Transient evolution of suspended and benthic algae in a riverine ecosystem: A numerical study

Sumit Sinha

Ecological Modelling, 2017, vol. 348, issue C, 78-92

Abstract: It is a well-established fact that there is no direct resource competition between pelagic and benthic primary producers when their habitats are located in physically separate areas. However, the benthic habitat located at the bottom of the water column is affected by the light rays that gets attenuated as it passes through the pelagic zone and is obstructed by the algal cells and suspended material present in the water column. Therefore, benthic primary production is very much influenced by the conditions and concentrations in the pelagic zone. Another level of complexity is added to the system while considering the impact of flowing water in a riverine environment. In the research presented here a numerical model is developed to examine the impact of flow and nutrients on pelagic and benthic primary producers. The aforementioned numerical model solves advection diffusion and reaction (ADR) equation through TVD (total variation diminishing) − MacCormack scheme. The diffusion term is solved through central difference scheme. The model results are first validated by comparing the results with analytical solutions for the simplified case. The validated model is then applied to a 30kms stretch of the Bode River and simulations are conducted for multiple flow conditions. Impact of transient flow and nutrient boundary conditions on the evolution of algal trait is examined. Our simulation exercise highlights the importance of residence time in the temporal evolution of algae in pelagic and benthic zone and further identifies the most sensitive parameter influencing the evolution of the algal community modelled. Our research also reveals that largest uncertainty in the modelling stems from the wide range of entrainment rate that could be used for modelling resuspension of benthic algae in pelagic zone. The use of higher entrainment rate increased the algal concentration in the water column by 48% for identical flow conditions.

Keywords: Pelagic algae; Benthic algae; Eutrophication; Numerical modelling (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0304380016307219
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:ecomod:v:348:y:2017:i:c:p:78-92

DOI: 10.1016/j.ecolmodel.2017.01.008

Access Statistics for this article

Ecological Modelling is currently edited by Brian D. Fath

More articles in Ecological Modelling from Elsevier
Bibliographic data for series maintained by Catherine Liu ().