Study On The Temporal And Spatial Dynamics Of Snow Cover Of Great Xing'an Mountains' Forest Region,Inner Mongolia

This thesis analyzed the relationship between the spatiotemporal dynamics changes of cover snow and changes of temperature,precipitation in the same period,then showed the interrelation between the data from the surface observations and remote sense observations due to the data of Begining and ending date of cover snow,snow duration,cold Season precipitation and temperature from Chinese academic science and 11 surface meteorological observation stations in the northern Great Xing'an Mountains' forest area in past 42 years.The sesults are as follows.1.In past 42 years,the snow cover date gradually came late and gone early in the northern,western and eastern area of the Great Xing'an Mountain and the exactly dates of them are October 6th,October 9th,October 20 th,but in the northern and western area the dates was totally different in 2002,so didn't eastern area in 1988.According to the data from MODIS multi-source remote sensing,the change of the Begining date of cover snow was delayed,the Begining date of cover snow in grassland area was earlier than the forest area.2.The ending dates of snow cover were April 30 th,April 26 th and April 12 th in the next year.The Begining and ending dates of snow cover had no difference between northern area and western area in the past 42 years,but there were significant differences between northern area and eastern area or eastern area and western area.(P<0.05)In the past 42 years,The ending dates of snow cover had no significant difference in western area or eastern area.The dates from northern area was totally different in 1991.According to the data from MODIS multi-source remote sensing,the ending date of cover snow was earlier.3.The variance analysis showed the snow duration in the northern,western and eastern area were obvious different(P<0.05),they were 207.59±14.97 a days,200.23±16.23 b days and 175.29±15.94 c days.It was found that the Begining and ending dates of snow cover and snow duration had a significant correlation with cold season temperature instead of cold season precipitation.(P<0.05)According to the data from MODIS multi-source remote sensing,the snow duration showed the trend of increasing first,then decreasing and keep decreasing from 1980 s to 1990 s and 2000 s till now.4.The average snow depth in Hulunbeier is 4.38 cm according to multi-source remote sensing and the snow depth and snow cover area showed a decreasing trendency.The average reduction is 0.3 cm per decade.There is no significant correlation between the ending date of cover snow in the ground observation data and the date from multi-source remote sensing base on the discussing of coupling relationship.The begining date of cover snow,the snow duration and the snow depth of were all significantly correlated according to the data of multi-source remote sensing(P<0.05).The regression equations of the data of begining and ending date of cover snow,snow duration between the surface observations and remote sense observations were Y=175.934+0.461 X,Y=88.124+0.175 X,Y=52.039+0.589 X.