Estimations of interblock conductivity and darcian means in unsaturated flow

For the soils described by the Gardner-Russo retention function,the differences between standard estimations of interblock conductivity and the dimensionless horizontal Darcian means(k^*_H are symmetrical but those of k^*_H approaches k^*_V only when both △x and are small enough Therefore,it is rather essential to adopt Darcian means instead of the standard estimation of the unsaturated flow simulation.