Journal articles: 'Ground water-surface water interface'

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Puckett, Larry J., Celia Zamora, Hedeff Essaid, John T. Wilson, Henry M. Johnson, Michael J. Brayton, and Jason R. Vogel. "Transport and Fate of Nitrate at the Ground-Water/Surface-Water Interface." Journal of Environmental Quality 37, no. 3 (May 2008): 1034–50. http://dx.doi.org/10.2134/jeq2006.0550.

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Riveros-Iregui, Diego A., and Jennifer Y. King. "Isotopic evidence of methane oxidation across the surface water-ground water interface." Wetlands 28, no. 4 (December 2008): 928–37. http://dx.doi.org/10.1672/07-191.1.

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Bobba, A. Ghosh. "Ground Water-Surface Water Interface (GWSWI) Modeling: Recent Advances and Future Challenges." Water Resources Management 26, no. 14 (September 14, 2012): 4105–31. http://dx.doi.org/10.1007/s11269-012-0134-x.

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Legeas, M., J. Carré, and Ph Mérot. "Effect of Wastewater Injection on Ground Water Quality." Water Science and Technology 25, no. 12 (June 1, 1992): 283–86. http://dx.doi.org/10.2166/wst.1992.0360.

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Effluents from the treatment plant of Saint Jean de Monts and Saint Hilaire de Riez have been injected into a confined ground water for twelve years. This ground water is connected with the sea. Effluent floats on the surface of the aquifer and it disperses by dilution at the freshwater/salt water interface. The aquifer acts as a direct overflow pipe. The injection of effluent has preserved the quality of waters in the coastal area and in the Breton Marsh.

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Browne, Bryant A., and Nathan M. Guldan. "Understanding Long-Term Baseflow Water Quality Trends Using a Synoptic Survey of the Ground Water-Surface Water Interface, Central Wisconsin." Journal of Environmental Quality 34, no. 3 (May 2005): 825–35. http://dx.doi.org/10.2134/jeq2004.0134.

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Tsou, Ming-Shu, and Donald O. Whittemore. "User Interface for Ground-Water Modeling: ArcView Extension." Journal of Hydrologic Engineering 6, no. 3 (June 2001): 251–57. http://dx.doi.org/10.1061/(asce)1084-0699(2001)6:3(251).

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Vroblesky, D. A., L. C. Rhodes, J. F. Robertson, and J. A. Harrigan. "Locating VOC Contamination in a Fractured-Rock Aquifer at the Ground-Water/Surface-Water Interface Using Passive Vapor Collectors." Ground Water 34, no. 2 (March 1996): 223–30. http://dx.doi.org/10.1111/j.1745-6584.1996.tb01882.x.

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Melvold, Kjetil, Thomas Schuler, and Gaute Lappegard. "Ground-water intrusions in a mine beneath Høganesbreen, Svalbard: assessing the possibility of evacuating water subglacially." Annals of Glaciology 37 (2003): 269–74. http://dx.doi.org/10.3189/172756403781816040.

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AbstractEvacuation of the ground-water intruding into a coal mine beneath Høganesbreen, Svalbard, is difficult and expensive. To solve this problem, it was proposed that the mine be connected to the ice–bedrock interface. Pumping hot water from the mine should establish a flow path along the glacier bed where the ground-water would drain gravitationally. In this paper, we assess the requirements for maintaining such a drainage system in open-channel conditions. To obtain the bedrock topography, we determined the ice thickness by ground-penetrating radar and subtracted it from the surface elevation measured by global positioning system. A measured temperature profile at the site where the mine should connect to the glacier bed (140m depth) revealed that the basal ice is below the pressure-melting point. The locations of major subglacial conduits were estimated using a hydraulic-potential approach. We adopted a model oftime-dependent discharge through a Röthlisberger channel to calculate a set of scenarios using different flow-law parameters. Results of the simulations suggest that for the given conditions, water flow would be pressurized, thereby inhibiting the gravitational drainage of the mine.

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Gusmeroli, A., and G. Grosse. "Ground penetrating radar detection of subsnow slush on ice-covered lakes in interior Alaska." Cryosphere 6, no. 6 (December 6, 2012): 1435–43. http://dx.doi.org/10.5194/tc-6-1435-2012.

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Abstract. Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. The frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe traveling condition onto lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow slush is almost impossible our understanding on overflow processes is still very limited and geophysical methods that allow water and slush detection are desirable. In this study we demonstrate that a commercially available, lightweight 1 GHz, ground penetrating radar system can detect and map extent and intensity of overflow. The strength of radar reflections from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of overflow also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by overflow.

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Langevin, Christian D., and David M. Bean. "Ground water vistas: A graphical user interface for the MODFLOW family of ground water flow and transport models." Ground Water 43, no. 2 (March 2005): 165–68. http://dx.doi.org/10.1111/j.1745-6584.2005.0016.x.

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Guo, Haipeng, and Jiu Jimmy Jiao. "Impact of Coastal Land Reclamation on Ground Water Level and the Sea Water Interface." Ground Water 45, no. 3 (May 2007): 362–67. http://dx.doi.org/10.1111/j.1745-6584.2006.00290.x.

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Gusmeroli, A., and G. Grosse. "Ground penetrating radar detection of subsnow liquid overflow on ice-covered lakes in interior Alaska." Cryosphere Discussions 6, no. 4 (July 31, 2012): 3079–99. http://dx.doi.org/10.5194/tcd-6-3079-2012.

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Abstract. Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. This frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe access to these lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow liquid overflow (SLO) is almost impossible our understanding on SLO processes is still very limited and geophysical methods that allow SLO detection are desirable. In this study we demonstrate that a commercially available, lightweight 1GHz, ground penetrating radar system can detect and map extent and intensity of SLO. Radar returns from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of SLO also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by SLO.

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Goforth, Tom, and Chris Hayward. "Seismic reflection investigations of a bedrock surface buried under alluvium." GEOPHYSICS 57, no. 9 (September 1992): 1217–27. http://dx.doi.org/10.1190/1.1443337.

