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

Vladimir Wingate,Kiran Dhanjal-Adams,Nikolaus Kuhn,Lena Bloemertz,Stuart Phinn

doi:10.3390/rs8080681

Vladimir Wingate, Kiran Dhanjal-Adams + Show 3 more

Open Access

https://doi.org/10.3390/rs8080681

Copy DOI

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 km2. 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.

Highlights

Human activities are altering the surface of the biosphere in profound ways
An accuracy assessment for historical thematic maps is complicated by the fact that only the most recently classified maps can genuinely be compared against temporally coincident validation datasets
This study successfully develops a regional scale analysis of land cover change over four decades in North East (NE) Namibia

Summary

Introduction

Human activities are altering the surface of the biosphere in profound ways. Whether by clearing forests, intensifying cropland production or expanding urban areas, anthropogenic activities have altered an increasingly large proportion of the Earth’s land surface [1]. Maps and datasets which quantify biophysical variables, including land-use and land cover (LULC), are essential for understanding and modelling complex interactions and impacts between the natural and human environments, from regional to global scales. These include processes such as deforestation, Remote Sens. These include processes such as deforestation, Remote Sens. 2016, 8, 681; doi:10.3390/rs8080681 www.mdpi.com/journal/remotesensing

Methods

Results

Conclusion