Introduction
The Various Indian tribes, including Illinois, Kickapoo, Ojibway, and Santee,
gave the Mississippi River its name. The word Mississippi stems from the Ojibwa word
Messipi which means ‘Big River’. Abraham wrote a letter in 1863 describing the river as
“the Father of Waters again goes unvexed to the sea.” (American Heritage Dictionary)
The Parana River name means “Mother of the Sea” and Iguazu Falls means “big water”.
The similarities of the two rivers go beyond their names. In study of hydrology,
geology, morphology, culture, history, economics, and environmental status the two
rivers are compared.
The Parana
Hydrology
The Parana River is divided into three main parts. The Upper Parana starts at the
confluence with the Iguazu River. It has high river banks and after the confluence with
the Paraguay River, the landscape becomes flat. The Middle of the Parana has a high left
bank. The right bank is lower so flooding occurs and the limits of the river become
unclear. Lower Parana is the complete opposite of the Middle the left bank is low and
experiences frequent flooding and the right bank is high. (Bonetto 1975)
Table 1.1 Rivers totaling the Rio de la Plata Drainage Basin
Rivers
Area(km2)
Length
Discharge(m3/sec)
Parana
1,510,000
4000
13,500
Paraguay
1,095,000
2,500
4,500
Uruguay
365,000
1,600
5,000
Rio de la Plata
130,000
200
3,100,000
8,300
23,000
Source. Hydrologic Regime or the Parana River and Its Influence on Ecosystems
The river narrows as the valley widens. For example, at Corrientes city the width
is 5000 meter, decreases to 3000 m at Bella Vista, 2,300 m at Santa Fe, and 2000 m at
Rosario (Bonetto 1975).
The alluvial valley of the Parana is mostly characterized as a flood plain.
Trademark signs of measurement of this composite are the sandbar plains, hindered
drainage plains and meander scroll plains. Sandbar plains are unique because of the
vegetation sandbars and large ponds, of differing orientations and depths. Hindered
drainage plains are made because of oxbow ponds and a sequence of levees.
As the river enters the ocean a delta is formed. The lower Parana has a
substantially large delta of 300 km long and covers an area of more than 15,000 km2
(Bonetto 1975).
Chemical and Physical Traits of the Parana River Water
The water in the Middle Parana is of the type with low electrolyte content, of the
subdivision “bicarbonate sodium”. It has relatively high silica and iron concentrations.
2
The buffer ability is moderate, when high carbon dioxide concentrations are present. The
pH is approaching neutral or heading toward the acid end of the range. The small
concentration of sulfates and potassium is another key factor for this type of water.
Of the Middle Parana, the Upper Parana gives 75% of the total discharge. The
waters maintain a cycle of flooding during the summer and low waters in the winter and
spring. It has low electrolytes and is classified by the bicarbonate-calcium/magnesium
type. This type indicates suspended solid concentration.
The Paraguay River contributes a high discharge of the total Middle Parana with
the remaining 25% of the Middle Parana. The waters from the Paraguay are in the
bicarbonate-chloride/sodium type. After the Bermejo River, the chemical composition is
modified. The suspended solids are increased drastically and carbonates first enter the
equation. This introduction of a new substance has an affect on the optical climate of the
waters. The turbidity values range between 7 and 205 APHA turbidity units. The
leading inorganic solid are clays. Illite is the most present, followed by montmorillonite,
kaolinite, chlorite and traces of gibbsite.
