Abstract: Due to the inaccurate of the Kriging interpolation, it was difficult to accurately investigate and describe the scope of groundwater pollution under the condition of heterogeneous and low permeability geological. In order to explore methods to improve the accuracy of describing the scope of groundwater pollution and save construction costs, a groundwater pollution site in Shanghai was taken as the research object. The influence of mesh density of 40 m×40 m and 20 m×20 m on groundwater pollution range simulated by Kriging method and restoration project cost were analyzed, at the same time,the groundwater pollution range was determined by means of formation analysis combined with pit excavation,and the difference of pollution range was compared. The results showed that compared with the 40 m×40 m grid density, the amount of pollution groundwater simulated by interpolation was reduced by 57.0% when the sampling density was 20 m×20 m, and the cost of remediation engineering could be saved much greater than the increased cost of monitoring and investigation. Combined with stratum analysis and site pollution characteristics, pit excavation method were adopted in a concerted way to determine the actual pollution area of groundwater, the area of pollution decreased by 45.6% and the groundwater pollution volume decreased by 97.7% compared with the Kriging method(grid density of 20 m×20 m). By improving the density of the survey grid and combining it with the hydrogeological conditions and pit excavation which would facilitate the accurate description of groundwater treatment range.

Key words: pollution scope；accurate description, Kriging interpolation, pit excavation, groundwater pollution