Rainfall Pattern Analysis Of Ganxian

Global warming leads to global and regio nal climate change, so that high temperatures, drought, floods and other severe weather-prone, resulting in the deterioration of the ecology and environment, seriously affecting agricultural production, socio-economic and sustainable development. As one of the major grain producing areas in C hina, Jiangxi agricultural production is directly related to our food security. Ganxian is centrally located upstream of Gan River upstream region, it can be well represented in the Gan river of climate change, research precipitation variation Ganxian, contribute to the Gan River Basin water overall resources of the control and overall river basin planning and management, to protect the security of food production provide the basis Jiangxi.Based on the Ganxian C ity 62 years of rainfall observation data in 1951 to 2012, The use of mathematical statistical analysis software SPSS and matlab analysis software is stepwise regression cycle analysis, time series analysis, wavelet canceling noise and Morlet continuous wavelet transform analysis, To study the temporal and spatial variations in the 60 a trends and cycles and through the establishment of rainfall model to predict rainfall in the next few years, the following conclusions:(1)Basing on Ganxian annual rainfall data and assuming cycle factor method, stepwise regression cycle analysis to establish Ganxian rainfall prediction model. Although this method is very old, but it still classic, the advantage of a simple structural model was meaning clear and need little sample prediction accuracy to meet the requirements.(2)Since Ganxian Rainfall randomness is too strong, for a number of difference sequence of correlation, the result is still poor.After superimposing five years of rain to get the new sequence, the new sequence is stationary series which can be the direct modeled. After sample application, the model established by the new sequence can simulate rainfall changes in Ganxian, the prediction error is 7.41%, which was higher forecast accuracy.(3)Ganxian’s Rainfall mainly concentrated in the spring and summer, accounting for 63% of the annual precipitation, the spring and summer precipitation was struck upward trend, autumn and winter trend is not obvious. From the 62 years precipitation cyclical point of view, from the between 1951-2012 and years experienced a total of 5 times of probability of wet and dry alternately, starting in 2010 Ganxian will enter the next the dry period. Frist periodic around 35 a, second cycle is 15 a and third periodic about 2-4a around.Ganxian enjoys comfortable subtropical monsoon climate, During spring and summer period Ganxian influenced by the southeast monsoon, southeast monsoon moisture abundant and frequent changes, so Ganxian will be more precipitation in spring and summer, inter-annual changes in precipitation amplitude, short-term cycle significantly. During Autumn and winter influenced by the Northwest monsoon, the northwest monsoon is airflow drier which come from Siberia, less and stable is trait of Northwest monsoon, inter-annual variation of precipitation rate is relatively small, short-term cycle is not significant. Rainfall concentrated in spring and summer rainfall year, accounting for 33% and 30% respectively. the annual rainfall in the spring and summer by the cycle impact is more obvious. O verall, Ganxian rainfall cycle is relatively stable and there is no singular point.