JIANG Zhen-jiao， BIAN Jian-min， ZHA En-shuang

（Environmental and Resources College, Jilin University, Changchun 130026，China）

Abstract：For the lack of samples, research on arsenic distribution on a lager scale has been misled. Here, a useful method is introduced and applied. Pseudo-cokriging has improved the former cokriging method, applying the available data, by the pseudo-cross variograms, the samples are completed. Qian’an County in western Jilin Province was selected as the research area to reveal the spatial variation characters of groundwater arsenic distribution in the phreatic aquifer, confined aquifers (Q3g,Q1b). The ratios of nugget to sill are 14.5%, 3.9% and 31.9%, and the variation of arsenic is controlled by the differences of the aquifers.The correlations between phreatic aquifer and confined aquifers are very good, and then, based on the Pseudo-cokring method , the samples from the phreatic aquifers have been used to smooth the samples from the two aquifers , and the results are compared with those obtained by ordinary Kriging method. The precisions of arsenic in confined aquifers have been advanced by 38.1% and 31.6% , respectively.

Key words：pseudo-crossvariagram; distribution of groundwater arsenic; evaluation precision; robust statistic analysis

EARTH AND ENVIRONMENT Vol. 39, No.1, Tot No.283, 2011, Page 56-62