LoRa Pore Pressure Probe for Real-Time Coastal Environment Monitoring

Pore pressure monitoring in soil is used to understand subsurface hydrodynamics and the influence of infiltration and exfiltration processes influencing beach erosion and morphology in sandy soils. In this work, we develop a low-power, multisensor, long-range wireless probe applicable for short-time, frequent, real-time monitoring of pore pressure and coastal environments at various soil depths. The probe features eight pressure and temperature sensors aligned vertically on a copper pipe at different depths from the soil surface to resolve hydraulic gradients influencing sediment stability. The LoRa sensor probe features data compression and real-time data transmission for faster transmission. The sampling frequency of the developed instrument is variable to capture rapid dynamic variations in pressure according to environmental conditions. The device in this work logs the collected data onto an SD card locally in addition to wireless transmission. The fabricated waterproof probe is tested and calibrated in the laboratory using a water container at different water heights, with minor sensor-to-sensor variations. Comprehensive field tests indicate a promising wave event detection and wireless pore pressure monitoring platform suitable for various soil types, including heterogeneous soils.