Mapping soil organic matter using the topographic wetness index: A comparative study based on different flow-direction algorithms and kriging methods
文献类型：SCI/SSCI论文
| 作者 | Yang L.; Pei T. |
| 发表日期 | 2010 |
| 关键词 | Collocated cokriging Single-flow-direction (SFD) Multiple-flow-direction (MFD) Auto-correlation Cross-correlation Terrain variable Digital soil mapping spatial interpolation drainage networks northeast china black soil prediction elevation indicators regression topmodel models |
| 英文摘要 | Terrain attributes derived from digital elevation models have been used widely for mapping soil organic matter (SOM). Among these attributes, the topographic wetness index (TWI), an index for quantitatively indicating the balance between water accumulation and drainage conditions at the local scale, has been shown to correlate with SOM. However, TWIs used in most studies are calculated using a single-flow-direction (SFD) algorithm, which assumes that all water from a grid cell flows into only one neighboring cell. This assumption is not always valid, especially in areas with low relief where movement of water may be divergent. To overcome this SFD limitation, a multiple-flow-direction (MFD) algorithm has been developed, which distributes flow from a grid cell to several downslope neighbors. In this study we compared the effect of TWI Calculations based on SFD and MFD in predictive mapping of SOM by incorporating them into different kriging methods over a 51.76 km(2) area in Nenjiang County of northeastern China. We found that the MFD-based TWI was better correlated with SOM than was the SFD-based index. We then compared the accuracies of SOM maps which were derived from MFD-based TWI and SFD-based TWI incorporated by ordinary kriging (OK), simple kriging with varying local means (SKlm), kriging with external drift (KED) and collocated cokriging (CC). The MFD-based TWI, used as a secondary variable in SKlm and CC, outperforms the SFD-based TWI. For the different kriging methods, CC (incorporating either MFD-based TWI or SFID-based TWI) showed the best performance, and OK generated a better result than SKlm and KED. Both the MFD-based TWI and SFD-based TWI proved to be incompatible with KED and SKlm due to their numerical instability caused by the rough TWI surfaces. Among all predictive methods, CC incorporating the MFD-based TWI produced the best results. This is because: (1) the MFD-based TWI is best able to indicate quantitatively soil moisture and therefore has the strongest correlation with SOM; (2) CC is capable of utilizing effectively the spatial auto-correlation of SOM and the cross-correlation between SOM and the MFD-based TWI. (C) 2009 Elsevier Ltd. All rights reserved. |
| 出处 | Ecological Indicators |
| 卷 | 10 |
| 期 | 3 |
| 页 | 610-619 |
| 收录类别 | SCI |
| 语种 | 英语 |
| ISSN号 | 1470-160X |
| 源URL | [http://ir.igsnrr.ac.cn/handle/311030/23222]  |
| 专题 | 地理科学与资源研究所_历年回溯文献 |
| 推荐引用方式 GB/T 7714 | Yang L.,Pei T.. Mapping soil organic matter using the topographic wetness index: A comparative study based on different flow-direction algorithms and kriging methods. 2010. |
入库方式： OAI收割
来源：地理科学与资源研究所
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