Soil Hydraulic Parameters of Bare Soil Plots with Different Soil Structure Inversely Derived from L‐Band Brightness Temperatures
Soil Hydraulic Parameters of Bare Soil Plots with Different Soil Structure Inversely Derived from L‐Band Brightness Temperatures
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DOI：
10.2136/vzj2014.09.0133
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发表时间：
2015-08
影响因子：
2.8
通讯作者：
M. Dimitrov;J. Vanderborght;K. Kostov;B. Debecker;P. Schulze Lammers;L. Damerow;H. Vereecken
中科院分区：
文献类型：
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作者：
M. Dimitrov;J. Vanderborght;K. Kostov;B. Debecker;P. Schulze Lammers;L. Damerow;H. Vereecken
耕作措施对土壤表层结构有很大影响，对表层土壤水力性质和土壤水分动态有重要影响。在这项研究中，我们在四个28d的周期内，对不同表层结构的裸露粉壤土样进行了L波段亮温和红外(IR)温度的监测。样地间L波段亮温绝对值和归一化亮温的差异表明，利用辐射传输、粗糙度校正和土壤水文模型可以从L波段亮温反演样地比粗糙度、土壤水分含量和土壤水力性质。反算得到的表面粗糙度参数与激光轮廓仪测量得到的表面粗糙度参数吻合较好。在负压水头较大的情况下，耕作地和苗床地的饱和含水率估计值大于压实地，非饱和导水率小于压实地。这些水力特性的差异转化为耕作和苗床小区在28天的测量期内模拟土壤水分的动态大于压实小区。这种差异可以通过现场土壤水分测量定性地证实，但不能定量地证实。此外，通过观测到的红外温度的差异，证实了两个地块之间模拟的实际蒸发速率的差异。结果表明，土壤管理对土壤表面粗糙度和土壤水力性质的影响可以从L波段亮温中推断出来。
The structure of the surface layer of the soil is strongly influenced by soil tillage practices, with important consequences for the hydraulic properties and soil moisture dynamics in the top soil layer. In this study, during four 28‐d periods, we monitored L‐band brightness temperatures and infrared (IR) temperatures over bare silt loam soil plots with different soil surface structure: tilled, seedbed, and compacted plots. Differences in absolute and normalized L‐band brightness temperatures between the plots indicated that plot specific roughness, soil moisture contents, and soil hydraulic properties might be inverted from L‐band brightness temperatures using a coupled radiative transfer, roughness correction, and soil hydrological model. The inversely estimated surface roughness parameters compared well with those derived from laser profiler measurements. The estimated saturated water contents of the tilled and seedbed plots were larger than the one of the compacted plot, and the unsaturated hydraulic conductivity was smaller in the former plots than in the compacted plot for more negative pressure heads. These differences in hydraulic properties translated into larger dynamics of the simulated soil moisture during a 28‐d measurement period in the tilled and seedbed plots than in the compacted plot. This difference could be confirmed qualitatively but not quantitatively by in situ soil moisture measurements. Furthermore, differences in simulated actual evaporation rates between the plots were confirmed by observed differences in measured IR temperatures. The results indicate that effects of soil management on soil surface roughness and soil hydraulic properties could be inferred from L‐band brightness temperatures.