scholarly journals Changes In Groundwater Levels, Spring Discharge, and Concentrations of Saline and Rock-Matrix Indicators of the Floridan Aquifer System, Florida (1991–2011)

10.35256/b70 ◽  
2021 ◽  
Keyword(s):  
Spring Discharge ◽  
Rock Matrix ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Floridan Aquifer

Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

2018 ◽  
Vol 7 (4) ◽  
pp. 191
Author(s):  
Sherwan Sh. Qurtas
Keyword(s):  
Unconfined Aquifer ◽  
Middle Part ◽  
Water Levels ◽  
Specific Yield ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Water Table Fluctuation Method ◽  
Recharge Estimation ◽  
Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

Summary of hydraulic properties of the Floridan Aquifer system in coastal Georgia and adjacent parts of South Carolina and Florida

2005 ◽  
Author(s):  
John S. Clarke ◽  
David C. Leeth ◽  
DaVette Taylor-Harris ◽  
Jaime A. Painter ◽  
James L. Labowski
Keyword(s):  
South Carolina ◽  
Hydraulic Properties ◽  
Aquifer System ◽  
Floridan Aquifer

scholarly journals Depletion of groundwater resources under rapid urbanisation in Africa: recent and future trends in the Nairobi Aquifer System, Kenya

2020 ◽  
Vol 28 (8) ◽  
pp. 2635-2656
Author(s):  
Samson Oiro ◽  
Jean-Christophe Comte ◽  
Chris Soulsby ◽  
Alan MacDonald ◽  
Canute Mwakamba
Keyword(s):  
Negative Impact ◽  
Groundwater Resources ◽  
Climatic Data ◽  
Groundwater Abstraction ◽  
Management Scenarios ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Future Evolution ◽  
Level Data ◽  
Groundwater Assessment

AbstractThe Nairobi volcano-sedimentary regional aquifer system (NAS) of Kenya hosts >6 M people, including 4.7 M people in the city of Nairobi. This work combines analysis of multi-decadal in-situ water-level data with numerical groundwater modelling to provide an assessment of the past and likely future evolution of Nairobi’s groundwater resources. Since the mid-1970s, groundwater abstraction has increased 10-fold at a rate similar to urban population growth, groundwater levels have declined at a median rate of 6 m/decade underneath Nairobi since 1950, whilst built-up areas have increased by 70% since 2000. Despite the absence of significant trends in climatic data since the 1970s, more recently, drought conditions have resulted in increased applications for borehole licences. Based on a new conceptual understanding of the NAS (including insights from geophysics and stable isotopes), numerical simulations provide further quantitative estimates of the accelerating negative impact of abstraction and capture the historical groundwater levels quite well. Analysis suggests a groundwater-level decline of 4 m on average over the entire aquifer area and up to 46 m below Nairobi, net groundwater storage loss of 1.5 billion m3 and 9% river baseflow reduction since 1950. Given current practices and trajectories, these figures are predicted to increase six-fold by 2120. Modelled future management scenarios suggest that future groundwater abstraction required to meet Nairobi projected water demand is unsustainable and that the regional anthropogenically-driven depletion trend can be partially mitigated through conjunctive water use. The presented approach can inform groundwater assessment for other major African cities undergoing similar rapid groundwater development.

scholarly journals Seismically induced changes in groundwater levels and temperatures following the ML5.8 (ML5.1) Gyeongju earthquake in South Korea

2021 ◽  
Author(s):  
Soo-Hyoung Lee ◽  
Jae Min Lee ◽  
Sang-Ho Moon ◽  
Kyoochul Ha ◽  
Yongcheol Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Groundwater Level ◽  
Seismic Waves ◽  
Groundwater Resources ◽  
Fluid Pressure ◽  
Water Levels ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Gyeongju Earthquake

