1998-2015年北京市NDVI时空变化及其与气候因子的响应关系

Spatial-Temporal Characteristics of NDVI and Its Relationship with Climate Change in Beijing from 1998 to 2015

为了研究植被生长与气候因子的响应关系,利用北京市1998-2015年的SPOT-NDVI数据,采用趋势分析法、偏相关和复相关分析法,并结合北京市的气象数据,在年、季尺度上,分别对NDVI的时空变化特征及其与气候变化的关系进行了分析。结果表明:(1)年尺度上,山区的NDVI大于平原区;北京市植被空间变化率整体上呈增长趋势,中心城区周边的平原区植被空间变化率呈下降趋势;从年际变化分析,植被变化与降水的关系较于气温因素更密切。(2)在季节空间变化尺度上,春季是植被面积区域显著增长的季节;植被的生长在不同季节对水热条件变化的敏感性不同,春、秋季植被生长对于气温的敏感性高于降水;夏季植被的生长对于降水的敏感性更高。(3)当月的植被生长与提前一个月的降水和提前两个月的气温的变化较为密切。研究结果揭示了气候是影响植被分布的重要因子,了解气候的变化规律对于植被的保护具有重要的指导作用。

In order to study the response relationship between vegetation growth and climate factors,we based on the SPOT-NDVI data of Beijing from 1998 to 2015, using the trend analysis method, partial correlation and complex correlation analysis method, combining with the meteorological data of Beijing, we analyzed the relationship climate change with the temporal and spatial variation characteristics of NDVI at the annual and seasonal scales. The results show that:(1) on the annual scale, based on the spatial distribution analysis, the NDVI of the mountainous area is larger than that of the plain area;the spatial change rate of vegetation in Beijing is generally increasing, the spatial change rate of vegetation in the plain area around the central city shows a downward trend;based on the annual variation analysis, the vegetation changes have the closer relationship with precipitation than the temperature factor;(2) on the seasonal scale, the maximum area of spatial significant growth vegetation occurred in spring, the growth of vegetation is different in different seasons;the sensitivity of vegetation growth to temperature is higher than that to precipitation in spring and autumn;the growth of vegetation was more sensitive to precipitation in summer;(3) the vegetation growth of the month is more closely related to the precipitation of previous month and the temperature of previous two months. The results indicated that climate is an important factor affecting the distribution of vegetation, and understanding the law of climate change has an important guiding role for the protection of vegetation.