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.

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 Hydrological processes and water resources management in a dryland environment IV: Long-term groundwater level fluctuations due to variation in rainfall

1999 ◽  
Vol 3 (3) ◽  
pp. 353-361 ◽  
Author(s):  
J. A. Butterworth ◽  
R. E. Schulze ◽  
L. P. Simmonds ◽  
P. Moriarty ◽  
F. Mugabe
Keyword(s):  
Groundwater Resources ◽  
Water Levels ◽  
Shallow Aquifer ◽  
Balance Model ◽  
Specific Yield ◽  
Evaporative Demand ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Modelling Methods

Abstract. To evaluate the effects of variations in rainfall on groundwater, long-term rainfall records were used to simulate groundwater levels over the period 1953-96 at an experimental catchment in south-east Zimbabwe. Two different modelling methods were adopted. Firstly, a soil water balance model (ACRU) simulated drainage from daily rainfall and evaporative demand; groundwater levels were predicted as a function of drainage, specific yield and water table height. Secondly, the cumulative rainfall departure method was used to model groundwater levels from monthly rainfall. Both methods simulated observed groundwater levels over the period 1992-96 successfully, and long-term simulated trends in historical levels were comparable. Results suggest that large perturbations in groundwater levels area a normal feature of the response of a shallow aquifer to variations in rainfall. Long-term trends in groundwater levels are apparent and reflect the effect of cycles in rainfall. Average end of dry season water levels were simulated to be almost 3 m higher in the late 1970s compared to those of the early 1990s. The simulated effect of prolonged low rainfall on groundwater levels was particularly severe during the period 1981-92 with a series of low recharge years unprecedented in the earlier record. More recently, above average rainfall has resulted in generally higher groundwater levels. The modelling methods described may be applied in the development of guidelines for groundwater schemes to help ensure safe long-term yields and to predict future stress on groundwater resources in low rainfall periods; they are being developed to evaluate the effects of land use and management change on groundwater resources.

scholarly journals Groundwater Recharge Estimation Using Water Budget and Water Table Fluctuation Method in the Jakarta Groundwater Basin

2021 ◽  
Vol 1 (1) ◽  
pp. 25-38
Author(s):  
Gumilar Utamas Nugraha ◽  
◽  
Rachmat Fajar Lubis ◽  
Hendra Bakti ◽  
Priyo Hartanto
Keyword(s):  
Groundwater Recharge ◽  
Water Table ◽  
Water Budget ◽  
Annual Rainfall ◽  
Water Table Fluctuation ◽  
Groundwater Sustainability ◽  
Water Table Fluctuation Method ◽  
Groundwater Basin ◽  
Recharge Estimation ◽  
Fluctuation Method

The Jakarta Groundwater Basin is one of the groundwater basins with the highest development, economic, and business activities in Indonesia. Groundwater damage has become a major growing issue in the Jakarta groundwater basin. Intensive development has led to the overuse of groundwater in this basin. Efforts are needed to manage, protect, and conserve groundwater in this basin to support the development and economic activities sustainably. Jakarta, as the capital city of Indonesia, is located in the groundwater basin. Groundwater sustainability is determined by the amount of groundwater recharge in those basins, so knowledge of groundwater recharge is important. Groundwater is an important part of a hydrological cycle, and groundwater recharge ensures groundwater sustainability in some areas. This study aims to estimate groundwater recharge in the Jakarta groundwater basin using the water budget and water table fluctuation method. The water budget method used is Thornthwaite, Dingman, and Edijatno-Michel. The Water Table Fluctuation methods used are Dellin and Delottier. Analysis of the amount of groundwater recharge estimation is carried out using the ESPERE Version 2 software. Output data is then further analyzed using descriptive and inferential statistical approaches to determine whether there is a difference in groundwater recharge amount based on the water budget and water table fluctuation. The results show that groundwater recharge based on water budget methods is 209–885 mm/year. The estimation of the largest amount of recharge was obtained using the Edijatno-Michel approach. The smallest amount of recharge was estimated using the Dingman-Hamon method. The average recharge of groundwater in Tanjung Priok is 305 mm/year, Kemayoran is 209 mm/year, and Bogor is 885 mm/year. Only 8–15 % of the annual rainfall that converted into groundwater recharge at the study area. Based on the analysis using the water table fluctuation method, groundwater recharge in this basin has a value of 240 mm/year. The variation of the amount of groundwater recharge is caused by the pros and cons of each method. Apart from that, geological factors, land use/land cover factors, and climatic variations in this basin can affect the research results. By considering the amount of groundwater recharge, groundwater management in the Jakarta groundwater basin needs to be carried out for harmonious development and groundwater conservation.

