浑善达克地区典型植被NDVI与温度、降水的相关性分析

Correlation Analysis on Typical Vegetation NDVI with Temperature and Precipitation in Otintag Sandy Land

浑善达克沙地处于中国陆地生态系统对全球变化响应的一级敏感区,植被对气候变化敏感。基于1998-2010年SPOT/VEGETATION VGT-S10逐旬NDVI数据,研究区域典型植被的旬归一化植被指数(NDVI)动态变化及其与温度、降水的相关性以及气象因子影响的滞后效应。结果表明,长时间旬NDVI序列较好地反映了主要植被类型随着季节变化的生长发育状况;生长季节内植被旬NDVI和气温的相关性高于其与降水的相关性,气温、降水对不同植被的影响具有滞后效应,滞后期均在40 d以内,滞后期长短因植被而异;年际间旬NDVI与降雨量、温度的相关分析表明在植被快速生长期降雨量对植被生长有重要促进作用,而温度在植被生长初期和成熟期则是植被旬NDVI提高的重要原因;由于春、冬季旬ND-VI与温度、降水变化的高度一致性,全年旬NDVI与气象因子相关分析的可靠性降低;而生长季节内植被旬NDVI与降水、温度的相关性分析可以很好地揭示气象因子与植被生长发育的关系。

Otintag sandy land locates in the terrestrial ecosystem sensitive to global change,where vegetation is sensitive to climate change in China.Using normalized difference vegetation index(NDVI) dataset derived from SPOT/VEGETATION VGT-S10 from 1998 to 2010,the NDVI changes of typical vegetations in the study area and the correlation between NDVI and temperature,precipitation and other meteorological factors at five stations were analyzed.The results showed that long time series NDVI data described the growing and development of the five types of vegetations.Compared with precipitation,temperature was highly positively correlated with NDVI.The lag effects,shorter than 40 days,of temperature and precipitation on NDVI depended on vegetation types.Analysis on inter-annual dataset showed that precipitation in plant fast growth stage stimulated NDVI increase,and that higher temperature in the early and late growth stages kept higher NDVI.The correlation analysis between NDVI and temperature or precipitation during plant growing period from May to September well described their relationships.