QUADICA - water quality, discharge and catchment attributes for large-sample studies in Germany

This data set provides data of water quality, discharge, driving forces (meteorological and nitrogen surplus), and catchment attributes for a set of 1386 German catchments covering a wide range of natural and anthropogenic conditions. A corresponding paper "Water quality, discharge and catchment attributes for large-sample studies in Germany - QUADICA" by Ebeling et al. describing the data set in detail will be made available in the Journal Earth System Science Data (https://www.earth-system-science-data.net/).

This repository includes:

1.) Water quality data as annual medians of observed concentration data of N, P and C species (c_annual.csv)
2.) Water quantity data as annual medians of observed discharge (q_annual.csv)
3.) Monthly medians over the whole time series of water quality variables and discharge (c_months.csv)
4.) Monthly and annual median concentrations, flow-normalized concentrations, and mean fluxes estimated using Weighted Regressions on Time, Discharge, and Season (WRTDS) for stations with enough data availability (for details see the corresponding paper Ebeling et al.; wrtds_monthly.csv, wrtds_annual.csv).
5.) Meteorological data as monthly median average temperatures and sums of precipitation and potential evapotranspiration (tavg_monthly.csv, pre_monthly.csv, pet_monthly.csv)
6.) N surplus time series on annual basis (n_surplus.csv)
7.) Summary statistics for the stations including number of samples, covered time periods, degree of censoring (concentrations below the detection limit), availability of discharge data, and availability and performance of WRTDS models (metadata.csv).
8.) Description of data tables (Metadata_QUADICA.pdf).

Data on catchment attributes and geodata also part of the QUADICA data set are available at "CCDB - catchment characteristics data base Germany" (https://doi.org/10.4211/hs.82f8094dd61e449a826afdef820a2c19). The metadata of the water quality and quantity data base is available at "WQQDB - water quality and quantity data base Germany" (https://doi.org/10.4211/hs.a42addcbd59a466a9aa56472dfef8721).

Conditions: The data set is freely and easily accessible. Please refer to the corresponding paper Ebeling et al. when using or referring to this data set.

本数据集提供了涵盖德国1386个流域，在广泛自然和人为条件下的水质、排放、驱动因素（气象和氮过剩）以及流域属性的数据。一篇详细描述该数据集的相应论文《德国大样本研究的水质、排放和流域属性——QUADICA》由Ebeling等人撰写，并将发表在《地球系统科学数据》期刊（https://www.earth-system-science-data.net/）。本仓库包含以下内容：

1. 水质数据，以N、P和C物种的年观测浓度数据的平均值（c_annual.csv）
2. 水量数据，以年观测排放的年平均值（q_annual.csv）
3. 水质变量和排放的整个时间序列的月平均值（c_months.csv）
4. 对于数据充足的站点，使用加权回归时间、排放和季节（WRTDS）方法估算的月和年浓度、流量归一化浓度和平均通量（wrtds_monthly.csv, wrtds_annual.csv）
5. 气象数据，以月平均温度和降水及潜在蒸散量的总和（tavg_monthly.csv, pre_monthly.csv, pet_monthly.csv）
6. 年度氮过剩时间序列（n_surplus.csv）
7. 站点汇总统计，包括样本数量、覆盖时间长度、 censoring程度（浓度低于检测限）、排放数据可用性、WRTDS模型可用性和性能（metadata.csv）
8. 数据表描述（Metadata_QUADICA.pdf）。

流域属性和地理数据作为QUADICA数据集的一部分，可在“CCDB - 德国流域特性数据库”（https://doi.org/10.4211/hs.82f8094dd61e449a826afdef820a2c19）获取。水质和水量数据库的元数据可在“WQQDB - 德国水质和水量数据库”（https://doi.org/10.4211/hs.a42addcbd59a466a9aa56472dfef8721）获取。

使用条件：本数据集免费且易于访问。在使用或引用本数据集时，请参阅Ebeling等人的相应论文。