. This order is consistent with thermal conductivity characteristics of gneiss obtained in the laboratory. Formation temperature recovery in different strata follows as granite> medium sand> clay. This order is opposite to the absolute value of temperature recovery curve slope of corresponding lithology, which shows that the stratum with higher temperature recovery rate has lower temperature recovery curve slope.展开更多
Understanding the infiltration process and quantifying recharge are critical for effective water resources management,particularly in arid and semi-arid regions.However,factors influencing on recharge process under di...Understanding the infiltration process and quantifying recharge are critical for effective water resources management,particularly in arid and semi-arid regions.However,factors influencing on recharge process under different land use types in irrigation districts remain unclear.In this study,a Brilliant Blue FCF dye tracer experiment was conducted to investigate infiltration pathways under the cotton field,pear orchard,and bare land conditions in the Kongque Rive Irrigation District of Xinjiang,China.Recharge rates were estimated using the chloride mass balance method.The results show that the average preferential flow ratio was highest in the bare land(50.42%),followed by the cotton field(30.09%)and pear orchard(23.59%).Matrix flow was the dominant infiltration pathway in the pear orchard and cotton field.Irrigation method was a primary factor influencing recharge rates,with surface irrigation promoting deeper infiltration compared to drip irrigation.Under the drip irrigation mode,the recharge of cotton fields ranged from 23.47 mm/a to 59.16 mm/a.In comparison,the recharge of surface irrigation in pear orchards contributed between 154.30 mm/a and 401.65 mm/a.These findings provide valuable insights into soil water infiltration and recharge processes under typical land use conditions in the Kongque River Irrigation District,supporting improved irrigation management and sustainable water resource utilization.展开更多
Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle ...Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle in the Wadi Mina upstream watershed(northwest Algeria)by applying the Soil and Water Assessment Tool(SWAT)hydrological model.SWAT modelling integrates spatial data such as the Digital Elevation Model(DEM),land use,soil types and various meteorological parameters including precipitation,maximum and minimum temperatures,relative humidity,solar radiation and wind speed.The SWAT model was calibrated and validated using data from January 2012 to December 2014,with a calibra-tion period from January 2012 to August 2013 and a validation period from September 2013 to December 2014.Sensitivity and parameter calibration were conducted using the SWAT-SA program,and model performance evaluation relied on comparing the observed discharge at the outlet of the basin with model-simulated discharge,assessed through statistical coefficients including Nash-Sutcliffe Efficiency(NSE),coefficient of determination(R2)and Percent Bias(PBAIS).Calibration results indicated favourable objec-tive function values(NSE=0.79,R2=0.93,PBAIS=-8.53%),although a slight decrease was observed during validation(NSE=0.69,R2=0.86,and PBAIS=-11.41%).The application of the SWAT model to the Wadi Mina upstream watershed highlighted its utility in simulating the spatial distribution of different components of the hydrological balance in this basin.The SWAT model revealed that approximately 71%of the precipitation in the basin evaporates,while only 29%contributes to surface runoff or infiltration into the soil.展开更多
The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of fluids.Numerical simula...The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of fluids.Numerical simulation is an effective way to study groundwater flow system.In this paper,the ideal model is generalized according to the fundamental characteristics of groundwater system in inland basins of Western China.The simulation method of variable density flow on the development of groundwater system in inland basins is established by using EOS9 module in TOUGHREACT numerical simulation software.In accordance with the groundwater streamline,the groundwater flow system is divided into three levels,which are regional groundwater flow system,intermediate groundwater flow system and local groundwater flow system.Based on the calculation of the renewal rate of groundwater,the analysis shows that the increase of fluid density in the central part of the basin will restrain the development of regional groundwater flow system,resulting in a decrease of the circulation rate from 32.28% to 17.62% and a certain enhancement to the local groundwater flow system,which increased from 37.29% to 51.94%.展开更多
This paper studies the distribution features, the chemical elements beyond standards and the influencing factors of shallow groundwater quality in the Guanzhong Basin through the data monitored in the last twenty year...This paper studies the distribution features, the chemical elements beyond standards and the influencing factors of shallow groundwater quality in the Guanzhong Basin through the data monitored in the last twenty years. The final purpose is to comprehensively evaluate the divisions of groundwater quality in the Guanzhong Basin. Results show that, the groundwater quality is in good shape, and suitable for drinking. Drinking accounts for 16.02% of the total, most of which are distributed in the lubotan of Weibei. Some come from loess plateau of Qian-Liquan County and some are generated by the industrial pollution of Xingping City. Materials exceeding standards include chloride, sulfate, three nitrogen, fluoride, manganese, iron, hexavalent chromium and so on. The main factors influencing the quality of shallow groundwater include groundwater exploitation, natural background value of special components and precipitation, among which the groundwater exploitation poses the greatest impact. The depth of water is positively correlated with the concentration of sulfate, nitrate and total hardness.展开更多
基金financially supported jointly by Natural Science Foundation of Fujian Province of China(NO.2023J01227)Natural Science Foundation of Hebei Province(NO.D2020504003)Key Laboratory of Groundwater Remediation of Hebei Province and China Geological Survey(NO.SK202303).
