Sustainable irrigation planning under increasing water scarcity requires quantitative optimization tools to balance land and water resources. This study develops a linear programming (LP) -based framework to determine optimal cropping patterns under variable seasonal water availability in three irrigation projects in Lao PDR: Nam Tong 2 (1000 ha; ≈48. 16 million m3 (MCM) ), Nam Hin (80 ha; ≈0. 73 MCM), and Xe Salalong (1530 ha; ≈30. 80 MCM). Six major crops were analyzed for each project, with crop water requirements ranging from 4000 to 12, 000 m3 ha−1 and gross revenues from 1200 to 41, 322 US ha−1. Eight irrigation scenarios were constructed by combining land suitability (suitable vs. unsuitable), crop water requirement levels, and gross revenue assumptions. The model maximizes total gross revenue subject to seasonal water and land constraints. The results indicate that under limited water availability (e. g. , 5. 35–6. 20 MCM in Nam Tong 2), crops with lower water demand (≤6000 m3 ha−1) and higher economic return per unit of water are prioritized, improving water-use efficiency. As water availability increases, high-value but water-intensive crops expand until land suitability becomes the dominant constraint. Expanding irrigation on unsuitable land produces diminishing economic returns. The framework enhances the realism of irrigation planning and supports economically efficient, water-sustainable crop allocation in water-scarce regions.
Phomphakdy et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: