SIMULATION MODELING TO DETERMINE SUITABILITY OF AGRICULTURAL LAND

Land suitability assesses the potential of land for a specific land us e. Traditionally, interactions between land characteristics and produc tivity are determined using qualitative methods. In contrast, a quanti tative land evaluation uses a biophysical model to estimate these inte ractions. This paper presents a comparison between a qualitative and q uantitative evaluation. Spatial coverages of soil, climate and topogra phy were compiled for approximately 2850 km(2) of a dryland cereal cro pping area in central Queensland, Australia. Model parameters that des cribe the soil were derived from soil survey data using surrogate meth ods. That is, no model calibration was used. The comparison of land su itability class and modelled yield showed that spatial modelling expla ined up to 80% of the variability in land suitability class. The resul ts in this paper have provided confidence in the use of modelling tech niques for land evaluation in Queensland, Australia.