Abstract The increase in aridity and torrential events in semiarid areas predicted by the Intergovernmental Panel on Climate Change is expected to significantly affect their hydrological response and thus their associated nonpoint source pollution and erosive dynamics. This study quantifies rainfall-runoff patterns in a 6.1-ha olive orchard microcatchment in Southern Spain, representative of a marginal farm, to determine the impact of extreme events under different theoretical climate change scenarios. To this end, the physically based distributed hydrological model WiMMed (Watershed Integrated Management in Mediterranean Environments) was implemented, calibrated, and validated with experimental data throughout the study period (2005–2012). The root mean square error values for hourly runoff and flows derived from calibration and validation were approximately 1 and 0.3 mm s−1, respectively. An increase in mean temperatures of between 1.6°C and 3.9°C, a decrease in rainfall of between 13.7% and 26.6%, and larger torrential events were simulated in this study following possible climate change scenarios. The results revealed the nonlinear and complex interactions of the different processes conditioning the water balance due to opposite tendencies of rainfall decrease and the increase in temperature and rainfall intensity. The most significant change was found in the scenario that simulated an increase in the torrential character of the events. A mean runoff coefficient of over 0.6 was obtained in the catchment, which should be considered in future aspects of water management.

中文翻译：

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理论气候变化情景下半干旱橄榄园微流域的水文响应

摘要 政府间气候变化专门委员会预测的半干旱地区干旱和暴雨事件的增加预计将显着影响其水文响应，从而对其相关的非点源污染和侵蚀动力学产生重大影响。本研究量化了西班牙南部一个 6.1 公顷橄榄园微流域（代表边缘农场）的降雨径流模式，以确定极端事件在不同理论气候变化情景下的影响。为此，在整个研究期间（2005-2012 年）实施、校准和验证了基于物理的分布式水文模型 WiMMed（地中海环境中的流域综合管理）的实验数据。从校准和验证得出的每小时径流和流量的均方根误差值分别约为 1 和 0.3 mm s-1。本研究根据可能的气候变化情景模拟了平均气温升高 1.6°C 至 3.9°C、降雨量减少 13.7% 至 26.6% 以及更大的暴雨事件。结果表明，由于降雨量减少和温度和降雨强度增加的相反趋势，调节水平衡的不同过程之间存在非线性和复杂的相互作用。在模拟事件的暴雨特性增加的场景中发现了最显着的变化。在流域中获得了超过 0.6 的平均径流系数，这应在未来的水管理方面加以考虑。