文摘Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and transforming into toxic Cr(VI)due to the presence of manganese oxides in sediments.In this study,Citric Acid(CA)was selected as a representative organic ligand to prepare and characterize Cr(III)-CA complexes.The characteristics,mechanisms and environmental factors influencing the adsorption of Cr(Ⅲ)-CA on porous media(silts and fine sands)were investigated in the study.The results show that Cr(Ⅲ)coordinates with CA at a 1:1 molar ratio,forming stable and soluble Cr(Ⅲ)-CA complexes.Compared to Cr(III)ions,the equilibrium adsorption capacity of Cr(Ⅲ)-CA is an order of magnitude lower in silts and fine sands.The adsorption of Cr(Ⅲ)-CA in silts and fine sands is dominated by chemical adsorption of monolayers,following the pseudo-second-order kinetic equation and the Langmuir isotherm adsorption model.Varying contents of clay minerals and iron-aluminum oxides prove to be the main causes of differences in adsorption capacity of Cr(Ⅲ)-CA in silts and fine sands.Changes in solution pH affect the adsorption rate and capacity of Cr(Ⅲ)-CA by altering its ionic form.The adsorption process is irreversible and only minimally influenced by ionic strength,suggesting that inner-sphere complexation serves as the dominant Cr(Ⅲ)-CA adsorption mechanism.
基金funded by Geological survey project of China Geological Survey (DD20190336, DD20221752)。
文摘The Beijing-Tianjin-Hebei Plain(BTHP)is the political,economic and cultural center of China,where groundwater is the main source of water supply to support social and economic development.Continuous overdraft of the resources has caused a persistent decline of groundwater level and formed a huge cone of depression at a regional scale.This paper addresses current groundwater situation over the BTHP area.The paper also delineates the groundwater flow field,using groundwater level data,in order to provide an effective method for the restoration of groundwater level and associated water resources management.Based on the analysis of multiple factors,such as groundwater level,soil salinization,ground subsidence,groundwater recharge and storage,urban underground space security,formation of fractures,and seawater intrusion,the threshold for groundwater level restoration is defined,and some measures for groundwater over-exploitation management are accordingly proposed.The study shows that:(i)Since the 1980s to 2020,shallow groundwater level in the western part of the BTHP area has dropped by 25 m to 60m,while the cumulative decline of deep groundwater in the central and eastern regions is in the range of 40–80 m;(ii)The water table of the shallow groundwater within the depression zone over the Western Piedmont Plain should be controlled in the range of 15–30 m below ground level(mbgl),while the depth of groundwater level in large and medium-sized urban areas should be controlled within 20–30 mbgl.The groundwater level in the resource preservation area should be controlled within 10–15 mbgl,and the groundwater level in the area with identified soil salinization in the central and eastern plain should be controlled within 3–10 mbgl.However,for the deep groundwater in the central and eastern plainwater,the main focus of the resources management is to control the land subsidence.The water level in the severe land subsidence area should be controlled within 45–60 mbgl,and in the general subsidence area should be controlled within 30–45 mbgl;(iii)Based on the water level recovery threshold and proposed groundwater overdraft management program,if the balance of abstraction and recharge is reached in 2025,the shallow groundwater abstraction needs to be gradually reduced by about 2×10^(8) m^(3).Meanwhile,the ecological water replenishment of rivers through the South-to-North Water Transfer Project should be increased to 28.58×10^(8) m^(3)/a,and the deep groundwater abstraction needs to be gradually reduced by 2.24×10^(8) m^(3).To reach the target of shallow groundwater level in 2040,surface water replacement is recommended with a rate of 25.77×10^(8) m^(3)/a and the ecological water replenishment of rivers in the South-to-North Water Diversion Project should reach 33.51×10^(8) m^(3)/a.For deep groundwater recovery,it is recommended to replace the deep freshwater extraction with the utilization of shallow salt water by 2.82×10^(8) m^(3),in addition to the amount of 7.86×10^(8) m^(3) by water diversion.The results are of great significance to the remediation of groundwater over-exploitation,the regulation of water resources development and utilization,and ecological protection in Beijing-Tianjin-Hebei plain.
