CLUE-S模型及其在奈曼旗土地利用时空动态变化模拟中的应用

CLUE-S and its application for simulating temporal and spatial change of land use in Naiman Banner

在对目前常用的土地利用变化模型进行调研的基础上,认为CLUE-S模型是众多模型中适用于区域土地利用变化研究的一种较好的模型;它是根据系统论的观点,在深刻理解土地利用系统内土地利用变化特征(包括关联性、竞争性、稳定性以及等级性等)的基础上构建而成,具有同步模拟不同土地利用变化的能力。论文以奈曼旗为例,根据1985年的空间图形数据,结合道路、居民点、城镇、水域的分布、以及地形和土壤等驱动因素,对其2000年的土地利用变化格局进行模拟;并用2000年的土地利用现状图对模拟结果进行检验。结果显示,在基本单元(500m×500m栅格)的水平上,模拟的正确率为85%,Kappa指数值是0.80。说明CLUE-S模型具有成功模拟区域土地利用时空动态变化的能力,是值得向国内同行推荐的一种较好的LUCC模型。

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.