Through the laboratory experiments, the mechanical properties of sandy gravel are obtained. Then, based on the slump tests, a modified sandy gravel model is developed by PFC (particle flow code of three dimensions), to which relevant microscopic parameters are assigned to numerically simulate the laboratory experiments. The laboratory test results are compared with that of the numerical simulat...

Measuring infiltration and leaching at the plot scale is difficult, especially for high hydraulic conductivity soils. Infiltration rate has been indirectly calculated at the plot scale by comparing surface runoff to rainfall. Direct measurement of infiltration and leaching beyond the point scale is typically limited to locations where land forming has been performed, e.g. infiltration ponds and...

regarding the role and importance of subsurface drainage in water table control, many studies have been made throughout the world to find out new techniques and more economical solutions, especially as related to different pipe envelope material and their installations. this research was conducted to investigate the use of rice husk, as drain envelope material, in drainage installations. in add...

Soils overlying two porphyry Cu deposits (Spence, Gaby Sur) and the Pampa del Tamarugal, Atacama Desert, Northern Chile were collected in order to investigate the extent to which saline groundwaters influence ‘‘soil’’ chemistry in regions with thick Miocene and younger sediment cover. Soil carbonate (calcite) was analyzed for C and O isotopes and pedogenic gypsum for S isotopes. Soil calcite is...

Endemic to the Namib Desert, Fairy Circles (FCs) are vegetation-free circular patterns surrounded and delineated by grass species. Since first reported the 1970's, many theories have been proposed to explain their appearance, but none provide a fully satisfactory explanation of their origin(s) and/or causative agent(s). In this study, we have evaluated an early hypothesis stating that edaphic m...

Seashores and river bottoms are constantly eroded by the flow processes. Grains of various types, including gravel, sand, silt, clay, mixed at different ratios, demonstrating varying characteristics, constituent materials these eroding land features. The present study quantifies importance geomechanical properties soils, with a large fraction granular material smaller portion fine grain particl...

Highly unsaturated soil mixtures (clay, sand and gravel) are used as building materials in many parts of the world, and there is increasing interest in understanding their mechanical and hydraulic behaviour. In the laboratory, xray computed tomography (XRCT) is becoming more widely used to investigate the microstructures of soils, however a crucial issue for such investigations is the choice of...

A new logistic regression (LR) model was used to predict the probability of nitrate contamination exceeding 4 mg/L in predominantly shallow, recently recharged groundwaters of the United States. The new model contains variables representing (1) N fertilizer loading (p < 0.001), (2) percent cropland-pasture (p < 0.001), (3) natural log of human population density (p < 0.001), (4) percent well-dr...

Physical changes that occur on the surface of fired shots due to firing and impact with soil may increase the dissolution of muniton metals. Increased metal dissolution could potentially increase metal transport and leaching, affecting metal concentrations in surface and groundwater. This research describes the relationship between the surface changes on fired tungsten-nickel-iron (94% W:2% Ni:...

Three pedons were selected representing the soil series of study area in Baiji city, which are Khadraniya, Al-Sharqat, and Manjour soils series, calcareous gypsiferous soils, to diagnose some micro-morphological Features horizons. Pedons morphologically described, disturbed undisturbed samples collected from each horizon. The presence (calcic) (gypsic) horizons has been diagnostic by morphologi...