文摘In recent years,drought has become a global issue,especially in arid and semi-arid areas.It is without doubt that the identification and monitoring of the drought phenomenon can help to reduce the damages that would occur.In addition,rain is one of the factors which directly affect the water levels of underground water reservoirs.This research applied a linear gradient regression method developed on the basis of GRACE,CHIRPS,and data from monitoring wells to investigate the groundwater storage changes.These data have been analyzed on the Google Earth Engine platform.In order to conduct temporal and spatial analyses,the water levels of the aquifer were generated from the monitoring wells and zoned into five classes.Also,the amount of water storage and rain from the year 2003 to 2017 in the West Azerbaijan Province were investigated using the GRACE satellite and the CHIRPS data,respectively.The results obtained from the GRACE satellite data show that the average water level in the underground reservoirs in Iran had started to decrease since 2008 and reached its peak in 2016 with an average decrease of 16 cm in that year.The average annual decline of groundwater level in the studied time period was 5 cm.A chart developed from the CHIRPS annual rainfall data indicates that the biggest decline in rainfall occurred in 2008,and the declining trend has remained steady.Linear analyses were made on GRACE with CHIRPS results and monitoring wells data separately,from which the correlation coefficients are between 86% and 97%,showing generally high correlations.Furthermore,the results obtained from the zoning of the aquifer showed that in the period of 2004 to 2016,due to the decrease in rainfall and the excessive withdrawal of groundwater,the water levels also decreased.
文摘The presence of groundwater is strongly related to its geological and geohydrological conditions.It is,however,important to study the groundwater potential in an area before it is utilized to provide clean water.Werner-Schlumberger’s method was used to analyze the groundwater potential while hydraulic properties such as soil porosity and hydraulic conductivity were used to determine the quality and ability of the soil to allow water’s movement in the aquifer.The results show that the aquifer in the Sekara and Kemuning Muda is at a depth of more than 6 meters below the ground level with moderate groundwater potential.It is also found that the aquifer at depths of over 60 m have high groundwater potential.Moreover,soil porosity in Kemuning is found to be average while the ability to conduct water was moderate.This makes it possible for some surface water to seep into the soil while the remaining flows to the rivers and ditches.
