GEOGRAPHICAL RESEARCH ›› 2011, Vol. 30 ›› Issue (7): 1237-1243.doi: 10.11821/yj2011070009

• Earth Surface Processes • Previous Articles     Next Articles

The influence of gauge density on the interpolation of critical and antecedent effective precipitation that triggered the debris flow

ZHANG Guo-ping, CHAO Yuan, XU Feng-wen, ZHAO Lin-na   

  1. Public Weather Service Center of CMA, Beijing 100081, China
  • Received:2010-08-02 Revised:2010-11-29 Online:2011-07-20 Published:2011-07-20

Abstract: It is important to understand the effect of the rain gauge density on the interpolation of effective antecedent precipitation and critical rainfall. For the 87 debris flow sites, the interpolation rainfall is calculated based on 5%-100% variational sampling scheme of 207 rain gauge stations. The inverse distance weight method is used to interpolate the effective antecedent precipitation and critical rainfall. Using the quantiles method, the relationship between the gauge density and the interpolation rainfall of the day debris flow and the effective antecedent precipitation is analyzed. The result shows the interpolation rainfall is exponentially decreasing due to the decrease of the gauge density. The interpolation of the effective antecedent precipitation is more stable and needs smaller amount of gauge with the same precision than that of the critical precipitation. When the gauge density is less than 5%, the interpolation of the effective antecedent precipitation keeps the real value beyond 60%, otherwise the critical rainfall is under 30%.

Key words: gauge density, precipitation interpolation, debris flow, antecedent effective precipitation, critical precipitation