Journal of Geographical Sciences ›› 2005, Vol. 15 ›› Issue (2): 223-238.doi: 10.1360/gs050211

• Climate and Environmental Change • Previous Articles     Next Articles

The SIA method for spatial analysis of precipitation in the upper-middle reaches of the Yangtze River

ZHOU Suoquan1, XUE Genyuan1,2, GONG Peng3, CHEN Jingming3, ZHANG Hongping4, ZHOU Zhijiang5, FAN Xiong6, DENG Xiaochun7, WU Zhanping8   

  1. 1. Key Lab of Meteorological Calamity, Nanjing Inst. of Meteorology, Nanjing 210044, China;

    2. Meteorological Bureau of Zhejiang Province, Hangzhou 310002, China;

    3. The Earth Science System Institute, Nanjing University, Nanjing 210093, China;

    4. Meteorological Bureau of Shaanxi Province, Xi'an 710015, China;

    5. Climate Research Centre, China Meteorological Administration, Beijing 100081, China;

    6. Meteorological Bureau of Sichuan Province, Chengdu 610001, China;

    7. Meteorological Bureau of Hunan Province, Changsha 410001, China;

    8. Meteorological Bureau of Guizhou Province, Guiyang 550001, China
  • Received:2004-11-04 Revised:2005-01-25 Online:2005-06-25 Published:2005-06-25
  • Supported by:

    The National 973 Project of China, No.2001CB309404; Oversea Outstanding Youth Cooperation Project, No.40128001/D05; National Natural Science Foundation of China, No.49375248; Zhejiang Province Science Research (C33) Project, No.2004C33082


Using geographic information system (GIS) techniques and the newest seasonal and annual average precipitation data of 679 meteorological stations from 1971 to 2000, the multiple regressions equations of the precipitation and topographical variables are established to extract the effect of topography on the annual and seasonal precipitation in the upper-middle reaches of the Yangtze River. Then, this paper uses a successive interpolation approach (SIA), which combines GIS techniques with the multiple regressions, to improve the accuracy of the spatial interpolation of annual and seasonal rainfall. The results are very satisfactory in the case of seasonal rainfall, with the relative error of 6.86%, the absolute error of 13.07 mm, the average coefficient of variation of 0.070, and the correlation coefficient of 0.9675; in the case of annual precipitation, with the relative error of 7.34%, the absolute error of 72.1 mm, the average coefficient of variation of 0.092, and the correlation coefficient of 0.9605. The analyses of annual mean precipitation show that the SIA calculation of 3-5 steps considerably improves the interpolation accuracy, decreasing the absolute error from 211.0 mm to 62.4 mm, the relative error from 20.74% to 5.97%, the coefficient of variation from 0.2312 to 0.0761, and increasing the correlation coefficient from 0.5467 to 0.9619. The SIA iterative results after 50 steps identically converge to the observed precipitation.

Key words: the upper-middle reaches of the Yangtze River, precipitation resource, spatial analysis, successive interpolation approach (SIA)