基金financed by the basic scientific research project fund of the Institute of Hydrogeology and Environmental Geology of Chinese Academy of Geological Sciences(No.SK 201403)
文摘After a comprehensive analysis for the influential factors like anti-erodibility chemical constitutes, mineral components and micro-structure characteristics of the Pisha-sandstone, and by combining AHP and grey correlation analysis, the anti-erodibility quantitative comparison for 5 types of Pisha-sandstones in Ordos is made on the basis of the grey multi-layer comprehensive assessment mode. The result shows that, from the anti-erodibility point of view, the order of those types is: Pink sandstone, celadon sandstone, purple sandstone, grey sandstone and commixed sandstone. For the evaluation process adopts a simple method, a direct, reasonable and practical result is given, which is also identical to the result of the field survey on soil and rock erosion problems. Consequently, the research on the Pisha-sandstone's anti-erodibility issue is turned from the qualitative description process to the quantitative evaluation stage.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (2014ZX07201-010)the National Natural Science Foundation of China (41302179)the Fundamental Research Funds for the Central Universities (2013YB64)
文摘In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure(CNKI), which covered the time span from 1984 to present and included more than 2.6 million master and doctoral dissertations from hundreds of institutions of China's Mainland. The bibliometric analysis summarized output, geographical, and institutional patterns, as well as research directions and hotspots in groundwater studies in China in the period of 1984-2014. A total of 1 396 groundwater-related dissertations including 1 161 master dissertations and 235 doctoral dissertations, contributed by 128 institutions distributed in 53 cities nationwide, were searched out in the database. It can be seen obviously that, the groundwater science teaching and research in China has experienced a notable growth in the past three decades especially during 2000-2014. Groundwater modeling, resource, and exploitation were the top three major subject categories; China University of Geosciences(Beijing), Jilin University and Chang’an University were the top three productive institutions together accounting for more than one third of the total dissertations and 50% of the doctoral dissertations, which further prompted the cities(Beijing, Changchun, and Xi’an) to become the top three productive cities. The dissertations generally covered all the international research topics, which indicated that hydrogeologists in China have tracked the international frontier closely during the past decades. The keywords analysis revealed that,(1) numerical modeling was still the hottest topic and PHREEQC, MODFLOW, GMS, and FEFLOW were the four most used softwares;(2) the topics related with groundwater pollution and quality developed steadily and rapidly;(3) environmental isotopes and GIS were frequently used tools for hydrogeological condition analysis, and spatial data processing respectively; and(4) the unsaturated zone as an integral part of aquifers attracted more and more attentions from hydrogeologists focus on saturated zone.
文摘By analysing the hydrogeological conditions of this region and the coal mines hereof, together with the water hazards troubled Shennan mine area in recent years, this paper summarized six types of mine water hazards. As per the basic characteristics, geological distribution, threat degree and difficulty of prevention of various water hazards, along with the practice of water prevention in the mining area, this article proposed effective technical measures for the prevention and control of different water hazards and laid a solid foundation for the safe production in the mining area.
文摘Before 1985, there were a few Chinese participators for International Association of Hydrogeologists which founded in 1956. The Chinese team composed of senior hydrogeologists attended the 17 th and 18 th IAH congress in 1985. More and more Chinese delegates were present at the conferences since then. The IAH National Chapter of China was first established in 1987 and organized related activities continuously since that time. The IAH members in P.R. China increased in these years. IAH congresses have been hold in China twice. The 21 th congress was held in Guilin City in October, 1988. The 34 th congress was held in Beijing in October, 2006. The IAH China Chapter serves for all IAH members and other scientists promoting groundwater sciences in China. There were a lot of national conferences on Hydrogeology and Groundwater sciences held almost every year since 1987. Those national conferences associate with Commission on Hydrogeology, Geology Society of China in operation. Many Chinese IAH members were the editors and responsible for the Chinese translation for the abstract of Hydrogeology Journal. The Journal of Groundwater Science and Engineering is an international journal for the natural sciences. The sponsors are IAH China chapter, Institute of Hydrogeology and Environmental Geology, CAGS.
文摘Changes in groundwater level in Homand-Absard plain, located in north-west of Kavir-e-Markazi watershed and east of Tehran province, were studied. The used research method was descriptive approach, and the research study was conducted based on field and desk surveys. The data needed was provided from field surveys, contours maps, and data of observation wells. There were 17 observation wells in the study area where the changes in groundwater levels were measured during 1996-2013, and an index hydrograph was prepared for the aquifer of plain. The sharpest decline in the groundwater level was in the central of Homan-Absard plain. There was 1.43 m decline in the groundwater level of aquifer annually, compared with similar studies in other parts of Iran, it has a high rate, and to the average, the groundwater level of plain has dropped equal to 25.76 m, 1996-2013. According to the study findings, the groundwater level changes with those in rainfall weren't match and the drop in groundwater level during wet years and then has continued which represents the high water extraction factor on the groundwater level drop.
