Disponibilidade de água em bacias hidrográficas para a vegetação usando NDWI

Environmental indicators are important mechanisms to get information about the state of the environment, in particular water, which is a natural resource of great importance, whose quality it depend of human activities developed in the Watershed. Among the methods and techniques of image processing in order to hydrological analysis, we highlight the Normalized Difference Water Index (NDWI), a method has been instrumental in identifying and monitoring degraded areas and to support studies and proposals for environmental restoration. Therefore, this study adapted the NDWI so that it could reflect the availability of water for the present vegetation in the Una River Watershed, using in your calculation, scientific and technical bases of geoprocessing techniques. From the results, we found that the highest concentration of water stress in the vegetation is present in urban and agricultural areas, where vegetation have to compete with human activities for water availability. In general, the NDWI values were high, since all values are above 0.8, indicating that the study area does not suffer from water scarcity available for vegetation. This indicator allows numerically interpretation of water availability for vegetation in the Una River watershed, and thus a fast, simple and valid alternative for assessing the sustainability of the water, and can serve as a decision-making tool for public managers and stakeholders on this issue.