COMPUTER MODELING OF THE EFFECT OF REVEGETATION STRATEGIES ON SALINITY IN THE WESTERN WHEAT-BELT OF WESTERN-AUSTRALIA - 1 - THE IMPACT OF REVEGETATION STRATEGIES

The interactions between land, vegetation, and climate are highly comp lex and there are few demonstrations of the many potential combination s of treatments which could be used to combat dryland salinity. For th is reason, computer simulations are used. This is the first of 2 paper s that describe the results of computer modelling of revegetation stra tegies to reduce land and water salinisation in the western wheatbelt of Western Australia. A distributed parameter, physically based, cellu lar, 2-layer, mathematical model was used to simulate the effect of a variety of treatments. Modelling predicted that if current land use co ntinues, 40% of the cleared area will become saline. Modelling replace ment of the annual pasture with a deep-rooted perennial pasture or pri stine native vegetation prevented the onset of salinity, but block or alley treatments always left a significant residual saline area and se epage even at the highest density of revegetation modelled. Combining remnant vegetation in pristine condition, 60-m-spaced tree belts and d eep-rooted perennial pasture in mainly the upper mid-slope bays betwee n tree belts reduced saline land to 10% of the cleared area and seepag e volume to 30% of the untreated case. The second paper describes the impact of faults on treatment effectiveness.