陕西秦岭翠华山泉水化学成分研究

为了研究泉水化学成分特点和在一年内的变化,文章利用pH-电导率自动记录仪对陕西秦岭翠华山地区两处泉水化学成分进行了每月2次的观测,并进行了水化学分析。翠华山泉水中HCO-3含量在76.27～152.55mg/L之间,Ca_²⁺含量在14.48～26.92mg/L之间,Mg²⁺含量在4.46～4.89mg/L之间,K⁺含量在0.60～2.75mg/L之间,Na⁺含量在0.93～1.09mg/L之间,这些成分的特点是含量低。泉水pH值在6.98～5.69之间,夏秋季低于该区雨水的pH值,具酸性特征,这是该区地层主要由片麻岩构成决定的。从1月到11月,水秋池村泉水pH值和电导率呈现由大到小再到大的变化规律,引起这种变化的主要原因是夏秋季土壤CO₂含量比冬春季高,泉水在夏秋季流动过程中吸收了较多的CO₂。翠华湖西泉水pH值和Ca²⁺,Mg²⁺,K⁺,Na⁺离子含量比水秋池泉水高,从1月到11月Ca²⁺,Mg²⁺,K⁺,Na⁺离子含量变化与水秋池泉水变化相反,这应当是两个泉水的来源不同或在流动过程中遇到了酸碱性不同的土层和地层造成的。翠华山地区泉水化学成分变化是易于观测到的规律性很强的变化。     

Carbonate chemistry of groundwater from chalk,Givendale, East Yorkshire

Precipitation, soil and spring waters from an outlier of Chalk were analysed over a one year period for field pH, and contents of Ca⁺², Mg⁺², HCO₃^? and other dissolved solids. Measured soil log PCO₂ (atm) varied between a minimum of ?2.60 and maximum of ?1.46, and could be predicted from measurements of soil temperature. Soil waters evolved under open system conditions with respect to soil CO₂, and were undersaturated with calcite during the winter recharge period.The chemistry of the springs is related to their topographic position. Group 1 springs, located below a feather edge of chalk, had both their minimum and maximum PCO₂s predicted by the soil CO₂ data, suggesting open system CO₂ evolution. Group 2 springs, located along the scarp slope had minimum PCO₂s predicted by the soil data, but maximum PCO₂s which could only be explained by a closed system evolution from the maximum soil CO₂ observed. Group 1 springs were close to calcite saturation, whereas Group 2 springs were significantly undersaturated with calcite. The two groups could be identified by linear discriminant analysis of measured Ca²⁺, pH and HCO₃^? concentrations.     

Quality of spring water used for irrigation in the Almora District of Uttarakhand, India

This paper aims to propose a quality profile of springs of the study area for irrigation. In the present study, fifty-four springs in Almora have been identified from rural as well as urban localities for calculation of irriga- tional water quality parameters during pre-monsoon, monsoon and post-monsoon, 2008. Spring water samples are collected and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), Na+ , K+ , Ca2+ , Mg2+ , HCO3- , Cl- , and SO42- . Different irrigation quality parameters viz. salinity, sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium carbonate (RSC), magnesium hazards (MH) and permeability index (PI) are calculated for the evaluation of spring water quality for irrigation purposes. All springs are found excellent to good based on irrigation quality parameters. Based on Wilcox diagram, about 98% of the water resources are grouped as C1S1 (low-low) and C2S1 (medium-low) classes, so springs are suitable for normal irrigation.     

Chemistry of perennial springs of Bhetagad watershed: a case study from central Himalayas,India

A field study was conducted to assess the location and the seasonal variation in physicochemical parameters of springs (outlets of underground water channels) of Bhetagad watershed of Uttaranchal hills, India. Traditionally, spring water is used for multiple purposes in this region. The average population density of the watershed is 366 persons km^?2, distributed within an altitudinal range of 1,090–2,060 m a.m.s.l. and 23.52 km² area. Twelve springs, in three different land uses e.g. pine forest, rainfed agriculture near settlements and irrigated agriculture near settlements were monitored in the winter (January), summer (June) and monsoon (August) during 1998 and 1999. The water quality parameters selected, in the present study are pH, EC, TDS, DO, free CO₂, total hardness, Ca²⁺, Mg²⁺, CO₃^2?, HCO₃^?, Cl^-, NO₃^? and SO₄^2? ions. Some springs in pine forests exhibit lower pH values than the permissible limit. Springs, with their location in agriculture and settlement, show slightly higher EC than the springs in pine forests. All the springs, near the irrigated agricultural land recorded higher nitrate ion concentration.     

