Journal of Geographical Sciences ›› 2012, Vol. 22 ›› Issue (2): 223-244.

• Climate Change and Hydrology •

### The characteristics of temperature variability with terrain, latitude and longitude in Sichuan- Chongqing Region

SHAO Jing’an1, LI Yangbing1, NI Jiupai2

1. 1. College of Geographical Science, Chongqing Normal University, Chongqing 400047, China;
2. College of Resources and Environment, Southwest University, Chongqing 400716, China
• Received:2011-02-28 Revised:2011-05-30 Online:2012-04-15 Published:2012-04-15
• About author:Shao Jing’an (1976-), Professor, specialized in regional environment evolution and climate responses. E-mail: shao_ja2003@sohu.com
• Supported by:

Natural Science Foundation of Chongqing, No.2010JJ0069; Science and Technology Great Special Project on Controlling and Fathering Water Pollution during the National 12th Five-year Plan, No.2012ZX07104-003

Abstract:

Using the daily temperature data of 95 meteorological stations from Sichuan- Chongqing Region and its surrounding areas, this paper adopted these methods (e.g., linear regression, trend coefficient, geographical statistics, gray relational analysis and spatial analysis functions of GIS) to analyze the relations of temperature variability with topography, latitude and longitude. Moreover, the rank of gray correlation between temperature variability and elevation, longitude, latitude, topographic position and surface roughness also was measured. These results indicated: (1) The elevation affected temperature variability most obviously, followed by latitude, and longitude. The slope of the linear regression between temperature change rate and elevation, latitude and longitude was 0.4142, 0.0293 and -0.3270, respectively. (2) The rank of gray correlation between temperature change rate and geographic factors was elevation > latitude > surface roughness > topographic position > longitude. The gray correlation degree between temperature change rate and elevation was 0.865, followed by latitude with 0.796, and longitude with 0.671. (3) The rate of temperature change enhanced with the increase of elevation. Especially, the warming trend was significant in the plateau and mountain areas of western Sichuan, and mountain and valley areas of southwestern Sichuan (with the warming rate of 0.74℃/10a during the 1990s). However, there was a weak warming trend in Sichuan Basin and its surrounding low mountain and hilly areas. (4) The effects of latitude on temperature change rate presented the specific regulation, which the warming rate of low-latitude areas was more significant than that of high-latitude areas. However, they were consistent with the regulation that the increasing of low temperature controlled most of the warming trend, due to the effects of terrain and elevation on annual mean temperature. (5) Basically, temperature variability along longitude direction resulted from the regular change of elevation along longitude. It was suggested that, in Sichuan-Chongqing Region, special features of temperature variability largely depended on the terrain complexity (e.g., undulations, mutations and roughness). The elevation level controlled only high or low annual mean temperature and the range of temperature change rate in the macro sense.