Study of solute sources and evolution of hydrogeochemical processes of the Chhota Shigri Glacier meltwaters,Himachal Himalaya,India

Abstract

This study was carried out from 2003 to 2007 to understand the hydrogeochemical processes and the solute sources of the meltwaters of the Chhota Shigri Glacier, Himalaya. The meltwater is almost neutral to slightly alkaline in nature: bicarbonate and sulphate are the dominant anions, while calcium and magnesium are the dominant cations. Bicarbonate is found to be derived from carbonate weathering and partly from silicate weathering. Rock weathering followed by precipitation are the main controlling factors that influence the meltwater chemistry of this region. The relatively high values of pCO₂ reflect a higher rate of solubility in comparison to release of excess CO₂ gas to the atmosphere. The presence of active hydrogeochemical processes and sediment–water interaction results in excess solute transport through the meltwater to the Chandra River that feeds the Chenab, one of the great Himalayan river systems, and ultimately flows into the ocean. This study is the first of its kind to understand in detail the hydrogeochemical process and resultant solute load transport in this Himalayan glacier.

Citation Sharma, P., Ramanathan, A.L., and Pottakkal, J., 2013. Study of solute sources and evolution of hydrogeochemical processes of the Chhota Shigri Glacier meltwaters, Himachal Himalaya, India. Hydrological Sciences Journal, 58 (5), 1128–1143.

Editor Z.W. Kundzewicz     

Effects of climate and land-use change on green-water variations in the Middle Yellow River,China

Abstract

Water resources management should cover both blue water and green water. For green-water management at the river drainage basin scale, the green-water coefficient (C _gw) is adopted, defined as the ratio of annual green water to annual precipitation. Based on data from the Middle Yellow River basin, China, for the period 1950 to 2007, we studied the temporal variation in C _gw in response to some influencing factors. A decreasing trend in C _gw was found. The influence of changes in land management on C _gw, reflected by an increase in the area (A _sw) of soil and water conservation measures, is emphasized. Using multiple regression analysis, the contributions of A _sw and the 5-year moving averages of annual precipitation and air temperature were estimated as 51, 37 and 12%, respectively. The results may provide useful information for better management of water resources, including green and blue water flows in the Yellow River basin.

Editor Z.W. Kundzewicz; Associate editor D. Gerten

Citation Xu, J.-X., 2013. Effects of climate and land-use change on green-water variations in the Middle Yellow River, China. Hydrological Sciences Journal, 58 (1), 1–12.     

Paleomagnetic result of the Lower-Cretaceous from Luanping basin,Hebei Province and its tectonic implications*

A paleomagnetic study of about 95 samples from 16 sites sampled in the Early Cretaceous in Luanping basin in Hebei Province was reported. Stepwise thermal demagnetization was used to isolate magnetic components. Most samples have a characteristic direction with a high temperature component above 500°C. The tectonic-corrected data areD = 347.8°,I = 50.4°, α₉₅ = 7.l°, and the corresponding pole position is at 76.1°N, 346.3°E,with dp =6.4°,dm = 3.8°, paleolatitude λ = 31.1°N. This result indicates a counterclockwise post-Cretaceous rotation of 30.7° ±9.8° with respect to the stable Ordos basin in the west of North China Block, and a non-significant northward motion. This rotation could be related to local fault action or structural detachment, or regional NNW-NWWward motion and collision of Kula-Pacific plate with eastern China since the Early Cretaceous.

     

RATIO METHOD FOR DETERMINING CHARACTERISTICS OF IDEAL,LEAKY AND BOUNDED AQUIFERS

ABSTRACT

A Ratio Method is presented, which dispenses with the classical curve-matching procedure for computing characteristics of Ideal, Leaky and Bounded aquifers. This simple method consists of selecting any three values of observed drawdown, (t₀, s₀), (t₁, s₁) and (t₂, S₂), such that t₁ = 2 t₀ and t₂ = 100 t₀. Then, using the ratios, s_{0/s 1} and s₀/s₂, the values of u₀, W_(u0) as well as r/B (in the case of leaky aquifers) and r_i (in the case of aquifers with one boundary) are extrapolated from the charts presented. The extrapolated values are substituted in the standard equations to determine the aquifer characteristics. The Ratio Method may also have useful application in other branches of science where the curve-matching procedure is employed for calculation of parameters. (Key Words: Ratio Method; Aquifer characteristics; Ideal aquifer; Leaky aquifer; Bounded aquifer)     

