In the firefighting and the graph searching problems, a contaminate spreads relatively quickly. We introduce a new model, on directed acyclic graphs, in which the contamination spreads slowly. The model was inspired by the efforts to stem the lava flow from the Eldfell volcano in ∗ Partially supported by grants from NSERC. 92 N.E. CLARKE ET AL. Iceland. The contamination starts at a source, onl...

Upper Gotvand dam is constructed on the Karun River located in the south west of Iran. In this paper, 2D and 3D models of the dam together with the foundation and abutments were constructed and several seepage analyses were carried out. Then the gypsum veins scattered throughout the foundation ground and also the seepage pattern were included in the models, hence the dissolution law of gypsum, ...

In the present study, analytical solutions are obtained for two-dimensional advection dispersion equation for conservative solute transport in a semi-infinite heterogeneous porous medium with pulse type input point source of uniform nature. The change in dispersion parameter due to heterogeneity is considered as linear multiple of spatially dependent function and seepage velocity whereas seepag...

1. House mouse Mus domesticus outbreaks in the grain-growing areas of south-eastern Australia occur irregularly and may be local or widespread, covering thousands of square kilometres. All natural and agricultural habitats are occupied when house mouse numbers are high, and the question we addressed was whether we can distinguish source and sink habitats within these agricultural landscapes so ...

Submarine groundwater discharge (SGD) into a shallow lagoon on the west coast of Mauritius Island (Flic-en-Flac) was investigated using radioactive ((3)H, (222)Rn, (223)Ra, (224)Ra, (226)Ra, (228)Ra) and stable ((2)H, (18)O) isotopes and nutrients. SGD intercomparison exercises were carried out to validate the various approaches used to measure SGD including radium and radon measurements, seepa...

seepage in earth fill dams is one of the important factors that may cause the erosion and slope instability if it is ignored. therefore, it is crucial to calculate the leakage discharge through the body of dam and foundation, to prevent economic and life hazards by considering technical and economical issues. in this research, the seepage analysis of the body and the stability of the upstream a...

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...

Extensive calcite fault cement has resulted from leakage of Santa Barbara basin fluids and hydrocarbons into the Refugio-Carneros fault, a north-bounding structure to the basin. Calcite cements are only found at the end segments of the 24-km (15-mi)-long fault zone, which has less than 150 m (490 ft) of maximum normal offset. The calcite is contemporaneous with fault movement, as evidenced by p...

Dissolved methane and high resolution bathymetry surveys were conducted over the Rock Garden region of Ritchie Ridge, along the Hikurangi margin, eastern New Zealand. Multibeam bathymetry reveals two prominent, northeast trending ridges, parallel to subduction along the margin, that are steep sided and extensively slumped. Elevated concentrations of methane (up to 10 nM, 10× background) within ...