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[en] This working paper discusses the concepts and background information for using isotope date in geohydrology. This kind of review is necessary for evaluation of the present status of such work, to indicate gaps in our knowledge and to plan future work. This report does not include detailed mathematical formulations, as these are available in the references quoted; these should be consulted in detail before the actual discussion of the panel. A discussion of interpretation of isotope data in hydrology is closely related to the general problem of models and interpretation methods in hydrology. Therefore this discussion will start with a brief survey of current interpretation of models in hydrology.
[en] Stable isotope measurements of the lake waters made in various parts of the world have shown that lakes are considerably enriched with respect to stable isotopes compared to the precipitation, runoff and groundwaters in the same region.
[en] Glaciers, being an integral part of the Earth’s natural system, serve as the most reliable and sensitive indicators of climate change. Besides, they constitute a significant component of the hydrological regime. It is estimated that over 10,000 glaciers are receding at a rate of 100 to 200 feet (30 to 60 metres) per decade in the Indian Himalayas. In fact the melting is twice as fast since the year 2000 as they were 25 years before, due to human induced climate change. And it is projected that two-thirds of Himalayan glaciers will vanish by the end of this century if the current rate of greenhouse gas emissions continue. Tracers like Deuterium, Tritium, Oxygen-18 of water molecule and other dissolved isotopes have potential applications in climate studies including glacier dynamics, for isotopes being part and parcel of water molecules can trace the movement of large water masses more accurately. For the first time, d17O isotope has been used in the Indian context to infer the influence of local moisture recycling at the continental site. These studies of DAE-BRNS provide new evidence that improves the current understanding of the forcing factor behind glacier advances and retreat in the Western Himalayas
[en] The successful application of environmental isotope techniques in hydrology requires close cooperation between the isotope worker and the hydrologist. It is important to understand the problems that hydrologists are interested in solving. Ordinarily the basic problem for the hydrologist, as it is in all scientific fields, is the prediction: How will a hydrologic system respond to a given set of conditions? or what will happen if new conditions are introduced in the system. The purpose of the isotope worker,therefore, is to find ways of helping the hydrologist understand a system and predict its response. In groundwater studies, hydrologists are interested in defining the boundaries and the aquifer characteristics such as the permeability distribution in the groundwater system. Telling the hydrologist the age of the water at a given point of the system may not be of much value to him. It is much more useful to identify the recharge and the discharge regions the interconnections between different surface and groundwater bodies and to give a reasonably accurate estimate of regional permeability of the aquifer.
[en] We would like to confirm our commitment to support our Member States in improving nutrition in these difficult times. Have a look at the suggestions for conducting IAEA nutrition studies during the COVID-19 pandemic. Mainly working from home, we continued with our activities in the second half of 2020 and conducted meetings and training workshops in a virtual format. We have discussed progress of research projects, identified new research agendas, strengthened expertise in deuterium-based isotope techniques and established new collaborations with nutrition societies. We contributed to the Micronutrient Forum 5th Global Conference CONNECTED 2020 and to the 11th Africa Day for Food and Nutrition Security. Check out new publications presenting results from different IAEA-supported projects.
[en] The virus responsible for COVID-19, originating in animals, emerged in humans in late 2019 and upended the world as we know it. While it is the first disease in over a century to cause daily lives and economies worldwide to grind to a halt, it is not the first disease to cross from animals to people. More than 60 per cent of diseases now affecting humans started in animals — and with improved surveillance and animal disease control, they could be stopped in their tracks. This is what underlines the importance of global initiatives like the Veterinary Diagnostic Laboratory (VETLAB) Network, through which veterinary labs exchange information, share best practices and support each other. The VETLAB Network is maintained by the IAEA, in partnership with the Food and Agriculture Organization of the United Nations (FAO), and is funded through the Peaceful Uses Initiative and the African Renaissance and International Cooperation Fund.
[en] The following papers, oral contributions and discussions, were assembled informally by the Scientific Secretariat of the Panel Meeting on Interpretation of Environmental Isotope Data in Hydrology (Vienna, Austria, 24-28 June 1968). They have not been edited formally, so that minor changes have not been cleared with the original authors. They are reproduced for informal distribution as they may be helpful to hydrologists and others interested in the application of environmental isotopes in hydrologic studies.
[en] Specific techniques that have proven successful in evaluating P effects are described and discussed in relation to their application to( field research investigations. 'A'-values using seed placement of the tagged-P carrier, while primarily a technique used to measure available soil-P or the relative availability of different P carriers, has proven a reliable means of estimating the effects of many secondary factors on soil-P availability, i.e. soil moisture stress, biological fixation or release of soil-P, volume of root exploitation, or soil temperature, etc. The relative significance of criteria such as 'A'-value obtained from field experiments growth chamber 'A'-values, Scott A. Russell's Pe-values, McConachy's IDF-values, phosphorus fractionnation (Al, Fe, Ca bound-P), and NaHCO3 extractable-P is discussed in relation to data obtained on four sub-group profiles of a chernozemic soil developed on medium textured lacustrine materials. The P-32 injection technique has proven a simple and rapid means of measuring the effects of fertility treatments, soil type and moisture stress on the rooting habits of wheat. A modified plot design for field experiment was discussed. (author)
[en] Methods of reducing experimental error. were discussed. Some general measures to ensure good management of a field experiment were suggested. Factors affecting test crop response to fertilizer application in a field experiment such as the prevailing weather conditions, the previous crops grown at the selected experimental site and the way the soil was managed were discussed. The importance of standardizing data recording and its adaptation for computer processing was stressed. The estimation of isotope requirements for a field fertilization experiment was diseased in detail. (author)