QA/QC-ed Groundwater Level Time Series in PLM-1 and PLM-6 Monitoring Wells, East River, Colorado (2016-2022)

This data set contains QA/QC-ed (Quality Assurance and Quality Control) water level data for the PLM1 and PLM6 wells. PLM1 and PLM6 are location identifiers used by the Watershed Function SFA project for two groundwater monitoring wells along an elevation gradient located along the lower montane life zone of a hillslope near the Pumphouse location at the East River Watershed, Colorado, USA. These wells are used to monitor subsurface water and carbon inventories and fluxes, and to determine the seasonally dependent flow of groundwater under the PLM hillslope. The downslope flow of groundwater in combination with data on groundwater chemistry (see related references) can be used to estimate rates of solute export from the hillslope to the floodplain and river. QA/QC analysis of measured groundwater levels in monitoring wells PLM-1 and PLM-6 included identification and flagging of duplicated values of timestamps, gap filling of missing timestamps and water levels, removal of abnormal/bad and outliers of measured water levels. The QA/QC analysis also tested the application of different QA/QC methods and the development of regular (5-minute, 1-hour, and 1-day) time series datasets, which can serve as a benchmark for testing other QA/QC techniques, and will be applicable for ecohydrological modeling. The package includes a Readme file, one R code file used to perform QA/QC, a series of 8 data csv files (six QA/QC-ed regular time series datasets of varying intervals (5-min, 1-hr, 1-day) and two files with QA/QC flagging of original data), and three files for the reporting format adoption of this dataset (InstallationMethods, file level metadata (flmd), and data dictionary (dd) files).QA/QC-ed data herein were derived from the original/raw data publication available at Williams et al., 2020 (DOI: 10.15485/1818367). For more information about running R code file (10.15485_1866836_QAQC_PLM1_PLM6.R) to reproduce QA/QC output files, see README (QAQC_PLM_readme.docx). This dataset replaces the previously published raw data time series, and is the final groundwater data product for the PLM wells in the East River. Complete metadata information on the PLM1 and PLM6 wells are available in a related dataset on ESS-DIVE: Varadharajan C, et al (2022). https://doi.org/10.15485/1660962. These data products are part of the Watershed Function Scientific Focus Area collection effort to further scientific understanding of biogeochemical dynamics from genome to watershed scales. 2022/09/09 Update: Converted data files using ESS-DIVE’s Hydrological Monitoring Reporting Format. With the adoption of this reporting format, the addition of three new files (v1_20220909_flmd.csv, V1_20220909_dd.csv, and InstallationMethods.csv) were added. The file-level metadata file (v1_20220909_flmd.csv) contains information specific to the files contained within the dataset. The data dictionary file (v1_20220909_dd.csv) contains definitions of column headers and other terms across the dataset. The installation methods file (InstallationMethods.csv) contains a description of methods associated with installation and deployment at PLM1 and PLM6 wells. Additionally, eight data files were re-formatted to follow the reporting format guidance (er_plm1_waterlevel_2016-2020.csv, er_plm1_waterlevel_1-hour_2016-2020.csv, er_plm1_waterlevel_daily_2016-2020.csv, QA_PLM1_Flagging.csv, er_plm6_waterlevel_2016-2020.csv, er_plm6_waterlevel_1-hour_2016-2020.csv, er_plm6_waterlevel_daily_2016-2020.csv, QA_PLM6_Flagging.csv). The major changes to the data files include the addition of header_rows above the data containing metadata about the particular well, units, and sensor description. 2023/01/18 Update: Dataset updated to include additional QA/QC-ed water level data up until 2022-10-12 for ER-PLM1 and 2022-10-13 for ER-PLM6. Reporting format specific files (v2_20230118_flmd.csv, v2_20230118_dd.csv, v2_20230118_InstallationMethods.csv) were updated to reflect the additional data. R code file (QAQC_PLM1_PLM6.R) was added to replace the previously uploaded HTML files to enable execution of the associated code. R code file (QAQC_PLM1_PLM6.R) and ReadMe file (QAQC_PLM_readme.docx) were revised to clarify where original data was retrieved from and to remove local file paths.

