Erosion control on slopes presents a persistent challenge for civil and environmental engineers. Traditional solutions—riprap, concrete channels, synthetic erosion blankets—can be effective but often carry environmental costs, including plastic pollution and habitat disruption. Biodegradable geotextiles offer an alternative that works with natural processes rather than against them.
Recent field research in Southern Switzerland provides compelling evidence for the effectiveness of these nature-based solutions.
The Research Context
The research project, conducted in Canton Ticino, Southern Switzerland, involved the application and monitoring of a bio-based,
biodegradable geotextile designed to support revegetation and erosion control on slopes exposed to a combination of unfavorable conditions, while avoiding long-term environmental impacts such as microplastic residues.
Two field case studies were established at locations with different characteristics:
• Maroggia: Differing in slope exposure, steepness, and microclimatic conditions from the second site
• Chiasso: Also presenting unique site-specific conditions
Following installation of the
geotextile in spring 2022, a comprehensive two-year seasonal monitoring program was launched.
Innovative Monitoring Approach
The research team employed an integrated, multi-method monitoring strategy:
• Terrestrial laser scanning (TLS): To detect and quantify changes in slope geometry, including erosion and deposition patterns
• UAV multispectral surveys: Achieving centimetric ground resolution (2.3–2.99 cm/pixel) for detailed vegetation assessment
• NDVI orthomosaics: To capture seasonal trends and overall greening—NDVI (Normalized Difference Vegetation Index) is a standard indicator of vegetation health and density
• Continuous data logging: Ground surface temperature and humidity sensors provided continuous data
• Field and laboratory soil analyses: To evaluate mechanical properties and soil conditions
This integrated approach enabled the detection and quantification of changes in slope geometry, vegetation cover, and microclimatic parameters throughout the study period.
Key Findings
1. No Significant Erosion Detected
TLS surveys detected localized material accumulation (soil, leaves, or vegetation mass), but no significant erosion features were observed. This indicates that the biodegradable geotextile effectively protected the slope surface during the critical establishment period.
2. Successful Vegetation Establishment
By the end of the project, both sites had achieved good vegetation cover and showed no significant erosion, indicating stable slope conditions.
Vegetation development and overall site performance were influenced by seasonal dynamics, site-specific geomorphological factors, and climatic variability. At Maroggia, greening was mainly influenced by slope geometry and microclimatic factors, whereas at Chiasso, seasonal climatic variability played the dominant role.
3. Microclimatic Benefits
Dataloggers recorded ground surface temperature and humidity values consistent with the MeteoSwiss station in Stabio, confirming that the geotextile reduced thermal extremes and preserved soil moisture.
This microclimatic moderation is critical for vegetation establishment—seedlings and young plants are particularly vulnerable to temperature stress and moisture deficits. By buffering these extremes, the geotextile creates more favorable conditions for plant growth.
4. Soil Properties Documented
Soil analyses revealed only minor differences between sites, with both exhibiting similar mechanical properties:
• Friction angle: 35–36°
• Zero cohesion
These parameters, combined with NDVI indices, were used to identify critical areas for monitoring.
5. Overall Effectiveness Confirmed
The research concluded that the biodegradable geotextile proved effective in:
• Promoting vegetation growth
• Stabilizing temperature and humidity
• Maintaining higher soil moisture
• Mitigating temperature extremes under certain conditions
The results demonstrate that the studied mats represent an effective nature-based solution for vegetation establishment, microclimatic stress reduction, and long-term slope stability.
Implications for Practice
For engineers and project owners, these findings offer several practical insights:
1. Biodegradable
Geotextiles WorkThe Swiss case studies provide field-validated evidence that biodegradable geotextiles can effectively control erosion while supporting vegetation establishment—even on slopes exposed to challenging conditions.
2. Site-Specific Factors Matter
Performance is influenced by slope exposure, steepness, microclimatic conditions, and seasonal variability. Design should account for these site-specific factors.
3. Monitoring Matters
The integrated monitoring approach—combining laser scanning, multispectral imaging, and continuous sensors—demonstrates the value of comprehensive performance assessment.
4. Microplastic Concerns Addressed
By eliminating long-term plastic residues, biodegradable geotextiles address growing concerns about microplastic pollution from construction activities.
Applications for Biodegradable GeotextilesThe Swiss research supports the use of biodegradable geotextiles for:
• Slope stabilization during vegetation establishment: Temporary protection until roots take hold
• Erosion control on sensitive sites: Where plastic residues are unacceptable
• Green infrastructure projects: Supporting nature-based solutions
• Restoration ecology: Re-establishing native vegetation on degraded slopes
• Construction site erosion control: Short-term protection with no long-term legacy
Conclusion
The Canton Ticino field studies provide robust evidence that biodegradable geotextiles can effectively control erosion, promote vegetation growth, and improve microclimatic conditions for slope stabilization. As environmental regulations tighten and sustainability expectations rise, these nature-based solutions offer a compelling alternative to conventional synthetic materials.
At HZ Geotextile, we offer natural fiber geotextiles for appropriate applications. Contact our team to discuss whether biodegradable options are suitable for your erosion control project.
