Understanding and managing the stressed Mexico-USA transboundary Hueco bolson aquifer in the El Paso del Norte region as a complex system     

Zhuping Sheng  Jeff Devere 《Hydrogeology Journal》2005,13(5-6):813-825

As the latest drought has swept over the southwestern United States, most local and regional water providers have had to rely on ground water to meet their water demands as surface water supplies have diminished. In areas near major population centers this situation has continued to put strain and stress on already over-drafted regional aquifers. Metropolitan centers throughout the southwestern United States, as exemplified by Las Vegas, Nevada; Phoenix and Tucson, Arizona; and El Paso, Texas, have a history of over drafting their available ground water resources. How these stressed aquifers should be managed is an urgent issue. In El Paso, Texas long-term groundwater mining in the transboundary Hueco bolson aquifer has resulted in large water level drawdowns within the basin, particularly in several well fields. This situation has promoted the intrusion of brackish water into fresh water zones, and consequently reduced the volume of fresh water stored in the aquifer. Management of this aquifer is made more complex as the water resources of the region are shared across the United States/Mexico boundary and the transboundary region continues to grow rapidly. This paper describes the current situation within the Hueco bolson due to over drafting and continued reliance on the fresh water in storage and describes how understanding the dynamics of the aquifer as a complex system can offer managerial perspectives that can be used to establish operational procedures and programs for bringing drawdowns into equilibrium, increasing the longevity of the aquifer, gradually restoring water quality, and offering the hope of utilization of the resource in a sustainable manner.

---

Resumen A medida que la última sequía ha pasado ligeramente sobre el suroeste de Estados Unidos la mayoría de abastecedores locales y regionales de agua han tenido que depender del agua subterránea para satisfacer sus demandas de agua debido a que las fuentes de agua superficial han disminuido. En áreas cerca de centros poblados principales esta situación ha continuado ejerciendo presión en los ya sobre explotados acuíferos regionales. Los centros metropolitanos en todo el suroeste de Estados Unidos, por ejemplo Las Vegas, Nevada; Fénix y Tucson, Arizona; y El Paso, Texas tienen una historia de sobre explotar los recursos de agua subterránea disponibles.La gestión de estos acuíferos estresados constituye un problema urgente. En El Paso, Texas el minado de agua subterránea a largo plazo en el acuífero transnacional Hueco bolsón ha resultado en varios campos de pozos. Esta situación ha promovido la intrusión de agua salobre hacia zonas con agua fresca y reducido consecuentemente el volumen de agua fresca almacenado en el acuífero. El manejo de este acuífero se hace más complejo debido a que los recursos hídricos de la región son compartidos a través del límite Estados Unidos/México y la región transnacional continúa creciendo rápidamente. Este artículo describe la situación actual dentro del Hueco bolsón debido a la sobre explotación y continua dependencia en el agua fresca almacenada y describe como el entendimiento de la dinámica del acuífero como un sistema complejo puede ofrecer perspectivas de gestión que pueden utilizarse para establecer procedimientos operacionales y programas que conduzcan al equilibrio de los descensos, aumentando la longevidad del acuífero, gradualmente restaurando la calidad del agua, y ofreciendo la esperanza de utilizar el recurso de manera sostenible.

---

Résumé Alors que la dernière sécheresse a atteint toute la partie Sud-Ouest des Etats-Unis, la plus part des distributeurs deau, locaux et régionaux, doivent sapprovisionner en eau souterraine dés lors que les niveaux des eaux de surface ont diminués. Dans les zones proches des grands centres densément peuplés, cette situation a continuée a altérée des aquifères déjà surexploités. Les centres métropolitains du Sud-Ouest des Etats-Unis (Las Vegas dans le Nevada, Phoenix et Tucson dans lArizona, El Paso au Texas) sont connus historiquement pour surexploités leurs ressources en eaux souterraines. Il devient urgent de définir un mode de gestion de ses aquifères surexploités. A El Paso dans le Texas, le minage de laquifère transfrontalier engendre un rabattement important dans le bassin, et plus particulièrement autour des zones de captage. Cette situation a induit lintrusion deaux saumâtres dans des zones deaux douces, et a par conséquent réduit le volume deau douce stockée et exploitable dans laquifère. La gestion de cet aquifère est par ailleurs complexifiée par la situation transfrontalière, dautant que la zone frontalière connaît une croissance rapide. Cet article décrit la situation actuelle dans la vallée fermée du Hueco, due au sur-rabattement et à lexploitation continue des eaux douces, et décrit comment la compréhension de laquifère, vu comme un système complexe, peut offrir des perspectives de gestion amenant à des procédures opérationnelles et à des programmes à long terme permettant de ramener à léquilibre la baisse des niveaux deau. Ainsi la longévité de laquifère sera mieux garantie, la qualité de leau sera graduellement restaurée et lutilisation de leau respectera le souci de développement durable.

