基于遥感与地面实测的青藏高原冻土流域土壤温湿度变化分析

Dynamic Analysis of Soil Temperature and Soil Moisture in the Permafrost Basin of the Qinghai-Tibet Plateau Based on Satellite and Ground Observations

为研究青藏高原冻土流域土壤温湿度变化特征,在唐古拉冻土流域基于多源遥感(SMAP、ESA CCI)监测数据进行表层土壤温湿度的时空分布刻画,基于地面实测站点(唐古拉冻土气象站、DFIR冻土积雪气象站)数据进行不同深度土壤温湿度的动态分析,并进行遥感与地面站点表层土壤温湿度的对比研究。结果表明,唐古拉冻土流域海拔较低处土壤温度高于海拔较高处,流域东部土壤湿度高于西部;土壤温湿度变化随着埋深加深明显滞后,且冻结期土壤湿度呈现出明显的两段式下降趋势;SMAP土壤温湿度数据与地面站点监测数据相关性较好,相比ESA CCI数据,SMAP数据准确度更高。

To obtain the dynamic characteristics of soil in typical permafrost basins of the Qinghai-Tibet Plateau,we characterize the spatiotemporal distribution of surface soil temperature and soil moisture in the Tanggula permafrost region based on multi-source remote sensing(SMAP,ESA CCI)monitoring data.We also analyze the changes of soil temperature and soil moisture at different depths based on ground measurement data from Tanggula permafrost meteorological station and DFIR permafrost snow meteorological station.Our results show that soil temperature is higher at lower altitudes than at higher altitudes in the Tanggula permafrost region,and soil moisture is higher in the eastern part of the region than in the western part.Changes in soil temperature and soil moisture lag significantly behind as depth increases,and soil moisture during freezing periods shows a clear two-stage downward trend.SMAP soil temperature and moisture data are well correlated with ground station monitoring data,and SMAP data are more accurate than ESA CCI data.