The relation between the area of potato late blight and weather conditions in Chengde city during 1990 - 2008 was analyzed.It shows that the biological factor p lays a role under suitable weather conditions in the occurrence of potato late blight. Weather conditions such as temperature, p recip itation, relative humidity, sunshine hours are decisive factors for p revalence of potato late blight. The app rop riate temperature, rainy or foggy weather are most conducive to late blight occurrence and p revalence. Using the affected rate as a criteria to classifymeteorological levels for potato late blight, we selected the p recedingmeteorological elementswhich related well to potato late blight as a p rediction factor, then establish the meteorological forecastingmodel using integrated clusteringmethod. Test results showed that the model can imp rove decision - makingmeteorological service level and win time to control the sp read of potato late blight.

Abstract: The correlation between groundwater funnel and annual p recip itation in Langfang, Hebei Province was analyzed in this article. Results show that overexp loitation of groundwater triggered by meteorological drought further aggravated hydrological drought, the groundwater funnel and land subsidence disasters. In the time series, the meteorological drought p resents the wavelike characteristic,while the groundwater funnel and the surface subsidence disp lay the slow develop ing, cumulative and irreversibility characteristics, thustemporal termination of meteorological drought cannot p revent the groundwater funnel and the surface subsidence development and sp read. At the same time, some countermeasures such as reasonable exp loitation of groundwater, re - use of water resource, development of water - saving agriculture are p roposed.

Based on the conventional data, satellite cloud images and Dopp ler Radar data, the snow storm weather occurred in sp ring of
2007 in Chengde was analyzed from the large - scale background, water vapor and dynamic conditions. The results indicate that the
block from the eastern p ressure ridge leads to themerger and intensification of the north and the south low - p ressure systems, andmov2
ing slowly of the low - p ressure system results in this storm event. The convergence in the lower level and the foundation of low level jet
made large - scale water vapor convergence and continualwater vapor transmission, and the deep - thick atmosphere wet layer p rovides
a favourable surrounding condition and the divergence, vertical velocity and k - helicity fields are dynamic conditions for this heavy rain.