Influence of Saturated Wedge Hydrodynamics on Hillslope-Stream Connectivity

More and more research is being conducted to investigate the water flowpaths in a watershed from the time water falls as precipitation to the time it becomes streamflow. Understanding the flow of water in the subsurface is a prerequisite to understanding the quality and quantity of water in streams because subsurface pathways define the earth materials that waters will come in contact with, and these pathways set transit times, which dictate the time available for chemical reactions (Anderson et al., 1997). Recent research has identified the need to combine hydrometric and chemical (tracer) studies to advance the understanding of watershed flow mechanisms (Freer et al., 2002, Joerin et al., 2005, and McDonnell et al., 1999). The research presented provides actual hydrometric and artificial tracer data to test the hydrological connectivity hypothesis proposed by McNamara et al. (2005). This goal was achieved by addressing two main objectives: 1) testing the growth of the saturation wedge in and around the near-stream zone, and 2) testing if, and when, the hillslope becomes hydrologically connected to the stream. These objectives were accomplished by analyzing hydrometric and geochemical field data to describe the vertical and lateral flow evolution on the hillslopes and the crucial role that the saturated wedge plays in connecting the hillslopes to the stream. Hydrometric and geochemical data provide evidence of the hillslope connection to the stream via the saturated wedge. The connectivity of the hillslope to the stream is hinged on the soils reaching their specific retention moisture content during the wet spring high flux period. Once the specific retention is satisfied, lateral flow in the shallow soils commences, followed by deep soil-bedrock interface flow. Solute recharge in the stream is primarily due to bedrock flow and the saturated wedge development in the near-stream environment. The saturated wedge lateral extent is further extenuated by the presence of clay lenses in the hillslopes. Finally, data presented in this work indicates stream water and solute loss in the middle and lower portions of the watershed to the underlying fractured granite bedrock

The Fourth-Century Rediscovery of Christian Jerusalem

Despite Jerusalem\u27s obvious importance in early Christianity, as the site of the most important events of the faith, it wasn\u27t until the fourth century that the city truly became the center of Christianity. Indeed, it was the exciting events of that century, most notably the rediscovery of the sepulcher of Jesus, which elevated the city from an unimportant, even forgotten city of the Roman Empire to the Christian city par excellence. This thesis will survey Christianity\u27s humble beginnings in Jerusalem and the subsequent decline of both the city and the religion, and then will propose that a new Christian identity arose from the seedbed of its physical and geographical origins. From first century ruins to fourth century splendor, Jerusalem the city was reborn, and with this geographic rebirth - came a renewal of its faith

An Ion Mobility Spectrometer Sensor System for Subsurface Use

Ion mobility spectrometry (IMS), using stand-alone instrumentation and hyphenated with mass spectrometry (IM-MS), has recently undergone significant expansion in the numbers of users and applications, particularly in sectors outside its established user base; predominantly military and security applications. Although several IMS reference standards have been proposed, there are no currently universally recognised reference standards for the calibration and evaluation of mobility spectrometers. This review describes current practices and the literature on chemical standards for validating IMS systems in positive and negative ion modes. The key qualities and requirements an ‘ideal’ reference standard must possess are defined, together with the instrumental and environmental factors such as temperature, electric field, humidity and drift gas composition that may need to be considered. Important challenges that have yet to be resolved are also identified and proposals for future development presented

Geothermal Site Assessment Using the National Geothermal Data System (NGDS), with Examples from the Hawthorne Ammunition Depot Area

The Nevada Bureau of Mines and Geology and Great Basin Center for Geothermal Energy have compiled nearly 50,000 Great Basin groundwater samples into an Access database, encompassing all known spatial, physical, and geochemical features. The database schema is a partial template for the National Geothermal Data System (NGDS), a DOE-sponsored compendium of geothermal data spanning all 50 states. The database can be queried to produce worksheets customized to user requirements, greatly simplifying data extraction for other software applications (e.g., GoogleEarth). This paper examines the features and functionality of the existing database, its integration into the 50-state NGDS, and its usage in geothermal exploration and development. In particular, we examine the dataset for Hawthorne, NV, which has been supplemented extensively by the Naval Geothermal Program Office and subcontractor Epsilon Systems Solutions, Inc. As we demonstrate, a database user can identify Hawthorne-area thermal anomalies several ways: through spatial interpolation of database geothermometry, temperature gradient calculations, and other geochemical signatures. The ratios of B/Cl, Li/Cl, and As/Cl may identify zones of geothermal potential, as can regional patterns of total dissolved solids, Na-K-Ca ternary diagrams, and trace element ternary diagrams