A 17-Year Record of Environmental Tracers in Spring Discharge,Shenandoah National Park,Virginia, USA: Use of Climatic Data and Environmental Conditions to Interpret Discharge,Dissolved Solutes,and Tracer Concentrations

A 17-year record (1995–2012) of a suite of environmental tracer concentrations in discharge from 34 springs located along the crest of the Blue Ridge Mountains in Shenandoah National Park (SNP), Virginia, USA, reveals patterns and trends that can be related to climatic and environmental conditions. These data include a 12-year time series of monthly sampling at five springs, with measurements of temperature, specific conductance, pH, and discharge recorded at 30-min intervals. The monthly measurements include age tracers (CFC-11, CFC-12, CFC-113, CFC-13, SF₆, and SF₅CF₃), dissolved gases (N₂, O₂, Ar, CO₂, and CH₄), stable isotopes of water, and major and trace inorganic constituents. The chlorofluorocarbon (CFC) and sulfur hexafluoride (SF₆₎ concentrations (in pptv) in spring discharge closely follow the concurrent monthly measurements of their atmospheric mixing ratios measured at the Air Monitoring Station at Big Meadows, SNP, indicating waters 0–3 years in age. A 2-year (2001–2003) record of unsaturated zone air displayed seasonal deviations from North American Air of ±10 % for CFC-11 and CFC-113, with excess CFC-11 and CFC-113 in peak summer and depletion in peak winter. The pattern in unsaturated zone soil CFCs is a function of gas solubility in soil water and seasonal unsaturated zone temperatures. Using the increase in the SF₆ atmospheric mixing ratio, the apparent (piston flow) SF₆ age of the water varied seasonally between about 0 (modern) in January and up to 3 years in July–August. The SF₆ concentration and concentrations of dissolved solutes (SiO₂, Ca²⁺, Mg²⁺, Na⁺, Cl^?, and HCO₃ ^?) in spring discharge demonstrate a fraction of recent recharge following large precipitation events. The output of solutes in the discharge of springs minus the input from atmospheric deposition per hectare of watershed area (mol ha^?1 a^?1) were approximately twofold greater in watersheds draining the regolith of Catoctin metabasalts than that of granitic gneisses and granitoid crystalline rocks. The stable isotopic composition of water in spring discharge broadly correlates with the Oceanic Niño Index. Below normal precipitation and enriched stable isotopic composition were observed during El Niño years.     

Water soluble components of PM10 Chongqing, China

The concentrations of water soluble ions (Na⁺, NH₄ ⁺, K⁺, Mg²⁺, Ca²⁺, NO₃ ^-, Cl^-, and SO ₄ ^2- ) in PM₁₀ samples collected on cellulose filters by a medium-volume cascade impactor were determined, which were obtained from three kinds of areas in Chongqing: industrial area (Jiulongpo district), commercial and residential area (Jiangbei district) and background area (Jinyun Mountain in the Beibei district). The results showed that except for the background site, the annual average values of PM₁₀ are 23% – 61% higher than the national air quality standard (GradeII) (0.1 mg/m³), even that the value of the control site is still 20% higher than American standard (0.05 mg/m³). This implied that serious pollution of fine particles occurred in Chongqing. Nine kinds of soluble ions in water of PM₁₀ were analyzed by ion chromatography (IC) and the annual average concentrations follow the order of [SO ₄ ^2- ] > [NO³ _-] > [Cl^-] > [F^-], and [Ca²⁺] > [NH₄ ⁺] > [K⁺] > [Na⁺] > [Mg²⁺]. Their values were different in these areas: the industrial area > the commercial and living area > the control area. As for NH_{4 +}, K⁺, Ca²⁺, NO₃ ^- and SO ₄ ^2- , their seasonal average concentrations show a similar variation trend: the values in spring and fall were higher than those in summer and winter. The seasonal average concentrations of [Cl^-], [F^-], [Na⁺] and [Mg²⁺] are much lower than those of other ions. However, the concentrations of [Na⁺] changed more greatly in different seasons than those of the other three ions. Correlation coefficients showed that the three areas have been polluted by coal smoke and dust to different extents, while some local resources of pollution should be taken into consideration as well.     

