干旱区生态环境知识资源中心

Irrigated agriculture is put under simultaneous pressure to supply the needs of a fast growing population and to release water for other, higher valued uses. In this context, solutions have to be devised to make a substantially more efficient and productive use of water in irrigation. This paper introduces a new irrigation model, OASIS (Options Analysis in Surface Irrigation Systems), which was developed to conceptualize and test irrigation interventions in a medium to large-scale irrigation system. OASIS integrates recycling and captures all the main factors of the water balance, including non-process depletion from fallow lands and non-crop vegetation. Based on its innovative skills, the model allows proper quantification of water use efficiency, productivity and equity under actual or hypothetical conditions of land use, infrastructure and water management. The main outcomes of the OASIS model application in the Bojili Irrigation District (BID), a large-scale irrigation scheme located in China's lower Yellow River basin, are presented. The analysis undertaken emphasizes the critical importance of properly accounting for the capture and recycling of irrigation return flows to develop a meaningful picture of how water is being used. Ultimately, this analysis suggests that integrated modelling tools like OASIS can bring very valuable support to identify opportunities and means to improve water use efficiency, productivity and equity in water-short areas such as the Yellow River basin.