The use and waste of water in a third world city

All over the world, cities that are crossed by large rivers, have the great advantage of being able to meet their water needs. In the humid tropics, such cities should normally not experience water scarcity.Ilorin, the city under study is crossed by two fairly large rivers. The town is just about 100 km² in area with a population less than 500,000. 3km E of the city, is a dam with a storage capacity of 43 million m³. The daily water production to the city is 661/person. When it is realized that less than 25% of the houses in the city have modern sanitary conveniences, then 661/person per day borders on over supply. Yet there is the cry of inadequate water supply from sections of the city.The habits of the city dwellers make them waste water. For example, mouth brushing alone takes about 2.4 I/person when the tap runs continuously. Secondly a bath with a 221 bucket of water is adequate for an adult, but when a shower bath is taken, about 841 will be required for about 15 minutes.This paper has examined the use and waste of water among the physical strata in the city. These strata coincide with the socio-economic strata.For an affluent class, a threshold water requirement of 521 is manageable, whereas in the Government Reservation area, the average is 82 1 (often includes waste). For the indigenous area, about 351 per day for an individual is the need, though the demand might be much higher than this value.     

Acid mine drainage contaminates groundwater of a Tennessee watershed

Water samples were collected from 18 natural springs within the West Fork of the Obey River watershed. Overton County, Tennessee, to determine if groundwater was adversely affected by runoff from abandoned surface coal mines Six springs were found to be affected severely and deemed unfit as a source of potable water Water quality of the remaining springs was essentially unaffected it appeared that proximity to surface mines, elevation at the outflow, and geology of the surrounding strata determined the quality of the groundwater The unit is jointly supported by Tennessee Technological University, the Tennessee Wildlife Resource Agency, and the US. Fish and Wildlife Service     

210Pb dating of scottish lake sediments,afforestation and accelerated soil erosion

Changes in the rate of soil erosion in lake catchments can be identified from changes in the rate of sediment accumulation in lakes. Here we compare recently afforested sites with non-afforested sites in the Galloway area of Southwest Scotland. We show that lakes with non-afforested catchments have slow, constant sediment accumulation rates, whereas lakes with recently afforested catchments have changes in accumulation that parallel the known history of afforestation. For Loch Grannoch the sediment accumulation rate increases from 0.1 cm yr^?1 to over 2 cm yr^?2 during the disturbance period. Data from L. Skerrow, however, suggest that the rate might decline to predisturbance levels after approximately 10 years as the forest canopy closes and drainage channels stabilize.     

Distribution of elements and minerals between a coal and its overlying sedimentary rocks in a limnic environment

Previous studies have shown that the Pewee coal, which outcrops in the Wartburg Basin in northeast Tennessee (U.S.A.), formed in an upper delta-plain (limnic) environment and had not been subject to marine conditions. Most elemental concentrations decrease upwards, from the base to the top of the coal; however in some locations, several elements show significant increases in concentration at the very top of the coal. Correlation coefficients for elements within the coal and to a lesser degree, the sediments, reflect typical clay minerals. The major mineral phases identified were kaolinite, illite, chlorite, siderite and quartz.Although minor lateral variations in chemical and maceral composition occur, the Pewee coal is relatively homogeneous within the study area. Elements which tend to be soluble in low-pH solutions (especially Ca) may have reacted with fluids coming from the peat and have been transported away from the coal-sediment contact. Chlorite is absent in the coal, perhaps due to its solubility in an acid environment. With these few exceptions, there is little direct evidence that diagenetic processes influenced the movement of elements from the coal into the sediment, or vice versa.The decrease in elemental concentrations upward in the Pewee coal is thought to result from a gradual decrease in the amount of detritus being brought into the Pewee swamp. The increase in abundance of detritus at the top of the coal in some locations suggests a sudden change in environmental conditions, perhaps as the result of the establishment of a new distributary system.     

PRAGMATISM vs RIGOUR: A Debate on the Resolution Of Disparate Analytical Data on Four Canadian Iron - Formation Reference Samples

The analytical data received in an inter-laboratory study of four Canadian reference samples were treated by two different methods in order to arrive at "usable values" for the concentration of each constituent. The first method ("Select Laboratories"), proposed by S. Abbey (S.A.), is based on the fact that some laboratories consistently produce better results than others. S.A. suggests an approach which permits isolation of results from such laboratories, calculation of a mean or a median of such results and use of one or the other as the concentration of a constituent. That approach involves a degree of subjectivity and S.A. attempts to demonstrate the validity of his approach by means of several tests applied to the results obtained for the four samples.     

Volcanic and tectonic evolution of the Northern Antarctic Peninsula—Late Cenozoic to recent

Field investigation together with a number of geochemical petrographical analyses, as well as absolute K-Ar age determinations and geophysical data, allow the recognition of an evolutionary sequence of geodynamic events which have affected the northern region of Antarctic Peninsula and the adjacent islands.A significant volcanic calc-alkaline belt, which developed on the northwestern margin of the Antarctic Peninsula during the Cretaceous to Middle Tertiary, is indicative of active subduction of the Antarctic plate in that area. This activity decreases during the Lower Miocene, giving way to an expansive phase represented by the Bransfield Rift. These extensional processes are dominant during the Pliocene, creating a rift system in southeastern Bransfield towards Larsen. Both the Bransfield and Larsen systems comprise one “fan-like rift system”, associated with the Prince Gustav Rift and the Scotia Arc micro-plate. Ejection of abundant pyroclastic material generated a large plateau of palagonite hyaloclastites of basaltic alkaline composition. During the Pleistocene-Recent, the extensional activity continued, as evidenced by the active volcanic fractures represented in Bransfield by the Deception, Penguin and Bridgeman volcanic centres; in the Prince Gustav Rift by Paulet Islands and others, and in Larsen by the Coley, Seal Nunatak and Argo volcanic centres. The latter is characterized by basaltic olivine-alkaline effusions. These rifts and the continental blocks are affected by a series of fractures with a N60°–70°W strike, which could be directly associated with the Hero Fracture Zone extending northwest of the South Shetland Islands Trench.     

