Fig. 2: Factors and processes leading to low and high groundwater DOC concentrations.
From: Changes in global groundwater organic carbon driven by climate change and urbanization
a Conditions leading to low groundwater DOC concentrations. b Conditions leading to high groundwater DOC concentrations. Factors negatively correlated with groundwater DOC concentrations include increasing pH, DO, Na and Si, precipitation in the wettest and driest months, temperature in the warmest quarter, sample depth, elevation and aquifer age. Factors positively correlated with groundwater DOC concentrations include Mn, Ca, Fe, and K, groundwater temperature and temperatures in the wettest quarter. Urban land use was found to be 18% and 19% higher in groundwater DOC concentrations than agricultural and natural land uses, respectively.
