Geostatistics and GIS were used to analyze the spatial variability of the soil water characteristics in western semiarid area of Heilongjiang province. Irrigation management zone was established based on spatial distribution of the soil water characteristics and actual condition of the study area. Sampling by layered sampling method and calculating of the rational sampling number by best distri...

A quasi three-dimensional (QUASI 3-D) model is presented for simulating the subsurface water flow and solute transport in the unsaturated and in the saturated zones of soil. The model is based on the assumptions of vertical flow in the unsaturated zone and essentially horizontal groundwater flow. The 1-D Richards equation for the unsaturated zone is coupled at the phreatic surface with the 2-D ...

in this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. the model is derived from the framework of generalized biot theory. the fracture propagation is governed by a cohesive fracture model. the flow within the fracture zone is modeled by the lubrication equation. the displacement of solid phase, and...

mathematical simulation of flow toward drains is an important and indispensable stage in drainage design and management. many related models have been developed, but most of them simulate the saturated flow toward drains without a due consideration of the unsaturated zone. in this study, the two dimensional differential equation governing saturated and unsaturated flow in porous media is numeri...

We derive steady equilibria for lateral downslope moisture flow in an ide-alized thin closed layer as a solution to the 1D Richards' Equation. The equilibria are determined by two free parameters: the downslope flux and a boundary condition. Solutions exhibit a constant downslope flow speed and moisture content for the constant equilibrium flux, which is the product of the two. However where an...

An instrumentation system consisting of driven well-points, instrumentation bundles, and discrete sampling has been developed for monitoring subsurface conditions during the operation of air injection remediation systems. The driven well points provide intimate contact reducing the impact on the remediation process. The instrumentation bundles afford continuous monitoring of subsurface conditio...

[1] Most analytical and numerical models developed to analyze pumping test data focus on saturated flow below the water table. Traditionally the soil above the initial water table prior to pumping has been thought to have little influence on the test results and has usually been ignored. It is hypothesized that, if the unsaturated zone is capped by low-permeability soil, airflow in the unsatura...

Article Map