Analysis Of Vegetation Dynamic Changes And Influencing Factors In Altay Region In The Past 20 Years

Vegetation as the main part of the ecosystem,is one of the important signs of regional ecological environment.Due to the common impact of various factors such as natural factors and human activities,vegetation coverage changes are complex,analyze vegetation coverage in detail in the regional scale and its response to climate,terrain,etc.,has become a hot problem in the field of ecological environment.one.Altay region is rich in natural resources,ecosystem complex and diverse,is the main city of Xinjiang,Mongolian,and Russian economy corridors,but the ecology of Altai region is extremely sensitive and fragile,and the ecological environment is increasingly concerned.It is therefore conducting research on the characteristics of time and space change in Vegetation coverage in Altai,which helps to explore the driving factors of vegetation dynamic changes,which has important application value and practical significance for the ecological environment in Altai.Using NDVI,LAI,GPP,SPEI and other multi-source remote incentive time series data,use trend analysis algorithm,terrain bit and GIS statistical analysis algorithm,and study vegetation coverage in the past 20 years in the past 20 years.Combined with the precipitation,temperature data,the related analysis method is used to analyze the relationship between dynamic changes and precipitation and temperature from the two angles from the annex and season.At the same time,the advantageous terrain of the vegetation change type of the study area was analyzed by the terrain factor such as the altitude,slope and slope of the study area.The main conclusions of this article are as follows:(1)Based on the MODIS NDVI time series data from 2000 to 2019,after projection transformation and image splicing processing by the MRT tool,the pixel two-point model has been extracted for 20 years of vegetation coverage time sequence,and then based on one-unit linearity The trend returnsioned algorithm carried out dynamic analysis of vegetation coverage in Altai area,and got a trend chart of vegetation coverage in the 20 years of the study area.Combined with the NDVI,LAI and GPP_VPMdata in the study area.During the study,the annual NDVI,LAI and GPP_VPMvalues showed a change in the decreased increase,of which 2008 is a low valley(lowest point)position.Combined with SPEI data analysis,the study area has been a decline in drought conditions in 2008,and multi-source remote sensing data in 2000-2008 in 2008.After 2011,although SPEI presented varying degrees of fluctuations,NDVI,LAI,GPP_VPMdid not have a certain rise in the influence of the drought,reflecting the ecological protection policy of the study area plays a forward role in vegetation changes.(2)Trend graphs of NDVI and LAI based on trend analysis algorithms,analysis found that NDVI and LAI spatial change trend is basically consistent during research,and present a certain spatial difference,where vegetation is restored.Mainly near Altai Mountain and Urrogue and Rivers,combined with the day map image,Google Historical image,etc.Further analysis found that the region is mainly agricultural area,affected by the Wushu water and the upstream ice and snow water in Urban,and the vegetation growth trend.Faithful;the vegetation degradation area is located in the southern desert area in the study area,mainly affected by factors such as climate environment and human interference,and vegetation exhibits a certain degree of degradation.(3)Further combination of vegetation coverage trend and terrain distribution analysis found that from terrain factors,the vegetation distribution is mainly located in areas less than1500m,and the advantages of less than 600m elevated area vegetation improvement are most significant,at sea level than 2400m area The degradation of vegetation is more obvious;the slope is analyzed,the vegetation improvement is distributed in the three slopes of Pinghop,South slope,and the western western slope.It is the main distribution of vegetation stable advantages,and the vegetation degradation is mainly distributed in Dongpo and South.slope.The statistical distribution area has found that the moisture slope is significantly greater than the slope;growth in the slope is a more significant advantageous distribution in the slope of the slope,and the degradation advantage is more obvious in the high slope.(4)From the analysis of climatic factors,NDVI is shown in various quarters and growth season(4 to September)and precipitation,and the temperature is shown as mutual inhibitory and mutual promotion.The correlation between NDVI and meteorological factors in different seasons has a significant seasonal difference,and vegetation growth is positively related to precipitation in summer and growth season.It is positively related to the temperature in spring,and the highest correlation between NDVI and meteorological factors in autumn.Positive correlation,negatively correlated with rainfall.