Soil piping, also known as tunnel erosion, is the formation of underground tunnels as water flows through and erodes the soil beneath the surface. This process is particularly prevalent in the lateritic terrains of the Western Ghats in Kerala. The phenomenon can lead to sudden ground collapse and land subsidence, which poses a serious risk to buildings, roads, and agricultural land.
The issue first gained significant attention in Kerala when a large ground subsidence was reported in the Thirumeni village of the Kannur district in 2005. Recognizing the seriousness of the problem, the National Disaster Management Authority (NDMA) funded a research project, which led to the Kerala government officially declaring soil piping a "State-Specific Disaster." The phenomenon has been identified in many districts across the state, and ongoing research is focused on understanding its causes and developing effective mitigation strategies.