The researchers have set up a cost-effective laboratory which allows controlled testing of the effects of rainfall intensity, slope gradient, soil texture, and vegetation cover on soil erosion.
Indian Institute of Technology Mandi researchers led to examine the potential of plants and fibres in combatting soil erosion. The findings of this work were recently published in the renowned Journal of Soil and Sediments, in a paper co-authored by Dr Kala Venkata Uday, Associate Professor, School of Civil and Environmental Engineering, IIT Mandi, and Dr Arnav Bhavsar Vinayak Associate Professor, School of Computing and Electrical Engineering, IIT Mandi, and their research scholars Ms. Charu Chauhan, Manvendra Singh.
Soil erosion, a complex global environmental issue, has garnered significant worldwide attention. The FAO-led Global Soil Partnership reports an annual erosion of a staggering 75 billion tonnes of soil worldwide, resulting in an estimated financial loss of US$400 billion annually. This issue hits home in India, where nearly 60 per cent of land faces soil erosion. Approximately 145 million hectares of land in the country demand immediate conservation efforts from a reported total area of 305.9 million hectares.
The researchers have established a cost-effective laboratory setup for erosion studies under simulated rainfall conditions. This setup allows controlled testing of the effects of rainfall intensity, slope gradient, soil texture, and vegetation cover on soil erosion. The team employs image analysis to quantify soil erosion and show the effectiveness of bioengineering methods in preventing it. Their study also provides insights into soil detachment, transport, and deposition mechanisms.
Dr Arnav Bhavsar Vinayak, said, “Image analysis works well for small areas like road embankments, slopes, and short natural stretches. But for bigger areas, unmanned aerial vehicles (UAVs) and remote-sensing imaging are better Our approach which uses contour detection and filling, is better than existing techniques that are often complex and costly.”
The study showed that natural vegetation roots and added fibres can work together to significantly improve soil cohesion. The type of soil, moisture content, and reinforcement collectively influence erosion rates, offering insights into soil conservation strategies. This multidisciplinary approach, combining bioengineering and image analysis, provides a promising path for addressing the challenge of soil erosion.
The researchers have shown how natural vegetation and added fibres of Indian goose grass can transform an intense erosion zone into one with practically “no erosion”. The study shows that the choice of the right material (fibre or plants) and its amount will depend on the type of erosion (caused by splashes or runoff) and the form of erosion (sheet or rill). Such research aims to make erosion control methods more effective and promote the use of natural materials.
In terms of the practical implications and future work, Dr K V Uday said, “We’ve developed a simple method to gauge the effectiveness of nature-based erosion mitigation solutions. Our method can differentiate between splash-induced erosion and runoff-induced erosion, a capability lacking in current methodologies. Also, numerical studies help enhance specific strategies for soil erosion control in larger fields.”