Fresh Salt Water Research Articles

Steam-flaked lupins for preruminant calf rations

Steam-rolled lupins were studied as a cheaper alternative to complex and expensive commercial calf rations for rearing dairy calves. Four diets were fed to 4 groups of 6-8 calves: diet 1, 100% commercial pelletted calf ration (CR), 0% steam-flaked lupins (SFL); diet 2, 67% CR, 33% SFL; diet 3, 33% CR, 67% SFL; and diet 4, 100% SFL. A multimineral salt block and fresh water were available. Calves received milk-replacer (MR) in week 1, MR plus experimental diets in weeks 2-5, then experimental diets plus a small amount of straw in weeks 6-10. Calves grazed fresh pasture in weeks 11-15. Blood and rurnen contents were sampled in weeks 2 (blood only) 4,6 (diets 1-4), 8 and 10 (diets 1-3). In weeks 2-5, calves fed diet 4 ate less than calves fed diets 1, 2 and 3 (SFL 0.38 v. 0.50 kg dry matter (DM)/day, MR 0.47 v. 0.49 kg DM/day; P<0.05), grew less rapidly (0.58 v. 0.66 kg/day, not significant) and lost appetite in weeks 5-7. Feeding diet 4 was abandoned and CR, barley and hay were fed in weeks 8-10. In weeks 6-10, calves ate 2.49 kg DM/day of diets 1, 2 and 3 and grew 0.99 kg/day. Growth rates did not differ, at 0.59 kg/day in weeks 11-15; thus calves fed diet 4 seem to have sustained no permanent injury. Plasma glucose was higher in calves fed diet 4 in week 6 (P<0.05) but otherwise did not differ between diets or ages. Ruminal volatile fatty acids differed between diets only in week 6, when diet 4 resulted in a lower concentration than diets 1, 2 and 3 (95 v. 118 mmol/L), with 54.6 v. 49.9% acetic, 31.0 v. 34.1% propionic, and 8.0 v. 10.7% butyric acids. Plasma acetate increased steadily from 0.23 mmol/L at week 2 to 0.58 mmol/L at week 10 (P<0.05), with no difference between diets. We conclude that SFL can be a satisfactory component of the diet of young calves at up to 67% of the ration, producing calves with sufficiently developed ruminal digestion to permit unsupplemented grazing after 10 weeks of feeding.

Shaly-Sand Log Analysis in an Environmental Application: ABSTRACT

Abstract A procedure to determine ground-water quality from analysis of electromagnetic induction logs was developed to detect and assess the distribution of saltwater intrusion into the alluvial Great Bend Prairie aquifer. The cross correlation between the induction and natural gamma-ray logs from a freshwater well was optimized (based on empirical statistics) to reduce shaly-sand effects — the variations on the induction log due primarily to the presence of clay minerals. The correction method obviates determination of variations of aquifer porosity or cation-exchange capacity for detailed log analysis of porewater conductance. The method was applied to sets of logs collected from a network of monitoring wells in the aquifer. The corrected induction logs (units of mS/m) were calibrated to chloride concentration (mg/L) based on a highly significant linear-regression relationship (R=0.99) between the chlorinity of well-water samples and the median values of the corrected log for the screened intervals of the wells sampled. The derived freshwater-saltwater transition zone profiles were processed by curve-fitting techniques to develop objective, quantitative estimates of key characteristics such as the saturated thicknesses of the usably fresh and unusable salt water (at the 500 mg/L chloride interface) and the determination of aquifer dispersivity. The curve-fit method also allowed incomplete transition zone profiles to be completed to the base of the aquifer by extrapolation. The transition zone characteristics provide a database for regionalization of saltwater distribution and for monitoring changes of the distribution at both local and regional scales.

On a doubly degenerate equation arising in fresh-salt water flow with pumping

On a doubly degenerate equation arising in fresh-salt water flow with pumping

The modell ing study of flow in Vasishta Godavari estuary

The v as islua branch of the Godavari estuary open s into the Bay of Bengal at Antarvedi,Conditions in the estuary arccharacterized by a seasonally varying fresh water discharge and salt water intrusionfrom the Bay resul tingfrom the flow as~oc ia ted with the se.ni- diu rnal t ide. A numerica l model is applied to simulatethe flow and sali nity structures which have also been documented m the literature. The observations duringmonsoon and post-monsoon seasons arc used in a comparison with the theor etical results which are derived froma model in which turbulenceclosure scheme is used.

