Water and Food in Developing Countries in the Next Century

1998 ◽  
Author(s):  
M. Yudelman
Keyword(s):  
Global Warming ◽  
Fresh Water ◽  
Sea Water ◽  
Hydrological Cycle ◽  
Saline Water ◽  
Weight Of Evidence ◽  
Agricultural System ◽  
Polar Regions ◽  
The Difference ◽  
The Persian Gulf

The world’s supply of water is fixed. It is estimated that 97% of the world’s water exists in the oceans, 2.2% exists as ice and snow, mostly in the polar regions, and only about 0.7% of the total supply is the freshwater that sustains mankind, including the global agricultural system. This quantity of freshwater — around 40,500 km3 — which is the difference between precipitation and evapotranspiration, is continuously replenished by nature’s hydrological cycle. Most climatologists and hydrologists agree that there is no natural process short of climate change, especially global warming, that can increase the world’s rainfall and so the supply of freshwater. The greater the warming, the larger the expected increase in precipitation. One “simple level of analysis” suggests that global warming of 30° C could well lead to a 10% increase in evaporation and an average increase in precipitation of 10%. The biggest increases would be at high latitudes, smaller increases would occur close to the equator (Gleick, 1992). The weight of evidence suggests that this is unlikely to happen within the next several decades (Rosenzweig, 1994). It is an open question, though, as to what might happen in the second half of the next century. There are some manmade processes that can increase the supply of fresh water. One of the most important of these is the conversion of saline water from the ocean into fresh water by removing salt through desalinization or by filtration. Thus far, however, the processes that have been developed are highly energy intensive and costly; the plants presently in operation are mostly in the oil-rich, water-poor nations of the Persian Gulf. It is estimated that there are more than 11,000 desalting plants operating worldwide, but together they produce less than 0.2% of the world’s total fresh water (Postel, 1991). The costs of desalting sea water range currently from about $0.80 to $1.60 m-3, and costs of treating brackish water are about $0.30 m -3, well above the costs of fresh water used for irrigation (Wolf, 1996).

scholarly journals Investigation into Groundwater Resources in Southern Part of the Red River’s Delta Plain, Vietnam by the Use of Isotopic Techniques

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2120 ◽  
Author(s):  
Van Lam ◽  
Van Hoan ◽  
Duc Nhan
Keyword(s):  
Water Resources ◽  
Fresh Water ◽  
Sea Water ◽  
Saline Water ◽  
Groundwater Resources ◽  
High Rate ◽  
14C Dating ◽  
Study Region ◽  
Delta Plain ◽  
Pleistocene Aquifer

Groundwater in the Red River’s delta plain, North Vietnam, was found in Holocene, Pleistocene, Neogene and Triassic aquifers in fresh, brackish and saline types with a total dissolved solids (TDS) content ranging from less than 1 g L−1 to higher than 3 g L−1. Saline water exists inHolocene aquifer, but fresh and brackish water exist in Pleistocene, Neogene and Triassic aquifers. This study aims at the investigation into genesis and processes controlling quality of water resources in the region. For this isotopic, combined with geochemical techniques were applied. The techniques include: (i) measurement of water’s isotopic compositions (δ2H, δ18O) in water; (ii) determination of water’s age by the 3H- and 14C-dating method, and (iii) chemical analyses for main cations and anions in water. Results obtained revealed that saline water in Holocene aquifer was affected by seawater intrusion, fresh water in deeper aquifers originated from meteoric water but with old ages, up to 10,000–14,000 yr. The recharge area of fresh water is from the northwest highland at an altitude of 140–160m above sea level. The recharge water flows northwesterly towards southeasterly to the seacoast at a rate of 2.5m y−1. Chemistry of water resources in the study region is controlled by ferric, sulfate and nitrate reduction with organic matters as well as dissolution of inorganic carbonate minerals present in the sediment deposits. Results of isotopic signatures in water from Neogene, Triassic and Pleistocene aquifers suggested the three aquifers are connected to each other due to the existence of faults and fissures in Mesozoic basement across the delta region in combination with high rate of groundwater mining. Moreover, the high rate of freshwater abstraction from Pleistocene aquifer currently causes sea water to flow backwards to production well field located in the center of the region.

scholarly journals The isotopic record of oxygen in phosphates of fossil fish - Devonian to Recent

1992 ◽  
Vol 6 ◽  
pp. 171-171
Author(s):  
Yehoshua Kolodny ◽  
Boaz Luz
Keyword(s):  
Isotopic Composition ◽  
Fresh Water ◽  
Sea Water ◽  
Thermal Structure ◽  
Small Variation ◽  
Isotopic Analysis ◽  
Fresh Water Fish ◽  
Altitude Effect ◽  
The Difference ◽  
Fluor Apatite

