Hydrologic similarity among catchments under variable flow conditions
Hydrologic similarity among catchments under variable flow conditions
复制标题
可变流量条件下流域水文相似性
DOI：
10.5194/hess-15-989-2011
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发表时间：
2010
影响因子：
6.3
通讯作者：
M. Stieglitz
中科院分区：
文献类型：
--
作者：
S. Patil;M. Stieglitz
抽象的。为了在无资料集水区进行准确的预测，往往需要对集水区水流响应的区域相似性进行评估。然而，目前尚不清楚是否在所有流量条件下保持集水区之间的相似性。我们解决这个问题，通过分析位于美国东北部的四个流域的25个集水区的流量历时曲线。径流曲线的变异系数被用作跨水流条件的集水区之间变异性的量度。结果表明，流域河流响应的相似性是动态的，并高度依赖于水流条件。具体而言，在四个流域中的每一个流域内，在低流量时，变异系数较高，而在较高流量时，变异系数逐渐降低。对径流年内变化的分析表明，从低流量到高流量年内变化也有类似的减少。在冬季和春季（湿）季节相比，夏季和秋季（干）季节的径流量更大的相似性。结果表明，在低流量的径流空间变异主要是由高蒸发需求的主导地位，在温暖的时期。另一方面，在高流量在寒冷时期的空间变异性控制的降水输入的蒸散量增加的主导地位。通过评估整个径流百分位数范围内的变异性，这项工作从季节的角度探索了水文相似性的本质。
Abstract. An assessment of regional similarity in catchment stream response is often needed for accurate predictions in ungauged catchments. However, it is not clear whether similarity among catchments is preserved at all flow conditions. We address this question through the analysis of flow duration curves for 25 gauged catchments located across four river basins in the northeast United States. The coefficient of variation of streamflow percentiles is used as a measure of variability among catchments across flow conditions. Results show that similarity in catchment stream response is dynamic and highly dependent on flow conditions. Specifically, within each of the four basins, the coefficient of variation is high at low flow percentiles and gradually reduces for higher flow percentiles. Analysis of the inter-annual variation in streamflow percentiles shows a similar reduction in variability from low flow to high flow percentiles. Greater similarity in streamflows is observed during the winter and spring (wet) seasons compared to the summer and fall (dry) seasons. Results suggest that the spatial variability in streamflow at low flows is primarily controlled by the dominance of high evaporative demand during the warm period. On the other hand, spatial variability at high flows during the cold period is controlled by the increased dominance of precipitation input over evapotranspiration. By evaluating variability over the entire range of streamflow percentiles, this work explores the nature of hydrologic similarity from a seasonal perspective.