Agricultural irrigation is the major water consumer in the Mediterranean region. In response to the growing pressure on freshwater resources, more efficient irrigation technologies have been widely promoted. In this study, we assess the impact of the ongoing transition from flood to drip irrigation on future hydroclimatic regimes under various climate change scenarios, with a particular focus on actual evapotranspiration and groundwater recharge in the Mediterranean region of Valencia, Spain. Hydroclimatic predictions for the near-term future (2020–2049) and the mid-term future (2045–2074) were made under two emission scenarios (RCP 4.5 and RCP 8.5) using a hydrological model that was forced with data from five GCM-RCM combinations and field-based irrigation volume and frequency observations. Our findings suggest that climate change could lead to statistically significant changes in the regional hydroclimatic regime despite projection uncertainties. Major changes include a statistically significant decrease in mean groundwater recharge of up to −6.6% under flood irrigation and −9.3% under drip irrigation and contrasting changes in mean actual evapotranspiration for flood and drip irrigation in the order of +1% and −2.1%, respectively. Since sustainably available water resources in the Valencia region are entirely allocated, the expected changes and associated uncertainties create a challenging context for future water management. Our simulations further indicate that, rather than climate change, the choice of irrigation technique may have a greater impact on actual evapotranspiration and groundwater recharge. Our findings therefore highlight the importance of considering both climate change and irrigation technique when assessing future water resources in irrigated Mediterranean agriculture.

中文翻译：

---

气候变化下从洪水到滴灌：对巴伦西亚（西班牙）地中海地区的蒸散量和地下水补给的影响

农业灌溉是地中海地区的主要用水户。为了应对对淡水资源日益增长的压力，已广泛推广了更有效的灌溉技术。在这项研究中，我们评估了从洪水到滴灌的持续过渡对各种气候变化情景下未来的水文气候制度的影响，特别关注西班牙巴伦西亚地中海地区的实际蒸散量和地下水补给量。在两种排放情景（RCP 4.5和RCP 8.5）下，采用水文模型，并根据来自五个GCM-G的数据，对近期（2020-2049）和中期（2045-2074）进行了水文气候预测。 RCM组合以及基于实地的灌溉量和频率观测。我们的发现表明，尽管预测存在不确定性，气候变化仍可能导致区域性水文气候体制发生统计上的重大变化。重大变化包括：在洪水灌溉下，平均地下水补给量在统计上显着下降，分别为-6.6％和在滴灌条件下下降-9.3％，与之相比，洪水和滴灌的实际实际蒸散量变化分别为+ 1％和-2.1％ ， 分别。由于瓦伦西亚地区的可持续可用水资源已全部分配，因此预期的变化和相关的不确定性为未来的水资源管理创造了充满挑战的环境。我们的模拟进一步表明，灌溉技术的选择而不是气候变化，可能对实际蒸散和地下水补给产生更大的影响。