Diplomarbeit. zur Erlangung des akademischen Grades Diplomingenieur für Kartographie

Transcription

1 Falkultät Forst-, Geo- und Hydrowissenschaften, Institut für Kartographie Diplomarbeit zur Erlangung des akademischen Grades Diplomingenieur für Kartographie Combination of Remote Sensing and Socio-Economic Data for Population Estimation and Monitoring Case study of the Bisiye Mining Site, Democratic Republic of the Congo Christin Abel Kartographie 2006 (Geboren am 21. August 1987 in Wernigerode) Erstgutachter: Prof. Dr. Manfred Buchroithner, TU Dresden Zweitgutachter: Dr. Elisabeth Schöpfer, DLR Dresden, August 22, 2012

2 Contents List of Tables 8 List of Figures 9 List of Abbreviations 11 1 Introduction 13 2 Country Context and Study Area Introduction Democratic Republic of the Congo Geography Climate Geology Economy Historical Context and Recent Development Mining and Conflict in North Kivu Artisanal and Small-Scale Mining and Mining Conditions Conflict minerals Mining Ban (September 2010 March 2011) Study Area Bisiye, North Kivu Remote Sensing and Socio-Economic Data Remote Sensing Data Satellites and Characteristics Satellite Data Socio-Economic Data

3 Contents 4 Analysis Methodology Pre-processing Pre-Selection: Supervised Classification and Accuracy Assessment Detection of Detached Houses and Change Detection Derivation of House Categories Population Estimation Visualisation Bisiye Fact Sheet An Analogue Approach ArcGIS Viewer for Flex An Interactive Approach Results and Discussion 68 6 Summary and Conclusion 82 References 85 Appendix 91 7

4 1 Introduction The today s situation of the Democratic Republic of the Congo is considerable serious: according to various indices such as the Human Development Index or the Failed State Index, the country ranks among the poorest nations in the world. However, in the sense of mineral wealth the DR Congo and especially its eastern provinces are rich in mainly rare and valuable minerals such as coltan and cassiterite. As is arises from the country s history the government has always been weak and absent in these regions which are located remotely in the dense rain forest. Thus, military and rebel groups easily assumed power and begun to exploit both the nature and the population which lives in insecurity and instability thereby. There are various international and largely non-governmental organisations (NGO) which focus their research on the relation between mining and military control. However, potential political interventions for efficient measures and regulations can only be conducted if reliable information about the present situation is available. Remote sensing offers the possibility to monitor the respective (mining) regions where on-site observations are not feasible without a residual risk for the field teams. However, an effective monitoring requires very high resolution satellite data just as expert knowledge for analysis and interpretation purposes. This study results from the EU sponsored project G-MOSAIC (GMES services for Management of Operations, Situation Awareness and Intelligence for regional Crises). Within this project methods and pilot services have been developed to support both intelligence and early warning as well as crisis management and operations. The illegal mining pilot service which is coordinated by the German Aerospace Center (DLR), aims at the provision of relevant information to contribute to focused reactions during 13

5 1 Introduction conflicts and to support rapid identification of affected areas [G-MOSAIC, 2010]. In this context, the detection of potential mining sites started at DLR. Build upon that research the idea emerged to incorporate additional information such as population figures into the analyses, investigate potential relations or discrepancies and assume reasons for that. Thus, information is either acquirable from the satellite imagery itself or can be provided by additional sources such as NGOs and further both can be edited, linked, or integrated either directly or indirectly using data integration approaches. In that regard the main objective of this study is to clarify the following questions: Is satellite derived information suitable to monitor and assess on-site activities as well as to assess certain information provided by official organisations, using the example of population figures? Could integrated additional information create added value to the analyses and if at all, in what way? How can the results be best presented to the user? Against the background of the mining ban in the eastern provinces of the DR Congo which has been imposed in the fall of 2010 and subsequently lifted in March 2011, the Bisiye cassiterite mine in North Kivu has been chosen as appropriate study area to investigate the above defined issues. In this context the population of the Bisiye region is estimated for three different points of time and from different assumptions or sources. The earth observation data sets provided for this study include a time-series of three very high resolution satellite imageries. GeoEye-1 images were available for April and September 2010 and additionally an IKONOS scene was acquired for March The present study is structured into six chapters. The first chapter introduces the Democratic Republic of the Congo, giving a brief overview on the country s geography, climate, geology, economy and history. This is important to outline and to understand the today s complex situation which is prone to conflict and characterised by instability and insecurity. Further this chapter focuses on the 14

