Longitudinal river ecohydrology: flow variation down the lengths of alluvial rivers
Longitudinal river ecohydrology: flow variation down the lengths of alluvial rivers
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纵向河流生态水文学：沿冲积河长度的流量变化
DOI：
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发表时间：
2011
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通讯作者：
J. Diettrich
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作者：
S. Larned;J. Schmidt;T. Datry;C. Konrad;Jennifer K. Dumas;J. Diettrich
径流纵向变化是河流生态水文学的一个新兴研究领域。洪水、低流量和不稳定性的频率、强度、持续时间和时间的纵向变化为依赖流量的物种和生态过程创造了一个动态环境。纵向流量变化和流量-生态系统关系的分析需要沿着河流多个站点的天气流量时间序列。复杂的河道地貌和配备多个流量计的河流稀缺，减缓了纵向生态水文学的进展。经验纵向流模型（ELFMOD）是一种新的统计工具，用于估计沿着河流的多个点的流量，它避免了对多个仪表的要求。在这项研究中，我们使用ELFMOD探索纵向流量变化在四个冲积河流从不同的地质地形和气候区：阿尔巴林（法国），梅托（美国）和塞尔温和奥拉里（新西兰）。不同河流的径流量在时间×地点流量矩阵和纵剖面上的变化存在明显差异。不同的纵向梯度在流量大小、流量分布、重现性、范围和干缩率等方面存在显著差异。纵向流动持久性模式也存在很大差异。干通道的长度和数量的干河段的时间变化主要是季节性的Albarine和Methow，和年际的Orari和Selwyn。河流纵向流型的广泛差异对应于水文地貌不连续性的配置差异，如支流汇流，通道分歧和收敛，岩性接触。版权所有© 2010约翰威利父子有限公司.
Longitudinal flow variation is an emerging field of study in river ecohydrology. Longitudinal changes in the frequencies, magnitudes, durations and timing of floods, low‐flows and intermittence create a dynamic environment for flow‐dependent species and ecological processes. Analyses of flow variation and flow–ecosystem relationships in the longitudinal dimension require synoptic flow time‐series at multiple sites along a river. Complex channel geomorphology and a scarcity of rivers equipped with multiple flow gauges have slowed progress in longitudinal ecohydrology. The empirical longitudinal flow model (ELFMOD) is a new statistical tool for estimating flows at multiple points along rivers; which circumvents the requirement for multiple gauges. In this study, we used ELFMOD to explore longitudinal flow variation in four alluvial rivers from different geological terrains and climate zones: the Albarine (France), Methow (USA) and Selwyn and Orari (New Zealand). Differences among rivers in longitudinal and temporal flow variation were evident on date × location flow matrices and longitudinal profiles. There were notable differences among longitudinal gradients in flow magnitude and flow percentiles, and in the recurrence, extent, and rate of expansion and contraction of dry river reaches. There were also large differences in longitudinal flow‐permanence patterns. Temporal variation in the lengths of dry channel and numbers of dry reaches was predominately seasonal in the Albarine and Methow, and interannual in the Orari and Selwyn. Broad differences among the rivers in longitudinal flow patterns correspond to differences in the configuration of hydrogeomorphic discontinuities such as tributary confluences, channel divergences and convergences, and lithological contacts. Copyright © 2010 John Wiley & Sons, Ltd.