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Determination of status of water quality of a river or any other water sources is highly indeterminate. It is necessary to have a competent model to predict the status of water quality and to advice for type of water treatment for meeting different demands. One such model (UNIQ2007) is developed as an application software in water quality engineering. The unit operates in a fuzzy logic mode including a fuzzification engine receiving a plurality of input variables on its input and being adapted to compute membership function parameters. A processor engine connected downstream of the fuzzification unit will produce fuzzy set, based on fuzzy variable viz. DO, BOD, COD, AN, SS and pH. It has a defuzzification unit operative to translate the inference results into a discrete crisp value of WQI. The UNIQ2007 contains a first memory device connected to the fuzzification unit and containing the set of membership functions, a secondary memory device connected to the defuzzification unit and containing the set of crisp value which appear in the THEN part of the fuzzy rules and an additional memory device connected to the defuzzification unit. More advantageously, UINQ2007 is constructed with control elements having dynamic fuzzy logic properties wherein target non-linearity can be input to result in a perfect evaluation of water quality. The development of the fuzzy model with one river system is explained in this paper. Further the model has been evaluated with the data from few rivers in Malaysia, India and Thailand. This water quality assessor probe can provide better quality index or identify the status of river with 90% perfection. Presently, WQI in most of the countries is referring to physic-chemical parameters only due to great efforts needed to quantify the biological parameters. This study ensures a better method to include pathogens into WQI due to superior capabilities of fuzzy logic in dealing with non-linear, complex and uncertain systems.

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Several techniques for the prediction of ammonia volatilization rates from rice paddies are evaluated using experimental data obtained in a wind‐water tunnel, set up to simulate rice paddy conditions. The wind tunnel results suggest that nonuniform surface conditions of waters with short fetch do not significantly limit the use of aerodynamic techniques for the prediction of ammonia volatilization rates. Comparison of volatilization rates predicted with a one‐dimensional aerodynamic technique as well as a two‐dimensional modification of this technique against those predicted from the longitudinal ammonia flux at the downwind section of a wind‐water tunnel yield differences on the order of 10%. Ammonia volatilization rates and aqueous chemistry measured under small enclosures are compared with those measured in the wind‐water tunnel. The results indicate that quantitative assessment of ammonia volatilization losses in the field is possible if air exchange rates in the enclosure are selected which yield a gas phase resistance representative of average wind conditions.