Hydrological Data Analysis, Forms, and
Processes
Part 1: Rivers and Streams
The U.S. Geological Survey (USGS) uses stream gauges, usually measured in cubic feet per
second (cfs), to determine if there is adequate water for irrigation purposes to encourage new
development and expansions. One of the purposes of gauging stream flow is to predict flood.
Flashfloods can have devastating effects on the environment, property, and lives. Flash flooding
is one of the major causes of natural hazard-related deaths in the United States, and is hard to
predict. The data collected by the USGS is crucial to formulating better predictive models.
Flood along the South Platte River, 2013.
USGS stream gauge (depth-only, not recording)
Task 1: Flood and Run-off
A. How do flash flood occur? Also, explain how flash floods affects areas with low infiltration
capacity vs. high infiltration capacity.
B. During or shortly after a precipitation event, what is the expected run-off event in forested
and urban environment? Draw run-off curves for each environment (below) and annotate
each to display your understanding of how overland flow changes due to surface type.
Discharge (cfs)
Forested
Time
Discharge (cfs)
Urban
Time
Task 2: Stream Order and Drainage Basin
Streams and rivers are relatively hydrodynamic compared to lakes. In a fluvial geomorphic view,
the stream system includes all surface waters in the watershed that form a network of tributary
channels and the main-stem channel. Characterizing streams in stream-order is a way to
quantify the network of streams.
First-order stream consist of the headwater tributaries starting as a single channel. When two
first-order streams join, then it becomes second-order stream. However, if a first-order stream
joins a second-order, it remains a second-order stream. When two second-order streams join,
they become a third-order stream, and so on, as displayed in this image, known as the
Horton-Strahler method:
There are several varieties of stream ordering methods that are being used today. The HortonStrahler stream ordering method is the most common and most widely used method.
A. Identify the stream orders according to the Horton-Strahler stream-order method. Place
the corresponding stream-order numbers in the circle next to each stream.
Task 3: Drainage Basin (Watershed)
A drainage basin, or watershed, is an area where all tributaries drain downslope into a body
of water such as river, lake, reservoir, wetland, or ocean. In the U.S., a majority of the States
have more than one hydrological unit or watershed. Within the main watershed, there are
smaller watersheds that drain into larger rives. For example, in this old National Atlas image,
Utah has three watersheds belonging to the: Lower Colorado, Great Basin, and California
watersheds:
Search the web, and then answer these questions.
A. How many drainage basins does Colorado have and what are they? (Provide an image
with URL citation to support your answers).
B. What does this say about the geomorphology of Colorado?
Part 2: Stream Flow and Precipitation Data Analysis
In September 2013, massive flood took place in Colorado. The moist air from the Gulf of Mexico
became trapped up against the mountains, and precipitated over the Northern Rockies region
causing severe devastation to the communities. The heavily precipitation event continued for
seven days from the 9th -15th of September. The Urban Drainage and Flood Control District
recorded the rain accumulation averaging 20 inches at one of the gauge sites in Denver Metro
area located along the South Platte River.
History: The South Platte River is one of the two principal tributaries of the Platte River and itself
a major river of the American West, located in the U.S. states of Colorado and Nebraska. Its
drainage basin includes much of the eastern flank of the Rocky Mountains in Colorado; much of
the populated region of the Colorado Front Range and Eastern Plains; and a portion of
southeastern Wyoming in the vicinity of the city of Cheyenne.
The September 2013 storm event caused rivers and channels to flood all across Colorado, and
South Platte River was one of the rivers that carried large amount of water through the Denver
Metro area. The daily average discharge of the South Platte River in August 2013 recorded by
USGS flow gauge was 197.6 cubic feet per second (cfs).
NOTE: Chatfield Reservoir releases excess water downstream to South Platte River during
increase in water level in the reservoir
The USGS flow gauge is located at I-25 and 20th street: USGS gauge station.png
Task 1: Stream Flow Data Analysis
1. For the this task, go to:
http://www.dwr.state.co.us/Surfacewater/data/detail_graph.aspx?ID=PLADENCO&MTY
PE=DISCHRG
2. Under Tabular Data on the right-hand side, and select the September 9th through 15th,
2013.
3. Uncheck the “GAG_HT” box and click “View Data”.
4. Click the Daily Ave (Flow data analysis .jpg)
5. View Data: This will show you the Data/time and Discharge values in CFS.
6. Fill out the below table with the values.
Date
Discharge (cfs)
9/9/2013
9/10/2013
9/11/2013
9/12/2013
9/13/2013
9/14/2013
9/15/2013
Average Discharge:
Maximum Discharge:
As a scientist, you must analyze and interpret the data results. Compare the results from 0915 September 2013 to 09-15 August 2013 average discharge value. Since you weren’t
around the gaging station in September 2013, what could you surmise was occurring then, as
opposed to the month previous (August 2013)? Explain possible reasons for your
interpretations?
Task 2: Precipitation Data Analysis
For this task, you will make a graph showing the rain events by plotting the September, 2013
flow (discharge) data and precipitation data which is provided by the Urban Drainage and Flood
Control District’s website.
(https://udfcd.onerain.com/sensor.php?device_id=6&site_id=14357&view_id=296&tz=US%2FM
ountain&mode=datepicker&data_start=2013-09-09+00%3A00%3A00&data_end=2013-0915+00%3A00%3A00&submit_date=OK&hours=0)
1. You will use the same storm event dates and values you got from the previous task.
2. Next, retrieve the precipitation data from: Precipitation Data_Student data.xlsx
As you can see, the data is composed of precipitation increments that the rain gauge
records several times a day. For this task, you will draw vertical lines to plot the data on
the top part of the graph for each data points. (Hint: as you draw vertical lines next to
each other, it will become thicker indicating continuous rain) Then you will use the
discharge data you already have to draw a line graph on the bottom part of the graph.