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Seismic reflection techniques were used to characterize a bedrock surface buried under alluvium near a construction site on the campus of Baylor University in Waco, Texas. One of the objectives of the study was to determine if either compressional or shear seismic profiling could be used to reduce the number of engineering boreholes required to determine the bedrock depth and relief prior to building construction. The upper few meters of the alluvium is dry but the lower portion is below the water table, making the bedrock surface a difficult target for compressional waves. The compressional reflection coefficient at the water table is an order of magnitude greater than that at the bedrock surface, and the dry alluvium reduces the signal bandwidth such that the two reflections cannot be distinguished. Also, the multimode Rayleigh ground roll, traveling along the surface at about half the speed of the compressional wave, swamps the reflections. By using shear waves to profile the alluvium/bedrock interface, it was possible to avoid the water table and ground roll problems associated with compressional profiling. Walkaway survey results and analytical models presented demonstrate that shear waves do not “see” the water table, and masking of the bedrock target by the reflection at the dry/wet alluvium interface does not occur. Nor was ground roll a problem because the Love “ground roll,” traveling at a velocity almost as fast as the shear body wave, moves across the geophone spread before the return of the shallow reflections. Common depth point (CDP) and optimum offset shear profiles are presented. Uncertainty in determining the depth to bedrock from the seismic data was estimated to be 3 ft (0.9 m), which is sufficiently accurate to be useful in reducing the number of preconstruction boreholes required in the Brazos floodplain.

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Ford, T. E., and Robert J. Naiman. "Groundwater–Surface Water Relationships in Boreal Forest Watersheds: Dissolved Organic Carbon and Inorganic Nutrient Dynamics." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 1 (January 1, 1989): 41–49. http://dx.doi.org/10.1139/f89-006.

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Dissolved organic carbon (DOC) and inorganic nutrients (NH4-N, NO3-N, soluble total N, PO4-P, soluble total P, and Si) were measured in ground and surface waters in the Matamek River drainage network, Quebec, Canada. In general, concentrations of carbon and nitrogen were significantly higher in groundwater than in surface water (up to 340% for DOC and up to 700% for total N). No significant difference was detected for phosphorus whereas considerable variation occurred for silicon, with significantly higher groundwater concentrations at 50% of the study sites. We hypothesize that (1) groundwater is a source of DOC and nitrogen in these systems and (2) nutrients introduced through groundwater seepage are rapidly utilized via oxidative, biotic processes within the hyporheal zone or at the sediment–water interface.

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Hadi, M. Pramono, Ramdani Salam, and Rahim Achmad. "Groundwater resources mapping for small island using Geoelectrical Technique the case study of Ternate Island." Indonesian Journal of Geography 51, no. 1 (April 30, 2019): 49. http://dx.doi.org/10.22146/ijg.41242.

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The measurement of 2D geo-electrical using Wenner Alpha configuration was conducted in the shore line of northern part of Ternate island, in order to know the depth of interface and to analyze the aquifers in conjunction with estimation of ground water potential. Water quality analysis is also conducted in some dug wells, such as in situ water temperature, electrical conductivity, pH, turbidity, dissolved oxygen, and salinity.Due to laboratory analysis, the values of measured parameters of water quality from some dug wells meets to the standards referred, especially for drinking water. The result of interpretation from geo-electrical data showed the depth of interface less than 10m. From a drilled well data near shore line, indicate about 5m deep of interface. Base on geo-electrical survey, water quality analysis and field observation can be concluded that Ternate Island has limited potential of ground water, especially related to amount of fresh ground water. Which is now days, no alternative source yet of clean water for domestic use.

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Ibrahimova, A. R. "Role of surface water in the formation of underground water in Aghstafachai-Ganjachai interfluve and its usage prospects." Azerbaijan Oil Industry, no. 3 (March 15, 2020): 58–62. http://dx.doi.org/10.37474/0365-8554/2020-3-58-62.

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With the purpose of water resources estimation of Aghstafachai-Ganjachai interfluve, geophysical surveys have been carried out. As a result, based on the well data, the maps were developed and interface conditions of the territory specified. The tectonic structure of Aghstafachai-Ganjachai interfluve lowland is associated with the formation of a sole artesian basin on its territory. Aghstafachai, Hasansu, Tovuzchai, Zeyemchai, Shamkirchai, Goshgarchai, Ganjachai and Kurekchai, being the main source of groundwater recharge, created a combined alluvial cone on the territory. The underground water of these rivers were studied in the sloping plain and the estimation of its volume carried out as well. It was revealed that the underground water on a large part of studied territory is fresh and less mineralized. From the bacteriological point of view, it is clean water. The content of microelements and harmful chemical substances in the water does not exceed the standards set for the drinkable water. Despite the long-term usage, the quality of the underground water, the mineralization degree and chemical composition remain unchanged. The regime of underground water is characterized with the irrigated climate type. Hydrogeological indexes and the parameters of ground water horizon in the studied area justify the possibility of their research for water supply.

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Yechieli, Yoseph. "Fresh-Saline Ground Water Interface in the Western Dead Sea Area." Ground Water 38, no. 4 (July 2000): 615–23. http://dx.doi.org/10.1111/j.1745-6584.2000.tb00253.x.

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Hövelmann, Jörn, Christine Putnis, and Liane Benning. "Metal Sequestration through Coupled Dissolution–Precipitation at the Brucite–Water Interface." Minerals 8, no. 8 (August 10, 2018): 346. http://dx.doi.org/10.3390/min8080346.

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The increasing release of potentially toxic metals from industrial processes can lead to highly elevated concentrations of these metals in soil, and ground- and surface-waters. Today, metal pollution is one of the most serious environmental problems and thus, the development of effective remediation strategies is of paramount importance. In this context, it is critical to understand how dissolved metals interact with mineral surfaces in soil–water environments. Here, we assessed the processes that govern the interactions between six common metals (Zn, Cd, Co, Ni, Cu, and Pb) with natural brucite (Mg(OH)2) surfaces. Using atomic force microscopy and a flow-through cell, we followed the coupled process of brucite dissolution and subsequent nucleation and growth of various metal bearing precipitates at a nanometer scale. Scanning electron microscopy and Raman spectroscopy allowed for the identification of the precipitates as metal hydroxide phases. Our observations and thermodynamic calculations indicate that this coupled dissolution–precipitation process is governed by a fluid boundary layer at the brucite–water interface. Importantly, this layer differs in composition and pH from the bulk solution. These results contribute to an improved mechanistic understanding of sorption reactions at mineral surfaces that control the mobility and fate of toxic metals in the environment.

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Singer, Catherine K., and Chris A. Martin. "A Comparison of Surface Mulch Type on Patterns of Above- and Below-ground Temperature and Surface Net Radiation in a Drip-irrigated Desert Landscape." HortScience 40, no. 4 (July 2005): 1105E—1106. http://dx.doi.org/10.21273/hortsci.40.4.1105e.

