丹江口库区土地利用结构与格局优化

Optimization of Land Use Structure and Spatial Pattern for the Danjiangkou Reservoir Area

丹江口库区作为南水北调中线工程的水源区,其生态环境状况和水质安全不仅关系到库区的社会经济和环境保护的协调发展,也决定着调水工程的成败。科学量化评价丹江口库区土地利用结构并进行格局优化,对于库区可持续发展有着重要的意义。利用丹江口库区1990年、2000年、2007年TM遥感数据,在RS和GIS技术的支持下,在综合使用马尔柯夫预测模型和元胞自动机方法的基础上,建立了土地利用格局优化模拟模型,进行了丹江口库区生态安全条件下的土地利用格局优化模拟研究。通过马尔柯夫预测模型得出各土地利用总量预测结果,以宏观用地总量需求和微观土地供给相平衡为原则,利用具有复杂空间演变能力的元胞自动机完成土地空间分配。结果表明:1990—2007年期间,丹江口库区土地利用类型的面积发生了很大变化,其中主要以农田面积大幅度减少和林地、灌丛以及居民地面积的大幅度增加为主。在未来的2020年,经格局优化,农田、未利用地面积显著减少,林地、园地面积相应增加,生态环境状况良性发展。结果显示使用CA-Markov模型进行土地利用变化预测,充分利用CA模型模拟复杂系统空间变化的能力和Markov模型长期预测的优势,对于揭示土地利用变化的动态机制具有一定意义。

The Danjiangkou reservoir lies in the upper Hanjiang Basin and is the source of water for the Middle Route Project（MRP） under the South-to-North Water Transfer Scheme（SNWT） in China.The situation of eco-environment and the water quality security of the Danjiangkou Reservoir Area（DRA） play important roles in local coordinated development of economic and social development and environmental protection and would determine whether the MRP will succeed or not.The scientific and quantitative assessment and optimization of land use structure and spatial pattern is significant to the sustainable development of the DRA.This study aimed to predict land-use change trend of Danjiangkou reservoir area in 2020 by Markov prediction model and cellular automata model,in the support of the RS and GIS and based on the TM remote sensing data of Danjiangkou reservoir area during 1990 and 2007.The predicted results of the land use amount are acquired dynamically by the Markov prediction model,and with the total land of demand from a macroscopic viewpoint and the dynamic balance of land supply from a microscopic viewpoint as the principle,the distribution of land-use is achieved by Cellular Automata model.The results showed that in the period of these seventeen years from 1990 to 2007,great changes have taken place on the land use types in the study area,which was mainly characterized as the greatly increased forest,shrub and residential area and the greatly decreased farmland.In the 2020,by optimal allocation,the area of the croplands and unutilized land decrease rapidly,and the proportion of the forest land area and garden area increase accordingly,which healthily promote the development of eco-environment.The results showed that CA-Markov model make the fullest use of the simulating capability to space changes of complex system of CA model and the advantage of long-term prediction of Markov model,which would provide an important reference to reveal the dynamic mechanism of land-use change.