A Study Of Precipitation Characteristics In The Badain Juran Desert And Tengger Desert

Desert contains rich resources which have an important influence about human activity, there are many important facilities related to national construction. Precipitation destruction of essential facilities should not be underestimated. In this study, the characteristics of space-time distribution of precipitation on The Badain Jaran desert and Tengger desert are analyzed by using 0.1° x 0.1° hourly merged precipitation data during 2008-2013.Use the merged precipitation data divides the precipitation levels,and analyze the precipitation levels’ characteristics of space-time. Analyzed the advantages of the hourly merged precipitation data on study desert’s precipitation by contrast with surrounding The Badain Jaran desert and Tengger desert meteorological station precipitation data. Analyzed rainfall annual change trend with surrounding The Badain Jaran desert and Tengger desert meteorological station precipitation data by using a new data analysis method-ESMD. The major results are as follows:(1) The precipitation average annual change is nonlinear in surrounding area of Badain Jaran and Tengger Desert. Use a new data decomposition method—ESMD, get the 1960—2014 average annual rainfall time series modal component and globally adaptive curve, which can better describe the nonlinear variation of the average annual rainfall in surrounding area of desert.(2) The hourly merged precipitation data more can reflect distribution of precipitation in the desert compared with the interpolation result of precipitation data,which from The Badain Jaran desert and Tengger desert surrounding meteorological station. Under some weather conditions, the surrounding desert meteorological observatory without precipitation cannot reflect no precipitation in the desert, especially in desert hinterland. When heavy rain appeared, the hourly merged precipitation data can be very good analysis the details of the whole regional precipitation in desert areas.(3) The precipitation in the Badain Jaran and Tengger deserts focused on May to September and got highest in July,while was less in other months and not covered. In June and July, the mean precipitation grid of Badain Jaran Desert area is higher than the Tengger Desert region, and in other months, the mean precipitation grid of Tengger Desert is higher than the Badain Jaran Desert.(4) In winter, the precipitation has small grades. the peak of The Badain Jaran desert and Tengger desert’s precipitation diurnal variation appeared in 06 am. In spring, the daily precipitation peak appeared in 04 am on The Badain Jaran desert and in 00 am on The Tengger desert; while the precipitation get higher level than winter’s. Summer in the desert’s rainy season, precipitation diurnal variation of the Badain Jaran Desert area is bimodal, the main peak value appeared in 04 am,the second peak appeared in 4pm.The Tengger desert precipitation amplitude of variation is small, but have a higher level. In autumn, precipitation diurnal variation of the Badain Jaran Desert area is unimodal, the peak value appeared in 3pm. Precipitation diurnal variation of the Tengger Desert area is bimodal, the main peak value appeared in 1pm,the second peak appeared in 11 pm.(5) The average annual number of days without precipitation in the Badain Jaran Desert and Tengger Desert area accounted for more than 75% of the total days.The main precipitation frequency of The Badain Jaran desert and Tengger desert area is 0.1-1 ㎜ which is weak precipitation event. Weak precipitation events in Badain Jaran desert region accounted for 54.7% of total precipitation days while Tengger Desert accounted for 60.1%. Badain Jaran Desert and Tengger Desert precipitation events over 20 mm precipitation days only 2.2%.