KBS GK-12 Project Data Nugget: Float Down the River Part 1 Name______
Leila Desotelle Pg. 1 Date______
Level 2, Student Copy
Float Down the River
Part 1: Total Suspended Solids
Data provided by and written by GK-12 Fellow Leila Desotelle
Background Information:
Rivers usually have lots of stuff in their water. This is because as the water flows it picks up bits of dead plants, algae (single-celled organisms that photosynthesize), and other living and non-living particles from the bottom, or bed of the river. Scientists measure this stuff and call it total suspended solids (TSS). Suspended solids in a river are a hodge-podge of many different kinds of materials, but are very important to the river ecosystem, and sometimes to the floodplain along the edges of a river. Some suspended materials such as living algae or bits of broken down leaves are important because many organisms use them as a food source. However, too much sediment (dirt) in total suspended solids can bury the rocks where the organisms live. The amount of total suspended solids in a river influenced by how fast the water in the river is flowing. One way scientists measure this is as discharge, which is the volume of water that passes by a particular point over a certain amount of time. You can think about discharge as the number of cubes (one foot on each side) filled with water that pass by every second.
Reservoirs are often built along rivers by building a dam that creates a lake. As river water enters the reservoir, the dam slows down its flow rate and traps much of the water behind it. To investigate how the reservoir influences a river ecosystem, scientists measured total suspended solids and discharge in two locations along the Kalamazoo River, upstream and downstream of a reservoir.
This is an aerial photograph of the part of the Kalamazoo River sampled for this study. The river flows into the reservoir from the east (right side of the picture, upstream) towards the west (left side of the picture, downstream), where it continues on to Lake Michigan.
(A) DATA Look at the data below. See if you identify some potential patterns. Then, proceed to (B).
Date / Day of Year / TSS (mg/L)Upstream of Reservoir / TSS (mg/L)
Downstream of Reservoir
May 15 / 135 / 8.3 / 11.5
June 10 / 161 / 9.6 / 4.9
June 30 / 181 / 16.7 / 8.5
July 15 / 196 / 14.0 / 8.3
July 30 / 211 / 9.9 / 18.3
August 15 / 227 / 5.9 / 17.0
August 30 / 242 / 7.7 / 13.9
October 30 / 272 / 2.7 / 4.3
(B) Use the data given above to answer the following question:
Scientific Question:
How do total suspended solids change over the year upstream of the reservoir?
How do they change downstream of the reservoir?
Do changes in TSS upstream and downstream of the reservoir show the same or different patterns?
Evidence: Draw a line graph of the relationship between time and total suspended solids at the two locations that were sampled in the river. (Draw your graph below). The data in the graph is the evidence that you will base your claim on, just like a lawyer would in a court case.
Claim: Write a conclusion that answers the above question.
Reasoning: How does this evidence support your claim?