Evaporation is generally regarded as the most significant loss mechanism from small agricultural reservoirs. As such it is imperative that the managers of such resources are informed as to the potential for water loss and any technologies that exist to mitigate this problem.
This thesis seeks to create both a passive and interactive evaporation information resource for water managers. It is postulated that by providing relatively accurate quantitative data, regarding site specific evaporation and evaporation reduction potentials, water managers will be more active and effective in evaporation control and implement superior management techniques of their resources. Additionally it is proposed that the shelterbelt is an effective evaporation retardation device in the Border Rivers Region of Queensland and New South Wales. Subsequently, through implementation of site-specific numerical data and shelterbelts, increases in farm yield from small landholders should be observed.
To test this hypothesis research has been undertaken in several fields. Data regarding evaporation theory, meteorological conditions and evaporation reduction technologies has been collected and collated from a variety of sources, such as research journals, established teaching literature and the Bureau of Meteorology. Additionally a questionnaire has been distributed to a target group of small water resource managers, predominantly farmers, regarding the usefulness of numerical data in decision- making.
Statistical methods have then been utilized to test the accuracy of existing predicative models for the geographical area in question. Additionally various sensitivity analyses have been undertaken to highlight the critical components of evaporation models.
This dissertation is presented with three sections of the proposed information resource, predominantly as a means of realizing the underlying premise of this thesis, i.e. provide a useable information resource for small water managers. Section I present’s a concentrated technical review of evaporation theory. Section II presents a review of evaporation reduction technologies and the underlying theory of shelterbelts. Section III presents the users manual for a set of interactive Microsoft Excel programs. These programs have been developed to enable water mangers to examine site-specific data for their situation and include a Potential Evaporation Calculator (PEC), a Shelterbelt Evaporation Reduction Potential toolkit (SHERPA) and an Economic Viability Modeller (EVM).
Conclusions have been drawn, based upon both statistical and empirical results. Firstly, the primary hypothesis, that an increase in evaporation management activity and effectiveness accompanies accurate numerical data for individual sites, is implied via the limited response to questionnaire feedback. Additionally anecdotal evidence of a positive correlation between implementing evaporation reduction technologies and increased farm yields exists. Due to time and information dissemination constraints, the above two premises cannot be statistically and unequivocally verified. However these points provide excellent starting positions for further research.
The second premise that the shelterbelt is an effective evaporation reduction technology within this studies geographic scope is theoretically verified via results derived from the Microsoft Excel program suite.
Though extensive research into evaporation, evaporation management and historical meteorological data this paper has provided an accurate information resource in the Border Rivers region of South West Queensland and North West New South Wales.