Temporal and spatial fluctuations of groundwater-derived alkalinity fluxes to a semiarid coastal embayment.

摘要: We conducted a comprehensive analysis of variety geochemical data including total alkalinity (TA), dissolved inorganic carbon (DIC), organic (DOC), major ions, stable isotopes, and submarine groundwater discharge, to understand biogeochemical hydrologic processes driving the seasonal annual estuarine buffering capacity in Nueces Bay, Texas. These measurements, together with statistical modeling, show large variability freshwater influence. TA consumption, common spring seasons, was mainly driven by CaCO3 precipitation and, some extent, aerobic respiration. production occurred parts bay during summer, fall winter, likely denitrification. dissolution is stimulated input undersaturated river waters following significant flooding events. Since consumption not necessarily associated different salinity zones, SGD, identified be year-round, offsets effects changes. Net DIC fluxes exceeded flux an order magnitude, except for winter 2014 when it same magnitude. In addition generally larger SGD rates compared other studies, (DIC DOC) bottom sediments, as observed this study, leads fluxes, especially driest season (winter 2014), mid-bay area (6.27·106μMm-2d-1). Consistently inputs occur along shoreline stations (6.14·106μMm-2d-1) flood recession, (1.26·106μMm-2d-1) are lower summer 2015 flooding. This study demonstrates that carbonate chemistry estuaries semiarid areas affected non-conservative because hydroclimatic conditions.