Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, Grindelberg 5, 20144, Hamburg, Germany.
Institute of Soil Science, Center for EarthSystem Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany.
Environ Monit Assess. 2024 Nov 30;196(12):1282. doi: 10.1007/s10661-024-13405-4.
Nepal is expanding its irrigation facilities as an adaptive measure to climate change; however, the current canal conveyance efficiency (CCE) is low with significant water losses. In this study, we assess the potential impact of increasing CCE on the productivity of rice, maize, and wheat under different climate change scenarios (SSP1-2.6, SSP3-7.0, and SSP5-8.5), utilizing three bias-adjusted general circulation models. The study simulates potential yields at ecoregion levels for two periods: near future (2023 to 2050) and end-century (2075 to 2100). Management scenarios include the following: (1) business as usual, (2) CCE at 30%, (3) CCE at 50%, and (4) CCE at 70%. The results indicate that increasing CCE to 30%, coupled with expanded irrigated areas and adjusted fertilization rates, could boost yields by three tons per hectare across all three crops at the national level. Further increasing CCE to 50% could yield additional increases of up to 0.6 t/ha of maize and 1.2 t/ha of rice in the terai region. A CCE of 70% results in further increases of up to 2.1 t/ha of rice and 1.2 t/ha of maize. The benefits of improved CCE vary by location, with the subtropical terai region experiencing the most and the mountain regions showing the least. We conclude that there is potential to increase yields by increasing CCE to 70% in the terai region, 50% in the hill region, and 30% in the mountains. Wheat appears to benefit the least from improved CCE. This work highlights efficient irrigation as a reliable adaptive measure for future climate change in Nepal.
尼泊尔正在扩大灌溉设施，作为适应气候变化的措施；然而，目前的渠道输水效率（CCE）较低，存在大量水资源损失。在本研究中，我们评估了在不同气候变化情景（SSP1-2.6、SSP3-7.0 和 SSP5-8.5）下，通过三种经偏差调整的通用环流模型提高 CCE 对水稻、玉米和小麦生产力的潜在影响。本研究在生态区水平上模拟了两个时期的潜在产量：近期（2023 年至 2050 年）和本世纪末（2075 年至 2100 年）。管理情景包括以下几种：（1）按现状，（2）CCE 为 30%，（3）CCE 为 50%，和（4）CCE 为 70%。结果表明，将 CCE 提高到 30%，加上扩大的灌溉面积和调整的施肥率，可能会使全国所有三种作物的单产提高 3 吨/公顷。进一步将 CCE 提高到 50%，可能会使台地地区的玉米和水稻的单产分别增加 0.6 吨/公顷和 1.2 吨/公顷。将 CCE 提高到 70%，会使水稻和玉米的单产分别增加 2.1 吨/公顷和 1.2 吨/公顷。提高 CCE 的效益因地点而异，亚热带台地地区受益最大，山区受益最小。我们得出结论，在台地地区将 CCE 提高到 70%、在丘陵地区提高到 50%、在山区提高到 30%，可以提高产量。小麦似乎从提高 CCE 中获益最少。这项工作强调了高效灌溉作为尼泊尔未来应对气候变化的可靠适应措施。
