Editorial

Abstract

As 2017 begins, it is clear that whatever policy direction world leaders take with regard to infrastructure and investment, there is more uncertainty around these areas that there appeared to be this time last year. With unanswered questions following the Brexit vote and its aftermath -not to mention the imminent change in administration in the USA -it is more important than ever that engineers, practitioners and researchers work together to continue to assess the impacts of new technologies and what they mean for the way civil engineers go about their business. The spirit of inquiry, systematic research and peer review as enshrined in the processes followed by all of the ICE Proceedings journals ensures that we are well placed to test any new technologies that are proposed and to maximise the benefits to designers and contractors. The present issue contains a further set of peer-reviewed articles that draw on a range of theories and cover a range of topics.It is a testament to the enduring importance and attractiveness of open channel flows and their measurements that of the four papers contained in this issue are directly related to open channel flows and developing the work laid out in the standard texts on this issue such as Chow (1959) andFrench (1985). Indeed, at the time these works were written it was well understood that the theory contained in them would develop as better measurement techniques became available and as the demands for leaner and more ambitious designs grew. It also goes to show that the problems we research in this branch of civil engineering are not usually 'new' in the sense that, for example, we still need to construct bridges and other river crossings, which generally affect open channel flow and cause changes in flow regime. In all four papers the authors acknowledge this explicitly and also make use of experimental results to support their findings.There is no doubting the value of studies like that of Deshpande and Kumar (2017), which make use of large flume facilities -in India in this case -to investigate the behaviour of sediments in open channels. Here, as in all four papers, the authors collected results in a large-scale experimental facility over long periods of time -it must also be recognised that good quality data sets only become available when researchers have had access to a particular resource or piece of equipment over a long period. The problem in this case is complex: what happens to a channel cross-section when seepage is taken into account alongside a streamwise flow regime, and the authors show that traditional models put forward by others must be adapted to account for the amount of bed seepage, which may be considerable in some real-world cases (the paper contains a startling statistic that up to 45% of the flow may be lost in some cases to seepage). It is really only when we use large-scale physical models in a controlled environment such as a hydraulic laboratory that the full extent of the research questions becomes obvious. This contribution clearly has i...