正蓝旗植被覆盖动态变化的遥感监测

 为揭示浑善达克沙地植被变化规律,基于NDVI和植被覆盖度像元分解模型,建立了TM影像尺度下的正蓝旗植被覆盖度遥感定量模型,在此基础上,研究正蓝旗1987和2001年2个时期植被覆盖的动态变化。结果表明: 正蓝旗植被覆盖以中等盖度植被和高盖度植被为主,1987年二者面积占总面积的92．98%,2001年占总面积的77．34％。期间,高盖度植被大幅减少,减少达57．53％,低盖度植被和农田植被面积均显著增加,全旗植被覆盖类型变化以植被退化为主,占发生覆盖类型变化面积的84．53％,这说明正蓝旗的植被生态趋于进一步恶化。

Monitoring Remote Sensing of dynamic change of vegetation coverage in Zhenglan Banner

To reveal the variation law of Otindag sand vegetation, remote sensing quantitative model of vegetation coverage in the Zhenglan Banner under TM is images established based on NDVI and a sub-pixel vegetation coverage model. The dynamic variation of vegetation coverage in Zhenglan Banner in 1987 and 2001 are studied on the basis of above approaches, and the results indicate that the vegetation coverage in Zhenglan Banner mainly has been made up of the medium and high cover degree vegetation which accounted for 94.46% of the total land area in 1987 and 88.92% in 2001. The area of high cover degree vegetation has decreased by 45.92% heavily while the area of low cover degree vegetation and farmland has remarkably increased from 1987 to 2001. The transformation of vegetation coverage type focuses on vegetation degrading, which is 85.17 % of the area that has experienced the transformation of vegetation coverage type. The tendency of vegetation cover transformation in Zhenglan Banner speaks serious deterioration of its ecological environment .