ANALYSIS ON TEMPORAL-SPATIAL CHANGE OF VEGETATION COVERAGA IN HULUNBUIR STEPPE (2000-2014)

Fraction of vegetation coverage (FVC), an important index to depict the conditions of land covered by vegetation, is increasingly used in monitoring grassland degradation in ecological researches. Hulunbuir Steppe is one of the best grasslands in China. So, in this study, we set Xinbaerhuyouqi, Xinbaerhuzuoqi, Chenbaerhuqi, and Ewenkezuzizhiqi as the study area. Pixel Decomposition Models was introduced to retrieve the vegetation coverage, and the time series of vegetation coverage was reconstructed. Then we analyzed the temporal-spatial changes FVC time series for study region over the 15-year period from 2000 to 2014. The results showed that the higher level vegetation coverage mainly distributed in the east of study area; on the contrary, the lower level of that mainly distributed in the west of study area. The vegetation coverage of whole study area was decreased in the first 10 years, while that was increased slowly in the latter 5 years. Additionally, the break points which occurred in green-up and green-end periods had much more significant correlation with temperature; the break points occurred from July to August correlated with precipitation.National Natural Science Foundation of China [41271346]; Major State Basic Research Development Program of China [2013CB733402]; Open Fund of State Key Laboratory of Remote Sensing Science [OFSLRSS201518]CPCI-S(ISTP)rsfeipeng@163.com; fanwj@pku.edu.cn4514-451