Preliminary Investigation of the Spatial Variability of Soil Properties
Lei Zhidong Yang Shixiu (Tsinghua University)Xu Zhirong (General Station of Environmental Hydrogeology, Henan Province)G. Vachaud(Institut de Mecanique, Grenoble, France)
Considering the importance and worthful application for the treatment of field observation, this paper deals with the spatial variability of soil properties, based on the data of the field .experiment with a view toward developing techniques.In order to characterize the experimental site, the fellowing different series of measurement have been done:(1)a first set of 135 undisturbed samples (silt and clay fraction, bulk density); (2)a second set of 35 undisturbed samples (soil texture, saturated hydraulic conductivity, etc.); (3)a series of 35 tensiometers;(4)12 infiltration test. Then probability analysis with classical statistical methods have been carried out. The Sample number were determined within a given uncertainty at a known confidence level. Using semivariogram and autocorrelation, the spatialstucture of soil properties were checked-----about the directionality andthe range of correlation. As an example of application of semivariogram, an optimal interpolation with Kriging has been calculated.Based on the information of infiltration, the evaluation of the validity of the infiltration equation, the spatial analysis of infiltration and its parameters have been discussed roughly.