Application of TM Images on Estimation of Organic Carbon in Surface Soil in Burned Areas

摘要

Based on remote sensing and field measured data,this paper discussed the effectiveness of selecting optimal variables with a cross-variable by VIP≥1 and used partial least squares regression(PLSR) to build a model for estimating surface soil organic carbon of burned area. The results showed that: variables such as K-Tl,K.-T2,TM2,TM4,and TM5/TM4 have larger contribution to the model,their VIP values were 1.5116,1.1915,1.3545,1.2242 and 1.4275,respectively. The intensity index of Tasseled Cap transformation has a higher value than the original bands of TM2 and TM4,and the contribution of bands ratio is higher than the single band. Further,the PLS model was applied to estimating the special distribution of soil organic carbon (SOC) content (unit in g.kg-1) in entire study area. We conclude that different fire intensity affected on soil organic carbon variously,and followed an order as high intensity>moderate intensity>light intensity. The average density of surface soil organic carbon was 12.53 kg per m2,soil organic carbon storage was 202.46×106kg,the fire-released soil organic carbon was 29.8× 106kg in study area.