Abstract: Interaction of environmental management between groundwater and surface water is getting more and more important.An accurate and fast method to estimate the hydraulic permeability is the key of scientific management.In environmental management and planning，problems foced by managers in large scale.In the scale of a dozen even dozens of kilometers，original Kriging is way too complex to apply.This research was focused on simplify the Kriging under the principle of feasibility and flexibility.A risk estimation was deduced from the improved method.