Based on the conventional observations andNCEP reanalysis data, the two similar storm cases occurred on June 30 and July 21, 2008 in Longnan disaster areawere diagnosed. The analytic conclusions are as follows: The shearing low vortexwas themain influence system of“6. 30”heavy rainfal,l but less ascendingmotion resulted in less stations’s precipitation up to 50 mm. The plateau low vortexwas themain influence system of“7. 21”storm rainfal,l because ofbettervapor condition and strong vertical ascendingmotion,the precipitation in 50 percent stations ofLongnan region wasmore than 50 mm during“7. 21”storm rainfal.l The relation is in evidence between the loss from heavy rainfall disaster and the center area of rainfall

By using wheat red mites data and meteorological data in Longnan mountainous area of Gansu Province from 1992 to 2005,
the wheat red mites appearing circs are investigated and analyzed. The main results are as follows: There are two main kinds ofwheat
red mites there, namely Penthaleusmajor ( duges) and Petrobia latens (mullen) , which appeared mainly from February to Ap ril each
year. Because ofwheat red mite’s harm, wheat yield is reduced about 10% in the area of 66 670 hm² each year. There is a positive
correlation between the wheat red mite p robability and monthlymean temperature from Sep tember toMarch, but for p recip itation during
that period it p resented remarkable negative correlation, with respect to the period from Ap ril to August, there is a negative correlation
formonthlymean temperature but positive correlation for p recip itation. Finally the p rediction model of wheat red mites appearing in
Longnan mountainous area is established in terms of agricultural meteorology, and the p robability of accuracy is 100% in 2006 and
2007’s operation p redictions.