Insights into the water mean transit time in a high-elevation tropicalecosystem
Insights into the water mean transit time in a high-elevation tropicalecosystem
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DOI：
10.5194/hess-20-2987-2016
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发表时间：
2016-07
影响因子：
6.3
通讯作者：
G. Mosquera;Catalina Segura;K. Vaché;D. Windhorst;L. Breuer;P. Crespo
中科院分区：
文献类型：
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作者：
G. Mosquera;Catalina Segura;K. Vaché;D. Windhorst;L. Breuer;P. Crespo
抽象。本研究主要探讨热带高海拔生态系统（湿安第斯帕拉莫）中水分的平均渡越时间（MTT）及其空间变异性。研究地点是位于厄瓜多尔南部的茹鲁凯河生态水文观测站（7.53平方公里）。使用考虑五个渡越时间分布（TTD）函数的集总参数模型来估计稳态条件下的MT（即，基流MTT）。我们使用了一个独特的数据集的δ 18 O同位素组成的降雨和径流水样品收集了3年（2011年5月至2014年5月）的嵌套监测系统的流。MTT和景观（土壤和植被覆盖，地质和地形）和水文（径流系数和比流量）变量之间的线性回归被用来探索控制MTT的变化，以及平均电导率（MEC）作为一个可能的代理MTT。结果表明，指数TTD函数最好地描述了该网站的水文，表示一个相对简单的过渡，从降雨水的溪流通过有机层的湿paramo土壤。河流的MTT相对较短（0.15-0.73年，53-264天）。回归分析显示，流域平均坡度与MTT呈负相关（R2 = 0.78，p
Abstract. This study focuses on the investigation of the mean transit time (MTT) of water and its spatial variability in a tropical high-elevation ecosystem (wet Andean paramo). The study site is the Zhurucay River Ecohydrological Observatory (7.53 km2) located in southern Ecuador. A lumped parameter model considering five transit time distribution (TTD) functions was used to estimate MTTs under steady-state conditions (i.e., baseflow MTT). We used a unique data set of the δ18O isotopic composition of rainfall and streamflow water samples collected for 3 years (May 2011 to May 2014) in a nested monitoring system of streams. Linear regression between MTT and landscape (soil and vegetation cover, geology, and topography) and hydrometric (runoff coefficient and specific discharge rates) variables was used to explore controls on MTT variability, as well as mean electrical conductivity (MEC) as a possible proxy for MTT. Results revealed that the exponential TTD function best describes the hydrology of the site, indicating a relatively simple transition from rainfall water to the streams through the organic horizon of the wet paramo soils. MTT of the streams is relatively short (0.15–0.73 years, 53–264 days). Regression analysis revealed a negative correlation between the catchment's average slope and MTT (R2 = 0.78, p