中国东部沿海地区暴雨对植被活动的影响

构建1982~2015年的长时间序列NDVI（Normalized Difference Vegetation Index）数据集和收集190 个地面气象站点的降雨数据,运用空间数理统计方法在像元尺度上分析34 a来中国东部沿海地区暴雨灾害发生频率的变化与NDVI变化之间的关系。结果表明：1982~2015年中国东部沿海地区暴雨发生频率在0~13次/a,平均为2次/a。1982~2015年中国东部沿海地区总的暴雨发生次数在逐渐增加,主要集中在夏季。1982~2015年中国东部沿海地区NDVI均值为0.54,植被总体生长状态良好。NDVI分布呈明显的南高北低的空间特征,且总体表现为增加趋势,平均增加0.002/10a。1982~2015年中国东部沿海地区夏季暴雨灾害对NDVI具有明显的抑制作用。总体来看,暴雨灾害发生频率每增加1%,研究区植被NDVI将降低0.01%,但空间上表现为苏北和山东地区显著的抑制性,而河北与广东和广西北部表现为显著的促进作用。

Effect of Rainstorms on Vegetation Activities in Eastern Coastal Area of China

Within the context of global climate change, rainstorm has become one of the important factors restricting plant growth. In this study, the NDVI and meteorological dataset (GIMMS-NDVI and daily precipitation, temperature and radiation) in eastern China from 1982 to 2015 have been obtained to explore the relationships between rainstorm frequency anomaly and NDVI changes. The results show that rainstorm frequency of the study area varies from 0 to 13 times per year during the study period, with a mean value of 2 times per year. In addition, summer rainstorm frequency tends to increase gradually. The mean of NDVI values in the study area is 0.54, which show a clear spatial pattern. Furthermore, the NDVI values in the southern part of study area are generally higher than that in the northern part. However, the slope of NDVI values of the whole region show a rising trend, with an increase of 0.002/10a. The mean of partial correlation coefficients and multiple regression coefficients between rainstorm frequency anomaly and the NDVI variations are -0.02 and -0.01 respectively, representing that rainstorms have a significant negative effect on vegetation activities. In general, the NDVI in the study area will decrease by 0.01% with an increase of 1% of rainstorm frequency. Spatially, the significantly negative effect of rainstorms has been found in northern Jiangsu and Shandong Provinces. However, in Hebei, Guangdong and northern Guangxi Provinces, a significantly positive effect of rainstorm has been observed.