Mapping Decadal Land Cover Changes in the Woodlands of North Eastern Namibia from 1975 to 2014 Using the Landsat Satellite Archived Data

Abstract

Woodlands and savannahs provide essential ecosystem functions and services to communities. On the African continent, they are widely utilized and converted to subsistence and intensive agriculture or urbanized. This study investigates changes in land cover over four administrative regions of North Eastern Namibia within the Kalahari woodland savannah biome, covering a total of 107,994 km 2 . Land cover is mapped using multi-sensor Landsat imagery at decadal intervals from 1975 to 2014, with a post-classification change detection method. The dominant change observed was a reduction in the area of woodland savannah due to the expansion of agriculture, primarily in the form of small-scale cereal and pastoral production. More specifically, woodland savannah area decreased from 90% of the study area in 1975 to 83% in 2004, and then increased to 86% in 2014, while agricultural land increased from 6% to 12% between 1975 and 2014. We assess land cover changes in relation to towns, villages, rivers and roads and find most changes occurred in proximity to these. In addition, we find that most land cover changes occur within land designated as communally held, followed by state protected land. With widespread changes occurring across the African continent, this study provides important data for understanding drivers of change in the region and their impacts on the distribution of woodland savannahs.

Estimating aboveground woody biomass change in Kalahari woodland: combining field, radar, and optical data sets

“…This region provides the natural resources for the livelihoods of greater part of the Namibian population, yet its spatial and temporal dynamics and associated four vegetation change processes (i.e. deforestation and woodland degradation, woody encroachment, and woodland regrowth) remain poorly quantified (Strohbach 2001;Mendelsohn and El Obeid 2002;Wingate et al 2016;Mendelsohn and el Obeid 2005a;Tian et al 2016). Hence, we use field measurements of AGB in combination with high spatial resolution multi-temporal maps L-band SAR and dry season Landsat vegetation index composites for two periods (2007 and 2015) to define the extent, intensity and severity of these change processes.…”

“…A long standing debate remains as to the sustainability of these land-uses; it is widely believed that commercial farming better manages resources, while communal farming is resulting in a typical "tragedy of the commons" situation (Hardin 1968;Strohbach 2001). Permanent vegetation loss and woody encroachment with the consequent loss of economically important herbaceous layer species, are the principal environmental concerns faced by both farming sectors and these processes are also believed to be impacting conservations areas (Tian et al 2016;Ward 2005;Wingate et al 2016;Ward and Ngairorue 2000). Changes in AGB resulting from deforestation or degradation are often limited to approximately 2 t ha -1 due to lack of mechanical means, while woody encroachment occurs at regional scales (approximately 10,000 ha -1 ) (Wingate et al 2016;De Klerk 2004b).…”

“…Land cleared of woodland for small-scale cultivation and urbanization has increased in extent. For example, cleared land increased from 6% to 12% since 1975, with new roads allowing access to arable land, although land abandonment and vegetation succession also occur (Wingate et al 2016). …”

Trans-Border Trade, Minerals, and Civil War Impacts on Land Use and Land Cover Change in GOMA, Eastern Congo: An Integrated Geospatial Technologies and Political Economy Approach

“…Both Landsat TM images of 1987 and 2010 were acquired during the same month for the sake of comparison. It is a standard practice in the applied geospatial research to gather images during the same period time in order to minimize some discrepancies (Lv, et al [26]; Wingate, et al [51]). …”

Examining Multi-Legend Change Detection in Amazon with Pixel and Region Based Methods

“…Since the first overviews regarding change detection in the 1960s [3], many works in this discipline have been conducted using remote sensing data. Among the recent works, we can cite the monitoring of arid environments [4], shorelines [5] and forests or woodlands [6][7][8][9] as well as detection of urban expansion [10], changes in buildings structure [11], changes in submerged sea grass biomass [12], mapping of landslides [13], damage to cultural heritage sites [14] and the proposition of new methodologies [15][16][17][18][19].…”