Clue-s and its application for simulating temporal and spatial change of land use in Naiman Banner

Modeling is an important tool for studying land-use change due to its ability to inte grate measurements of changes in land -cover and the associated drivers.Based on an investigation of the existing land use change models,the authors use a model,CLUE-S,which can be applied to simulate land use change at regional extent.It is based on system theory to allow the in tegrated analysis of land use change in relation to socio-economic and biophysical driving factors.Most importantly,the characteristics of land use systems,such as connectivity,hierarchical organiza tion,competition,stability,resilience and so on,are almost completely included in CLUE-S that make it being capable of simulating different land use types simultaneously due to the explicit atten tion to the functioning of the land use system as a whole.To illustrate the functioning of CLUE-S and its validation,an application in Naiman Banner is presented in this paper.As one of the typical counties in Horqin Sandy Land of Inner Mongolia,great land use changes have taken place in Naiman over the past decades.Among those changes,the decrease of grassland,expansion of farmland and reforestation were the most important.The purpose of this case study is to simulate land use change over the past15years by CLUE-S using1985land use maps.Then CLUE-S's simulation results are compared with maps of the actual distribution of land use in2000for validation.The results indicate that CLUE-S is capable of classifying correctly85%of the grid cells into four categories:cultivated land and settlement (including villages and towns),forest,grassland,unused land and waters.Kappa equals0.80in the simulation at the basic grid level(500m×500m).Although the simulation is successful as a whole,the poor simula tion for forest can be found obviously.This failure is mostly caused by the lack of policy in the specification of the land use model.In fact,large amount of forest found recently in northern Naiman was planted guided by the policy of ecological protection.So special attention should be paid to policy factors in the future applications of CLUE-S.