Espacialização e avaliação ambiental das nascentes de drenagens do alto curso da bacia hidrográfica do rio Pacoti (Ceará, Brasil)

Abstract

Water, a primordial element for most of the life on the planet, has become a central theme in global discussions. The perception of the finite nature of this resource has led to a search for strategies that contribute to a better management and use of this component provided by nature. Despite the unquestionable need to preserve water resources, the knowledge and efforts aimed at caring for this asset can be considered insufficient in view of the intrinsic importance of this element. Intermediating the complex interaction between surface water and groundwater is the ecosystem function of springs. Also known as springs and/or water eyes, the springs are responsible for the entire water network of the planet, therefore, managing these ecosystems is to contribute to the maintenance and supply of water through rivers, lakes, and ponds. Although they develop a fundamental ecological function in nature, there is a lack of information, especially at the level of detail. Therefore, the present study aimed to contribute to this discussion, with the generation of information from the identification and spatialization of drainage springs and the evaluation of these ecosystems through the application of the Index of Environmental Impact on Springs - IIAN. To configure the study area it was selected the upper course of the drainage basin of the Pacoti River, region of the Baturité massif, given the contribution and strategic importance in the development and public water supply for the capital and the Metropolitan Region of Fortaleza. Furthermore, the data collected can also contribute to the strengthening of the protected areas already existing in the basin area, such as the Environmental Protection Area of Serra de Baturité and the conservation unit, still in the creation study phase, which proposes to protect the areas of the three dams responsible for the population supply, Pacoti, Riachão and Gavião. For better environmental understanding and data management, the classification of typologies of springs proposed by Felippe (2009) was applied. This methodology, supported by the geomorphological basis, provided the recognition of the springs from the form and type of occurrence of exfiltration. After identification, mapping and classification, the degree of environmental protection was analyzed through the implementation of the Index of Environmental Impact in Springs - IIAN, according to Gomes, Melo and Vale (2005), and Felippe (2009). Although limited to visual information of the surface, the results allowed important reflections on the condition of the springs in the context of use and occupation in the upper course of the Pacoti River and the impacts generated on the water network in the region. The mapping of springs is a fundamental step and deserves emphasis within the studies, given that they are small areas and difficult to visualize spatially using methods restricted to the remote. Once identified and mapped, this information can promote a database, favoring monitoring actions, conservation and other services.