Simulating Head Recovery and Intermittent Discharge in Free Flowing Wells          下载免费PDF全文

Ferenc Székely 《Ground water》2017,55(6):879-884

Modeling of the head recovery (buildup) in and intermittent operation of flowing wells lacks rigorous analytical tools. Presently different methods are applied in discharging and recovery phases. The presented reliable approximate solution considers a continuous free flow process and time variant screen loss parameters. The latter are temporarily set to large value to prevent inflow into the well bore during the single recovery or in repeated shut down periods. This method is called as screen loss control or SLC technique and is verified by means of comparative analysis with the constant rate pumping‐recovery test simulated in leaky aquifer. The evaluation of the free flow and recovery test in the free flowing well 28 (Artesia Heights) concluded with calibrated parameters close to those obtained in the earlier analyses based on split well flow process. The simulation of intermittent flowing well operation also underwent successful validation resulting in reasonable values of the Q_w and s response functions.  相似文献   

Geoelectric Characterization of Thermal Water Aquifers Using 2.5D Inversion of VES Measurements     

Á. Gyulai  P. Szűcs  E. Turai  M. K. Baracza  Z. Fejes 《Surveys in Geophysics》2017,38(2):503-526

This paper presents a short theoretical summary of the series expansion-based 2.5D combined geoelectric weighted inversion (CGWI) method and highlights the advantageous way with which the number of unknowns can be decreased due to the simultaneous characteristic of this inversion. 2.5D CGWI is an approximate inversion method for the determination of 3D structures, which uses the joint 2D forward modeling of dip and strike direction data. In the inversion procedure, the Steiner’s most frequent value method is applied to the automatic separation of dip and strike direction data and outliers. The workflow of inversion and its practical application are presented in the study. For conventional vertical electrical sounding (VES) measurements, this method can determine the parameters of complex structures more accurately than the single inversion method. Field data show that the 2.5D CGWI which was developed can determine the optimal location for drilling an exploratory thermal water prospecting well. The novelty of this research is that the measured VES data in dip and strike direction are jointly inverted by the 2.5D CGWI method.  相似文献   

Influence of IHSS Standard and Reference Materials on Copper and Mercury Toxicity to Vibrio fischeri     

James J. Alberts  Monika Takcs  Mala Pattanayek 《洁净——土壤、空气、水》2001,28(7):428-435

The reduction in light emission of the marine bacterium Vibrio fischeri used in the standard Microtox^® bioassay was measured for the metals copper and mercury. The concentration at which the light emission was reduced by 50% (EC₅₀) was determined to be (3.43 ± 0.83) μmol/L for Cu²⁺ and (0.66 ± 0.01) μmol/L for Hg²⁺. The reduction of the toxicity of these metals by humic and fulvic acids were studied using IHSS Standard and Reference Materials. Copper toxicity was reduced 17...20% by the soil and peat fulvic acids and 9...20% by the aquatic fulvic acids. While there appeared to be little difference in the reduction of Cu toxicity by fulvic acids from soils, peats, or aquatic systems, Hg toxicity was reduced 3.6...7.3% by the soils and peats, while aquatic fulvic acids reduced Hg toxicity 14...16%. Soil fulvic acids appear to have significantly less capacity to reduce Hg toxicity than Cu toxicity. Humic acids had much higher reductions of Cu toxicity (44...124%) compared to the fulvic acids, with little difference between aquatic and soil or peat humic acids, 44...124% and 67...100%, respectively. However, humic and fulvic acids, regardless of origin, had approximately the same effect on Hg toxicity with 3.5...16% reduction by fulvic acids and 8...20% reduction by humic acids. Unlike the fulvic acids, no clear trend was observed relative to origin of the humic acids. There was no correlation between percent reduction of Cu or Hg toxicity by the organic compounds and copper binding capacity (CuBC), C/N ratio, or carboxyl content of the materials. Examination of natural organic matter (NOM) isolated by reverse osmosis techniques from three water sources had reductions of both Cu and Hg toxicity that were most similar to the Suwannee River and Nordic fulvic acids.  相似文献   

Economic Development and Emission Control over the Long Term: The ICLIPS Aggregated Economic Model     

