Comprehensive network hydraulic scaling datasets and associated resources (discharge, channel length surveys, watershed metadata, blueline network shapefiles and reference images)

Wetted channel networks expand and contract throughout the year. Direct observation of this process can be made by multiple intensive surveys of a catchment throughout the year. Godsey et al. (2014) suggest that the extent of the wetted channel network scales with discharge at the outlet by a power law (L = αQ^β). Using this relationship, we developed a framework to assess variability in the extent of wetted channels as a function of β and the variability in streamflow Q (Lapides et al., In Review, https://eartharxiv.org/mc6np/). This resource constitutes the empirical basis for that study, a comprehensive dataset compiled from literature including:

1 - Channel length survey data (csv files)
2 - Discharge time series data (csv files)
3 - Watershed metadata (csv files)
4 - Blueline network files (pdf, png, and shp files)

This collection is comprehensive in that it includes all watersheds where at least three channel length surveys have been conducted and where a corresponding discharge time series dataset is available. The requirement of a minimum of three channel length surveys stems from the data requirements to find α and β for the power law relationship between discharge and stream network length for headwater catchments (Godsey et al., 2014). At present, data for 14 watersheds worldwide are included in the collection along with reference maps, watershed metadata, shapefiles and a composite of USGS blueline stream network imagery with terrain for watersheds of interest in the United States. Notably, this collection brings data from a variety of earth science agencies worldwide into a common, clearly labelled format.

Methods used to process the datasets or create other assets in this collection are included in the abstracts or additional metadata for each of the four resources listed above. Python code used to process data, compute variables, and create graphics is available at: https://zenodo.org/record/4057320

湿润河道网络（wetted channel network）全年处于扩张与收缩的动态变化之中。通过对流域（catchment）开展全年多频次密集实地勘测，可直接观测这一动态过程。Godsey等人（2014年）提出，湿润河道网络的覆盖范围与出口断面流量呈幂律（power law）关系：$L = alpha Q^eta$。基于这一关系，我们构建了一套分析框架，用于评估湿润河道覆盖范围的变异性，该变异性以$eta$值与径流（streamflow）$Q$的变异性为函数（Lapides等人，已投稿待刊，https://eartharxiv.org/mc6np/）。本数据集为该项研究提供了实证基础，是一套从公开文献中整合得到的综合数据集，具体包含：
1. 河道长度勘测数据（CSV格式文件）
2. 径流时间序列数据（CSV格式文件）
3. 流域元数据（watershed metadata）（CSV格式文件）
4. 蓝线水系网络（Blueline network）文件（包含PDF、PNG及SHP格式文件）

本数据集具备全面性，其收录的流域需满足两个条件：至少开展过3次河道长度勘测，且拥有对应的径流时间序列数据集。设置至少3次河道长度勘测的要求，源于求解水源流域（headwater catchments）径流与河道网络长度之间幂律关系参数$alpha$和$eta$的数据需求（Godsey等人，2014年）。目前，本数据集已收录全球范围内14个流域的相关数据，其中包含参考地图、流域元数据、SHP格式文件，以及针对美国目标流域的美国地质调查局（USGS）蓝线水系网络影像与地形的合成图件。值得注意的是，本数据集将全球多家地球科学机构的原始数据整合为统一且标注清晰的格式。

本数据集的处理方法，以及本集合中其他成果的制作方法，均已在上述四类资源的摘要或补充元数据中予以说明。用于数据处理、变量计算及绘图的Python代码可通过以下链接获取：https://zenodo.org/record/4057320