scholarly journals The Significance of Groundwater Flow Modeling Study for Simulation of Opencast Mine Dewatering, Flooding, and the Environmental Impact

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 848 ◽  
Author(s):  
Jacek Szczepiński
Keyword(s):  
Environmental Impact ◽  
Groundwater Flow ◽  
Mine Drainage ◽  
Numerical Models ◽  
Open Pit ◽  
Climate Conditions ◽  
Aquifer System ◽  
Flow Models ◽  
Mine Dewatering ◽  
Cyclic Changes

Simulations of open pit mines dewatering, their flooding, and environmental impact assessment are performed using groundwater flow models. They must take into consideration both regional groundwater conditions and the specificity of mine dewatering operations. This method has been used to a great extent in Polish opencast mines since the 1970s. However, the use of numerical models in mining hydrogeology has certain limitations resulting from existing uncertainties as to the assumed hydrogeological parameters and boundary conditions. They include shortcomings in the identification of hydrogeological conditions, cyclic changes of precipitation and evaporation, changes resulting from land management due to mining activity, changes in mining work schedules, and post-mining void flooding. Even though groundwater flow models used in mining hydrogeology have numerous limitations, they still provide the most comprehensive information concerning the mine dewatering and flooding processes and their influence on the environment. However, they will always require periodical verification based on new information on the actual response of the aquifer system to the mine drainage and the actual climate conditions, as well as up-to-date schedules of deposit extraction and mine closure.

scholarly journals PERENCANAAN SISTEM PENYALIRAN TAMBANG PIT 35 PT MULTI HARAPAN UTAMA BLOK TELUK DALAM OPERATION

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Anggriano Sagar ◽  
Agus Triantoro ◽  
Uyu Saismana ◽  
Zuan Eka Prawita
Keyword(s):  
Mine Drainage ◽  
Open Pit ◽  
Mine Dewatering

PT Multi Harapan Utama (PT MHU) selaku pemegang PKP2B untuk melakukan kegiatan penambangan batubara yang beroperasi pada daerah tambang di Teluk Dalam. Penambangan batubara PT MHU menggunakan sistem tambang terbuka (open pit) yang pada kegiatan penambangan akan menghasilkan daerah bukaan tambang pada permukaan kerja (front) penambangan, sehingga selama kegiatan penambangan akan menghadapi masalah air, kondisi inilah yang mengharuskan PT MHU melakukan penanganan masalah air tambang (mine drainage dan mine dewatering). Salah satu cara yang digunakan untuk mengeluarkan air dari dalam tambang ialah dengan sistem pemompaan akan tetapi air yang akan dipompakan sudah bercampur dengan material lumpur. Sedangkan cara untuk mencegah air limpasan masuk ke area penambangan dapat diatasi dengan pembuatan saluran.Metode yang digunakan dalam penelitian ini adalah dengan menganalisis kemampuan pompa berdasarkan Head atau julang yang ada di tiap triwulan penambangannya yang berbeda-beda sehingga dapat memberikan rekomendasi pemilihan unit pemompaan yang baik atau sesuai dengan kebutuhan tambangnya. Pemilihan unit pompa dilakukan terhadap 6 (Enam) tipe pompa merek Multiflo, meliputi Mf-120, Mf-140, Mf-160, Mf-180, Mf-290, Mf-360. Setelah dilakukan penelitian dan perhitungan pemilihan unit pompa yang digunakan, maka hasil yang diperoleh adalah pada Triwulan I menggunakan pompa tipe MF-140 dengan lama waktu pemompaan 3 hari, Triwulan II menggunakan pompa tipe MF-180 dengan lama waktu pemompaan 2 hari, Triwulan III menggunakan pompa tipe MF-180 dengan lama waktu pemompaan 2 hari, dan Triwulan IV menggunakan pompa tipe MF-180 dengan lama waktu pemompaan 2 hari. Selain itu pembuatan dimensi sumuran yang di asumsikan mampu dalam menampung jumlah debit air hariannya selama 1 tahun penambangan atau 4 (empat) triwulan. Kata-kata kunci: Mine Dewatering, Debit, Pompa, Dimensi   

scholarly journals An analytical study of groundwater fluctuations in unconfined leaky aquifers induced by multiple localized recharge and withdrawal