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Mulches applied to landscape surfaces can moderate soil temperatures by changing the surface heat energy balance and conserve soil water by reducing evaporation rates. In the Southwest, decomposing granite is commonly used as landscape mulch. However, organic mulches, such as pine residue mulch and shredded tree trimmings, are becoming more available as industry by-products. Recent impetus toward water conservation and recycling forest and urban tree waste into urban landscapes has increased the need to better understand how such mulch types effect the temperature, moisture. and light quality of drip-irrigated landscapes typically found in the Southwest. We compared effects of three mulches, two organic (composted ponderosa pine residue and shredded urban tree trimmings) and one inorganic (Red Mountain Coral decomposing granite), turf grass, and bare soil applied to 14 drip-irrigated landscape research plots on below-ground soil temperatures at depths of 5 cm and 30 cm, temperatures at the mulch-soil interface, mulch surface temperatures, diel mulch surface net radiation, and albedo. Below-ground soil temperatures were more buffered by organic mulches, and mulch-soil interface temperatures were lower under organic mulch than inorganic mulches. Inorganic mulch daytime surface temperatures were lower than organic mulch surface temperatures. Nighttime net radiation values were less negative over organic mulches than inorganic mulches and albedo was significantly higher for the inorganic mulch and bare soil treatments. These results provide evidence to show that organic surface mulches have higher resistances to heat transfer than inorganic mulches, which could improve landscape plant water and nutrient use efficiencies by lowering high summer root zone temperatures.

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Boulton, G. S., and K. E. Dobbie. "Consolidation of sediments by glaciers: relations between sediment geotechnics, soft-bed glacier dynamics and subglacial ground-water flow." Journal of Glaciology 39, no. 131 (1993): 26–44. http://dx.doi.org/10.1017/s0022143000015690.

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AbstractA theory of subglacial consolidation is developed which shows how the meltwater flux beneath a glacier leaves a consolidation signature from which many important glacier-dynamic properties can be inferred. Conditions under which water is discharged through channels or in a thin film at the ice—bed interface or by ground-water flow are discussed, and it is concluded that glaciers flowing over aquifers of high transmissibility can induce deep circulation patterns quite different from non-glacial circulation. Examples of glacial pre-consolidation profiles in sediments from The Netherlands and England are used to illustrate how basal melting rates, subglacial ground-water flow patterns, ice overburden, basal shear stress, ice-surface profile and the amount of sediment removed by erosion can be inferred.

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Boulton, G. S., and K. E. Dobbie. "Consolidation of sediments by glaciers: relations between sediment geotechnics, soft-bed glacier dynamics and subglacial ground-water flow." Journal of Glaciology 39, no. 131 (1993): 26–44. http://dx.doi.org/10.3189/s0022143000015690.

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AbstractA theory of subglacial consolidation is developed which shows how the meltwater flux beneath a glacier leaves a consolidation signature from which many important glacier-dynamic properties can be inferred. Conditions under which water is discharged through channels or in a thin film at the ice—bed interface or by ground-water flow are discussed, and it is concluded that glaciers flowing over aquifers of high transmissibility can induce deep circulation patterns quite different from non-glacial circulation. Examples of glacial pre-consolidation profiles in sediments from The Netherlands and England are used to illustrate how basal melting rates, subglacial ground-water flow patterns, ice overburden, basal shear stress, ice-surface profile and the amount of sediment removed by erosion can be inferred.

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Al-Emami, Omar. "Investigation of soil-steel interface behavior of Iraqi soil by direct shear apparatus." MATEC Web of Conferences 162 (2018): 01003. http://dx.doi.org/10.1051/matecconf/201816201003.

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Soil - structure interaction is an important theme observed in many civil engineering structures like fondations. The interface shear strength plays a significant role in the analysis and design of many structures constructed above or under the ground. In this study, a total of 28 specimens were tested at vertical stresses of 100, 200, and 400 kPa using direct shear apparatus under consolidated drained condition. A silty sand soil, as per USCS classification system was prepared in the laboratory at different water contents (4.5%, 8.8%, and 12.5%) and voids ratios (0.4, 0.6, 0.8, and 1). The frictional resistance of this soil was measured. The soil samples were also sheared against three steel surfaces of different textures (smooth, moderate-rough, and rough). The experimental results showed that the steel surface texture is an effective factor in soil-steel interface shear strength. The interface shear strength of the rough steel surface was found higher than smooth and semi-rough steel surfaces. In addition to the surface roughness, the water content and void ratio also play important roles in interface shear strength.

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Yeager, Tom, Jeff Million, Claudia Larsen, and Bob Stamps. "Florida Nursery Best Management Practices: Past, Present, and Future." HortTechnology 20, no. 1 (February 2010): 82–88. http://dx.doi.org/10.21273/horttech.20.1.82.

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Florida container nurseries face the challenge of maintaining profitability while protecting the environment by improving the efficiency of water and fertilizer use. Best management practices (BMPs) provide irrigation and fertilization guidelines for meeting this challenge. BMPs are economically and technologically feasible to implement and they focus on the ground- and surface water quality issues of the state. However, increasing nursery participation in the statewide BMP program is crucial as the industry continues to expand and interface with urbanization.

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Moore, LS. "Water chemistry of the coastal saline lakes of the Clifton-Preston Lakeland system, south-western Australia, and its influence on stromatolite formation." Marine and Freshwater Research 38, no. 5 (1987): 647. http://dx.doi.org/10.1071/mf9870647.

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The water chemistry of Lake Clifton, the adjacent lakes and the regional ground water was investigated to aid in the elucidation of the factors responsible for the restriction of living stromatolites to Lake Clifton. The ionic composition of water in the lakes is proportionally similar to sea water, but the ground water is enriched in calcium and bicarbonate and is of lower salinity (1-2 g I-1). The salinities of the lakes ranged from 7 to 369 g l-1 during 1984 but, in contrast to the other lakes, Clifton remained less saline than sea water throughout the year. Ground waters from an unconfined aquifer on the eastern shore made a large contribution to the annual lake water budget of Lake Clifton, maintaining lake water salinity at less than 35 g l-1 and modifying the chemical composition of the sediment-water interface where stromatolites form. Living, lithified stromatolites occur along the eastern shore of Lake Clifton. They are formed by a benthic microbial community rich in Scytonema. The Stromatolites co-exist with an abundant metazoan fauna, but do not appear to be limited by grazing. Clearly defined zones of ground-water intrusion were found along the eastern foreshore and areas of differential ground-water discharge were associated with morphologically distinctive stromatolites. Occurrence of stromatolites and regions of ground-water discharge in Lake Clifton are consistently associated. It is suggested that the intruding ground waters in Lake Clifton provide a chemical environment conducive to the formation of calcified stromatolites.

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Heron, ML, PE Dexter, and BT McGann. "Parameters of the air-sea interface by high-frequency ground-wave Doppler radar." Marine and Freshwater Research 36, no. 5 (1985): 655. http://dx.doi.org/10.1071/mf9850655.

