NDVI forest cover changes at high altitudes of the Sulaymaniyah Governorate of Kurdistan Region, northern Iraq, 1984−2021

Abstract

ABSTRACT This study aims to demonstrate the extent of forest cover at high altitudes in Sulaymaniyah Governorate (Province) in the Kurdistan Region in northern Iraq, from 1984 to 2021 and discuss and explain the changes. The forest data were collected from the satellite digital images of the Landsat Thematic Mapper (TM) from 1984 to 2008 and Landsat Operational Land Imager (OLI) from 2014 to 2021. Data preprocessing preparation included employing a radiometric calibration to convert the images from radiance to Top Atmospheric Reflectance (TOA) in order to remove the cosine effect of different solar zenith angles. Next, a quick atmospheric correction (QUAC) was applied to remove atmospheric noise, particles, molecules and vapor from the data; then the basic equation of Normalized Difference Vegetation Index (NDVI) was applied to extract the forest data for 98 samples taken from across the study area. The study shows that forest cover more than doubled during the survey period: in 1984, 9.1% of the study area was covered by forest, but by 2021 forest cover had increased to 18.4%. We discuss how this increase in forest cover is related to better forest management and preservation by the government and by improving the population’s environmental awareness.