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Research on Temporal Evolution and Spatial Pattern in the Desert Region of Northern China

Author: XuLiGang
Tutor: ZhouHongFei
School: Shihezi University
Course: Agricultural Soil and Water Engineering
Keywords: The northern desert area Inland River Basin MODS system Precipitation Space - time evolution Wavelet Analysis EOF decomposition Geostatistics Mann-Kendall rank method
CLC: P426.613
Type: Master's thesis
Year: 2008
Downloads: 271
Quote: 1
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Abstract

Desert region in northern China are mainly located in the the northwest inland river basins, the Yellow River and the Inner Mongolia Plateau in arid, semi-arid areas, belonging to Xinjiang, Qinghai, Gansu, Inner Mongolia, Ningxia, Shaanxi, Shanxi, Hebei and other provinces and autonomous regions, an area of ??about 340 million square kilometers, accounting for about 35% of the area of ??the country. Desert area in north China precipitation is scarce, the spatial and temporal distribution is very uneven, irrational use of land resources led to severe degradation of ecological and environmental, northern China and Northeast Asia, the main source of sand. Ecological and environmental construction are the major problems faced in the area to achieve sustainable social and economic development. Research Desert Area Temporal and Spatial Variation Trend and Characteristics of precipitation desert areas degraded ecosystem protection and restoration, the regional socio-economic and ecological environment coordinated development of important guiding significance. In this thesis, China's northern desert region of 35 typical weather station monthly precipitation data from 1955 to 2005, in-depth analysis on China's northern desert region of precipitation differentiation law Fengku the trend; using Fukang Station of Desert Ecology, Chinese Academy of Sciences rainfall observation network in the the Sangong River basin rainfall from May to August 2007, northwest inland arid area Mountain - Oasis - Desert System (MODS) the spatial variability of precipitation characteristics were analyzed. The main conclusions are as follows: (1) Spatial and temporal variability of precipitation in the northern desert region, the past 50 years, China's northern desert region of precipitation in time and space, both showed large variability. Expected future, spring, summer precipitation will increase in winter precipitation gradually reduced, the increasing trend of annual precipitation; increase in rainfall over large areas of eastern Inner Mongolia gradually shifted to the northwest. There are 5, 9 and 14 years of quasi-primary cycle, mutations are located in 1963,1988,1996 and 2001; precipitation to 9 years and 14-year cycle since 1988. Precipitation spatial distribution pattern of white complex \contribution to the overall change in variance 70.4%). \the possibility of drought. Temporal and Spatial Trends in precipitation in the northern desert region, around the separate wet years the probability is higher than the a separate dry years, and even dry year is higher than the probability of even the Harvest; extreme drought area and arid zone rainfall increase trends in the region were 83% and 70% probability, and semi-arid regions significantly decreasing the probability of precipitation 58%. Located in an arid area of ??Xinjiang, Qinghai and Gansu precipitation will increase, and is located in semi-arid eastern Inner Mongolia precipitation will reduce the differences in the distribution of precipitation during the year will be slowing down; northern desert region of western and eastern precipitation fluctuations in the central region have slowed the trend of inter-annual fluctuations increasing trend. Range between 15% to 78%, which, inter-annual variation in southern Xinjiang and Qinghai, in most parts of the coefficient of variation of more than 40% of the Inner Mongolia region is relatively stable around 28%. 3 in arid central MODS precipitation temporal and spatial variation, application EOF REOF law, geostatistics analysis the Sangong River basin rainfall observation network data. The results show that: according to the 0-30km ,30-60km and 60-150km at the three load segments, with the the Sangong River Valley Mountain oasis and desert three different landscape geomorphic units north-south distance anastomosis; precipitation increase from Mountain oasis, desert in turn decreases; the mountain precipitation variogram Gaussian model, oasis precipitation in line with spherical variogram model, the desert area of ??precipitation variogram model each month. Precipitation spatial heterogeneity caused by random factors in the scale of the study only the total spatial heterogeneity of 0% -9.57%, mainly caused by spatial autocorrelation spatial heterogeneity. Each time around the sill, dimension and variable range characteristic parameters change to determine the maximum precipitation spatial variability of the oasis region, mountain, followed by the desert minimum; the geomorphic units rainfall space anisotropy is not significant. The purpose of the whole basin, June precipitation space heterogeneity of the most significant, in August the minimum spatial variation, with the coefficient of variation is consistent; rainfall is strongest in the north-south direction (0 °) and the variability of the southeast - northwest (135 °) .

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CLC: > Astronomy,Earth Sciences > Atmospheric science (meteorology ) > Meteorological elements,atmospheric phenomenon > Water vapor,condensation,and precipitation > Precipitation > Ordinary precipitation > Surface distribution
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