Abstract

Extreme precipitation has significant impacts on human society and agriculture development under global climate change as well as severe effects on rice development. However, little research has been done on the characteristics of extreme precipitation in different rice growth stages. Taking the South China region as a case study, the characteristics of extreme daily precipitation in the early rice season (April–July) from 1960 to 2009 were investigated by using percentile method. Results indicated that extreme precipitation threshold increases since the tillering stage, and there is big difference between the first and the rest growth stages. Extreme precipitation is serious in the eastern part than in the western part of South China during the seeding and tillering stage, and reverse since the booting stage. Frequency of extreme precipitation increases in recent decades after the booting stage. Finally, flood risk regions form more easily in the coastal cities and the western part of South China in the 1990s and 2000s since the tillering stage.

Research Highlights

• Extreme precipitation has significant impact on the rice production in South China region during the early rice period. However, characteristics of extreme precipitation in different rice growth stages are still unclear. The researchers use daily precipitation data (1960–2009) and percentile method to analysis the extreme precipitation distribution in South China region during April–July for early rice season.
• The researchers found extreme precipitation is serious in South China region since tillering stage, and getting more serious when it comes to the rest of the growth stages. High extreme precipitation centers occur in different region during early rice period. Flood protection and crops planning should focus on different region for different stages. Data analysis also show that extreme precipitation is serious in the eastern part than in the western part of South China during the seeding and tillering stage, and reverse since the booting stage. Frequency of extreme precipitation increases in recent decades and more flood risk region form in the coastal cities. Crop planning and disaster managements in South China during early rice period need for careful consideration of different flood risk region in different stages.

中文翻译：

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早稻季节4-7月华南地区极端降水特征

摘要

极端降水对全球气候变化下的人类社会和农业发展产生重大影响，并对水稻发展产生严重影响。然而，关于不同水稻生育阶段极端降水特征的研究很少。以华南地区为例，采用百分位数法研究了1960年至2009年早稻季（4月至7月）的极端日降水特征。结果表明，从分er期开始，极端降水阈值增加，而生育的前，后各阶段差异较大。在播种和分till期，华南东部地区的极端降水比西部地区严重。在启动阶段后的最近几十年，极端降水的频率增加。最后，自分stage阶段以来，在1990年代和2000年代，沿海城市和华南西部地区容易形成洪灾风险区。

研究重点

• 在水稻早期，极端降水对华南地区的水稻生产具有重大影响。但是，尚不清楚水稻不同生育阶段的极端降水特征。研究人员使用每日降水数据（1960–2009年）和百分位数方法分析早稻季节4月至7月华南地区的极端降水分布。
• 研究人员发现，从分ing期开始，华南地区的极端降水十分严重，而在其余生长期，降水却变得更为严重。水稻早期在不同地区出现极高的极端降水中心。防洪和农作物规划应在不同阶段集中于不同地区。数据分析还表明，在播种和分till期，华南东部地区的极端降水比西部地区严重，从孕穗期开始逆转。近几十年来，极端降水的频率增加，沿海城市形成更多的洪灾危险区。南方水稻早稻时期的作物计划和灾害管理需要仔细考虑不同阶段的不同洪水风险区域。