基金supported by the public program of Ministry of Science and Technology of China (Grant No 2005DIB3J068)
文摘Pisha sandstone is a soft rock found in the southern zone of the Inner Mongolia Autonomous Region of Inner Mongolia. The presence of soft Pisha sandstone in the middle reaches of the Yellow River coincides with large areas of bedrock erosion in the river’s basin, with the average total erosion modulus as high as 44 570 t/(km^2·a). Such high levels of erosion are one of the main sources of coarse mud and sands in the Yellow River. Erosion by gravitational forces such as snow glide and landslip are the main erosion types in Pisha sandstone region. The gravity erosion modulus can be as high as 25 615 t/(km^2·a), accounting for 30.6% of the total average erosion. Our paper investigates the characteristics of Pisha sandstone in relation to the development of gravity erosion mechanisms. We conducted field investigations in Pisha sandstone region for original state rock sampling. Test results from analyses of the rock properties indicate that the mineral composition, structure and microstructure characteristics of Pisha sandstone determine its varying capacity to resist weathering. Degrees of weathering in slightly different lithological layers of Pisha sandstone lead to different erosion rates. In this way, erosion forces combined with the varying lithological strata in the rock aggravate gravitational erosion in Pisha sandstone.
文摘In order to prevent the catastrophic events such as extreme drought, continuous drought and source-water quality pollution, 15 groundwater emergency water sources are to be selected in 11 important cities in Hebei, and the evaluation of allowable emergency exploitation quantity is 180.19×10~4 m^3/d. Under the current conditions, the water supply quantity of emergency water sources and the total emergency water supply quantity will meet the emergency water demand with the guarantee rate of 65.79% to 377.78% and 90.35% to 270.51% respectively. By 2020, the water supply quantity of emergency water source places and the total emergency water supply quantity will meet the emergency water demand with the guarantee rate of 22.08% to 74.49% and 82.65% to 144.08% in the benefited areas of South-to-North water diversion(SNWDP); and for non-SNWDP areas, the guarantee rate will be 74.64% to 337.78% and 74.64% to 377.78%.
基金supported by the China Geological Survey Project(Nos.DD20220864 and DD20243077).
文摘Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.
基金Youth Fund of National Natural Science Foundation of China (42101353)the Ministry of Housing and Urban-Rural Development Science Plan Project (2022-R-063)Liaoning Social Science Planning Fund Project (L21BGL046)。
文摘The study of temporal and spatial variations of nitrate in groundwater under different soil nitrogen environments is helpful to the security of groundwater resources in agricultural areas.In this paper,based on 320 groups of soil and groundwater samples collected at the same time,geostatistical analysis and multiple regression analysis were comprehensively used to conduct the evaluation of nitrogen contents in both groundwater and soil.From May to August,as the nitrification of groundwater is dominant,the average concentration of nitrate nitrogen is 34.80 mg/L;The variation of soil ammonia nitrogen and nitrate nitrogen is moderate from May to July,and the variation coefficient decreased sharply and then increased in August.There is a high correlation between the nitrate nitrogen in groundwater and soil in July,and there is a high correlation between the nitrate nitrogen in groundwater and ammonium nitrogen in soil in August and nitrate nitrogen in soil in July.From May to August,the area of low groundwater nitrate nitrogen in 0-5 mg/L and 5-10 mg/L decreased from 10.97%to 0,and the proportion of high-value area(greater than 70 mg/L)increased from 21.19%to 27.29%.Nitrate nitrogen is the main factor affecting the quality of groundwater.The correlation analysis of nitrate nitrogen in groundwater,nitrate nitrogen in soil and ammonium nitrogen shows that they have a certain period of delay.The areas with high concentration of nitrate in groundwater are mainly concentrated in the western part of the study area,which has a high consistency with the high value areas of soil nitrate distribution from July to August,and a high difference with the spatial position of soil ammonia nitrogen distribution in August.
基金supported by the national natural science foundation of China(Grant Numbers 41807197,2017YFC0405900,and 51469002)the natural science foundation of Guangxi(Grant Numbers 2017GXNSFBA198087,2018GXNSFAA 138042,and GuiKeAB17195073)Hebei high level talent funding project(B2018003016).
