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Joint Earth Seminar: Reza Khatami - Characterizing land cover and vegetation dynamics using earth...

Friday, February 05, 2021, 12:00PM - 1:00PM

Speaker

Reza Khatami

Geography is hosting this iteration of the Joint Earth Seminar Series.

Full title

Characterizing land cover and vegetation dynamics using earth observation systems

Abstract

Knowledge of land-cover/use and vegetation cover is a prerequisite of many studies on drivers of land change, impacts on climate, and other ecosystem services, and allows for sufficient planning and management. This presentation is focused on two example applications of earth observation systems to map and quantify land-cover and vegetation change at national and global scales. (i) Quantification of recent land cover changes in Ethiopia: Agricultural land acquisitions represent large-scale changes in land use to intensive agricultural production, thereby changing the composition and structure of the landscape. Ethiopia has been a primary target country for land acquisitions, with the highest percentage of total land grabbed among sub-Saharan African countries. However, accurate and consistent coverages of land cover/change at the national scale do not exist for Ethiopia. In this work, national land-cover maps of Ethiopia were produced for 2006 and 2017. Land-cover/change area estimation and map accuracy assessment were performed using a probability sampling method and a model-assisted estimator. (ii) Latitudes and Land Use: Global biome shifts in greenness persistence across four decades: Global greening is a phenomenon observed over the last several decades via vegetation health metrics derived from satellite data, such as the Normalized Difference Vegetation Index (NDVI). This global study focuses on the analysis of a statistically robust metric of seasonal directional persistence, which is a net accumulation of directional change in NDVI, throughout 1982-2020 using AVHRR and MODIS data. A per-pixel statistical test was performed to identify pixels with significant NDVI change. Results are reported based on different biomes and land covers.