Soil and Water Bioengineering is a discipline of

civil engineering Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage ...

. It pursues technological, ecological, economic as well as design goals and seeks to achieve these primarily by making use of living materials, i.e. seeds, plants, part of plants and plant communities, and employing them in near–natural constructions while exploiting the manifold abilities inherent in plants. Soil

bioengineering Biological engineering or bioengineering is the application of principles of biology and the tools of engineering to create usable, tangible, economically-viable products. Biological engineering employs knowledge and expertise from a number o ...

may sometimes be a substitute for classical engineering works; however, in most cases it is a meaningful and necessary method of complementing the latter. Its application suggests itself in all fields of soil and

hydraulic engineering Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the mov ...

, especially for

slope In mathematics, the slope or gradient of a line is a number that describes both the ''direction'' and the ''steepness'' of the line. Slope is often denoted by the letter ''m''; there is no clear answer to the question why the letter ''m'' is use ...

and embankment stabilization and

erosion control Erosion control is the practice of preventing or controlling wind or water erosion in agriculture, land development, coastal areas, river banks and construction. Effective erosion controls handle surface runoff and are important techniques in ...

. Soil bioengineering is the use of living plant materials to provide some engineering function. Soil bioengineering is an effective tool for treatment of a variety of unstable and / or eroding sites. Soil bioengineering techniques have been used for many centuries. More recently Schiechtl (1980) has encouraged the use of soil bioengineering with a variety of European examples. Soil bioengineering is now widely practiced throughout the world for the treatment of erosion and unstable slopes.

Fields of Application and Plants for Soil Bioengineering Control Works

Soil Bioengineering methods can be applied wherever the plants which are used as living building materials are able to grow well and develop. This is the case in tropical, subtropical and

temperate zone In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

s whereas there are obvious limits in dry and cold regions, i.e. where arid, semi–arid and frost zones prevail. In exceptional cases, lack of water may be compensated for by watering or

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...

. In Europe, dry conditions limiting application exist in the Mediterranean as well as in some inner alpine and eastern European snowy regions. However, limits are most frequently imposed in alpine and arctic regions. These can usually be clearly noticed by the limited growth of woody plants (

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

, tree and shrub lines) and the upper limits of closed

turf Sod, also known as turf, is the upper layer of soil with the grass growing on it that is often harvested into rolls. In Australian and British English, sod is more commonly known as ''turf'', and the word "sod" is limited mainly to agricult ...

cover Cover or covers may refer to: Packaging * Another name for a lid * Cover (philately), generic term for envelope or package * Album cover, the front of the packaging * Book cover or magazine cover ** Book design ** Back cover copy, part of co ...

. The more impoverished a region is in species, the less suited it is for the application of bioengineering methods.

Functions and Effects of Soil Bioengineering Structures

Technical functions

*protection of soil surface from

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

by wind, precipitation, frost and flowing water *protection from rock fall *elimination or binding of destructive mechanical forces *reduction of flow velocity along banks *surface and/or deep soil cohesion and stabilization *

drainage Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic conditio ...

*protection from wind *aiding the deposition of snow, drift sand and sediments *increasing soil roughness and thus preventing avalanche release Apart from these, ecological functions are gaining in importance, particularly as these can be fulfilled to a very limited extent only by classical engineering constructions.

Ecological functions

*improvement of water regime by improved soil interception and storage capability as well as water *consumption by plants *

soil drainage Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic condition ...

*protection from wind *protection from ambient

air pollution Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...

*mechanical

soil amelioration Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

by the roots of plants *balancing of temperature conditions in near–ground layers of air and in the soil *

shading Shading refers to the depiction of depth perception in 3D models (within the field of 3D computer graphics) or illustrations (in visual art) by varying the level of darkness. Shading tries to approximate local behavior of light on the object's ...

*improvement of nutrient content in the soil and thus of

soil fertility Soil fertility refers to the ability of soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality.

on previously raw soils *balancing of snow deposits *

noise protection Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arise ...

*yield increase on neighbouring cropland

Landscaping functions

*healing of wounds inflicted on the landscape by disasters and humans (exploitation of mineral resources, construction work, deposition of overburden, tunnel excavation material, industrial and domestic waste) *integration of structures into the landscape *concealment of offending structures *enrichment of the landscape by creating new features and structures, shapes and colours of vegetation

Economic effects

Bioengineering control works are not always necessarily cheaper in construction when compared to classical engineering structures. However, when taking into account their lifetime including their service and maintenance, they will normally turn out to be more economical. Their special advantages are: *lower construction costs compared to “hard” constructions *lower maintenance and rehabilitation costs *creation of useful green areas and woody plant populations on previously derelict land *Useful for income generation The result of soil bioengineering protection works are living systems which develop further and maintain their balance by natural succession (i.e. by dynamic self–control, without artificial input of energy). If the right living but also non–living building materials and the appropriate types of construction are chosen, exceptionally high sustainability requiring little maintenance effort can be achieved.Schiechtl, H.M. and R. Stem. 1997. Water Bioengineering Techniques for Watercourse, Bank and Shoreline Protection. Trans. By L. Jaklitsch. Blackwell Scientific. Oxford, U.K. 185 pp.

References

{{Reflist Soil science Civil engineering Forestry Sustainable forest management Forestry and the environment Environmental soil science