Increased extreme hourly precipitation over China\u2019s rice paddies from 1961 to 2012

Yiwei Jian,Bengang Li,Jin Fu,Feng Zhou

doi:10.1038/s41598-020-67429-0

Abstract

Rice yield have been affected by the increased extreme precipitation events in recent decades. Yet, the spatio-temporal patterns of extreme precipitation by rice type and phenology remain elusive. Here, we investigate the characteristics of four extreme precipitation indices across China’s rice paddy and their potential association with crop yields, by using hourly precipitation data from 1,215 stations and rice phenology observations from 45 sub-regions. The data indicate that hourly extreme precipitation have significantly increased in 1961–2012 for single rice and early rice in China but not for late rice. Rice were mainly exposed to extreme precipitation from transplantation to flowering stages. The frequency and proportion of extreme precipitation were significantly increased by 2.0–4.7% and 2.3–2.9% per decade, respectively, mainly in south China and Yangtze River Basin. The precipitation intensity and maximum hourly precipitation were increased by 0.7–1.1% and 0.9–2.8% per decade, respectively, mainly in central China and southeast coastal area. These extreme precipitation indices played a role as important as accumulated precipitation and mean temperature on the interannual variability of rice yields, regardless of rice types. Our results also highlight the urgencies to uncover the underlying mechanisms of extreme precipitation on rice growth, which in turn strengthens the predictability of crop models.

Highlights

Rice yield have been affected by the increased extreme precipitation events in recent decades
Using hourly precipitation data (1,215 stations) and rice phenology observations (45 sub-regions), we investigated the spatiotemporal patterns of extreme precipitation indices over three rice cropping systems during 1961–2012, and tested the association between the long-term exposure to extreme precipitation and rice yield in the last three decades (1981–2012) due to data limitation
The frequency in the period 2 and 3 were significant higher than those in period 1 and 4 for single rice and early rice (p < 0.001), while for late rice higher frequency occurred in period 1 and 2 (Fig. 1a)

Summary

Introduction

Rice yield have been affected by the increased extreme precipitation events in recent decades. The data indicate that hourly extreme precipitation have significantly increased in 1961–2012 for single rice and early rice in China but not for late rice. The frequency and proportion of extreme precipitation were significantly increased by 2.0–4.7% and 2.3–2.9% per decade, respectively, mainly in south China and Yangtze River Basin. The precipitation intensity and maximum hourly precipitation were increased by 0.7–1.1% and 0.9–2.8% per decade, respectively, mainly in central China and southeast coastal area. These extreme precipitation indices played a role as important as accumulated precipitation and mean temperature on the interannual variability of rice yields, regardless of rice types. Identify extreme precipitation indices during different rice-growing periods and unravel the potential effects of extreme precipitation on rice growth

Objectives

Methods

Results

Conclusion