关键词: 非均质空间, 各向同性扩散过程, 各向异性扩散方程, 多源扩散方程, 动态扩散过程

Abstract: The Geo-system is an open and complicated system. This complexity origins from the geographic environment including natural environment and economic environment. However geographic space is a nonhomogeneos space. Furthermore.the nonhomogeneity of regions exists so absolutely that innovation diffusion in geo-system is restricted by geographic environment,as there is a great deal of differences between regions which have different natural,economic and social qualities.Then, there is no doubt that the diffusion process of any innovation is in nonhomogeneos space.Spatial diffusion relates to not only distance but also nonhomogeneity of regions.A significant body of spatial diffusion theory was formed as a result of the work of T.Hagerstrand and others. Spatial diffusion research is of importance in understanding the spread of diseases, ideas,business, products and people from initial origins through time and space. But. existent diffusion models have been found to be parsimonious and inflexible in solving practical problems, because the T.Hagerstrand’s models were based on the homogeneos space and the diffusion of geographic environment was ignored. It is considered that innovation is composed of infinite and noncontinuous small diffusion medium and the third dimension is included in space due to nonhomogeneity in this paper.We transfer the movement of innovation in two-dimensional space into a great deal of random medium movement in three-dimensional space.The random movement may be described by the Kolmogorov diffusion equation. By means of the spatial diffusion equation, we can derive the centers of isotropic diffusion,anisotropic diffusion, multiple diffusion and the dynamic diffusion equation in nonhomogeneos space.

Key words: nonhomogeneos space, isotropic diffusion, anisotropic diffusion, multiple diffusion centers, dynamic diffusion, diffusion equation