On the magnetic flux linkage of an electrically-conducting fluid

Abstract

A method has recently been proposed for finding the radius r_c of the electrically-conducting fluid core of a planet of outer radius r_s from observations of the magnetic field B in the accessible region near or well above the surface of the planet (Hide, 1978). The method is based on the supposition that when the magnetic field is produced by hydromagnetic dynamo action in the core, implying that the magnetic Reynolds number R there is large, (a) fluctuations in B can occur everywhere on the comparatively short advective time-scale τ _A associated with fluid motions in the core and so can fluctuations in the quantity N, defined for any closed surface S as the total number of intersection of magnetic lines of force with S, provided that S lies well outside the core, but (b) at the surface of the core, where lines of magnetic force emerge from their region of origin, concomitant fluctuations in N are negligibly small, of the order of τ _A/τ_O where τ _O (= Rτ_A ) is the Ohmic decay time of the core.

A proof of this supposition follows directly from the general expression derived in the present paper showing that when S is a material surface the time rate of change of N is equal to minus twice the line integral of the current density divided by the electrical conductivity around all the lines on S where the magnetic field is tangential to S. This expression (which Palmer in an accompanying paper rederives and extends to the relativistic case using the mathematical formalism of Cartan’s exterior calculus) also provides a direct demonstration of the well-known result that although high electrical conductivity, sufficient to make R ? 1, is a necessary condition for hydromagnetic dynamo action, such action is impossible in a perfect conductor, when R→ ∞.     

Note on the scalar dynamo model

Abstract

Bayly (1993) introduced and investigated the equation (? _t + v·▽-η ▽²)S = RS as a scalar analogue of the magnetic induction equation. Here, S(r, t) is a scalar function and the flow field v(r, t) and “stretching” function R(r, t) are given independently. This equation is much easier to handle than the corresponding vector equation and, although not of much relevance to the (vector) kinematic dynamo problem, it helps to study some features of the fast dynamo problem. In this note the scalar equation is considered for linear flow and a harmonic potential as stretching function. The steady equation separates into one-dimensional equations, which can be completely solved and therefore allow one to monitor the behaviour of the spectrum in the limit of vanishing diffusivity. For more general homogeneous flows a scaling argument is given which ensures fast dynamo action for certain powers of the harmonic potential. Our results stress the singular behaviour of eigenfunctions in the limit of vanishing diffusivity and the importance of stagnation points in the flow for fast dynamo action.     

Decreasing trend of sediment transfer function of the Upper Yellow River,China, in response to human activity and climate change

Abstract

An index (F_s) for sediment transfer function is introduced, based on the sediment budget at the channel scale. The purpose of this study is two-fold: to gain a deeper insight into how F_s is influenced by natural and human factors, and to provide some new knowledge for decision making in the management of the Upper Yellow River, China. Since 1960, the F_s of the Lanzhou to Toudaoguai reach of the Upper Yellow River shows a decreasing trend. At the drainage basin level, the decreased F_s can be explained by changes in precipitation and air temperature, as well as by a number of variables describing human activity, such as reservoir regulation, water diversion, and soil and water conservation. The higher temperature reduces the transfer function, while the larger runoff coefficient increases it. At the channel level, the decreased F_s can be explained by a number of variables of flow and sediment input. Three countermeasures for restoration of the F_s are suggested.

