عبدالرضا فاضلی

Soil is one of the most important and valuable sources in the world. In addition to being an important mainstream for plants growth, it is the main area for water transmission. Because of these, soil pollutant will affect groundwater and life of organisms will be in danger. The most important contaminants in the soil are hydrocarbons that are insoluble in water. These contaminants have been called Non Aqueous Phase Liquid (NAPL). With entry of oil in soil and groundwater, a wide range of water will be affected and this pollution increases with time. Groundwater remediation operation needs to predict the behavior of this type of pollution in an environment. Therefore, in this thesis, using the finite difference method and MATLAB software, initially movement and distribution of pollutants in groundwater is simulated. Then by employment of modeling results and GeneXproTools (Gene Expression Programming Software), four relationships have been achieved. By utilizing these four relations, comprehensive information about the movement and distribution of NAPL over time, and in different parts of the aquifer will be achieved. Input variables in this formula include the type of contaminants, pollutants discharge, leakage time and depth of the aquifer. Relationships obtained from GEP software that calculate the maximum and minimum amounts of pollution in vertical and radial dimensions, are the functional relationships in order to better identifying of contaminated areas with Dense Non Aqueous Phase Liquid and then improvement of water remediation operations. As the result shows, pollutant distribution rate in both radial and vertical directions will increase, with increase in time. Diffusion of pollutant has a linear relation with rate of spill, but when contaminant reaches to the bedrock, maximum amount of pollution in vertical direction will be close to a constant value. In each correlation for polluted area, increasing height of aquifer will affect on amount of pollution sp