2013 ◽  
Vol 15 (3) ◽  
pp. 394-407 ◽  
Keyword(s):  
Groundwater Flow ◽  
Numerical Models ◽  
Temporal Distribution ◽  
Neumann Boundary ◽  
Unconfined Aquifer ◽  
Flow Equation ◽  
Aquifer System ◽  
Fourier Cosine ◽  
Induced Flow ◽  
Vertical Leakage

<p>Commonly used analytical methods for assessing the effects of recharge and withdrawal on the groundwater flow system are based on an idealistic assumption that the aquifer&rsquo;s base is fully impervious. In reality, the hydrostratigraphic conditions are often complex and involve leakage induced flow between aquifer and the confining layers. In this study, a simple analytical procedure is presented for determining the spatial and temporal distribution of water head in an unconfined aquifer system due to multiple localized recharge and withdrawal at time-varying rates. A new transient function is introduced that can conveniently approximate the rising and recession limbs of any single recharge hydrograph. Solution of linearized two-dimensional groundwater flow equation under Dirichlet and Neumann boundary conditions is obtained using finite Fourier cosine transform with analytic inversion. The study has at least one clear advantage over the existing solutions that it accounts for the vertical leakage in water table buildup and drawdown analysis. A computational example demonstrates that the leakage induced flow plays an important role in recharge and withdrawal processes of unconfined aquifer system. The model results can be used for estimating aquifer&rsquo;s hydraulic properties and validation of numerical models.</p>

scholarly journals Groundwater Flow Modeling in Chitwan Dun Valley (Between Narayani River and Lothar Khola), Nepal

2019 ◽  
Vol 24 (2) ◽  
pp. 30-38
Author(s):  
Rita Bhandari ◽  
Dinesh Pathak
Keyword(s):  
Numerical Model ◽  
Groundwater Flow ◽  
Groundwater Modeling ◽  
Flow Direction ◽  
Flow Modeling ◽  
Aquifer System ◽  
Flow Equations ◽  
Flow Models ◽  
Future Behavior ◽  
Fence Diagram

 Models are simplification of reality to investigate certain phenomena or to predict future behavior and always tries to generate scenario that is close to the real condition. Groundwater flow models are computer models generated through using established flow equations that simulate and predict aquifer conditions. The result of groundwater modeling is used for groundwater management and remediation. In the present study, hydrostratigraphic units were identified through interpreting the lithological logs of the drilled wells then fence diagram was prepared with three major aquifer horizons, namely unconfined, shallow confined and deep confined aquifers. In addition, hydrogeologic data were integrated to develop a conceptual hydrogeologic model of the aquifer system of the Chitwan Dun valley, which was the basis for the development of the numerical model. The aquifer system was modeled numerically using MODFLOW-2005 numerical modeling, which was further calibrated and an acceptable numerical model was obtained which showed different flow direction in each aquifer layer. The model was validated by comparing the observed and simulated heads. The result shows that in each of the aquifer layers, the general flow direction is towards west and south-west.

scholarly journals Pemodelan airtanah dan Neraca Airtanah Dampak Penambangan Batubara Open Pit pada Lipatan Sinklin di Daerah Muara Lawa, Kabupaten Kutai Barat, Provinsi Kalimantan Timur

2019 ◽  
Vol 2 (2) ◽  
pp. 69-83
Author(s):  
Shalaho Dina Devy
Keyword(s):  
Land Use ◽  
Groundwater Flow ◽  
Mining Area ◽  
Open Pit ◽  
Base Layer ◽  
Land Use Impacts ◽  
Visual Modflow ◽  
Aquifer System ◽  
Groundwater Availability ◽  
Hydrogeological Study

