提出一种无需异源数据支持就能有效消除山区地形影响的地形调节植被指数(TAVI).以LandsatTM影像为数据源,采用TAVI进行复杂地形山区植被覆盖度遥感监测;并选择典型样区进行植被指数与太阳入射角余弦值cosi回归分析、比较,定量验证地形调节植被指数抗地形影响的效果.结果表明,TAVI与cosi一元线性回归方程斜率仅为0.01,相关系数只有0.01,TAVI获得预期的抗地形影响的效果;利用TAVI反演的植被覆盖度空间分布呈面状展开,没有出现地形纹理状的分布形态,获得了满意的抗地形影响的效果.
The vegetation monitoring accuracy with conventional vegetation index (VI) is always disturbed by the topographic effect in rugged area. Meanwhile, the application of topographic correction method are limited by the support of high resolution digital elevation model (DEM) data and the matching accuracy between the remote sensing image and DEM data. Therefore, a novel topography - adjusted vegetation index (TAVI) is proposed to eliminate the topographic effect in rugged terrain, which is only based on infrared and red wavebands data of optical remote sensing image. The Landsat TM image is chosen in the rugged terrain to retrieve the vegetation fraction with TAVI. And the TAVI is validated by the regression analysis with the solar incidence cosine and the contrast analysis with NDVL The validation results show that TAVI can diminish the topographic effect remarkably, and the slope of linear regression equation of TAVI and the solar incidence cosine is only 0.01, correlation coefficient of them is only 0.01 either. Accordingly, the vegetation fraction obtains the flat distribution with effectively elimination of topographic effect.