The isotopic composition of oxygen in the phosphate (δ18Op)was determined in 159 fish bones and teeth from museum collections throughout the world. The fossils were both marine and fresh-water ranging in age from the Devonian to the Recent. In 45 of those we also determined the isotopic composition of oxygen and carbon of the lattice carbonate in apatite (δ18Oc and δ13C). In most cases the isotopic results are compatible with previously available geological information: the difference between marine and fresh water, the indication of previously known warm and cold time periods, and the ranking of fishes from warm to cold according to their inferred life habitat.Three fish specimen from the Devonian of the Orcadian Basin in Scotland yield results which are compatible with the thermal structure of a stratified lake. The isotopic analysis of Inocentrus vulgaris, a fish found inside Cretaceous inoceramids, yields normal marine δ18Op. Hence we favor the suggestion of Tourtelot and Rye (1969) that 18O depleted inoceramids did not deposit their shells in isotopic equilibrium with sea water.The relationship between δ18Op and δ18Oc suggests early diagenetic replacement of an originally phosphatic phase by carbonate fluor apatite (CFA). This conclusion is in accord with REE studies of fish fossils. The correlated latitudinal variation in δ18O of meteoric water and temperature should result in a small variation of δ18Op in fresh water fish. The large range in δ18Op of Recent fish is the outcome the “altitude effect” (Dansgaard, 1964) i.e. of the existence of Recent high altitudes, and sharp morphological gradients.

Prototype for Solar Powered Chip-Ice Production Facility

2017 ◽  
Author(s):  
O. A. Huzayyin ◽  
M. S. El Morsi ◽  
M. A. Serag-Eldin ◽  
M. F. El-Bedaiwy
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Saline Water ◽  
Sole Source ◽  
Ambient Temperatures ◽  
Heat Leakage ◽  
Solar Powered ◽  
Ice Production ◽  
Prototype Design ◽  
Crushed Ice

Fishermen in highly isolated communities like Shallatin and Halayeb (Southern Egypt) suffer from the fouling of their catch before reaching the markets, due to the prevailing high ambient temperatures. Thus, they resort to block or crushed ice to cool their catch. Since fresh water is unavailable naturally, energy is needed to produce the fresh water from sea water, as well as to operate the chiller for ice production. Hence, employing solar energy as the sole source of energy for manufacturing ice, and producing the ice straight from saline water provides independence from both the electric grid and fresh water resources. A prototype solar powered facility for chip ice production from saline water has been designed, manufactured and erected in Shallatin for this purpose. The prototype, basically an ice production machine provides facilities for fish chilling and refrigeration compartments for vaccines, medicines and food products. The produced ice can be easily transported in to fishing boats in 10 kg plastic boxes that are easy to carry and handle. The prototype design employs many standard parts to cut costs and development time. Adequate ventilation with natural heat leakage to the cool surfaces of equipment (e.g. external surfaces of tanks and their piping) produces the desired room temperature without need for a fan coil unit, as discovered in actual implementation. The design should be applicable to all environments similar to Halayeb and Shellatin, which includes many places on the Red sea in the Gulf area and Africa. It is thus expected to be attractive for commercial exploitation in those places, and offers opportunities for local manufacturing and exportation of industrial products.

Oxygen Consumption of the Euryhaline Fish Aholehole (Kuhlia sandvicensis) with Reference to Salinity, Swimming, and Food Consumption

1972 ◽  
Vol 29 (1) ◽  
pp. 67-77 ◽  
Author(s):  
B. S. Muir ◽  
A. J. Niimi
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Fresh Water ◽  
Food Consumption ◽  
Sea Water ◽  
Swimming Activity ◽  
Daily Ration ◽  
Significant Difference ◽  
Fish Weight ◽  
The Difference

Active and standard metabolism of Kuhlia sandvicensis increase with fish weight to a power of about 0.8 and active is nine times standard. No significant difference was found between experiments in fresh water and 30‰ sea water at 23 C. At low swimming speeds the fish may be unable to physically take up as much oxygen as at higher speeds. Swimming activity may be essential to circulatory adequacy.Elevated oxygen consumption lasted for 42 hr following a ration of 2.3% of body weight and for 60 hr after one of 4.5%. It amounted to about 76 mg O2/g ration, equivalent to about 16% of the energy of the ration, in both cases. For a nonswimming fish the highest oxygen consumption observed following the maximum daily ration is no more than half of the difference between active and standard rates.