scholarly journals Groundwater Parameter Inversion Using Topographic Constraints and a Zonal Adaptive Multiscale Procedure: A Case Study of an Alluvial Aquifer

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1899 ◽  
Author(s):  
Dimitri Rambourg ◽  
Philippe Ackerer ◽  
Olivier Bildstein
Keyword(s):  
Parameter Estimation ◽  
Groundwater Flow ◽  
Unconfined Aquifer ◽  
Water Levels ◽  
Specific Yield ◽  
Local Minima ◽  
Diffusion Type ◽  
Aquifer Parameters ◽  
Water Head ◽  
Verification Period

The identification of aquifer parameters (i.e., specific yield and hydraulic conductivity) and forcing terms (recharge) is crucial for the process of modeling groundwater flow and contamination. Inversion techniques allow the unravelling of complex systems’ heterogeneity with more ease than manual calibration by computing parameter fields through an automated minimization between simulated and measured data (i.e., water head or measured aquifer parameters). It also allows the iterative search of multiple, equally plausible solutions, depending on system complexity (e.g., aquifer heterogeneity and variability of the forcing terms such as recharge). A Zoned Adaptive Multiscale Triangulation (ZAMT) is used for parameter estimation. ZAMT is the extension of an adaptive multiscale parameter estimation procedure already applied on different field cases. This extension consists of adding constraints varying over the domain. The ZAMT dissociates the parameter grid from the calculation mesh and allows local parameter grid refinement depending on local criteria, addressing the ill-posedness of inversion problems, decreasing computation time by reducing the amount of possible solutions and local minima, and ensuring flexibility in the parameter’s distribution. Each parameter is defined per vertex of the parameter grid; it can be set with a different range of values in order to integrate more pedo-geological information and help the optimization process by reducing the number of local minima. For the same purpose, a plausibility term based on topological characteristics of the aquifer or minimal and maximal water levels is added to the objective function. Groundwater flow is described by a classical nonlinear diffusion-type equation (unconfined aquifer), which is discretized with a two-dimensional nonconforming finite element method because water head data is unsuitable to invert three-dimensional parameter fields. Therefore, flow is considered mainly horizontal, and the parameters are obtained as average values on the saturated thickness. The study area is an alluvial (unconfined) aquifer of 6.64 km², situated in the southern, Mediterranean part of France. The simulation runs with a chronicle of 191 piezometers over 7 years (2012–2019), using a calibration period of 5 years (2012–2016). The optimization threshold is set to ensure a mean absolute error below 40 cm. The ZAMT and the additional plausibility criterion were found to produce an ensemble of realistic parameter sets with low parameter standard deviation. The model is considered robust as the water head error remains at the same level during the verification period, which includes an exceptionally dry year (2017). Overall, the calibration is best near the rivers (Dirichlet boundaries), while the terraced portion of the site challenges the limits of the 2D approach and the inversion procedure.

Estimating the Temporal Distribution of Groundwater Recharge by Using the Transient Water Table Fluctuation Method and Watershed Hydrologic Model

2021 ◽  
Vol 37 (1) ◽  
pp. 95-104
Author(s):  
Il-Moon Chung ◽  
Youn Jung Kim ◽  
Nam Won Kim
Keyword(s):  
Groundwater Recharge ◽  
Water Table ◽  
Temporal Distribution ◽  
Jeju Island ◽  
Specific Yield ◽  
Recharge Rate ◽  
Water Table Fluctuation ◽  
Water Table Fluctuation Method ◽  
Reaction Factor ◽  
Fluctuation Method

