Dynamic Change Of Vegetation And Phenology Response To Climate Change In Hubei Province

In recent years,the phenomenon of global warming is more and more serious,a series of environmental events caused byclimate change have become an urgent problem in the sustainable development of human society.Vegetation regulates energy conversion,carbon cycling,and climate change in the biosphere through photosynthesis,surface reflectivity,and roughness.Understanding the relationship between vegetation and climate variables from different spatial and temporal scales can not only predict the future growth trend of vegetation,but also reveal the response mechanism of vegetation to climate change.Based on the meteorological data of Hubei Province from 1982 to 2015,the temporal and spatial trend of climate in Hubei Province was analyzed in the past 34 years.In addition to,we analyzed the NDVI time variation law of Hubei Province in recent 34 years under the influence of climate warming based on the long-term GIMMS NDVI3g remote sensing data.At the same time,the surface phenological parameters were retrieved by time series harmonic analysis in GIS and Matlab platform.Based on the Sen trend method and the first linear regression trend method,the surface phenology parameters of vegetation and different vegetation types in Hubei Province were quantitatively described from the perspective of spatial and temporal And the mechanism of surface vegetation coverage NDVI and surface phenological parameters on the main climatic factors in the study area are further elucidated.Exploring the temporal and spatial coupling relationship between vegetation cover and climate change in Hubei Province is conducive to fully understanding the impact of climate change on the dynamic changes of local vegetation,providing a favorable scientific basis for local natural resource utilization and protection,and enhancing the ability to adapt and mitigate climate change Also has an important guiding role.The main conclusions as follow:(1)During the period from 1982 to 2015,the average temperature in Hubei Province showed a gradual increase trend,and the increasing trend of temperature in central,southern and northeastern of Hubei was significantly faster than that in other regions.While the annual precipitation in Hubei Province showed a decreasing trend,and only the precipitation in Zhuxi County,Zhushan County and Jingzhou City in the western part of Hubei Province showed an increasing trend.(2)The spatial distribution of NDVI in Hubei Province from 1982 to 2015 was mainly due to the increasing trend from east to west,and the trend of overall change was mainly increased,but the rate of NDVI rose in the 1980s and 1990s was relatively low.The NDVI of the spring?summer and autumn showed an increasing trend,and the NDVI showed a decreasing trend in winter.In terms of different vegetation types,shrubs and grasses increased the most significant.(3)From the whole study area,the average annual NDVI was positively correlated with the temperature and the negative correlation with annual precipitation.The correlation between NDVI and temperature in spring,summer,autumn and winter was significantly higher than that in precipitation The The average NDVI of all vegetation types in the study area was positively correlated with the temperature.Only the coniferous forest and shrub had a positive correlation with the precipitation,and the remaining vegetation types were not negatively correlated with the precipitation.(4)The average time of the growing season of the vegetation in Hubei Province was on the 109th day,and the growing season was on the 28th day.The length of the growing season was 177 days.In the variation of phenological parameters of different vegetation types,only the beginning date of the swamp vegetation growth season was delayed,and the other vegetation types showed an early trend.And the end of the growing season of all vegetation types is in advance,and therefore the growth season of all vegetation types is shortened.(5)As a whole,during the period from 1982 to 2015,the effect of temperature on the phenology of vegetation is stronger than that of precipitation.When the temperature rises,the SOS will be delayed and the EOS will be delayed.The increase of precipitation will lead to the delay of SOS.The SOS of vegetation with higher latitude or higher altitude is more sensitive to temperature.Precipitation has no obvious effect on vegetation growth,but autumn and winter precipitation play a strong inhibitory effect on vegetation growth.