Sediment load in rivers 1

[JohnWeal]

Good Afternoon,

Is there any data available that gives typical concentrations of silt and sand at various levels of flow in rivers?

I appreciate that this a very complex field data gathering exercise over a long period and also at different types of the year weather conditions etc etc.

I would have to make a judgement on various information I gather on the internet if there is nothing published and allow for worst cases and any mitigating circumstances deemed appropriate.

Our river is some 50 km downstream from the mountains and is located in Northern Iraq (The Greater Zab River) which flows eventually in to the Tigris.

Be grateful for any help.

Best Regards
John

 

[beej67]

It is a very complicated question, and depends on the the sediment characteristics, topography, and the basin hydrology. The basin hydrology itself varies by land cover, climate, and such.

The best overall treatment I've seen for the question was in Chapter 10 of this textbook:

https://www.amazon.com/Open-Channel-Hydraulics-Terry-Sturm/dp/0073397873

..although fair warning the treatment is very technical. The short answer is that sediment load is most affected by stream power, and that changes in basin hydrology which increase stream power cause an increase in sediment load until the channel achieves a new stability at its new load rate over the course of decades or longer. Until the new stability is achieved, the bed and banks of the stream experience increased erosion to meet the sediment load requirements of the increased stream power.



Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[bimr]

The best resource will be a water treatment plant in proximity to your project. Anything else is a WAG.

 

[cvg]

we work with engineers (PhD types) that specialize in sediment transport analysis. this is not something you will find posted on the internet. if you want any chance of coming up with a reasonable estimate, you will need an expert to obtain data and do an analysis. it does not take years of field data gathering but you will need soil samples / survey and hydrology as well as good topographic data.

An estimate of watershed erosion could be made using the Modified Universal Soil Loss Equation (MUSLE).