The impact of groundwater and agricultural expansion on the archaeological sites at Luxor, Egypt

Pharaonic monuments represent the most valuable source of ancient Egypt, covering the period of approximately 3000-300 B.C. Karnak and Luxor temples represent the monuments of the east bank of Thebes, the old capital of Egypt. These monuments are currently threatened due to rising groundwater levels as a result of agricultural expansion after construction of the High Dam in the 1970s.Deterioration of archaeological sites at Luxor includes disintegration and exfoliation of stones, dissolution of building materials, loss of moral paintings, crystallization of salts in walls and columns, stone bleeding, destruction of wall paintings and texts, decreasing the durability of monumental stones, and discoloring.The hydrogeologic and climatic conditions combined with irrigation practices facilitated the weathering processes to take part in deterioration of archaeological sites at Luxor area. Many varieties of salt species are found in groundwater at the study area which react with country rocks including the archaeological foundations. These salts are not in equilibrium but in a dissolution and/or dissolution-precipitation phases which are responsible for the different types of deterioration features of Luxor and karnak temples including dissolution of the salts or minerals of the building stones and/or precipitation and crystallization of new salts. © 2014 Elsevier Ltd

Internet of Things in Water Management and Treatment

The goal of the water security IoT chapter is to present a comprehensive and integrated IoT based approach to environmental quality and monitoring by generating new knowledge and innovative approaches that focus on sustainable resource management. Mainly, this chapter focuses on IoT applications in wastewater and stormwater, and the human and environmental consequences of water contaminants and their treatment. The IoT applications using sensors for sewer and stormwater monitoring across networked landscapes, water quality assessment, treatment, and sustainable management are introduced. The studies of rate limitations in biophysical and geochemical processes that support the ecosystem services related to water quality are presented. The applications of IoT solutions based on these discoveries are also discussed

A QUANTITATIVE ANALYSIS OF HYDROTHERMAL CIRCULATION AROUND MID-OCEAN RIDGE MAGMA CHAMBERS.

Hydrothermal activity is one of the dominant processes affecting the chemical and thermal evolution of oceanic crust at the mid-ocean ridge (MOR), but little is known about the sub-surface portions of ridge hydrothermal systems. These systems can be investigated using numerical modeling techniques, and models of two-dimensional cross-sections are utilized in this study to investigate the behavior of MOR hydrothermal systems. The influence of magma chamber geometry is explored by modeling two extremes of proposed geometry. Seismological evidence supports a dike-like 2 km half-width chamber, and models of this chamber indicate that: (1) complete crystallization of the magma requires 30,000 years, (2) hydrothermal upflow and hot springs are concentrated in a narrow band within 1.5 km of the ridge axis for the lifetime of the system, (3) a large hydrothermal cell forms and remains centered above the distal tip of the intrusion for the lifetime of the system, (4) effective hydrothermal activity ends by 70,000 yrs. Petrological evidence supports a wide sill-like chamber 15 km in half-width, and models of this chamber indicate that: (1) complete crystallization of the magma requires 100,000 yrs, (2) hydrothermal vents are present at the ridge axis, but most of the vents are located 5-10 km away from the axis, (3) a large hydrothermal cell develops at the distal tip of the magma chamber, while a series of small but vigorous cells develops directly above the intrusion, both features migrate toward the ridge axis as the magma solidifies, (4) effective hydrothermal activity ends by 170,000 yrs. Substantially different hydrothermal systems develop around these two chamber geometries and comparison of the models shows this is because different patterns of near-critical P-T conditions developed around them. The fundamental influence on the nature and pattern of hydrothermal circulation at MOR is the distribution of near-critical conditions

Predicted fate of tritium residuum from groundwater tracer experiments in the Amargosa Desert, southern Nevada

Analytic solutions are used in this study to evaluate potential groundwater transport of tritium used in goundwater tracer tests southwest of the Nevada Test Site. Possible transport from this site is of interest because initial radionuclide concentrations were high and the site is close to goundwater discharge points (12 km). Anecdotal evidence indicates that 90 percent of these tracers were removed by pumping at the completion of the tests; this study examines the probable transport of the tracers with and without the removal. Classical dispersive transport analytic solutions are used, treating the tracer test as a point slug injection. Input parameters for the solutions were measured at the site, and consideration of parameter uncertainty is incorporated in the results. With removal of the tracer, the maximum expected region with above-Safe Drinking Water Act (40 CFR 121) concentrations of tritium extends 5 km from the injection point, and does not reach any sites of public access. Detectable tritium from the tests is likely to have reached the Ash Meadows fault zone, but flow along the fault probably diluted the tracer to below detection limits before arrival at springs along the fault. Arrival at the springs would have occurred 20 to 25 years after the tests. Without removal of the tracer, the solutions indicate that tritium concentrations just above Safe Drinking Water Act standards would have reached the Ash Meadows fault zone. In this case, detectable tritium might have been found in Devil`s Hole or Longstreet Spring, the nearest points of possible public exposure

