The Analysis Of Meteorological Drought Rules In The Eastern Agricultural Areas Of Qinghai Province

In this paper, the eastern agricultural areas of Qinghai research achievements of droughtcombined with the probability distribution of meteorological elements, the use of run-lengththeory, the theory of negative wheel changes,and Markov chain theory discussed Fengkudifferent precipitation sequence, studied low meteorological droughts in the region; Withweighted Markov chain model theory, we constructed a model to predict precipitation in theeastern agricultural areas of Qinghai Province, the annual precipitation state forecasting its13weather stations. In this study, the main results obtained are as follows:(1)The calculation was based on Thiessen polygon surface of the agricultural area ineastern Qinghai Province precipitation is417.74mm.With low amount of precipitation,flatamount of precipitation and high amount of precipitation analysis of three levels ofprecipitation in the study area occurred,Wet slightly lower than the frequency of occurrencefrequency less water, alternating droughts and floods, the water level of flat water was theminimum frequency of cases, occurred once every four years; to dry, dried up, flat water,overabundant and abundance analysis of five levels of precipitation in the study area aremostly dried up, with an average of3.2years occur once; each station variation coefficient Cvwas from0.13to0.24, in addition to the Ledu stand extreme than3.40greater, the reststations are similar at2.0, then the the eastern agricultural areas of Qinghai precipitation littlechanged.(2) The Probability analysis of several low or high amount of precipitation showed thatthe frequency of less water appeared greater than the frequency of water;one-year low amountprecipitation took place with the frequency of0.74which was higher than one-year highamount of precipitation.2-year and more than2-years low amount of precipitation took placewith the frequency which was higher than more than2-year and2-years high amount ofprecipitation.(3) The consecutive years of high amount group were between2.14and3.12years, themean was2.52years.the probability of consecutive year high amount was lower thanconsecutive year low amount,which showed thatthe case of low amount of precipitation in theeastern agricultural areas of Qinghai was easy to take place. (4) Steady state analysis showed that the mainstream status in the eastern agriculturalareas of Qinghai was partial low flow year; according to the theory of negative round weremostly in2,3years,the longest period of less water accounted for the proportion of14.52%~39.86%to annual mean precipitation,The maximum annual amount of wateraccounts for about48.51%~26.8%to annual mean precipitation,which showed that theeastern agricultural areas of Qinghai was easy to threated by drought and there was a droughtoceurred in less than2years.(5) Weighted Markov model predicted results were not specific values but the state(interval value) of the precipitation with the results of high reliability and relatively simplemethod.The weather forceasting model of13stations of the eastern agricultural areas ofQinghai was built,which was tested with a more satisfactory fitting accuraey,and it can be putinto practice.Its predict results showed that precipitation in the study area in2007was stable.The purpose of disaster forecasting is to relieve and prevent drought, this paper analyzedthe causes and effects of drought in the eastern agricultural areas of Qinghai Province, and putforward some countermeasures to solve the problem of water shortage and drought relief:useof rainwater catchment, catchment irrigation mode.