drastic is known as the most prototype models of groundwater vulnerability assessment. the drastic constitutes from seven schematic parameters consisting: depth to groundwater, recharge to aquifer, aquifer geology, and surface soil texture, impact of vadoze zone and hydraulic conductivity. in this study the models parameters were extracted by the main schematic maps of model. instead using the ...

In this study, the general partial differential equation of unsteady groundwater flow through non-homogeneous and anisotropic aquifer was solved by the fully implicit finite difference method with control volume approach. The calibration of permeability and storage coefficients as model parameters was performed by a transformation technique and application of Powell's non-linear optimization me...

[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...

To describe flow or transport phenomena in porous media, relations between aquifer hydraulic conductivity and effective porosity can prove useful, avoiding the need to perform expensive and time consuming measurements. The practical applications generally require the determination of this parameter at field scale, while most of the empirical and semiempirical formulas, based on grain size analy...

Numerical models capable of simulating solute reactive transport in groundwater systems are often used as tools to assess the state of contaminated aquifer systems. Accurately simulating the fate and transport of solutes, however, is often hindered by a lack of information regarding the chemical reactions parameters that govern the fate of the solute. Furthermore, field and laboratory methods u...

BACKGROUND Extensive human activities and unplanned land uses have put groundwater resources of Shiraz plain at a high risk of nitrate pollution, causing several environmental and human health issues. To address these issues, water resources managers utilize groundwater vulnerability assessment and determination of protection. This study aimed to prepare the vulnerability maps of Shiraz aquifer...

[1] Hydraulic tomography is a cost-effective technique for characterizing the heterogeneity of hydraulic parameters in the subsurface. During hydraulic tomography surveys a large number of hydraulic heads (i.e., aquifer responses) are collected from a series of pumping or injection tests in an aquifer. These responses are then used to interpret the spatial distribution of hydraulic parameters o...

with respect to population growth and agricultural development in ardabil plain, vulnerability assessment of the plain aquifer is necessary for management of groundwater resources and the prevention of groundwater contamination. in this study, vulnerability of ardabil plain aquifer to pollution was evaluated by drastic method. drastic model was prepared by seven effective parameters on vulnerab...