Since there is such a high presence of solids in the water there is a high rate of
physical erosion in the basin. The average is about 25 m3/km3/yr. The erosion rate is
similar to that of the Mississippi River. (Climatology and Hydrology of the La Plata
basin)
3
Table 1.2 Parana River Water Chemical Composition
Mean
Min
Max
Value
Turbidity (APHA)
65
7
205
Color (APHA)
99
38
223
pH
7.1
6.38
8.55
COD
3.90
2.40
7.50
Dissolved solids
90
46
125
CO2
12
0
45
Cl
14.3
5.0
30.5
NO3
1.27
.6
2.94
PO4
.21
.04
.59
Ca
5.4
2.3
11.4
Mg
3.4
1.5
5.2
Fe
.71
.12q
1.46
Total hardness
27
14
51
Alkalinity
.57
.40
1.50
Conductivity
88
40
140
Source. Coupling of Land and Water Systems
Morphologic
The Parana main channel is typically braided. There are segments of wide
branches woven together, containing lateral erosion and sedimentation activity forming
unstable island and sand bars. There are short portions that are single channel but they
are planimetrically stable and have not shifted or moved in the last 80 years. The wider
portions of the channel have the dimensions of 20 to 30 km long and 4 to 8 km wide.
4
The ordinary oscillation between the segments is between 5 and 10 meters. The total
surface area of the main channel is 1803 km2. (Iriondo 1988)
The modern sand bar and meandering plain is made of fine sand inside the main
channel along the whole flood plain. The plain has been permanently changed by erosion
and sedimentation. The total area is about 4150 km2 and width is 2 to 7 km. Along the
right-hand side of the flood plain there is developing meander plains in several areas. At
Santa Fe, there is the largest which is 60 km long and 6-8 km wide, on the surface it is
made of fine silty sand. (Iriondo 1988)
The evolved bar and meander deposits unit is the most recent development in
hydrological time. This unit is not changed by channel dynamics and looks like a
discontinuous belt. On the surface layer, there are signs that it was an incipient flood
morphology superimposed on the inherited pattern. The original shapes of the sand bars
are less visible. There are small active belts across the channel, forming meandering belts
with extremely high curvature radius/channel width ratios. (Iriondo 1988)
Ancient deposits are flat surfaces, which have extremely low relief. They are
hardly visible in the field. The only detectable areas are scarce swamps that are 100-300
m in diameter and irregular shape. Ancient deposits are present in Confluencia. In the
northern sector they are sunken and the southern sector they are raised. The difference in
both cases is more than 4 meters. Ancient sediments were drier that the present ones.
The deposits are thought to have been in the middle to upper Holocene period, dated from
3000 BP to 1000 BP. (Iriondo 1988)
5
1.4 Parana Flood Plain
Geomorphological unit
Area (km2)
Channel
1803
Modern sand bar and meander plain
7067
Evolved bar and meaner
1117
Ancient deposits
3253
Flood Deposits
6048
Total
19288
Source. A Comparison between the Amazon and Parana River Systems
Environmental Impacts
The Parana River has experienced many environmental changes that have molded
the river and the area surrounding the river. Deforestation, fish impacts, and sustainable
development are all major issues surrounding the current environmental situation. The
impacts are not necessarily the complete result of human interaction but they do play a
part in the whole picture.
When changes of land-cover occur, there is feedback from the vegetation,
hydrology, climate and management. The most convincing piece of evidence that there
has been a change is that the flow increased by 28% since 1970. The area has suffered
large deforestation and/or land-use change before this increase. Intensified agriculture
and industrial practices pushed for the change from coffee to soybeans and sugarcane in
the area of the Upper Parana Basin. Forests were cleared for the need of crops and
pastures. Forest area in eastern Paraguay was originally 45% and in the early 1990 it is
6
15%. The Parana Basin has also felt the changes in the deforestation from 90% in 1952
to 17% in 1985 reported Tucci and Clarke (1998). The changes in the basin have had an
impact water resource in the river. (Climatology and Hydrology of the La Plata basin)
On the Parana are two major dams; Yacreta and Itaipu. These dams have created
man made lakes which and alter the natural flow of the river. Fish that live in this area
migrate to the rivers to spawn, unlike most fish of the world, who seek to evolve in great
lakes. This is a major concern for the hydraulic engineers working on this river. The
most important species of the Parana River Ecosystem is the sabalo (Prochilodus
lineatus). The fish is a scavenger of organic matter so it is a pivotal part of the food
chain. Fish ladders, channels and elevators have been developed on dams to help with
fish passage. (Oldani 1994)
Sustainable development is construction with the needs of the future generations
in mind. This is being aware of the natural resources that we are consuming so as to not
exceed limits of that resource being replaced. This is a major concern of this area as they
consider constructing more dams and hydro-structures on the Parana.
