Estimating spatial distribution of soil organic carbon for the Midwestern United States using historical database.
Estimating spatial distribution of soil organic carbon for the Midwestern United States using historical database.
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DOI：
10.1016/j.chemosphere.2014.12.027
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发表时间：
2015-05
期刊：
影响因子：
8.8
通讯作者：
Sandeep Kumar
中科院分区：
文献类型：
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作者：
Sandeep Kumar
土壤有机碳（SOC）是影响土壤健康、全球气候变化、作物生产力和各种生态系统服务功能的最重要参数。因此，在更大的尺度上估计SOC是重要的。本研究进行了估计SOC池在区域尺度上使用的历史数据库收集的国家土壤调查工作人员。该研究的具体目标是使用地理加权回归克里金法（GWRK）放大美国中西部的SOC密度（kg C m−2）和总SOC库（Pg C），并将结果与使用3485个地理参考剖面数据的地理加权回归（GWR）获得的结果进行比较。本研究的结果支持以下结论：GWRK产生了令人满意的预测，具有较低的均方根误差（5.60 kg m−2），平均估计误差（0.01 kg m−2）和平均绝对估计误差（4.30 kg m−2），以及较高的R2（0.58）和预测优度统计量（G= 0.59）值。与全局回归（R2= 0.28）相比，R2（0.45）大幅增加，这种方法的优越性显而易见。该地区的农田储存16.8 Pg SOC，其次是灌木（5.85 Pg）和森林（4.45 Pg）。中西部地区的SOC汇总总量范围为31.5 - 31.6 Pg。这项研究表明，GWRK方法明确地解决了空间依赖性和空间非平稳性问题，插值SOC密度在整个区域尺度。
Soil organic carbon (SOC) is the most important parameter influencing soil health, global climate change, crop productivity, and various ecosystem services. Therefore, estimating SOC at larger scales is important. The present study was conducted to estimate the SOC pool at regional scale using the historical database gathered by the National Soil Survey Staff. Specific objectives of the study were to upscale the SOC density (kg C m−2) and total SOC pool (Pg C) across the Midwestern United States using the geographically weighted regression kriging (GWRK), and compare the results with those obtained from the geographically weighted regression (GWR) using the data for 3485 georeferenced profiles. Results from this study support the conclusion that the GWRK produced satisfactory predictions with lower root mean square error (5.60 kg m−2), mean estimation error (0.01 kg m−2) and mean absolute estimation error (4.30 kg m−2), and higherR2(0.58) and goodness-of-prediction statistic (G= 0.59) values. The superiority of this approach is evident through a substantial increase inR2(0.45) compared to that for the global regression (R2= 0.28). Croplands of the region store 16.8 Pg SOC followed by shrubs (5.85 Pg) and forests (4.45 Pg). Total SOC pool for the Midwestern region ranges from 31.5 to 31.6 Pg. This study illustrates that the GWRK approach explicitly addresses the spatial dependency and spatial non-stationarity issues for interpolating SOC density across the regional scale.