Profiting from the climate prophets

Making seasonal climate forecasts available to farmers in Indonesia is contributing to better water-resource management

Many Australian and Asia-Pacific farmers grow their crops and raise their livestock in an uncertain climate, marked in particular by large variations in rainfall from season to season.

It is in this context that scientists from Australia and Indonesia have taken up the challenge to determine how seasonal climate forecasting can lead to better irrigation-system management in Lombok, Indonesia. Lombok has three distinct geographical zones. The western zone gets the most water, but has little agricultural land. The central zone, with moderate rainfall, has the most agricultural land, while the southern and eastern area is dry. Water for the drier zones comes from irrigation channels out of the river in the west, with seasonal and inter-annual rainfall influenced by the El Niño-Southern Oscillation. In normal years this system is sufficient, but in El Niño years there is virtually no flow in these channels.

Dr Yahya Abawi, from the Queensland Climate Change Centre of Excellence in Toowoomba heads the Australian component of this ACIAR-funded project. He and his team are working with Indonesian project leader Professor Mansur Ma'shum and his colleagues from the University of Mataram in Lombok. Together they are developing models of water availability throughout Lombok's irrigation system, taking into account different climate, water, land and institutional constraints. They hope a RAINMAN software package, designed to help Australian farmers construct their individual seasonal forecasts, will lead to better prediction of stream flows during the irrigation season. This is important for effective water allocation decisions, especially in regions where there is virtually no water storage.

Dr Abawi notes that the research has provided the tools on which to base optimal cropping decisions. ‘But I recognise that social, cultural and policy issues often need to be addressed before the science of seasonal climatic forecasting is acceptable to farmers and water managers,' he says. ‘We must also bear in mind that educational levels may influence the farmers' ability to adopt such innovations. Another consideration that may influence decisions is the enduring tradition of rice-growing, which makes farmers more reluctant to try alternative crops.'

The Indonesian team members have now introduced the project outputs to farmer groups, field officers and government agencies in parts of Lombok. They too are conscious that farmers may be reluctant to change cropping patterns solely on the basis of climate forecast information, since their need to rely on crops grown on quarter-hectare farms (the average size in Lombok) makes them very vulnerable to any crop failure. Nevertheless the Indonesian scientists concur with Dr Abawi, who believes it is worth persevering to counter this reluctance.

By Janet Lawrence