Geostatistical modelling on stream networks: developing valid covariance matrices based on hydrologic distance and stream flow
Geostatistical modelling on stream networks: developing valid covariance matrices based on hydrologic distance and stream flow
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DOI：
10.1111/j.1365-2427.2006.01686.x
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发表时间：
2007-02-01
影响因子：
2.7
通讯作者：
Hoef, Jay M. Ver
中科院分区：
文献类型：
--
作者：
Peterson, Erin E.;Theobald, David M.;Hoef, Jay M. Ver
1.基于欧氏距离的地统计学模型不能代表河流网络中站点的空间配置、连通性和方向性，并且对于许多淡水河流的化学、物理和生物研究可能不具有生态相关性。功能距离测量，例如对称和不对称水文距离，更准确地代表生物、物质和能量通过溪流网络的转移。然而，计算一个大的研究区域的水文距离仍然具有挑战性，用水文距离代替欧几里得距离可能违反地质统计建模的规定。我们提供了一个审查的地质统计建模假设，并讨论了统计和生态后果的替代水文距离措施的欧氏距离。我们还描述了一个新的家庭的自协方差模型，我们开发的河流网络，这是基于水文距离测量。我们描述了地理信息系统（GIS）的方法，用于生成空间数据的地质统计建模在流网络。我们还提供了一个例子，说明了用于创建一个有效的协方差矩阵的方法，该矩阵基于非对称水文距离，并按流量加权，可纳入常见的地质统计模型。所描述的方法和工具提供了具有生态意义和统计有效的河流网络地质统计模型。它们还为河流生态学家提供了开发自己的距离和连通性功能措施的机会，这将改善未来为河流网络开发的地质统计模型。提供这里介绍的地理信息系统工具是为了便利在淡水生态学中应用有效的地质统计模型。
1. Geostatistical models based on Euclidean distance fail to represent the spatial configuration, connectivity, and directionality of sites in a stream network and may not be ecologically relevant for many chemical, physical and biological studies of freshwater streams. Functional distance measures, such as symmetric and asymmetric hydrologic distance, more accurately represent the transfer of organisms, material and energy through stream networks. However, calculating the hydrologic distances for a large study area remains challenging and substituting hydrologic distance for Euclidean distance may violate geostatistical modelling assumptions.2. We provide a review of geostatistical modelling assumptions and discuss the statistical and ecological consequences of substituting hydrologic distance measures for Euclidean distance. We also describe a new family of autocovariance models that we developed for stream networks, which are based on hydrologic distance measures.3. We describe the geographical information system (GIS) methodology used to generate spatial data necessary for geostatistical modelling in stream networks. We also provide an example that illustrates the methodology used to create a valid covariance matrix based on asymmetric hydrologic distance and weighted by discharge volume, which can be incorporated into common geostatistical models.4. The methodology and tools described supply ecologically meaningful and statistically valid geostatistical models for stream networks. They also provide stream ecologists with the opportunity to develop their own functional measures of distance and connectivity, which will improve geostatistical models developed for stream networks in the future.5. The GIS tools presented here are being made available in order to facilitate the application of valid geostatistical modelling in freshwater ecology.