1961-2010年新疆极端降水过程时空特征
作者简介:慈晖(1989- ),女,甘肃临夏人,博士,主要从事区域水文循环与水资源演变研究。E-mail: cathyyyci@gmail.com
收稿日期: 2014-01-10
要求修回日期: 2014-06-05
网络出版日期: 2014-10-10
基金资助
新疆维吾尔自治区科技计划项目(201331104)
中山大学滨海小流域自然地理综合过程观测与实验平台建设(2012年度)
Spatiotemporal variations of extreme precipitation events within Xinjiang during 1961-2010
Received date: 2014-01-10
Request revised date: 2014-06-05
Online published: 2014-10-10
Copyright
采用新疆50个气象测站1961-2010年逐日降水资料,选用14个极端降水指数探讨新疆极端降水事件的发生与变化。结果表明:无论平均降水过程还是极端降水过程,均能反映新疆明显的湿润化趋势。伴随降水量的增加,降水强度及降水频率均增大,除CDD变化表现为下降趋势外,其他指数变化均呈上升趋势。分析各极端降水指数序列变化,20世纪60-70年代年际变化幅度小,稳定性好;80-90年代年际差异大,稳定性差;新疆东部各极端降水指数上升与下降趋势小幅交替出现,而北疆、南疆及全疆极端指数序列则呈明显且单一的上升趋势。各极端降水指数最大概率变异年为1986年、2009年;降水变异后,新疆弱降水过程变化不明显,但强降水过程变幅增大,易导致洪旱灾害等极端气象水文事件的发生。
慈晖 , 张强 , 张江辉 , 白云岗 , 刘剑宇 . 1961-2010年新疆极端降水过程时空特征[J]. 地理研究, 2014 , 33(10) : 1881 -1891 . DOI: 10.11821/dlyj201410009
With the development of global climate change, extreme climate events have drawn attention of worldwide researchers not only due to their direct impact on socio-economy, but also as climate change indicators. Human and natural systems have been affected by extreme climate events to a great extent. The main objective of our study is to detect the possible changes and intensity, tendency and frequency of extreme climate events. Xinjiang is located in the inland China, where the climate is arid to semi-arid. Xinjiang is therefore highly vulnerable to climate variability, and a better understanding of changes in extreme precipitation events plays an increasingly role in the arrangement of agricultural production and the process of agricultural planning. Fourteen extreme precipitation indices have been selected and spatiotemporal patterns of extreme precipitation events have been analyzed based on daily precipitation data from 50 stations covering the period of 1961-2010 using statistical methods. The results indicate that precipitation amount is in an upward trend with increasing precipitation intensity and precipitation frequency. With the increase of precipitation, evident decrease of CDD can be found and increasing trend can be identified by RR1, RR5, RR10, R95P, Rx1day and Rx5day. This result show obvious wetting tendency in Xinjiang. However, different time periods are dominated by different changing properties of precipitation regimes. With smaller variability and higher stability, precipitation amount level during 1960-1970s is lower. The period of 1980-1990s can be taken as the transitional period characterized by abrupt increase of precipitation amount and lower stability, and according to unsteady precipitation variations in recent years, higher precipitation variability can be found after the 1990s. Spatially, increasing and decreasing trends of precipitation variations alternate in eastern Xinjiang with small amplitudes; however, evident increase of precipitation can be found in the northern, southern and the entire Xinjiang region. Alteration of precipitation variations was found mainly in 1986 and 2009. After occurrence of precipitation alteration, strong precipitation processes are subject to higher variability and moderate changing characteristics are found in weak precipitation processes. This study will be of great merits in terms of development of human understanding of regional responses of hydrological cycle to climate changes in Xinjiang.
Key words: Xinjiang; extreme precipitation events; MK trends; abrupt changes
Tab. 1 Definition of 14 extreme precipitation indices表1 14个极端降水指数定义 |
| 缩写 | 定 义 | 单位 |
|---|---|---|
| CDD | 年内日降水量连续低于1 mm的日数最大值 | d |
| CWD | 年内日降水量连续高于等于1 mm的日数最大值 | d |
| Rx1day | 月内1日降水量最大值 | mm |
| Rx5day | 月内连续5日降水量最大值 | mm |
| PRCPTOT | 年内日降水量≥ 1 mm的降水量之和 | mm |
| GPRCP | 年内5-8月(生长季节)降水量之和 | mm |
| R75 | 年内日降水量高于标准时段日降水量序列第75百分位值的日数之和 | d |
| R95 | 年内日降水量高于标准时段日降水量序列第95百分位值的日数之和 | d |
| R95P | 年内日降水量高于标准时段日降水量序列第95百分位值的降水量之和 | mm |
| R99P | 年内日降水量高于标准时段日降水量序列第99百分位值的降水量之和 | mm |
| RR1 | 年内日降水量≥ 1 mm的日数 | d |
| RR5 | 年内日降水量≥ 5 mm的日数 | d |
| RR10 | 年内日降水量≥ 10 mm的日数 | d |
| SDII | 年内日降水量之和与日降水量≥ 1 mm的日数之比 | mm/d |
Fig. 1 Locations of the study region and meteorological stations图1 研究区地形(a)及气象测站(b)分布 |
Fig. 2 Daily precipitation and 5-day moving average before and after change points图2 1986年突变前后全疆日降水量(a)及五日滑动平均值(b) |
Fig. 3 Trends of monthly precipitation in Xinjiang during1961-2010图3 1961-2010年新疆月降水量年际变化趋势分布 |
Fig. 4 Trends of extreme precipitation indices time series with significance tests across Xinjiang图4 极端降水指数趋势变化空间分布及显著性检验 注:饼状图彩色部分为呈上升趋势测站比重,蓝色部分为呈下降趋势测站比重;粗黑线包括的部分表示通过置信度为95%显著性检验的测站比重 |
Fig. 5 Temporal trends and alteration of extreme precipitation indices over the entire Xinjiang (a, e), the northern Xinjiang (b, f), the southern Xinjiang (c, g) and the east part of Xinjiang (d, h) during 1961-2010图5 极端气候指数时间序列趋势变化(左)及变异分析(右) 注:左侧蓝色方向为下降趋势,红色方向为上升趋势,右侧最右列为无变异年概率;a、e-全疆,b、f-北疆,c、g-南疆,d、h-新疆东部 |
Fig. 6 Statistical properties of extreme precipitation indices over Xinjiang图6 新疆极端降水指数年际变化趋势系数分布 注:箱型内部“〇”为序列均值,短黑线为中位数,顶端为序列下四分位值,底端为序列上四分位值;箱须顶端为序列最大值,箱须底端为序列最小值 |
The authors have declared that no competing interests exist.
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