A new distributed water pressure monitoring method for ground subsidence caused by groundwater overexploitation

• A distributed pressure sensor (DPS) is proposed for groundwater pressure monitoring. • The feasibility of the DPS was verified. • The DPS was used for pumping test and compared with traditional pressure sensor. • The DPS provides an innovative means for groundwater pressure monitoring. Groundwater pressure is a key parameter in the analysis of ground subsidence laws and disaster-causing factors. However, existing sensors make it difficult to achieve distributed and accurate measurements of groundwater pressure. This paper presents a new distributed pressure sensor (DPS) based on optical frequency domain reflectometer (OFDR) for groundwater pressure accurate measurement. The comprehensive temperature influence coefficient was proposed to eliminate the influence of temperature. Tests were conducted to verify the performance of the DPS and analyze the influencing factors. Finally, the proposed method was applied to on-site monitoring of groundwater pressure in Ningbo, China. The test results show that a smaller helically wound pitch length of the fiber optic and a larger diameter piezoresistive element are conducive to improving the sensitivity of the sensor. The on-site monitoring results indicate that the DPS has obvious advantages over traditional pressure sensors and is an innovative means for groundwater pressure measurement.