Characterization of hydrogeochemical process and evaluation of water quality of seven geothermal springs,Bakreswar, India

A study was conducted in seven geothermal springs located in Bakreswar, District Birbhum, West Bengal, India, in order to assess numerous geochemical processes which were responsible for chemical composition of thermal and mineralized water. The study area lies over the Sone, Narmada, and Tapti lineament of Precambrian Chotanagpur Gneissic Complex. Water chemistry has been carried out based on reaction stoichiometry and geo-statistical tools to identify geochemical process. Piper and Gibbs diagram suggest that the spring water belongs to Ca²⁺-Mg²⁺-HCO₃^??+?CO₃^2? water type and are controlled by rock dominance. Dissolution and precipitation of calcite, dolomite, gypsum, and fluorite minerals were identified as principle source of major ions in seven geothermal spring water. Principle component analyses revealed that major ions of spring water are derived from geogenic processes such as weathering, dissolution, and precipitation of various minerals. Overall results suggest that major ions of the spring’s water are derived from natural origin because no evidence of anthropogenic sources was observed during the study period. This study has also revealed that water quality of spring’s water is not suitable for drinking purposes and quite suitable for irrigation because of high abundance of Na⁺, K⁺, Cl^?, and HCO₃^? ions.     

Hydrogeochemical characteristics of spring water in the Harz Mountains,Germany

Spring water samples of the Harz Mountains were taken in several seasons of 2010, 2011, and 2012. The samples have been analysed for main components (Na⁺, K⁺, Ca²⁺, Mg²⁺, SO₄²⁻, Cl⁻, HCO₃⁻ and NO₃⁻), trace elements (Fe, Cu, Pb, Zn, Y and REE), DOC, δ¹⁸O and δ²H of water. Meteoric water is indicated as the main source of the springs sampled. High precipitation rates lead to a dilution of the measured elemental concentrations. Furthermore, regional differences of rock and water interactions were found. REE concentrations and patterns of the spring waters vary between the distinct geological units and reflect the geochemical characteristics of the surrounding rocks. The actual data compared to measured data from the seventies and nineties of the last century indicate a decrease of the sulphate concentrations in the spring waters which is typical of many European mountain catchments.     

Growth patterns and implications of complex dendrites in calcite travertines from Lýsuhóll, Snæfellsnes, Iceland

Calcite dendrite crystals are important but poorly understood components of calcite travertine that forms around many hot springs. The Lýsuhóll hot-spring deposits, located in western Iceland, are formed primarily of siliceous sinters that were precipitated around numerous springs that are now inactive. Calcite travertine formed around the vent and on the discharge apron of one of the springs at the northern edge of the area. The travertine is formed largely of two types (I and II) of complex calcite dendrite crystals, up to 1 cm high, that grew through the gradual addition of trilete sub-crystals. The morphology of the dendrite crystals was controlled by flow direction and the competition for growth space with neighbouring crystals. Densely crowded dendrites with limited branching characterize the rimstone dams whereas widely spaced dendrites with open branching are found in the pools. Many dendrite bushes in the pools nucleated around plant stems. Growth of the dendrite crystals was seasonal and incremental. Calcite precipitation was driven by rapid CO₂ degassing of CO₂-rich spring waters during the spring and summer. During winter, when snow covered the ground and temperatures were low, opal-A precipitated on the exposed surfaces of the dendrites. Segmentation of dendrite branches by discontinuities coated with opal-A and overgrowth development around sub-crystals resulted from this seasonal growth cycle. The calcite dendrite crystals in the Lýsuhóll travertine differ in morphology from those at other hot springs, such as those at Lake Bogoria, Kenya, and Waikite in New Zealand. Comparison with the calcite dendrite crystals found at those sites shows that dendrite morphology is site-specific and probably controlled by carbonate saturation levels that, in turn, are controlled by the rate of CO₂ degassing and location in the spring outflow system.     

