Lake Como subsidence monitoring

Lake Como subsidence monitoring

GReD collaborates with Como Municipality for monitoring the subsidence of Lake Como first basin, in order to monitor the deformation of banks and structures due to the realization of the new flood control infrastructures. GReD executes periodic surveys by means of geodetic GNSS and high-precision levelling techniques, that allow reaching accuracies of 1 mm in the estimation of the benchmark global elevations. Data elaboration involving spatial and traditional techniques requires a correct merging of information based on ellipsoidal and orthometric heights that, in order to reach the accuracy requirements, must be very accurate. At this purpose, GReD developed a dedicated tool named GPSLive, that takes into account the information coming from all the historical surveys both from GNSS and leveling, in order to better model and estimates elevations and ancillary unknowns such as geoid undulations.

Subsidence Como map

Mappa della rete

 

Statistical analysis of the time series, if correlated with other information such as water level, aquifer pressure, etc., allows understanding the land and structure behavior in response to natural and human stress applied.

The periodic surveys, started in 2012, are currently carried out every six months.

Subsidence graph

Example of height variation of one of the monitored points.