A decision support system for predicting seasonal rainfall variations in sub-humid and semi-arid high country areas

Abstract

The variable seasonal pattern of pasture production is dominantly influenced by rainfall in the semiarid and sub-humid high country regions. A decision support system for predicting seasonal rainfall has been developed and tested using the rainfall data from 14 sites in the semi-arid, sub-humid and humid high country zones. The prediction system improves the chances of making a correct or incorrect but conservative risk management decision from 50:50 to as much as 92:8 dependent on the site's weather characteristics and the length of rainfall records available. The system provides support for risk management decisions such as whether to employ the buffers of stocking rate adjustments and feed conservation measures usually present in most high country farming systems to cope with the variability in seasonal pasture growth. The method has particular applicability in the semi-arid and subhumid areas of the inland basins and foothills and the mid Waitaki area. Keywords: decision support, high country, rainfall, risk management, semi-arid, sub-humid