Global Warming, The Environment In Northern Shaanxi, Guanzhong And South Shaanxi Comparative Study Of Climate Change

The study of the climate change is always be concerned by some scholars,however,nowadays in China,with a series of problems occurring in the development of economy,such as climate warming,arid,the growth of storms and torrents,which resulting from the increased greenhouse gases,the scholars even the government,again focusing on the climate change.The paper, based on month average temperature and month precipitation of twenty-seven meteorological stations in Shaanxi province, Using the methods of correlation analysis, the cumulative anomaly, trend analysis, coefficient of variation, wavelet analysis, Mann-Kendall testing and geostatistical analysis (through ArcGIS for data interpolation), under the background of global climate warming,according to the temporal and spatial change,studies the overall changes of annual average temperature and annual precipitation in Shaanxi province,along with the seasonal temperature and seasonal precipitation in Shanbei,Guanzhong and Shannan of Shaanxi province,expecting to identify the responses of regional climate change to global climatic change.About temperature:temporal,(1)the annual average temperature of Shaanxi province has a ascending trend.and the rate is 0.208℃/10a,what's more,from north to south the increasing rate of temperature became smaller.Seasonally,there are consistency between the province and three parts of it, that is the winter is the biggest contribution, the summer is the smallest and even has a descending trend in temperature.Regionally,the consistency between Northern and Guanzhong is higher than that in Southern area;In summer temperature,both Guanzhong and Southern have a colding signal.(2)About the periodical analysis of annual average temperature among Northern,Guanzhong,Southern and the province,there are approximately sixteen or seventeen years of phasic changes of warm and cold alternating in the scale of thirty-five years. It is in the middle of 1990s that the abrupt change occurred amongNorthern,Guanzhong,Southern and the province, that is the Northern is ahead about 2-3years of the province,while Guanzhong is in synchronisation with the province,Southem is delayed about1years,however,whether in Northern, in Guanzhong,in Southern or in the province, all occurred the mutation from low temperature to high, which is the same.(3)About spatiality:overall,the annual average temperature, from northern,Guanzhong to southern,is increasing ascend,the high-temperature center in the south, while the low center in the north which within western side. Regionally, the annual average temperature in Northern is far lower than that in the province,while the annual average temperature in Sorthern is far higher,and there are quite different spatial distribution of temperature in Guanzhong area.About temperature tendency rate:as far as the province is concerned, most of the annual average temperature has an increase trend;Regionally,the biggest change multitude of annual average temperature is in Northern,followed by Guanzhong and northwest of Southern,east and south of Southern are the smallest,further in the center of shangnan county (the tendency rate is-0.006℃/10a) and nearby even has a slightly cooling trend,from north to south,the temperature increased rate is gradually decreased.Coefficient of variation (Cv):The coefficient of variation can reflect the fluctuations of annual average temperature over time, the trend that the value of the cv of the province showed that along the latitude from south to north and along the longitude from east to west is gradual become large, which reflects the temperature change under the role of the latitudes and the longitudes.But regionally, the cv vary widely within regions of the province.About precipitation:temporal(1)there is a decreasing trend(with the rate of-11.19 mm/10a) in Shaanxi province from1960to 2009,and the amplitude of it is Northern the biggest,followed by Guanzhong,the Southern.As far as the annual is concerned,the province and the three areas have a consistency in precipitation,that's showed a reducing tendency, and have a similarity in amplitude,which the reduction of precipitation is mainly attribute to the precipitation in spring and autumn. Seasonally,Spring,autumn,winter and the annual precipitation have a similar trend and all are increase in spring and autumn while less in winter, but there is a great range of differences within regions.As for the decadal changes, the precipitation in the province, in northern, guanzhong and southern all have emerged fluctuations, nevertheless, the magnitude of fluctuations and times are different. (2)About the periodical analysis of annual precipitation among Northern,Guanzhong,Southern and the province,there are about sixteen or seventeen years of phasic changes of warm-cold alternating in the scale of thirty-five years.In addition, there are 5-7 years of small-scale cycle in Northern; About the annual precipitation in Shaanxi, Guanzhong and southern there also exist on 5 scale oscillations in 20-year scale, what's more,it also exist in ranging from 5,7,10and13 etc small-scale cyclical changes.(3)Spatiality:The spatial distribution of precipitation in Northern,guanzhong and Southern has a great disparity,it Shows a reducing tendency from south to north;Regionally,the annual precipitation shows the order of northern,guanzhong,southern,at the same time,there are great differences within regions.Concerning the tendency ratio of precipitation:there is an obvious decreasing signal as time go on,and the area disparity kg is large.Regionally,except the Dingbian county (with the rate of 1.82mm/10a) and the Hancheng (with the rate of 3.08mm/10a) have a positive tendency rate,other else display a reducing trend in precipitation.There are two opposite extremes in Southern,where the maximum positive value and the maximum minus value occurred.As a whole, in nearly 50 years in northern and Guanzhong there is a decreasing trend in precipitation, even southeast in Northern and west in Guanzhong have a more significant reduction, thus Guanzhong, Northern occurred warming and drying trend; The temperature in Southern rise, while the precipitation has occurred a two contrary trends—increase and decrease. With regard to the coefficient of variation:On the whole, the cv of annual precipitation along the latitude and longitude shows a growing trend, indicating that the inter-annual fluctuation of precipitation increased violately. Regionally, the cv of annual precipitation obeys the order of Northern>Guanzhong> Southern, and the value in Northern higher and in southern lower than that in the provincial average,whilst Guanzhong has a similarity with the provincial average, but there are significant differences within each region.The correlation between temperature and precipitation:as far as the season is concerned, in the summer,the temperature is best correlated with precipitation, the whole province, Guanzhong and Shannan all have reached a highly significant level, and thecorrelation coefficient respectively, the largest one is Guanzhong, the province is the smallest, the middle one is Shannan, indicating that as the temperature rise,the precipitation showed a decreasing trend, thus forming of the warming-drying trend.lt is the winter that the correlation between temperature and precipitation is worst, the relationship between precipitation and temperature is not obvious. Regionally:the correlation between temperature and precipitation is of the best in Guanzhong region(the correlation between temperature and precipitation in annual, spring, summer and autumn have reached a highly significant level), followed by the province and southern Shaanxi (temperature and precipitation in annual, spring and summer have reached a evident level), Northern was the worst at all(only in summer the correlation between the temperature and precipitation reached a significant level).