文摘This paper presents a new analytical solution to investigate the mechanism of transient confinedunconfined flow in a confined aquifer induced by pumping with a large rate during mine drainage.The study focuses on understanding the impact of non-Darcian effect on flow towards a fully penetrated pumping well.The nonlinear relationship between specific discharge and the hydraulic gradient is described using Izbash's equation.A novel approximate method is developed to linearize the mathematical model,and the solution is derived using the Boltzmann transform.The proposed solution is validated by comparing it with previous works.The findings indicate that increased non-Darcian index,quasi-hydraulic conductivity,and specific storage have negatively affect the development of the unconfined region and aquifer drawdown,as greater turbulence flow accelerates recharge to the pumping well.Drawdown is found to be sensitive to the non-Darcian index,quasi-hydraulic conductivity,while it is unaffected by specific yield and specific storage.The conclusions provide valuable insights for mine drainage and the application of geological and hydrological conditions.
文摘Termite mounds are conventionally surmised as one of the best bio-geological indicator for groundwater occurrence in places where they inhibit.Ground magnetic survey was carried out to prove the assumption about termite mounds as an important indicator for groundwater exploration.Occurrences of 18 Termite mounds were mapped using handheld GPS to identify the suitable trend for magnetic survey.After considering all the criteria such as power lines,fences and fracture system,termite mound 2,12 and 18 were selected in the NNE-SSW trend,and the ground magnetic survey was conducted in ESE-WNW direction which is perpendicular to the trend of the termite mounds using Proton Precession Magnetometer.Totally,99 samples were collected with 5 m sampling interval and 50 m profile interval over an area of 22500 sq.m.The magnetic values varied from–7363 nT to 898 nT with the mean of–331 nT.Processed map of reduction to Equator indicates the presence of NNE-SSW and WNW-ESE magnetic breaks.Analytical signal map designated the presence of magnetic low in the WNW-ESE direction which coincides spatially with the magnetic breaks.The magnetic profile lines have also brought to light the structurally weak zones.Causative body depth range was estimated using power spectrum and Euler method which are from 120 m to 40 m and<20 m to>100 m,respectively.The present study appreciably brings out the spatial relationship between the termite mounds and the hydro-fractures.This confirms the assertion with regard to termite mounds as an effective tool for groundwater exploration.
基金supported by Geological Investigation(12120114086501-25)which is supported by Geological Survey of China
文摘Due to energy shortage and increasing environmental awareness, resources in shallow underground space have been rapidly exploited and utilized. So that studying variation characteristics of geothermal response in gneiss is necessary for effective and rational use of underground heat. Based on field test of thermal response in gneiss under hydrogeological survey project carried out in shallow geothermal energy development zone in Liaoning Province, this thesis analyzes mathematical statistics of geothermal response characteristics in main gneiss of Laoning Province. The initial formation temperature ranges from 10.80℃ to 15.80℃ according to field test. The statistical results show that in the condition of natural water content, the average thermal conductivity of Quaternary loose rocks comes as clay< silty< silty fine sand< medium sand< coarse sand< gravelly sand. This order is consistent with thermal conductivity characteristics of gneiss obtained in the laboratory. Formation temperature recovery in different strata follows as granite> medium sand> clay. This order is opposite to the absolute value of temperature recovery curve slope of corresponding lithology, which shows that the stratum with higher temperature recovery rate has lower temperature recovery curve slope.
基金supported by the Hydrogeological Investigation Project in Kaidu River and Kongque River Basin in Xinjiang,China(No.DD2020171)the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shaanxi Province(No.2020006).
