River Engineering to sustain the current flow of the Mississippi

Atchafalaya and Mississippi Rivers in Louisiana


Stephanie Payne


ES775 Advanced Image Processing


Emporia State University


The Mississippi River has gone through numerous changes over the years due to weather, seismic activity, erosion, course changes, usage and wildlife. River engineering has taken several forms. Rerouting, containment, energy generation, wildlife, and travel are all reasons for studying the changes that take place on waterways. It is difficult to change one attribute without affecting another; which means decisions have to take into account all the various factors involved.



This image is from a Landsat Satellite on April 8, 1983. It is a composite of bands 2,3, and 4. The Atchafalaya River runs through the middle of the image while the Mississippi River runs from center north across to center east. The Atchafalaya basin next to the river of the same name depicts moist soil, swamp land and is a refuge for wildlife. At the bottom of this image the Atchafalaya Delta empties water into the Gulf of Mexico.







Above is an Ortho Perspective Display of Louisiana using a composite for draping (Campagna and Warner 2009). This image was created using a SRTM DEM, an image band and the composite. The data was projected, sized, and dimensioned. After the changes were complete an image of various elevations matching the DEM file was formed (Jensen 2007).

These images are from Louisiana, USA in March 15, 2011 and May 18, 2011. The Morganza Spillway was opened on May 14, 2011 due to flooding. The navy blue is water the cream color is neutral. In the southeast corner of the images is the Mississippi River. The Center is the Morganza Spillway. Click anywhere or slide the vertical handle to see the differences in the images being compared.

before
after








The above image is a display of elevation heights of the Atchafalaya and Mississippi Rivers. After changing the palette I used IDRISI to get the DN values (measurements of elevation) and then labelled both routes to compare the two rivers. The results do show the Atchafalaya Basin steadily follows a downward path. Compared to the current path of the Mississippi it looks like it could change paths to follow the Atchafalaya Basin.


The table shows the Atchafalaya River is steadly sloping down while the Mississippi River elevations were sporadic.




Atchafalaya River Mississippi River
41 47
40 47
39 51
38 50
34 49
36 51
37 67
35
58




The Louisiana Old River Control Structure consists of three control areas including the Low Sill, Overbank, and Auxiliary structures. This image is of the control structures which are there to keep 70 percent flow to the Mississippi River for New Orleans/Baton Rouge while 30 percent of the flow is sent on to the Atchafalaya River.
5/5/1999 US Army Corps of Engineers Public Domain




In the next two band 1 images the control structures are the light green lines going across the waterways being filled by the Mississippi River. One is the Low Sill structure in 1983 while the other is from 2008 after the other two structures were built.








Conclusion:

The data from SRTM DEM datasets when imported into a GIFF and then processed with an image varied. By looking at the Ortho Perspective Display at the top of the page it is easy to see that the data is scattered and has little pattern when you look at the raw data. I did notice that the Atchafalaya River Basin area did have lower land elevations and had a declining path to the Gulf of Mexico. The Mississippi River had more of an incline or equality in the path to the Gulf of Mexico. I did not take into account all possible path variations from the spillway to the Atchafalaya Delta. So a possible variation could lead to a steeper downward slope. Possibly a program written as a path finding algorithm using the elevation amounts as input would be feasible. These might be written in comparison to a program which determines directions while driving or an artificial intelligence recursive program using matrices. Then after determining all paths each could be studied to predict a precise outcome.




References:

Jensen, John R. 2007. Remote Sensing of the Environment An Earth Resource Perspective. Prentice Hall, pp 335-352.

Campagna, David J and Timothy A. Warner. 2009. Remote Sensing with IDRISI Taiga a Beginner's Guide. Geocarto International Center.