| As one of the most active factors in terrestrial ecosystem,vegetation is a good indicator of ecosystem change.In recent years,the climate fluctuation in Liaoning province is obvious.It is very important to study the relationship between vegetation and climate.Taking into account the previous few comprehensive and in-depth analysis of Liaoning province vegetation dynamic evolution and climate driven effects,based on the remote sensing image data MODIS-NDVI,the statistical analysis method combined with GIS technology based on the in-depth study of dynamic evolution process of vegetation in the study area,and select the temperature,precipitation,sunshine duration and effective accumulated temperature above 10 DEG C,identify the climatic driving factors of vegetation dynamic evolution,research the effect of human activities may cause,provide theoretical support for the region to carry out the quality assessment of ecological environment,ecological security etc..The main conclusions are as follows:(1)NDVI in Liaoning province on the interannual scale showed obvious increasing trend and marked mutation in 2005,average NDVI is 0.496;in the spring,summer,autumn and the vegetation growing season NDVI mutation year respectively for 2006,2005,2009 and 2004.The change of autumn fluctuation is obviously lagging.The fine vegetation coverage is consistent with the boundary of the eastern hilly area of Liaoning province.Poor vegetation cover areas are mainly concentrated in Chaoyang City and Fuxin city in Liaoning province;Vegetation coverage overall to maintain the status quo and slight improvement,remain concentrated in the eastern region,Liaoyang city and Shenyang city with a slight degradation.The improvement of vegetation coverage is more obvious in the northwest of Liaoning Province.(2)During the study period,the mean annual temperature fluctuation is significant but overall downward trend is not obvious in Liaoning province.The annual precipitation increased significantly,the overall trend of annual sunshine time variation is not obvious,the overall decline in the average temperature trend compared to accumulated temperature is more obvious;The highest temperature in the growing season of the vegetation was synchronized with the summer,but early in the spring and autumn two seasons.The temperature and accumulated temperature show a pattern of gradual warming from the northeast to the south of Liaoning province.The precipitation decreased gradually from southeast to northwest,and the seasonal difference was not significant.The spatial distribution pattern of sunshine duration is just opposite to that of precipitation.(3)During the study period,the temperature and accumulated temperature were negatively correlated with vegetation NDVI,while precipitation and sunshine hours showed a positive correlation.The main effect of May in the eastern part of Liaoning province vegetation growth factor is the temperature and sunshine hours,the western region is the precipitation;The main factor affecting the precipitation and sunshine duration in June to August,the main influence factors to the growth of vegetation in September is the temperature and sunshine hours;The change of temperature on the growth of vegetation is most sensitive and most slow response to sunshine.The impact of human activities on vegetation growth also played an important role,Liaoning province SLCP outstanding work,afforestation also obtained thorough development.Although the occupation of land occupied some of the arable land,woodland,etc.,but the intensity of urban greening has been increasing,which is also a part of the factors leading to the improvement of vegetation coverage in Liaoning province. |
