Spatiotemporal variability of grassland vegetation cover in a catchment in Inner Mongolia, China, derived from MODIS data products
Spatiotemporal variability of grassland vegetation cover in a catchment in Inner Mongolia, China, derived from MODIS data products
复制标题
DOI：
10.1007/s11104-010-0465-4
复制
发表时间：
2011-03
期刊：
影响因子：
4.9
通讯作者：
D. Schaffrath;F. Barthold;C. Bernhofer
中科院分区：
文献类型：
--
作者：
D. Schaffrath;F. Barthold;C. Bernhofer
半干旱地区植被的条件、分布和发育变化很大。本研究通过分析中分辨率成像光谱仪（MODIS）数据产品，检测了2000年至2008年锡林河流域植被的时空变化。该研究以LAI（叶面积指数）为基础，并以空间分辨率为1公里的NDVI（归一化植被指数）和LST（地表温度）数据为支持。 2000年至2008年流域平均LAI为0.59。研究期间的降水数据决定了流域植被的条件和分布。在干旱年份，例如2001年和2005年，LAI明显低于2003年（LAI = 0.72）（0.52），因为2003年是多雨年。由于降水量总体上从东南向西北减少，LAI值按照该梯度减小。锡林河沿岸地区LAI较低（0.4），重度放牧影响明显。 LAI 的高时间变异性通过其高平均 CV（变异系数）体现出来，在观察年份中为 48%。对样本区域的分析说明了流域内植被发育的时间和空间差异，并显示流域西北部的生长开始普遍延迟。
Conditions, distribution and development of vegetation in semi arid regions are highly variable. In this study we detected the temporal and spatial variability of vegetation in the Xilin river catchment from 2000 to 2008 by analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) data products of that period. The study is based on LAI (Leaf area index) and supported by NDVI (Normalized difference vegetation index) and LST (Land surface temperature) data with a spatial resolution of 1 km. The mean LAI of the catchment from 2000 to 2008 is 0.59. Precipitation data of the study period governs the conditions and distribution of vegetation in the catchment. In dry years, e.g. 2001 and 2005, LAI was clearly lower (0.52) compared to 2003 (LAI = 0.72) which was a wet year. As precipitation generally decreases from south-east to north-west, LAI values decrease according to this gradient. The influence of heavy grazing in the vicinity of the Xilin river is obvious as LAI is low (0.4) in these areas. The high temporal variability of the LAI is displayed by its high mean CV (coefficient of variation) which is 48% for the observed years. The analysis of sample areas illustrates temporal and spatial differences in vegetation development within the catchment and shows a generally delayed growth start in the north-west of the catchment.