Assessing the Impacts of Extreme Precipitation Change on Vegetation Activity

Abstract

Extreme climate events frequently have more severe effects on terrestrial vegetation activity than long-term changes in climate averages. However, changes in extreme climate events as well as their potential risk on vegetation activity are still poorly understood. By using the Middle and Lower Reaches of the Yangtze River (MLR-YR) in China as an example, this paper aims to understand the vegetation response to changes in extreme precipitation events from 1982 to 2012 using the maximum normalized difference vegetation index (NDVI) as an indicator. By applying extreme value theory (EVT), the potential risks of extreme precipitation events on vegetation activity were analyzed by conducting return period analysis. Results indicated that vegetation activity could be affected by extreme precipitation events, especially the combined effects of the frequency and intensity of precipitation extremes. For instance, vegetation activity could be enhanced in the regions with weakened intensity but increased occurrence of extreme precipitation events. In addition, we found potential risk of extreme precipitation events on vegetation activity from the results of precipitation extreme trend and return period analysis. These phenomena can be associated with the local occurrence of extreme precipitation events, different land cover types, and soil moisture cumulative effect on vegetation growth. This study stresses the importance of considering both current changes in and the potential risk of extreme precipitation events to understand their effects on vegetation activity.

Trend Changes of the Vegetation Activity in Northeastern East Asia and the Connections with Extreme Climate Indices

“…Moreover, Tan (2015), Cui (2019), and Felton (2019) found a significant correlation between NDVI and extreme rainfall [38][39][40]. Pei (2021) and Zhao (2018) concluded that increased intensity and frequency of extreme precipitation promoted vegetation growth [11,41]. In the present study, NDVI is significantly and positively correlated with extreme precipitation index, a finding that differs from Zhao, Dai et al's study [6].…”

“…Over the past few decades, regional temperature and precipitation conditions in the region have changed significantly, with extreme weather events occurring frequently and regional vegetation undergoing significant changes [11,23]. Park and Sohn found a significant increasing trend of NDVI in northeast China (35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45) • N, 110-125 • E) during 1982-2006, a weak, increasing trend of NDVI in the area from eastern Mongolia to Manzhouli, and a decreasing trend in the area southeast of Lake Baikal [24]. Zhou, Zhao et al found a significant increase in NDVI during the growing season in southeastern Horqin, China, and a significant decrease in NDVI during the growing season in Hunshandak during 1982-2011 [25].…”

Evaluation of Present-Day CMIP6 Model Simulations of Extreme Precipitation and Temperature over the Australian Continent

“…2. To capture extremes which have an impact on society and infrastructure; for example, extreme indices like TXge35, TR, and SU have the largest impacts on health [49], whereas indices like Rx1day, CDD, and CWD have the largest impact on agriculture, water resources and the economy [50,51].…”