Local determinants profoundly contribute to the spatiotemporal variation of stream water quality. Natural determinants related to geology, atmospheric deposition associated with precipitation, weathering process, and anthropogenic inputs related to urban, industrial, and agricultural activities also drive spatiotemporal variations in-stream water quality. For more details refer to:

https://link.springer.com/content/pdf/10.1007/s13201-019-1043-4.pdf

Dear Ankur

Thank you very much. Although this article does not answer my question directly, it lists a large number of water parameters. This helps me target them using more precise keywords.

Difficult to determine what might be uniquely the source of water quality from specific catchment or stream. I was thinking of silica, it comes from primarily geologic materials. But then let’s say a plant takes up silica in some neighboring area, and a bird eats some of the plant, flies over our catchment or stream and deposits some of it. Or groundwater from some sources outside of our catchment, and contributes to the flow in the stream. And rainfall picks up dust and silica from distant sources and contributes some into the catchment. As suggested, there are many potential abiotic and biotic sources and forces including anthropogenic activity that can contribute to water quality.

Dear William

Thank you for your answer. It is true that there are uncertainties when it comes to identifying a parameter's source. As my research for answers is going, I think that what is applicable to Suspended sediments is only applicable to its components (Silt, clay, sands...etc.).

It is worth noting that I found some works that study Nitrates and Total phosphorous where they identify their sources but I am yet to see if it is the same behavior as suspended sediments.

Sounds a bit old school, but before the days of super-dooper all knowing simulation models,..... there was a science called empirical science. Can I suggest you look at the work done at Wallingford UK. Initially it was the Flood Studies they focused on.. but later ( and indeed I as a young PhD student did independent work on this) low flows. Both use catchment characteristics (for UK temperate climate) that are map, geological and long-term climate data. I think you might find, their simple empirical regression equations gave better results than todays' models. Only a suggestion that not everything is best when it comes in a pretty graphic from an expensive model consultancy.

ps this was 1970's statistical hydrology.. I am sure 100's if not more equations have been created around the world... so check it out with "Google" or your local water resource research group.

Dear Charles,

Thank you for your answer. As interesting as modelling is, I am still on an earlier phase. I am still trying to learn the processes and dynamics a solute - contaminant - or any matter carried by water behaves. More precisely, I am looking for any parameter, similarly to suspended sediments, that originates from both the stream network as well as the catchment system. I would like to understand the transport dynamics and then see if I can apply an existing model or develop an unmixing model to separate the contributions of the different sources.

The following papers can be of help.

Article Water quality and sediment contamination assessment of Pazar...

Article Landscape Influences On Water Chemistry In Midwestern Stream...

Dear Sujatha Ramani,

Thank you for your answer. I will read and see what I can learn from them.