The structural state of iron in oxidized vs. reduced glasses at 1 atm: A57Fe Mössbauer study

A general model for the structural state of iron in a variety of silicate and aluminosilicate glass compositions in the systems Na₂O-Al₂O₃-SiO₂-Fe-O, CaO-Al₂O₃-SiO₂-Fe-O, and MgO-Al₂O₃-SiO₂-Fe-O is proposed. Quenched melts with variable Al/Si and NBO/T (average number of nonbridging oxygens per tetrahedrally coordinated cation), synthesized over a range of temperatures and values of oxygen fugacity, are analyzed with⁵⁷Fe Mössbauer spectroscopy. For oxidized glasses with Fe³⁺/∑Fe>0.50, the isomer shift for Fe³⁺ is in the range ～0.22–0.33 mm/s and ～0.36 mm/s at 298 K and 77 K, respectively. These values are indicative of tetrahedrally coordinated Fe^3?. This assignment is in agreement with the interpretation of Raman, luminescence, and X-ray,K-edge absorption spectra. The values of the quadrupole splitting are ～0.90 mm/s (298 K and 77 K) in the Na-aluminosilicate glasses and compare with the values of 1.3 mm/s and 1.5 mm/s for the analogous Ca- and Mg-aluminosilicate compositions. The variations in quadrupole splittings for Fe³⁺ are due to differences in the degree of distortion of the tetrahedrally coordinated site in each of the systems. The values of the isomer shifts for Fe²⁺ ions in glasses irrespective of Fe³⁺/∑Fe are in the range 0.90–1.06 mm/s at 298 K and 1.0–1.15 mm/s at 77 K. The corresponding range of values of the quadrupole splitting is 1.75–2.10 mm/s at 298 K and 2.00–2.35 mm/s at 77 K. The temperature dependence of the hyperfine parameters for Fe²⁺ is indicative of noninteracting ions, but the values of the isomer shift are intermediate between those values normally attributable to tetrahedrally and octahedrally coordinated Fe²⁺. The assignment of the isomer-shift values of Fe²⁺ to octahedral coordination is in agreement with the results of other spectral studies. For reduced glasses (Fe³⁺/∑Fe≈<0.50), the value of the isomer shift for Fe³⁺ at both 298 K and 77 K increases and is linearly correlated with decreasing Fe³⁺/∑Fe in the range of \(f_{O_2 } \) between 10^?3 and 10^?6 atm when a single quadrupole-split doublet is assumed to represent the absorption due to ferric iron. The increase in value of the isomer shift with decreasing \(f_{O_2 } \) is consistent with an increase in the proportion of Fe³⁺ ions that are octahedrally coordinated. The concentration of octahedral Fe³⁺ is dependent on the \(T - f_{O_2 } \) conditions, and in the range of log \(f_{O_2 } \) between 10^?2.0 and 10^?5 a significant proportion of the iron may occur as iron-rich structural units with stoichiometry similar to that of inverse spinels such as Fe₃O₄, in addition to isolated Fe²⁺ and Fe³⁺ ions.     

Effect of treatment with reserpine on the change in filtration rate of Mytilus edulis subjected to dissolved copper

Exposure of specimens of Mytilus edulis to dissolved copper leads to a fall in the filtration rate measured in whole animals. The copper concentration leading to a 50% reduction in the filtration rate was found to be 0.094 mg I⁻¹. This effect was abolished on depletion of the monoamine content of the animal using reserpine. It is suggested that there may be a chemosensory mechanism present in the animals which responds to increased levels of metals in the seawater leading to a reduction in the rate of ciliary beating and mediated via the branchial nerve.     

A reduced-rank prediction model of stream-channel size response to traditional agricultural land-use practices in southwestern Nigeria

Stream-channel morphologic responses are found to be related to different parameters measuring traditional agricultural land-use patterns and practices in 50 small headwater basins in southwest Nigeria. The problem of intercorrelations among these parameters made it initially difficult to establish their precise channel enlargement effects and to calibrate an impact prediction model. Through factor analysis of the 22 land-use and morphometric parameters, six factors identified as measures of traditional land-use practice, farm size, planting activities, shortened fallow, relief and overland flow, were found to account for 86% of the variance in the data. The factor-defining variables are length of cropping period, areas in short fallow, farm-plot size, length of farm preparation, relief ratio and overland flow. In a multiple regression analysis, only the first three variables were found to be statistically significant in explaining stream-channel morphologic responses. Thus, areas in short fallows, average farm size and length of cropping period adequately described those aspects of the traditional farming practices that affect basin hydrologic and channel responses. Since these variables were orthogonally derived, they formed the basis for the evaluation of the channel impact status of traditional land-use activities. The duplication of information and effects in the original 22-variable full-rank model were removed while utilizing the three-factor reduced model.