HighlightsThe transient water table fluctuation method (TWTFM) is revisited.A novel application of linking SWAT model and TWTFM is suggested.A method is proposed to estimate daily groundwater recharge distribution.The method is demonstrated for the Jeju Island in Korea.Abstract. Estimating groundwater recharge remains a difficult but necessary task as part of managing available groundwater supplies. For example, the average groundwater recharge rate of Jeju Island is 54%, which is considerably higher than the inland recharge rate (~15%) in Korea. Although groundwater is the main water source of this and many other islands, quantifying temporal groundwater recharge for water resources planning remains difficult. To estimate groundwater recharge based on rainfall, a simple and straightforward method is proposed that uses an application of the Transient Water Table Fluctuation Method (TWTFM) linked with the Soil and Water Assessment Tool (SWAT). By using the computed annual percolation from the SWAT as input, two parameters (reaction factor and specific yield) could be estimated by assuming that the sum of daily recharge via the TWTFM was approximately equal to the annual percolation near the water table. This methodology was applied to the Hancheon watershed of Jeju Island, South Korea. Runoff time series data for two years (2009 and 2010) were used to calibrate SWAT and another two years of data were used to validate computed discharges from SWAT. For the calibration of the combined SWAT and TWTFM model, groundwater level data from 2009 and 2010 were used, and then data from 2011 and 2012 were used to predict groundwater recharge using the calibrated TWTFM parameters. The proposed methodology can be used as an efficient tool for estimating the temporal distribution of groundwater recharge using only groundwater data and the annual percolation rate. This methodology can be beneficial for regions where the vadose zone depth is deeply formed and temporal recharge predictions are essential for water management. Keywords: Reaction factor, Specific yield, SWAT, Transient water table fluctuation method (TWTFM).

Constraining the Magnitude and Uncertainty of Specific Yield for Use in the Water Table Fluctuation Method of Estimating Recharge

2019 ◽  
Vol 55 (8) ◽  
pp. 7343-7361 ◽  
Author(s):  
Russell S. Crosbie ◽  
Rebecca C. Doble ◽  
Chris Turnadge ◽  
Andrew R. Taylor
Keyword(s):  
Water Table ◽  
Specific Yield ◽  
Water Table Fluctuation ◽  
Water Table Fluctuation Method ◽  
Fluctuation Method

Using Groundwater Responses to Infer Recharge - Part 5

1998 ◽  
Author(s):  
D Armstrong ◽  
K Narayan
Keyword(s):  
Time Lag ◽  
Worked Examples ◽  
Unconfined Aquifer ◽  
Confined Aquifer ◽  
Case Histories ◽  
Cross Sectional ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Unconfined Aquifers ◽  
Event Basis

Analytical methods of assessing the response of groundwater levels to a range of factors, including elastic (barometric and tidal) influences in confined aquifers and recharge to unconfined aquifers due to infiltration of rain and other surface water, are presented. Responses in a confined aquifer to distant recharge events and the associated time lag is discussed. Also covered are responses to changes in storage volume resulting from direct recharge at the outcrop of an unconfined aquifer system both seasonally and on a single recharge event basis. Worked examples and case histories are used to illustrate methods of estimating the amount of recharge at different sites within a catchment. The application of vertical cross-sectional flow nets to the estimation of recharge is presented in the context of recharge/discharge profiles.

scholarly journals Hydraulic Conductivity Estimation Using Low-Flow Purging Data Elaboration in Contaminated Sites

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 898
Author(s):  
Francesco Maria De Filippi ◽  
Silvia Iacurto ◽  
Flavia Ferranti ◽  
Giuseppe Sappa
Keyword(s):  
Hydraulic Conductivity ◽  
Unconfined Aquifer ◽  
Alluvial Aquifer ◽  
Water Levels ◽  
Low Flow ◽  
Contaminated Sites ◽  
Disposal Site ◽  
Large Area ◽  
Monitoring Wells ◽  
Groundwater Characterization

Hydrogeological characterization is required when investigating contaminated sites, and hydraulic conductivity is an important parameter that needs to be estimated. Before groundwater sampling, well water level values are measured during low-flow purging to check the correct driving of the activity. However, these data are generally considered only as an indicator of an adequate well purging. In this paper, water levels and purging flow rates were considered to estimate hydraulic conductivity values in an alluvial aquifer, and the obtained results were compared with traditional hydraulic conductivity test results carried on in the same area. To test the applicability of this method, data coming from 59 wells located in the alluvial aquifer of Malagrotta waste disposal site, a large area of 160 ha near Rome, were analyzed and processed. Hydraulic conductivity values were estimated by applying the Dupuit’s hypothesis for steady-state radial flow in an unconfined aquifer, as these are the hydraulic conditions in pumping wells for remediation purposes. This study aims to show that low-flow purging procedures in monitoring wells—carried out before sampling for groundwater characterization—represent an easy and inexpensive method for soil hydraulic conductivity estimation with good feasibility, if correctly carried on.

