Arid Zone Research ›› 2021, Vol. 38 ›› Issue (3): 733-746.doi: 10.13866/j.azr.2021.03.15

• Weather and Climate • Previous Articles     Next Articles

Evolution characteristics of precipitation resources pattern in Ningxia

WANG Suyan1,2,3(),LI Xin3(),WANG Fan3,MA Yang3,ZHANG Wen3,HUANG Ying3,GAO Ruina3   

  1. 1. Key Laboratory for Meteorological Disaster Monitoring and Early Warning and Risk Management of Characteristic Agriculture in Arid Regions,Yinchuan 750002, Ningxia, China
    2. Key Laboratory of Meteorological Disaster Preventing and Reducing in Ningxia, Yinchuan 750002, Ningxia, China
    3. Ningxia Climate Center, Yinchuan 750002, Ningxia, China
  • Received:2020-05-19 Revised:2020-10-27 Online:2021-05-15 Published:2021-06-17
  • Contact: Xin LI E-mail:nxwsy_cn@sina.com;lixin_720@163.com

Abstract:

Ningxia is in the east of Northwest China,and although it is only more than 400 kilometers from north to south,its climate is quite different. In this paper,the characteristics of the precipitation resources pattern evolution in Ningxia under the background of warm-humid in northwest are analyzed,including the precipitation, the difference between potential evapotranspiration and precipitation,the length of continuous “wet” and “dry” processes,the key isohyets of 200 mm and 400 mm,and precipitation intensity and days of different grades and their contribution to precipitation,the relationship between precipitation and water consumption. The results show that: (1) The annual precipitation decreased on the whole,but the stages characteristics and the regional and seasonal difference were higher. Only the precipitation in spring increased around the year of warm-humid in northwest (1983), but which in all regions and seasons increased since 2011 and was more than that of 1961-1982 and 1983-2010. (2) The higher regional difference of precipitation increasing-range and the regional annual unsynchronism,especially the variation difference between medium and large rainfall made the difference of precipitation between regions more and more big and the probability of “warm-wet” and “warm-dry” phenomenon occur at the same time between the north and the South increases. (3) The potential evapotranspiration increasing and the precipitation decreasing made the difference between evapotranspiration and precipitation increase,which in spring and in autumn separately in the Middle North region and in southern mountains was the most. (4) In the Yellow River Diversion Irrigation Area,the continuous drought process increased,but there was no increase trend of the continuous rainy month,and drought in spring,summer or even in spring and summer was still frequent,so the proportion of agricultural water consumption was still large. While the continuous drought process was shortened and the continuous rainy months increased in the south central part. (5) The 200 mm isoline had a southward trend,and the west side of the 400 mm isoline had a southward trend, and which moved northward with the increase of precipitation. (6) The total days of precipitation decreased and the intensity of precipitation increased. The number of light rainy days in all regions and seasons decreased,and most of the precipitation intensity increased. The contribution rate changed remarkably of moderate and heavy rainfall in spring,all of the four magnitudes rainfall in summer and light and heavy rainfall in autumn. Then the changes of moderate and heavy rainfall in spring, heavy and rainstorm rainfall in summer, light and moderate rainfall in autumn played an important role in the change of total rainfall. The precipitation resources pattern evolution in Ningxia had both advantages and disadvantages,and on the whole, the precipitation increase since 2011 was conducive to the restoration of ecological environment,but it would also increase the extreme precipitation and rainless days also,and the risk of urban waterlogging, mountain flood and debris flow. At the same time,the precipitation difference increasing between the north and the South made the difficulty of disaster prevention and mitigation increase.

Key words: Ningxia, precipitation, pattern of precipitation, evolution characteristics, warm-humid in northwest