香溪河流域土壤有机碳储量影响因素的空间相关性分析

采用第二次土壤普查资料估算了香溪河流域不同类型土壤的有机碳密度和碳库,并通过野外土样采集和室内测试获取土壤有机碳含量数据,选取信息熵模型定量研究香溪河流域不同土壤类型、地形地貌类型、成土母质类型、植被覆盖度、土壤厚度、坡度和土地利用方式与土壤有机碳密度之间的关系。研究结果表明,香溪河流域土壤有机碳总储量为75.18Tg,香溪河流域SOC密度主要集中在6.00~16.00kg/m2范围内,SOC密度呈现流域北部高、干流高,其他区域SOC密度高低相间的分布特征,这种分布特征与主要土壤类型和地形地貌类型的地理分布关系密切。香溪河流域各种土壤类型对各级有机碳密度的信息熵值差异明显,土壤类型对有机碳密度的影响作用与香溪河流域土壤有机碳密度与碳库计算结果一致,高山区,林地、农田和灌丛利于高密度有机碳的存储;植被覆盖度越高,越利于有机碳的存储;土壤厚度与有机碳密度的相关性高,而坡度与有机碳密度的相关性不明显;信息熵法实现了对各影响因子定量计算分析,结果较合理和可靠。 

Spatial correlation analysis on soil organic carbon and the influencing factors in the Xiangxi River Basin

Base on the information of national soil survey for the second time and the date come out of field collection and lab.test,this paper firstly studies organic carbon density and pool of different soil types in the Xiangxi River Basin,then chooses information statistics method which is based on information entropy principle to study the spatial relationship quantitatively between soil organic carbon density and its influencing factors,including soil types,topography and geomorphology,soil parent material,vegetation coverage,soil thickness,slope and diversity of the land use types in basin.The results show that the total organic carbon pool of the basin is 75.18 Tg,and soil organic carbon density mainly ranges from 6.00 to 16.00 kg/m2,the soil organic carbon density is high in the northern part of basin and main stream area,and the soil organic carbon density in the other areas of the basin is distributed alternately with high and low.The spatial distribution of soil organic carbon density is affected by the distribution of soil types and topography and geomorphology conditions.The differences of information entropy values for soil organic carbon density at various levels by different soil types are significant,which are broadly consistent with the analysis and compute results of SOC density and carbon storage in the Xiangxi River Basin.In the alpine zone,forest land,farmland and bush land are benefit for storage of soil organic carbon with high density.The soil organic carbon density is highly correlated with soil thickness,but the relevance between the slope and organic carbon density is not obvious.The results of information entropy method used in quantitative calculation and analysis on soil organic carbon density and each impact factors are more reasonable and reliable.