Editor Z.W. Kundzewicz     

A robust empirical model to estimate earthquake-induced excess pore water pressure in saturated and non-saturated soils

In engineering practice, the liquefaction potential of a sandy soil is usually evaluated with a semi-empirical, stress-based approach computing a factor of safety in free field conditions, defined as the ratio between the liquefaction resistance (capacity) and the seismic demand. By so doing, an estimate of liquefaction potential is obtained, but nothing is known on the pore pressure increments (often expressed in the form of normalized pore pressure ratio r_u) generated by the seismic action when the safety factor is higher than 1. Even though r_u can be estimated using complex numerical analyses, it would be extremely useful to have a simplified procedure to estimate them consistent with the stress-based approach adopted to check the safety conditions. This paper proposes such a procedure with reference to both saturated and unsaturated soils, considering the latter as soils for which partial saturation has been artificially generated with some ground improvement technology to increase cyclic strength and thus tackle liquefaction risk. A simple relationship between the liquefaction free field safety factor FS, and r_u(S_r) is introduced, that generalizes a previous expression proposed by Chiaradonna and Flora (Geotech Lett, 2020. https://doi.org/10.1680/jgele.19.00032) for saturated soils. The new procedure has been successfully verified against some experimental data, coming from laboratory constant amplitude cyclic tests and from centrifuge tests with irregular acceleration time histories for soils having different gradings and densities.

     

Preparation and evaluation of polyaluminum chloride sulfate (PACS) as a coagulant to remove natural organic matter from water

A series of polyaluminum chloride sulfate (PACS) coagulants, which have different SO₄^2–/Al³⁺ and OH/Al (γ) mole ratio, has been successfully developed using AlCl₃·6H₂O, Al₂(SO₄)₃·18H₂O and Na₂CO₃ as raw materials. The coagulation performance of PACS for removing natural organic matter (NOM) from surface water was evaluated, and the effect of SO₄^2–/Al³⁺ mole ratio and γ value in coagulants PACS on DOC and UV₂₅₄ removal was determined. Furthermore, the influence of pH and dosage of the selected PACS with a SO₄^2–/Al³⁺ ratio of 0.0664 and a γ value of 2.0, which achieved the best coagulation performance for the removal of DOC and UV₂₅₄ of all PACS coagulants, on the removal of DOC and UV₂₅₄ and residual aluminum concentration in treated water was investigated. The results were compared with the ones of polyaluminum chloride (PAC) with γ value of 2.0. The experimental data show that the performance of PACS as a coagulant was highly dependent on SO₄^2–/Al³⁺ mole ratio and γ value. Both for the selected PACS and for PAC, the best DOC and UV₂₅₄ removal results were obtained in the range of pH from 5.0 to 8.2 and at the coagulation dose of 5.0 mg/L as Al. Under the optimum coagulation conditions, the selected PACS gave higher DOC and UV₂₅₄ removal efficiencies, and lower residual aluminum concentrations in the treated water than PAC. The maximum removal of DOC and UV₂₅₄ for PACS was approximately 88.0% and 93.0%, respectively. At the optimum coagulant dose and pH 6.5, the concentration of residual aluminum in treated water by both selected PACS and PAC can comply with the regulated limits. The major mechanisms of NOM removal by PACS and PAC coagulation involve complexation‐charge‐neutralization‐precipitation.     

Genetic features of gas-condensate reservoirs in the Kekeya Field,southwest depression in the Tarim Basin,China

Oils, condensates and natural gases in the Kekeya Field, southeast depression of the Tarim Basin were studied for their geochemical characteristics. According to the distribution analysis of the C₂/C₃ values with C₁/C₂ values, C₂/C₃ values with C₁/C₃ values, as well as C₂/C₃ values with dryness index, there are two different types of natural gases in the studied field, which are spatially regularly distributed. One is the oil cracking gas, located on shallow reservoirs over X ²₅ reservoir, namely Upper oil legs; the other is kerogen cracking gas, located on X ²₇ reservoirs, X₈ reservoirs and E₂ k reservoirs, namely Lower oil legs. In addition, the distribution patterns of molar concentration of oils and condensates with different carbon numbers of the n-alkanes in the Kekeya Field indicate that the crude oils have experienced several kinds of secondary alterations, which were closely related to the charging of gaseous hydrocarbons after petroleum accumulation. These results indicate that, based on the research of δ ¹³C values of individual hydrocarbons, heptane values and isoheptane values of light hydrocarbons and aromatic maturity parameters for oils, condensates and natural gases, oils and gases were charged at different geological time in the Kekeya Field.

