Interaction of Land Demand and Supply Effects in Intensive Land Use: a Simulation Study for Chengdu,China

Intensive land use( ILU) policies affect the demand and supply of land. These policies promote efficient land use, and demands for land must therefore be evaluated in terms of the level of land-use intensity. If the demand is considered excessive, ILU policies act like a "valve"to restrict the land supply. Drawing on data from Chengdu,China,where developable land is scarce,we construct a model using system dynamics( SD) to simulate two scenarios: ILU development and non-ILU development. The results show that when ILU leads to positive land-use efficiency,land supply will exceed demand,resulting in an appropriate level of real demand for the current population level and GDP. Thus,artificial demand( inflated by investors) is reduced. By contrast,when non-ILU leads to negative land-use efficiency,land demand will exceed supply. In this scenario,artificial demand is higher than real demand.

Stochastic Approximate Solutions of Stochastic Differential Equations with Random Jump Magnitudes and Non-Lipschitz Coefficients

A class of stochastic differential equations with random jump magnitudes( SDEwRJMs) is investigated. Under nonLipschitz conditions,the convergence of semi-implicit Euler method for SDEwRJMs is studied. The main purpose is to prove that the semi-implicit Euler solutions converge to the true solutions in the mean-square sense. An example is given for illustration.