Modeling groundwater level fluctuations in Tehran aquifer: Results from a 3D unconfined aquifer model

2019 ◽  
Vol 8 ◽  
pp. 439-449 ◽  
Author(s):  
L. Karimi ◽  
M. Motagh ◽  
I. Entezam
2017 ◽  
Vol 8 (3) ◽  
pp. 117
Author(s):  
Aditya Priyo Utomo

ABSTRAKCibabat berada dalam wilayah administratif Kecamatan Cimahi Utara, yang pada tahun 2014 memiliki tingkatpertumbuhan penduduk sebesar 25% per tahun. Peningkatan jumlah penduduk berdampak terhadap perubahantataguna lahan, yang berimbas pada berkurangnya area resapan air tanah dan meningkatnya kebutuhan pendudukakan air tanah yang mengakibatkan terjadinya fluktuasi air tanah pada daerah tersebut. Penelitian ini dilakukan untukmengetahui perbedaan fluktuasi permukaan air tanah pada daerah Cibabat, yang dipengaruhi iklim, keadaan geologi,dan kepadatan penduduk. Metode yang digunakan dalam penelitian ini di antaranya adalah geolistrik untuk intepretasigelogi bawah permukaan, pengukuran permukaan air tanah dan uji pemompaan untuk mengetahui tingkat fluktuasimuka air tanah dan besaran transmisivitas dan konduktivitas hidroliknya. Dari hasil penelitian diketahui bahwaakuifer dangkal pada daerah Cibabat merupakan akuifer bebas, dengan tingkat transmisivitas rendah yakni 0,08 / haridan konduktivitas hidrolik sebesar 1,3 10-9. Hasil pemantauan muka air tanah menunjukan fluktuasi muka air tanahyang beragam dengan tingkat penurunan terdalam berada pada bagian utara daerah penelitian yang mencapai 4,4mpada musim kemarau. Dalam jangka waktu panjang, dengan jumlah kepadatan penduduk yang terus bertambah akanmengakibatkan rusaknya keseimbangan air tanah pada daerah tersebut.Kata kunci: Cibabat, fluktuasi muka air tanah, transmisivitasABSTRACTCibabat located in the administrative area of of Cimahi Utara Distrct, which in 2014 had a population growth rateof 25% per year. The increase in population resulted in a change of land use, which impact on the reduction ofgroundwater recharge area and the increas in needs of the population will be groundwater. This study was conductedto determine differences in the groundwater level fluctuations in Cibabat area, which influenced the climate, geologicalconditions and population density. The method used in this study include the geoelectric to interpret geologicalsubsurface, groundwater level measurement and pumping test to determine the level of groundwater level fluctuationsand the amount of transmissivity and hydraulic conductivity. The result showed that the shallow aquifer in Cibabatis unconfined aquifer, with a low transmissivity level that is 0,08 / day and the hydraulic conductivity of 1,3 10-9.Monitoring results showed groundwater level fluctuations that vary with the level of the deepest decline was in thenorthern part of the research area that reached 4,4m in the dry season. In the longer term, this situation will lead tothe destruction of the groundnwater balance in the area.Keywords: Cibabat groundwater, groundwater level fluctuations, transmissivity


2021 ◽  
Author(s):  
Femi Emmanuel Ikuemonisan ◽  
Vitalis Chidi Ozebo ◽  
Olawale Babatunde Olatinsu

Abstract Lagos has a history of long-term groundwater abstraction that is often compounded by the rising indiscriminate private borehole and water well proliferation. This has resulted in various forms of environmental degradation, including land subsidence. Prediction of the temporal evolution of land subsidence is central to successful land subsidence management. In this study, a triple exponential smoothing algorithm was applied to predict the future trend of land subsidence in Lagos. Land subsidence time series is computed with SBAS-InSAR technique with Sentinel-1 acquisitions from 2015 to 2019. Besides, Matlab wavelet tool was implemented to investigate the periodicity within land displacement signal components and to understand the relationship between the observed land subsidence, and groundwater level change and that of soil moisture. Results show that land subsidence in the LOS direction varied approximately between –94 and 15 mm/year. According to the wavelet-based analysis result, land subsidence in Lagos is partly influenced by both groundwater level fluctuations and soil moisture variability. Evaluation of the proposed model indicates good accuracy, with the highest residual of approximately 8%. We then used the model to predict land subsidence between the years 2020 and 2023. The result showed that by the end of 2023 the maximum subsidence would reach 958 mm which is approximately 23% increase.


2004 ◽  
Vol 36 (4) ◽  
pp. 2057 ◽  
Author(s):  
Φ. Πλιάκας ◽  
I. Διαμαντής ◽  
A. Καλλιώρας ◽  
Χ. Πεταλάς

This paper investigates the progress of seawater intrusion within the plain area of Xylagani - Imeros, in SW part of Rhodope Prefecture, as well as the suitability of groundwater for several purposes, after qualitative valuation of groundwater samples from selective wells of the study area. The conclusions also include some managerial suggestions for the confrontation of seawater intrusion. The investigation in question took place between 1994-1997 and 2002-2003, and involves the installation of piezometric wells, geoelectric sounding measurements, grain size analyses, monitoring of the groundwater level fluctuations in selective wells, specific electrical conductivity measurements and chemical analyses of water samples from selective wells of the study area.


2019 ◽  
pp. 47-67
Author(s):  
A. A. Lyubushin ◽  
O. S. Kazantseva ◽  
A. B. Manukin

The results of the analysis of continuous precise time series of atmospheric pressure and groundwater level fluctuations in a well drilled to a depth of 400 m in the territory of Moscow are presented. The observations are remarkable in terms of their duration of more than 22 years (from February 2, 1993 to April 4, 2015) and by the sampling interval of 10 min. These long observations are suitable for exploring the stationarity of the properties of hydrogeological time series in a seismically quiet region, which is important from the methodological standpoint for interpreting the similar observations in seismically active regions aimed at earthquake prediction. Factor and cluster analysis applied to the sequence of multivariate vectors ofthe statistical properties of groundwater level time series in the successive 10-day windows after adaptive compensation for atmospheric pressure effects distinguish five different statistically significant states of the time series with the transitions between them. An attempt to geophysically interpret the revealed states is made. Two significant periods – 46 and 275 days – are established by spectral analysis of the sequence of the transitions times between the clusters.


Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 826 ◽  
Author(s):  
Wu ◽  
Hsieh

Sloping unconfined aquifers are commonly seen and well investigated in the literature. In this study, we propose a generalized integral transformation method to solve the linearized Boussinesq equation that governs the groundwater level in a sloping unconfined aquifer with an impermeable bottom. The groundwater level responses of this unconfined aquifer under temporally uniform recharge or nonuniform recharge events are discussed. After comparing with a numerical solution to the nonlinear Boussinesq equation, the proposed solution appears better than that proposed in a previous study. Besides, we found that the proposed solutions reached the convergence criterion much faster than the Laplace transform solution did. Moreover, the application of the proposed solution to temporally changing rainfall recharge is also proposed to improve on the previous quasi-steady state treatment of an unsteady recharge rate.


2016 ◽  
Vol 82 ◽  
pp. 103-115 ◽  
Author(s):  
Maminirina Joelson ◽  
Jacques Golder ◽  
Philippe Beltrame ◽  
Marie-Christine Néel ◽  
Liliana Di Pietro

Author(s):  
V. Vircavs ◽  
V. Jansons ◽  
A. Veinbergs ◽  
K. Abramenko ◽  
Z. Dimanta ◽  
...  

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