AbstractHydrogeological responses to earthquakes such as changes in groundwater level, temperature, and chemistry, have been observed for several decades. This study examines behavior associated with ML 5.8 and ML 5.1 earthquakes that occurred on 12 September 2016 near Gyeongju, a city located on the southeast coast of the Korean peninsula. The ML 5.8 event stands as the largest recorded earthquake in South Korea since the advent of modern recording systems. There was considerable damage associated with the earthquakes and many aftershocks. Records from monitoring wells located about 135 km west of the epicenter displayed various patterns of change in both water level and temperature. There were transient-type, step-like-type (up and down), and persistent-type (rise and fall) changes in water levels. The water temperature changes were of transient, shift-change, and tendency-change types. Transient changes in the groundwater level and temperature were particularly well developed in monitoring wells installed along a major boundary fault that bisected the study area. These changes were interpreted as representing an aquifer system deformed by seismic waves. The various patterns in groundwater level and temperature, therefore, suggested that seismic waves impacted the fractured units through the reactivation of fractures, joints, and microcracks, which resulted from a pulse in fluid pressure. This study points to the value of long-term monitoring efforts, which in this case were able to provide detailed information needed to manage the groundwater resources in areas potentially affected by further earthquakes.

scholarly journals Characterization of earth fissures in South Jiangsu, China

2015 ◽  
Vol 372 ◽  
pp. 249-253 ◽  
Author(s):  
S. Ye ◽  
Y. Wang ◽  
J. Wu ◽  
P. Teatini ◽  
J. Yu ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Earth Fissure ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Earth Fissures ◽  
The Earth ◽  
Cumulative Length ◽  
Differential Land Subsidence

Abstract. The Suzhou-Wuxi-Changzhou (known as "Su-Xi-Chang") area, located in the southern part of Jiangsu Province, China, experienced serious land subsidence caused by overly exploitation of groundwater. The largest cumulative land subsidence has reached 3 m. With the rapid progress of land subsidence since the late 1980s, more than 20 earth fissures developed in Su-Xi-Chang area, although no pre-existing faults have been detected in the surroundings. The mechanisms of earth fissure generation associated with excessive groundwater pumping are: (i) differential land subsidence, (ii) differences in the thickness of the aquifer system, and (iii) bedrock ridges and cliffs at relatively shallow depths. In this study, the Guangming Village Earth Fissures in Wuxi area are selected as a case study to discuss in details the mechanisms of fissure generation. Aquifer exploitation resulted in a drop of groundwater head at a rate of 5–6 m yr−1 in the 1990s, with a cumulative drawdown of 40 m. The first earth fissure at Guangming Village was observed in 1998. The earth fissures, which developed in a zone characterized by a cumulative land subsidence of approximately 800 mm, are located at the flank of a main subsidence bowl with differential subsidence ranging from 0 to 1600 mm in 2001. The maximum differential subsidence rate amounts to 5 mm yr−1 between the two sides of the fissures. The fissure openings range from 30 to 80 mm, with a cumulative length of 1000 m. Depth of bed rock changes from 60 to 140 m across the earth fissure. The causes of earth fissure generation at Guangming Village includes a decrease in groundwater levels, differences in the thickness of aquifer system, shallow depths of bedrock ridges and cliffs, and subsequent differential land subsidence.

scholarly journals Ongoing research on the pumping-induced land deformation in the Aguascalientes Valley: an analysis of the recent data of vertical deformation, groundwater level variations and local seismicity

2020 ◽  
Vol 382 ◽  
pp. 99-102
Author(s):  
Martin Hernandez-Marin ◽  
Ruben Esquivel-Ramirez ◽  
Mario Eduardo Zermeño-De-Leon ◽  
Lilia Guerrero-Martinez ◽  
Jesus Pacheco-Martinez ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Close Association ◽  
Active Faults ◽  
Vertical Deformation ◽  
Ongoing Research ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Critical Information ◽  
Aguascalientes Valley ◽  
Low Magnitude

Abstract. In the Aguascalientes valley, middle Mexico, the demand of groundwater from the local aquifer system was suddenly increased after the late 1970s. Since then, several related problems have been occurring or become critical such as land subsidence, ground fissuring, and low-magnitude earthquakes. The most recent data of vertical deformation from PSInSAR, groundwater levels, and earthquakes, has provided critical information regarding the relationship amongst all these processes. In particular, that related to land subsidence, earth fissuring and seismicity. Regarding this, more satellite imagery and data from GPS stations are being revised as a possibility of a more generalized vertical deformation derived with low-magnitude seismicity. A particular seismic event recorded on 6 April 2019 has revealed critical information on the close association between vertical displacements occurred in active faults and low-magnitude seismic events.

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