Abstract:
Rivers are one of our most important natural resources, However rivers also continue to be the carriers of waste water, Those who deal in water management will have to make many critical decisions concerning the treatment necessary before discharge into the streams, or whether the discharge, in fact, can be made. In many cases the decisions will be critical in that the results of the decisions will not be undone easily.
A prime consideration in stream assimilative capacity is dissolved oxygen. A positive dissolved oxygen content must be maintained to prevent putrefecation, In the process of assimilation, oxygen is consumed by organic load carried in the stream, by the benthal demand, and by the respiration of plants and plankton. Oxygen is provided to the stream by diffusion from the atmosphere and by photosynthesis. These elements of oxygen production and oxygen consumption are interrelated.
The use of mathematical models for water quality studies has gained wide acceptance. Many of them models are complex and use sophisticated rate constaints and interrelationships of a wide variety of parameters, which results in extensive calibration and field verification. Complex models are too
detailed for many planning studies. In this paper, a model to simulate dissolved oxygen concerntration and to calculate biochemical oxygen demand, has been presented. The model has the capability to check dissolved oxygen concentration in the stream System against a prespecified target level dissolved oxygen concentration. If the minimum D.O. level is found to be below the target D.O.level, the program has the capacity to compute the required amount of flow augmentation to bring the D.O. level to required level in the system. The computer program has been based on DOSAG-1 model of Texas Deptt, of water Resources, U.S.A. The computer program has been tested with actual data of a river stretch, The model was successfully run on Hindon river (U.P. ) data, The dissolved oxygen profile was compared with actual data and the hand calculated data, the results are quite good. The paper gives all the details of c.he model and output. The paper will be very useful for taking up any river stretch and running DO SAG model, The basic theory, usage of the model etc, are also given.
