Multi-scale Analysis on NDVI and Topographical Factors of Wuyi Mountain Reserve Area Using Wavelet Method
Qiu Bingwen1*, Su Zanyou1, Chen Chongcheng1 and Bela Markus2
1.Key Laboratory of Spatial Data Mining and Information, Sharing of Ministry of Education, Spatial Information Research Center of Fujian Province, Fuzhou University, Fuzhou 350002, Fujian Province, China
2. University of West Hungary, 8002 Szekesfehervar, P.O.B. 52, Hungary
Abstract: Wuyi Mountain Reserve area is the one of the few reserve Areas for both world biosphere, cultural and natural heritage in China. This paper addresses the scale dependency problem of vegetation-topography relations of Wuyi Mountain Reserve area. The wavelet transform was applied to analyze the multi-scale correlations between Normalized Difference Vegetation Index (NDVI) and several topographic factors (DEM, slope and aspect). The results of wavelet coefficient variograms show that spatial patterns of NDVI and Topographical indicator both exhibit two dominant scales. The fact of nearly synchronous scale domain, especially in small scale domain, suggests that tightly-coupled relationship exists between NDVI and DEM. Results of multi-scale correlation relationships among NDVI and geographical factors suggest that the correlation is scale-dependent, i.e. different scales have different coefficients among the factors. The coefficient values between NDVI and topographical factors are larger in coarser scales than those in finer scales, . which suggest that topographical factors have important roles on controlling NDVI patterns in larger scale. The relationship between NDVI and slope, aspect exhibit complicated variation with spatial scales. This study may improve the understanding of the multi- scale role that topography plays in the formation of vegetation patterns in mountainous areas and also suggest that wavelet transform is useful in exploring the multi-scale pattern of natural resources.
Key words: Wuyi Mountain Reserve area; multi-scale analysis; NDVI; DEM