Carbon sources and signals through time in an Alpine groundwater Basin, Sagehen California

In 2003, chlorofluorocarbon (CFC) apparent ages, major ion chemistry and C isotopes were determined in nine springs from Sagehen Basin, a high elevation watershed in the eastern Sierra Nevada. Springs with similar apparent ages, which ranged between 15 and 45 a, had very similar chemistry despite being found in different areas of the watershed. In agreement with earlier studies, concentrations of rock-derived cations (Ca²⁺ and Na⁺), conductivity, temperature and pH increase with apparent age, documenting the chemical evolution of this groundwater system. In contrast with the cation data, δ¹³C and ΣCO₂ show no correlation with apparent age. δ¹³C displays a strong linear relationship with 1/ΣCO₂ (R² = 0.91). This is consistent with results from a previously developed soil respiration/diffusion model. Spring radiocarbon content ranged between 85 and 110 pmc and varied with apparent age, whereby the youngest groundwater has the highest radiocarbon values. The spring radiocarbon is set by the soil pCO₂ and its trend can be best described assuming the soil CO₂ is composed of a mixture of 50–66% fast- (15–25 a) and 33–50% slow- (4 ka) cycling components. These results are consistent with previous soil C studies. The C isotope data indicate that in Sagehen Basin the groundwater ΣCO₂ is inherited from the soil zone with little, if any, contribution from the dissolution of disseminated calcite.     

Chemical and isotopic characteristics of fluids along the Cameroon Volcanic Line, Cameroon

Results of the chemical and isotopic analysis of the water and gases discharged from volcanic crater lakes and soda springs located along the Cameroon Volcanic Line were used to characterize and infer their genetic relationships. Variations in the solute compositions of the waters indicate the dominant influence of silicate hydrolysis. Na⁺ (40–95%) constitutes the major cation in the springs while Fe²⁺ + Mg²⁺ (70%) dominate in the CO₂-rich lakes. The principal anion is HCO₃ (>90%), except in the coastal springs where Cl-predominates. Lakes Nyos and Monoun have FeMgCaHCO₃⁻ type signatures; the soda springs are essentially NaHCO₃⁻ type, while all other lakes show similar ionic compositions to dilute surface waters. Dissolved gases show essentially CO₂ (>90%), with small amounts of Ar and N₂, while CH₄ constitutes the principal component in the non-gassy lakes. Active volcanic gases are generally absent, except in the Lobe spring with detectable H₂S. Stable isotope ratio evidence indicates that the bicarbonate waters are essentially of meteoric origin. CO₂ (δ¹³C = −2 to −8%₀ and He (³He/⁴He = 1 to 5.6R_a) infer a mantle contribution to the total CO₂. CH₄ has a biogenic source, while Ar and N₂ are essentially atmospheric in origin, but mixing is quite common.     

Effects of nitrogen on the ecosystem respiration,CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions to the atmosphere from the freshwater marshes in northeast China

Freshwater marshes could be a source of greenhouse gases emission because they contain large amounts of soil carbon and nitrogen. These emissions are strongly influenced by exogenous nitrogen. We investigate the effects of exogenous nitrogen on ecosystem respiration (CO₂), CH₄ and N₂O emissions from freshwater marshes in situ in the Sanjiang Plain Northeast of China during the growing seasons of 2004 and 2005, using a field fertilizer experiment and the static opaque chamber/GC techniques. The results show that there were no significant differences in patterns of seasonal variations of CO₂ and CH₄ among the fertilizer and non-fertilizer treatments, but the seasonal patterns of N₂O emission were significantly influenced by the exogenous nitrogen. Seasonal averages of the CO₂ flux from non-fertilizer and fertilizer were 987.74 and 1,344.35 mg m ⁻² h ⁻¹, respectively, in 2004, and 898.59 and 2,154.17 mg m ⁻² h ⁻¹, respectively, in 2005. And the CH₄ from the control and fertilizer treatments were 6.05 and 13.56 mg m ⁻² h ⁻¹ and 0.72 and 1.88 mg m ⁻² h ⁻¹, respectively, in 2004 and 2005. The difference of N₂O flux between the fertilizer and non-fertilizer treatments is also significant either in 2004 and 2005. On the time scale of 20-, 100-, and 500-year periods, the integrated global warming potential (GWP) of CO₂ + CH₄ + N₂O released during the two growing seasons for the treatment of fertilizer was 97, 94 and 89%, respectively, higher than that for the control, which suggested that the nitrogen fertilizer can enhance the GWP of the CH₄ and N₂O either in long time or short time scale.     

