Temporal and spatial dynamic change analysis of vegetation coverage based on RS and GIS from 2006-2016 in Gannan County

Abstract

Based on the Landsat TM and GF1 image data of 2006, 2011 and 2016, the vegetation coverage of the agro-pastoral ecotone (Gannan County, Heilongjiang Province) was inferred, and the influence of slope on vegetation coverage was explored. Based on RS and GIS technology, the vegetation index and the binary model of the pixel were used to quantitatively obtain the vegetation coverage of the study area, and the temporal and spatial variation characteristics and evolution process of vegetation coverage in 10 years were explored. The relationship between slope and average vegetation coverage was quantitatively analyzed. The results showed that the overall coverage of vegetation cover in the study area was good. The sum ratio of medium-high coverage and high coverage between 2006 and 2016 was 87.29%, 87.18% and 87.10%, respectively. In 2006-2011, the conversion rate of medium-high coverage and high-coverage to medium-high coverage was 55.5% and 76.8%, respectively; In 2011-2016, the conversion between medium-high coverage and high coverage was strong, and the conversion rates between them were 18.16% and 76.83%, respectively; In the past 10 years, the area ratio of the vegetation change stable area was 64.32% and 65.54%, respectively. The area of vegetation degradation between 2006 and 2011 was 277 km2, and the area of vegetation improvement during 2011-2016 was 179 km2. The slope was significantly negatively correlated with the average vegetation coverage area, and its regression model was Y = 1728.453-39.546X.