Abstract:

The regional vegetation is severely influenced with the global climate change and rapid urbanization. The NDVI (normal differentiation vegetation index) was applied as the indicator to present the vegetation pattern and dynamics in Tangshan, a rapidly-urbanized area, in order to study the vegetation distribution and dynamics. The result showed that NDVI had an increasing tendency from 1979 to 2009, and was more and more polarized. The NDVI apparently reduced in Zunhua, Qianxi, Qian'an, Tanghai and the city center during the past three decades. In the northern mountainous area, the reduction of the NDVI became severer, the NDVI patches were further fragmented, and the fragmented patches had a trend to spread out and connect each other, compared to the southern coastal area. It was also found that the urban development direction and the land use pattern, especially the construction of roads, were the underlying factors that led to this vegetation pattern. Based on all of the above, the vegetation restoration in Tangshan should be in line with situation in every region, namely, in the northern mountainous area, the original vegetation should be preserved, and it is necessary to afforest the mines and make the town planning. The central urban area needs to accelerate the construction of urban forests, the agriculture shelter forest needs to be planted in the middle and the rural area. In the southern coastal region, the coastal windbreak and the protection forests should be constructed.

Key words: NDVI, dynamics, land use, Tangshan