It is important to study geography so that we can understand what is going on in the real world.

1. COLUMBIA PLATEAU IN
THE USA
Geography Geomorphology
Mooka T

2. The location of the Columbia Plateau.
 The Northwest of the United States, is the geographic region of the Columbia Plateau which is
also known as Columbia Intermontane (Britannica, 2020).
 This intermontane plain is surrounded by the Northern Rocky Mountains to the east and the Sie
rra Nevada Cascade region to the west. The plateau, which covers a region of more than
100,000 square miles (260,000 square km) in Washington, Oregon, and Idaho, is well known
for its variety of landforms (Britannica, 2020).
 The most noticeable geographical feature of the interior Columbia River Basin is the Columbia
Plateau. The Columbia Plateau is located in a river basin that is primarily made up of
mountains and steep valleys (Northwest power and conservation, 2018).

3. Figure 1: An image showing the Columbia Plateau in the USA (Garofalo, 2018)

4. Figure 2: An image showing the Columbia Plateau in the USA (Garofalo, 2018)

5. The description of the Columbia Plateau. -1
• According to the Northwest power and conservation (2018), the Columbia and its
tributaries' occasionally steep river canyons cut across the Columbia Plateau, an
area of flat ground and gently rolling hills. It has a roughly triangular shape and
sides that are 250 kilometers long.
• At its lowest point, the plateau is 400 feet high. Along its edges, that height rises to
nearly 4,000 feet (1,219 meters) above sea level along its edges .
• A major agricultural region in the central Columbia River Basin, the Columbia
Plateau includes cities such as Ellensburg, Yakima, and the Tri-Cities (Northwest
power and conservation, 2018).

6. The description of the Columbia Plateau.-2
• There are heights that range from 200 to 5,000 feet (60 to 1,500 m) above sea level
despite the fact that it is entirely covered in basaltic lava flows. This is because of e
xtreme bending and faulting.
• Due to the semiarid climate, shrubs and grasses make up the majority of the vegeta
tion. The Columbia and Snake rivers drain the area (Britannica, 2020).
• Plateaus are distinct from mountain ranges in that they are extremely flat even if
they are higher in height than the surrounding topography (Molnar, 2020).

7. Figure 3: Map showing the Columbia Plateau, State of Washington, USA (Garofalo,2018)

8. HOW THE COLOMBIA PLATEAU WAS FORMED.
• The Colombia plateau also known as the Colombia basalt plain as it is placed in
between mountains is a result of eruptions that happened years ago ( Northwest power
and conservation, 2018).
• It is suspected that the eruptions that formed the plateau were from at least 6 million
years to 16 million years (Cascades volcano observation, 2018).
• It was formed by a series of eruptions which resulted in the enormous landscape that
we have now. Because it was formed by a series of eruptions the rock is laid up as the
new lava that covers over the old layer. The eruption took time to cool down which then
formed a pile or a huge rock which was not yet levelled. ( Northwest power and
conservation, 2018)
• Through erosion by rainfall, the weaker parts of the enormous rock(s) started to fall off
and a flat top started to form.

9. Figure 4: Map showing the Columbia Plateau, State of Washington, USA (Garofalo,2018)

10. CHANGES OF THE COLUMBIA PLATEAU OVER THE
YEARS.
• According to Synderi et al (2018) some roots developed and gradually went on top of the
plateau. This took years of slow progress, due to the vegetation surrounding the plateau.
• Thus the plateau got covered by grass which then turned into forest over time.
• The Colombia plateau is also known for its flood basins that have formed.
• According to Encyclopaedia Britannica, 2009, years after the formation of the plateau , a
flood wept over it and left scars more like bit of circle holes behind which got filled with
water overtime by rain. These holes grew due to erosion of water and later on got much
bigger, and thus they are known as flood basins Because of the rapid flow of water on the
plateau weaker rocks on the side got weathered and a river was formed. Which cuts through
the plateau ( Encyclopaedia Britannica, 2009).
• Because of the rapid flow of water on the plateau weaker rocks on the side got weathered
and a river was formed. Which cuts through the plateau (Encyclopedia britnnica , 2009).

11. HOW THE COLUMBIA PLATEAU MAY LOOK LIKE IN
THE FUTURE
• According to Snyderi et al., (2018) the climate has a impact on the predictions of what the Colombia might look like in
the future. The plateau is becoming more arid over time, this is by comparing past years research report and current
researches. This is also considered to be a continuing trend due to climatic factors which have a huge impact on the
exogenic process.
• As the surface is mainly composed of rock , it is highly impossible that the plateau will get bigger in size and height unless
another volcanic eruption takes place , therefore this means the landscape will either stays the same or exogenic process
might destroy it.
• It is also predicted that the invasive annual grasses will expand and the cold desert shrublands are expected as they
increase with climate change and precipitation.
• The vegetation found on the plateau will be much affected by the level of precipitation which is the demand and supply
of water This will depend much on the amount of rainfall and flow of water through the river but it is predicted that the
plateau will get lower over time as the rock gets weathered and eroded (Snyderi et al., 2018).
• The cold temperatures during winter will also have much impact as the water may find cracks in the rocks which will later
on freeze on a later stage and break the rocks, though this will take years of natural exogenic processes
• The height of the plateau might decrease with much deeper flood basins and more trees on the surface. With much
matured rivers around it.

12. POSSIBILITIES OF HOW THE COLUMBIA
PLATEAU MIGHT LOOK LIKE IN THE FUTURE
• A river between
the plateau has
already been
established, thus
the extend of its
maturity and
flow will also
have an impact
on the structure
change of the
plateau.
• Figure 6: A map (image) of how the Colombia plateau might look like as the years
go, it is not too accurate as it will depend much on the precipitation to be
received by the plateau ( Snyderi et al , 2018).

13. Reference List
 Britannica. (2020). Columbia Plateau. Encyclopedia Britannica. Available from:
https://www.britannica.com/place/Columbia-Plateau.
 Cascades volcano observation( n/a). Colombia river basalt grou stretches from oregeon to Idaho. USGS
science for a changing world. Available from: https://www.usgs.gov/observatories/cvo/columbia-river-basalt-
group-stretches-oregon-idaho
 Encyclopedia Britannica (2009, March 12). The Columbia plateau. Available from:
https://youtu.be/eShAgvcnsP0
 Garofalo M,.P. (2018). Cloud hands. Available from: http://mpgtaijiquan.blogspot.com/2018/01/columbia-
plateau-state-of-washington-usa.html
 Molnar, P. H. (2020). Plateau. Encyclopedia Britannica. Available from:
https://www.britannica.com/science/plateau-landform
• Northwest power and observation council. (2018). Colombia plateau. Available from:
https://www.nwcouncil.org/history/ColumbiaPlateau/#:~:text=The%20plateau%20formed%20bet
ween%206,the%20Deschutes%20River%20in%20Oregon.
• Snyderi, K., Evers. L.B., Chambers, J.C., Brandford, J. (2018). Effects of changing climate on the
hydrological cycle in cold desert ecosystems of the great basin and Colombia plateau. Research
gate . 71(2).