  相似文献   

The Local Magnitude Scale in the Korean Peninsula     

Sung Kyun?KimEmail author  Min Ah?Park 《Pure and Applied Geophysics》2005,162(5):875-889

A formula to determine the local magnitude (M_L) following Richters original definition was empirically derived for the Korean Peninsula. A total of 1,644 digital seismograms from 142 Korean earthquakes that occurred from 1997 to 2000 were corrected for instrument response and convolved with the nominal Wood-Anderson torsion seismograph response to be appropriate for the original definition of M_L. Then, the zero-to-peak amplitude was measured in millimeters on the synthetic Wood-Anderson seismogram. Multiple regression analysis was conducted to determine distance and station correction terms for the measured peak amplitudes. The best-fit solution for M_L yielded the following formula for the Korean Peninsula:where A() and S denote the peak amplitude on the synthetic Wood-Anderson seismogram at distance and the station correction term, respectively. Note that the second term, distance correction, was adjusted with Richters M_L, taking into consideration attenuation differences between the Korean Peninsula and southern California, where Richter originally introduced M_L. On average, the magnitudes determined in this study are nearly the same as those determined by the Korea Institute of Geoscience and Mineral Resources (KIGAM), but are larger than those of the Korea Meteorological Administration (KMA) by as much as 0.36.  相似文献   

Interplay between shoreline migration paths, architecture and pinchout distance for siliciclastic shoreline tongues: evidence from the rock record     

TORE M. LØSETH  RON J. STEEL†  JEFF P. CRABAUGH‡  MAIJA SCHELLPEPER‡ 《Sedimentology》2006,53(4):735-767

Facies, geometry and key internal stratigraphic surfaces from eight Cretaceous and Eocene clastic shoreline tongues have been documented. The regressive parts of all the studied tongues represent storm‐wave influenced strandplains, deltas or fan‐deltas, and the regressive shoreline trajectories varied from descending to ascending. The transgressive parts of the tongues are dominated by either estuarine or coastal‐plain deposits. The distance from the coeval, up‐dip non‐marine deposits to the basinward pinchout of amalgamated shoreface sandstones, measured along depositional dip, is here termed the sand pinchout distance. The study shows that the angle of regressive‐to‐transgressive turnaround (defined by the angle between the regressive and subsequent transgressive shoreline trajectories) and the process regime during turnaround largely control the sand‐pinchout distance. The amount of transgressive erosion can also partly control the pinchout distance, but this parameter was comparable for the different examples presented here. If the type of depositional system at turnaround and the depth of transgressive erosion are constant, small angles of turnaround are associated with large pinchout distances, whereas larger angles of turnaround result in smaller pinchout distances. The model developed allows sand‐pinchout distance to be predicted, using data for the landward parts of shoreline tongues. The dataset also shows that steeply rising (aggrading) shoreline trajectories tend to produce more heterolithic sandstone tongues than those formed by lower‐angle trajectories.  相似文献   

Classical Cepheids and the Distances of HST Program Galaxies     

H. V. Abrahamyan 《Astrophysics》2004,47(3):389-403

The distances of HST program galaxies are revised using the PL-relations we have obtained previously along with a different method from that employed by Freedman et al. On the average, the resulting distances to these galaxies have higher internal accuracies than those obtained before by others. In addition, we have used no corrections for metallicity or for the incompleteness of the samples of classical cepheids in deriving these distances. Despite this, our distance moduli, with a dispersion of ±0^m.395, agree with those of Freedman et al. This indicates that these two effects have little or even no effect for the samples of classical cepheids in the HST program galaxies.  相似文献   

Influence of precambrian basement on the chemical composition of Mesozoic granitoid rocks in northeastern Asia     

M. A. Romanova 《Mathematical Geology》1991,23(7):959-979

A hypothesis for effects of stable tectonic elements on chemical composition of Mesozoic granitoids in northeastern Asia is tested. Chemical compositional change of granitoid rocks is examined in nine-dimensional space of rock-forming oxides. Stable geologic structures of the region are outlined by trends of Euclidean distances between rock recognized as a standard in a space of major rock-forming oxides and composition of individual samples. A data-smoothing polynomial of the fourth order corresponds closely to the geology of the region. Chemically stable masses of quartz diorite are thought to be delivered directly from magmatic sources along deep faults. A great variety of acidic granites, which occupy for each analysis separate cells in the nine-dimensional classification, are presumed to be palingenetic in origin.  相似文献   

