Changing Tendency and Multi-Scale Features of Precipitation in the North Source Area and Mainstream Area of the Tarim River
LI Xue-mei1,2,JIANG Feng-qing1,LI Lan-hai1,WANG Gui-gang1,2,WEI Bing-gan1,2,(1. Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,rmqi Xinjiang 830011,China;2. Graduate University of Chinese Academy of Sciences,Beijing 100049,China)
As a part of the Tarim Basin,the north source area and trunk area of the Tarim River is the major eco-agriculture area in the southern part of Xinjiang Uygur Autonomous Region. In the end of the last century,a lot of ecological and environmental issues,e.g.,shortage of the water resources,shrinkage of the forest area,and dried up of the end lake,etc.,occurred in the areas. Recently,these issues have attracted serious attention of scholars,local people and government officials. It is believed that these issues are results of partly changes in climatic and hydrological situation and especially enhancement of local human activities. Many research works have been conducted on climate change and its impacts on local eco-environment. However,they only focused on the precipitation and temperature changes in the whole Tarim Basin. More detailed information about the multi-scale characteristics of precipitation variation in a smaller area,especially in the source area of the Tarim River,has not been thoroughly studied based on robust analysis methods. What mentioned above is the main motivation of the present research. In this paper,the variation of annual precipitation is analyzed by using simple linear regression,smoothing method and Morlet wavelet power spectrum analysis,based on annual precipitation data from 1959 to 2004 observed at twelve meteorological stations,i.e.,Aheqi,Baicheng,Akesu,Alaer,Bayinbuluke,Baluntai,Luntai,Yanqi,Kuche,Kuerle,Tieganlike,Ruoqiang in the north source area and trunk area of the Tarim River,in which the first nine stations represent the region of the north source area and the rest represent the trunk area of the river. Simple linear regression and smoothing method are used to describe the changing tendency of annual precipitation,and the Morlet wavelet power spectrum analysis is used to detect the characteristics of cycles in precipitation in the two areas. The results show that annual precipitation of the two areas has increased since 1986,which may be an indicator of the turning of climate change from dry-warming to wet-warming in Xinjiang Region. The annual precipitation in seven stations in the north source area has increased remarkably,and the increase of annual precipitation in two stations in the trunk area of the river is significant. The detected significant cycles are concentrated within the band of 2~8-year. Most of the stations have about 2~4 year inter-decadal cycles in annual precipitation in the north source area dispersedly. Whereas,a rough 3-year cycle is the main one in the trunk area of the river. Meanwhile,a rough 16-year,a rough 32-year cycle and others in the decadal scale are found in precipitation in some selected stations,but they are not significant at a significance level of 0.05 owing to the limit of the length of time series or uncertainty. The results of this study will be helpful for further studying climate change in Xinjiang Region and for developing and managing local water resources.
【Fund】： 国家科技支撑计划“西北生态脆弱区适应气候变化技术示范”项目(2007BAC03A0604);; 中国科学院新疆生态与地理研究所“绿洲学者”计划项目;; “塔里木河干流生态水文过程及其对气候波动的多尺度效应”项目(40871027)资助
【CateGory Index】： P426.614
【CateGory Index】： P426.614