Changing Characteristics Of Snowfall In Xinjiang From1961to2010

Snow is the solid-state form of precipitation. Xinjiang is located in the northwest aridareas. Snow is beneficial to relieve the drought in this area, but heavy snow also causedserious natural disasters. Based on the data in1961~2010in Xinjiang snow, this papersystematically analyses the variation characteristics of snow in this area. Based on theanalysis of the spatial and temporal variation characteristics of snow in Xinjiang, theXinjiang change characteristics of precipitation concentration degree and concentrationperiod and the change characteristics of snowfall days, and then analysis the changingcharacteristics of the different levels of snow and the change characteristics ofcorresponding snowfall days, at the same time to snow, snow days, big blizzard days futuretrends predicted. In this study the following main conclusions:(1)Snow is on the rise and passed the test of significance of95%. There is obviousperiodic change. Northern of Xinjiang and Tianshan mountains is on rise significantlygreater than the southern of Xinjiang. Snowfall increases gradually from south to north inXinjiang. The snowfall in the northern of Xinjiang and Tianshan mountainous area isbigger than the southern, and has a gradually decrease trend from the west to the east.(2)The snowfall’s PCD has increased, and gradually concentrated in southern ofXinjiang and north of Xinjiang, but is not concentrated in Tianshan mountains. The biggestsnowfall in south Xinjing region appears in the middle of December until the middle ofJanuary the following year, the north’s biggest snowfall is in more in late December and thefollowing year in late January, and Tianshan mountainous area biggest snowfall is in moreearly December to the middle of march the following year. Snowfall’s PCP has roughly atrend of decreasing from west to east. The biggest snowfall is in early January to earlymarch in western of Xinjiang and is in late November to mid-January next year in easternof Xinjiang.(3)Snowfall day increased year by year in Xinjiang region, and northern of Xinjiangarea is the most, southern of Xinjiang region is minimum. Snowfall day has11years ofshort cycles and20years of change for a long period of time. Snowfall day increasesgradually from the south to the north, northern of Xinjiang area is bigger than the snowfallday southern region. Snowfall days tended to rate increase gradually from south to north,roughly, but around the trend rate of difference is not obvious. (4)All levels snowfall are on the rise in Xinjiang, but the amount of light snow upwardtrend is not significant, moderate snow and a big amount rise significantly, all levelssnowfall shall increase gradually from south to north on the space distribution. Light snowcontribution is on the decline, moderate snow contribution ratio is on the rise, and the greatblizzard space light snow contribution rate gradually reduces from the south to the north,and moderate snow contribution rate and the great blizzard contribution rate increasedgradually. Light snow contribution rate and negatively correlated with snowfall, snowcontribution rate was positively related with snow. Snowfall days at various levels haveincreased, but the light snow and moderate snow days trend is not obvious, the greatblizzard days rise significantly. Snowfall days at all levels of distribution has the similarity,increase gradually from the south to the north, and roughly a dusting of snow dayssignificantly greater than moderate snow days and big blizzard days, big blizzard daysappeared several high value center, is the high rates of snow disaster area.(5)By using R/S analysis of Xinjiang region snow, snow days, big blizzard days seriesH index, the results showed that the sequences of Xinjiang, southern Xinjiang, northernXinjiang, Tianshan have the long-term correlation, namely the future changes will changetrend is consistent with the past. According to the instruction from the Hurst index meaningcan be concluded that the future changing trends of Xinjiang region snow, snow days, bigblizzard days as the same as the past50a, will continue to rise, and persistent strength isquite large.