Hydrogeochemical effects of secondary forest in Guangxi Nongla karst areas in China

Rainfall, throughfall, stemflow and spring were studied in a secondary forest during a wet season from April to August in 2006. Some of the chemicals in throughfall, stemflow and spring were increased in contrast with incident rainfall. Specifically, Cl⁻, HCO₃ ⁻, Na⁺ and Ca²⁺ were leached negatively in throughfall, but K⁺ and Mg²⁺ were leached positively. In stemflow, Cl⁻ and Na⁺ were leached negatively, the others were leached positively and their concentrations were higher than those in throughfall. Total carbon, organic carbon and inorganic carbon in throughfall and stemflow were increased as rainfall went through the secondary forest. The concentration of free CO₂ in rainfall was lower than both, throughfall and stemflow; the relationship between total acidity and free CO₂ was linear. pH of throughfall and stemflow , such as maximum, minimum and mean, were lower than that of rainfall and the extent of pH in spring was changed minimally. We came to a conclusion that rainfall via the secondary forest can lead to further erosion, accelerate the biogeochemical cycle in epikarst zone, enhance the effective state of alkali elements in the soil, supply vegetation with more nutrients and advance vegetation’s growth and succession, which are reasonably sufficient to form a stable karst ecosystem.     

Hydrochemical variations of epikarst springs in vertical climate zones: a case study in Jinfo Mountain National Nature Reserve of China

High temporal resolution (15 min) measurements of stage, pH, electric conductivity, temperature, and other hydrochemical parameters of groundwater at two sites in the Jinfo Mountain Nature Reserve of China were collected using automatic data loggers. Bitan Spring (BS 700 m a.s.l.) sits in subtropical climate zone, while Shuifang Spring (SS 2,060 m a.s.l.) is located in plateau temperate climate. The data show that hydrochemistry of epikarst springs at different altitudes is very sensitive to the changes of their physical environment, especially two factors: air temperature and soil CO₂ concentration. Springs at lower altitude are associated with higher air temperature and soil CO₂ concentration, thus more likely leading to more active karst processes than those at higher elevation. Water temperature and pH of BS showed a noticeable diurnal circle with high values in daytime and low values at night. The data also indicate that at least there are two effects that could impact the variations of groundwater hydrochemistry during flood pulse: dilution effect and CO₂ effect.     

The use of geochemical indicator elements in the exploration for hot water sources within geothermal fields

Soils, rocks, altered rocks, hot and cold waters, and hot spring precipitates were sampled within and on the outskirts of geothermal fields in China. The contents of thirty trace elements in soils and rocks show that Hg, As, Sb, Bi, Li, Rb, Cs, Au, Ag, B, W, Sn, Pb, Zn, Mn, Ni and Co can serve as direct and indirect indicators for geothermal field exploration. Large amounts of data indicate that Hg, As and Sb are the best indicators of hot water sources. Altered rocks contain higher Hg, As, Sb, Bi and Be than unaltered rocks. Based on their abundances in hot waters, it is suggested that the following elements may be used as hydrochemical indicators of high-temperature hot-water geothermal systems: K⁺, Na⁺, Ca²⁺, Mg²⁺, SO²⁻₄, HCO⁻₃, F⁻, Cl⁻, SiO₂, HBO₂, CO₂, pH, total dissolved solids and hydrochemical types, as well as Hg, As, Sb, Be, Li, Rb and Cs. Modern precipitates associated with hot springs have high contents of Ba, Be, Fe, Ti, Hg, As, Sb and Bi. Using these geochemical data, the authors have had much success in locating hot water drill sites within geothermal fields. Case histories are described for five geothermal areas.     

腾冲新生代火山区温泉CO2气体排放通量研究

近期研究表明,不仅火山喷发期会向当时的大气圈输送大量的温室气体,火山间歇期同样会释放大量的温室气体。在火山活动间歇期,火山区主要以喷气孔、温(热)泉以及土壤微渗漏等形式向大气圈释放温室气体。腾冲是我国重要的新生代火山区,同时也是重要的水热活动区,那里出露大量的温泉,然而目前未见腾冲火山区温泉气体排放通量的研究报道。本文利用数字皂膜通量仪测量了腾冲新生代火山区温泉中CO₂的排放通量。研究结果表明,腾冲新生代火山区温泉向当今大气圈输送的CO₂通量达3.58×10³ t·a^-1,相当于意大利锡耶纳Bassoleto地热区温泉中CO₂的排放规模。腾冲火山区温泉的CO₂释放通量主要受深部岩浆囊、断裂分布、地下水循环、围岩成分等多方面因素的影响。本文根据温泉中CO₂的排放特征,将腾冲温泉分为南北两区,南区温泉CO₂通量远高于北区的温泉,热海地热区的通量为腾冲CO₂通量的最大值。在北温泉区,CO₂通量主要受控于断裂的分布;而在南温泉区,除受到断裂控制外,热海地热区底部的岩浆囊及其与围岩的相互作用成为CO₂气体的重要物质来源,同时高温的岩浆囊为温泉及CO₂的形成提供了重要热源。     