An Integrated BEM Algorithm for Transient 2-D Flow in Unconfined Aquifers

: A new algorithm based on a time stepping BEM formulation for problems of transient or steadystate 2-D groundwater flow is discussed. Of particular interest is the location of moving boundaries, such as the free surface in unconfined groundwater flow and/or the fresh-salt water interface in coastal aquifers. A variety of transient external forcing functions, e.g., rainfall, tidal effects, etc., or combinations of the above, are considered. Numerical results from two example problems demonstrate the versatility and accuracy of the proposed methodology.

Impacts of future sea level rise on salt water intrusion in the Changjiang River Estuary

Sea level rise could increase the salinity of an estuary by altering the balance between fresh water and salt water. The implications of sea level rise for increasing salinity have been examined in the Changjiang (Yangtze) River estuary. By correlative analysis of chlorinity, discharge and tidal level and calculation of two-dimensional chlorinity, distribution of the Changjiang River estuary, the changes of the intensity and lasting hours of salt water intrusion at Wusong Station and the changes of chlorinity distribution in the South Branch of the Changjiang River estuary have been estimated when future sea level rises 50–100 cm. The intensity of salt water intrusion in the future will be far more serious than current trend.

On forced internal waves in a rectangular trench

The generation of internal waves in a submarine rectangular trench by normally incident surface waves has been investigated through laboratory experiments and theory. A linear model was developed for small-amplitude, simple harmonic wave motions. In this model, the fluid outside the trench is homogeneous, and the fluid in the trench is composed of two homogeneous layers of different densities separated by a transition region of linear density variation; viscous dissipation is treated based on the assumption of a laminar boundary layer. In the experiments, the stratification in the trench was created using fresh water and salt water, and a scanning laser beam and detector system was used to measure the amplitude of internal waves. The study shows that, when the frequency of the surface waves corresponds to the natural frequency of internal waves, the amplitude of internal waves becomes large compared to the amplitude of surface waves. The natural frequency of oscillation of internal waves decreases as the thickness of the density interface increases and the depth of the lower fluid decreases. Two distinct classes of internal waves were observed, namely, standing internal waves when the lower fluid was deep, and travelling internal waves when the lower fluid was shallow. The linear model predicted the response curve for internal waves quite well in all the cases investigated. It was also found that the internal waves were strongly damped when the depth of the lower fluid was small compared to the wavelength of internal waves.

Estimation of Transverse Dispersivity Based on the Measured Concentration in a Borehole and Numerical Simulation

This paper presents a method for the estimetion of transverse dispersivity in a homogeneous isotropic coastal aquifer where salt water intrusion takes place and the mixing zone of fresh-salt water is observed. An approximate solution of the concentration profile on the axis perpendicular to the fresh-salt water interface is derived from a similarity approach and compared with the concentration profile measured in a filed experiment. A two-dimensional numerical simulation on salt water intrusion and dispersion is performed using the dispersivities estimeted by the proposed method. Numerically predicted concentration profiles agree well with the experimental data.

Influence of Pumps on Salinity of a Coastal Aquifer with Legal Protection (A Zone in the North of Isla Cristina, Huelva, Spain)

In this article we show that the legal measures for protection of aquifers are not enough to lessen the pumping if the users are not associated and determined to have a rational distribution of water. The expansive agriculture on the North side of Isla Cristina (Huelva, Spain), based on citrus and strawberry growing, uses high volumes of groundwater that comes from a tertiary age detritic coastal aquifer with a significant lack of resources. This causes a decrease of the residual flow to the sea, deep pumpcones, and an inversion of the hydraulic gradient, which initiates the progressive salinization of the aquifer northwards, in the sense that the fresh-salt water mixture zone is moving. The problem is worsening because the number of uncontrolled pump-works in the areais increasing. This problem could be alleviated if a Users Community for the whole aquifer were created, itself to watch over the fulfilment of the legal requirements and to regulate the water extractions.

