Sara Sandström

I work as a Postdoc at the Department of Soil and Environment where my focus is phosphorus and modelling of phosphorus transport. I recently (October 2022) defended my thesis at the Department of aquatic sciences and assessment and I belong to the section for geochemistry and hydrology. My main focus is phosphorus (P) attached to suspended material in small agricultural streams. Besides my own project, my special interests lies in working with different Geographical information systems (GIS) and automatisation of GIS-calculations in Python.

I have been teaching hydrology in the course Energisystem ur ett biogeovetenskapligt perspektiv (swedish) during the fall 2018, 2019 and 2020 for civil engineers.

I have also been an administrator and teaching assisstant for the PhD course Multivariate methods for ecologists during fall 2020.

Elevated P-concentrations in surface waters is a known contributor to eutrophication and degraded water quality, where agriculture is a known main P-source. However, the role and composition of fluvial sediment and attached P is less known. Through my thesis we wanted to increase the understanding for these processes with modeling for identification of CSAs for P-transport with distributed high-resolution erosion models as well as field and labwork that looks closer at the suspended material and the different P-fractions attached to it.

The first part of the project concerns field and labwork where suspended material has been collected from small agricultural streams in four different agricultural catchments with time integrated Philippes samplers. All these areas are a part of the Swedish national environmental monitoring program. The samplers were emptied and reinstalled once every 8-10 weeks, and the material was then analyzed with P-fractionation to find the different P-species during fall 2017, 2018 and 2019. The analysis showed e.g. that iron bound P in fluvial suspended sediment varied over season with high concentrations during summer time and low concentrations during winter time. Read the full article in Journal of the Environmental Quality: https://acsess.onlinelibrary.wiley.com/doi/full/10.1002/jeq2.20210 

The second part of the project is based on historical time-series data from these small agricultural catchments that are a part of the Swedish environmental monitoring programme. We mainly studied at the connection between particluate P and the concentration of suspended material and how this can be linked to the catchment's properties, e.g. soil type. Connections between clay content, percentage agricultural land and suspended solids were established, as well as between suspended solids and particulate phosphorus. See more of the results in the following article in Science of the Total Environment: https://www.sciencedirect.com/science/article/pii/S0048969719346078

The last parts of the project was focused on modelling where we further developed a distributed high-resolution erosion model to identify CSAs for particle and P-transport and how they change over time. This is now published in Frontiers of Environmental Science. We also used environmental monitoring data to scale up previous found relationships between catchments characteristics and phosphorus and suspended solids to larger catchments with good agreement. All this is summarised in my thesis that was defended on the 6th of October, 2022.

Master programme in Environmental and Water Engineering, Uppsala University (2012-2017).

PhD in environmental analysis, SLU (2017-2022).

Main supervisor: Faruk Djodjic, Department of Aquatic Sciences and Assessment, SLU.

Martyn Futter, Department of Aquatic Sciences and Assessment, SLU.

Kevin Bishop, Department of Aquatic Sciences and Assessment, SLU.

Katarina Kyllmar, Department of Soil and Environment, SLU.

Sara Sandström, Martyn N. Futter, Katarina Kyllmar, Kevin Bishop, David W. O'Connell, Faruk Djodjic,
Particulate phosphorus and suspended solids losses from small agricultural catchments: Links to stream and catchment characteristics,
Science of The Total Environment,
2019,
134616,
ISSN 0048-9697,
https://doi.org/10.1016/j.scitotenv.2019.134616.

https://www.sciencedirect.com/science/article/pii/S0048969719346078

Emma E. Lannergård, Oskar Agstam-Norlin, Brian J. Huser, Sara Sandström, Jelena Rakovic, & Martyn N. Futter.

New Insights into Legacy Phosphorus from Fractionation of Streambed Sediment. Journal of Geophysical Research: Biogeosciences,

2020,

https://doi.org/10.1029/2020JG005763

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020JG005763

 
Sara Sandström, Martyn N. Futter, David W. O'Connell, Emma E. Lannergård, Jelena Rakovic, Katarina Kyllmar, Laurence W. Gill & Faruk Djodjic

Variability in fluvial suspended and streambed sediment phosphorus fractions among small agricultural streams. Journal of Environmental Quality, 

2021,

https://doi.org/10.1002/jeq2.20210

https://acsess.onlinelibrary.wiley.com/doi/full/10.1002/jeq2.20210

Thesis: Sources, composition and transport of fluvial suspended sediment and attached phosphorus in agricultural catchments: A cross-scale analysis

https://publications.slu.se/?file=publ/show&id=118804

Sara Sandström, Hampus Markensten, Martyn N. Futter, Katarina Kyllmar, David W. O'Connell, Kevin Bishop & Faruk Djodjic

Distributed dynamic modelling of suspended sediment mobilization and transport from small agricultural catchments. Frontiers in Environmental Science,

2023

https://www.frontiersin.org/articles/10.3389/fenvs.2023.1196048/full