成都平原土壤pH的时空分布特征及影响因素研究

Temporal-spatial Distribution Characteristics and Influence Factors of Soil pH in the Chengdu Plain

在ArcGIS9．0软件系统平台上，利用1982年172个样点和2002年的117个样点分析成都平原土壤pH值的时空变异特征。结果表明，成都平原样点间表层（0～20cm）土壤pH值由1982年的6．95±0．90降低到2002年的6．70±0．78，平均降低了3．60％。但从全区来看，平原内仍有占研究区面积53．71％的土壤其pH值增加，仅46．29％的土壤其pH值减少；其中都江堰——彭州一线、邛崃和蒲江的交界处以及成都、龙泉驿和双流的接壤处土壤pH值增加；中部变幅较小；金堂、蒲江等局部地区土壤pH值急剧下降，局部地区下降幅度达1．0个单位。该区土壤pH值变化明显受成土母质、土地利用方式、施肥措施和工业发展的影响。

The temporal-spatial variability of soil pH in the Chengdu basin is expressed by the spatial analytic approaches such as ordinary kriging （OK） on the basis of the software ArcGIS Desktop 9.0. The average content of soil pH, which changes from 6.95 ± 0.90 in 1982 to 6.70 ± 0.78 in 2002 with a decrease of 3.60 %, has shown a decreasing tendency during 20 years. Although there is just a little decrease in the average content of soil pH, soil pH of 46.29% area in the basin decreases and that of 53.71 % increases. The area distribution of soil pH is different, soil pH increases in the northeast part such as from Dujiangyan to Pengzhou, the boundary between Qionglai and Pujiang, the place where Chengdu marches with Longquanyi and Shuangliu; it changes slowly in the central part; but soil pH in some places such as Jingtang and Pujiang decreases sharply. The change of soil pH is remarkably influenced by soil parent material, land use types, fertilization measure and industry development.