Based on the data of Chinese PricklyAsh phenological observation and the yield during 1998 - 2007 and meteorological data
during 1961 - 2007, the main influences ofmeteorological conditions on Chinese PricklyAsh growth were analyzed and calculated with
statisticalmethod. The results indicated that the main meteorological factors about Chinese PricklyAsh in Qing’an countywere as fol
lows: the lowest temperature in winter, and temperature daily range, p recip itation, sunshine hours during the full flowering period, the
lowest temperature in the season of flower dropp ing and fruit growing, and the extremely highest temperature and p recip itation in July;
the highest temperature and average temperature in Augest. The freezing injury in early sp ring and drought in July are the main meteor
ological hazards to Chinese Prickly Ash, and their climatic frequencieswere increasing from 2000, thiswould bringmore risk and un
certain factors to Chinese PricklyAsh growth, so the variety cultivation, the soil condition, the cultivation managementmeasure should
be enhanced.

A severe convective storm process occured in the middle of Gansu province on May 30，2005 was analyzed by using CIN·RAD／CC Doppler weather radar data．It is found that the main meso—scale system causing this 8evere convective storm was the squall hne．The storln first appeared at 15：00，then moved to the southeast，and from 16：15 to 17：03 the multi—cell storm became more strongly and developed into the super—cel storm with the characteristics of vortex and zonal echoes．Th ere were two obvious outflow boundaries observed in south of the supercel lying to the southwest and southeast of the hook echo of the storm ，respectively．The shape of the low elevation reflectivity in the left front flank of the superceU was an inverted“V”，the maximum of echo intensity ap-poared in the bounded weak echo zone with the value over 70 dBZ．Th e corresponding radial velocity maps showed a strong mature me·so—cyclone feature．In this period the maximum vertical integrated liquid water(VIL)reached above 70 ks／m and the height of echo top(ET)was 17—18 km．Hence，this storm presented the typical features of superceU storms．

Based on the domestic current researches, the relations between climatic change and Chinese Loess Plateau evolution during the Quaternary arc summarized，and the main characteristics can be listed as follows:① the crucial factors of Loess Plateau formation arc the serial otherness structural variation of Chinese mainland caused by the Himalayan Syntaxes from the "hernary;② during the Pleistocene the strong wind caused by "hibetan Plateau apophysis brings great deal of power一dust from the inland desert in middle Asia zone to Loess Plateau zone, which was formed accordingly;③present monsoon occurred after "hibetan Plateau had reached certain height during the Pleistocene, then the higher of 'hibetan Plateau is, the stronger of the barrier against summer monsoon is.  "hhe warm and wet climate in Loess Plateau turned into cold and drought，and the types and distrbution of vegetation adjusted accordingly;①the adaptability of vegetation could repeat according to climatic changes, namely the
distributing zone moves from north to south on the basis of climatic changes in temperature and precipitation;③during the Pleistocene natural corrosions played great role in soil and water losses in Loess Plateau，and during the Holocene the soil and water losses accelerated because of human activities;⑥soil and water losses in Loess Plateau arc influenced by the geological condition，precipitation,vegetation and human activity, and its spatial variety is obvious.

According to weather and water data，the drought character in upper area of Weihe River and recipitation influence on water resource are analyzed.  The results indicate that annualprecipitation is different but climatic tendency is samefromplace to place，there is 17,13,11 and 3 annual circulationperiod，and water resource is sensible to climate variation，the annualprecipitation change in Mingxian country may cause obvious change in run一off of Weihe River. The stage climatic change do greater harm than the annual climatic change ,perhaps the precipitation over upper area of Weihe River gradually increases in following 20 years.