ABSTRACT

The DSSAT4.7-CERES model was employed to simulate plant-water nexus conditions in the future of Mazandaran province in Iran, using ensemble outputs of various GCMs and emission scenarios with LARS-WG 5.5 in the time period 2010–2100. The results showed during the 21^st century, maize water requirement is expected to be reduced by 3.3–14.1%. Under climate change scenarios, both negative and positive changes in crop yield are projected, between −37.4 and 36.1%, which consequently results in a 5.1–27.2% reduction in water use efficiency (WUE) in the future periods. Deficit irrigation (DI) with 25% reduction in irrigation water depth (DI₇₅) lead to a moderate reduction of 4.3–5.5% in WUE, but WUE was highly reduced under DI₅₅. While early planting may reduce WUEs by 0.4–17%, late planting almost resulted in improved WUE, especially under DI₇₅. Less frequent irrigation significantly reduces actual evapotranspiration, which consequently resulted in improved WUE by 0.57– 42.47%. In conclusion, the integrated assessment reveals that DI₇₅, with an irrigation interval of 5 days, together with a 20 days delay in cropping date of maize in Mazandaran province, may be considered as an effective adaptation solution, when considering both food and water security.

摘要

DSSAT4.7-CERES 模型用于模拟伊朗马赞达兰省未来的植物-水关系条件，使用各种 GCM 的集合输出和 LARS-WG 5.5 在 2010-2100 年期间的排放情景。结果显示，21^世纪玉米需水量预计将减少3.3-14.1%。在气候变化情景下，预计作物产量会出现负和正变化，介于 -37.4% 和 36.1% 之间，因此导致未来期间用水效率 (WUE) 降低 5.1% 至 27.2%。灌溉水深 (DI ₇₅ ) 减少 25% 的亏缺灌溉 (DI) 导致 WUE 适度减少 4.3-5.5%，但在 DI _{55下 WUE 大大减少}. 虽然早期种植可以将 WUE 降低 0.4-17%，但后期种植几乎可以改善 WUE，尤其是在 DI ₇₅下。减少灌溉频率会显着降低实际蒸散量，从而将 WUE 提高 0.57-42.47%。总之，综合评估表明，在考虑粮食和水安全时，DI ₇₅（灌溉间隔为 5 天，加上马赞达兰省玉米种植日期延迟 20 天）可被视为有效的适应解决方案.