Font Size: a A A

Study On The Change Of Vegetation Cover In Hefei Based On NDVI Data And Its Response To Climate Factors

Posted on:2021-01-10Degree:MasterType:Thesis
Country:ChinaCandidate:Y X WangFull Text:PDF
GTID:2370330611490419Subject:Environmental engineering
Abstract/Summary:PDF Full Text Request
A series of climatic and environmental disasters caused by global warming and climate change have become a widespread concern of scholars in the field of environmental science,ecology and climatology.Among them,the extreme drought,rainstorm and flood disasters in some areas have brought social and ecological problems that cannot be ignored.As a producer,vegetation is an important component of terrestrial ecosystem and can reflect global ecological environment changes.Both at home and abroad,studies on vegetation change and its relation to climate change mainly focus on areas that are relatively sensitive to climate change.This study is a representative study of vegetation cover change and climate change in this region under the trend of global climate change.Through the combination of remote sensing,geographic information system technology,knowledge and methods of ecology,environmental science and statistics,the series of meteorological factors such as temperature,precipitation and NDVI data were studied for many years.The study on the sensitivity of vegetation cover change and climate factors in Hefei can provide a good reference for improving vegetation growth environment,mitigating climate change and environmental protection in Hefei.Based on the NDVI images and relevant statistical data of vegetation coverage in Hefei from 2000 to 2015,as well as the temperature and precipitation data of Hefei in the same period,this paper studies the FVC variation trend and climate change characteristics of Hefei by using GIS technology,unitary linear regression analysis,correlation analysis and spatial interpolation.The meteorological data of the same period are selected,the raster image data of meteorological factors in the study area are processed,and the meteorological changes are analyzed.The correlation between FVC and climate factors in the study area was calculated,and the response relationship between meteorological factors and FVC in Hefei was further analyzed.The following main results were achieved:(1)From 2000 to 2015,the average value of NDVI area of vegetation coverage inHefei fluctuated and showed an increasing trend;In Hefei,the vegetation coverage is mainly good,and the optimal and general ones occupy a certain scale,while the area of the difference is small,mainly in Chaohu lake and the built-up area.The NDVI value of the vegetation coverage obtained by the statistics in Chaohu lake always tends to 0;(2)In general,the FVC in the study area showed an upward trend with a linear trend of 0.35/16 a,with 74.74% of FVC pixels showing an upward trend and 25.26%of FVC pixels showing a downward trend;(3)The temperature of 2000-2015 in Hefei,precipitation are diverse,16 years,the annual average temperature between 14.6-18.3 degrees Celsius in Hefei,Hefei average annual precipitation change between 584.1-1725.2 mm(mm),the interannual difference is big,the linear trend can be seen that the temperature in Hefei in 16 years,showing a lower trend,but the change is not obvious,precipitation presents increasing trend;(4)The perennial mean value of NDVI for vegetation coverage is negatively correlated with the perennial mean value of precipitation and temperature,which is significant.The positive correlation area between FVC and annual precipitation is much larger than the negative correlation area.The positive correlation between FVC and annual precipitation accounted for 76.4% of the city's total area,while the negative correlation was 23.5%.The positive correlation between FVC and annual average temperature accounted for 68.2% of the city's area,and the negative correlation accounted for 31.8% of the city's area;...
Keywords/Search Tags:Climate change, Climate response, NDVI, Vegetation cover, Hefei
PDF Full Text Request
Related items