A simple biogeochemical model for estuaries with high sediment loads: Application to the Guadalquivir River (SW Iberia)

Estuaries are transition ecosystems connecting land and sea and are subjected to a number of external forcings with a broad range of variation frequencies, from daily to seasonal and climate scales. Estuaries strongly influence the biogeochemical and hydrodynamic conditions of nearby coastal sites and are also considered to be particularly sensitive to anthropogenic activity and to climate-driven changes. All these together make it especially desirable to develop numerical models of estuarine systems that are able to resolve their different spatial and temporal scales of variability. In the present work, we propose a biogeochemical model for the water column of temperate estuaries based on previously published, well-known models of marine pelagic ecosystems incorporating new state variables (such as organic dissolved material) and biogeochemical constituents (such as oxygen and suspended solids) crucial for these systems. We apply this model to the most important estuary in southern Iberia, the Guadalquivir estuary, and we compare the model results with field data from an extensive three-year monitoring program. We demonstrate that light availability (constrained by suspended material in the water column) severely limits the biological productivity of the estuary, determining the hypoxic conditions of this system. The proposed model is useful for the study of any other estuary with similar biogeochemical characteristics and can be used to assess expected changes in the environmental status of such systems by anthropogenic activity or by climate changes.

RUIZ Javier;  MACIAS MOY Diego;  LOSADA Miguel;  DIEZ-MINGUITO Manuel;  PRIETO Laura; 

2013-08-13

ELSEVIER SCIENCE BV

JRC82132

0304-3800,   

http://www.sciencedirect.com/science/article/pii/S0304380013002962,    https://publications.jrc.ec.europa.eu/repository/handle/JRC82132,   

10.1016/j.ecolmodel.2013.06.01,