Risk map of coastal erosion and gravitational mass movements of the Brazilian eastern coast: a Case Study of Pipa Beach/RN

Abstract

The eastern coast of Rio Grande do Norte state (RN) is outlined by the Barreira's Group active cliffs domain and its sandy beaches, which are intercepted by lagoon, river's outlets and estuaries. The Pipa beach, in Tibau do Sul, is situated within the mentioned geological-geomorphological context, where socioeconomic activities are strongly linked to tourism. Subjected to intense coastal dynamics and activities, disasters have been occurring in the region can be attributed to inadequate use and occupation of urban lands, as well as to poor public political decisions. This study presents the Risk Map of coastal erosion and gravitational mass movements for the urban coastal extent of Pipa Beach/RN, which has been prepared by the integrated analysis with a Geographic Information System of spatial data of the physical environment, rainfall, reanalysis of the waves regime and inadequately installed infrastructure. Results showed domain sectors categorized as high risk (R3) and very high risk (R4), and risky points regards to imminent desasters, which were confirmed during field visits. The Risk Map provided a compreheension of the synergy between continental and oceanic processes active in the retreat of the coastline, and subsidies for coastal environmental control and planning, and guiding decision making regards adequate intervention for disasters reduction.