山区资源可持续利用模型

ON THE SUSTAINABLE RESOURCES MODEL IN MOUNTAIN AREA

人和自然资源构成了山区人地系统的一个子系统,且是研究后者的很理想的切入点.在人地协同论的基础上,建立了人-资源可持续利用模型.

According to the Man-Earth Synergetics,a sustainable utilization model of renewable natural resources is given.If the man-resource dynamic system is expressed by the differential equation dx/dt = g(x) - u(t)where x = x (t), being resource value in t, is the state variable, u = u (t), being resource utilization rate in t,is the control variable,g(x) is resource renewable rate and can be written in a logistic function, g (x ) = rx (1 - x/k) When the aim is to determine an allowable resource utilization rate u (t),the evaluated x will be a solution of the equation dρ(x) /dx = δ[p - C(x)] where p is the price and C(x) is the cost of resources, δ is discount rate,and p(x) = g(x)[p - C(x)] The sustainable resource utilization model is