BIMODAL POROSITY AND UNSATURATED HYDRAULIC CONDUCTIVITY
BIMODAL POROSITY AND UNSATURATED HYDRAULIC CONDUCTIVITY
复制标题
双峰孔隙率和不饱和水力传导率
DOI：
10.1097/00010694-199109000-00001
复制
发表时间：
1991
期刊：
影响因子：
--
通讯作者：
M. Kutílek
中科院分区：
文献类型：
--
作者：
H. Othmer;B. Diekkrüger;M. Kutílek
利用室内原状土样测定的土壤水分特征曲线，计算了非饱和导水函数K（h）。将计算的K（h）与现场直接测量的非饱和电导率数据进行比较。当土壤水分特征曲线按货车法平滑，K（h）按Mualem法计算时，两种方法计算结果的一致性较差。当三次样条用于保水数据时，导出的孔径分布曲线显示出两个峰。在双峰多孔系统的假设下，计算了每个孔子系统的K（h）。整个多孔系统的函数K（h）由两部分组成，一部分接近饱和，第二部分为中等湿度的土壤。在K（h）的两个分量的交点处存在奇点。由此计算的K（h）与直接测量的K数据之间的一致性得到了改善。因此，证实了土壤毛细孔隙系统范围内存在双峰孔隙度的假设，并证明了这两个子系统在土壤中检测时的实际重要性。
Soil water characteristic curves determined on undisturbed soil samples in the laboratory were used for the calculation of the unsaturated conductivity function K(h). This computed K(h) was compared to the unsaturated conductivity data measured directly in the field. When the soil water characteristic curve was smoothed according to the van Genuchten procedure and K(h) was evaluated according to Mualem's approach, the coincidence of results of both procedures was poor. When a cubic spline was used for the water retention data, the derived pore size distribution curve showed two peaks. With the assumption on a bimodal porous system, K(h) was computed for each of the subsystem of pores. The function K(h) of the whole porous system is then composed of two parts, one valid close to saturation, the second for medium wetness of the soil. At the intersection of both components of K(h) a singularity exists. The agreement between the K(h) so computed and the directly measured K data has been improved. The hypothesis on the existence of the bimodal porosity within the range of the capillary soil porous system has been therefore confirmed together with the proof on the practical importance of both subsystems when they are detected in the soil.