本数据集包含经过质量保证与质量控制（Quality Assurance and Quality Control，QA/QC）处理的PLM1与PLM6两口监测井的水位数据。PLM1与PLM6是流域功能科学聚焦区（Watershed Function Scientific Focus Area，SFA）项目所用的位置标识符，指代美国科罗拉多州东河流域泵房附近山坡下山地生物带内沿海拔梯度分布的两口地下水监测井。该两口监测井用于监测地下水体与碳库储量及通量，并解析PLM山坡下地下水的季节性流动规律。结合地下水化学数据（详见相关参考文献），可通过山坡下坡向地下水流动过程，估算溶质从山坡向漫滩与河道的输出速率。

对PLM1与PLM6监测井实测地下水位开展的QA/QC分析，涵盖了时间戳重复值的识别与标记、缺失时间戳与水位数据的间隙填补，以及实测水位异常值、无效值与离群值的剔除。本次QA/QC分析还验证了不同QA/QC方法的应用效果，并生成了5分钟、1小时、1天三种固定时间步长的时序数据集，该数据集可作为测试其他QA/QC技术的基准数据集，同时可应用于生态水文建模研究。

本数据集套件包含1个说明文档（Readme文件）、1份用于执行QA/QC分析的R代码文件、8个数据CSV文件（其中6个为不同时间步长的QA/QC处理后固定时序数据集，步长分别为5分钟、1小时与1天，另外2个为原始数据的QA/QC标记文件），以及3个适配本数据集报告格式的文件：安装方法（InstallationMethods）、文件级元数据（file level metadata，flmd）与数据字典（data dictionary，dd）文件。

本数据集所包含的QA/QC处理后数据，源自Williams等人2020年发布的原始/未处理数据（DOI: 10.15485/1818367）。如需了解如何运行R代码文件（10.15485_1866836_QAQC_PLM1_PLM6.R）以复现QA/QC输出文件，请参阅说明文档（QAQC_PLM_readme.docx）。

本数据集替代了此前发布的原始数据时序集，为东河流域PLM监测井的最终地下水数据产品。PLM1与PLM6监测井的完整元数据可在ESS-DIVE平台的关联数据集（Varadharajan C等，2022，DOI: https://doi.org/10.15485/1660962）中获取。本数据产品隶属于流域功能科学聚焦区项目的数据集整合工作，旨在推动从基因组到流域尺度的生物地球化学动力学机制的科学认知。

2022年9月9日更新：采用ESS-DIVE水文监测报告格式转换所有数据文件。适配该报告格式后，新增3个文件：v1_20220909_flmd.csv、V1_20220909_dd.csv与InstallationMethods.csv。文件级元数据文件（v1_20220909_flmd.csv）包含数据集内各文件的专属元信息；数据字典文件（v1_20220909_dd.csv）收录了数据集内所有列标题与相关术语的定义说明；安装方法文件（InstallationMethods.csv）详细说明了PLM1与PLM6监测井的安装与部署方法。此外，8个数据文件已按报告格式规范完成重新格式化，具体包括：er_plm1_waterlevel_2016-2020.csv、er_plm1_waterlevel_1-hour_2016-2020.csv、er_plm1_waterlevel_daily_2016-2020.csv、QA_PLM1_Flagging.csv、er_plm6_waterlevel_2016-2020.csv、er_plm6_waterlevel_1-hour_2016-2020.csv、er_plm6_waterlevel_daily_2016-2020.csv与QA_PLM6_Flagging.csv。数据文件的主要变更内容为：在数据上方新增了包含对应监测井信息、单位及传感器说明的表头行。

2023年1月18日更新：本数据集新增了截至2022年10月12日的ER-PLM1水位数据，以及截至2022年10月13日的ER-PLM6水位数据，所有新增数据均已完成QA/QC处理。适配报告格式的配套文件（v2_20230118_flmd.csv、v2_20230118_dd.csv、v2_20230118_InstallationMethods.csv）已完成更新，以反映新增的数据内容。新增了R代码文件（QAQC_PLM1_PLM6.R）以替代此前上传的HTML文件，实现相关代码的直接运行。对R代码文件（QAQC_PLM1_PLM6.R）与说明文档（QAQC_PLM_readme.docx）进行了修订，明确了原始数据的获取来源，并移除了本地文件路径信息。