摘要
利用AMSR-E观测的土壤表层亮温资料,采用简化修正的单通道算法模型(Single Channel Algorithm,SCA),反演青藏高原地区夏季2011年6-8月的表层土壤湿度。为对比验证反演结果,利用高原东部和中部的玛曲观测网和那曲观测网CTP-SMTMN(Soil Moisture and Temperature Monitoring Netw ork on the central Tibetan Plateau)的土壤湿度观测数据,以及NASA和VUA-NASA两种均基于AM SR-E的反演土壤湿度产品进行验证。结果表明:(1)与VUA-NASA产品和修改后的SCA模型反演结果相比,NASA产品在像元和区域尺度上相关系数较低,MAE(Mean Absolute Error)和RMSE(Root M ean Square Error)较高,明显低估了两个地区的土壤湿度。(2)VUA-NASA产品在玛曲地区表现良好,在那曲地区虽然相关系数较高,但MAE和RMSE同样较高,导致精度较差。(3)对比其他两种产品,修改后的SCA模型反演结果在两个地区表现出较高的相关系数(接近0.800)、较低的MAE(接近0.050m^3·m^(-3))和RMSE(接近0.060 m^3·m^(-3)),有着较高的精度。因此,可以认为修改后的SCA模型可以应用于青藏高原地区土壤湿度动态监测,为研究青藏高原地区的天气和气候变化影响及水循环过程提供了参考和借鉴。
Utilizing AM SR-E brightness temperature data,we adopted a simplified and modified Single Channel Algorithm model（ SCA） to estimate the surface soil moisture（ SM） of the Qinghai-Xizang Plateau from June to July 2011. To validate and contrast the retrievals,we used two kinds of soil moisture products based on AM SRE from NASA and VUA-NASA,and in-situ SM data from M aqu network and CTP-SM TM N（ Soil M oisture and Temperature M onitoring Network on the central Qinghai-Xizang Plateau,hereafter called Naqu network）. The results indicated that：（ 1） Compared VUA-NASA products with SM retrievals by modified SCA model,the NASA product has a higher MAE（ M ean Absolute Error）,RMSE（ Root M ean Square Error） and a lower correlation coefficient both in pixels and areas,apparently underestimating the SM of the two areas.（ 2） VUA-NASA product has a good performance in M aqu area,while in Naqu area it has a high correlation coefficient but relatively large MAE and RMSE resulting in a worse precision.（ 3） In contrast to other two products,modified SCA model has a better accuracy in two areas and provides reliable information on surface SM temporal variability with the lowMAE（ about 0. 050 m3·m-3）,RMSE（ about 0. 060 m3·m-3） and high correlation coefficient（ about 0. 800）. We conclude that the modified SCA model can be applied to SM monitoring in the Qinghai-Xizang Plateau,and offer a good reference to study of climate and weather changes as well as hydrological cycle in the Qinghai-Xizang Plateau.
出处
《高原气象》
CSCD
北大核心
2017年第1期67-78,共12页
Plateau Meteorology
基金
国家自然科学基金面上项目(41275033)
国家自然科学基金青年科学基金项目(41305076)
关键词
青藏高原
土壤湿度
AMSR-E
单通道算法
The Qinghai-Xizang Plateau
Soil Moisture
AMSR-E
Single Channel Algorithm
