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利用2007～2009年的SPOT VEGETION NDVI数据来延长1982～2006年GIMMS(Glob-al Inventory Monitoring and Modeling Studies)NDVI数据,从而得到1982～2009年的NDVI数据,结合同时期的气象资料,利用经验模态分解方法(EMD),对黑河流域季节合成植被指数(SINDVI)、气温以及降水序列的周期性进行了分析,并进一步分析了黑河上中下游NDVI和气温、降水之间的关系。结果表明:上游SINDVI与气温、降水均存在准3a和准6a的相似周期,中游SINDVI与气温存在准3a和准10a的相似周期,而与降水存在准3a、准6a、准8a和准15a的相似周期,下游SINDVI与气温存在准3a和准10a的相似周期,与降水存在准3a和准6a的相似周期。表明在黑河流域,气温和降水均是影响植被变化的重要因子,而气候因子的周期性变化主要受大气运动的影响,进而影响植被的周期变化。因此,EMD方法在分析植被动态的周期性特征及其与气象条件周期性的关系方面具有较好的效果。
The NDVI data of GIMMS (Glob-al Inventory Monitoring and Modeling Studies) from 1982 to 2006 were extended by using SPOT VEGETATION NDVI data from 2007 to 2009 to obtain the NDVI data from 1982 to 2009. Combined with the meteorological data of the same period, State decomposition method (EMD) was used to analyze the seasonal composite vegetation index (SINDVI), temperature and periodicity of precipitation in the Heihe River Basin. The relationship between NDVI and temperature and precipitation in the middle and lower reaches of the Heihe River was further analyzed. The results show that both upstream and downstream of SINDVI have the similar periods of quasi-3a and quasi-6a, while the SINDVI in the middle reaches a similar period of quasi-3a and quasi-tena to the temperature, while the quasi-3a, quasi-6a, quasi- In the similar period, the similar period of quasi-3a and quasi-tena exists in the downstream SINDVI and the temperature, and similar periods of quasi-3a and quasi-6a exist in precipitation. It shows that in the Heihe River Basin, both temperature and precipitation are important factors affecting the vegetation change. The cyclical changes of climatic factors are mainly affected by the atmospheric movement and thus the vegetation cycle changes. Therefore, the EMD method has a good effect in analyzing the periodic characteristics of vegetation dynamics and its periodic relationship with meteorological conditions.