USE OF RADIOISOTOPES IN WATER RESOURCES ENGINEERING

Abstract

The present dissertation mainly aims at bringing together and discussing the available information on the use of radioiso-topes for solution of problems connected with measurement of dis-charge of streams, seepage from canals, detection of path of seep-age in dams, sediment transport studies, surface and depth measure-ment of moisture and density of soils. Various experiments conduct-ed in India by the Bhabha Atomic Research Centre, Bombay, to solve various problems with the use of radioisotopes are illustrated to give an idea of the development of nuclear techniques in the Water Resources Engineering in India, The first thapter deals with the background concepts of radioisotopes, and their radiation, characteristics of important radioisotopes generally used in practice. Examples of various uses as radiotracers and sources of radiation in different fields of medicine, industries, agriculture and hydrology - are given. The selection, physical and chemical properties of radioisotopes for water studies, radiation detection and equipments used, cost of various radioisotopes and Nuclear Electronic Instruments are dealt in this chapter. The advantages of radiotracers for stream flow measurements overother conventional methods, the different techniques, theories, injection and measurement procedures, mixing length etc. are dis-cussed in Chapter 2. Experiments conducted in India for stream-flow measurements of Tapi River, Tons River and Mutha River by radio-isotope methods are explained. The Chapter 3 deals with the various theoretical and experi- (vii) -mental methods including raioisotope techniques for the evaluation. of seepage from unlined canals. The studies made on Ganga Canal for the evaluation of amount of seepage and the results obtained are illustrated. The study of flow path of seepage in the coffer dam of Srisailam project, .Aliyar dam and Bhadra dam are explained. The selection and preparation of radiotracers, injection and equipments used for studying the movement of sand and silt are dealt in Chapter 4, Various experiments conducted in solving the complex problems of movement of sand and silt in harbours and rivers in India are explained in this chapter, The different sedi-ment concentration gauges developed and their performance and possible improvements are discussed. The Chapter 5 deals with the various methods for the deter-mination of moisture and density of soils including nuclear methods and their advantages. The types of nucleonic gauges for surface and depth measurements of soil density and moisture are explained and the results of experiments conducted by the author at the Isotope Laboratory, U.P. irrigation Research Institute. Roorkee, are given. The 'wide application of these gauges for various investigations, construction and quality control are discussed. in the last chapter, the author's conclusions are given for the scope and development of nuclear techniques to take beat ad-vantage of the use of radioisotopes in solving many intricate problems which cannot be solved easily by the usual conventional methods.