Potentiometric-surface map, October through December 1988, and water-level change map, 1983-88, of the Mississippi River alluvial aquifer in northwestern Mississippi

1993 ◽  
Keyword(s):  
Water Level ◽  
Mississippi River ◽  
Alluvial Aquifer ◽  
Water Level Change ◽  
Level Change ◽  
Potentiometric Surface ◽  
Change Map

The utility of gravity and water-level monitoring at alluvial aquifer wells in southern Arizona

Geophysics ◽  
2008 ◽  
Vol 73 (6) ◽  
pp. WA49-WA59 ◽  
Author(s):  
D. R. Pool
Keyword(s):  
Water Level ◽  
Alluvial Aquifer ◽  
Water Levels ◽  
Gravity Change ◽  
Water Level Change ◽  
Aquifer Storage ◽  
Level Change ◽  
Recharge Sources ◽  
Storage Change ◽  
Linear Correlations

Coincident monitoring of gravity and water levels at 39 wells in southern Arizona indicate that water-level change might not be a reliable indicator of aquifer-storage change for alluvial aquifer systems. One reason is that water levels in wells that are screened across single or multiple aquifers might not represent the hydraulic head and storage change in a local unconfined aquifer. Gravity estimates of aquifer-storage change can be approximated as a one-dimensional feature except near some withdrawal wells and recharge sources. The aquifer storage coefficient is estimated by the linear regression slope of storage change (estimated using gravity methods) and water-level change. Nonaquifer storage change that does not percolate to the aquifer can be significant, greater than [Formula: see text], when water is held in the root zone during brief periods following extreme rates of precipitation. Monitor-ing of storage change using gravity methods at wells also can improve understanding of local hydrogeologic conditions. In the study area, confined aquifer conditions are likely at three wells where large water-level variations were accompanied by little gravity change. Unconfined conditions were indicated at 15 wells where significant water-level and gravity change were positively linearly correlated. Good positive linear correlations resulted in extremely large specific-yield values, greater than 0.35, at seven wells where it is likely that significant ephemeral streamflow infiltration resulted in unsaturated storage change. Poor or negative linear correlations indicate the occurrence of confined, multiple, or perched aquifers. Monitoring of a multiple compressible aquifer system at one well resulted in negative correlation of rising water levels and subsidence-corrected gravity change, which suggests that water-level trends at the well are not a good indicatior of overall storage change.

Field relations among coseismic ground motion, water level change and liquefaction for the 1999 Chi-Chi (Mw= 7.5) earthquake, Taiwan

2003 ◽  
Vol 30 (17) ◽  
pp. n/a-n/a ◽  
Author(s):  
Chi-Yuen Wang ◽  
Douglas S. Dreger ◽  
Chung-Ho Wang ◽  
Daniel Mayeri ◽  
James G. Berryman
Keyword(s):  
Water Level ◽  
Ground Motion ◽  
Water Level Change ◽  
Level Change
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