Catalan Institute for Water Research - ICRA, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona, Catalonia, Spain; Fluvial Dynamics Research Group - RIUS, University of Lleida, Alcalde Rovira Roure 191, 25198 Lleida, Catalonia, Spain.
School of Geography and the Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, United Kingdom.
Sci Total Environ. 2016 Jan 1;540:144-57. doi: 10.1016/j.scitotenv.2015.07.005. Epub 2015 Jul 15.
This paper assesses annual and seasonal trends in runoff and sediment load resulting from climate variability and afforestation in an upland Mediterranean basin, the Ribera Salada (NE Iberian Peninsula). We implemented a hydrological and sediment transport distributed model (TETIS) with a daily time-step, using continuous discharge and sediment transport data collected at a monitoring station during the period 2009-2013. Once calibrated and validated, the model was used to simulate the hydrosedimentary response of the basin for the period 1971-2014 using historical climate and land use data. Simulated series were further used to (i) detect sediment transport and hydrologic trends at different temporal scales (annual, seasonal); (ii) assess changes in the contribution of extreme events (i.e. low and high flows) and (ii) assess the relative effect of forest expansion and climate variability on trends observed by applying a scenario of constant land use. The non-parametric Mann-Kendall test indicated upward trends for temperature and decreasing trends (although non-significant) for precipitation. Downward trends occurred for annual runoff, and less significantly for sediment yield. Reductions in runoff were less intense when afforestation was not considered in the model, while trends in sediment yield were reversed. Results also indicated that an increase in the river's torrential behaviour may have occurred throughout the studied period, with low and high flow events gaining importance with respect to the annual contribution, although its magnitude was reduced over time.
本论文评估了气候变化和造林在一个山地地中海流域（里贝拉萨拉达流域，伊比利亚半岛东北部）对径流量和泥沙负荷的年度和季节性变化趋势的影响。我们使用一个具有每日时间步长的水文和泥沙输移分布式模型（TETIS），使用 2009-2013 年期间在一个监测站收集的连续流量和泥沙输移数据进行了模型校准和验证。模型校准和验证后，使用历史气候和土地利用数据模拟了该流域 1971-2014 年的水沙响应。进一步使用模拟系列（i）在不同时间尺度（年度、季节性）上检测泥沙输移和水文趋势；（ii）评估极端事件（即低流量和高流量）贡献的变化；（iii）评估森林扩张和气候变化对应用恒土地利用情景观测到的趋势的相对影响。非参数曼肯德尔检验表明，温度呈上升趋势，降水呈下降趋势（尽管不显著）。年径流量呈下降趋势，而泥沙产量的下降趋势则不太明显。在模型中不考虑造林时，径流量的减少程度不那么强烈，而泥沙产量的趋势则相反。结果还表明，整个研究期间河流的湍急行为可能有所增加，低流量和高流量事件相对于年贡献的重要性增加，尽管其强度随时间减少。
