The Weierbach experimental catchment (0.45 km2) is the most instrumented and studied sub-catchment in the Alzette River basin in Luxembourg. Within the last decade, it has matured towards an interdisciplinary critical zone observatory focusing on a better understanding of hydrological and hydro-geochemical processes. Since 2009, the Weierbach has been extensively equipped for continuously monitoring water fluxes and physico-chemical parameters within different compartments of the critical zone. Additionally, these compartments are sampled fortnightly at several locations to analyze d18O and d2H isotopic composition of water including rainfall, throughfall, soil water, groundwater and streamwater. This link provide the entire database acquired from 2009 to 2019 for hydro-climatological parameters and water isotopic composition. This repository contains a summary table containing site and monitoring meta data (Weierbach_site-description_2009-2019.xls). Hydro-climatological data: Rainfall (2009-2019, 10- and 15-min interval, 1 site). Throughfall (2012-2019, fortnightly, 3 sites). Air temperature and air humidity (2012-2019, 15-min interval, 2 sites) Water discharge (2009-2019, 15-min interval, 4 sites). Groundwater depths (2009-2019, 15-min interval, 5 sites) Soil water content at 10, 20, 40 and 60 cm depths (2012-2019, 30-min interval, 7 sites). Soil temperature at 10, 20, 40 and 60 cm depths (2012-2019, 30-min interval, 7 sites). d18O and d2H isotopic composition of water: Rain water (2009-2019, accumulated fortnightly). Throughfall (2009-2019, accumulated fortnightly). Stream water (2009-2019, fortnightly). Groundwater (2009-2019, fortnightly). Soil solutions at 20, 40, 60 and 100 cm depth (2009-2014, accumulated fortnightly). Riparian water at 10 cm depth (2010-2019, accumulated fortnightly). Tritium measurements in water: Stream water (2011-2017, sporadically).

The authors acknowledge funding from the Luxembourg National Research Fund (FNR) for sampling and analysis through the projects: BIGSTREAM (CORE/C09/SR/14), SOWAT (CORE/C10/SR/799842), ECSTREAM (CORE/C12/SR/40/8854), CAOS (INTER/DFG/11/01), CAOS2 (INTER/DFG/14/02), AFR Cristina Moragues (AFR/9188481), STORE‐AGE project (CORE/C14/SR/8353440), HYDRO-CSI (PRIDE15/10623093), PATHFINDER (AFR/10189601) and EFFECT (CORE/C17/SR/11702136).