Ch a n g e s in land use impacts on groundwater availability both in quality and quantity. Study of geological, hydrogeological conditions, hydrological, hydrogeological boundary conditions contribute to determine the presence of groundwater in the groundwater basin and determine the natural groundwater flow modeling patterns. Location of the study are in Muara Lawa, including the formation Pulaubalang, Pamaluan, and Balikpapan on Lampanan syncline structure. Exploration drilling results indicate, that the hydrogeological study area into the aquifer system of folded sedimentary rocks consisting of seven aquifer layers alternating between akuitar, aquifers, and the base layer in the form of akuiklud. The area bounded by the limits of the model study of surface water in two major rivers, the Lawa River (east) and the Perak River (west), as well as the groundwater divide with the highest head (north and south. The results of the analysis of the type of regional aquifers aquifer models including the category of semi depressed with aquitards dominance in the surface layer. The pattern of groundwater flow and head height can be predicted by modeling using Visual Modflow. There is an increase zone budget is almost five times higher than the natural condition to the active mining conditions, particularly in the green zone, that of the natural conditions of 1,502 m3 day-1 to 12,930 m3 day-1 in the active mining. This is due, in the mining area there is a change in land use and hidrostratigrafi, namely the formation of pits that reach depths of 70 meters.

SELECTED METHODS OF TESTING HYDROGEOLOGICAL FEATURES OF ROCKS AS A SUPPORT FOR GROUNDWATER FLOW MODELLING NEAR A RECLAIMED OPEN PIT

2018 ◽  
Vol 471 ◽  
pp. 117-126
Author(s):  
Katarzyna NIEDBALSKA ◽  
Przemysław BUKOWSKI ◽  
Iwona AUGUSTYNIAK
Keyword(s):  
Groundwater Flow ◽  
Numerical Models ◽  
Mining Waste ◽  
Mineral Weathering ◽  
Water Circulation ◽  
Open Pit ◽  
Hard Coal ◽  
Storage Site ◽  
Groundwater Flow Modelling ◽  
The Impact

An appropriate method of depositing post-mining waste can impede very significantly the water flow within the landfill and be one of the most effective methods of limiting the leaching of pollutants and their migration to the aquifer. The forecasting of water circulation and the dynamics of the process of pollutants leaching and their migration is supported by numerical modelling programs that allow assessing real conditions to follow changes in the processes over time. In case of reclamation of an open pit with post-mining wastes from hard coal mines, model research for the assessment of its impact on the aquatic environment should be supported by a complex of modern, uniform and mutually complementary methods of testing rock materials. The numerical models of groundwater flow and migration of pollutants required, among others, data on hydrogeological properties of rocks deposited in a storage site. They are based on both the results of field and laboratory tests. An important element in forecasting the impact of post-mining waste used in the reclamation of an open pit on groundwater is the quantitative assessment of the absorptive capacity of deposited wastes (mainly Carboniferous rocks) and the volume of free spaces of rock debris as a zone particularly susceptible to mineral weathering and pollution leaching. These tests must be carried out simultaneously with the simulation, in the laboratory, of changes in the filtration coefficient of loose materials depending on the thickness of the dump and changes in the vertical pressure exerted by rocks filled up during reclamation. Based on the example of research conducted on the material stored in the excavation after exploitation of backfilling sand, the authors proposed to adapt the research methods originally developed for the purposes of forecasting water hazards in mine shafts and underground excavations for the need of assessing changes in water circulation conditions within the dump.

Groundwater Flow Models in Open Pit Mining: Can We Do Better?

2014 ◽  
Vol 33 (2) ◽  
pp. 187-190 ◽  
Author(s):  
Keith Brown ◽  
Shane Trott
Keyword(s):  
Groundwater Flow ◽  
Open Pit ◽  
Open Pit Mining ◽  
Flow Models

Hydrogeology and Simulation of Groundwater Flow in the Plymouth-Carver-Kingston-Duxbury Aquifer System, Southeastern Massachusetts

2009 ◽  
Author(s):  
John P. Masterson ◽  
Carl S. Carlson ◽  
Donald A. Walter ◽  
Gardner C. Other contributing authors: Bent ◽  
Andrew J. Massey
Keyword(s):  
Groundwater Flow ◽  
Aquifer System
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