Avaliação hidormorfológica e paisagística do baixo Rio Jaguaribe na zona costeira do estado da Paraíba

Abstract

The negative impacts caused by the use of process and land use on the banks of rivers and floodplains have been deteriorating the water health conditions, the environment and effect on landscapes. In urban areas, in particular, it is observed the degradation of rivers and water quality and aquatic biota. The interest in restoring ecosystems of waterways, both in urban and rural areas, is expanding worldwide, especially in developed countries. Similarly, areas of occupation in the coastal zone, those which tend to larger and denser occupation, have been a main concern of many governments. Therefore, models of environmental assessment of rivers have been developed and refined to allow the diagnosis and the selection of river restoration actions. The German method, called Mapping and assessment methods for the structure of Waters, developed in Bavaria, is used to map the quality of watercourses structure as a measure of its ecological integrity and indicates whether it is capable of supporting the dynamic processes of its bed. For the coastal zone, the Orla project’s methodology, developed by the Ministry of Environment of Brazil, uses the landscape units as elements of analysis in terms of urban occupation and provides grants for landscape analysis beyond the river limits and may complement fluvial analysis. Both methodologies contribute to perform a broader diagnosis of the current situation of environmental degradation, and may indicate which stretches and landscape units would need intervention to seek restoration or rehabilitation of these areas. In this work, these models were used to map the quality of the riverbed structure concerning its morphology, including the dynamics of the main river and the dynamics of wetlands, and also the marginal areas of low Jaguaribe River in its bed in the municipalities of João Pessoa and Cabedelo, on the south coast of the state of Paraíba. The results showed stretches of the river ranging from a totally altered state to little changed, concerning the stretch and the side occupation of the river channel. The extended marginal areas were classified into three types A, B, C of the Orla project, showing conformity with the classification obtained from the river system.