The fresh-salt water interface in a semi-pervious aquifer

The paper determines the location of the steady state interface between fresh and saltwater in a plane coastal aquifer. The lower boundary is totally impervious while the upper one is impervious below land and semi-pervious below the sea allowing an outflow through this part of the upper boundary. The model equations reduce to two boundary value problems, one valid in x 0 here x is measured along the aquifer with the origin at the coast. In each region unknown boundaries have to be determined as part of the solution using boundary and continuity conditions. Two cases are presented using the Dupuit approximation. One where the solution can be written down in terms of elementary functions and the other in which we have to use a phase space analysis.

ESTIMATION METHOD OF TRANSVERSE DISPERSIVITY BASED ON VERTICAL SALT CONCENTRATION DISTRIBUTION IN COASTAL AQUIFER

This paper presents a method for the estimation of transverse dispersivity in a homogeneous isotropic coastal aquifer where salt water intrusion takes place. An approximate solution of the concentration profile on the axis perpendicular to the fresh-salt water interface is derived from a similarity approach and compared with the concentration profile measured in a laboratory experiment. A two-dimensional numerical simulation on salt water intrusion and dispersion is performed using the dispersivities estimated by the proposed method. Numerically predicted concentration profiles agree well with the experimental data. It is concluded that the proposed method is practical for the estimation of transverse dispersivity based on the measured concentration.

Origin, distribution, and evolution of salt-fresh groundwater in North Jiangsu Basin, China

Connate saltwaters are contained within the upper Pleistocene and overlying sediments. The high salinity of phreatic water and subsoil has significant effects on the development of industry and agriculture in the area. This articie is a report on conditions of the salt-fresh ground-water in the North Jiangsu Basin (NJB), China. Connate saltwaters in the western part and within old dunes in the eastern part of the area have been flushed out by infiltrating meteoric water, since regression happened about 1,000 years ago. A broad transition zone of saltwater-freshwater exists due to repeatedly eustatic sea-level fluctuation during the Quaternary period, through analyzing relationships between marine beds and the distribution of salt-fresh groundwater. In the coastal plain, the distribution of salt-fresh water is quite complex. There are four types of vertical distribution represented by chloride and/or Total Dissolved Solids (TDS) profiles: (1) salt-fresh water inversion, (2) salt-brackish water inversion, (3) salt-fresh-brackish water superimposition, and (4) salt-fresh-salt-fresh water superimposition.

Differentiation of Freshwater versus Saltwater Striped Bass by Elemental Scale Analysis

Abstract The differences in concentrations of 10 elements in scales of striped bass Morone saxatilis from several freshwater (<0.1‰), estuarine (0.5–15‰), and saltwater habitats (20–30‰) in the eastern United States were evaluated. Barium, iron, aluminum, calcium, magnesium, manganese, potassium, sodium, strontium, and zinc were measured by flame atomic absorption spectrophotometry. Absorbance values for barium, iron, and aluminum were extremely erratic due to matrix interferences. Discriminant function analysis correctly classified 95% of freshwater and 95% of saltwater fish based on Ca and Mg alone. These two elements were the single best indicator pair. When seven elements were considered, 97 and 95% of fish from fresh water and salt water, respectively, were classified correctly. One-way analysis of variance of individual elemental contents of scales from different salinities consistently distinguished among freshwater, estuarine, and saltwater fish, although not always in a predictable order. Concent...

Sperm motility of sooty grunter, Hephaestus fuliginosus (Macleay), and jungle perch, Kuhlia rupestris (Lacépède), in different salinities

The spawning habitat of jungle perch is unknown. It coexists in the short, fast-flowing freshwater streams of north-eastern Queensland with sooty grunter, a known freshwater spawner. The duration and intensity of sperm motility in various dilutions of sea-water were compared to indicate whether jungle perch spawn in fresh water or salt water. Sooty grunter sperm was most active in salinities of 0 g l-1 and 5 g i-1, and not motile in salinities above 15 g l-1. Jungle perch sperm was not motile in fresh water, but most active in 25 g I-1. These results, together with fish distribution studies in estuaries, indicated that jungle perch probably spawn in the sea in salinities above 25 g I-1..

