Critical factors affecting the adoption of airborne geophysics for management of dryland salinity

Abstract

Airborne geophysics has been developing as a tool for catchment management for at least 15 years. However, today its value is being debated, as the data have largely failed to alter either the current trajectory of salinity, or the plans that have ensued, in any catchment in which it has been used. Why, when we acknowledge that the technology has developed and now provides unparalleled insight into soils, geology, and regolith structure, have we failed to use it successfully, and how can we deliver on the expectations pent up in Government and the community? Several significant projects have driven the environmental and geophysical communities closer to answering these questions. Increasing demand by landholders and land managers to understand what is happening underground, and what actions are required for its management, have further encouraged the need for geophysical systems. Collaboration by governments and industry has helped expand the 'market' for salinity-related geophysics. The National Airborne Geophysics Project 1997?1999 (George et al., 1998) was the first formal, national review of its application. This application-focused research tested the ability of the geophysical systems to provide specific information products for use at paddock level, and drew several favourable conclusions. In this paper, we argue that the answer to the geophysical data dilemma pivots on the reality that a gulf remains between the collection and interpretation of the data and effective application of the interpretations to land-management problems. We review some of the issues behind the application of current airborne geophysical systems to salinity and catchment management. The relative costs and benefits of the various data sets suggest that airborne geophysics is likely to be effective and economic for land management where: there is relatively poor existing natural resource data; the options for salinity management are understood and cost-effective; specific management actions can be derived from the geophysics; and both off-site and on-site benefits are high. This benefit may be further enhanced where the geophysical data, especially radiometrics, can facilitate implementation of precision agriculture methods. Finally, we suggest that a user-needs analysis of informed farmers and land-use planners would ensure the targeted supply of information products based on airborne geophysics.