Resources Science ›› 2017, Vol. 39 ›› Issue (11): 2153-2165.doi: 10.18402/resci.2017.11.13

• Orginal Article • Previous Articles     Next Articles

Spatio-temporal variations of extreme precipitation from 1961 to 2015 in the eastern inland river basin of Inner Mongolian Plateau

LI Wei1, DUAN Limin1, LIU Tingxi1, Geriletu2, GAO Ruizhong1, Buren Scharaw3, YU Changxiang4   

  1. 1. College of Water Conservancy and Civil Engineering/ Inner Mongolia Water Resource Protection and Utilization Key Laboratory,Inner Mongolia Agricultural University ,Hohhot 010018,China;
    2. Tongliao Hydrological Survey Bureau,Tongliao 028006,China;
    3. Application Center for System Technologies,Fraunhofer IOSB,Ilmenau 98693,Germany;
    4. Tongliao Soil and Water Conservation Bureau,Tongliao 028099,China
  • Online:2017-11-20 Published:2017-11-20

Abstract: Understanding the spatial and temporal variations of extreme precipitation is of important significance for the relevant studies on hydrological ecology in a basin. In this paper,we use the grid data of precipitation (with a resolution of 0.5°×0.5°)in the eastern part of inland river basin of the Inner Mongolian Plateau from 1961 to 2015 as the basis of study and adopt the methods of climatic diagnosis (e.g.,M-K method,principal component analysis,and correlation analysis)to examine the spatial and temporal variations of six extreme precipitation indexes. Moreover,we study the response of extreme precipitation events to El Niño-Southern Oscillation (ENSO)events. The results indicate that in recent 55 years,the inter-annual variation trend of extreme precipitation indexes for the study area is generally dominated by declination,except for the maximum precipitation over 5 days (RX5DAY)and the heavy precipitation (R95P). In particular,the region with decreasing consecutive dry days (CDD)accounts for 91% of the entire basin,6.7% of which is showing a significant downward trend. Except CDD,all the extreme indexes of the study area exhibit a spatial distribution pattern of "high in the east and low in the west",and the average SDII ranges from 3.8 to 5.3mm/d,with relatively small spatial differences. To some extent,CDD and R95P can be used to characterize the drought events and the heavy rainfall events,respectively,and they both have strong correlations (at a significance level of α=0.1)with the other indices that belong to the same category of extreme event. Moreover,more droughts may be observed in El Nino years,while the flood disasters may occur more frequently in La Nina years.

Key words: ENSO events, extreme precipitation, inland river basin, Inner Mongolian Plateau, spatial and temporal variation