種々の揚水形態による海岸被圧地下水の挙動 ＩＩ 定常分散モデルによる数値解析

A two-dimensional steady state hydrodynamic dispersion model is used, with the fresh-salt water interface model, to investigate the motion of the coastal confined groundwater in the presence of various pumping patterns. Two expressions of the dispersion coefficient are considered; one is constant over the entire region of the aquifer, and the other is dependent on the flow velocity of the groundwater. The main results are as follows : 1) As the groundwater is pumped more inland, salt water intrudes more inland, whereas the pumping in the lower layer of the aquifer near the coast is effective to prevent the seawater intrusion; 2) in the upper layer pumping, the fresh-salt water interface model serves as a convenient method for approximate analyses and predictions of seawater intrusion into the coastal confined aquifers.

種々の揚水形態による海岸被圧地下水の挙動 Ｉ 淡塩水境界面モデルによる数値解析

種々の揚水形態による海岸被圧地下水の挙動 Ｉ 淡塩水境界面モデルによる数値解析

分散を考慮した海岸地下水の挙動に関する研究 ＩＩ 二次元定常モデルによる数値解析

The unsteady state two-dimensional hydrodynamic dispersion model is used to simulate the seawater intrusion into confined coastal aquifers in response to the tide and to the sudden change in discharge of groundwater in the upstream region.The main results are as follows : 1) Salt water intrudes most inland at the mean sea level in the ebb tide stage, as in the case of the fresh-salt water interface model by KISHI and INOUCHI (1984), and the transition zone from fresh water to salt water becomes widest at that sea level. 2) The movement of isocontours of concentration induced by the sudden change in groundwater discharge retreats faster than it advances and that movement is comparable with the fresh-salt water interface movement computed by the interface model of KAKINUMA et al. (1984). 3) The concentration distribution in response to the tide computed with higher values of the storage coefficient of the confined aquifer is somewhat different from the one obtained by using PINDER and GRAY'S (1977) approximation to the mass conservation equation. This difference, however, is negligible in field situations, with lower values of the storage coefficient.

島しょ部における地下水汚染に関する研究 Ｉ 興居島における地下水への海水侵入

This report deals with the problem of the groundwater pollution caused by seawater intrusion into phreatic and confined aquifers of Gogo Island, Ehime Prefecture. Groundwater levels and chloride ion concentrations in shallow wells were measured in five districts on this island from August 1983 to December 1984. High chloride ion concentrations far greater than 200 ppm, the standard value of city water, were found in coastal regions of the Yura district, whereas the level were very low in other districts. In the Yura district, groundwater levels and chloride ion concentrations in deep wells as well as tide levels were measured. Chloride ion concentration profiles show the rapid increase of the concentration in the neighborhood of the well bottom. A modified KISHI and INOUCHI' s model to analize the variation in the groundwater level and fresh-salt water interface in response to the tide was applicable to a confined aquifer with an exponentially varying thickness. The thickness of the confined aquifer estimated from this analysis was in fairly good agreement with the one obtained by the boring examination.

The regional unsteady interface between fresh water and salt water in a confined coastal aquifer

An areal two-dimensional model to describe the unsteady motion of the fresh-salt water interface and the groundwater level in a confined coastal aquifer is first presented and then applied to the confined groundwater in the estuaries of the Naka and Kiki rivers in Japan. Starting from the basic equations of the groundwater flow, two equations are derived; one equation of the effective water level and one equation of the interface. The first equation describes a very rapid variation of the effective groundwater level and the second equation describes a very slow variation of the interface with time. In order to find solutions of these equations under the boundary conditions in practical field problems, the numerical scheme based on Galerkin finite-element technique was employed. Using this numerical scheme, transient positions of the groundwater level and the interface were calculated in the above-mentioned two regions and compared with the available field data. It was found that the calculated results agree rather well with the data.

4414333 Compositions for depolluting fresh water and salt water bodies

4414333 Compositions for depolluting fresh water and salt water bodies