1. Screenshot from excel spreadsheet.

  1. Clustered column graph for percentage composition by particle size class.

  1. The predominant particle size at site 2 representing the downstream part is size 16mm to 32mm while the predominant particle size at site 3 representing the upstream part is in the category of less than 2mm. The average turbidity at site 2 is 7.12. This implies that water is clearer downstream than it is upstream.

  2. Line graph representing cumulative percentage composition by size class for samples upstream at site 3 and samples downstream at site 2.

Size class (mm)

Cumulative percentage

  1. The median size class of particles lies between 16 and 32. It is clear that the fine and small particles will be found upstream as opposed to larger particles which will be found downstream. All particles that are between 8 and 16mm or less will be found upstream.

  2. Average discharge = 93cfs

TSSfor RCR = 11.9mg/L

1cf= 28.3L hence 93cfs will be equivalent to (93 x 28.3) L.

Thereare (11.9 x 28.3) mg in 1cf = 336.77mg/cf.

Adischarge of 93cfs will give a flow of (93 x 336.77) mg/s = 31319.61mg/s. This will give the amount of solids flowing down the RCR persecond.


  1. Based on the observations that have been made previously, we can hypothesize that turbidity of the Red Cedar River reduces as you move from upstream to downstream. The null hypothesis in this case will be that there is no difference in turbidity on the Red Cedar River upstream or downstream.

  2. To test the feasibility of this hypothesis, we can take direct measurements of turbidity at specific intervals of the river and to qualify the readings, we can count the particles as in Lab 5. This will be done on assumption that the soil characteristics are the same along the given stretch of the river. Particles flowing in the river can also be ascertained at the same intervals as above. Other than direct measurements of turbidity, we can verify by graph as shown below that a relationship exists between the sizes of particles found downstream and the size of those found upstream.

  3. Such a relationship can be established when we plot the counts obtained at sites upstream (Y axis) against counts of particle sizes obtained downstream (X axis) and drawing a line that best fits the points so plotted. The units on each axis will be a number that represents a count on a particular class size downstream against the same class size count but on the lower part of the stream (downstream).

Inthis case, the graph shows that the size of a particle obtained canbe determined by the position of the river flow and that arelationship can be established between the size and position on theriver. The more you go downstream, the more you encounter largerparticle sizes. The finer particles give a higher turbidity and thelarger particles give a lower turbidity.

Theworld health organization in an article on fact sheet 2.33 indicatesthat good water should have a turbidity of at most 5NTUs whilechlorinated water should get to at most 1NTU [ CITATION WHO14 l 1033 ]. Other factors remaining constant our lab work therefore should beable to indicate lower turbidity in the rivers water downstream.


WHO. (n.d.). who.int. Retrieved October 8, 2014, from World Health Organization website: http://www.who.int/water_sanitation_health/hygiene/emergencies/fs2-33pdf