土壤有机质是土壤固相部分的重要组成成分，也是陆地表层重要的碳库，其含量的快速、准确测定关乎农牧业生产活动安排与地表过程研究中关键参数的获取效率。为了探寻适合青藏高原高寒地区土壤有机质遥感反演的响应波段及遥感模型，实现区域像元尺度上的土壤表层有机质估算，本文利用Landsat8-OLI多光谱遥感数据与实地采样数据对青海湖流域表层(0 ~ 20 cm)土壤进行了有机质含量反演研究。结果表明：Landsat8-OLI影像的第5、6和7波段是青海湖流域土壤有机质含量的特征波段，基于这3个波段构建的土壤有机质遥感反演三元回归模型(R²=0.704，P<0.001)，经实测点验证(RMSE=8.66)与相关文献研究结果验证(RMSE=8.85)，精度高、稳定性强、预测趋势平稳。本研究不仅为高寒地区土壤有机质含量快速测定提供了一定的技术支持，也为高寒地区的碳库计算、土壤肥力评价、土壤碳循环、农作物估产、草地退化监测等提供了参考。

Soil organic matter (SOM) is an important component of soil solid phase, and it is also an important carbon pool of terrestrial ecosystem. At regionalscale, rapidly and accurately determining SOM content is critical for production activities of agriculture-animal husbandry and the efficiency for obtaining the key parameters of earth surface processes. To explore the remote sensing (RS) bands containing SOM information in multi-spectral RS data and to estimate SOM with RS technology over Qinghai-Tibet Plateau (QTP), the Landsat-8 OLI multi-spectral RS data and the actual sample data were used to construct SOM estimation model with regression analysis method. The results showed that the characteristic bands of SOM in Landsat8-OLI image were band 5, band 6 and band 7. Based on these three bands, the model forestimating SOM was constructed (R²= 0.704, P<0.001). Through precision analysis of actual measured points (RMSE=8.66) and previous study results (RMSE = 8.85), this model was proved with high precision and strong stability. This study provides not only the technical support for rapid determination SOM over QTP, but also the reference for soil fertility evaluation, carbon pool calculation, soil carbon cycle, crop yield estimation and grassland degradation monitoring in alpine region.

S158.2；TP79

国家自然科学基金项目(41661023)和国家社会科学基金项目(14XMZ072)资助。