文摘Understanding the infiltration process and quantifying recharge are critical for effective water resources management,particularly in arid and semi-arid regions.However,factors influencing on recharge process under different land use types in irrigation districts remain unclear.In this study,a Brilliant Blue FCF dye tracer experiment was conducted to investigate infiltration pathways under the cotton field,pear orchard,and bare land conditions in the Kongque Rive Irrigation District of Xinjiang,China.Recharge rates were estimated using the chloride mass balance method.The results show that the average preferential flow ratio was highest in the bare land(50.42%),followed by the cotton field(30.09%)and pear orchard(23.59%).Matrix flow was the dominant infiltration pathway in the pear orchard and cotton field.Irrigation method was a primary factor influencing recharge rates,with surface irrigation promoting deeper infiltration compared to drip irrigation.Under the drip irrigation mode,the recharge of cotton fields ranged from 23.47 mm/a to 59.16 mm/a.In comparison,the recharge of surface irrigation in pear orchards contributed between 154.30 mm/a and 401.65 mm/a.These findings provide valuable insights into soil water infiltration and recharge processes under typical land use conditions in the Kongque River Irrigation District,supporting improved irrigation management and sustainable water resource utilization.
文摘Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle in the Wadi Mina upstream watershed(northwest Algeria)by applying the Soil and Water Assessment Tool(SWAT)hydrological model.SWAT modelling integrates spatial data such as the Digital Elevation Model(DEM),land use,soil types and various meteorological parameters including precipitation,maximum and minimum temperatures,relative humidity,solar radiation and wind speed.The SWAT model was calibrated and validated using data from January 2012 to December 2014,with a calibra-tion period from January 2012 to August 2013 and a validation period from September 2013 to December 2014.Sensitivity and parameter calibration were conducted using the SWAT-SA program,and model performance evaluation relied on comparing the observed discharge at the outlet of the basin with model-simulated discharge,assessed through statistical coefficients including Nash-Sutcliffe Efficiency(NSE),coefficient of determination(R2)and Percent Bias(PBAIS).Calibration results indicated favourable objec-tive function values(NSE=0.79,R2=0.93,PBAIS=-8.53%),although a slight decrease was observed during validation(NSE=0.69,R2=0.86,and PBAIS=-11.41%).The application of the SWAT model to the Wadi Mina upstream watershed highlighted its utility in simulating the spatial distribution of different components of the hydrological balance in this basin.The SWAT model revealed that approximately 71%of the precipitation in the basin evaporates,while only 29%contributes to surface runoff or infiltration into the soil.
基金jointly funded by the National Natural Science Foundation of China (41702282, 41602268)China Geological Survey Project (DD20160311, DD20160238)the Basic Research Service Fee of the Chinese Academy of Geological Sciences (YYWF201626)
文摘The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of fluids.Numerical simulation is an effective way to study groundwater flow system.In this paper,the ideal model is generalized according to the fundamental characteristics of groundwater system in inland basins of Western China.The simulation method of variable density flow on the development of groundwater system in inland basins is established by using EOS9 module in TOUGHREACT numerical simulation software.In accordance with the groundwater streamline,the groundwater flow system is divided into three levels,which are regional groundwater flow system,intermediate groundwater flow system and local groundwater flow system.Based on the calculation of the renewal rate of groundwater,the analysis shows that the increase of fluid density in the central part of the basin will restrain the development of regional groundwater flow system,resulting in a decrease of the circulation rate from 32.28% to 17.62% and a certain enhancement to the local groundwater flow system,which increased from 37.29% to 51.94%.
基金sponsored by the construction of urban geological environment monitoring network in Guanzhong urban agglomeration,China geological survey,Project No.Water[2012]01-007-002the research of groundwater dynamic monitoring in Shaanxi province,Shaanxi public welfare geological project,Project No.20130203
文摘This paper studies the distribution features, the chemical elements beyond standards and the influencing factors of shallow groundwater quality in the Guanzhong Basin through the data monitored in the last twenty years. The final purpose is to comprehensively evaluate the divisions of groundwater quality in the Guanzhong Basin. Results show that, the groundwater quality is in good shape, and suitable for drinking. Drinking accounts for 16.02% of the total, most of which are distributed in the lubotan of Weibei. Some come from loess plateau of Qian-Liquan County and some are generated by the industrial pollution of Xingping City. Materials exceeding standards include chloride, sulfate, three nitrogen, fluoride, manganese, iron, hexavalent chromium and so on. The main factors influencing the quality of shallow groundwater include groundwater exploitation, natural background value of special components and precipitation, among which the groundwater exploitation poses the greatest impact. The depth of water is positively correlated with the concentration of sulfate, nitrate and total hardness.