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A 30-MHz ground-wave ocean surface radar has been deployed inside the Great Barrier Reef where the water is sheltered from ocean swell. The spatial resolution of the radar is 3 km radially and 3.5� in azimuth. In each cell a 102.4-s time series is used to determine radial surface currents, wind directions, root- mean-square wave heights and wind speeds. Coincident observations of sea-wave spectra, surface currents and boundary-layer winds are used to evaluate the radar performance and to modify some of the methods of data analysis to suit these conditions. Surface current values are observed by the radar to an accuracy of �0.05 m s-1, wind directions to �10� , root-mean-square wave heights to 0.15 m and wind speeds to �3 m s-1. In some spectra, the peak in the second-order continuum caused by the non-directional sea- wave spectrum is not resolved from a second-order resonance line. This disallows the derivation of the period of the dominant sea wave on a routine basis.

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Rábade, H. G., P. Vellando, F. Padilla, and R. Juncosa. "A coupled FE model for the joint resolution of the shallow water and the groundwater flow equations." International Journal of Numerical Methods for Heat & Fluid Flow 24, no. 7 (August 26, 2014): 1553–69. http://dx.doi.org/10.1108/hff-05-2012-0123.

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Purpose – A new coupled finite element model has been developed for the joint resolution of both the shallow water equations, that governs the free surface flow, and the groundwater flow equation that governs the motion of water through a porous media. The paper aims to discuss these issues. Design/methodology/approach – The model is based upon two different modules (surface and ground water) previously developed by the authors, that have been validated separately. Findings – The newly developed software allows for the assessment of the fluid flow in natural watersheds taking into account both the surface and the underground flow in the way it really takes place in nature. Originality/value – The main achievement of this work has dealt with the coupling of both models, allowing for a proper moving interface treatment that simulates the actual interaction that takes place between surface and groundwater in natural watersheds.

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Zhang, Pin, Ren-Peng Chen, Huai-Na Wu, and Yuan Liu. "Ground settlement induced by tunneling crossing interface of water-bearing mixed ground: A lesson from Changsha, China." Tunnelling and Underground Space Technology 96 (February 2020): 103224. http://dx.doi.org/10.1016/j.tust.2019.103224.

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Groffman, R. "The Upper Water Table: A Reactive Interface Between Ground Water and Surficial Biogeochemical Processes in a Shallow Alluvial Aquifer." Mineralogical Magazine 62A, no. 1 (1998): 543–44. http://dx.doi.org/10.1180/minmag.1998.62a.1.287.

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Zhang, Yi, Wenbing Wu, Guoxiong Mei, and Longchen Duan. "THREE-DIMENSIONAL CONSOLIDATION THEORY OF VERTICAL DRAIN BASED ON CONTINUOUS DRAINAGE BOUNDARY." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 25, no. 2 (February 19, 2019): 145–55. http://dx.doi.org/10.3846/jcem.2019.8071.

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To remedy the limitation that the conventional drainage boundary only considers two extreme cases of pervious and impervious boundaries, the consolidation theory of vertical drain is derived by applying the continuous drainage boundary, and its validity is also proven. Based on the obtained solutions, the excess pore water pressure and the average degree of consolidation under the continuous drainage boundary condition are analyzed, and the effect of the drainage capacity of the top surface, the smear effect and the well resistance on consolidation are explored. Furthermore, the practicality of this theory is also validated by the comparison with experimental data. Results confirm that the complete and continuous process of the ground top surface can be changed from no drainage to a complete drainage by adjusting the value of the interface parameter b. Higher value of the interface parameter b means a stronger water permeability of the foundation, resulting in a faster dissipation of excess pore water pressure and a faster consolidation. Meanwhile, the vertical drainage of the vertical drain cannot be neglected in calculation even though vertical drains are based on a horizontal seepage. Moreover, the smear effect and the well resistance play an important role on consolidation.

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Hanzlík, Josef, and Anna Maria Camus. "Transfer of trispolypyridineruthenium(II) chelates in their ground and excited states across the water/1,2-dichloroethane interface." Collection of Czechoslovak Chemical Communications 56, no. 1 (1991): 130–39. http://dx.doi.org/10.1135/cccc19910130.

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Transfer of trispolypyridineruthenium(II) chelates of the type [Ru(chel)3]2+, where chel is 2,2’-bipyridine, 2,2’-bipyrimidine or 2,2’-bipyrazine, in their ground states across the water/1,2-dichloroethane interface was classified as the reversible transfer of a divalent cation. Thermodynamic and transport parameters characterizing this transfer were obtained from voltammetric measurements. Photoexcitation of these chelates gives rise to the photoinduced charge transfer across the water/1,2-dichloroethane interface.

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Webb, Ryan W., Keith Jennings, Stefan Finsterle, and Steven R. Fassnacht. "Two-dimensional liquid water flow through snow at the plot scale in continental snowpacks: simulations and field data comparisons." Cryosphere 15, no. 3 (March 19, 2021): 1423–34. http://dx.doi.org/10.5194/tc-15-1423-2021.

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Abstract. Modeling the multidimensional flow of liquid water through snow has been limited in spatial and temporal scales to date. Here, we present simulations using the inverse TOUGH2 (iTOUGH2) model informed by the model SNOWPACK, referred to as SnowTOUGH. We use SnowTOUGH to simulate snow metamorphism, melt/freeze processes, and liquid water movement in two-dimensional snowpacks at the plot scale (20 m) on a sloping ground surface during multi-day observation periods at three field sites in northern Colorado, USA. Model results compare well with sites below the treeline and above the treeline but not at a site near the treeline. Results show the importance of longitudinal intra-snowpack flow paths (i.e., parallel to ground surface in the downslope direction and sometimes referred to as lateral flow), particularly during times when the snow surface (i.e., snow–atmosphere interface) is not actively melting. At our above-treeline site, simulations show that longitudinal flow can occur at rates orders of magnitude greater than vertically downward percolating water flow at a mean ratio of 75:1 as a result of hydraulic barriers that divert flow. Our near-treeline site simulations resulted in slightly less longitudinal flow than vertically percolating water, and the below-treeline site resulted in negligible longitudinal flow of liquid water. These results show the increasing influence of longitudinal intra-snowpack flow paths with elevation, similar to field observations. Results of this study suggest that intra-snowpack longitudinal flow may be an important process for consideration in hydrologic modeling for higher-elevation headwater catchments.

