The 21st century is faced with a lot of social and environmental challenges that threaten our very existence on earth. Climate change, deforestation, biodiversity loss, pollution and institutional bottlenecks in Global Environmental Governance are but a few of the issues resource managers and policy makers have to deal with every day.

Human activity over that last 100years has been concerned with increasing productivity and improvement of livelihood through progress in technology, with little regards to its environmental legacy especially in the urban society (Painter,2003).

Soil erosion is one of the emerging environmental  issues associated with urban development. It is known as one of the leading cause of land degradation. With the jet propelling rate of urbanisation and uncertainties of climate change,the impacts of soil erosion will also be on the acceleration.

Erosion issue increases risks for public safety, and it is one of the main causes to form debris flow and collapse (Tormey, D., 2010). Besides, the erosion issue restricts the growth of city scale and slow the development speed of urban economy. For instance,  a city in China named Tianshui spends 0.5 million yuan every year on the road clearance of silt, dirt, and sewers since 1990 (Kusuda, T., 2009). As a consequence of erosion, the water capacity of city drainage system will be decreased, which leads to a reduced flood prevention capacity, resulting in many cities flooded. Also, too many sediments will reduce the capacity of flood storage and discharge in reservoir lakes (as the photo below shows). On the other hand, sediments will silt the river, which will cause adverse affects on water transportation.

LAKE SEDIMENTS

(Photographer J. HAYLEY GILLESPIE)

 

A good ESC (Erosion and Sediment Control) plan should contain two essential components including erosion control and sediment control. In this case, when the first barrier fails to retain the soil, the second barrier can arrest the sediment minimizing sediment transport from leaving the construction site. But this blog is to focus on erosion control.

 

 

 The video following shows the basic concept and mechanism of soil erosion and explains why erosion occurs more slowly when soil is paired with leaf debris or plants.

(Video Posted by funsciencedemos)

Reference:

• Tormey, D. (2010). Managing the effects of accelerated glacial melting on volcanic collapse and debris flows: Planchon–Peteroa volcano, southern andes. Global and Planetary Change, 74(2), 82-90. doi:10.1016/j.gloplacha.2010.08.003
• Kusuda, T. (2009). The Yellow River: water and life. World Scientific.