Cover Page

QGIS in Remote Sensing Set

coordinated by
André Mariotti

Volume 1

QGIS and Generic Tools

Edited by

Nicolas Baghdadi

Clément Mallet

Mehrez Zribi

images

Introduction

This series, QGIS in Remote Sensing, aims to facilitate the appropriation and operational use of Quantum Geographic Information System (QGIS) software for the specific field of remote sensing. QGIS is an open-source and cross-platform software (Windows, Android, BSD, Linux, Mac OS X, Unix) that has been rapidly developed and steadily adopted over the last 10 years. Thanks to a growing international community of programmers, both in terms of fundamental tools and thematic applications, QGIS is increasingly used with strong and continuous growth in terms of users.

QGIS is regularly improved with many new features to better meet the needs of users. This is accomplished through the integration of a wide range of extensions in geographic information science, e.g., GDAL, GRASS, SAGA, Orfeo ToolBox (OTB), etc. as well as the development of its own QGIS Server, and a real Pythonbased script engine.

This set of four books describes, in the first volume, the operating principle of QGIS and the fundamental libraries most frequently used in image processing and geomatics: GDAL, GRASS, SAGA and OTB. This volume presents numerous core functionalities that will be implemented in several practical cases of remote sensing and spatial analysis presented in the other three volumes of the set: management and processing of raster and vector formats, georeferencing, geoprocessing tools, statistical analysis, spatial analysis (on networks, on surfaces) and classifications, starting from core processing up to visualization and cartographic editing.

Volumes 2 to 4 are devoted entirely to the description of various applications that use spatialized data, mainly satellite images. Each chapter in the four volumes is structured into three parts: (1) description of the application context, (2) methodology, and (3) implementation in QGIS and its libraries. Each of these volumes has a particular thematic flavor. Volume 2 is dedicated to applications in agriculture and forestry Volume 3 includes applications related to land use planning, whereas Volume 4 deals with applications covering water and risk management issues.

The use of GIS is becoming a fundamental tool for the scientific community and the public authorities responsible for the implementation, monitoring and evaluation of public policies. Indeed, GIS have evolved tremendously from systems originally planned for the visualization or representation of spatialized information, and the analysis of maps and related products, to more complete and versatile systems containing the most common tools for image processing and spatial analysis. Nowadays, GIS not only allow us to highlight the research results or an application project, but also to carry out the different stages of creation of the information and the knowledge necessary for these projects. QGIS, through its free and multiplatform philosophy, is a fertile breeding ground for these developments. It is even more so with the new paradigm in remote sensing: today, access to geospatial imagery is facilitated for a large number of actors; the cornerstone of studies, projects and research is becoming the capacity to process this large amount of data.

Consequently, the needs of the user community for teaching materials are very strong and we hope, through the publication of this set of books, to help facilitate the adoption of QGIS for beginners and to help those who already have some previous experience in the use of QGIS and its libraries to broaden their expertise.

Chapter 1 of this volume provides an introduction to QGIS. Four other Chapters (2, 3, 4 and 5) are devoted to the description of different libraries. Chapter 2 presents the GDAL library and its main functionalities, followed by Chapter 3 on GRASS, and Chapter 4 dedicated to SAGA, presenting their main visualization and processing tools. Chapter 5 is devoted to the OTB, mainly oriented toward image processing. Chapter 6 describes the use of Lizmap for the dissemination of an online land-use map, and Chapter 7 describes the two GeoHealth and QuickOSM extensions for health applications.

This work, carried out by scientists of a high technical level, is addressed to students (masters, engineering schools, PhD), engineers and researchers who have already adopted GIS. In addition to the texts of the proposed chapters, readers will have access to the data and tools allowing the complete realization of the scientific procedure described in each chapter, as well as access to screenshots of all the windows illustrating each step necessary to the realization of each application. Through this educational work, we hope to contribute to the appropriation of this tool for remote sensing purposes.

A supplement to the chapters, including databases and screenshots illustrating the practical application of the chapters, is available at the following address:

Using Internet Explorer: ftp://193.49.41.230

Using a FileZilla client: 193.49.41.230

Username: vol1_en

Password: 1loe34Nv@

We would like to thank everyone who contributed to the preparation of this book, first of all the authors of the chapters of course, but also the experts of the reading committee for their feedback on the chapters, the exercises, and the corrections made. This project was carried out thanks to the support of IRSTEA (French National Research Institute of Science and Technology for the Environment and Agriculture), CNRS (French National Center for Scientific Research), IGN (National Institute of Geographic and Forest Information) and CNES (French National Center for Space Studies).

We are very grateful to Airbus Defense and Space, CNES and Equipex Geosud for providing us with SPOT 5/6/7 images. Please note that these images may only be used for research and training purposes. Any commercial activity from the data provided is strictly prohibited.

Our thanks also go to our families for their encouragement and to André Mariotti (Professor Emeritus, Pierre and Marie Curie University) and Pierrick Givone (President, IRSTEA) for their encouragement and support for the realization of this project.

Nicolas BAGHDADI

Clément MALLET

Mehrez ZRIBI