Basin-wide planning requires tools and strategies that allow comparison of alternative pathways and priorities at relevant spatial and temporal scales. In this paper, we apply a hydroeconomic model–the Western Nepal Energy Water Model–that better accounts for feedbacks between water and energy markets, to optimize water allocations across energy, agriculture, municipal, and environmental sectors. The model maximizes total economic benefits, accounting for trade-offs both within and across sectors. In Western Nepal, we find that surface water availability is generally sufficient to meet existing and growing demands in energy and agricultural sectors; however, expansion of water storage and irrigation infrastructure may limit environmental flows below levels needed to maintain the full integrity of important aquatic ecosystems. We also find substantial trade-offs between irrigation in Nepal and satisfaction of the institutional requirements implied by international water-use agreements with the downstream riparian India. Similar trade-offs do not exist with hydropower, however. Model results and allocations are sensitive to future domestic and international energy demands and valuations.

流域范围的规划需要工具和策略，以便在相关的时空尺度上比较替代途径和优先重点。在本文中，我们应用了水力经济模型（尼泊尔西部能源水模型），该模型可以更好地说明水与能源市场之间的反馈，从而优化能源，农业，市政和环境部门之间的水分配。该模型将总经济收益最大化，并考虑了部门内部和部门之间的权衡。在尼泊尔西部，我们发现地表水的供应量通常足以满足能源和农业部门的现有需求和不断增长的需求；然而，蓄水和灌溉基础设施的扩大可能将环境流量限制在维持重要水生生态系统完全完整性所需的水平以下。我们还发现，尼泊尔的灌溉与满足与下游河岸印度的国际用水协议所隐含的体制要求之间存在着重大的权衡。但是，水力发电不存在类似的权衡取舍。模型结果和分配对未来的国内和国际能源需求和估值敏感。