EMMALAB v. 1.0

Quantifying water sources to rivers and streams is critical for managing water resources globally. Endmember mixing analysis (EMMA) is a commonly applied method to water sources to streams that uses tracers for hydrograph separation. Most EMMA applications follow similar methods, but several choices must be made such as selecting tracers, endmembers, and stream locations for mixing. With no standardized EMMA approach, these choices may be made subjectively with little regard for resulting errors. We created an open-source software program called EMMALAB, developed in Matlab App Designer, to simplify and standardize the workflow associated with EMMA. EMMALAB guides the user through a uniform process to visualize and select endmembers via principal components analysis, calculate the fractional contribution of each endmember, and calculate errors in the mixing analysis. The files in this HydroShare resource include: EMMALAB v1.0 installers for Mac and PC, a data template, and example dataset from the Provo River, and the transcript for a YouTube video that provides instructions for using the software. The Provo River dataset is the example data used in the training video.

量化河流与溪流的水源构成，对全球水资源管理至关重要。端元混合分析（Endmember Mixing Analysis, EMMA）是一种广泛应用于溪流水源解析的方法，通过示踪剂实现水文分割。尽管多数EMMA应用遵循相似的流程框架，但仍存在多项需人工抉择的关键环节，例如示踪剂选取、端元设定以及用于混合分析的溪流采样点位选择等。由于目前尚无统一标准化的EMMA实施规范，此类抉择往往带有较强主观性，且极少考量由此引发的分析误差。为此，我们开发了一款基于Matlab应用设计器（Matlab App Designer）构建的开源软件EMMALAB，旨在简化并标准化EMMA的全流程工作流。EMMALAB可引导用户遵循统一流程，通过主成分分析（Principal Components Analysis, PCA）实现端元的可视化与选取，计算各端元的贡献占比，并输出混合分析过程中的误差结果。本HydroShare资源包含以下文件：适用于Mac与PC平台的EMMALAB v1.0安装程序、数据模板、普罗沃河（Provo River）示例数据集，以及讲解该软件使用方法的YouTube视频字幕文稿。普罗沃河数据集即为该培训视频中所使用的示例数据。