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Yamaguchi, Tetsuji, Takuma Sawaguchi, Manabu Tsukada, Seiichi Hoshino, and Tadao Tanaka. "Mineralogical changes and associated decrease in tritiated water diffusivity after alteration of cement–bentonite interfaces." Clay Minerals 51, no. 2 (May 2016): 279–87. http://dx.doi.org/10.1180/claymin.2016.051.2.13.

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AbstractAlteration of cement–bentonite interfaces and accompanying changes in diffusivity of tritiated water (HTO) was investigated experimentally using intact, hardened cement-paste specimens. The alteration by carbonate solution was accompanied by mineralogical changes at the interface and a decrease in the HTO diffusivity to ∼70 ± 7%of the initial value after a 180-day period. Another alteration in contact with compacted bentonite was accompanied by mineralogical changes at the interface and a decrease in the HTO diffusivity to ∼71 ± 10% of the initial value after a 600-day period. The changes in the diffusivity were considerably less than those observed for mixed specimens of ground, granulated hardened cement paste and bentonite where the diffusivity decreased to 20% of the initial value over 180 days. The results were extrapolated to 15 y under simple assumptions and showed good agreement with those observed in the cement–argillite interface at Tournemire URL (France). Such an explanation enhances confidence in the assessment of the alteration of cement-bentonite systems and might be a basis for using the data and models obtained in the long-term assessment of radioactive waste disposal.

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Mandlburger, G., and B. Jutzi. "FEASIBILITY INVESTIGATION ON SINGLE PHOTON LIDAR BASED WATER SURFACE MAPPING." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-1 (September 26, 2018): 109–16. http://dx.doi.org/10.5194/isprs-annals-iv-1-109-2018.

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Abstract. The recent advent of single photon sensitive airborne LiDAR (Light Detection And Ranging) sensors has enabled higher areal coverage performance at the price of an increased outlier rate and a lower ranging accuracy compared to conventional Multi-Photon LiDAR. Single Photon LiDAR, in particular, uses green laser light capable of penetrating clear shallow water. Although primarily designed for large area topographic mapping, the technique can also be used for mapping the water surface and shallow water bathymetry. In this contribution we investigate the capability of Single Photon LiDAR for large area mapping of water surface heights. While interface returns from conventional green-only bathymetric sensors generally suffer from water level underestimation due to the water penetration capabilities of green laser radiation, the specific questions are, if Single Photon LiDAR (i) is less affected by this well known effect due to the high receiver sensitivity and (ii) consequently delivers a higher number of water surface echoes. The topic is addressed empirically in a case study by comparing the water surface responses of Single Photon LiDAR (Navarra, Spain) and Multi-Photon Topo-Bathymetric LiDAR (Neubacher Au, Austria) for selected water bodies with a horizontal water surface (reservoirs, ponds). Although flown at different altitudes, both datasets are well comparable as they exhibit the same strip point density of ca. 14points/m2. The expected superiority of Single Photon LiDAR over conventional green-only bathymetric LiDAR for mapping water surfaces could not be verified in this investigation. While both datasets show good agreement compared to a reference water level when aggregating points into cells of 10&times;10m2 (mean deviations &lt;5cm), higher resolution Single Photon LiDAR based water surface models (grid size 1&ndash;5m) show a systematic water level underestimation of 5&ndash;20cm. However, independently measured ground truth observations and simultaneous data acquisition of the same area with both techniques are necessary to verify the results.

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Xiong, Meng, Pengfei He, Yanhu Mu, and Xinlei Na. "Modeling of Concrete-Frozen Soil Interface from Direct Shear Test Results." Advances in Civil Engineering 2021 (January 2, 2021): 1–11. http://dx.doi.org/10.1155/2021/7260598.

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The shear behaviors of concrete-frozen soil interface are important for analyzing the performance of engineering structures buried in the frozen ground. In this paper, a series of direct shear tests were carried out to determine the concrete-soil interface behaviors at different test temperatures (19°C, −1°C, −3°C, and −5°C) and initial water contents (9.2%, 13.1%, 17.1%, and 20.8%) of soils. The interface shear behaviors, including the shear stress versus horizontal displacement, interface cohesion, and interface friction coefficient, were analyzed based on the test results. Then, a simple, nonlinear model was proposed and verified for the interface shear behaviors. The results show that the effect of initial water content and test temperature on the interface shear behavior is significant, and the peak stress increases with the increasing initial water content and decreasing test temperature. The interface cohesion is sensitive to the test temperature and initial water content, while the interface friction coefficient is insensitive to both the factors. The parameters of the simple nonlinear model can be gained by back-analyzing the test results. The predictions made by the proposed model are found to be in good agreement with the experimental results.

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Fulazzaky, M. A., Z. Yusop, I. Ibrahim, and A. H. M. Kassim. "A new technique using the aero-infiltrometer to characterise the natural soils based on the measurements of infiltration rate and soil moisture content." Hydrology and Earth System Sciences Discussions 10, no. 10 (October 25, 2013): 12717–51. http://dx.doi.org/10.5194/hessd-10-12717-2013.

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Abstract. Infiltration rate (f) and soil moisture content (θ) are the important factors for water resources management. Accurate measurements of these factors are not so readily available in most farmlands since present measuring equipments are not really suitable. This paper proposes the measuring device that uses a simple method to measure the rate of water infiltration into the ground and to determine the percentage of water contained in the soil. The two empirical equations which formulated on the basis of power regression models of plotting f vs. air pressure dropping rate (P) and θ vs. P are proposed to evaluate the dynamic properties of soil-water and soil–air interface from a three-phase system. All the parameters in equations have physical meanings, and experimental data validation shows that the equations are sufficiently accurate. Aero-infiltrometer was used to measure both the variations of f and θ at three natural soil sites to contribute to operational water management issues and soil texture identification. In the future, new research opportunities on basic knowledge of air diffusion into the ground will contribute to more versatile techniques in measurement of water infiltration.

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Fulazzaky, M. A., Z. Yusop, I. Ibrahim, and A. H. M. Kassim. "A new technique using the aero-infiltrometer to characterise the natural soils based on the measurements of infiltration rate and soil moisture content." Hydrology and Earth System Sciences Discussions 11, no. 2 (February 28, 2014): 2515–53. http://dx.doi.org/10.5194/hessd-11-2515-2014.

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Abstract. Infiltration rate (f) and soil moisture content (θ) are the important factors for water resources management. Accurate measurements of these factors are not so readily available in most farmlands since present measuring equipments are not really suitable. This paper proposes the measuring device that uses a simple method to measure the rate of water infiltration into the ground and to determine the percentage of water contained in the soil. The two empirical equations which formulated on the basis of power regression models of plotting f vs. air pressure dropping rate (P) and θ vs. P are proposed to evaluate the dynamic properties of soil–water and soil–air interface from a three-phase system. All the parameters in equations have physical meanings, and experimental data validation shows that the equations are sufficiently accurate. Aero-infiltrometer was used to measure both the variations of f and θ at three natural soil sites to contribute to operational water management issues and soil texture identification. In the future, new research opportunities on basic knowledge of air diffusion into the ground will contribute to more versatile techniques in measurement of water infiltration.

