A novel frequency-domain integrated sensor for in-situ estimating unsaturated soil hydraulic conductivity
A novel frequency-domain integrated sensor for in-situ estimating unsaturated soil hydraulic conductivity
复制标题
一种新型频域集成传感器，用于原位估算非饱和土导水率
DOI：
10.1016/j.jhydrol.2022.127939
复制
发表时间：
2022-05
影响因子：
6.4
通讯作者：
Qiang Cheng
中科院分区：
文献类型：
--
作者：
Qiang Xu;Yufan Zhu;Yang Xiang;Song Yu;Zhongyi Wang;Xiaofei Yan;Taisheng Du;Qiang Cheng
·设计一种新的集成传感器来测量土壤水势和含水量。·新传感器成本低，降低了传感器之间的不确定性。·新型传感器与理查兹方程相结合，原位估计Ku。·通过两个土壤水力学模型的计算验证了现场估计的Ku。·将传感器与理查兹方程相结合的方法应用于现场。非饱和土壤导水率在农业、水文和生态等方面具有重要的应用价值。现有的土壤导水率测量技术存在不能原位连续测量、成本高或破坏土壤结构等问题。本文设计了一种新型的频域集成传感器，结合理查兹方程，对Ku进行了现场测量。该传感器由3个同轴穿孔圆柱探头（PCC-1、PCC-2、PCC-3）和一根不锈钢针组成，分别测量上层（PCC-1）、中层（PCC-2）和底层（PCC-3）的土壤水势和中层的土壤含水量。在传感器标定后，对桑迪壤土和粘壤土进行了干燥试验。在一定的假设条件下，利用理查兹方程，结合有限差分法和传感器的测量值，在线估计Ku的动态特性，不需要附加参数和边界条件。为了评估现场估算的Ku值的准确性，在实验室中使用货车Anchhten和坎贝尔水力模型作为参考来确定实际Ku值。然后，在一个实验农场进行了田间试验，以测试新的集成传感器的性能。结果表明，现场估算的非饱和区Ku值与室内模型计算的Ku值吻合较好。砂壤土的RMSE（log 10）分别为0.707 cm h −1（货车van Schchten）和0.426 cm h −1（Campbell），粘壤土分别为0.749 cm h −1（货车van Schchten）和0.587 cm h −1（坎贝尔）。在近饱和范围内，与模型计算的Ku相比，现场估计的Ku有所低估。这可能是由于用于标定的土壤水势传感器（TEROS 21）的精度有限、干燥法对Ku的估算不敏感、结构性大孔隙的影响或近饱和区土壤固有水力特性的不连续性造成的。现场估算的Ku总体趋势与实验室估算的Ku基本一致。实验室实测结果与模型计算结果的一致性验证了新型集成传感器的有效性和可行性，实现了现场Ku的估算。此外，该集成传感器具有成本低、传感器间的不确定性小等优点，在现场应用中具有广阔的应用前景。
• Design a new integrated sensor to measure soil water potentials and water content. • The new sensor is low cost and reduces sensor-to-sensor uncertainties. • The novel sensor is combined with Richards’ equation to in-situ estimate K u. • In-situ estimated K u are validated by calculations from two soil hydraulic models. • The combined method using the sensor and Richards’ equation was applied in field. Unsaturated soil hydraulic conductivity ( K u ) plays a significant role in agricultural, hydrological and ecological applications. However, the existing measurement technologies are failed to consecutively measure soil hydraulic conductivity in-situ, high cost or destructive to soil structure. Here we designed a novel frequency-domain integrated sensor that is combined with Richards’ equation to in-situ estimate K u . The novel sensor has three perforated cylinder coaxial (PCC-1, PCC-2, PCC-3) probes and a stainless steel pin to measure soil water potentials at up (PCC-1), middle (PCC-2) and bottom (PCC-3) layers and soil water content at middle layer, respectively. After sensor calibration, drying experiments were conducted with sandy loam and clay loam. The Richards’ equation was used to in-situ estimate dynamics of K u combining finite difference method with measurements of the novel sensor under certain assumptions, and thus neither additional parameters nor boundary condition was required. In order to assess the accuracy of the in-situ estimated K u , the actual K u were determined in laboratory using van Genuchten and Campbell hydraulic models as references. Then, a field experiment was conducted at an experimental farm to test the performance of the novel integrated sensor. The results showed that the in-situ estimated K u in unsaturated range had a good agreement with the model calculated K u in laboratory. The RMSEs (in log 10 ) were 0.707 cm h −1 (van Genuchten) and 0.426 cm h −1 (Campbell) for sandy loam and 0.749 cm h −1 (van Genuchten) and 0.587 cm h −1 (Campbell) for clay loam. In near-saturated range, the in-situ estimated K u were somewhat underestimated in comparison with the model calculated K u . This may attribute to the limitation of accuracy of soil water potential sensor (TEROS 21) used for calibration, the insensitivity of drying method to the estimation of K u or the effect of structural macropores or discontinuity of soil intrinsic hydraulic characteristics in near-saturated range. The overall trend of in-situ estimated K u in the field is similar to that in laboratory. The consistent between the in-situ estimated and model calculated K u in laboratory verified the availability and feasibility of the novel integrated sensor and the estimation of K u in the field was achieved. In addition, the novel integrated sensor is low cost and reduces sensor-to-sensor uncertainties when multiple sensors were used, which has distinct advantages and potential application under field conditions.
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影响因子：
6.4
作者：
C. Du
通讯作者：
C. Du
使用创新的穿孔圆筒同轴介电传感器监测近地表土壤含水量
影响因子：
6.4
作者：
Chen Chao;Yan Xiaofei;Ma Yihan;Yu Song;Xu Qiang;Grantz David A;Lammers Peter Schulze;Wang Zhongyi;Sun Yurui;Cheng Qiang
通讯作者：
Cheng Qiang
影响因子：
6.4
作者：
B. Latorre;D. Moret‐Fernández
通讯作者：
B. Latorre;D. Moret‐Fernández
DOI：
10.2136/sssaj1996.03615995006000020009x
发表时间：
1996-03-01
影响因子：
2.9
作者：
Hudson, DB;Wierenga, PJ;Hills, RG
通讯作者：
Hills, RG
影响因子：
2.9
作者：
Yurui Sun;Shujuan Ren;T. Ren;B. Minasny
通讯作者：
Yurui Sun;Shujuan Ren;T. Ren;B. Minasny