Fragilidade ambiental da bacia hidrográfica do Rio Seridó (RN/PB Brasil)

There are many applications coming from geomorphological studies and their different constitutive and inter related elements, to the implementation of public politics of planning and environmental management. This search presents an analysis of the environmental fragility of the watershed of Seridó River, situated between the states of Paraíba and Rio Grande do Norte (Brazil), including the identification of possible unstable areas. It is based on the methodological approach of Ecodynamics of the French researcher J. Tricart (1977) and on the operalisation proposal advocated by the Brazilian J. Ross (1994), related to the Potential and Emerging Ecodynamic Units, grounded in the Relief s Dissection Index or the topographic roughness, soil, rainfall and land use/vegetal cover. Under a quantitative perspective, the results obtained from the analysis of the watershed can be divided into classes of potential fragility: around 2.613,0 km² of low intensity, 5.188,4 km² of medium intensity and 2.585,5 km² of high intensity. Concerning the emerging fragility, the results are close to 2.212,0 km² of low intensity, 6.191,23 km² of medium intensity and 2.062,34 km² of high intensity. In the case of the watershed in question, the environmental degradation is particularly effective in the areas more dissected, where the ecological conditions, in synergy the environmental degradation, prevent the regeneration of vegetation when arises an opportunity for the (re)establishment of its equilibrium tenuous. The collected data is relevant for the territorial and environmental planning of the watershed, once we can still verify a close association of the cities on the central area of desertification with the areas of high environmental instability/fragility. This is an important tool to the understanding of the potential susceptibility of the natural and anthropic environments related to the advance and/or intensification of the erosion process, rock falls, mass movements, among other phenomena inside the potential unstable areas. From this perspective, the continuity of this research becomes extremely important to the understanding and arrangement of the process, together with the engendering and sustainability of the system in its totality; in narrow correlation because their potentialities, constraints and alternatives on Seridó River watershed, and in all the semi-arid region with similar characteristics

Vulnerabilidade socioambiental no município de Natal, RN

Contemporary society lives surrounded by various types of risks, causing individuals to be taken by a constant feeling of fear and insecurity, as the negative risks, always bring some harm to the population directly or indirectly involved. The city of Natal has several risk areas, especially on the outskirts of the city, due to the occupation of spaces that have laws and / or natural physical limitations as well as the lack of urban organization, thus increasing the vulnerability of the population living in these areas. The principal objective of this research was to map the areas of social vulnerability and natural hazards in Natal, taking into account the interrelationships between social vulnerability and differential exposure to natural hazards. Therefore, it was necessary to establish, according to the methodology used, the degree of social vulnerability and vulnerability to natural hazard in which individuals are subject, to establish the relationship between society/ risks. In this case, the methodology proposed by Crepani (2001) which is based on ecodynamic Tricart (1977), which classifies the areas of risk and the degree of vulnerability of these areas according to the morphodynamic processes for preparation of the Vulnerability Index was used Physical natural, and for organizing the social Vulnerability Index adopted an adaptation of the Paulista social Vulnerability Index, prepared by SEADE (Fundação Sistema Estadual de Análise de Dados) of the State of São Paulo, drawing on data that denote social disadvantage at the census tract level. Then, with the superposition of these two indices, it was elaborated a Socioenvironmental Vulnerability Index. Thus, it is concluded that besides spatialize areas of risk which indicates the degree of vulnerability of individuals potentially exposed to natural hazard.