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Hachem, S., C. R. Duguay, and M. Allard. "Comparison of MODIS-derived land surface temperatures with ground surface and air temperature measurements in continuous permafrost terrain." Cryosphere 6, no. 1 (January 13, 2012): 51–69. http://dx.doi.org/10.5194/tc-6-51-2012.

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Abstract. Obtaining high resolution records of surface temperature from satellite sensors is important in the Arctic because meteorological stations are scarce and widely scattered in those vast and remote regions. Surface temperature is the primary climatic factor that governs the existence, spatial distribution and thermal regime of permafrost which is a major component of the terrestrial cryosphere. Land Surface (skin) Temperatures (LST) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra and Aqua satellite platforms provide spatial estimates of near-surface temperature values. In this study, LST values from MODIS are compared to ground-based near-surface air (Tair) and ground surface temperature (GST) measurements obtained from 2000 to 2008 at herbaceous and shrub tundra sites located in the continuous permafrost zone of Northern Québec, Nunavik, Canada, and of the North Slope of Alaska, USA. LSTs (temperatures at the surface materials-atmosphere interface) are found to be better correlated with Tair (1–3 m above the ground) than with available GST (3–5 cm below the ground surface). As Tair is most often used by the permafrost community, this study focused on this parameter. LSTs are in stronger agreement with Tair during the snow cover season than in the snow free season. Combining Aqua and Terra LST-Day and LST-Nigh acquisitions into a mean daily value provides a large number of LST observations and a better overall agreement with Tair. Comparison between mean daily LSTs and mean daily Tair, for all sites and all seasons pooled together yields a very high correlation (R = 0.97; mean difference (MD) = 1.8 °C; and standard deviation of MD (SD) = 4.0 °C). The large SD can be explained by the influence of surface heterogeneity within the MODIS 1 km2 grid cells, the presence of undetected clouds and the inherent difference between LST and Tair. Retrieved over several years, MODIS LSTs offer a great potential for monitoring surface temperature changes in high-latitude tundra regions and are a promising source of input data for integration into spatially-distributed permafrost models.

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Jorgenson, M. T., and T. E. Osterkamp. "Response of boreal ecosystems to varying modes of permafrost degradation." Canadian Journal of Forest Research 35, no. 9 (September 1, 2005): 2100–2111. http://dx.doi.org/10.1139/x05-153.

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Permafrost degradation associated with a warming climate is second only to wildfires as a major disturbance to boreal forests. Permafrost temperatures have risen to 4 °C since the “Little Ice Age”, resulting in widespread thawing of permafrost. The mode of permafrost degradation is highly variable, and its topographic and ecological consequences depend on the interaction of slope position, soil texture, hydrology, and ice content. We partitioned this variability into 16 primary modes: (1) thermokarst lakes from lateral thermomechanical erosion; (2) thermokarst basins after lake drainage; (3) thaw sinks from subsurface drainage of lakes; (4) glacial thermokarst of ice-cored moraines; (5) linear collapse-scar fens associated with shallow groundwater movement; (6) round isolated collapse-scar bogs from slow lateral degradation; (7) small round isolated thermokarst pits from surface thawing; (8) polygonal thermokarst mounds from advanced ice-wedge degradation; (9) mixed thermokarst pits and polygons from initial ice-wedge degradation; (10) irregular thermokarst mounds from thawing of ice-poor silty soils; (11) sinkholes and pipes resulting from groundwater flow; (12) thermokarst gullies and water tracks from surface-water flow; (13) thaw slumps related to slope failure and thawing; (14) thermo-erosional niches from water undercutting of ice-rich shores; (15) collapsed pingos from thawing of massive ice in pingos; and (16) nonpatterned ground from thawing of ice-poor soils. These modes greatly influence how thermokarst changes or disrupts the ground surface, ecosystems, human activities, infrastructure, and the fluxes of energy, moisture, and gases across the landair interface.

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Eigenbrod, K. D., and G. J. A. Kennepohl. "Moisture Accumulation and Pore Water Pressures at Base of Pavements." Transportation Research Record: Journal of the Transportation Research Board 1546, no. 1 (January 1996): 151–61. http://dx.doi.org/10.1177/0361198196154600117.

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A unique mechanism based on extensive field and laboratory studies is presented to account for certain premature failures of flexible pavements in cold areas like those in Scandinavia and in northern parts of Canada and the United States. Water condensing at the interface between pavement and granular base accumulates at subzero temperatures resulting in excess moisture in this zone. During the thaw period of the uppermost base layer, the excess water in the aggregate is trapped between impervious layers of frozen ground to the sides and below as well as an impervious layer of asphalt pavement above. Because of this containment, high pore water pressures can occur, leading to loss in shear strength of the base material and thus to failure of the pavement structure itself. It was found that under special conditions, excess moisture can accumulate in granular base with a silt content greater than 20 percent and very high pore water pressures can develop during initial thaw at the pavement-soil interface. With silt contents of less than 2 percent, excess pore water pressures can be avoided during thaw. It was also shown that when a clean open gravel is placed below the pavement on top of a silty base material, moisture accumulation near the pavement-base interface can be prevented, and thus also the development of high pore water pressures.

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Zhang, Shunfu, Changjun Liu, Chuanke Li, Sili Long, Jian Zhou, and Qiyi Zhang. "Analysis of Water Cycle in Weizhou Island of Beihai City, Guangxi Province, Part II: Study On Groundwater Exploitation Plan." MATEC Web of Conferences 246 (2018): 02047. http://dx.doi.org/10.1051/matecconf/201824602047.

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To relieve the drop of groundwater and seawater intrusion in Weizhou Island caused by overexploitation, the analysis model of precipitation-runoff and variable-density groundwater flow in Weizhou Island was established and the model’s parameter identification results were used to investigate groundwater level and seawater/freshwater interface changes under different groundwater exploitation plans. Thereafter, a rational groundwater exploitation plan could be made to prevent the lowering of groundwater levels caused by ground water overexploitation and ecological deterioration caused by seawater intrusion. This could help accelerating the recovery of ground water and maintaining ecological system.

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Wheless, G. H., and G. T. Csanady. "Instability waves on the air–sea interface." Journal of Fluid Mechanics 248 (March 1993): 363–81. http://dx.doi.org/10.1017/s0022112093000801.

