Spatial and Temporal Distribution of Temperature Changes in Southern Shaanxi
陕南气温变化的时空分布

During the past century, global climate has gone through a significant change of which global warming is the main characteristic. As the water source of Middle Route Project of South-to-North Water Transfer Project in China, the temperature change of Southern Shaanxi has been much concerned. Besides, enriching the study of temperature changes in southern Shaanxi can provide a strong basis for industrial and agricultural production, ecological and environmental protection and the government work in this area. Using the temperature data during 1980-2010 from 28 meteorological stations in southern Shaanxi and surrounding areas, we have got the feature vector distribution of temperature and the time-coefficient series with methods of Empirical Orthogonal Function (EOF) and Mann-Kendall. The innovation points of this study are that it has analyzed the situation of temperature change with time in southern Shaanxi as well as the spatial distribution pattern of temperature change in this region. The research results show that: 1) During the study period, the temperature of southern Shaanxi showed a wavelike rising tendency with 1994 as the point of abrupt change; 2) The distribution of temperature changes in southern Shaanxi has obvious characteristics: affected by the latitude, the temperature is high in south and low in north; affected by the topography, the temperature change in mountains shows an opposite trend to that in basins; affected by the monsoon climate, there is also an opposite trend of temperature changes between eastern and western regions; it is a common trend that most areas share high temperature or low temperature; 3) The time-coefficient series of temperature field has a significant inter-annual variation, and the fluctuation continues to grow stronger during the year. Mann-Kendall and EOF can greatly reveal the spatial and temporal characteristics of temperature changes in the study area, but there are relatively short time series and small space points in this study. From now on, we could combine temperature changes with precipitation changes so as to better reflect the hydrothermal conditions in the research area.