Development of a smart monolayer application system for reducing evaporation from farm dams: introductory paper

Abstract

Chemical monolayer films are potentially an economical low-impact means of reducing evaporative loss from farm water storages. However, their performance can be highly variable as they are affected by climatic and environmental factors: principally wind, wave action and bio-degradation. Some of this observed variability is associated with the monolayer materials themselves and their interaction with the water-surface physics and biology, but the fact that they are only a few nanometres thick means that a very small amount of material has to be distributed over a very large area. Therefore, appropriate and timely autonomous application of monolayer, with regard to prevailing (and changing) wind conditions on-site, is required. Although a number of autonomous application systems for monolayer already exist, none has proved overly successful. It is argued that while this is in part due to sub-optimal performance of monolayer materials, it is also due in large measure to inaccuracies and/or inappropriate design in both application systems and particularly application strategies, which are not adaptive to the prevailing environmental conditions. Therefore a control system is being developed to adaptively and spatially vary monolayer application rates according to changing conditions monitored on-site. This will form part of an autonomous electromechanical system for the optimal application and spreading of any given chemical monolayer. This paper reports progress towards this objective; firstly by evaluation of the design requirements for automated systems at a range of spatial scales; and secondly via the construction of a first “pre-prototype” to act as an evaluation platform and concept demonstrator.