A review of climatic impacts on water main deterioration

Watermains are both directly and indirectly affected by climatic conditions such as temperature and precipitation. Research has been conducted to understand and model the effects of climatic conditions on watermain breaks. However, review studies to map the knowledge development in this area, to identify key achievements and limitations of previous studies are missing, and are addressed in this study. This review uses a mixed systematic and scientometric analysis to establish the research trends, contributions, methods, and covariates employed by previous studies related to climatic impacts on watermain deterioration. Web of Science and Scopus database is primarily employed to identify 70 relevant studies on the subject matter. These studies have been mostly conducted by institutions based in Canada, USA, and Europe. There is a general lack of collaboration among different institutions conducting research in this area. Studies in the subject matter are published from 1982 onwards, however, significant number of studies per year can only be noticed from 2005 onwards. Previous studies have been mostly focused on the modelling of watermain failure and have used statistical methods, and data-driven and artificial intelligence (AI) approaches for failure modelling of watermains under climatic conditions. For testing and validation of research data, studies have employed correlation analysis, performance evaluation metrics, and descriptive statistics. Typically, climate-related variables used in studies include temperature, moisture, and precipitation. Reviewed studies have considered cold (66%), hot (31%), and dry (13%) climatic conditions. Studies have investigated watermains made of metal (56%), plastics (43%), and Concrete and Asbestos cement (31%). Future studies are recommended to consider Data-driven and AI approaches in research design; pay attention to watermains in climatically vulnerable and massively populated regions; and consider climate risk assessment and the impact of climate change and extreme weather conditions on watermains.The authors commend the support of the Innovation and Technology Fund (Innovation and Technology Support Programme (ITSP)) under grant number ITS/033/20FP , and the Water Supplies Department of Hong Kong

A Review of COVID-19-Related Literature on Freight Transport: Impacts, Mitigation Strategies, Recovery Measures, and Future Research Directions

The COVID-19 pandemic has caused significant disruptions in the freight transport sector. The number of studies on the impact of COVID-19 on freight transport and possible mitigation strategies are growing. However, a systematic and comprehensive review highlighting the research themes, main findings, research methods, and future research directions of these studies remains scarce. Therefore, this study presents a mixed review comprising scientometric and systematic reviews to cover these research gaps. Results show that 68 studies have been published on this topic since the beginning of 2020 and that they cover three main themes: the impacts of COVID-19 on freight transport, mitigation strategies, and recovery during and after COVID-19. In addition, we describe the research methods, main findings, and possible research directions in each of them. Thus, the findings of our work present both theoretical and practical analyses of COVID-19-related research on freight transport and provide important future research directions in this domain