6 1 Introduction mining and conflict situation especially in the eastern province of the DR Congo and introduces the study area. The subsequent chapter presents the data basis which is both remote sensing and socio-economic data. An overview of the acquired satellite data and its characteristics is given just as a short review on available literature concerning statistical and other socio-economic information regarding the study area. The main focus of this study is covered by chapter four. Within this section, the methodological approaches of the population estimation and monitoring as well as the different visualisation approaches are presented. Finally, the results of the analysis are exposed and discussed in chapter five. Chapter six summarises the results and their critical reflection and gives a brief outlook. 15

7 6 Summary and Conclusion Build upon the G-MOSAIC project, in the context of potential mining site detection in the eastern provinces of the DR Congo the aim of the present study was to incorporate additional information into spatial analyses, investigate potential relations or discrepancies and assume reasons for that, if possible. Therefore, information from EO Data and additional sources such as NGOs have been acquired, edited, and integrated either directly or indirectly using direct and indirect data integration approaches. In that regard one main objective of the study was to investigate if satellite derived information is suitable to monitor and assess on-site activities as well as to link certain information provided by official organisations, using the example of population figures. Moreover, it was to be clarified whether integrated additional information create added value to the analyses and if at all, in what way. The final objective addresses the most qualified visualisation method of the results. On that account a time-series of three very high resolution satellite imageries of the Bisiye mining site and its surroundings have been provided for this study. GeoEye-1 images were available for April and September 2010 and additionally an IKONOS scene was acquired for March In the course of the stated emphases several information has been gathered from literature research. To these belong population figures according to various sources, the population structure as well as mining and export volume. Besides, further information have been acquired from the provided optical EO Data. For one thing, that contains the digitisation of single houses and their subsequent attribution by means of the additional statistical information, and for another thing the capture of 82

8 6 Summary and Conclusion the potential mining area. Hence, changes of both the houses and the mining area have been derived and displayed. Previously, a rough image classification of the first GeoEye-1 scene has been implemented using supervised methods to obtain a first overview of the situation and to compare the results to the manually received results in retrospect. In an interaction of satellite derived information regarding the single houses and various additional information about the amount of people living in one house, a population estimation has been conducted for all three points of time. Subsequently, all acquired information has been integrated either directly or indirectly into the satellite data and has been visualised. Aiming for an appealing and condensed cartographic product the presentation of the results has been conducted in two different ways: On the one hand an analogue possibility in the form of a fact sheet has been composed, and on the other hand an interactive web mapping application has been realised with the help of the ArcGIS Viewer for Flex. A combination of remote sensing and socio-economic data concerning population monitoring proved useful and sensible in the study s context. For one thing, this can be proved by the fact that the population estimation became only possible when satellite derived information - the single houses, have been complemented with statistical data - people living per house. Besides, information which cannot be combined or integrated directly into a map or the satellite data can be linked to the latter instead. This indirect integration happens by adding figures, tables or diagrams to the spatial data. This procedure also created added value to the effect that additional information such as population structure, production or background information help the user to get a more precise view on the overall situation. Moreover, the consequences of the recent mining ban can mainly be observed by the changes of the settlement area and population number around the mining site. Although any activities did not stop completely there are noticeable changes in the mining sector. The investigation of the further development should be done in the 83

9 6 Summary and Conclusion context of a subsequent study. It is useful to analyse further satellite data, preferably in a half-annual time frame to ensure consistency and to collect additional statistical data concerning the actual respectively international impact of the mining ban. The question of sustainability of the measures and their impacts has to be clarified. It can be stated that in this concrete situation, satellite data definitely created added value, to the effect that important information about the present situation are only available through remote sensing techniques, since on-site observations are not feasible without a residual risk for the field teams. However, on the other hand the reliability of the gathered information could not have been proved. Due to that fact the proposed methodology admittedly could provide further information about the exploitation of natural resources and related settlements, but is not suited to draw conclusions about involved conflicts and reasons for changes in the area. Ground truth of the analysed areas is indispensable. 84