地理研究 ›› 2019, Vol. 38 ›› Issue (7): 1820-1832.doi: 10.11821/dlyj020190088

• 论文 • 上一篇    下一篇

1960—2016年黄土高原多尺度干旱特征及影响因素

孙艺杰(), 刘宪锋(), 任志远, 李双双   

  1. 陕西师范大学地理科学与旅游学院,西安 710119
  • 收稿日期:2019-01-28 修回日期:2019-06-02 出版日期:2019-07-20 发布日期:2019-07-12
  • 作者简介:

    作者简介:孙艺杰(1991-),女,辽宁兴城人,博士研究生,主要研究方向为资源环境与GIS。E-mail: jessicasun@snnu.edu.cn

  • 基金资助:
    国家自然科学基金项目(41801333,41701592);中国博士后科学基金(2019M650859,2019T120142)

Spatiotemporal variations of multi-scale drought and its influencing factors across the Loess Plateau from 1960 to 2016

Yijie SUN(), Xianfeng LIU(), Zhiyuan REN, Shuangshuang LI   

  1. School of Geography and Tourism, Shaanxi Normal University, Xi’an 710119, China
  • Received:2019-01-28 Revised:2019-06-02 Online:2019-07-20 Published:2019-07-12

摘要:

明晰黄土高原干旱特征对于生态工程建设和社会经济可持续发展具有至关重要的作用。基于1960—2016年黄土高原59个气象台站数据和标准化降水蒸散指标(SPEI),本文分析了黄土高原多尺度干旱时空变化特征,并探讨了遥相关指数对黄土高原干旱变化的影响。结果表明:① 黄土高原SPEI指数呈下降趋势,其中70年代初和90年代末为显著干旱时期,80—90年代初为较湿润时期;② 年尺度SPEI呈下降趋势的区域遍布整个黄土高原,以山西西部、宁夏北部和甘肃中东部最为显著,而黄土高原西北和西南部则表现为变湿趋势;③ 春、夏和秋三季SPEI均呈下降趋势,且夏、秋季下降趋势较大,趋势系数均为-0.03/10a。春季干旱趋势与年际变化较为一致,秋季干旱趋势范围较大,占总面积的64.53%,冬季干旱范围较小且不显著;④ 多尺度干旱同时受IOD、NAO、PDO、AMO和ENSO3.4等遥相关指数的共同影响,且该影响存在明显的年际和年代际相位转换特征。多元回归分析显示,IOD和NAO对黄土高原干旱解释率较高,分别为22.98%和12.23%,而ENSO3.4解释率较低,表明黄土高原降水变化与西南季风具有较好的关联性。

关键词: 黄土高原, 多尺度干旱, 标准化降水蒸散指数, 遥相关指数

Abstract:

Clarifying the spatiotemporal changes of drought and its influencing factors is of vital importance to the construction of ecological engineering and the sustainable development of social economy in the Loess Plateau. Using the daily precipitation data of 59 meteorological stations in the Loess Plateau, this paper attempts to describe the temporal and spatial variation trends of drought in the region on multi-time scales during 1960-2016. Based on Standardized Precipitation Evapotranspiration Index (SPEI), Sen+Mann-Kendall analysis, correlation analysis and other climate diagnosis methods, we analyzed the relationship between atmospheric circulation anomalies and drought variations. The results showed that: (1) The SPEI presented a downward trend in recent 57 years, showing a tendency from wet to dry. However, the change trend was not significant and the decline rate was only 0.032/10a. The significant drought trend occurred since the early 1970s and the late 1990s, the water-loggings were frequent during 1980s to the early 1990s. (2) The interannual SPEI (SPEI-12) indicated that there was a consistent drought trend in the whole Loess Plateau, the western part of Shanxi Province, the northern part of Ningxia Hui Autonomous Region, the central-eastern part of Gansu, Hohhot in Inner Mongolia Autonomous Region and Huashan in Shaanxi Province, which showed an significant drought trend, while a wetting tendency was observed in northwest and southwest parts of the Loess Plateau, and the north of Henan Province, moreover the increasing trend was obvious in Jingtai in Gansu Province and Xining in Qinghai Province, with the trend coefficient being respectively 0.36/10a and 0.35/10a. (3) On the inter-seasonal scales, drought trends were found in three seasons except winter, among them summer and autumn were remarkable, the decline rate was similar, at 0.03/10a. In spatial variation, there existed a regional difference of seasonal drought trend. The variation trend of spring drought was consistent with the interannual variation, in autumn the drought trend covered a larger range, which accounted for 64.53% of the total study area, while in winter the scope of drought decreased and was non-significant, and only 33.29% of meteorological stations showed a trend of drought. (4) IOD, NAO, PDO, AMO and ENSO3.4 were the dominant influencing factors for annual and seasonal precipitation variability over the Loess Plateau, the influence had obvious characteristics of interannual and interdecadal phase transition. Multiple regression model indicates that IOD and NAO could well explain drought variations over the Loess Plateau, which accounted for 22.98% and 12.23% of drought, respectively, compared to ENSO3.4. Our results suggest that precipitation over the Loess Plateau has a good correlation with Southwest Monsoon.

Key words: Loess Plateau, multi-scale drought, standardized precipitation evapotranspiration index, climate indices