A qualitative assessment of desertification change in the Tarfaya basin (Morocco) using panchromatic data of Landsat ETM+ and oli: sand encroachment approach

Ali Aydda,Ahmed Algouti,Abdellah Algouti,A Shanableh,M Maalej,R Al-Ruzouq,S Barakat,K Hamad,M Omar,S Al-Toubat

doi:10.1051/matecconf/201712009002

Abstract

The purpose of the present work is to assess desertification change in the Tarfaya basin (Morocco) based on quantifying sand dunes mass change at the corridor scale using two Panchromatic bands of Landsat ETM + and OLI with 15 m of resolution covering the study area for ten years (2005–2016). In this work, the sand dunes quantification is qualitative and is based on automatic extraction and classification of sand dunes shape using co-occurence texture filters and Support Vector Machine (SVM) classifier. The statistical results show that the area covered by sand was increased during the last ten years, which reveal that desertification becomes more intense.

Highlights

Desertification is one of the most common and severe environmental problems in the world
Two scenes of Landsat ETM+ and Operational Land Imager (OLI) covering the study area for ten years were obtained from two different data sources at no charge, which are processed by the Level 1 Product Generation System (LPGS)
The classification is the step; it was adopted for same data sets of combined filters by delimiting polygons around barchans and space between them (Figure 6), and was executed using Support Vector Machine (SVM) classifier

Summary

Introduction

Desertification is one of the most common and severe environmental problems in the world. Several studies have shown the importance of remotely sensed data to quantify desertification change at a large scale for long and short time period. The majority of these studies have been focused on green mass (vegetation) [3,4,5]. Where the sand presents a high spectral reflectance than vegetation in the desert areas (Figure 1), other studies have been concentrated on this material to quantify and track sand dunes encroachment variability with time in order to assess and track desertification [6,7,8]. The sand mass quantification is qualitative and is based on automatic extraction and classification of sand dunes shape from two Panchromatic bands of Landsat ETM+ and OLI using cooccurence texture filters and Support Vector Machine (SVM) classifier

Study area

Data and methodology

Results and discussion

Conclusions