E&ES > Geography > Research projects > Assessment of the effectiveness of geotextiles in reducing soil erosion by water

Assessment of the effectiveness of geotextiles in reducing soil erosion by water

Researcher: Drs. Smets Toon
Promotor: Prof. Dr. Jean Poesen, K.U.Leuven, Physical and Regional Geography Research Group
Co-promotor: Prof. Dr. G. Govers, K.U.Leuven, Physical and Regional Geography Research Group
Funding: European Commission (contract number: 510745)
Keywords:
geotextiles, soil erosion by water, soil conservation, rainfall simulation
Research abstract:

This research is part of the BORASSUS-Project: The Environmental and Socio-economic Contribution of Palm Geotextiles to Sustainable Development and Soil Conservation. Geotextiles are used for many engineering applications to improve soil properties. They also have a high potential for controlling soil erosion by water. On steep erodible slopes where the growing of vegetation is limited by erosive forces of rain and runoff, geotextiles can serve as a (temporarily) replacement of the vegetative cover. In this research project laboratory experiments are conducted to investigate the effect of different types of geotextiles (e.g. fig. 1) on hydrological and erosion processes.

 

Palm-leaf geotextiles

Figure 1: Palm-leaf geotextiles

Problem statement

Since the last thirty years geotextiles have played an increasing important role in civil and environmental engineering applications. Woven and nonwoven geotextiles are commonly used for application in drainage, filtration, separation and reinforcement of the soil. Because of their large potential, geotextiles are recently also used for controlling soil erosion by water. On steep slopes, for example embankments, earth banks or on steep slopes along (rail)roads natural and synthetic geotextiles can serve as an erosion control measure. They can replace or assist the vegetation which is easily damaged by the erosive forces of rainfall and overland flow. Geotextiles have some potential impacts on the hydrological and erosion processes. They can intercept raindrops and thus reduce the potential rainfall energy and rain splash detachment rates. Geotextiles can also increase infiltration rates which effectively reduce runoff rates. Because of reduced runoff volumes and rates, geotextiles are capable of decreasing sheet erosion and erosion by concentrated overland flow. By controlling soil erosion geotextiles create a stable environment in which vegetation can develop without the risk of washing out of seeds or damage to seedlings. However, data on the effectiveness of geotextiles in reducing soil erosion by water are very limited. It is unknown which types of geotextile perform better for this erosion control application, to what extent they can reduce runoff and/or decrease soil erosion rates by splash or by overland flow. Although the effects of geotextiles on these hydrological and erosion processes are not known, different types of geotextile are being used for this application.

Objectives

  1. To assess the effectiveness of geotextiles in reducing soil erosion by water through simulated rainfall experiments in the laboratory (fig. 2 & 3). The effect of geotextiles on increasing rain infiltration rates and runoff generation, reducing splash and interrill erosion, increasing the hydraulic roughness of the soil surface under overland flow and the effect on reducing soil erosion by concentrated flow will be investigated.
  2. To adapt an existing soil erosion model in order to predict the impact of geotextiles on the hydrological and erosion processes for different environmental conditions.  
Interrill erosion plot

Figure 2: Interrill erosion plot

Erosion flume

Figure 3: Erosion flume

References:
Morgan, RPC, Quinton, JN, Smith, RE, Govers, G, Poesen, JWA, Auerswald, K, Chisci, G, Torri, D, Styczen, ME, (1998). The European Soil Erosion Model (EUROSEM): A dynamic approach for predicting sediment transport from fields and small catchments. Earth Surface Processes and Landforms 23, 527-544.
Rickson, RJ, Vella, P, (1992). Experiments on the role of natural and synthetic geotextiles for the control of soil erosion. Proc. Congress "Geosintetico per le costruziono in terra - Il controllo dell'erosione", Bologna.