The radio emission from Sakurai's Object (beyond 1 mm)     

S.P.S. Eyres 《Astrophysics and Space Science》2002,279(1-2):69-75

Observations of V4334 Sgr have been made with the JCMT, MERLIN, ATCAand the VLA. Searches with JCMT for CO in and around the PNassociated with V4334 Sgr has provided upper limits for the peakemission of 20 mK and the line-flux of 0.17 K-km s^-1. Thisgives an upper limit on the CO mass of 3 × 10^-7D² M at D kpc. VLA observations havedetected 2.7 ± 0.1 mJy of emission from the PN, which appears to beclumpy and extends to a radius of 17 arcsec. This indicates anoptically thick nebula, and suggests a range of distances of 1.83 to4.96 kpc for a reasonable range of masses for optically thick PN.Comparison with estimated total H emission gives E(B-V) =0.8 ±0.1. MERLIN observations do not detect the wind indicated tobe present in IR observations prior to dust obscuration. TheAustralia Telescope Compact Array did not detect OH maser emissionfrom either the main- or satellite-lines. Future VLA observationswill increase integration times and uv-coverage to significantlyimprove the radio imaging. MERLIN target-of-opportunity time isretained in order to attempt to image any fast wind as it develops.An independent estimate of the PN mass would allow the use of theradio observations to determine the distance; conversely anindependent distance measurement would lead to a PN mass estimate.The author urges the acquisition of an accurate measurement of thetotal H emission from the PN.  相似文献   

“03.8”辽宁地区暴雨过程成因的诊断分析   总被引：3，自引：0，他引：3  

王健  寿绍文  陈力强  何玉科 《气象》2005,31(4):18-22

对2003年8月5～6日辽宁地区暴雨过程的环流形势及雷达回波进行了分析。并利用中尺度MM5模式对这次暴雨过程的模拟结果进行了诊断分析，探讨了过程中主要影响系统——华北气旋在渤海西岸生成后迅速发展加强的原因。结果表明。中纬度短波槽的充分发展引导贝加尔湖冷空气的南下、副高的稳定与加强和低空急流的建立输送大量暖湿气流是华北气旋生成的重要条件。而“干侵入”则是造成此次华北气旋迅速发展加强的重要原因。  相似文献   

三角高程测量中天顶和斜距的计算   总被引：1，自引：0，他引：1  

王培洲 《四川测绘》2000,23(2):87-89

本文通过分析大气密度与大气垂直折光系数的关系 ,推导出消除了大气垂直折光影响的天顶距和斜距计算公式 ,既拓宽了天顶距的适用范围 ,又提高了三角高程测量成果精度。  相似文献   

光电测深和激光投点技术在矿井联系测量中的试验研究     

徐乃忠  侯公羽  朱广斌  王玉君  蒋正钦 《测绘工程》2000,9(3):41-43

介绍了光电测距仪直接在井筒中测定井深导入高程和激光投点代替钢丝投点的试验研究,并和传统方法进行比较,结果令人十分满意。  相似文献   

    

Yu Xing  Dai Jin  Jiang Weimei  Fan Peng 《大气科学进展》2000,17(4):617-635

It is essential to learn the temporal and spatial concentration distributions and variations of seeding agents in cloud seeding of precipitation enhancement. A three–dimensional puff trajectory model incorporating a mesoscale nonhydrostatic model has been formulated, and is applied to simulating the transporting and diffusive characteristics of multiple line sources of seeding agents within super–cooled stratus. Several important factors are taken into consideration that affect the diffusion of seeding materials such as effects of topography and vertical wind shear, temporal and spatial variation of seeding parameters and wet deposition. The particles of seeding agents are assumed to be almost inert, they have no interaction with the particles of the cloud or precipitation except that they are washed out by precipitation. The model validity is demonstrated by the analyses and comparisons of model results, and checked by the sensitivity experiments of diffusive coefficients and atmospheric stratification. The advantage of this model includes not only its exact reflection of heterogeneity and unsteadiness of background fields, but also its good simulation of transport and diffusion of multiple line sources. The horizontal diffusion rate and the horizontal transport distance have been proposed that they usually were difficult to obtain in other models. In this simulation the horizontal diffusion rate is 0.82 m s⁻¹ for average of one hour, and the horizontal average transport distance reaches 65 km after 1 h, which are closely related to the background fields.  相似文献