Variation of Normalized Difference Vegetation Index (NDVI) and its response to extreme climate in the coastal area of China during 1982-2014

Based on GIMMS NDVI3g dataset, the spatial- temporal dynamics of Normalized Difference Vegetation Index (NDVI) during growing season in the coastal area of China from 1982 to 2014 was explored. Additionally, the response of NDVI to extreme temperature events and extreme precipitation events at annual as well as monthly scale was further estimated at the regional scale of meteorological stations. Results showed that NDVI in the coastal area of China and its sub- regions all presented an upward trend during the past 33 years, and the increasing tendency would be continue in the future. NDVI in the sub- regions to south of Jiangnan (inclusive) coastal area was much higher than that to north; however, a significant decreasing trend of NDVI during 1982- 2014 was found in the Yangtze River delta and the Pearl River delta, which were both located in the southern coastal area, and a general increasing trend was detected in the sub-regions to north of Jiangnan coastal area. NDVI was negatively correlated with the warm extremes (Warm days and Maximum value of daily maximum temperature) in the west of Dongbei coastal area, and sub- regions of Huabei and Huanghuai coastal areas, but was showing a positive correlation in the other sub- region coastal areas. A negative correlation was found between NDVI and the cold extremes (Cool days and Minimum value of daily minimum temperature) in the coastal area of China, where vegetation growth showed a lagging effect to cold extremes. NDVI generally had positive correlation with diurnal temperature range (DTR) in the sub-regions to south of Jianghuai (inclusive) coastal area but was negatively correlated with diurnal temperature range to north. There was a positive correlation between NDVI and extreme precipitation indices (Maximum 1- day precipitation amounts and Maximum 5-day precipitation amounts) in the sub-regions to north of Huanghuai coastal area, but a negative correlation in the sub-regions to south, as well as in the middle east of Dongbei coastal area. Moreover, an obviously lagged correlation between NDVI and extreme precipitation indices was also found in the sub-regions to north of Huanghuai coastal area