Pengembangan Alat Pemurni Air Laut sebagai Media Pembelajaran Fisika SMA pada Materi Pemanasan Global

2021 ◽  
Vol 4 (2) ◽  
pp. 222
Author(s):  
Ernidawati Ernidawati ◽  
Muhammad Sahal ◽  
Nayla Fauza ◽  
Dina Syaflita ◽  
Defni Satria
Keyword(s):  
Global Warming ◽  
Fresh Water ◽  
Quantitative Data ◽  
Sea Water ◽  
Empirical Test ◽  
Salt Content ◽  
Measuring Instruments ◽  
Design Development ◽  
Analysis Design ◽  
Addie Model

ABSTRACTThe purpose of this study was to develop a sea water purifier and test the validity of a sea water purifier so that it can be used as a medium for high school physics learning on global warming material. The development model carried out is the ADDIE model. The ADDIE model consists of Analysis, Design, Development, Implementation and Evaluation. The data obtained in the form of qualitative and quantitative data. Qualitative data is used to obtain the value of preliminary analysis and validation of tools used in learning. Quantitative data is used to obtain empirical test values by comparing the results of measuring tools made with standard measuring instruments. Based on the results of the empirical test, it was found that the fresh water produced by the developed seawater purifier has good quality because it meets water standards that are suitable for consumption. Based on the research conducted, it was found that the average fresh water produced was 50.33 mL from 1 liter of seawater which was dried for 6 hours per day, and the decrease in salt content of seawater after using this seawater purifier that utilized solar power was 100%. . Based on the results of expert validation which refers to the functionality of the tool, learning elements, ease of use, aesthetics and construction of the tool, the average value of the validity index is 3.78 with a very high category. So it can be concluded that the developed seawater purifier is valid and can be used as a medium for learning Physics on global warming material.Keywords: sea water purifier, learning media, global warming.ABSTRAK Tujuan penelitian ini adalah untuk mengembangkan alat pemurni air laut dan menguji validitas alat pemurni air laut agar dapat digunakan sebagai media pembelajaran Fisika SMA pada materi pemanasan global. Model pengembangan yang dilakukan adalah model ADDIE. Model ADDIE terdiri dari Analysis, Design, Development, Implementation dan Evaluation. Data yang diperoleh berupa data kualitatif dan kuantitatif. Data kualitatif digunakan untuk mendapatkan nilai analisis pendahuluan dan validasi alat yang digunakan dalam pembelajaran. Data kuantitatif digunakan untuk memperoleh nilai uji empiris dengan membandingkan hasil ukur alat yang dibuat dengan alat ukur yang sudah standard. Berdasarkan hasil uji empiris diperoleh bahwa bahwa air tawar yang dihasilkan oleh alat pemurni air laut yang dikembangkan memiliki kualitas yang baik karena memenuhi standar air yang layak dikonsumsi. Berdasarkan  penelitian yang dilakukan, diperoleh rata-rata air tawar yang dihasilkan 50,33 mL dari 1 liter air laut yang dijemur selama 6 jam per harinya, dan   penurunan kadar garam air laut  setelah menggunakan alat pemurni air laut yang memanfaatkan tenaga surya ini sebesar 100%. Berdasarkan hasil validasi pakar  yang mengacu pada keberfungsian alat, unsur pembelajaran, kemudahan penggunaan, estetika dan konstruksi alat diperoleh nilai rata-rata indeks validitas  3,78 dengan kategori sangat tinggi, sehingga dapat disimpulkan bahwa alat pemurni air laut yang dikembangkan bernilai valid dan dapat digunakan sebagai media pembelajaran Fisika pada materi pemanasan global.Kata kunci: alat pemurni air laut, media pembelajaran, pemanasan global.

scholarly journals Conjecture and hypothesis: The importance of reality checks

2017 ◽  
Vol 13 ◽  
pp. 620-624 ◽  
Author(s):  
David Deamer
Keyword(s):  
Origin Of Life ◽  
Fresh Water ◽  
Hydrothermal Vents ◽  
Origins Of Life ◽  
Weight Of Evidence ◽  
The Earth ◽  
Alternative Hypotheses ◽  
The Origin Of Life ◽  
The Difference ◽  
Hydrothermal Fields

