On Inflow to a Tunnel in a Fractured Double-Porosity Aquifer     

Mohammad M. Sedghi  Hongbin Zhan 《Ground water》2021,59(4):562-570

Inflow to a tunnel is a great public concern and is closely related to groundwater hydrology, geotechnical engineering, and mining engineering, among other disciplines. Rapid computation of inflow to a tunnel provides a timely means for quickly assessing the inflow discharge, thus is critical for safe operation of tunnels. Dewatering of tunnels is another engineering practice that should be planned. In this study, an analytical solution of the inflow to a tunnel in a fractured unconfined aquifer is obtained. The solution takes into account either the spherical or slab-shaped matrix block and the unsteady state interporosity flow. The instantaneous drainage water table and anisotropic hydraulic conductivities of the fractures network are also considered. Both uniform flux and uniform head boundary condition are considered to simulate the constant head boundary condition in the tunnel. The effects of the hydraulic parameters of the fractured aquifer on the inflow variation of the tunnel are explored. The application of the presented solution to obtain the optimum location and discharge of the well to minimize the inflow to a tunnel is illustrated.  相似文献   

Geostatistical Algorithm Selection for Mineral Resources Assessment and its Impact on Open-pit Production Planning Considering Metal Grade Boundary Effect     

Maleki  Mohammad  Madani  Nasser  Jélvez  Enrique 《Natural Resources Research》2021,30(6):4079-4094

Mine planning is influenced by many sources of uncertainty. Significant sources of geological uncertainty in mine planning include uncertainty in layout of geological domains and uncertainty in metal grades. These two sources of uncertainty cannot be modeled separately because the distribution of the grade is controlled usually by geological domains. Two approaches exist for combining these two sources of uncertainty: the joint simulation approach and the cascade approach. In this paper, these two approaches were compared using a real case study. To this end, uncertainty in iron grade (quantitative variable) and ore zones (qualitative variable) was modeled using both approaches. There were some considerable differences in the results obtained by each approach, which confirm the importance of choosing the most appropriate approach with consideration of the dominate features of a deposit.

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Experimental Investigation of Wettability Alteration from Water-wet to Oil-wet During Oil Migration     

Gholinezhadateni  Mohammad  Rostami  Behzad 《Natural Resources Research》2021,30(5):3735-3746

Natural Resources Research - Most oil reservoirs are first saturated with water and become oil-wet gradually due to oil migration and accumulation. Previous studies reported that the adsorption of...  相似文献   

A Novel Multiple-Kernel Support Vector Regression Algorithm for Estimation of Water Quality Parameters     

Najafzadeh  Mohammad  Niazmardi  Saeid 《Natural Resources Research》2021,30(5):3761-3775

Natural Resources Research - The quality of surface waters plays a key role in the sustainability of ecological systems. Measuring water quality parameters (WQPs) is of high...  相似文献   

Modulating the Impacts of Stochastic Uncertainties Linked to Deposit Locations in Data-Driven Predictive Mapping of Mineral Prospectivity     

Parsa  Mohammad  Carranza  Emmanuel John M. 《Natural Resources Research》2021,30(5):3081-3097

Natural Resources Research - The operation of large-scale ore-forming processes triggers the development of neighboring mineral deposits of the same or related types in a metallogenic province....  相似文献   

Modeling and assessing the effects of land use changes on runoff generation with the CLUE-s and WetSpa models     

Mohammady  Majid  Moradi  Hamid Reza  Zeinivand  Hossein  Temme  A.J.A.M.  Yazdani  Mohammad Reza  Pourghasemi  Hamid Reza 《Theoretical and Applied Climatology》2018,133(1-2):459-471

Theoretical and Applied Climatology - Land use change is an important determinant of hydrological processes and is known to affect hydrological parameters such as runoff volume, flood frequency,...  相似文献   

Enhancement and Mapping of Weak Multivariate Stream Sediment Geochemical Anomalies in Ahar Area,NW Iran     

Mohammad Parsa  Abbas Maghsoudi  Emmanuel John M. Carranza  Mahyar Yousefi 《Natural Resources Research》2017,26(4):443-455

In this study, stream sediment geochemical data have been subjected to robust principal components analysis (RPCA) and singularity mapping (SM) to enhance and map significant multivariate geochemical anomalies (i.e., mineralization-related) in Ahar area, NW Iran. The RPCA was applied to (a) account for the compositional nature of stream sediment geochemical data using suitable log-ratio transformation, (b) modulate the effect of outliers in component estimation and (c) derive a multivariate geochemical footprint of mineralization. The SM was applied to extract anomalous patterns of the multivariate geochemical footprint of mineralization. The exploration targets were then delineated using Student’s t-statistics analysis. The correlations of mapped exploration targets with the known mineral occurrences and mineralization-related patterns were further evaluated using normalized density index and overall accuracy analyses.  相似文献   

Statistical analysis of short-term water stress conditions at Riggs Creek OzFlux tower site     

Azmi  Mohammad  Rüdiger  Christoph  Walker  Jeffrey P. 《Theoretical and Applied Climatology》2017,130(1-2):497-509

Theoretical and Applied Climatology - A large range of indices and proxies are available to describe the water stress conditions of an area subject to different applications, which have varying...  相似文献   

Bringing globalization to the countryside: Special Economic Zones in India          下载免费PDF全文

Mohammad Amir Anwar  Pádraig Carmody 《Singapore journal of tropical geography》2016,37(2):121-138

Special Economic Zones (SEZs) are important vectors of neoliberal globalization in India. Despite facing widespread resistance against the proposed land acquisition for these zones, they are still being promoted across the country. We argue that the wealth redistribution to the country's elites and the fractured resistance movements enable neoliberalism and its practices to grow in the countryside. Using a private sector SEZ in Gurgaon as a case study, this article explores how special economic zoning, as a neoliberal policy, has been implicated in the spatialized production of poverty. We also show that the main actors who promote neoliberalism in India (the state and the large‐scale urban private sector) have found a seemingly unlikely ally in rural India in the form of farmers with large landholdings, rural elites who are willing to let go of their land under certain conditions. The data for the article was collected in India in 2009–10.  相似文献   

Spatial correlation for horizontal and vertical components of acceleration from northern Iran seismic events     

Alireza Garakaninezhad  Morteza Bastami  Mohammad Reza Soghrat 《Journal of Seismology》2017,21(6):1505-1516

The evaluation of seismic risk of spatially distributed systems requires the spatial correlation model for ground motion intensity measures. This study investigates the spatial correlation of four earthquakes recorded in northern Iran. The intra-event spatial correlation for both horizontal and vertical components of spectral acceleration at eight periods in the range of 0.0–3.0 s is estimated using geostatistical tools. An exponential form is chosen to fit experimental semivariograms, and the correlation ranges of spectral accelerations as a function of period are derived. The results show similar trend of correlation ranges for both components. It should be mentioned that the ranges for the vertical component, in general, are higher than those observed for the horizontal one. For both components, the correlation ranges as a function of period are divided into three segments. The first and the third one are increasing while the second one is decreasing with increasing period.  相似文献