不同空间尺度下的土壤侵蚀元胞自动机建模评述

Review of soil erosion modeling using Cellular Automata in different spatial scales

土壤侵蚀系统是一个典型的非线性动力系统,系统内部的侵蚀发育演化过程十分复杂,为了对该过程进行精确的模拟和预测,需要发展有效的技术和方法。元胞自动机(cellular automata,CA)是一种具有时空特征的离散动力学模型,采用"自下而上"的构模方式,对于模拟和分析具有空间特征的土壤侵蚀系统具有先天优势。由于空间尺度变化所引起的土壤侵蚀因子对侵蚀产沙过程的影响不同,CA模型在坡面尺度下主要针对细沟侵蚀和土壤颗粒的变化,在小流域尺度下涉及到更多的元胞状态和更加完整的侵蚀过程,在大区域尺度下重点研究气候和地貌之间的相互作用。不同空间尺度建立的CA模型没有确定的转换规则,模型通用性较低,今后需要在三维可视化、智能化等方面深入研究CA模型在土壤侵蚀领域的应用。

Soil erosion system is a typical nonlinear dynamic system, in the inner of which the erosion development and evolution is very complex and require effective technology and method to simulate and predict the process accurately. And the cellular automatic is a kind of discrete dynamics model with temporal and spatial features, which uses the method of bottom up and can be suitable to application in the time space evolution of soil erosion, for its inherent advantages in simulation and analysis the soil erosion system with spatial features. Then in the study of time-space evolution of soil erosion, the variation of spatial scales can cause that the erosion factors have different effects on the process of soil erosion. Therefore in the construction of CA model, in slope scale the main research is rill erosion and the change of soil particles, in small watershed scale the CA model includes more cell states and more complete erosion process, in region scale the CA focuses on interaction of the climate and topography.Because of no unified conversion rule in different scales, the CA model with low generality need three- dimensional visualization, automatically adjusting parameters with the method of data mining and modeling the intelligent CA simulating expert systems.