Spatial-temporal variation of snow cover in the Tianshan Mountains from 2001 to 2015,and its relation to temperature and precipitation
QIN Yan;DING Jianli;ZHAO Qiudong;LIU Yongqiang;MA Yonggang;Muattar Saidi;Xinjiang Common University Key Lab of Smart City and Environmental Simulation/Key Laboratory of Oasis Ecology under Ministry of Education,College of Resources and Environment Sciences,Xinjiang University;Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences;
In this study,the spatial and temporal variation of snowcover in the Tianshan Mountains and its relation to temperature and precipitation were analyzed by using linear tendency estimate and correlation analysis,based on the Moderate Resolution Imaging Spectroradiometer(MODIS) snowcover,MODIS land surface temperature data and China Meteorological Forcing Dataset during 2001-2015. The results demonstrated that:(1)There was obvious difference in monthly distribution of the snowcover percentage(SCP) for different elevation zones; the annual distribution of snowcover percentage presented a unimodal pattern below4 000 m and over5 000 m altitude; the maximum and minimum snowcover percentages occurred in winter and summer below4 000 m,while the maximum and minimum values appeared in summer and winter over 5 000 m,respectively;the seasonal cycle of snowcover percentage exhibited a bimodal distribution between 4 000 m and 5 000 m altitude,with a peak in spring and autumn; during 2001-2015,there was a slight decreasing trend in annual mean snowcover percentage in Tianshan Mountains. However,there were differences in change trend of snowcover percentage in various seasons: there was a slight increasing trend in autumn,while a decreasing trend had been found in other seasons with more obvious in winter and summer.(2) The snowcover frequency(SCF) presented a spatial pattern from west high to east lowand north high to south lowdue to water vapor sources and topography,and showed a positive correlation with elevation; the SCF had showed a decreasing trend during 2001-2015 in the Tianshan Mountains with more obvious in the altitude range between 3 600 m and 4 600 m.(3) In spring and summer,the temperature was the main cause of the change of snowcover percentage,and showed a negative correlation with snow; while in autumn and winter,precipitation was the main cause of the snowchange,and had a positive correlation with snow.(4) Overall,the snowcover frequency showed a negative correlation with annual mean temperature and a positive correlation with precipitation; although there were great spatial differences in the degree of correlation and the significance level,the impact of temperature was larger than that of precipitation on SCF change.
【Fund】： 国家自然科学基金项目(41771470;41730751;41771087);; 新疆维吾尔自治区重点实验室专项基金项目(2016D03001);; 自治区科技支疆项目(201591101);; 教育部促进与美大地区科研合作与高层次人才培养项目资助
【CateGory Index】： P426.635
【CateGory Index】： P426.635