Estimation of in situ unsaturated soil hydraulic functions from scaled cumulative drainage data
Estimation of in situ unsaturated soil hydraulic functions from scaled cumulative drainage data
复制标题
根据缩放累积排水数据估计原位非饱和土水力函数
DOI：
10.1029/94wr00756
复制
发表时间：
1994
影响因子：
5.4
通讯作者：
W. Wallender
中科院分区：
文献类型：
--
作者：
S. Eching;J. Hopmans;W. Wallender
土壤中水分流动和运移过程的模拟依赖于现场代表性的土壤水力学函数。线性变率的概念结合逆技术被用来估计在原位土壤水力特性在32公顷的领域。测量的累积排水曲线按比例缩放，产生比例因子。随后，排水和水分含量分布的比例参考剖面输入到一个数值模型，优化土壤水分保持和水力传导率曲线的比例理查兹方程的逆解的参考土壤剖面。根据参考曲线和比例因子计算每个位置的现场水力功能。此外，原状土芯取自0.3米和0.6米深的44个位置被用来确定土壤质地，土壤持水性和水力传导性曲线在实验室中使用多步流出技术。这些液压功能缩放使用同步缩放技术。参考领域的水力功能相比，以及从0.6米深的土壤芯确定。原位饱和导水率的变异性比土芯小一个数量级。
Simulation of water flow and transport processes in soils rely on field representative soil hydraulic functions. The linear variability concept in combination with the inverse technique was used to estimate in situ soil hydraulic properties in a 32-ha field. Measured cumulative drainage curves were scaled yielding scaling factors. Subsequently, the drainage and moisture content distribution of the scaled reference profile were input to a numerical model to optimize the soil water retention and hydraulic conductivity curves for the reference soil profile by inverse solution of the scaled Richards equation. Field hydraulic functions for each location were computed from the reference curves and scaling factors. In addition, undisturbed soil cores taken from 0.3-m and 0.6-m depths at 44 locations were used to determine soil texture, and soil water retention and hydraulic conductivity curves in the laboratory using the multistep outflow technique. These hydraulic functions were scaled using the simultaneous scaling technique. The reference field hydraulic functions compared well with those determined from the soil cores taken from the 0.6-m depth. In situ saturated hydraulic conductivity variability was one order of magnitude less than that of the soil cores.