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We used a compound matrix method to integrate the Orr–Sommerfeld equation in an investigation of short instability waves (λ < 6 cm) on the coupled shear flow at the air–sea interface under suddenly imposed wind (a gust model). The method is robust and fast, so that the effects of external variables on growth rate could easily be explored. As expected from past theoretical studies, the growth rate proved sensitive to air and water viscosity, and to the curvature of the air velocity profile very close to the interface. Surface tension had less influence, growth rate increasing somewhat with decreasing surface tension. Maximum growth rate and minimum wave speed nearly coincided for some combinations of fluid properties, but not for others.The most important new finding is that, contrary to some past order of magnitude estimates made on theoretical grounds, the eigenfunctions at these short wavelengths are confined to a distance of the order of the viscous wave boundary-layer thickness from the interface. Correspondingly, the perturbation vorticity is high, the streamwise surface velocity perturbation in typical cases being five times the orbital velocity of free waves on an undisturbed water surface. The instability waves should therefore be thought of as fundamentally different flow structures from free waves: given their high vorticity, they are akin to incipient turbulent eddies. They may also be expected to break at a much lower steepness than free waves.

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Xie, Zhenghui, Zhenhua Di, Zhendong Luo, and Qian Ma. "A Quasi-Three-Dimensional Variably Saturated Groundwater Flow Model for Climate Modeling." Journal of Hydrometeorology 13, no. 1 (February 1, 2012): 27–46. http://dx.doi.org/10.1175/jhm-d-10-05019.1.

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Abstract In this study, a quasi-three-dimensional, variably saturated groundwater flow model was developed by approximately dividing the three-dimensional soil water and groundwater flow into an unsaturated vertical soil water flow and a horizontal groundwater flow to simulate the interactions among soil water, groundwater, and vegetation. The developed model consists of a one-dimensional unsaturated soil water flow model with the water table as the moving boundary using an adaptive grid structure for a vertical soil column formed based on discrete grid cells in a horizontal domain, a two-dimensional groundwater flow model for the horizontal domain, and an interface model connecting the two components for the horizontal grid cells in the domain. Synthetic experiments by the model were conducted to test the sensitivities of the model parameters of river elevation, ground surface hydraulic conductivity, and surface flux, and the results from the experiments showed the robustness of the proposed model under different conditions. Comparison of the simulation by the model and that by a full three-dimensional scheme showed its feasibility and efficiency. A case of stream water conveyance in the lower reaches of the Tarim River was then applied to validate the developed model for simulation of the water table elevations at the Yingsu section. Finally, a numerical experiment by the model for the Tarim River basin was conducted to discuss the groundwater latent flow for large-scale high-relief topography with stream water conveyance. The results show that the model can simulate the water table reasonably well.

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Shao, Hai Yan, Zhen Hai Zhang, Ke Jie Li, Jian Wang, Tao Xu, Shuai Hou, and Liang Zhang. "Water Hazard Detection Based on 3D LIDAR." Applied Mechanics and Materials 668-669 (October 2014): 1174–77. http://dx.doi.org/10.4028/www.scientific.net/amm.668-669.1174.

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Autonomous off-road navigation is a highly complicated task for a robot or unmanned ground vehicle (UGV) owing to the different kinds of obstacles it could encounter. In-particular, water hazards such as puddles and ponds are very common in outdoor environments and are hard to detect even with ranging devices due to the specular nature of reflection at the air water interface. In recent years, many researches to detect the water bodies have been done. But there still has been very little work on detecting bodies of water that could be navigation hazards, especially at night. In this paper, we used Velodyne HDL-64ES2 3D LIDAR to detect water hazard. The approach first analyzes the data format and transformation of 3D LIDAR, and then writes the data acquisition and visualizations algorithm, integrated data based on ICP algorithm. Finally according the intensity distribution identifies the water hazard. Experiments are carried out on the experimental car in campus, and results show the promising performance.

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Buchner, Jens S., Ute Wollschläger, and Kurt Roth. "Inverting surface GPR data using FDTD simulation and automatic detection of reflections to estimate subsurface water content and geometry." GEOPHYSICS 77, no. 4 (July 1, 2012): H45—H55. http://dx.doi.org/10.1190/geo2011-0467.1.

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A new inversion scheme for common-offset ground-penetrating radar measurements at multiple antenna separations was proposed, which is intermediate between inverting of picked reflectors using ray-tracing and full-waveform inversion. The measurements are modeled similarly to the real data using 2D finite-difference time-domain simulations. These simulations are obtained with a parameterized model of the subsurface that consists of several layers with constant dielectric permittivity and an explicit representation of the layers’ interfaces. Then, reflections in the modeled and in the real data are detected automatically, and the reflections of interest of the real data are selected manually. The sum of squared residuals of the reflections’ traveltime and amplitude is iteratively minimized to estimate subsurface water content and geometry, i.e., the position and shape of the layer interfaces. The method was first tested with a synthetic data set and then applied to a real data set. The comparison of the method’s result with ground-truth data showed an agreement with the subsurface geometry within [Formula: see text] and with the water content, a difference less than [Formula: see text] volume.

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Deidda, G. P., and R. Balia. "An ultrashallow SH‐wave seismic reflection experiment on a subsurface ground model." GEOPHYSICS 66, no. 4 (July 2001): 1097–104. http://dx.doi.org/10.1190/1.1487057.

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An SH‐wave seismic reflection experiment was conducted to evaluate the feasibility and cost effectiveness of reflection imaging ultrashallow targets commonly encountered in engineering, groundwater, and environmental investigations. It was carried out on a purpose‐built subsurface ground model consisting of a concrete layer, at a depth from 2.85–5 m, and a low‐velocity overburden (<80 and 150 m/s for S‐ and P‐waves, respectively), constituted of filling material, with the water table 2.60 m deep. High‐quality CDP data, acquired by using a 10‐kg sledgehammer and newly designed horizontal detectors, allowed us to obtain an extremely detailed stacked section with a minimal amount of processing. Uncertainty in determining the depth and horizontal dimensions of the concrete model was estimated to be 0.2 and 0.3 m, respectively; however, the dominant frequencies lower than 150 Hz, the low‐transmission coefficient at the upper interface, and the relatively high velocity (900 m/s) of the concrete layer prevented us from resolving the layer thickness. The experiment demonstrates that when overburden materials exhibit low velocities (a common condition in near surface), the SH‐wave seismic reflection method is a reliable, detailed, and cost‐effective technique to image ultrashallow targets, even in disturbed material and below the water table.

