Department of Hydraulic Engineering, State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China.
ZJU-UIUC Institute, International Campus, Zhejiang University, Haining 314400, China.
Sci Total Environ. 2020 Aug 1;728:137996. doi: 10.1016/j.scitotenv.2020.137996. Epub 2020 Mar 17.
The Water-Food-Energy nexus study identifies developmental challenges and trade-offs present along the transboundary river basins. Intensive reservoir development for hydropower production impacts existing actors in the Lancang-Mekong River Basin. Concerns from these stakeholders highlight three major trade-offs that occur between hydropower and irrigation (HP-AG), hydropower and fisheries (HP-F), and irrigation and fisheries (AG-F). Dam construction has an impact not only on power production but also on ecosystems and ultimately the livelihood of people. In this study, we quantify the effects of reservoir operation on hydropower generation, irrigated crop production and fisheries yield in the Tonle Sap lake through a novel hydro-economic model at the whole basin scale. Our main finding is that trade-offs can be turned into synergetic opportunities. First, the dam operation can increase water availability for irrigation without severely harming hydropower production, raising irrigated crop revenue by 49% and reducing crop losses during droughts by 30%. Second, eco-friendly management increases fisheries yield by up to 75%, but decreases both irrigated crop production (-48%) and power production (-17%). Reservoirs can, therefore, benefit the whole basin by releasing more water in months with high irrigation demand (April and December) and by minimizing the adverse effects of flow fluctuations on the livelihood of farmers and fishers living downstream. Our results also reveal the overlooked trade-off between irrigated agriculture and fisheries. Cross-sectoral and transboundary partnerships should strengthen stakeholder participation in decision-making. Local solutions such as enhanced reservoir operation can respond to the broader global issue of natural resource trade-offs and sharing. Our alternative narrative enhances the dialogue about fair and efficient water use among Mekong riparian countries.
水-粮-能关系研究确定了跨界流域存在的发展挑战和权衡取舍。为了水力发电而密集开发水库会对澜沧江-湄公河流域的现有行为体产生影响。这些利益相关者的关切突出了水电与灌溉（HP-AG）、水电与渔业（HP-F）以及灌溉与渔业（AG-F）之间存在的三大权衡取舍。大坝建设不仅对电力生产产生影响，还会对生态系统产生影响，并最终影响到人民的生计。在本研究中，我们通过全新的全流域水经济模型来量化水库运行对洞里萨湖水电发电、灌溉作物生产和渔业产量的影响。我们的主要发现是，权衡取舍可以转化为协同机会。首先，大坝运行可以增加灌溉用水供应，而不会严重损害水电生产，从而使灌溉作物收入增加 49%，减少干旱期间的作物损失 30%。其次，生态友好型管理可使渔业产量提高多达 75%，但会减少灌溉作物生产（-48%）和电力生产（-17%）。因此，水库可以通过在灌溉需求高的月份（4 月和 12 月）释放更多的水，并最大限度地减少水流波动对下游农民和渔民生计的不利影响，使整个流域受益。我们的研究结果还揭示了灌溉农业和渔业之间被忽视的权衡取舍。跨部门和跨界伙伴关系应加强利益相关者参与决策。增强水库运行等地方解决方案可以应对全球自然资源权衡取舍和共享的更广泛问题。我们提供的替代方案加强了湄公河沿岸国家之间关于公平和高效用水的对话。
