MATHEMATICAL MODELLING OF URBAN WATER SUPPLY SYSTEM CRISIS

Resumo

Purpose – The chaotic growth of cities results in numerous problems related to public health and urban environment. One of these problems is the crisis in urban water supply systems. The objective of this paper is to develop a mathematical model for the water supply system crisis in urban environment (WSC) able to tackle with the ambiguity of the real available data.

Design/methodology/approach – The applied methodology comprises the following steps: (1) identification of the influencing factors in WSC; (2) proposal of a conceptual model for WSC description; (3) gathering and simulation of the necessary and available data; (4) optimization of the conceptual model parameters; and (5) verification of the proposed model performance.

Findings – The results indicated that there is a great amount of influencing factors in WSC (showed in the complete text); the conceptual model that was developed is composed by two others partial models ( ). The first partial model explained the water consumption ( ),and the second partial model explained the water availability ( ), in which functions are related to influencing factors in water consumption (i.e. temperature, relative humidity, rainfall, revenues collected, unemployment indicator), and functions are related to the influencing factors in water availability (i.e. total water-loss, intermittence in water supply system). The proposed conceptual model has showed good agreement to the simulated data.

Originality/value – The paper is among the first works to describe a WSC model and to analyze the possibility of applying fuzzy logic to deal with the ambiguity of the real data. The water supply crisis in urban environments was adequately modelled.