Incorporating geological effects in modeling of revegetation strategies for salt-affected landscapes

This paper synthesizes results of research into the impact that major fault s have on dryland salinity and the development of revegetation treatments i n the wheatbelt of Western Australia. Currently, landscape planning does no t routinely incorporate geology, but this research shows that faults can ha ve a dramatic impact on land and stream salinization and on the effectivene ss of revegetation treatments, and evidence exists that other geological fe atures can have a similar influence. This research shows that faults can be identified from airborne magnetic data, they can be assigned a characteris tic hydraulic conductivity based on simple borehole tests, and four other g eological features that are expected to affect land and stream salinity cou ld be identified in airborne geophysical data. A geological theme map could then be created to which characteristic hydraulic conductivities could be assigned for use in computer groundwater models to improve prediction of th e effectiveness of revegetation treatments and thus enhance the landscape p lanning process. The work highlights the difficulties of using standard sampling and statist ical techniques to investigate regional phenomena and presents an integrate d approach combining small-scale sampling with broad-scale observations to provide input into a modeling exercise. It is suggested that such approache s are vital if landscape- and regional-scale processes are to be understood and managed. The way in which the problem is perceived (holistically or pi ecemeal) affects the way treatments are designed and their effectiveness: p ast approaches have failed to integrate the various scales and processes in volved. Effective solutions require an integrated holistic response.