Search results
Results from the WOW.Com Content Network
The dam monitoring system checks the level of the water because this creates different pressures on the dam, also in relation to the air and water temperature. All these parameters are controlled and compared with the deformation and stress applied on the structure of the dam, measured with extensimeter, pendulum, reverse pendulum, piezometer, etc.
Land subsidence is a global issue and has different causes. Some are natural, like earthquakes , and some are caused by humans. In the United States, land subsidence from over pumping has affected 45 states and accounts for changes in over 17,000 square miles of land which is an area almost 10 times the size of Glacier National Park in Montana ...
These sensors work by sending in small electromagnetic waves into the subsurface level, and receiving information as these waves are returned. [12] Key components of studying land subsidence in the Central Valley include large and small scale monitoring, studying topography in relation to groundwater, and a multi-agency approach.
Subsidence frequently causes major problems in karst terrains, where dissolution of limestone by fluid flow in the subsurface creates voids (i.e., caves).If the roof of a void becomes too weak, it can collapse and the overlying rock and earth will fall into the space, causing subsidence at the surface.
Drivers, processes, and impacts of sinking cities [1]. Sinking cities are urban environments that are in danger of disappearing due to their rapidly changing landscapes.The largest contributors to these cities becoming unlivable are the combined effects of climate change (manifested through sea level rise, intensifying storms, and storm surge), land subsidence, and accelerated urbanization. [2]
The Westbay casing system is designed to allow the monitoring of multiple discrete levels in a single borehole. The casing comes in two different sizes, the MP38 system (38 mm, 1.5-inch) and MP55 system (55 mm, 2.25-inch). One single string of water-tight Westbay casing sections is installed in the borehole.
Nearly half of China’s urban areas comprising 29% of the country’s population are sinking faster than 3 millimeters per year, according to a new study.
Aquifer compaction is a significant concern along with pumping-induced land subsidence. A large portion of the groundwater storage potential of many aquifers can be significantly reduced when longterm groundwater extraction, and the resulting groundwater level decline, causes permanent compaction of fine sediment layers (silts and clays).