Leakage rates are evaluated for a landfill barrier system having a compacted clay liner (CCL) underlain by a vadose zone of variable thickness. A numerical unsaturated flow model SEEP/W is used to simulate the moisture flow regime and steady-state leakage rates for the cases of unsaturated zones with different soil types and thicknesses. The results of the simulations demonstrate that harmonic ...

In this study, a stochastic model for transient saturated–unsaturated flow is developed based on the Karhunen-Loeve expansion of the input random soil properties combined with a perturbation method. The log-transformed saturated hydraulic conductivity f ðxÞ and the soil pore size distribution parameter aðxÞ are assumed to be normal random functions with known covariances. We decompose f ðxÞ and...

The true efficacy of a programme of agricultural mitigation measures within a catchment to improve water quality can be determined only after a certain hydrologic time lag period (subsequent to implementation) has elapsed. As the biophysical response to policy is not synchronous, accurate estimates of total time lag (unsaturated and saturated) become critical to manage the expectations of polic...

This paper describes a comprehensive sensitivity study that was performed using high performance parallel computers to understand the importance of input parameters to a transient partially saturated finite element seepage analysis for a levee with separate soil layers of sand, silty sand, and clay. Seepage flow in this paper refers to the type of flow of water that occurred through the failed ...

Critical path analysis and percolation theory are known to predict accurately dc and low frequency ac electrical conductivity in strongly heterogeneous solids, and have some applications in statistics. Much of this work is dedicated to review the current state of these theories. Application to heterogeneous porous media has been slower, though the concept of percolation was invented in that con...

seismic ground motion is profoundly affected by geometrical and mechanical properties of soil deposits overlaying bedrock. local seismic ground response of saturated soil deposits was studied in literature by applying the effects of soil stress state and index properties on the strain-dependent normalized shear modulus reduction, g/g0, and damping ratio, d, curves in an equivalent linear analys...

A graph is Ramsey unsaturated if there exists a proper supergraph of the same order with the same Ramsey number, and Ramsey saturated otherwise. We present some conjectures and results concerning both Ramsey saturated and unsaturated graphs. In particular, we show that cycles Cn and paths Pn on n vertices are Ramsey unsaturated for all n ≥ 5. 1 Results and Conjectures Throughout this article, r...

measurement of soil saturated hydraulic conductivity, ks, is normally affected by flow patterns such as macro pore; however, most current techniques do  not differentiate flow types, causing major problems in describing water and chemical flows within the soil matrix. this study compares eight models for scaling ks and predicted matrix and macro pore ks, using a database composed of 50 datasets...

[1] Estimates of aquifer parameters, saturated hydraulic conductivity, and drainable porosity were obtained by an analytical solution of the two-dimensional Laplace equation with linearized boundary conditions and were compared to prescribed parameters in a finite element model that simulated drainage of a coupled system of unsaturated/saturated flow. Boundary conditions prerequisite for the an...