Marian Leimbach  Ferenc L. Toth 《Climatic change》2003,56(1-2):139-165

In integrated assessments of climate change, greenhouse-gasemissions and climate change impacts provide the linkages betweenthe world economy and the climate system. Key climatic processesoperate at the scales of centuries. This requires highlyaggregated models for portraying the dynamics of the economicsystem. An extended Ramsey-type optimal growth model is presentedas the appropriate tool to be integrated with a reduced-formclimate model in the ICLIPS integrated assessment. Theeleven-region model of the world economy involves exogenouspopulation and endogenous investment dynamics with productivityprogress based on a technological diffusion model. World regionsare linked via intertemporal trade flows of the compositeconsumption/investment good, capital mobility, and emission permittrading. Coupled with the ICLIPS Climate Model, the AggregatedEconomic Model can determine corridors of permitted long-termcarbon emission paths or, as primarily discussed in this paper,specific cost-effective emission trajectories. The sensitivity ofmitigation costs to externally specified climate change/impactconstraints and to assumptions about non-CO₂ greenhouse-gasemissions is also discussed.  相似文献   

Using visibility analysis to improve point density and processing time of SfM-MVS techniques for 3D reconstruction of landforms     

Álvaro Gómez-Gutiérrez  Trent Biggs  Napoleon Gudino-Elizondo  Paz Errea  Esteban Alonso-González  Estela Nadal Romero  José Juan de Sanjosé Blasco 《地球表面变化过程与地形》2020,45(11):2524-2539

Image network geometry, including the number and orientation of images, impacts the error, coverage, and processing time of 3D terrain mapping performed using structure-from-motion and multiview-stereo (SfM-MVS). Few studies have quantified trade-offs in error and processing time or ways to optimize image acquisition in diverse topographic conditions. Here, we determine suitable camera locations for image acquisition by minimizing the occlusion produced by topography. Viewshed analysis is used to select the suitable images, which requires a preliminary digital elevation model (DEM), potential camera locations, and sensor parameters. One aerial and two ground-based image collections were used to analyse differences between SfM-MVS models produced using: (1) all available images (ALL); (2) images selected using conventional methods (CON); and (3) images selected using the viewshed analysis (VIEW). The resulting models were compared with benchmark point clouds acquired by a terrestrial laser scanner (TLS) and TLS-derived DEMs. The VIEW datasets produced denser point clouds (28–32% more points) and DEMs with up to 66% reduction in error compared with CON datasets due to reduction of gaps in the DEM. VIEW datasets reduced processing time by 37–76% compared with ALL, with no reduction in coverage or increase in error. DEMs produced with ALL and VIEW datasets had similar slope and roughness, while slight differences that may be locally important were observed for the CON dataset. The new method helps optimize SfM-MVS image collection strategies that significantly reduce the number of images required with minimal loss in coverage or accuracy over complex surfaces. © 2020 John Wiley & Sons, Ltd.  相似文献   

Leaky Aquifer Models to Simulate the Well Flow in Fractured Aquifers with Linear Interporosity Flow     

Ferenc Székely  Péter Szűcs  Balázs Zákányi 《Ground water》2019,57(5):687-692

Following Hemker and Maas (1987) the models of two or three leaky aquifers are applied to simulate the flow to vertical wells operating in the fractured or dual porosity aquifers. The software WellTest (WT) (Székely 2015) is used for calculating the drawdown and discharge rate variation. The comparative analysis with the independent analytical solutions by Boulton and Streltsova-Adams (1978), Warren and Root (1963), Kazemi et al. (1969) concluded with acceptable agreement between the WT simulation and the alternate calculation methods. The selected field tests have been conducted in fractured limestone aquifers. The pumping test west of Copenhagen shows an example of fractured aquifer with considerable negative skin effect at the well face. The flowing well Wafra W1 in Kuwait operates in the two-zone aquifer exhibiting sufficient vertical recharge via leakage beyond a circular domain of estimated radius of 2460 m.  相似文献   

Identification of Bedrock Lithology using Fractal Dimensions of Drainage Networks extracted from Medium Resolution LiDAR Digital Terrain Models     

Joaquín Cámara  Vicente Gómez-Miguel  Miguel Ángel Martín 《Pure and Applied Geophysics》2016,173(3):945-961

  相似文献   

Fire severity and surface rock fragments cause patchy distribution of soil water repellency and infiltration rates after burning   总被引：3，自引：0，他引：3       下载免费PDF全文

Ángel J. Gordillo‐Rivero  Jorge García‐Moreno  Antonio Jordán  Lorena M. Zavala  Fernando M. Granja‐Martins 《水文研究》2014,28(24):5832-5843