     

Application of the water table fluctuation method to characterize groundwater recharge in the Pampa plain,Argentina

Abstract

The water table fluctuation (WTF) method is based on accepting that rises of a water table are due to recharge water reaching the groundwater. To apply the method, an estimate of the specific yield of the zone of fluctuation of the groundwater level is required. In this paper, a method for estimation of the specific yield (S_y) is proposed; it consists of a graphical procedure which relates rises in groundwater level to the precipitation from which they originated. The method presents more reliable S_y values as the number of events measured increases. Eighteen years of daily measurements were analysed to obtain a S_y value of 0.09, which was used to apply the WTF method. The obtained recharge values show consistency with values calculated by other authors for the same region.

Editor D. Koutsoyiannis

Citation Varni, M., Comas, R., Weinzettel, P., and Dietrich, S., 2013. Application of water table fluctuation method to characterize the groundwater recharge in the Pampa plain, Argentina. Hydrological Sciences Journal, 58 (7), 1445–1455.     

The Chemical Species Distribution of Aluminum in Composite Flocculants Prepared from Polyaluminum Chloride (PAC) and Polydimethyldiallylammonium Chloride (PDMDAAC)

In order to improve the coagulation/flocculation efficiency of polyaluminum chloride (PAC), a composite flocculant of PAC and polydimethyldiallylammonium chloride (PDMDAAC), or PAC‐PDMDAAC, was prepared. The chemical species distribution of aluminum in PAC and PAC‐PDMDAAC, which has a close relationship with their coagulation/flocculation performance, was investigated by Al‐Ferron complexation timed spectrophotometry and ²⁷Al‐NMR. The factors affecting the chemical species of aluminum in PAC‐PDMDAAC, such as the weight concentration of PDMDAAC (Wp), basicity (B) of PAC, and viscosity (η) of PDMDAAC, were studied. The flocculation efficiencies of PAC‐PDMDAAC, PAC and PDMDAAC were studied on a six‐spindle multiple stirrer unit. The results showed that the aluminum species distribution in PAC‐PDMDAAC depends on the Wp, B and η value. When the B value is 1.5 and η value is 1.22 dL/g, the composite flocculant with Wp = 15 % gives highest Al_b and Al₁₃ contents, and its flocculation efficiency is highest in the test flocculations.     

Evaluation of chemical composition changes of surface water in Boguchan Reservoir (Siberia,Russia)

Abstract

Mathematical transformation models of TDS (total dissolved salts) and organic substance concentration as BOD₅ (biochemical oxygen demand) in water of the Angara River and the proposed Boguchan Reservoir have been developed. Having filled the reservoir to a water level of 208 m, in an average year it is shown that increase in surface water mineralization is expected in the cross-section of Boguchan Hydroelectric Power Station giving TDS of up to 20–40 mg/dm³, and values of BOD₅ will increase to 2.0–3.9 mgO₂/dm³. In a low-water year the value of BOD₅ may be as great as 5 mgO₂/dm³; mineralization, in contrast, decreases. Several years after reservoir filling, the values of BOD₅ would decrease, but water quality of the upper part of the reservoir would still depend on the degree of treatment of wastewater discharged to it.

Editor D. Koutsoyiannis

Citation Savichev, O.G. and Matveenko, I.A., 2013. Evaluation of chemical composition changes of surface water in Boguchan Reservoir (Siberia, Russia). Hydrological Sciences Journal, 58 (3), 706–715.     

Intersector disbalance of the large-scale open solar magnetic field fluxes,active and passive boundaries,and solar-terrestrial extrastorms

The dynamics (from rotation to rotation) of the absolute values of the large-scale open solar magnetic field fluxes in the four-sector field structure has been considered for the first time, using CRs 2032–2035 in July–October 2005 as examples. An important role of the ratio of the fluxes at the eastern and western sector boundaries (Φ _E /Φ _W ) is confirmed. As in the cases of the two-sector structure, Φ _E /Φ _W > 1 is typical of active rigidly corotating boundaries with intense sunspot formation, flares, and interplanetary and geomagnetic disturbances. A remarkable property of the considered structure was the presence of a rapidly increasing flux in an initially narrow sector and the flux interaction with a stable rigidly corotating sector in the zone of the main active longitudes, which caused an unexpectedly strong geoeffective long-range action of flares near the corresponding active boundary.     