Geology
The Paraná basin consists of many geological regions which contribute to the
characteristics of the Paraná River. In the northeastern corner of the basin is the Brazilian
shield, comprising 7.4% of the total basin area. Precambrian metamorphic rocks such as
Gneisses can be found in the belt shaped region. This area is covered with lateritic soil
and is a source of quartz and kaolinite (Iriondo, 1988).
The far western section of the basin, the Andes cordillera, is made of the Sierras
Subandinas and the Atacama highplain. Many rock types can be found here, the most
7
predominant being lutites, phyllites, and fine-grained sedimentaries. The region
contributes fine sediments such as silt and illite to the Paraná (Iriondo, 1988).
The second largest region, the Jurassic-Cretaceous area, covers 28.7% of the
basin. This area consists of tholeiitic basalts and siliceous sandstones. Lateritic soils can
be found on the surface. Quartz and kaolinite from the area are present in the basin’s
rivers (Iriondo, 1988).
The Carboniferous area near the upper Paraná is characterized by glacial and
periglacial rocks, mostly tillites, sandstone, and siltstones. This region is formed of two
belts bordering the Jurassic-Cretaceous area (Iriondo, 1988).
The Chaco-Pampa plain is the largest region of the Paraná basin covering 29.8%.
Quaternary sediments containing soluble salts such as fine sand, silt, and illites are
predominant in this area. Dissolved salts are the main contribution to the Paraná through
small rivers and groundwater seepage (Iriondo, 1988).
The Eastern Plains are formed by two areas to the left of the Paraná and Paraguay
Rivers. The northern section is called the Mato Grosso Pantanal and is composed of
alluvial cones. The southern area, Mesopotamia, is in northeastern Argentina. The
sediments of both regions are quaternary while montmorillite clays and quartz sand are at
the upper levels of the geological column (Iriondo, 1988).
Paleozoic sediments form most of the miscellaneous rocks and sediments of the
remaining 10% of the Paraná River Basin (Iriondo, 1988).
Geological region
Area(km2)
%
163 000
7.4
Brazilian shield
8
Andes cordillera
168 000
7.4
Jurassic-Cretaceous
660 000
28.7
Carboniferous
129 000
5.6
Chaco-Pampa
685 000
29.8
Eastern plains
250 000
10.9
Other
231 000
10.0
Total
2 296 000
99.8
Source Comparison between the Amazon and Parana River Systems
Culture
The area surrounding the Parana River is rich with culture, from the Jesuit
mission ruins to a modern wonder of the world. The ruins of many Jesuit missions built
during the 17th and 18th centuries lie along the Parana River. Of these are the impressive
remains of San Ignacio built in the land of the Guarani. These communities assumed
almost complete independence, as if they were individual nations. The missions reached
their peak at the beginning of the 1700’s, with 30 missions and 100,000 to 300,000 Indios
converted to Catholocism (Ramerini, 1998).
The damming of a river impacts not only the environment but also the local
culture and economy of the area. The Parana River and its tributaries have been dammed
over 50 times, including Itaipu dam, the largest hydroelectric power plant in the world.
Itaipu construction began in 1975 and the first unit began generating power in 1984.
Before inundation, archaeological remains were removed from about 300 sites but
the sites themselves, local history, and the natural landscape were lost. Thousands of
animals were caught and released in nature reserves on the banks of the reservoir where
20 million trees were planted in an effort to recreate the natural habitat (Keen, 1997).
9
Many people including the Ava-Guarani and the Mestisos were displaced due to the
creation of the power plant.
