In: Wagner W., Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
In: Wag 
62 
MAPPING WETLAND ENVIRONMENTS IN THE BRAZILIAN 
SAVANNAH FROM HIGH RESOLUTION IKONOS IMAGE DATA 
I. Barbosa ab 
a Federal University of Minas Gerais, Geo science Institute, 31270-901, Belo Horizonte, Brazil. 
b State Forest Institute of Minas Gerais - Biodiversity Management, Belo Horizonte, Brazil 
Commission VI, WG VI/4 
KEY WORDS: Classification, High resolution, IKONOS, Land Cover, Texture, Vegetation, Wetlands 
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ABSTRACT: 
Wetlands are complex ecosystems hosting a high diversity of landscape associated with water, soil and vegetation 
variations. It provides several essential resources for wildlife and human populations and supports a miscellany of 
aquatic plant species. The Pandeiros Wildlife Sanctuary is a unique wetland ecosystem surrounded by semiarid 
savannas. It supports large communities of macrophytes and terrestrial plants and stores large quaqntities of organic 
matter. In this article we propose a methodology for classifying these wetlands using their spectral and textural 
signature extracted from Ikonos image data. The main plant communities were identified from low altitude photographs 
acquired with a microlight aircraft. Ground data also complemented these photographic records. Classification trials 
were made using both spectral and spatial feature (texture) to assess the most appropriate approach. As a result five 
classes of macrophytes (as dominant specie) and four terrestrial classes were identified with an accuracy of over 80%. 
Texture data brought a significant improvement to the classification. 
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Les zones humides sont des écosystèmes complexes accueillant une grande diversité de paysages associée à l'eau, aux 
sols et aux variations de la végétation. Il offre plusieurs ressources essentielles pour la faune et les populations 
humaines et soutient une grande variété d’espèces de plantes aquatiques. Le Refuge Faunique du Pandeiros est un 
écosystème humide unique entouré par la savane semi-aride. Il supporte de grandes communautés de macrophytes et 
les plantes terrestres et une quantité importante de matière organique. Dans cet article, nous proposons une 
méthodologie de classification de ces zones humides basée sur leur signature spectrale et texturale extraite à partir des 
données d'image Ikonos. Les principales communautés végétales ont été identifiées à partir de photographies à faible 
altitude acquise avec un ULM. Des données au sol ont également complété ces documents photographiques. Des essais 
de classification ont été faits en utilisant les caractéristiques spatiales et spectrales (texture) pour évaluer l'approche la 
plus appropriée. En conséquence cinq classes de macrophytes (comme espèce dominante) et quatre classes terrestres 
ont été identifiés avec une précision de plus de 85%. Les données de texture ont apporté une amélioration significative 
à la classification. 
1. INTRODUCTION 
Wetlands were previously seen as dirty, dangerous and 
unimportant areas by most Western communities (Gooselink, 
2003). Since the Ramsar Convention, a new perception of those 
environments spread through Occident. Several governments 
agreed in built a framework for the conservation and wise use 
of these areas (Ramsar 2006). Brazil is one of the signatory 
parties of the convention and holds numerous wetlands in its 
territory. 
Although Brazil recognize the importance of Wetlands, a lack 
of definition and specific protecting laws threat this 
environments. Due to this absence, we adopted the Canada’s 
National Weltands Working Group (1997) concept which 
considers wetlands areas saturated by water long enough to 
support aquatic process as indicated by aquatic vegetation, 
poorly drained soils and biological activity adapted to this 
particular conditions. 
The Pandeiros River Flood Plain presents all this characteristics 
and is considered an important wetland site in Brazil. It is even 
more special since it is located in a region of water scarcity 
surrounded by savanna vegetation. It provides several 
ecosystem services such as recycling nutrients, fixing carbon 
and recharging the aquifer. Due to its relevance the State 
Government acknowledged this site as a Wildlife Sanctuary. 
However, the recognition as a protected area does not ensure 
the preservation of this region. Large areas still been used to 
raise cattle and several small ones are drained and used by 
communities for family farming (Barbosa, 2009). 
Since it is a unique site in Brazil, identifying types of wetlands 
found in this environment will subsidized its proper 
management and conservation. Nevertheless, this task is a 
challenge since Pandeiros host a complex ecosystem with a 
high diversity of landscapes. 
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