**1. Introduction**

462 Remote Sensing – Applications

Vermeulen, F. & Verhoeven, G. (2004). The contribution of aerial photography and field

Wu X., Sullivan T. J. & Heidinger K. A. (2010). Operational calibration of the Advanced Very

Zollner, H.; Kniess, R. & Meyer, C. (2011). Efficient Large-scale Magnetic Prospection Using

Canadian *Journal of Remote Sensing*, 36 (5), 602–616.

*Archaeol.*, *17*, 57-82.

survey to thestudy of urbanization in the Potenza valley (Picenum). *J. Roman* 

High Resolution Radiometer (AVHRR) visible and near-infrared channels.

Multichannel Fluxgate Arrays and the New Digitizer LEA D2, in Archaeological Prospection - Extended Abstracts, ed. by M. G. Drahor & M. A. Berge, 9th *International Conference of Archaeological Prospection*, Izmir, Turkey, pp. 201-203.

> The study of urban growth in Kinshasa is not a new topic, as shown by the work on the dynamics of housing in the 1970s (Flouriot et al., 1975; Pain, 1978). These authors followed the spatial extension of Kinshasa by collecting old cartographic documents and comparing them. Flouriot (1975) combined a cartographic approach with household surveys to follow the long-term housing growth.

> The advent and development of remote sensing and Geographic Information Systems (GIS) have changed the methods, making it now possible to map and quantify urban growth quickly and easily. More recently in Kinshasa, Tshibangu et al. (1997) have integrated into a GIS a vegetation map drawn by Compere in 1960. This was possible thanks to the interpretation of aerial photographs and Landsat and SPOT images conducted respectively in 1982 by Wilmet and 1987 by Nsekera to quantify the urban sprawl. Delbart and Wolff (2002) evaluated the extension of the city of Kinshasa from an old map (1969) and the delineation of the city in 1995 observed on a SPOT image (from 1995). The current extension of the city (between 1995 and 2005) is not precisely known, but the figures are around 600km² (Lelo Nzuzi, 2008). The purpose of this chapter is to map and quantify urban growth between 1995 and 2005 using a time series of high resolution satellite images.

#### **2. Study area**

The city of Kinshasa province, located between 4 ° and 5 ° south and between 15 ° and 17 ° east, is the largest city in the Democratic Republic of Congo. It covers an area of 9965 km2 (De Saint Moulin, 2005), about 600 km2 being only urbanized. The city had 400,000 inhabitants in 1960 and reached more than six million in 2008, the average annual growth rate between 1960 and 2003 would therefore be about 6.80% (Lelo Nzuzi, 2008).

Kinshasa has grown in the plains bordering the Congo River. The plain 300 metres above sea level covers about 200 km2. This is the most industrialized area and formerly the most

The Mapping of the Urban Growth of Kinshasa (DRC)

the amount and the nature of these changes are derived.

**4.1 Geometric correction and cutting recovery images** 

**4. Methodology** 

geometrical point of view.

suitable for a detect changes study.

Image Cell (m) Control points

Table 1. RMS errors after geometric correction

were cut to the same extension.

zone 33 south.

Spot panchromatic 1995

Spot multispectral

Spot multispectral

Through High Resolution Remote Sensing Between 1995 and 2005 465

Two approaches for change detection exist. "Image-image" comparison methods imply a radiometric normalization; this standardization is difficult to implement on data from different seasons and radiometric quality is also variable (Singh, 1986; Alphan, 2003; Coppin et al., 2004; Yuan et al., 2005). In addition, they do not identify the nature of change. Comparison methods compare the post-classification classifications of land produced independently at different dates (Gupta et al., 1985). The other group of methods is less sensitive to differences in season and they identify the nature of change but are susceptible to misclassification. To detect changes, classifications are compared in pairs. From this comparison, a map where the changes can be located and a change matrix that summarizes

To detect changes, it is essential that the SPOT images are properly stowed from the

This is why the latest panchromatic image has been corrected from an image of higher resolution. This is a panchromatic IKONOS image from 2002 of a resolution of 1 m corrected itself with control points measured in absolute mode with a Garmin GP60 GPS. Root mean

Then all the other images SPOT (panchromatic and multispectral mode) were corrected on the panchromatic SPOT image, corrected with a polynomial function of first order and the nearest neighbour method. All are projected onto the ellipsoid WGS 84 UTM coordinates,

Geometric corrections lead to RMS errors smaller than the size of a pixel with 29 to 35 control points (Table 1), which is acceptable according to Moller-Jensen (1990) and is

<sup>1995</sup>20 34 0.49 9.8 0.54 10.8

<sup>2005</sup>20 29 0.53 10.6 0.44 8.8

Not all SPOT images have the same spatial extension. In addition, their size being 60 km on each side, is wider than the extension of the city of Kinshasa. The images of 1995 and 2005

XRMS (cell)

10 30 0.44 4.4 0.57 5.7

XRMS (m)

YRMS (cell

YRMS (m)

square errors of 9.46 m on the hilly part and 4.14 m on the plain were obtained.

number

densely inhabited, commonly called the "ville basse" (low city). After independence in 1960, the city has spread into the complex hills surrounding the city and low peaks around 600 m above sea level. This area is mainly occupied by slums, called the "high".