Economic
Itaipu dam, despite its negative effect on nature and culture, has helped Brazil and
Paraguay economically. Producing 12.6 million kW, Itaipu supplies 91% of electric
power in Paraguay and 25% in Brazil. The power from the dam which Paraguay does not
use is sold to Brazil.
source: www.itaipu.gov.br
More positive effects of the hydroelectric project include an increase of tourism
and recreation. The reservoir provides artificial beaches attracting many vacationers.
The dam itself, celebrated as one of the seven modern wonders of the world, has been
visited by more than 11 and a half million from 165 countries since it opened to visitors
in 1977 (Itaipu Binacional, 2001). The tourism, creation of jobs, and the production of
power have benefited the economic situation of the area
10
An additional source of wealth due to the Parana River’s tourist appeal is the
beautiful falls of Iguazu, 12 miles south of Itaipu dam. Many people from all over the
world travel to Iguazu Falls, one of the seven natural wonders of the world. The water of
the Iguazu River tumbles over a 2.5 mile long crescent-shaped cliff, creating about 275
individual cascades, some as high as 265 feet (Keen, 1997).
Historic
The middle and lower Parana Rivers flow through large and wide valleys, which
enclose many water bodies and a considerable amount of flatlands. These areas are
strongly affected by the seasonal fluctuations of water levels characteristic of the upper
Parana River. During the spring and summer discharge values increase causing flooding
of wetlands and shallow basins.
On April 28, 2003 a major flood of the Parana River began, lasting until May 10.
Twenty four people died and 161,500 were displaced as a result of the excessive rain and
flooding. The damage reached 1.5 billion dollars and affected roughly 202,800 square
kilometers. The peak discharge of the flooded Parana was at 3800 m3/s, an event for
which the populous was not prepared (“Flood Archive”, 2003). The city of Santa Fe was
mostly underwater, as well as 7.5 million acres of farmland, making it the worst flood in
the history of the city.
Other major floods of the Parana River had significantly lower discharges than
this year’s flood. In 1973 there was a flood with a 2600 m3/s discharge which caused a
lot of damage. The flood of 1998 had a discharge of 2700 m3/s, but flood-control
structures helped lessen the destruction.
11
The Mississippi
The Mississippi River is a continental river, connecting the North America’s
northern end and southern end. It is the largest
river in North America and has a length of 3,705
kilometers.1 The drainage basin is the third largest
in the world consisting of 1,245,000 square
miles.2 The Mississippi River is divided into
three parts, the headwaters, the upper and the
lower. The Mississippi River headwater begins at
Lake Itasca, Minnesota and ends at St. Anthony
Falls, Minnesota. This stretch is mostly used for
recreation and flood control. There are 11 dams,
Fig. 1: Upper Mississippi River’s dams
however none of them contain a navigation lock.
The Upper Mississippi River covers the area north
of the Ohio River at Cairo, IL to St. Anthony
Falls, Minnesota. This basin covers an area of
189,000 square miles. The Upper Mississippi
River extends 1,370 km (850 mi).2 In this section
there are 29 locks and dams to channelize the
river. The Lower Mississippi River is the
remaining stretch that lies south of the Ohio River
12
Fig. 2: Upper Mississippi River’s dams
at Cairo, IL. There are no dams in this section, however the river has been greatly
modified. Levees have been installed to control flooding, and revetments and cutoffs are
in place to channelize the river.1
Fig. 3: Mississippi River’s Basin
Fig. 4: The Mississippi River
Hydrologic
The water budget for the Mississippi River consists of a flow of about 130 billion gallons
per day that is received and then discharged. 127 billion gallons per day come from
precipitation and 2.4 billion gallons per day arrive from the surface-water inflow. 50
billion gallons per day are discharged through the surface water and 79 billion gallons per
day are evaporated through evaportranspiration.3
Geologic
The Mississippi River’s width at its narrow stretch is 20 to 30 ft wide. Behind the dams
and in Lake Onalaska the River width is 4 miles. The shallow parts of the River are less
then 3 ft deep. The deepest stretch is 200 ft between Governor Nicholls Wharf and
Algiers Point in New Orleans. The Mississippi River carries about 159 million tons of
sediment in one year. This is also sediment from the tributaries entering the Mississippi
River.4 The vegetation in the basin area of the Mississippi River consists of forested
13
ecosystems, grasslands, and agricultural land. The land is becoming more and more
agricultural. This changes the ecosystem and leads to more soil erosion. The soil type
beneath the flood plains and the Mississippi River is an alluvial aquifer. This consists of
less- permeable silts, coarse sand and gravel of the Mississippi River alluvium.5
Morphologic
In 1850, the widespread damage of flooding encouraged the nation to develop and control
the river.1 Cutoffs were installed to shorten the river. Revetments were installed to control
the meandering of the river. In the following table one can see a comparison with each
river segment’s total floodplain acreage and the percentage of floodplain that has been
isolated from the main river channel.6
Presently there are 40 dams on the Mississippi River and they helped direct the flow. A
routine dredging helps realign the channel depth. This allows ocean vessels to travel on
the Mississippi as far north as Baton Rouge, Louisiana. All of these helped stabilize and
protect the riverbanks and allowed for easier navigation through the river.
