Evaporation control in a water reservoir

Abstract

The controlling of part of vast quantities of water that have been evaporated is aproper mean of providing adequate water supplies. The monolayer (film)technique is used in order to cut down the rate of evaporation without any seriouseffect to the water quality and to the human health. However, a lot of methodscan be used to retard the evaporation but because of technical and economicalfeasibility, not all of them can be used everywhere.The purpose of the thesis is to investigate the possibility of applying themonolayer film technique on Istanbul water storages and determine the effect ofthese methods on water quality and on environment. Moreover, this study aims todetermine an appropriate model for computing rate of evaporation from Istanbul.Furthermore, this study was conducted at Kaoithane (near pipli) on two tanks, oneof which was treated with a monolayer and another left un-treated for comparison.The use of chemical methods (i, e. mechanical oil) and physical method (i, e.floating cover from ping pong balls), indicated that, floating cover represented agood result even though the chemical method may save the evaporated water bymore than 90 per cent, but these chemicals may create environmental pollutionwhen the film is removed by the wind action. In addition, in the last few years thedrought conditions facing Istanbul has resulted into an increase in evaporatedwater, this makes the application of the monolayer technique to be very importantin providing a reliable water supply. About 62 million cubic meters of water wasevaporated from Istanbul during 1994 .