Hydrogeology of northern Sierra de Chiapas,Mexico: a conceptual model based on a geochemical characterization of sulfide-rich karst brackish springs

Conspicuous sulfide-rich karst springs flow from Cretaceous carbonates in northern Sierra de Chiapas, Mexico. This is a geologically complex, tropical karst area. The physical, geologic, hydrologic and chemical attributes of these springs were determined and integrated into a conceptual hydrogeologic model. A meteoric source and a recharge elevation below 1,500 m are estimated from the spring-water isotopic signature regardless of their chemical composition. Brackish spring water flows at a maximum depth of 2,000 m, as inferred from similar chemical attributes to the produced water from a nearby oil well. Oil reservoirs may be found at depths below 2,000 m. Three subsurface environments or aquifers are identified based on the B, Li⁺, K⁺ and SiO₂ concentrations, spring water temperatures, and CO₂ pressures. There is mixing between these aquifers. The aquifer designated Local is shallow and contains potable water vulnerable to pollution. The aquifer named Northern receives some brackish produced water. The composition of the Southern aquifer is influenced by halite dissolution enhanced at fault detachment surfaces. Epigenic speleogenesis is associated with the Local springs. In contrast, hypogenic speleogenesis is associated with the brackish sulfidic springs from the Northern and the Southern environments.     

Hydrochemical and isotope characteristics of spring water and travertine in the Baishuitai area (SW China) and their meaning for paleoenvironmental reconstruction

A method of combining hydrochemical data logging and in situ titrating with measurement of stable carbon and oxygen isotopes was used to reveal the hydrochemical and isotopic characteristics in the Baishuitai travertine scenic area of SW China. It was found that the travertine-forming springs have a very high concentration of calcium and bicarbonate, and accordingly very high CO₂ partial pressures, which are not likely to be produced by biological activity in soil alone. Further analysis of the stable carbon isotopes of the springs shows that the high pressure of CO₂ is mainly related to an endogenic CO₂ source. That means the Baishuitai travertine is endogenic in origin. This is contrast to the commonly accepted saying that the travertine deposition in this study simply is a product of warm and humid conditions in a karst ecological environment. Rapid CO₂ degassing from the water is triggered by the much higher partial pressures in water than that of the surrounding air. Consequently, as the waters flow downstream of the spring the pH increases, the waters become supersaturated with respect to calcite, and travertine is deposited. The preferential release of ¹²CO₂ to the atmosphere results in a progressive increase of travertine ¹³C downstream. This is concluded with a preliminary discussion of variation in travertine-forming water temperatures, according to differences in stable oxygen isotopic compositions of the travertine formed in different epochs at Baishuitai. It was found that the change in water temperature is as high as 13 °C, i.e., from 23 °C at about 2500 years b.p., to 10 °C at present. This may mainly reflect that the effect of geothermal source on water temperature is decreasing. The problems involved in paleoenvironmental reconstruction with endogene travertine are also discussed. They are the impacts of "dead carbon" in radiocarbon dating and the enrichment in ¹³C of travertine by endogenic CO₂ and degassing of CO₂ from water, which has to be considered in paleovegetation reconstruction when using ¹³C data of the endogene carbonate deposits.     

西安灞河流域现代岩溶作用与CO2吸收量

本文探讨了灞河流域岩溶特征、CO²估算方法和CO²吸收量。观测资料表明,灞河流 域河水中ｐＨ值在冬春季高,夏秋季低,而ＨＣＯ３含量通常与ｐＨ相反。河水和黄土地下水中 ｐＨ值、ＨＣＯ３等化学成分含量与北方南部石灰岩区岩溶水基本相同,表明该区现代岩溶作用 明显,黄土地层也在不断吸收CO²,并对全球碳循环有重要影响。雨水富含CO²,其中约有 ８２％的CO²被岩溶过程吸收,１８％左右的随河水流失。根据一个流域CO²输入量和输出量,可 以计算岩溶过程中 CO²吸收量。计算表明,灞河流域现代岩溶过程中每年吸收的 CO²约为５６３２．８ｔ。