Natural features such as mountain ranges, steep slopes and vegetation prevent human movement from one habitat to another. They prevent the ecological harm from natural phenomenon like erosion and landslide. Forests de...Natural features such as mountain ranges, steep slopes and vegetation prevent human movement from one habitat to another. They prevent the ecological harm from natural phenomenon like erosion and landslide. Forests destruction has brought about deterioration of ecological environment such as increasing soil and water losses. RS （Remote Sensing） and GIS （Geographic Information System） technology have enhanced the eco-environment assessment procedure using eco-environment quality index tool. This paper presents results of the research on the investigation of the potentials of different landscapes on the complex ecosystem of Makeng Village in Fuj Jan Province to act as natural barrier to eco-environmental vulnerability. Vulnerability factors analysed were soil erosion, vegetation cover, land use types, slope and elevation. To see how one factor acts as natural barrier eco-environment stressors, factor maps were overlaid in pairs using ArcGIS 9.2 software and the matrix statistics exported for analysis in Microsoft Excel. The results showed steep slopes naturally limit human activities, growth of big trees and increase soil erosion. Flat and gentle slopes are less vulnerable to erosion. Elevation is among natural barriers to human activities. Human activities decrease with increasing elevation, hence making the eco-environment naturally stable/undisturbed. In this study, eco-vulnerability to erosion decreases with increasing vegetation cover.展开更多
The reliability of a complex system passes through a gradual deterioration until at some critical level, the system fails completely. The study of the exponential stability of such a system requires the application of...The reliability of a complex system passes through a gradual deterioration until at some critical level, the system fails completely. The study of the exponential stability of such a system requires the application of functional analysis and, particularly, the theory of linear operators in Banach space to demonstrate the existence of strictly dominant eigenvalue. Through analyzing the variation of the essential spectral radius of semigroups before and after perturbation, it is shown that the dynamic solution of the system converges to the steady-state solution of the system exponentially under certain condition.展开更多
文摘Natural features such as mountain ranges, steep slopes and vegetation prevent human movement from one habitat to another. They prevent the ecological harm from natural phenomenon like erosion and landslide. Forests destruction has brought about deterioration of ecological environment such as increasing soil and water losses. RS （Remote Sensing） and GIS （Geographic Information System） technology have enhanced the eco-environment assessment procedure using eco-environment quality index tool. This paper presents results of the research on the investigation of the potentials of different landscapes on the complex ecosystem of Makeng Village in Fuj Jan Province to act as natural barrier to eco-environmental vulnerability. Vulnerability factors analysed were soil erosion, vegetation cover, land use types, slope and elevation. To see how one factor acts as natural barrier eco-environment stressors, factor maps were overlaid in pairs using ArcGIS 9.2 software and the matrix statistics exported for analysis in Microsoft Excel. The results showed steep slopes naturally limit human activities, growth of big trees and increase soil erosion. Flat and gentle slopes are less vulnerable to erosion. Elevation is among natural barriers to human activities. Human activities decrease with increasing elevation, hence making the eco-environment naturally stable/undisturbed. In this study, eco-vulnerability to erosion decreases with increasing vegetation cover.
文摘The reliability of a complex system passes through a gradual deterioration until at some critical level, the system fails completely. The study of the exponential stability of such a system requires the application of functional analysis and, particularly, the theory of linear operators in Banach space to demonstrate the existence of strictly dominant eigenvalue. Through analyzing the variation of the essential spectral radius of semigroups before and after perturbation, it is shown that the dynamic solution of the system converges to the steady-state solution of the system exponentially under certain condition.