Seasonal and annual variation of CO2 flux above a broad-leaved Korean pine mixed forest

Long-term measurement of carbon metabolism of old-growth forests is critical to predict their behaviors and to reduce the uncertainties of carbon accounting under changing climate. Eddy covariance technology was applied to investigate the long-term carbon exchange over a 200 year-old Chinese broad-leaved Korean pine mixed forest in the Changbai Mountains (128°28′E and 42°24′N, Jilin Province, P. R. China) since August 2002. On the data obtained with open-path eddy covariance system and CO₂ profile measurement system from Jan. 2003 to Dec. 2004, this paper reports (i) annual and seasonal variation of F _NEE, F _GPP and R _E; (ii) regulation of environmental factors on phase and amplitude of ecosystem CO₂ uptake and release Corrections due to storage and friction velocity were applied to the eddy carbon flux.

L_AI and soil temperature determined the seasonal and annual dynamics of F_GPP and R_E separately. V_PD and air temperature regulated ecosystem photosynthesis at finer scales in growing seasons. Water condition at the root zone exerted a significant influence on ecosystem maintenance carbon metabolism of this forest in winter.

The forest was a net sink of atmospheric CO₂ and sequestered −449 g C·m⁻² during the study period; −278 and −171 gC·m⁻² for 2003 and 2004 respectively. F _GPP and F _RE over 2003 and 2004 were −1332, −1294 g C·m⁻². and 1054, 1124 g C·m⁻² respectively. This study shows that old-growth forest can be a strong net carbon sink of atmospheric CO₂.

There was significant seasonal and annual variation in carbon metabolism. In winter, there was weak photosynthesis while the ecosystem emitted CO₂. Carbon exchanges were active in spring and fall but contributed little to carbon sequestration on an annual scale. The summer is the most significant season as far as ecosystem carbon balance is concerned. The 90 days of summer contributed 66.9, 68.9% of F _GPP, and 60.4, 62.1% of R _E of the entire year.

     

The impact of the spatial variability in bottom roughness on tidal dynamics and energetics,a case study: the M 2 surface tide in the North European Basin

A modified version of the 3D finite-element hydrostatic model QUODDY-4 is used to quantify the changes in the dynamics and energetics of the M ₂ surface tide in the North European Basin, induced by the spatial variability in bottom roughness. This version differs from the original one, as it introduces a module providing evaluation of the drag coefficient in the bottom boundary layer (BBL) and by accounting for the equilibrium tide. The drag coefficient is found from the resistance laws for an oscillatory rotating turbulent BBL over hydrodynamically rough and incompletely rough underlying surfaces, describing how the wave friction factor as well as other resistance characteristics depend on the dimensionless similarity parameters for the BBL. It is shown that the influence of the spatial variability in bottom roughness is responsible for some specific changes in the tidal amplitudes, phases, and the maximum tidal velocities. These changes are within the model noise, while the changes in the averaged (over a tidal cycle) horizontal wave transport and the averaged dissipation of barotropic tidal energy may be of the same orders of magnitude as are the above energetic characteristics as such. Thus, contrary to present views, ignoring the spatial variability in bottom roughness at least in the North European Basin is only partially correct: it is valid for the tidal dynamics, but is liable to break down for the tidal energetics.

     

Characteristics,genesis and accumulation history of natural gas in Hetianhe gasfield,Tarim Basin,China

Hetianhe gasfield in Bachu region of the Tarim Basin is mainly composed of three reservoir-caprock assembly, namely regional caprock of upper mudstone, middle mudstone and lower mudstone of the Carboniferous and reservoir of Bachu bioclastic limestone, glutenite and the Ordovician carbonate buried hill. Natural gas in Hetianhe gasfield sourced from the Cambrian source rock. It is thought that gases in Ma4 well block in the east of Hetianhe gasfield are mainly crude-oil cracked gases, while those in Ma3 and Ma8 well blocks in the west are the mixture gases of kerogen cracked gases and crude-oil cracked gases. Natural gas is rich in H₂S and accumulated in multiply stages as the result of TSR. The accumulation history is divided into three stages, namely accumulation and breakage in the late Caledonian-early Hercynian, migration and dissipation in the late Hercynian and accumulation in Himalayan. The main accumulation of reformed gas reservoir is in Himalayan.

