Three-Dimensional Visualization of Soil Electrical Conductivity Variation by VRML

High quality three-dimensional (3-D) earth data is very important for environmental assessment studies, precision agriculture and water quality simulation modeling. In the present study, the soil apparent electrical conductivity (ECa) inversed by the EM38 linear model from aboveground EM38 measurements were selected as the data source of 3-D spatial variability. Firstly, the sphere model which built by VRML approach was used to present the 3-D distributed ECa sites. Then, the plume model was built with the help of EVS, which presents soil volume of ECa greater than a certain value. The VRML models presented a superior visualization of spatial distribution of ECa in 3-D space that 2-D interpolation can’t achieve. It was shown that the field in the east corner and low salinity level in the west and northern corner of the field has a high salinity level. The salinity increased with the increase of the soil depth at the vertical direction. At last, the vrml models were placed on a WWW server, which can be opened and accessed by anyone. Using WWW to transfer information to the public is considered as a very important and practical method.