Simulation of Spatial Distribution of Fish Species in 200 Km Stretch of Tungabhadra River on the Basis of Oxygen Variability

Abstract

Rivers and streams have always been the major sources of drinking water for various villages and towns of developing and developed countries. India has number of rivers supplying water throughout the year. The concept of setting industries near rivers solves the problem of waste disposal. Since decades, many industries are disposing their waste water in rivers. This trend has reached to such an extent that it is adversely affecting the biological, chemical and physical aspects of the river. Heavy Discharge of effluents and sewage in a river may cause the degradation of water quality. The most important factor required for the life to exist in water is Dissolved Oxygen. An optimum amount of dissolved oxygen i.e., 6 mg/l is required for the healthy growth of ecosystem. In order to study how the effluent and sewage discharge affects the aquatic life and the spatial distribution of fish species, Dissolve Oxygen is simulated throughout the river using QUAL2K. The simulated model is then used to locate the indicator species on the river on the basis of dissolved oxygen level. Various hypothetical cases of effluent flow and the effluent loads are taken. Various hypothetical simulations are prepared showing the spatial distribution of fish species and DO level in the river stretch. These models are then compared among each other. The comparison reveals how the spatial distribution and species diversity of some fish species is varying with the variation in the effluent load and flow in the river. The best model containing maximum diversity of fish species is selected and the corresponding effluent discharge corresponding is considered to be the optimum.