Understanding how changing environmental conditions influence phytoplankton growth in the Elbe River Basin using the coupled PhytoBasinRisk and MONERIS models

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A90238%2F24%3AN0000002" target="_blank" >RIV/60076658:90238/24:N0000002 - isvavai.cz</a>

Result on the web

—

DOI - Digital Object Identifier

—

Result language

angličtina

Original language name

Understanding how changing environmental conditions influence phytoplankton growth in the Elbe River Basin using the coupled PhytoBasinRisk and MONERIS models

Original language description

Phytoplankton is a key indicator of ecosystem health in surface waters, which are among the most degraded ecosystems globally. Despite extensive research into the factors influencing phytoplankton growth, not enough is known about how changing environmental conditions will affect phytoplankton in the future, especially with the mounting pressures of anthropogenic climate change. Using chlorophyll-a as a proxy for phytoplankton biomass, the coupled PhytoBasinRisk and MONERIS models, incorporating several new developments, were employed in this thesis to model monthly chlorophyll-a concentrations in the Elbe River Basin during the period 2005- 2020. Satisfactory model accuracy metrics were achieved (monthly: R2: 0.45, NSE: 0.39, PBIAS: 9.05%; seasonally: R2: 0.65, NSE: 0.63, PBIAS: 5.07%), effectively reproducing temporal and spatial patterns of chlorophyll-a concentrations along the main river course. The assessment of individual environmental factor significance showed general agreement with literature, especially regarding water residence time and morphological subcatchment characteristics as the main factors controlling the spatial variability of chlorophyll-a concentrations. New insights emerged regarding silica, which may be more significant in diatom-rich rivers like the Elbe than previously thought, and discharge, which shows a less pronounced negative correlation with chlorophyll-a than expected. Testing the model’s sensitivity to changing environmental conditions under contrasting hydrological conditions revealed that hydrologically dry conditions associated with climate change will likely lead to changes in chlorophyll-a concentrations of greater magnitude and with greater spatial and temporal variability. To assess this finding with greater certainty, better capture diverse environmental conditions, and enhance the suitability of PhytoBasinRisk for future scenario simulations, several limitations affecting result consistency and reliability need to be addressed. In light of these limitations, the two primary recommendations for future work are to dynamically model nutrient uptake as part of phytoplankton growth and to enhance the estimation of water residence time.

Czech name

—

Czech description

—

Type

O - Miscellaneous

CEP classification

—

OECD FORD branch

10700 - Other natural sciences

Project

—

Continuities

—

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů