This paper summarizes the progression of modeling efforts of infiltration, percolation, and seepage conducted between 1984 and 2008 to evaluate feasibility, viability, and assess compliance of a repository in the unsaturated zone for spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nevada. Scientific understanding of infiltration in a desert environment, unsaturated percol...

On a stepped spillway, the steps contribute to some dissipation of the turbulent kinetic energy, while free-surface aeration can be very intense. The aim of this study is to investigate the two-phase flow properties on a gabion stepped spillway, including both free-surface and seepage flows, as well as the bubbly flow interactions at the gabion interface. Detailed measurements were conducted in...

With decreases in acid deposition, nitrogen : phosphorus (N:P) ratios in lakes are anticipated to decline, decreasing P limitation of phytoplankton and potentially changing current food web dynamics. This effect could be particularly pronounced in the Adirondack Mountains of New York State, a historic hotspot for effects of acid deposition. In this study, we evaluate spatial patterns of nutrien...

Methane on Mars is a topic of special interest because of its potential association with microbial life. The variable detections of methane by the Curiosity rover, orbiters, and terrestrial telescopes, coupled with methane's short lifetime in the martian atmosphere, may imply an active gas source in the planet's subsurface, with migration and surface emission processes similar to those known on...

Previous studies indicate that the local aquifer systems in the Mid-Levels, a highly urbanized coastal area in Hong Kong, have commonly been affected by leakage from water mains. The identification of leakage locations was done by conventional water quality parameters including major and trace elements. However, these parameters may lead to ambiguous results and fail to identify leakage locatio...

rade control structures are used to control bed erosion in steep small rivers mostly in the mountains. scour downstream of this structure can lead to failure. over the past years, the effect of different variables on this phenomena have been studied, however the effect of upward seepage which is common due to head difference of the banks water table or water surface level between the upstream a...

Acid mine drainage (AMD) was the main environmental problem facing the mining industry. For AMD had high heavy metals content and low pH, the compacted sewage sludge might be a barrier for tailings whose oxidation and weathering produced AMD, with its own carbon source, microorganism reduction ability and impermeability. To study the heavy metals environmental risk, under the simulate AMD, the ...

Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The g...

Is the recently found seepage groundwater on Mars pure H2O, or mixed with salts and other antifreeze compounds? Given the surface conditions of Mars, it is unlikely that pure water could either exist in its liquid state or have shaped Mars’ fluid erosional landforms (gullies, channels, and valley networks). More likely is that Mars’ seepage groundwater contains antifreeze and salt compounds tha...

[1] Numerical models of bedrock valley development generally do not include weathering explicitly. Nevertheless, weathering is an essential process that acts in concert with the transport of loose debris by seepage and runoff to form many bedrock valleys. Here we propose a numerical model for bedrock valley development that explicitly distinguishes weathering and the transport of loose debris a...