The study took advantage of the theory of Regionalized Variables, found out the semi-variogram suitable for TIA, and reviewed the rationality of the ombrometer network. After compared with the original system,we suggested that Shan-jiao, Gan-yuan, and Sha-lun stations should upgrade the ombrometers to an automatic system.Therefore we could improve the stability of the semi-variogram, and improve the accuracy of the estimate of rainfall.