Assessing the impact of Sars-CoV-2 on water consumption in São Paulo State, Brazil

The pandemic caused by Sars-CoV-2 in 2020 led to a significant change in behaviors, mainly because of the quarantine to avoid the spread of the virus. Measures affected both economic activities and citizens´ behaviors as they developed more intense hygiene habits to avoid contamination and switched to home office. These exceptional behaviors also affect the way that water is consumed and need to be fully understood to manage supply systems. Therefore, this study aims to investigate changes in residential and commercial water consumption in 31 municipalities in the State of São Paulo during the Sars-CoV-2. To do this, the expected consumption for 2020 was forecasted using the Holt-Winters Multiplicative method and compared to the data observed for the same period. In addition, we compared monthly records of new contaminations to establish a comparison between the number of infections and changes in water consumption. The results show an average difference between forecasted and observed consumption equal to + 6.23% and -18.59% for residential and commercial activities, respectively. For residential consumption, consumption per capita increased at the rate of 8.44 L.person-1.day-1. The changes in consumption seem to be a consequence of hygiene habits, social distancing and the closing of non-essential services in commerce.2020年由严重急性呼吸综合征冠状病毒2型（Sars-CoV-2）引发的新冠疫情，因旨在阻断病毒传播的防疫隔离措施，对民众行为模式造成了显著改变。相关防疫措施不仅冲击了经济活动，更促使市民养成更为严格的卫生防护习惯以规避感染风险，同时推动了居家办公模式的普及。此类非常规的行为变化同样对饮用水消费模式产生了影响，因此全面厘清此类变化对于供水系统的运维管理至关重要。 为此，本研究旨在探究2020年圣保罗州31个自治市的居民与商业用水消费变化情况。研究采用霍尔特-温特斯乘法模型（Holt-Winters Multiplicative method）对2020年的预期用水量进行预测，并将其与同期实际观测的用水数据进行对比。此外，本研究还比对了月度新增感染病例记录，以分析感染人数与用水消费变化之间的关联。 研究结果显示，居民与商业用水的预测值与实际观测值的平均偏差分别为+6.23%与-18.59%。就居民用水而言，人均日用水量提升了8.44升·人⁻¹·天⁻¹。此类用水消费变化，可归因于卫生习惯调整、社交距离防疫措施的实施以及商业非必需服务的关停。