ABSTRACT
The adoption of strategies for monitoring water consumption is essential for water resources management, contributing to the promotion of the sustainability in the water sector. Statistical process control (SPC) charts, which are widely used in the industrial sector, are statistical methods developed to improve the quality of products and processes. The application of this method has reached other areas over the last decades and has recently been identified as an option for environmental monitoring. In this context, the application of SPC charts emerges as an option for water consumption monitoring, whether in a building or an urban scale. Thus, this article aims to analyze the application of statistical process control charts in the monitoring of water consumption of two housing compounds in Joinville, southern Brazil. The methodological procedures include the use of the Shewhart and the EWMA control charts in addition to the non-parametric alternative, the EWMA-SN, assessing the effectiveness of these techniques in detecting water leaks in residential apartment buildings. The data sets, obtained through a telemetry metering system from the water utility, represent a period of 243 days. The results show that control charts are a powerful tool in identifying changes in water consumption patterns, with the EWMA chart flagging the leaks sooner.
ABSTRACT
This article aims to assess the impact of coronavirus (COVID-19) spread-prevention actions on water consumption, based on a case study in Joinville, Southern Brazil. Residential water consumption data, obtained through telemetry in two periods (before and after a governmental action imposing quarantine and social isolation), were analyzed. Complementarily, the analyses were also applied to the commercial, industrial and public consumption categories. For the analysis, Wilcoxon and Kruskal-Wallis non-parametric tests were applied and Prais-Winsten regression models were adjusted. The results of the Wilcoxon test show that there are significant differences between the analyzed periods, indicating a water consumption drop in the commercial, industrial and public categories, and an increase in the residential category. The regression model results confirm the effect of the restrictive actions in reducing consumption in non-residential categories. The results also indicate an increase in water consumption, which was steeper in apartment buildings than in houses, whether isolated or grouped in condominiums. A weak association was found between the variation in water consumption and the spatial distribution of buildings. Understanding water consumption related aspects is important to gather essential information to ensure the urban water supply system is resilient in a pandemic situation.
ABSTRACT
RESUMO O consumo racional de água é assunto de grande importância e abrangência atualmente, pois está diretamente ligado à qualidade de vida da sociedade e ao crescimento econômico das cidades. Nesse contexto, equipamentos hidrossanitários economizadores de água são opções existentes para a redução do consumo em edificações. Este trabalho teve o objetivo de quantificar o impacto da troca de equipamentos convencionais por economizadores no consumo de água em uma instituição de ensino superior. Além da troca dos equipamentos, procurou-se analisar a influência de outras variáveis, como temperatura diária e número de alunos. Para a realização da pesquisa foram instalados hidrômetros em um dos edifícios da instituição, de modo a medir o consumo isolado em bacias sanitárias, torneiras de lavatórios, torneiras de limpeza, mictórios e bebedouros. O estudo foi dividido em etapas, com leituras antes das intervenções e após a substituição dos equipamentos convencionais por equipamentos economizadores de água (torneiras de lavatório e válvulas de descarga) e o ajuste de vazão dos bebedouros. Para a análise estatística, utilizou-se um modelo de regressão linear múltipla que contou com o consumo como variável resposta e as trocas dos equipamentos, o número de alunos e a temperatura diária como variáveis explicativas. Os resultados obtidos revelam que a troca das torneiras foi significativa para o consumo total diário na edificação, com redução de 12,34%. Em análise individual dos equipamentos hidrossanitários, a troca apresentou-se significativa para a diminuição do consumo de água de cada tipo de equipamento.
ABSTRACT Water conservation is a matter of great importance. It is directly linked to the quality of life of society and the economic growth of cities. In this context, water saving plumbing fixtures are an option for reduction of consumption in buildings. This study aims to assess whether the replacement of ordinary plumbing fixtures with water saving ones in a University campus has an influence on water consumption. Besides the replacement of the plumbing fixtures, the influence of other variables such as temperature and number of students is analysed. Water meters were installed in one of the campus buildings in order to measure the isolated consumption in toilets, taps, urinals and drinking fountains. The study was divided in two stages: metering before the intervention and after the replacement of ordinary equipment with water saving devices (lavatory taps and toilets) and adjust of drinking fountains flow. For statistical analysis, a multiple linear regression model was used with consumption as the dependent variable and plumbing fixture replacement, number of students and daily temperature as the explanatory variables. The results show that the replacement of taps was significant for the total daily water consumption in the building, with 19.77% of reduction. According to an individual analysis of the plumbing fixtures, the replacement proved to be significant for the reduction of water consumption.
