兰州大学机构库 >资源环境学院
1997-2016年中国极端降水事件时空变化与特征分析
Alternative TitleANALYSIS OF SPATIO-TEMPORAL CHANGES AND CHARACTERISTICS OF EXTREME PRECIPITATION EVENTS IN CHINA DURING 1997-2016
万昌君
Thesis Advisor吴小丹 ; 叶思菁
2019-05-30
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name学士
Degree Discipline地图学与地理信息系统
Keyword时空扫描统计 极端降水 热点探测 局部空间自相关 GIS
Abstract相关研究表明由于人类活动的影响,地球正经历以全球变暖为主要标志的气候变化。随着全球变暖,水文循环的加剧导致全球极端降水频率和强度逐渐增加。降水作为全球生态水文循环中具有高度时空变异性的气候变量,极端降水事件对人类社会经济发展、生态环境保护都产生了严重的灾害影响。因此,对极端降水的研究一直是学界的研究热点。但目前对极    端降水事件的研究多采用单站阈值,或某站发生极端降水事件时其余台站发生极端降水事件的多站概率指标,来研究极端降水事件的空间分布。上述方法都重点考虑了极端降水事件的空间属性,忽略了其时间特性。而往往长时间的极端降水事件更容易引起大范围的洪涝灾害,以及泥石流滑坡等次生灾害。因此,抛开时间过程,单独研究极端降水事件的空间格局是个不可忽视的问题。本文创造性的采用时空扫描统计方法,综合极端降水事件的空间特征与时间特征,提取极端降水事件的时空聚集区,并采用对数似然比(LLR)和相对风险度(RR)两个指标对极端降水聚集区时空聚集特征进行定量评价。以1997-2016年降水格点数据(Global Precipitation Climatology Project)为例,基于伯努利分布模型探究了时空扫描法提取极端降水时空聚集区的可行性。同时为研究全国极端降水事件时空聚集特征与演化规律,分别对比分析了2016年7月份极端降水与2016年夏季(6-9月)极端降水扫描结果,和1997-2016年逐年夏季(6-9月)极端降水扫描结果。得出以下结论:①2016年我国夏季(6-9月份)极端降水事件聚集区主要分布在7月份;②我国极端降水事件时空聚集区发生时间基本从南到北递增,但新疆地区时空聚集区发生时间较早,有些年份发生在6月份,时间跨度大,往往从7月一直到8月中旬;③1997-2016年我国夏季极端降水事件逐年发生次数大致以8为均数波动变化,但时空聚集区的强度有增加的趋势;④我国西北区、北疆、西南地区极端降水时空聚集性和致灾性增强明显,长江中下游和华南地区的极端降水时空聚集性略有增加,东北地区极端降水时空聚集性仍明显,但发生频率和强度都有减弱的趋势。
Other AbstractRelated studies have shown that due to the impact of human activities, the Earth is experiencing climate change characterized by global warming. With global warming, the intensification of the hydrological cycle has led the extreme precipitation more frequent and   more intensity worldwide. Precipitation is a climate variable with high spatial and temporal variability in the global eco-hydrological cycle. Extreme precipitation events always had serious disaster impacts on human socio-economic development and ecological environmental. Therefore, the study of extreme precipitation has been a research hotspot in the academic world. However, the current research on extreme precipitation events mostly uses the single station threshold, or the multi-station probability index. Above methods mainly focus on the spatial properties of extreme precipitation events, ignoring their temporal characteristics. However, extreme precipitation events lasting long-term are more likely to cause serious floods, as well as secondary disasters such as mudslides and landslides. Therefore, studying the spatial pattern of extreme precipitation events alone aside from the time process is a problem that cannot be ignored. This paper uses the spatial-temporal scanning statistical method to synthesize the spatial characteristics and temporal characteristics of extreme precipitation events, extract the spatial-temporal gathering areas of extreme precipitation events, and adopt log-likelihood ratio (LLR) and relative risk (RR) indicators which quantitative evaluating temporal and spatial aggregation characteristics of extreme precipitation areas. Taking the 1997-2016 Global Precipitation Climatology Project as an example, based on the Bernoulli distribution model, exploring the feasibility of spatial-temporal scanning to extract the temporal and spatial accumulation areas of extreme precipitation. At the same time, in order to study the temporal and spatial aggregation characteristics and evolution laws of extreme precipitation events in China, comparing the extreme precipitation in July 2016 and the extreme precipitation scan results in summer 2016 (June-September) and the summer of 1997-2016 (6-9month). The conclusions are as follows: First, the accumulation period of extreme precipitation events in 2016 summer (June-September) mainly distributed in July; Second, the time of occurrence of extreme precipitation events ‘clusters in China increased from south to north. But the time of occurrence of extreme precipitation events ‘clusters in Xinjiang occurred earlier, some years occur in June, and the time span is large, often from July to mid-August; Third, the annual occurrence of extreme precipitation events in China from 1997 to 2016 is about 8 fluctuations in average, but the intensity of the increase has an increasing trend; Fourth, the temporal and spatial clustering and catastrophic increase of extreme precipitation are obvious in the northwestern, northern and southwestern regions of China; The temporal and spatial clustering of extreme precipitation is slightly increased in the middle and lower reaches of the Yangtze River and southern China; The extreme precipitation's aggregation in the northeast is still evident, but the frequency and intensity of the occurrence are weakening.
Pages44
URL查看原文
Language中文
Document Type学位论文
Identifierhttp://ir.lzu.edu.cn/handle/262010/344373
Collection资源环境学院
Affiliation资源环境学院
First Author AffilicationCollege of Earth Environmental Sciences
Recommended Citation
GB/T 7714
万昌君. 1997-2016年中国极端降水事件时空变化与特征分析[D]. 兰州. 兰州大学,2019.
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