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Miller, Richard D., Don W. Steeples, and Michael Brannan. "Mapping a bedrock surface under dry alluvium with shallow seismic reflections." GEOPHYSICS 54, no. 12 (December 1989): 1528–34. http://dx.doi.org/10.1190/1.1442620.

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Shallow seismic‐reflection techniques were used to image the bedrock‐alluvial interface, near a chemical evaporation pond in the Texas Panhandle, allowing optimum placement of water‐quality monitor wells. The seismic data showed bedrock valleys as shallow as 4 m and accurate to within 1 m horizontally and vertically. The normal‐moveout velocity within the near‐surface alluvium varies from 225 m/s to 400 m/s. All monitor‐well borings near the evaporation pond penetrated unsaturated alluvial material. On most of the data, the wavelet reflected from the bedrock‐alluvium interface has a dominant frequency of around 170 Hz. Low‐cut filtering at 24 dB/octave below 220 Hz prior to analog‐to‐digital conversion enhanced the amplitude of the desired bedrock reflection relative to the amplitude of the unwanted ground roll. The final bedrock contour map derived from drilling and seismic‐reflection data possesses improved resolution and shows a bedrock valley not interpretable from drill data alone.

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Fannin, R. J., and J. Jaakkola. "Hydrological response of hillslope soils above a debris-slide headscarp." Canadian Geotechnical Journal 36, no. 6 (December 1, 1999): 1111–22. http://dx.doi.org/10.1139/t99-074.

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The Jamieson Creek debris slide initiated in thin soils over a competent bedrock surface, on a planar section of hillslope, during a heavy rainstorm in November 1990. An array of automated piezometers and tensiometers was placed along a 22 m wide section of the headscarp in 1997 to monitor the temporal variation of pore-water pressures. Interpretation of the data addresses the hydrologic response to the storms in October and November 1997. The piezometers, which were designed for installation by driving, reveal very localized responses in what otherwise appears to be a uniform soil matrix. Peak positive pressures occur at the time of maximum rainfall intensity. The tensiometers indicate the hydrological response at the ground surface appears uncoupled from that at the bedrock interface. Implications of the extreme spatial variability in pore-water pressure are evaluated for conceptual models of hillslope hydrology. The assumption of parallel seepage flow is widely adopted in translational slope stability analyses, imposing a linear distribution of pore-water pressure with depth. None of the reported field data are consistent with such a linear distribution with depth or a uniform response across the slope.

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Le Moigne, Patrick, François Besson, Eric Martin, Julien Boé, Aaron Boone, Bertrand Decharme, Pierre Etchevers, et al. "The latest improvements with SURFEX v8.0 of the Safran–Isba–Modcou hydrometeorological model for France." Geoscientific Model Development 13, no. 9 (September 1, 2020): 3925–46. http://dx.doi.org/10.5194/gmd-13-3925-2020.

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Abstract. This paper describes the impact of the various changes made to the Safran–Isba–Modcou (SIM) hydrometeorological system and demonstrates that the new version of the model performs better than the previous one by making comparisons with observations of daily river flows and snow depths. SIM was developed and put into operational service at Météo-France in the early 2000s. The SIM application is dedicated to the monitoring of water resources and can therefore help in drought monitoring or flood risk forecasting on French territory. This complex system combines three models: SAFRAN, which analyses meteorological variables close to the surface, the ISBA land surface model, which aims to calculate surface fluxes at the interface with the atmosphere and ground variables, and finally MODCOU, a hydrogeological model which calculates river flows and changes in groundwater levels. The SIM model has been improved first by reducing the infrared radiation bias of SAFRAN and then by using the more advanced ISBA multi-layer surface diffusion scheme to have a more physical representation of surface and ground processes. In addition, more accurate and recent databases of vegetation, soil texture, and orography were used. Finally, in mountainous areas, a sub-grid orography representation using elevation bands was adopted, as was the possibility of adding a reservoir to represent the effect of aquifers in mountainous areas. The numerical simulations carried out with the SIM model covered the period from 1958 to 2018, thereby providing an extensive historical analysis of the water resources over France.

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Martin, Chris A., and S. Bhattacharya. "Below-ground Pot-in-Pot (PIP) System and Substrate Moisture Regimen Affect Growth of Two Desert Trees." HortScience 33, no. 3 (June 1998): 504b—504. http://dx.doi.org/10.21273/hortsci.33.3.504b.

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Acacia smalli (sweet acacia) and Cercidium praecox (palo brea) trees were grown during June–Oct. 1997 outdoors in full sun in 19-L containers positioned either PIP or above ground on the soil surface. The 38-L PIP holder containers were placed in the ground. Cyclic pulses of water were controlled by soil moisture sensors interfaced with electronic solenoid irrigation valves. Rooting substrate water potentials at 20 cm below the substrate surface and 10 cm inside the container wall were consistently maintained at either >–0.01 MPa (wet) or between –0.02 and –0.03 MPa (dry) for both above ground and PIP container substrates. Less than 1.25 cm of rainfall occurred during the study period. No incidences of rooting-out were observed with PIP trees. Maximum root-zone temperatures of PIP containers were 19 °C lower than temperatures measures in substrate of aboveground containers. Growth of both species was stimulated by the wet substrate regimen compared with the dry regimen. Positioning trees in a below-ground PIP configuration under the wet substrate regimen stimulated growth of sweet acacia compared with the PIP dry regimen. The PIP configuration did not affect growth of palo brea trees.

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Wang, Qing, and Yupeng Shen. "Calculation and Interpretation of Ground Penetrating Radar for Temperature and Relative Water Content of Seasonal Permafrost in Qinghai-Tibet Platea." Electronics 8, no. 7 (June 27, 2019): 731. http://dx.doi.org/10.3390/electronics8070731.

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Due to the seasonal permafrost thawing, the Qinghai–Tibet Highway has a depression and instability of the roadbed. In order to obtain the ablation interface and water content characteristics of seasonal permafrost areas, non-destructive ground penetrating radars using electromagnetic wave detection methods are widely used. Regarding the imaging of the ablation interface in permafrost regions, this paper proposes a high-precision procedure for seasonal permafrost media using waveform difference analysis, electromagnetic wave attenuation attribute calculation and relative wave impedance conversion. It improves the resolution and division accuracy of the imaging. In addition, the study demonstrates a method to calculate the temperature and water content of the ablation zone by mining attenuation attribute, relative wave impedance attribute, absolute instantaneous amplitude attribute and the weighted average frequency attribute parameters under the constraints of the measured data. This method has high accuracy and high efficiency and can be used in the rapid calculation of temperature and water content of seasonal permafrost on the Qinghai–Tibet Highway.

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Journal articles on the topic 'Ground water-surface water interface'

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