Seepage in the rock and soil is an important factor causing various geological disasters.A new quasi-distributed seepage velocity monitoring method with fiber Bragg gratings（FBGs）embedded within an internal heated alundum tube is proposed to overcome the shortcomings of the existing seepage monitoring technology.The theory of the monitoring method is described

and a new seepage monitoring sensorwith an internal heated alundumtube is invented.The relationship between the characteristic temperature value（ΔTt）and the seepage velocity（v）is deduced

and a laboratory test is conducted in sandy soil to calibrate the afore-mentioned relationship.The following conclusions are drawn from the test:（1）It is feasible to monitor seepage velocity by using the FBG sensor;（2）The newly-invented sensor shows good performance;（3）Under a given heating power

there is a linear relationship betweenΔTtand vin a certain range of seepage velocity;the larger the seepage velocityis

the smaller the characteristic temperature value will be;（4）The measurement range of seepage velocity is conditioned by the heating power;the measurement range can be increased by increasing the heating power.