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Research on the Precipitation Change and Its Impacts in Hexi Area

Author: WangSuPing
Tutor: SongLianChun；HanYongXiang
School: Lanzhou University
Course: Meteorology
Keywords: Hexi area Precipitation Change Affect
CLC: P332.1
Type: Master's thesis
Year: 2007
Downloads: 302
Quote: 7
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Abstract

Water resources in Hexi area all production, the lifeblood of the life, and the precipitation is the total supply of water resources in the Hexi area, therefore, in-depth study of the regional precipitation changes in the characteristics and laws of the reveal the entire Hexi area of ??water resources characteristics to guide regional ecological building and restore important. This article uses the Hexi area of ??precipitation measured data, the establishment of the British University of East Anglia climate center land surface precipitation gridded data Hexi area nearly 60 years the regional precipitation sequence reveals a typical inland river region regional precipitation characteristics and evolution itself ; at the same time, the article also Hexi Qilian Mountains and its nearby tree ring data, Hexi area drought and flood level data as well as historical literature Hexi the Qilian District 102 elderly precipitation sequence and analyze the changes in the Qilian Mountain area of ??precipitation over the past century trends, cycles and mutation characteristics; Finally, the combination of the Hexi area three times of drought events centuries, explores the impact of precipitation changes on regional economic and social development. The main conclusions of this study are as follows: (1) Hexi area of ??arid and semi-arid climate, scarce rainfall and uneven distribution of precipitation from south to north, from east to west to reduce. Qilian Mountains than abundant rainfall, the average annual precipitation is between 250 ~ 600mm, the Hexi Corridor plains area precipitation is scarce. (2) nearly 40 years in Hexi area precipitation generally increasing trend, but the increase is not very obvious. (3) affected by the terrain, location and climate system, Hexi regional precipitation characteristics slightly different: the Qilian area is Hexi precipitation most years average rainfall of 345mm, more than 20 stations in the region years of average precipitation; followed by the Hexi eastern area, the average annual rainfall is 220mm, slightly higher than the region's many years of precipitation; the Hexi western area for many years an average of 84mm, less than the region's average for many years; Mazongshan precipitation in the area at least for 74mm. The past 46 years, the the Hexi eastern precipitation smaller increase in trend; weak trend of an increase in precipitation in the Qilian Mountains; precipitation of the the Hexi western area did not change significantly, mainly natural changes: Mazongshan precipitation in the area was weak decreasing trend. (4) 1901-2002, Hexi Qilian area precipitation weak trend in the increase, but did not reach a significant level inspection, precipitation changes still naturally fluctuating main; modest precipitation changes of the early 20th century, the Qilian Mountains, while 20 The late amplitude; Qilian Mountains in the 20th century there are three distinct drier period, respectively, in the mid-1920s to the mid-1930s, the late 1950s to the mid-1960s and the end of the 20th century to 2001. (5) through power spectral analysis and wavelet analysis: 2a so, 4a and 5a cycle is a cycle of precipitation in Qilian Mountains, In addition, the region precipitation 7a ,12-17a ,32-37a cycle. Precipitation cycle changes about to about 1980 as the dividing line, this smaller precipitation cycle, mainly the main period of about 3-5 years, after the 1980 cycle, mainly for seven years mainly cycle. Visible Qilian Mountains precipitation cycle tended to increase precipitation in wet and dry oscillation gradually stabilized by frequent. (6) through mutation test obtained in 1940 and 1964 for annual precipitation of the 20th century, Hexi Qilian Mountains region has experienced strong mean mutation, which, in 1925 and 1954, precipitation experienced by the high side to the low mutation precipitation below normal to above normal mutation ,1987-1989 the Hexi the Qilian District precipitation there is no obvious mutations. (7) The Qilian Mountains precipitation changes affect the abundance of regional water resources, lead to the Hexi regional disasters such as drought and shortage disaster, affecting regional economic and social development of the important factors, Hexi history of the Republic of China's 18-year drought in the early 1960s, three years of difficult times low value area of ??the drought, and the drought in the late 1990s corresponds to the precipitation of the Qilian Mountains three significant, severe drought showed periodic variation of 33-35a, there is consistency with the cycles of precipitation 32-37a. (8) the implementation of artificial precipitation (snow), to increase water resources in the Qilian Mountains; strengthen basin-wide water resources management and rational allocation and use of water resources; improve social and drought mitigation capability is enhanced regional climate adaptability, an important way to achieve sustainable development .

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CLC: > Astronomy,Earth Sciences > Geophysics > Hydrological Sciences (water sector physics) > Hydrological observations (tests ) > Precipitation Measurement
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