     

引水工程絮凝剂余铝对杭州西湖水体、底泥铝盐分布的影响

通过对杭州西湖综合保护工程钱塘江引水范围内多个湖区水体和底泥中铝盐含量的调查分析,研究了工程絮凝剂余铝对西湖水体、底泥铝盐及沉水植物附着物的影响.结果表明:(1)引水工程输入的絮凝剂残余铝盐导致各湖区入水口水中铝离子含量普遍高于湖心,高出7.86%~288.55%不等,但底泥中Al_2O_3含量在整个湖区分布较为均匀;(2)约0.04~0.20 m/s流速下,沉水植物很容易成为残余铝盐絮凝物的附着受体;(3)秋、冬季水体中铝离子浓度较高,对西湖水生生物存在更大的生物潜在危害,有必要重视秋、冬季的沉水植物恢复工作.引水工程对西湖水体的影响是长久且难以预见的,在引水的同时应尽量减少其负面影响,可减少絮凝剂的使用或选择环保型絮凝剂,并选择合适的水生植物.     

The hydrothermal karstification and its effect on Ordovician carbonate reservoir in Tazhong uplift of Tarim Basin,Northwest China

With a detailed study on petrology, mineralogy and geochemistry of some important Ordovician carbonate well core samples in Tazhong uplift of Tarim Basin, the distinguishing symbols of hydrothermal karstification are first put forward as the phenomena of rock hot depigmentation, hot cataclasm and the appearance of typical hydrothermal minerals such as fluorite, barite, pyrite, quartz and sphalerite. The main homogenization temperatures of primary fluid inclusions in fluorite are from 260 to 310°C, indicating the temperature of hydrothermal fluid. The fluid affected the dissolved rocks and showed typical geochemistry features with low contents of Na and Mg, and high contents of Fe, Mn and Si. The ratio of ³He/⁴He is 0.02R _a, indicating the fluid from the typical continental crust. The hydrothermal fluid karstification pattern may be described as follows: the hot fluid is from the Permian magma, containing dissolving ingredients of CO₂ and H₂S, and shifts along fault, ruptures and unconformity, and dissolves the surrounding carbonates while it flows. The mechanism of hydrothermal karstification is that the mixture of two or more fluids, which have different ion intensity and pH values, becomes a new unsaturated fluid to carbonates. The hydrothermal karstification is an important process to form hypo-dissolved pinholes in Ordovician carbonates of Tazhong uplift of Tarim Basin, and the forming of hydrothermal minerals also has favorable influence on carbonate reservoirs.

     

Climate impacts on global irrigation requirements under 19 GCMs,simulated with a vegetation and hydrology model

Abstract

This study quantifies global changes in irrigation requirements for areas presently equipped for irrigation of major crop types, using climate projections from 19 GCMs up to the 2080s. Analysis is based on results from the global eco-hydrological model LPJmL that simulates the complex and dynamic interplay of direct and indirect climate change effects upon irrigation requirements. We find a decrease in global irrigation demand by ～17% in the ensemble median, due to a combination of beneficial CO₂ effects on plants, shorter growing periods and regional precipitation increases. In contrast, increases of >20% are projected with a high likelihood (i.e. in more than two thirds of the climate change scenarios) for some regions, including southern Europe, and, with a lower likelihood, for parts of Asia and North America as well. If CO₂ effects were not accounted for, however, global irrigation demand would hardly change, and increases would prevail in most regions except for southern Asia (where higher precipitation is projected). We stress that the CO₂ effects may not be realized everywhere, that irrigation requirements will probably increase further due to growing global food demand (not considered here), and that a significant amount of water to meet future irrigation requirements will have to be taken from fossil groundwater, environmental flow reserves or diverted rivers.

Editor D. Koutsoyiannis; Associate editor A. Montanari

Citation Konzmann, M., Gerten, D., and Heinke, J., 2013. Climate impacts on global irrigation requirements under 19 GCMs, simulated with a vegetation and hydrology model. Hydrological Sciences Journal, 58 (1), 1–18.