3. Plot the data on graph. In Example A, precipitation is plotted on tas vertical bars above
the horizontal line. Discharge is plotted as a curve, based on the gaging station
readings.
Precip. (in)
0.00
0.05
0.10
1400
Discharge (cfs)
1200
1000
800
600
400
200
0
7/12/13
7/13/13
7/14/13
7/15/13
Example A. Sample data plot.
Precip. (in)
South Platte River at Denver
0.00
0.05
0.10
0.15
0.20
3000
Discharge (cfs)
2750
2500
2250
2000
1750
1500
1250
1000
750
500
250
0
9/9/13
9/10/13
9/11/13
9/12/13
9/13/13
9/14/13
9/15/13
Plot your data on this graph.
What can you tell by looking at the precipitation events and discharge amounts? Are there any
correlations? Explain why or why not?
Part 3: Paleo Rivers
The current position of the rivers (and the formation of the Great Lakes) in the Northern
Hemisphere was directly influenced by the extent of glaciation during the Pleistocene Epoch.
This article explores the dramatic effect glaciation had on the course of major rivers in North
America and Europe and how history was shaped by these features. Read this article:
http://www.uwgb.edu/dutchs/research/what-if/whatif.htm
A. Can you think of your own examples of how history would have been affected by these
changes?
B. Using examples from the article as models, how do you think North American and Europe
would be affected now if the next ice age began? Give TWO good examples/scenarios for
each continent and provide sufficient support.
Example 1:
Example 2:
Part 4: Lake Formation and Types
Lakes are just as ecologically important as rivers with their own unique geological history. A lake
is a very slowly flowing open body of water in a depression in the ground that is not in contact
with the ocean. Therefore, it is important to discuss what exactly can cause there to be a
depression in the ground. There are 4 main forces that lead to depression that fill with water and
form lakes.
1. Tectonic Movements
Lakes formed by tectonic activity are usually deeper and older than other lakes. These lakes
are formed along fault lines when blocks slip below other blocks or tilt, forming depressions.
Graben lakes, like Lake Baikal in Russia, are formed when a blocks slips below the level of
the blocks on either side.
Horst lakes are formed when a fault block tilts along fault lines and leave a depression.
Horst and graben structures are indicative of tensional forces and crustal stretching. These
lakes are found in areas of tectonic activity or along fault lines.
Graben Lake (left) and Hosrt Lake (right).
2. Glacial Activity
Glaciation scours the landscape and leaves behind many different types of depressions that
become lakes. Glacial lakes tend to be the largest lakes and are most abundant in high
latitudes in the Northern Hemisphere that were glaciated during the Pleistocene Epoch.
Tarns are lakes formed by glacial scraping out of cirques, and found high up in the
mountains. They most always have a headwall and are found in an amphitheater-shaped
area.
Fjord lakes are formed in steep glacial valley when the outwash river that would normally go
to the ocean or sea is blocked by ice, till, landslide, or some other mass wasting event. Note:
a fjord lake is different that a fjord because a fjord has an outlet to the sea or ocean.
Kettle lakes form as a glacier recedes and the ice inside the glacial till eventually melts.
These are continental glaciation features and therefore found at glacial margins (or previous
glacial margins) such as the Mid-West of the US, Upstate New York, and Scandinavia.
Terminal and lateral moraine lakes form when moraine till dams the outwash.
3. Volcanic Activity
Lakes formed by volcanic activity tend to be relatively small. Lakes may form within the crater
of an active but quiet volcano, in a caldera produced by explosion and collapse of an
underground magma chamber, on collapsed lava flows, and in valleys dammed by volcanic
deposits.
4. Erosion and Dissolution
In karst regions, the limestone under the surface can dissolve and erode over time. Sinkholes
(or dolines) can form in these areas easily. Overtime, sinkholes fill in and become lakes.
They are usually small, but can be deep. Sometimes these sinkholes form under lakes and
drain them.
Task 1: Digital Landform Analysis
Now that you have a basic understanding of lake formation, look at these pictures and try to
determine what type of lake they represent.
A. What type of lake is this and how did it form?
B. What type of lake is this, and how did it form? How can you tell it’s not another type of
circular mountain lake?
C. What kind of lakes are these, and how could have they formed? What other types of
landforms could be found in the area based on how these lakes were formed?
D. Why type of lake is this, and how could it have been formed? Explain how you came to
this conclusion.
E. What kind of lake is this? Describe the process that formed this lake.
F. Based on this topographic map above, can you tell what kind of lake this is? Describe how
you came to this conclusion based on this map.
Task 2: Online Research
A. Lake Vostok is a very unique lake. Do some research and find out what makes this lake
so unique. Include a discussion of how it was formed. Do not copy and paste/plagiarize.
Put in your own words.
B. Pick two types of previously unmentioned lakes and describe how they are formed.
Include a diagram or a photo of an example of the type of lake you chose. Do not copy
and paste/plagiarize. Put in your own words.
C. Lakes are important sources of past climate information for paleoclimatologists. Explain
how lakes are used to help determine past climate and which type of lake would most
likely be used for these studies. Do not copy and paste/plagiarize. Put in your own words.