【摘要】 总结了我国九个省区主要经济自然区土壤污染元素背景值图编制中取得的一些主要经验与成果。更多还原

【Abstract】 The determination of drafting unit, the diuision of grades of drawing in background maps and some other problems in the statistic map of the division of grades of background contents in nine natural areas of econmics of China have been discussed and saummed up in the paper. The determinative principle of drafting units is based on the main and comprehensive factors which affect regional distribution of elements contents in soils; significant test ia used to divide grades of background contents.更多还原