scholarly journals A high-resolution global-scale groundwater model

2015 ◽  
Vol 19 (2) ◽  
pp. 823-837 ◽  
Author(s):  
I. E. M. de Graaf ◽  
E. H. Sutanudjaja ◽  
L. P. H. van Beek ◽  
M. F. P. Bierkens
Keyword(s):  
Groundwater Flow ◽  
Land Surface ◽  
Regional Scale ◽  
Unconfined Aquifer ◽  
Global Scale ◽  
Water Levels ◽  
Natural State ◽  
Groundwater Model ◽  
Groundwater Levels ◽  
Aquifer Systems

Abstract. Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying basic needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global-scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics, a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolutions. In this study we present a global-scale groundwater model (run at 6' resolution) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The used aquifer schematization and properties are based on available global data sets of lithology and transmissivities combined with the estimated thickness of an upper, unconfined aquifer. This model is forced with outputs from the land-surface PCRaster Global Water Balance (PCR-GLOBWB) model, specifically net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed that variation in saturated conductivity has the largest impact on the groundwater levels simulated. Validation with observed groundwater heads showed that groundwater heads are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional-scale groundwater patterns and flow paths demonstrate the relevance of lateral groundwater flow in GHMs. Inter-basin groundwater flows can be a significant part of a basin's water budget and help to sustain river baseflows, especially during droughts. Also, water availability of larger aquifer systems can be positively affected by additional recharge from inter-basin groundwater flows.

scholarly journals Ketersediaan dan Kualitas Airtanah pada Akuifer Tidak Tertekan Di Kecamatan Jawilan dan Kopo, Kabupaten Serang

2019 ◽  
Vol 33 (1) ◽  
pp. 16 ◽  
Author(s):  
Setyawan Purnama
Keyword(s):  
Groundwater Quality ◽  
Research Area ◽  
Unconfined Aquifer ◽  
Specific Yield ◽  
Groundwater Exploitation ◽  
Safe Yield ◽  
Aquifer System ◽  
Groundwater Availability ◽  
Groundwater Fluctuation ◽  
Dug Well

Tujuan dari penelitian ini adalah (1) mengetahui sistem akuifer di daerah penelitian, (2) menghitung ketersediaan airtanah pada akuifer tidak tertekan dan (3) menganalisis kualitas airtanahnya. Sistem akuifer diketahui dengan melakukan interpretasi data geolistrik. Potensi akuifer tidak tertekan dihitung secara kualitatif melalui skoring dan tumpang susun antara Peta Kedalaman Muka Airtanah, Peta Fluktuasi Airtanah dan Peta Kualitas Airtanah. Volume akuifer ditentukan berdasarkan perkalian antara luas wilayah masing-masing potensi dan tebal akuifer. Ketersediaan airtanah dihitung berdasarkan asumsi aliran airtanah statik, sedangkan hasil aman pengambilan airtanah ditentukan berdasarkan parameter fluktuasi airtanah, luas akuifer dan spesifik yield. Kualitas air dianalisis berdasarkan pengambilan sampel air pada sumur gali. Hasil penelitian menunjukkan bahwa di daerah penelitian ditemukan adanya akuifer semi tertekan dan akuifer tidak tertekan. Ditinjau dari potensinya, ketersediaan airtanah pada akuifer tidak tertekan sebesar 1.205.967.345 m3, dengan hasil aman pengambilan airtanah sebesar  54.585.307 m3/tahun. Untuk kualitas air, secara umum baik, meskipun beberapa parameter seperti kalsium, magnesium, mangan dan COD kadarnya telah melampaui baku mutu  di beberapa sampel.ABSTRACT The objectives of the research are (1) knowing the aquifer system in research area, (2) calculate groundwater availability in unconfined aquifer and (3) analysis the groundwater quality. Aquifer system is known by interpretation of geoelectric data. Groundwater potency is calculated qualitatively by scoring and overlay of Groundwater Depth Map, Groundwater Fluctuation Map and Groundwater Quality Map. Aquifer volume is calculated by multiplied area width of each potency and aquifer thickness. Amount of groundwater is calculated base on static groundwater flow assumption, whereas safe yield of groundwater exploitation is determined base on parametre groundwater fluctuation, aquifer width and specific yield. Groundwater quality are analized by groundwater samples that taken from dug well. Result of research show that there are two aquifer type in research area i.e. semi confined aquifer and unconfined aquifer. The potency of unconfined aquifer is 1.205.967.345 m3, with safe yield 54.585.307 m3/year. For groundwater quality, generally good, although some parameters have concentration exceeded the standard in some samples such as calcium, magnesium, manganese and COD.

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