Non-invasive detection methods for subsurface drainage systems: A comparative review

The widespread use of subsurface drainage systems in agricultural landscapes over the last century has significantly enhanced land productivity, particularly in humid regions. However, many drainage systems have deteriorated or become non-functional, posing challenges in their maintenance and precise localization. Apart from this, agricultural drainage has also raised environmental concerns due to potential nutrient leaching and water quality issues over time. This review explores the state of the art of various methods to detect and map subsurface drainage networks, considering the impending complications associated with aging drainage infrastructure.

A comprehensive analysis of existing literature reveals a limited number of scientific publications addressing non-invasive drainage detection methods. Among the examined techniques - including geophysical and remote sensing-based approaches - no single method consistently demonstrates high success rates in drainage detection. Nonetheless, a combination of ground penetrating radar and unmanned aerial vehicle technologies with RGB and thermal infrared imagery emerges as a promising approach.

Looking ahead, urgent efforts are required to develop holistic and efficient detection methodologies to address the imminent challenges posed by aging drainage systems. Effective non-invasive detection methods are crucial to ensure the sustainability and productivity of agricultural landscapes affected by subsurface drainage networks.