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农田蒸散双层模型及其在干旱遥感监测中的应用 被引量:99
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作者 隋洪智 田国良 李付琴 《遥感学报》 EI CSCD 1997年第3期220-224,共5页
该文建立了在部分植被条件下估算农田蒸散的双层模型,利用此模型和NOAA-AVHRR数据对黄淮海平原春季旱情进行了评估,并做出了干旱及蒸散分布图。对双层模型和单层模型的估算结果进行了比较,结果表明在部分植被条件下双层模型估算的精度... 该文建立了在部分植被条件下估算农田蒸散的双层模型,利用此模型和NOAA-AVHRR数据对黄淮海平原春季旱情进行了评估,并做出了干旱及蒸散分布图。对双层模型和单层模型的估算结果进行了比较,结果表明在部分植被条件下双层模型估算的精度要高。 展开更多
关键词 双层模型 干旱 半植被覆盖 农田 蒸散 遥感
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A new semi-empirical model for soil moisture content retrieval by ASAR and TM data in vegetation-covered areas 被引量:8
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作者 YU Fan ZHAO YingShi 《Science China Earth Sciences》 SCIE EI CAS 2011年第12期1955-1964,共10页
Active microwave and passive optical remote sensing data have demonstrated their respective advantages in inversion of surface soil moisture content. A new semi-empirical model is presented for soil moisture content r... Active microwave and passive optical remote sensing data have demonstrated their respective advantages in inversion of surface soil moisture content. A new semi-empirical model is presented for soil moisture content retrieval in vegetation-covered areas, using ENVISAT-ASAR and LANDSAT-TM data collaboratively. Derivation of the algorithm is based on simplification of the Michigan Microwave Canopy Scattering Model (MIMICS). In the model, the ground surface is divided into a canopy layer and a soil layer, and empirical relationships simulated among vegetation water mass We, the backscatter coefficient σpq1, the bidirectional scattering coefficient σpq2 and the extinction coefficient τp. The key input parameters of the semi-empirical model are reduced to only the leaf area index (LAI), which can be easily inverted by the optical model PROSAIL, allowing coupling of the microwave and optical models to be achieved. Also, vegetation RMS height (Svcg) is introduced to correct for the radar-shadow effect caused by over-laying vegetation. Analysis of the parameter sensitivity of the semi-empirical model showed that when the regional Leaf Area Index is small (LAI≤3), the model is more applicable. Soil moisture distribution in the study area was mapped using the semi-empirical model and field ground measurements used for model validation. This showed that, after correction of the radar-shadow effect, the average relative error (Er) between ground-measured and semi-empirical model-derived estimates of soil moisture decreased from 17.6% to 10.4%, while the RMS reduced from 0.055 to 0.031 g cm^-3. The accuracy of soil moisture estimates from the semi-empirical model is much better than for the MIMICS model (Er = 22.7%, RMS = 0.068 g cm^-3), showing that the semi-empirical model is efficient at obtaining regional surface soil moisture contents when LAI is small. 展开更多
关键词 microwave and optic remote sensing MIMICS PROSAIL soil moisture
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