14
Environmental
The water quality and ecosystem in the Mississippi River is a reflection of the climate,
environment, urbanization, industrialization, and agricultural activities from the
surrounding area. The Mississippi River’s ecosystem is a multiple – use resource for
humans. As these resources are utilized more and more, the inputs of sediment, nutrients
and chemicals have increased. Over sedimentation and excess nutrients causes
eutrophication and buries benthic species. Also the man made structures such as the
levees and dams interact with the ecosystem. The environmental characteristics of the
river have been modified to allow for of the adaptation of the Mississippi River.
Historical
In order to get a full historical view of the Mississippi River we must travel back
in time to the most resent ice age. The Wisconsin glaciation started about 75,000 years
ago. The earth’s climate started to warm up about 12,000 years ago, this warming
resulted in huge glacial melts. As the mile to two-mile thick ice melted huge flows ran
through the central portion of North America. The large flows dug banks that were 250
feet deeper than the banks of today.
Fig. A Paddlefish
During the beginning of this era of frozen glaciers the fish that lived in the water
moved south to the warmer water. When the northern ice started to melt the fish moved
back up the river. Some of these fish that made the multi millennium migration are still
15
in the river today include, long-nosed and short-nosed gar, sturgeon and paddlefish.
(Nissen, 1996)
Cultural
The Mississippi River used by millions of people every day, if it weren’t for this
fresh water connection of the Golf of Mexico and Minnesota life in the mid west would
be very different. Each year more than 90 tons of cargo are moved from Saint Paul to
Saint Louis. The cargo includes grain, petroleum and building products. (American
Rivers, 2003). Other uses of the river include recreation, industrial, water sanitation and
energy plant cooling. Whether you are a farmer and your crop is sent world wide via the
Mississippi or you enjoy fishing and boating the river or you use the power produced
from a plant that is cooled by the Mississippi waters, if you live in the Midwest you most
likely are effected by the Mississippi River.
Economic
Many of the listed social aspects of the Mississippi River have large contributions
to the economic value of the river. Recreational use and tourism accounts for 10 billion
dollars each year. Recreation only plays a small roll in the total budget of the
Mississippi. It is hard to put a value on the water that is used for cooling in industrial
uses.
16
Fig. Barge Traffic through a lock.
The major economic factor of the Mississippi River is its value for transportation of
goods, upstream and downstream as the beginning and ending of world trade. Every year
around 100 billion dollars of commerce flows down the river. (Tara, 2003)
The river also supplies jobs of all forms, boat engineers, park rangers, lobbyist for
river protection, and lobbyist for river water use in industry. All of these jobs increase
the financial value of the Mississippi River.
Comparison of Mississippi and Parana and Conclusion
3.3 Average concentration and transport of Carbon DOC
River site
Discharge Area Runoff
(km3
Concentration d.w.