In origins of life research, it is important to understand the difference between conjecture and hypothesis. This commentary explores the difference and recommends alternative hypotheses as a way to advance our understanding of how life can begin on the Earth and other habitable planets. As an example of how this approach can be used, two conditions have been proposed for sites conducive to the origin of life: hydrothermal vents in salty seawater, and fresh water hydrothermal fields associated with volcanic landmasses. These are considered as alternative hypotheses and the accumulating weight of evidence for each site is described and analyzed.

scholarly journals Salinity changes and anoxia resulting from enhanced runoff during the late Permian global warming and mass extinction event

2017 ◽  
Author(s):  
Elsbeth E. van Soelen ◽  
Richard J. Twitchett ◽  
Wolfram M. Kürschner
Keyword(s):  
Global Warming ◽  
Soil Erosion ◽  
Environmental Changes ◽  
Sea Water ◽  
Hydrological Cycle ◽  
Terrestrial Ecosystem ◽  
Late Permian ◽  
Terrestrial Environment ◽  
Shallow Marine ◽  
Extinction Event

Abstract. The Late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focusses on one of the stratigraphically most expanded Permian-Triassic records known, from Jameson land, east Greenland. High resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The extinction event, here defined by a peak in spore/pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 to 8 kyrs, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced runoff, increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more near-shore conditions during and after the crisis. In a period of sea-level rise, such a reduction in salinity can only be explained by increased runoff. High amounts of both terrestrial and marine organic fragments in the first anoxic layers suggest that high runoff, increased nutrient availability, possibly in combination with soil erosion, are responsible for the development of anoxia in the basin. Enhanced runoff could result from changes in the hydrological cycle during the late Permian extinction event, which is a likely consequence of global warming. In addition, vegetation destruction and soil erosion may also have resulted in enhanced runoff. Salinity stratification could potentially explain the development of anoxia in other shallow marine sites. The input of fresh water and related changes in coastal salinity could also have implications for the interpretation of oxygen isotope records and sea water temperature reconstructions in some sites.

scholarly journals Salt tolerance's toll: prolonged exposure to saline water inflicts damage to the blood cells of dice snakes (<i>Natrix tessellata</i>)

Web Ecology ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Vanya Koleva ◽  
Yurii Kornilev ◽  
Ivan Telenchev ◽  
Simeon Lukanov ◽  
Berna Hristova ◽  
...  
Keyword(s):  
Fresh Water ◽  
Black Sea ◽  
Blood Cells ◽  
Prolonged Exposure ◽  
Sea Water ◽  
Physiological Stress ◽  
Saline Water ◽  
World Ocean ◽  
Plasma Sodium ◽  
Mitochondrial Activity

Abstract. Dice snakes (Natrix tessellata, Laurenti, 1768) inhabit oligohaline and brackish waters along the Bulgarian Black Sea coast, where they often forage at sea. Under these conditions, this species should tolerate highly variable blood plasma sodium concentrations for extended time periods, but the effect of high sodium concentrations to blood cell morphology and physiology is largely unknown. In this experiment, we placed adult dice snakes in waters with different salinity for 84 h, representing the three typical saline concentrations in which dice snakes live and forage: 0.2 ‰ NaCl, fresh water, 16 ‰ NaCl, Black Sea water and 36 ‰ NaCl, World Ocean water. We collected blood through cardiocentesis after exposure to each treatment and used Giemsa's solution for staining the formed elements. We registered numerous nuclear abnormalities (nuclear buds, lobes and blebs) in the blood cells of all investigated specimens. In the snakes placed in the waters with high saline concentration (16 and 36 ‰ NaCl) we found numerous cells with ruptured membranes. These snakes also showed increased mitochondrial activity compared to those in fresh water (1.85 and 2.53 times higher, respectively). Our data suggest that even though dice snakes show a remarkable tolerance to waters with increased salinity, prolonged exposure to it induces significant physiological stress in N. tessellata, which poses a clear limit for their ability to stay in the sea for a long time.

scholarly journals The Chemical Changes which occur in Samples of Excretally Polluted Water under Certain Specified Conditions

1923 ◽  
Vol 21 (3) ◽  
pp. 220-225 ◽  
Author(s):  
Robert C. Frederick
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Polluted Water ◽  
Dissolved Solids ◽  
Chemical Changes ◽  
The Difference

The chemical changes which occur in the dissolved solids of sewage on discharge into sea-water have been investigated by several workers (see references 1–11). Some observation on the difference of these changes to those occurring in polluted fresh water have been made by Letts and Richards (6,11). In regard to waters whose saline composition is not such as to preclude their admissibility for potable purposes on this account, Liversidge(12) has made a brief communication on the variation in the free and albuminoid ammonia.

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