Warming Alters Hydrologic Heterogeneity: Simulated Climate Sensitivity of Hydrology‐Based Microrefugia in the Snow‐to‐Rain Transition Zone
Warming Alters Hydrologic Heterogeneity: Simulated Climate Sensitivity of Hydrology‐Based Microrefugia in the Snow‐to‐Rain Transition Zone
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DOI：
10.1029/2018wr023063
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发表时间：
2019-03
影响因子：
5.4
通讯作者：
A. Marshall;T. Link;J. Abatzoglou;G. Flerchinger;D. Marks;L. Tedrow
中科院分区：
文献类型：
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作者：
A. Marshall;T. Link;J. Abatzoglou;G. Flerchinger;D. Marks;L. Tedrow
在复杂地形条件下，积雪形成了生态水文景观异质性和生态避难所。在这项研究中，我们评估了水文动力学的气候敏感性在半干旱山区集水区的雪-雨过渡带。该集水区包括一个独特的雪堆补贴避难所，包括一小部分（14.5%）的流域，但占不成比例的量（模拟平均56%）的水文通量生成。我们进行了气候敏感性实验，使用物理为基础的水文模型，以评估一套水文指标在整个流域的响应。在3.5 °C的温度下进行的实验表明，平均最大雪水当量减少了58-68%，深层渗透减少了72%。虽然整个流域的相对减少量相似，但漂移补贴站点的积雪绝对减少量要比周围景观大得多。在漂移补贴地区，变暖导致从包括能量和水限制蒸散条件的制度转变为完全水限制条件。气候变暖也导致水文指标的年际变化。漂移补贴单元比周围景观对变暖更敏感，增加降水抵消变暖影响的可能性降低。尽管在气候空间均匀的变化，气候变化对水文动力学的影响是空间异质性的，在这个流域由于存在的横向水分输送的形式，飘雪。这些研究结果表明，整个景观的水文均匀性增加，雪堆补贴避难所的变化相对较大。
In complex terrain, drifting snow contributes to ecohydrologic landscape heterogeneity and ecological refugia. In this study, we assessed the climate sensitivity of hydrological dynamics in a semiarid mountainous catchment in the snow‐to‐rain transition zone. This catchment includes a distinct snow drift‐subsidized refugium that comprises a small portion (14.5%) of the watershed but accounts for a disproportionate amount (modeled average 56%) of hydrological flux generation. We conducted climate sensitivity experiments using a physically based hydrologic model to assess responses of a suite of hydrologic metrics across the watershed. Experiments with an imposed 3.5 °C warming showed reductions in average maximum snow water equivalent of 58–68% and deep percolation by 72%. While relative decreases were similar across the watershed, much greater absolute decreases in snowpack occurred in the drift‐subsidized site than the surrounding landscape. In drift‐subsidized locations, warming caused a shift from a regime that included both energy‐ and water‐limited evapotranspiration conditions to exclusively water‐limited conditions. Warming also resulted in altered interannual variability of hydrologic metrics. The drift‐subsidized unit was more sensitive to warming than the surrounding landscape, with reduced potential for the effects of warming to be offset by increased precipitation. Despite spatially homogeneous changes in climate, the effects of climate change on the hydrological dynamics were spatially heterogeneous in this watershed due to the presence of lateral water transport in the form of drifting snow. These findings suggest an increase in hydrologic homogeneity across the landscape and relatively large changes in snow drift‐subsidized refugia.