As well as the reporting of research findings, the purpose of a learned journal is to generate comment and discussion. In this issue of Water Management we have one such contribution (Horritt et al., 2011), generated by comments on an earlier paper (Horritt et al., 2010). This discussion expands on the earlier paper to explain further some aspects of the tests and to remove some ambiguities in the original. It shows that model construction is not the straightforward task that some believe it to be (not including the authors concerned), particularly when modelling the natural environment.
The full papers in this issue cover a wide range of applications, but unlike the discussion paper the majority use experimental methods. It is encouraging to see papers on good experimental investigations as they are becoming increasingly rare owing to the cost of the necessary facilities.
There is one full paper in this issue that does not use experimental methods. Bozorg Haddad et al. (2011) present a method for optimising reservoir operations that appears to be preferable to genetic algorithms through their use of the optimal solution to generate further possible solutions. This is undertaken by drawing an analogy to honey-bee mating. It presents a fascinating example of how mimicking the natural world can help in engineering.
The first experimental paper examines local scour and how to predict it (Amini et al., 2011). This is a vital issue in most countries in order to protect key infrastructure from damage. In order to test a new method for predicting scour, a set of experimental measurements are obtained. This new method appears to hold promise but as the authors observe, more validation is necessary. This opens up a challenge for other researchers.
There is increasing focus on flooding caused by intense rainfall in urban areas, an issue that will become more important with increased climate variability and urbanisation. The paper by Gómez and Russo (2011) examines how to improve the estimate of the hydraulic efficiency of drain inlets, which are a key part of the urban drainage system. A series of measurements at 1:1 scale are presented and used to validate the new methodology. This methodology is applicable to a wide range of inlet designs and should prove of practical use.
The final experimental paper (Omid et al., 2011) examines the effect of sediment on hydraulic jump characteristics. Given the highly turbulent nature of hydraulic jumps and the significant energy dissipation involved, they are often accompanied by significant scour and this factor should be considered in design. The paper presents results across a broad parameter range and draws interesting and relevant conclusions.
