Application of Ordinary Kriging in Mapping Soil Organic Carbon in Zambia  

作　　者：Lydia Mumbi CHABALA Augustine MULOLWA Obed LUNGU 

机构地区：[1]Department of Soil Science, University of Zambia, School of Agricultural Sciences, P.O. Box 32379, Lusaka (Zambia) [2]Department of Geomatic Engineering, University of Zambia, School of Engineering/National Remote Sensing Center, P.O. Box 32379, Lusaka (Zambia)

出　　处：《Pedosphere》2017年第2期338-343,共6页土壤圈（英文版）

基　　金：partially supported in finance by the Ministry of Education, Science and Vocational Training and Early Education, Zambia

摘　　要：The quantification of the pattern and spatial distribution of soil organic carbon （SOC） is fundamental to understand many ecosystem processes. This study aimed to apply ordinary kriging （OK） to model the spatial distribution of SOC in a selected part of Zambia. A total of 100 soil samples were collected from the study area and analyzed for SOC by determining soil oxidizable carbon using the Walkley-Black method. An automated fitting procedure was followed when modeling the spatial structure of the SOC data with the exponential semivariogram. The results indicated that the short range spatial dependence of SOC was strong with a nugget close to zero. The spatial autocorrelation was high to medium with a nugget to sill ratio of 0.25. The root mean square error of the predictions was 0.64, which represented 58.18% of the mean observed data for SOC. It can be concluded that the generated map could serve as a proxy for SOC in the region where evidence of spatial structure and quantitative estimates of uncertainty are reported. Therefore, the maps produced can be used as guides for various uses including optimization of soil sarapling.The quantification of the pattern and spatial distribution of soil organic carbon(SOC) is fundamental to understand many ecosystem processes. This study aimed to apply ordinary kriging(OK) to model the spatial distribution of SOC in a selected part of Zambia. A total of 100 soil samples were collected from the study area and analyzed for SOC by determining soil oxidizable carbon using the Walkley-Black method. An automated fitting procedure was followed when modeling the spatial structure of the SOC data with the exponential semivariogram. The results indicated that the short range spatial dependence of SOC was strong with a nugget close to zero. The spatial autocorrelation was high to medium with a nugget to sill ratio of 0.25. The root mean square error of the predictions was 0.64, which represented 58.18% of the mean observed data for SOC. It can be concluded that the generated map could serve as a proxy for SOC in the region where evidence of spatial structure and quantitative estimates of uncertainty are reported.Therefore, the maps produced can be used as guides for various uses including optimization of soil sampling.

关 键 词：exponential semivariogram geographical distribution geostatistical procedure oxidizable carbon spatial autocorrela-tion 

分 类 号：S153.6[农业科学—土壤学]