TR-6 : Water quality modelling of rivers

Abstract

Water quality in flowing waters, is closely linked to the total water quality in the basin and hence it becomes imperative that water quality assessment and river basin planning are closely related. For any proper river basin planning, whether long range of short term, before going into alternative plans for development it is very essential to combine it with water quality problems, hydrology and analyses. A water quality model is a set of mathematical statements representing conditions of a stream. Such models can be used to predict water quality under varying circumstances.

The report begins with a general introduction of important role water plays in the life of human being and their surroundings. A brief resume of various water quality parameters has been organised to bring out the crucial physical, chemical and biological parameters. This follows by a detailed account of various water quality models, their suitability and a brief procedure for building the water quality model.

The report presents two mathematical models one for nitrification in streams and the other one describes DO-BOD model. The complete details pertaining to development of models, mathematics involved and data requirement has been spelled out. The report also gives the computer listing of the two models alongwith input and output from the models. The presentation has been made with a view to assist the field engineers to generate the data, run the data on the model and to get the output in the form of usable information.

The report also discusses the data requirements. :Seeping in view the Indian conditions and gives a step by step procedure for evolving single, useful models, for the use of field engineers.

The type of data required for such modelling studies has also been discussed. it has been stressed that it is not necessary to include all conceivable parameters in the model but it would be suffice to include important parameters like dissolved oxygen, pH, turbidity, conductivity, temperature, ORP, solar radiation intensity and chloride. Time sequence of data is also important, has been brought out.

The report ends with definite conclusions and an exhaustive list of references.