tailieunhanh - Kangas - Ecological Engineering - Principles and Practice - Chapter 3

3 Soil Bioengineering The transformation of watersheds is a characteristic of human civilization. Humans transform natural landscapes into various kinds of “land use” that provide them with habitation and resources. Altered hydrology and soil erosion occur as a consequence of these transformations. | 3 Soil Bioengineering INTRODUCTION The transformation of watersheds is a characteristic of human civilization. Humans transform natural landscapes into various kinds of land use that provide them with habitation and resources. Altered hydrology and soil erosion occur as a consequence of these transformations which are problems that must be addressed. The main kinds of transformations include development of agriculture urbanization and alterations of streams rivers and coastlines. In all cases natural vegetation is removed or changed and land forms are simplified usually leveled . Society generally accepts that these direct impacts must occur to accommodate human land use but indirect impacts such as erosion are not acceptable and require engineering solutions and or management. Erosion is a major environmental impact that results in loss of agricultural productivity aquatic pollution and property damages among other problems. Although the impact of erosion has long been recognized Bennett and Lowdermilk 1938 Brown 1984 Judson 1968 it remains a challenge to society. Costs due to urban shoreline and agricultural erosion are tremendous and a major industry of businesses and technologies has arisen for erosion control. A set of ecological engineering techniques has evolved with the industry for erosion control that is the subject of this chapter. This subdiscipline has been referred to as bioengineering and it involves a combination of conventional techniques from civil or geotechnical engineering with the use of vegetation plantings Table . It is an interesting field that is growing rapidly as a cost-effective solution to erosion problems. Most workers in the field are not concerned about or perhaps not even aware of problems with overlapping meanings of the term bioengineering which is often used in other contexts Johnson and Davis 1990 . Schiechtl and Stern 1997 provide some background discussion and end up suggesting the term water bioengineering for some .