Instituto Pirenaico de Ecología, Consejo Superior de Investigaciones Científicas (IPE-CSIC), Campus de Aula Dei, Avenida Montañana 1005, 50059, Zaragoza, Spain.
Instituto Pirenaico de Ecología, Consejo Superior de Investigaciones Científicas (IPE-CSIC), Campus de Aula Dei, Avenida Montañana 1005, 50059, Zaragoza, Spain.
Environ Res. 2020 Dec;191:110158. doi: 10.1016/j.envres.2020.110158. Epub 2020 Sep 3.
An analysis of long-term databases with information on precipitation and discharge records was undertaken to characterize the temporal structure response of four experimental catchments, located in the Central Spanish Pyrenees, with a gradient of land-cover (from a relatively pristine forested catchment, through an abandoned cultivated catchment with progressive plant recolonization, to an afforested catchment and ending with a degraded badlands catchment). Precipitation and discharge records are non-stationary and the wavelet transform methodology was thus applied to perform a temporal scale-by-scale analysis of each catchment response to the hydroclimatic characteristics of the area. This temporal decomposition analysis illustrates how land-use and land-cover legacy control the temporal distribution of flow events occurring at different and non-similar time-scales, thus reflecting the timing, variability and physical mechanisms of water storage/transport in each catchment. Intra-annual and annual time-scales are led by climatological characteristics of the catchment sites (seasonal patterns of mountainous Pyrenees catchments). Multi-year scale is mainly shaped by land-cover and land-use legacy. Badlands catchment, with its large proportion of bare land, shows a discharge response closely synchronized with precipitation patterns for all time-scales. On the contrary, for the forested catchment the global hydrological response is mainly governed by the multi-year time-scale. Afforested catchment and abandoned cultivated catchment, which move towards a pristine forest response, are impacted by the former grazing and agriculture activities and intra-annual temporal variability still play a major role on the global discharge response of the catchment. This suggests that vegetated catchments located in the same region can show hydrological responses at different time-scales to the same climatic input. We argue that differences in land-cover and historical land-use changes are not only valuable to understand the current discharge temporal behaviour, but they will also play a significant role in characterizing the future catchment dynamics due to changing climate conditions.
对具有降水和径流量记录信息的长期数据库进行了分析，以描述位于西班牙中比利牛斯山脉的四个实验流域的时间结构响应，这些流域的土地覆盖类型存在梯度变化（从相对原始的森林流域，经过逐渐植物再造林的废弃耕地流域，到森林流域，最后到退化的荒地流域）。降水和径流量记录是非平稳的，因此应用小波变换方法对每个流域对该地区水文气候特征的时间尺度响应进行了尺度分析。这种时间分解分析说明了土地利用和土地覆被如何控制不同且非相似时间尺度上的水流事件的时间分布，从而反映了每个流域的储水/输运的时间、变异性和物理机制。年内和年际时间尺度由流域站点的气候特征（山区比利牛斯流域的季节性模式）主导。多年时间尺度主要由土地覆被和土地利用的遗留物塑造。由于大部分为裸地，荒地流域的径流量响应与所有时间尺度的降水模式紧密同步。相反，对于森林流域，全球水文响应主要受多年时间尺度的控制。正在向原始森林响应转变的森林流域和废弃耕地流域，受到前放牧和农业活动的影响，年内时间变异性仍然对流域的全球径流量响应起着重要作用。这表明位于同一地区的植被流域可以对同一气候输入表现出不同的时间尺度的水文响应。我们认为，土地覆被和历史土地利用变化的差异不仅对于理解当前的排放时间行为很有价值，而且由于气候变化条件，它们在表征未来流域动态方面也将发挥重要作用。
