摘要
为更加深入地揭示核素示踪土壤侵蚀的内在机理,在Arcgis Geostatistics模块的支持下,运用地统计学方法研究了宁镇地区137Cs与210Pbex的空间异质性及其坡面分布特征。研究结果表明:(1)核素所特有的理化性质决定了137Cs与210Pbex的空间异质性及其坡面分布格局的与众不同。137Cs与210Pbex较大的块金值说明了土壤侵蚀及耕作活动等随机性因素对其空间分布的决定性影响,这正是它们能够示踪土壤侵蚀的原因所在。(2)137Cs属中等程度的空间自相关,其坡面分布格局能够较好地反映出地形这一结构性因素在其中所施加的影响,示踪土壤侵蚀的结果也应更为全面、合理,并具有宏观性。210Pbex的空间相关性很弱,说明其对随机性因素的影响有着更为敏感的响应,在揭示坡面侵蚀的细部特征方面应能做得更好。(3)137Cs与210Pbex坡面分布格局存在较大的差异,这一方面说明两者在初始沉降布局、部分理化性质,以及对各种变异影响因素的响应等诸多方面还存在着不小的差异;另一方面也在提示,两者示踪土壤侵蚀进程的结果很难通过数学模型的调整而达成一致。
In order to explore in depth intrinsic mechanism of using nuclide tracer technique to study soil erosion deeply, spatial heterogeneity and distribution of ^137 Cs ＆ ^210Pbex. in a slope in Ningzhen region were studied with the geostatistics method based on the module of Arcgis Geostatistics. Results shows that the unique physicochemical properties of ^137 Cs ＆ ^210Pbex make them distinct from others in spatial heterogeneity and distribution characteristics in slope. The biggish Nugget of ^137 Cs ＆ ^210Pbex indicates that their spatial distribution is definitively influenced by random factors such as soil erosion, farming practices, etc.. And it is why theycan be used to trace soil erosion. The medium degree of spatial autocorrelation and distribution patterns of 137 Cs on slope reflect preferably that landform as a structural factor can influence its spatial distribution. Results of the tracing of soil erosion using ^137Cs should be more comprehensive, more reasonable, and more macroseopieal. The very week spatial autocorrelation of ^210Pbex explain that its spatial distribution is more sensitive to the influence of random factors. And it is better at exposing details of soil erosion. The distribution patterns on a slope differ quite much between ^137 Cs ＆ ^210Pbex, which, on the one hand, indicates that they differ from each other quite sharply in their initial sedimentation layout, partial physicochemical properties, and responses to various affeeting factors for variation, etc. and on the other hand, it also hints that the courses of soil erosion traced with ^137 Cs ＆ ^210Pbex, can hardly reach an agreement even through adjustment of their calculation models.
出处
《土壤学报》
CAS
CSCD
北大核心
2011年第4期673-682,共10页
Acta Pedologica Sinica
基金
江苏省教育厅重点项目(09KJA170002)
江苏省土木工程与防灾减灾重点实验室项目(JSCE0702)
国家自然科学基金项目(40873071)和国家自然科学基金重点项目(41030751)联合资助
