Abstract:Research on basic theory and its application in Agrometeorology is ernphasized in the United States of America,especially laying stress on energy exchange,water exchange,accumulation and change of matter,models in agricultural production,and interaction between plant and environrnent in the soil-plant-atmosphere system. Reserch is conducted in field condition with advanced data collect system. Neutron probe and lysimeter are widely used in measurement of actual evapotranspiration and used to verify the formulas for calculating evapotranspiration. Many methods calculating potential evapotranspiration are developed from Penman equation and developed computer soft wares to match it. Comparing to other equations,modified Penman-Monteith equation is accurate and used widely.

Abstract:Using of the second experimental observational data,the winter storms over the East Coast of Canada are investigated. The results show that most of them can get explosive development,and the strongest case that has an eye is discussed in detail.

Abstract:The trend surface models to calculate thermal resource in Changbai mountainous region of China were developed. The geographic distribution of the resources were given by using network method. The rational arrangement of the crop varieties were analyzed with the thermal resource condition,and suitable cultural elevation of every variety in every region were calculated. The study has played an important role in agricultural resource exploration of the mountainous region.

Abstract:With weather map,typhoon almanac and satellite images,etc.,the synoptic and climatic characteristics of the tropical storms occuring over western-north Pacific and South China Sea in 1995 are analysed and the reasons for less tropical storms and typhoons their weaker intensity and the difficulty for their tracks forecasts are investigated. The results will benefit both operational forecast and research work.

Abstract:Based on analysis of the feature and evolution of the circulation background,physical quantities,satellite images and surface meso-scale system of the exceedingly heavy rain over Northwest Fujian during 1-3 May 1994,the emergence of the heavy rain and elements feature are described.

Abstract:Based on the data of hail in all parts of China,the melting condition of hailstone from 0℃level to ground,and referring the practical amount of artillery shells used in the hail suppression operation,a new assumption amount of shells is suggested. According to this assumption,a formula to calculate the amount of shells in one hail suppression operation at a site has been deduced.

Abstract:Precipitation enhancement experiment was carried out in Minquan County,Henan Province in two years (1991-1992). The antiaircraft guns firing 37mm AgI shells were used to seed the clouds. The seeded rainfall amount consisted of 48 per cent for a year,71 per cent for summer and 99 per cent for July. The historical rainfall data of the experimental and contral area in 28 years were used to analyse the seeding effect. It was shown that rainfall was increased by seeding for 14per cent (172.2mm) for a year. 31 per cent (188.4mm) for sumrner and 45 per cent (103.8mm) for July.

Abstract:The conductivity and pH value are statistically analysed based on the 557 rainfall samples between 1992 and 1994 at 5 monitoring stations which focus on the observationary station directly belong to Chengdu Meteorological Bureau. And detail analysis under the meteorological conditions is abtained. Results show that annual average pH value in Chengdu is 5.57 and the frequancy of acidrain is 37.4%. The acidrain happens dominantly between July and September,and is related with meteorological conditions.

Abstract:At present,cloudiness observations are of biggererrors. But if the sight of the sky is regarded as hemispheric,the height angle and the width angle of the cloud mass are measured by instruments,and then the cloudiness is calculated by mathematical methods. Then the errors could be decreased. and the precision is greatly increased.

Abstract:The fluctuation of subtropical high of West Pacific during the beginning of the Meiyu period in the middle and lower reaches of Changjiang River have been analysed. It is found that the subtropical high is closely related to the tide-generating forces,either it's set up before the beginning of the Meiyu or it's stable continuation after it. The astronomical criterion is derived to be used for forecasting the beginning of the Meiyu.

Abstract:Based on the daily data in 1993.1-1995.4,correlation analysis of the forecasting of the forest-fire hazard level with the real forest-fire hazard level was studied,the correlation analysis between the forest-fire and the forecasting of the forest-fire hazard level was analysed especially. An accordant result was obtained and some methods were presented to improve the forecasting of the fire weather.

Abstract:Using 38 years hydrometeorological data from 1955 to 1993,the flood peak which water level is higher than 10m is analysed in the valley of the lancang River. The hydroclimate features which caused the flood fatality are given.The forecast method of the flood peak in this reach is suggested.

Abstract:The influence and damage of the severe dry hot weather on orange yield in 1988 are anal ysed. The high ternperature and low moisture are also discussed,and the defence countermeasures are proposed.