地理系统非均质空间扩散定量研究

QUANTITATIVE ANALYSIS ON NONHOMOGENEOS SPATIAL DIFFUSION IN GEO-SYSTEM

地理系统的复杂性，导致不同地域地理环境存在差异，革新空间扩散的过程与行为将受控于地域的非物质性，从而在均质条件基础上的扩散模型与实际情况有较大出入。本文从非均质空间来考虑，将革新在客观现实中的二维平面运动转换为沿平面方向与地域自然、社会和经济综合质量方向的三维随机运动，由此总结出非均质空间条件下，革新的各向同性、各向异性、多源及动态扩散方程式。

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.