Brushing up on Erosion Control, Article Review Example

In this article, Robbin Sotir explores the process whereby when combined as a system, vegetation and structural stability “make soil bioengineering a natural solution to erosion and flooding,” such as what occurred in Wilmington, North Carolina in the 1980’s when the backyards of expensive homes in the section called Long Leaf Hills were eroded away after the banks of a “picturesque creek that could be crossed easily by jumping” expanded due to soil depletion, creating a channel forty feet wide and ten feet deep in some areas (“Brushing Up on Erosion Control”). But today, the city of Wilmington is utilizing soil bioengineering in order to bring some stabilization to the creek banks, control flooding problems, and help restore the natural habitat of Long Leaf Creek as it was in the early 1980’s (Sotir, “Brushing Up on Erosion Control”).

As a relatively new form of technology, soil bioengineering “incorporates living plant materials to restore and protect streambanks” that have faced erosion due to industrialization and overuse of water sources, thus creating “a natural habitat and a natural filtration system for water.” Some of the techniques that are utilized to restore the natural balance includes vegetated geogrids or “live branch cuttings placed in layers with geotextile fabric wrapped around soil lifts,” and live siltation construction or the placing of living branch cuttings in trenches at an angle from the bank which offers immediate overhang and helps to trap sediments while also protecting what is known as the toe of the bank from the effects of erosion (Sotir, “Brushing Up on Erosion Control”).

Other techniques include live fascines or “sausage-like bundles of live branch cuttings placed in shallow trenches” and then partially covered over with soil and staked in place; a brushmattress, “a combinations of live cuttings and live fascines installed to provide cover and protection of streambanks); and live cribwalls or “woody cuttings inserted into a log or timber framework” (Sotir, “Brushing Up on Erosion Control”).

For the natural habitat itself, soil bioengineering has made significant differences in relation to erosion and has made life more bearable for indigenous plants and animals by creating shade and protection, “nesting and foraging sites for birds, and cover and food for some land animals” (Sotir, “Brushing Up on Erosion Control”). According to the U.S. Forest Service, the types of natural habitats in which soil bioengineering has been most beneficial are riparian ecosystems that are currently under attack by urbanization and climate change. “Any plant communities associated with water, whether they are in deserts, foothills, or mountains, are considered riparian” and provide “major creature comforts, such as food, water, and shelter,” but unfortunately “are the most misused, misunderstood, and abused portions” of the American landscape (“The Riparian Ecosystem”).

One area that Sotir examines in-depth and which is probably the most important for the reader are the long-term effects of soil bioengineering. Once the system has been put into place, whether vegetated geogrids or live fascines, little maintenance is required and if done properly lasts for a very long time. However, initial costs are high, but like other new forms of technology, it is expected that the costs will drop once cities adopt soil bioengineering as a permanent solution for erosional problems (“Brushing Up on Erosion Control”). As pointed out in the National Engineering Handbook, soil bioengineering accomplishes five specific goals–first, it “reinforces the soil through the plant roots, dampens waves and dissipates wave energy, intercepts high-water velocities, enhances water infiltration, and depletes water in the soil profile by uptake and transpiration” (“Technical Supplement 141: Streambank Soil Bioengineering”). Overall, as Sotir concludes, homeowners and businesses affected by erosion are “overwhelmingly in favor of soil bioengineering,” due mostly to “the fact that there was a creek behind their houses, and they wanted to see something” which would help to preserve the natural environment for many years to come (“Brushing Up on Erosion Control”).

Bibliography

Sotir, Robbin. “Brushing Up on Erosion Control.” Robbin B. Sotir & Associates, Inc. 2001. 24 July 2012. <http://www.sotir.com/publications/brushing_up_erosion.html>.

“Technical Supplement 141: Streambank Soil Bioengineering.” National Engineering Handbook. 2007. 24 July 2012. <http://www.nh.gov/dot/org/projectdevelopment/highwaydesign/documents/StreamlineSoilBioEng.>

“The Riparian Ecosystem.” U.S. Forest Service. 2002. 24 July 2012. <http://www.fs.fed.us/publications/soil-bio-guide>