台湾海峡西岸主要流域降水时空分布特征的研究

发布时间：2018-03-07 07:07

本文选题：TRMM降水　切入点：台湾海峡　出处：《厦门大学》2014年硕士论文　论文类型：学位论文

【摘要】：流域降水研究对于流域营养盐和污染物输运、河口冲淡水及其生态效应、近海海洋生态系统变化等诸多研究领域都具有重要意义。本研究对TRMM遥感降水资料进行了区域适用性评估,在确保该资料集能真实反映台湾海峡及其邻近区域降水分布趋势的前提下,综合使用EOF分析、功率谱分析、EMD分析等多种方法,借助TRMM遥感数据高空间覆盖度的优势,探讨台湾海峡及其邻近区域,尤其是台湾海峡西岸主要流域的降水、强降水的时空变化特征。首先,基于1998-2012年TRMM3B43月降水数据的台湾海峡及其邻近区域降水分布基本特征的研究结果显示：每年的4-9月为台湾海峡及其邻近区域的丰水季节,多年平均的月降水量在部分地区可高达300mm以上;冬季为枯水季节,绝大部分地区的月降水量小于100mm。该地区降水来源,一是来自于春夏之交西南暖湿空气和变性的大陆冷空气相遇所形成锋面经过此地区所产生的降水,二是夏季台风带来的强降水。在春夏之交,强降水区主要位于闽西北地区,夏季则主要位于台湾岛南部地区以及福建沿海。1998-2012年台湾海峡及其邻近区域年降水量的变化相当显著,不同流域的年际变化趋势不太一样。接着,本文应用EOF分析、功率谱分析等方法对台湾海峡西岸闽江、九龙江和韩江流域降水的时空分布特征进行了深入分析。EOF分解的第一模态主要体现了丰水期和枯水期的年变化特征,空间分布表现出整体一致性,变化幅度均以山区为最大；锋面、地形降水起着决定性影响。第二模态主要体现后汛期降水与其它季节降水分布特征的差异,空间分布上主要表现为或东南-西北反相、或南-北反相型的分布格局。此外,三个流域降水在不同季节的年际变化都相当显著,尤其是雨季,年际变化幅度最大。夏季降水与南海夏季风强度的变化存在较好的正相关；El Nino事件对闽江流域西北部影响最为显著,对三个流域枯水期降水的影响范围最大,降水量均较正常状态偏多；而La Nina事件期间,三个流域的降水均比正常状态要少,内陆地区减少的幅度比沿海更大。最后,本文利用1998-2012年TRMM3B42日降水资料,对台湾海峡西岸各流域的极端强降水事件进行了统计分析。在空间分布上,各流域强降水最为频发、显著的区域多为山区和沿海地带；在年变化上,闽江、韩江流域强降水主要集中在雨季,九龙江流域强降水年变化则表现为典型的双峰结构。在年际变化上,三个流域丰水期强降水均呈现出一定的周期性波动,枯水期强降水整体上表现为较明显的上升趋势；十五年来,闽江流域、九龙江流域年强降水日单调增加,韩江流域年强降水日单调递减,各流域均表现出3种不同尺度的变化周期,分别为2-3年、5年左右、9-10年。
[Abstract]:Watershed precipitation studies on the transport of nutrients and pollutants, estuarine flushing fresh water and its ecological effects, Many research fields such as offshore marine ecosystem change are of great significance. In this study, the regional applicability of TRMM remote sensing precipitation data is evaluated. On the premise of ensuring that the data set can truly reflect the precipitation distribution trend in the Taiwan Strait and its adjacent areas, the advantages of high spatial coverage of TRMM remote sensing data are obtained by using various methods such as EOF analysis, power spectrum analysis and EMD analysis. The temporal and spatial variation characteristics of precipitation and strong precipitation in the Taiwan Strait and its adjacent regions, especially in the main watersheds of the West Bank of the Taiwan Strait, are discussed. First of all, based on the monthly precipitation data of TRMM3B43 from 1998 to 2012, the basic characteristics of precipitation distribution in the Taiwan Strait and its adjacent areas show that the April to September of each year is the high water season of the Taiwan Strait and its adjacent areas. The annual average monthly precipitation can be as high as 300mm in some areas, and the winter is the dry season, and the monthly precipitation in most areas is less than 100mm. the source of precipitation in this area is, One is the precipitation produced by the front of the southwest warm and wet air and the denatured continental cold air in the turn of spring and summer, and the second is the strong precipitation caused by the summer typhoon. At the turn of spring and summer, the strong water drop area is mainly located in the northwest of Fujian. In summer, the annual precipitation in the Taiwan Strait and its adjacent areas in the southern part of Taiwan Island and in the coastal area of Fujian Province is quite significant, and the interannual variation trend of different watersheds is not quite the same. Then, EOF analysis and power spectrum analysis are used to analyze the Minjiang River on the west side of the Taiwan Strait. The characteristics of temporal and spatial distribution of precipitation in Jiulong River and Hanjiang river basins were analyzed deeply. The first mode of EOF decomposition mainly reflected the annual variation characteristics of high water period and low water period. The spatial distribution showed overall consistency, and the range of change was the largest in mountainous area. The second mode mainly reflects the difference of precipitation distribution between the later flood season and other seasons, and the spatial distribution mainly shows the inverse phase between southeast and northwest. In addition, the interannual variation of precipitation in the three watersheds is quite significant in different seasons, especially in the rainy season. There is a good positive correlation between the summer precipitation and the intensity of the South China Sea summer monsoon. The El Nino event has the most significant influence on the northwestern Minjiang River Basin, and has the greatest influence on the precipitation in the three basins during the dry season. During the La Nina event, the precipitation of the three basins was less than that of the normal state, and the decrease of the inland area was larger than that of the coastal area. Finally, based on the daily precipitation data of TRMM3B42 from 1998 to 2012, this paper makes a statistical analysis of the extreme heavy precipitation events in each watershed in the west coast of the Taiwan Strait. In terms of spatial distribution, the heavy precipitation in each watershed is the most frequent, and the most significant areas are mountainous areas and coastal areas. In terms of annual variation, the strong precipitation of Minjiang River and Hanjiang River is mainly concentrated in the rainy season, and the annual variation of strong precipitation in Jiulong River basin is a typical bimodal structure. Over the past 15 years, the annual strong precipitation in Minjiang River Basin and Jiulong River Basin has increased monotonously, while that in Hanjiang River Basin has been decreasing. The variation periods of three different scales were observed in each watershed, ranging from 2-3 years to 9-10 years.
【学位授予单位】：厦门大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P732.1

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