Although fire‐induced soil water repellency (SWR) and its effects on soil hydrology and geomorphology have been studied in detail, very few studies have considered the effect of rock fragments resting on the soil surface or partly embedded in soil. In this research, we have studied the effect of rock fragments on the strength and spatial distribution of fire‐induced SWR at different fire severities. A fire‐affected area was selected for this experiment and classified into different zones according to fire severity (unburned, low, moderate and high) and rock fragment cover (low, <20% and high, >60%). During 7 days after fire, SWR and infiltration rates were assessed in the soil surface covered by individual rock fragments and in the midpoint between two adjacent rock fragments (with maximum spacing of 20 cm). SWR increased with fire severity. Rock fragments resting on the soil surface increased the heterogeneity of the spatial distribution of fire‐induced SWR. SWR increased significantly with rock fragment cover in bare areas under moderate and high fire severity, but quantitatively important changes were only observed under high fire severity. In areas with a low rock fragment cover, water repellency from soil surfaces covered by rock fragments increased relative to bare soil surfaces, with increasing SWR. In areas with a high rock fragment cover, SWR increased significantly from non‐covered to covered soil surfaces only after low‐severity burning. Rock fragment cover did not affect infiltration rates, although it decreased significantly in soil surfaces after high‐severity burning in areas under low and high rock fragment cover. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Performance of buildings with masonry infill walls during the 2011 Lorca earthquake   总被引：1，自引：1，他引：0  

Lutz Hermanns  Alberto Fraile  Enrique Alarcón  Ramón Álvarez 《Bulletin of Earthquake Engineering》2014,12(5):1977-1997

On Wednesday 11th May 2011 at 6:47 pm (local time) a magnitude 5.1 Mw earthquake occurred 6 km northeast of Lorca with a depth of around 5 km. As a consequence of the shallow depth and the small epicentral distance, important damage was produced in several masonry constructions and even led to the collapse of one of them. Pieces of the facades of several buildings fell down onto the sidewalk, being one of the reasons for the killing of a total of 9 people. The objective of this paper is to describe and analyze the failure patterns observed in reinforced concrete frame buildings with masonry infill walls ranging from 3 to 8 floors in height. Structural as well as non-structural masonry walls suffered important damage that led to redistributions of forces causing in some cases the failure of columns. The importance of the interaction between the structural frames and the infill panels is analyzed by means of non-linear Finite Element Models. The resulting load levels are compared with the member capacities and the changes of the mechanical properties during the seismic event are described and discussed. In the light of the results obtained the observed failure patterns are explained. Some comments are stated concerning the adequacy of the numerical models that are usually used during the design phase for the seismic analysis.  相似文献   

Tectonic setting of the recent damaging seismic series in the Southeastern Betic Cordillera,Spain     

Emilio Rodríguez-Escudero  José J. Martínez-Díaz  José A. Álvarez-Gómez  Juan M. Insua-Arévalo  Ramón Capote del Villar 《Bulletin of Earthquake Engineering》2014,12(5):1831-1854

In this work we analyze the tectonic setting of the recent damaging seismic series occurred in the Internal Zones of the eastern Betic Cordillera (SE Spain) and surrounding areas, the tectonic region where took place the 11th May 2011 Mw 5.2 Lorca earthquake. We revisit and make a synthesis of the seven largest and damaging seismic series occurred from 1984 to 2011. We analyze their seismotectonic setting, and their geological sources under the light of recent advances in the knowledge on active faults, neotectonics, seismotectonics and stress regime, with special attention focused on the Lorca Earthquake. These seismic series are characterized by two types of focal mechanisms, produced mainly by two sets of active faults, NNW–SSE to NNE–SSW small (no larger than 20–30 km) extensional faults with some strike slip component, and E–W to NE–SW large strike slip faults (more than 50 km long) with some compressional component (oblique slip faults). The normal fault earthquakes related to the smaller faults are dominant in the interior of large crustal tectonic blocks that are bounded by the large E–W to NE–SW strike-slip faults. The strike slip earthquakes are associated to the reactivation of segments or intersegment regions of the large E–W to NE–SW faults bounding those crustal tectonic blocks. Most of the seismic series studied in this work can be interpreted as part of the background seismicity that occurs within the crustal blocks that are strained under a transpressional regime driven by the major strike slip shear corridors bounding the blocks. The seismotectonic analysis and the phenomenology of the studied series indicate that it is usual the occurrence of damaging compound earthquakes of M  \(\sim \)  5.0 associated with triggering processes driven by coseismic stress transfer. These processes mainly occur in the seismic series generated by NNW–SSE to NNE–SSW faults. These mechanical interaction processes may induce a higher frequency of occurrence of this kind of earthquakes than considered in traditional probabilistic seismic hazard assessments and it should be taken into account in future seismic hazard assessments.  相似文献