Estimates of potential radionuclide migration at the Bullion site

The Bullion site in Area 20 of the Nevada Test Site has been selected for an intensive study of the hydrologic consequences of underground testing, including subsequent radionuclide migration. The bulk of the chimney and cavity lie in zeolitized tuffs of low hydraulic conductivity, while the base of the cavity may extend downward into more conductive rhyolite flows. A mathematical analog to the Bullion setting is used here to estimate expected radionuclide migration rates and concentrations. Because of a lack of hydrologic data at the site, two contrasting scenarios are considered. The first is downward-transport, in which downward hydraulic gradients flush chimney contents into the conductive underlying units, enhancing migration. The other is upward-transport, in which upward gradients tend to drive chimney contents into the low-conductivity zeolitized tuffs, discouraging migration. In the downward-transport scenario, radionuclide travel times and concentrations are predicted to be similar to those encountered at Cheshire, requiring approximately 10 years to reach a proposed well 300 m downgradient. The upward transport scenario yields predicted travel times on the order of 2,000 years to the downgradient well. The most likely scenario is a combination of these results, with vertical movement playing a limited role. Radionuclides injected directly into the rhyolites should migrate laterally very quickly, with travel times as in the downward-transport scenario. Those in the zeolitized tuff-walled portion of the chimney should migrate extremely slowly, as in the upward-transport scenario

A Conceptual Model and Preliminary Estimate of Potential Tritium Migration from the Benham (U-20c) Site, Pahute Mesa, Nevada Test Site

U-20c is the site of a large below-water-table nuclear test near the Nevada Test Site boundary. A conceptual model of potential groundwater migration of tritium from U-20c is constructed and quantitatively evaluated in this report. The lower portion of the collapse chimney at Benham is expected to intersect 200 m of permeable rhyolite lava, overlain by similar thicknesses of low-permeability zeolitized bedded tuff, then permeable welded tuff. Vertical groundwater flow through the chimney is predicted to be minimal, horizontal transport should be controlled by the regional groundwater flow. Analytic solutions treating only advective transport indicate 1 to 2 km of tritium movement (95% confidence interval 0.7--2.5 km) within 5 years after test-related pressure-temperature transients have dissipated. This point lies at the axis of a potentiometric surface trough along the west edge of Area 20, Nevada Test Site. Within 25 years, movement is predicted to extend to 3 km (95% confidence interval 2--5 km) approximately to the intersection of the trough and the Nevada Test Site boundary. Considering the effects of radioactive decay, but not dispersion, plume concentration would fall below Safe Drinking Water Act standards by 204 years, at a predicted distance of 11 km (95% confidence interval 7--31 km). This point is located in the eastern portion of the Timber Mountain Caldera moat within the Nellis Air Force Range (military bombing range)

Continued investigations of the occurrence of water in Pahute Mesa emplacement holes

Periodically, water has been observed in emplacement boreholes drilled for underground testing of nuclear weapons at Pahute Mesa, Nevada Test Site, and is often at levels elevated above the predicted local water table. Water which may provide a means to transport residual radionuclides away from weapon tests may originate as fluids introduced during drilling, from naturally perched groundwater draining into the borehole, or from penetration of the local groundwater table. Lithium-bromide (Li-Br) tracer is being used to evaluate both the origin and movement of these borehole waters. The drilling fluid used to drill the final 100 meters of borehole U-19bh was chemically labeled with LiBr tracer. Lack of significant increase in borehole Br inventory over time indicates that standing water in U-9bh is not returned drilling fluid. Possible sources for the standing water are drilling fluid infiltrated above the bottom 100 in or natural water from a perched or shallower-than-expected saturated zone. The minimum detectable Darcy velocity of water passing through U-19bh is 0.3 m/yr. Borehole U-19bk has a water level approximately 50 in above the predicted pre-drilling water level. Initial water samples were collected from U-19bk to characterize the borehole water quality prior to adding the tracer. The major-ion analytical results of U-19bk along with historical water quality analyses of Water Well 20 and water well UE-19c show that all three waters are similar in character and therefore the water in U-19bk may be either residual drilling fluids originating from Water Well 20 and UE-19c or naturally occurring Pahute Mesa groundwater. LiBr tracer was added to the U-19bk borehole and samples for tracer analysis were collected one month later. For the one month period, no detectable loss of Br was observed. Over this short time period, the minimum detectable Darcy velocity is 10.6 m/yr