(mm/year) range (mg/l)
/year
Flux
mean (106
t/year)
17
t/km2/year source
Parana
480
2800
171
-20
6.1
2.8
1
Depetris
and
Paolini
Mississippi 439
3267
154
8
3.5
1.1
Leenheer
1982
Source. Scope 42 Biogeochemistry of Major World Rivers
1.1 Drainage area, total discharge volume and carbon fluxes comparing the Mississippi
and Parana
River/Station
Mississippi/ Bel
Area
Volume
TDS x
TSS x
DOC x
POC x
TOC x
DIC x
(km3/year)
106
106
106
106
106
106
t/year
t/year
t/year
t/year
t/year
t/year
3.22
410
142.0k
296.0k
3.54
.84
3.64
11.6 4
2.8
470
38.55
80.05
5.95
1.35
7.25
3.05
Chase
Parana/ Sta. Fe
Source. Scope 42 Biogeochemistry of Major World Rivers
The comparison between the Mississippi and the Parana can reveal starch
similarities. The two rivers have comparable lengths, volume, discharge, and area. From
physical standpoint they are very similar, but on the morphologic standpoint differences
occur. The Mississippi has had more interference from hydrologic structures and has
transformed into a sequence of man made lakes. The Mississippi is controlled mainly by
man’s intervention. The Parana, on the other hand, has not had so much influence by
man. The river has minimal structures on it at this point but there are research and
projects looking into the development of more dams for hydropower. The Mississippi
18
can provide some clues into the future of the Parana if more dams are to be built.
Through the study of many aspects of the Mississippi and Parana River we have been
able to arrive at conclusions about the geology, morphology, environmental status,
culture, history, economic, and hydrologic.
19
Work Cited
Bonetto, Argentino A. “Hydrologic Regime of the Parana River and Its Influence
on Ecosystems.” New York 1975: 175-196
“Climatology and Hydrology of the La Plata basin”
www.atmos.umd.edu/~berbery/laplata/ retrieved on 4 June 2003.
Depetris, Pedro. “Biogeochemical Aspects of South American Rivers: The
Parana and the Orinoco” www.icsu-scope.org/downloadpubs/scope42/shapter05.html
retrieved on 3 June 2003.
Iriondo, M.H. “A Comparison Between the Amazon and Parana”. Parana,
Argentina 1988:77-92
Oldani, Robeto. “Environmental and Social Dimensions of Reservoir
Development and Management in the La Plata River Basin” Nagoya Japan 1994:59-65.
Ramerini, M. (1998). The Jesuit Missions in South America. Retrieved June 4, 2003,
from http://www.geocities.com/Athens/Styx/6497/jesuits.html
Where the water flows: Parana River watershed. (n.d.). Retrieved June 4, 2003, from
http://www.col-ed.org/echo2002/Watershed%20Issues%20Webguide/linkslessplan/
index_watershed.html
Active Archive of Large Flood Events. (2003). Retrieved June 5, 2003, from Dartmouth
Flood Observatory Web site: http://www.dartmouth.edu/~floods/index.html
20
Human Impacts on the Pantanal. (n.d.). Retrieved June 5, 2003, from University of
Vermont Web site: http://www.uvm.edu/~awakefie/snr260/humanimpact.html
Keen, C. (1997). Greatest places physical geography: Iguazu falls. Retrieved June 5,
2003, from http://www.greatestplaces.org/notes/iguazu.htm
Itaipu Binacional: 93.4 billion kWh. (2001). Social Communication Council
“Mississippi” 2000. www.bartleby.com/61/35/m0343500.html American Heritage
Dictionary fourth edition. Retrieved on 4 June 2003.
Tara, (2003). Mississippi River. Retrieved June 5, 2003, from
http://www.tarawildlife.com/river.shtml
American Rivers, (2003). The Mississippi River Retrieved June 6, 2003, from
http://www.americanrivers.org/mississippiriver/misscommerce1.htm
Nissen Ruth, (1996) Glaciers Left Their Mark on the Mississippi River, Retrieved June 6,
2003 from http://www.greatriver.com/Ice_Age/glacier.htm
21